THE LAMINATING LINE

BUYER’S GUIDE

GLASTON

How to avoid common

mistakes and succeed
in the glass lamination
business

Finland 2020
 Content
1
FOREWORD AND INTRODUCTION

2
LAMINATED GLASS BASICS

3
GLASS LAMINATION LINE INVESTMENT: WHAT TO CONSIDER?

4
THE MOST CRUCIAL FACTORS TO CONSIDER

5
CHOOSE A LAMINATING LINE THAT SUITS YOUR PRODUCTION NEEDS

6
TYPICAL PITFALLS

7
ASSESSING AND CHOOSING YOUR PARTNER –
THE GOOD QUALITY DILEMMA

8
CHECKLIST FOR A PROFITABLE INVESTMENT
 1
Foreword and
introduction

Welcome to explore The Laminating Line Buyer’s Guide. A

laminating line investment is one of the biggest investments
glass processors can make in their business. This investment
can change the glass processor’s game completely, including
the company’s place in the value chain, its customer base and
the overall earning logic.

During the past 50 years, we have seen hundreds of laminating

line investments – both good and bad. Moreover, we have also
seen our fair share of laminating line modernizations that can
help bring an old laminating line up to today’s standards. We can
openly say that we have had our share of learnings!

We wanted to write this guide to help you learn from what we

now know and help you focus on the correct questions during
your investment process. When you want to make the right
decision, the smartest move is to learn from the people who
have done it before you.

The Laminating Line Buyer’s Guide is your guide to what works

best.
©Glaston Corporation 2020

All rights reserved.

This material may not be reproduced or used in any manner whatsoever
without express written permission of Glaston Corporation.

3
 The purpose of this book
is to give you a framework
on how to:

Gain clarity on what is important

Compare different alternatives
Find the right solution for you

If you are considering or are in the process of acquiring a

laminating line, please read this guidebook. We guarantee
that it will pay back. It does not matter if you are going into the
laminating business for the first time or expanding your capacity.
The facts are worth knowing.
We believe this guidebook will offer clarity for your investment
decisions. It’s your key to a profitable laminating line investment.

To your success,

Riku Färm Jussi Niemioja Tuomo Nuottimäki

Product Manager Senior Research and Area Sales Manager
Innovations Manager

4 ©Glaston Corporation 2020

 2
Laminated glass
basics
Before getting to the actual buyer’s guide, we’ll cover essential
information related to the laminating process. This should provide you
with a more structured picture of the content and terminology used in
this book.

Covering the basics:

■■ Laminating process & laminated glass
■■ Heating technology in a laminating line
■■ Pre-pressing technology in a laminating line
■■ Interlayer types
■■ Importance of pre-processing

2.1. Laminating process &

laminated glass
Laminating process
In the laminating process, two or more glasses are paired together
using an interlayer film. The film acts as a bond between the glasses. A
unit that consists of two or more glasses with one or more interlayers in
between is called a sandwich. The laminating process normally has the
following steps:

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 1 Pre-processing (cutting, grinding, drilling, tempering and more)

2 Washing

3 Assembly & trimming

4 Heating & pressing (de-airing)

5 Autoclaving

All these steps have an effect on the final quality and success rate of
your process. If all steps are not performed correctly, it’s possible to ruin
an otherwise well-optimized process. Possible sources of issues are
covered in more detail later in this book.

After the glasses have been prepared and washed, the sandwich is
assembled, and excess foil is trimmed from the edges. After assembly,
the sandwich is heated. When the desired temperature is reached,
trapped air is removed from between the surfaces by pressing the
sandwich with a nip roll.

After pressing, the pre-laminate is ready to proceed to the last stage of

the process, which is autoclaving. An autoclave is a pressure chamber
where the final lamination happens. This step is performed in about
130 °C under about 13-bar pressure. For small scale production, it is also
possible to laminate glasses using a vacuum bag process. Later in the
book, we will explain this in more detail.

Laminated glass

The use of laminated glass has been growing at a fast pace in the past
years – actually quicker than the use of tempered glass. There are
multiple reasons for this, with safety regulations, strength and design
aspects being the most important ones.

The final laminate has many valuable functionalities, and its safety
features are one of the most important aspects. Even if one of the
glasses in the sandwich breaks, the interlayer still holds the sandwich
together.

6 ©Glaston Corporation 2020

This allows the use of normal float glass as safety glass and provides
higher safety in places where there are risks of glass breakage if it falls
from its frame.

Laminating also provides strength. A laminated glass unit is more

durable than a single glass sheet of equivalent thickness, which gives the
possibility of using lighter glass elements.

In addition, more and more varying designs are driving the use of
laminated glass. Modern architectural designs are more often calling
for complex glazing solutions, and laminated glass provides an answer
to that. It enables the use of different shapes, glass types, colors as well
as interesting applications with smart elements laminated inside the
sandwich.

Last but not least, structural interlayers, an integral part of laminated

glass, are becoming ever more available in the market.

2.2 Heating technologies

The most important part of a laminating line is the heating and pressing
technology used. If the sandwich is not evenly heated to the correct
temperature, the end result will not be good. Glass sandwiches, like any
substance in the world, can be heated using three methods:

■■ Conduction
■■ Radiation
■■ Convection

Conduction happens when two

materials touch each other – a hot
material conducts energy to the other The most important part of a
material. In the laminating process, the
laminating line is the heating and
effect of conduction is very low.
pressing technology used.

7 ©Glaston Corporation 2020

Radiation is a form of heat transfer in which a hot material radiates
energy to its surroundings. Traditionally, laminating lines use infrared
heaters that emit radiation in order to heat the glass.

Things get tricky with radiation when any kind of coating is introduced
to the mix. For example, a Low-E coating reflects radiation efficiently,
whereas a painted surface emits radiation.

In modern buildings, low-emissivity coatings are being used more

commonly in order to optimize the buildings’ energy efficiency – making
the processing of glass more difficult.

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Convection is the third form of heat transfer. Convection implies the
transfer of heat from one place to another by fluids, in this case, air. In a
laminating furnace, the sandwich is heated by a forced air movement.

Convection does not care about the glass type: it forces heat transfer
from the air to the glass. The air molecules simply convey the heat,
taking it from the heaters and transferring it to the glass, which is why
convection is so efficient with all types of glass. Moreover, convection
heats the surface faster than radiation.

Nowadays, laminating furnaces often use a mix of infrared radiation

and convection, which is why such lines are often called hybrid lines.
The main portion of the heating still comes from the infrared heaters,
but assisting convection is used to make it easier to process different
glass types.

Some lines are designed to block any excess radiation as much as

possible. Such lines are often called full convection lines, highlighting
the fact that the main portion of the heat transfer is actually done by
convection – making these furnaces indifferent to the type of coating on
the glass.
Convection is very efficient
Whatever the term used to describe
the heating technology, always
with all types of glass
remember that the sandwich does and heats the surface faster
not know what kind of technology is than radiation.
being used.

However, the sandwich does

quite honestly show you the efficiency of the technology used. So,
concentrate on the impact of technology when evaluating alternatives.

More detailed information about the heating technologies is covered in

chapter 4.3.

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Vacuum bagging
An alternative way of laminating glass is vacuum bagging. This means
that the glasses are wrapped manually in a vacuum bag that is placed
in a heating chamber, and vacuum is created inside the bag. Vacuum
bagging is mostly used with curved glass and EVA foils due to the
delicate nature of the foil. Nevertheless, it can also be used with any
other foil.

The downside of vacuum bagging is very low capacity. It requires a

large amount of manual work, and throughput is much smaller than
with a nip roller line. Moreover, EVA foils are more expensive than PVB
foils.

Vacuum bagging becomes a viable choice

only if the required production capacity is The downside of vacuum
low, and the availability of laminated glass bagging is very low capacity.
for purchase is not sufficient. It requires a large amount of
manual work.
Therefore, this guide focuses on the nip
roll and autoclave process. But note that it
is also possible to use vacuum bags
(or vacuum rings) with an autoclave, if needed.

10 ©Glaston Corporation 2020

2.3 Interlayers: PVB, EVA & SentryGlas®

When it comes to lamination, there is a huge variety of different

interlayers that can be used, from standard interlayers to different
colors, structural and sound insulating interlayers. Which ones you will
need in your production completely depends on the final application of
the product.

Interlayers can be divided into three main segments, based on the

material that is used to manufacture them. The main types are PVB
(polyvinyl butyral), structural interlayers and EVA (ethylene vinyl acetate).
The main interlayer types and their characteristics from the process
and end-use point of view are covered
below.
Interlayers can be divided into
Make sure to consult with your three main categories, based
laminating line and interlayer supplier on their material.
about the special requirements of
the foils you will use and what kind
of effect these might have on your
production.

PVB interlayers

PVB is the most popular material used to laminate glass, even though
alternative materials are gaining ground. PVB provides all the properties
of laminated glass: impact resistance, penetration resistance, sound
control, UV protection and even high UV transmission.

PVB interlayers have evolved a lot during the past few years. For
example, they provide much better UV protection today and exhibit many
other performance improvements.

PVB films can also be divided into interleaved and refrigerated films.
Before interleaved films were introduced, PVB with refrigerated films
had been stored in much stricter climate control conditions. The
temperature had to be below 10 °C, hence the name “refrigerated.”

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Storing the interlayer in a cold environment prevents the foil from
sticking to itself. In an interleaved film, there is a thin plastic sheet
between each layer in the roll, preventing the film from sticking.
Therefore, the interleaved films can be stored at normal room
temperature of around 20 °C, which means easier and more
environmentally friendly transportation and storage of the foil.
Nowadays, most of the PVB films used in architectural applications are
interleaved.

The most modern PVB films can also be made more solid, more stiff and
even suitable for extra-large glass surfaces. The PVB foils also come in
different types, such as acoustic, colored and photovoltaic. Different PVB
foils address a large number of needs and can be applied in different
applications, from interior design to façades. However, even though
PVB performance has been evolving a lot, PVB can still be vulnerable to
external factors, such as exposure to water in open-edge applications.

For most applications, interleaved PVB still provides the best price-
to-performance ratio compared
to other interlayers. PVB is also
In contrast to PVB, the
relatively simple to process, since
the temperature window to achieve appearance and quality
optimal de-airing is larger, for of laminates made with
example, than using structural SentryGlas® remain almost
interlayers.
unaltered, despite exposure to
Structural interlayers changing outdoor conditions.

Structural interlayers, such as

SentryGlas® from Kuraray, feature better stiffness and higher
performance than PVB. Structural interlayers are on average up to 40%
lighter, while offering the same durability as PVB. In contrast to PVB, the
appearance and quality of laminates made with SentryGlas® remain
almost unaltered, despite exposure to changing outdoor conditions.

While SentryGlas® is often the most recognized structural interlayer

brand in the market, most manufacturers have their own brands for
interlayers that provide structural strength to the laminate.

12 ©Glaston Corporation 2020

Structural interlayers widen the scope of applications of laminated glass.
New architectural designs become possible with lighter safety glass and
glass as structural elements. For example, structural interlayers can
be used in applications where traditional laminated glass with a PVB
interlayer would have been too heavy for the supporting structure, such
as tall buildings made almost entirely of glass. They are also a better
solution for extreme applications, such as hurricane-resistant glazing.

As a downside, structural interlayers are more expensive than PVB.

Due to enhanced interlayer strength, the higher cost can, in some cases,
be compensated by being able to reduce the glass thickness. After
all, reduced thickness leads to lower glazing costs and lighter frame
constructions.

Structural interlayers are also typically more demanding in the

lamination process, both in the heating and autoclave cycles. The
temperature window to achieve optimal de-airing is much narrower than
with PVB, which results in tighter heating uniformity requirements for
your laminating furnace.

For autoclaves, running

structural interlayers with
a similar cycle time as PVB The downsides of EVA are higher
normally requires about four interlayer costs and a more
times higher cooling capacity.
labor-intensive process than PVB
Alternatively, you can choose
to run about only ¼ of your processing.
maximum amount of glass in
the cycle. Plus, the autoclave
cycle should be specifically optimized for structural interlayers.

It is also noteworthy that with the introduction of the latest-generation

structural interlayers, the requirement for the autoclave cooling capacity
is starting to come down to the same level as with PVB.

Make sure to consult with the manufacturer of the structural interlayer

about the autoclave cycle time recommendations for the interlayer that
you are using.

13 ©Glaston Corporation 2020

EVA interlayers

EVA interlayers are typically used in small-scale production with vacuum

bagging equipment. EVA interlayers suit this need very well since this
type of film does not require autoclaving after vacuum bagging.
A vacuum bagging furnace offers very limited capacity but also
represents a smaller investment.

The downsides of EVA films are limited capacity, higher interlayer costs
and a more labor-intensive process than with PVB processing.

EVA interlayers are most suitable for applications with exposure to

water and different kinds of decorative applications. EVA has good water
resistance, and it also adheres to different materials better than PVB,
enabling decorative solutions, such as utilizing fabrics or papers in the
laminate.

Like PVB, EVA foils come in many different types, such as acoustic,
colored and photovoltaic.

EVA foils are somewhat limited in roll width, meaning that jumbo glass
lamination is not possible with these foils. Moreover, EVA does not
have enough structural strength, and EVA laminates cannot be used as
structural elements.

Even though EVA is traditionally used with the vacuum bagging process,
it can also be used with a standard laminating line and autoclave. With
the latest heating technology, EVA foils can be run through the furnace
and nip roll with the same settings as PVB foils.

However, the autoclave process with EVA foils differs a bit from PVB.
So, make sure to consult with your laminating line supplier to have the
autoclave process fine-tuned for EVA.

Also, note that the autoclave cycles optimized for EVA will still be longer
than when using PVB. Therefore, this will slightly limit capacity.

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 The core characteristics and differences of the main interlayer types are
presented in the table below.

PVB EVA SENTRYGLAS®

Commercial
Price Low Medium High
Processing cost (€/sqm) Low High (medium with Medium
autoclave process)
Labor intensity Low / medium High Low / medium
Initial investment cost of Medium / high Low (medium and high Medium / high
the equipment with autoclave process)
Applications
Terrace, railing and o o
balcony glazing (limited open-edge (no structural glazing) x
application)
Interior glasses x x o
Windows x x x
Hurricane-resistant x - x
glazing (stiff interlayer)
Bulletproof glasses o o x
Glass façades x x x
(often not cost efficient)
Technical performance
Good, foil color can
UV performance slightly change during Excellent Excellent
decades of use
Limited open-edge
Water resistance application Excellent Excellent
(except for stiff PVB)
Adhesion level Excellent for glass, Excellent for glass and Excellent for glass
adjustable other materials
Colors Available in various Available in various Limited
colors colors
Acoustic performance Good, separate acoustic Good, separate acoustic Normal
PVB available EVA available
Structural performance Good, separate Bad, not suitable for Excellent
structural PVB available structural applications
Excellent
Impact performance (at the lowest possible Limited Good
glass thickness)

15 ©Glaston Corporation 2020

 3
Glass lamination line
investment:
What to consider?
Even though we are in a growing business, it is very important to
thoroughly plan how you are going switch to the new technology and
capabilities in your particular business. Perhaps the most common
scenario is when a company has been purchasing laminated glass
from third-party suppliers and is considering taking the manufacturing
process into its own hands. This provides flexibility and enables higher
margins – but make sure to have a solid business plan before making
the investment decision.

3.1. Project basics

When we talk about investing in a laminating line, we’re talking about
a project that may take up to 1.5 years, from making your business
case to having a line in production. The chart below provides a good
framework when planning your investment and project milestones.

PROJECT PHASES TYPICAL DURATION

Make your business case: Define the requirements for the line
and make sure you have the needed utilities, such as electricity, 1–4 months
available
Compare alternatives:
• Suppliers and technologies 1–4 months
• Factory layout solutions
Select a supplier partner, lock down the layout and make a
1–3 weeks
contract with the supplier
Laminating line delivery time: Total delivery time typically ex-works:
1. Project kick-off 4–10 months
2. Project-specific design Shipping:
3. Manufacturing From a couple days to 6 weeks
4. Shipping to the site Installation and startup:
5. Mechanical and electrical installation 6–10 weeks
6. Startup and commissioning Training:
7. Training 1–2 weeks
Start of production, start of the learning curve 0.5–3 months
Full production and process development for optimal production Ongoing process
TOTAL TYPICAL PROJECT LEAD TIME 10 MONTHS TO 1.5 YEARS

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3.2 Building a solid business case
A business case starts many times by asking why to enter the business
in the first place. This question has everything to do with the business
model you choose. How are you going to differentiate yourself from
competitors, and what is your competitive edge?

Choosing your business model is ultimately a question of how fast your

investment payback time is. On the following pages, we’ll give you a
simple framework, which you can use to analyze the investment in your
business.

Contact your laminating line supplier for more detailed payback and
cost-of-ownership calculations.

The business model you

The two main high-level components
choose can affect how
you need to consider:
fast your investment
will pay back.
1 Estimated production volume

2 The uniqueness of your business model

Go for high production volumes

You can quite easily justify the investment in a laminating line if you
are going to have high production volumes. If your alternative is to buy
laminated glass from existing suppliers, this is a simple math exercise.

If the cost of setting up your own laminating line is lower than the
3-year margin you pay to your suppliers, it usually makes sense to start
laminating yourself.

If you are going for high production volumes, make sure that the
line you choose supports that business model. Key features are the
production pace and yield the line can provide from day to day and year
to year.

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 Differentiate by other means
You don’t necessarily need to go for high production volumes to justify
the investment. Alternatively, your business model can be built around
uniqueness.

The uniqueness of your business model can mean several things.

Analyze your model against that of existing suppliers
and discover your competitive advantage. This will
tell you if entering the business is the right decision. Low production volume
If it provides you with cost savings or better customer can be a success if
value, you will be able to get your investment back
soon, even with lower production quantities.
your business model is
distinctive.

Low production volume, unique business model

Short delivery times Quality of your product

24h
If your model is to provide 24 h delivery Quality screening is an extremely
times to your customers, for example, important phase in your production, and
you are able to charge a higher price. you need to have a process for possible
This raises your profitability and leads rejections. Define how valuable it is
to good payback, even with lower to have this process under your own
production volumes. control. If you have a high amount of
rejections from your current suppliers,
Short delivery times also underline the or your suppliers do not meet the
need to control the operations yourself. agreed delivery times, you might reach
If you have as short as 24 h deliveries, it better overall performance by having
can be difficult to arrange the delivery this process in your own hands.
process with a third-party processor.

Automated production flow

If you have a highly automated glass
$ Low direct and indirect costs

If you have low direct or indirect

flow in your factory, even lower volumes production costs, including the costs of
will provide you with a good payback, labor, freight or glass, you might be able
because you have lower running costs. to get a satisfactory payback for the
investment, even with lower production
volumes.

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 As a general rule to guide your investment decision, you should evaluate your
investment in these two regards: production volume and business model
uniqueness.

A simple model to help you with your decision-making process is described in the
picture below.

Hot or
Time to invest?
Where is your position? not?
■■ Most probably the time has come ■■ Strong reasons to invest in your own
to invest in your own laminating line laminating line
■■ Payback should be moderately fast ■■ Payback is fast

■■ To reach economy of scale, ■■ If markets fluctuate, revise your

automate everything business model
Production volume

possible related to
processing

■■ Most probably, not yet the time to ■■ Most probably, the time has come to
invest in own laminating line invest in your own laminating line
■■ If your volumes grow, reconsider ■■ Payback should be moderately fast
the investment ■■ To support your business
■■ Scope out if there is any other way to model, build flexibility
differentiate yourself in your production

Business model uniqueness

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 Your checklist before
the purchasing phase:

When you start the project, first recognize the rough

schedule. The project usually takes 1–1.5 years.

Do you have enough production volume to justify the

investment?

What are the other benefits or risks you get from

owning and operating a laminating line in-house? Do
these justify the investment?

How do you see your business model developing in

the future, and how does that change the equation?

Calculate your break-even point. What is the volume

of orders you must have to be successful?

The sky is the limit. Calculate the absolute best-case

scenario and make sure you don’t limit yourself with
your investment.

20 ©Glaston Corporation 2020

 4
The most crucial factors
to consider
4.1. Your business segment
sets the framework
The business segment you are in determines many of the requirements
you need to set up your laminating line performance. For example,
quality and size requirements for façade glass are very different from
those for furniture glass.

This chapter gives you a rough model of how your business sets the
requirements for your laminating line performance.

The questions you need to ask yourself:

1 What is the business you are in today?

2 Can this change in 3–5 years’ time?

3 What are the trends in these segments, and how will

they impact the requirements on your laminating line?

With these questions in mind, we have compiled a checklist that

outlines the requirements and recommendations for your laminating
line performance.

21 ©Glaston Corporation 2020

 BUSINESS MARKET REQUIREMENTS REQUIREMENTS FOR LAMINATING
SEGMENT TECHNOLOGY

Premium-quality architectural glazing

Efficient and energy-saving convection
Low-E coated glass system to eliminate the effect of
coating
Even heating to ensure excellent
High optical quality
laminating quality
Even heating and pre-pressing
Heat-strengthening and
to enable laminating efficiency of
tempering
tempered glass
Large line size. Tilting arms at least
Large glass sizes in the unloading end to support glass
Glass façades lifting
Efficient and energy-saving convection
Painted / screen-printed
system to eliminate the effect of
glass
coating
Convection system to make highly
Versatile glass sizes and
mixed production easy. Line design to
types
support mixed production
Laminating technology that supports
Normal PVB and structural
running different foil types, such as
interlayers
PVB and SentryGlas®
Other architectural applications
Terrace, railing and Medium to thick glasses Sandwich thickness range 8–24 mm
balcony glazing
Tempered glass Even heating and pre-pressing
to enable laminating efficiency of
tempered glass
Glasses with holes Even heating to enable glass with
holes lamination
Windows and doors Low-E coated glass Efficient and energy-saving convection
system to eliminate the effect of
coating
Relatively thin glass Sandwich thickness range 6–12 mm
Interior glass Thin and thick glass Sandwich thickness range 6–30 mm
Painted glass Efficient and energy-saving convection
system to eliminate the effect of
coating
Large selection of PVB foils Easy handling and cutting of PVB.
(colors, thicknesses) Convection heating system that
eliminates the effect of foil color on
the process
Bulletproof glass Thick glasses Sandwich thickness up to 80 mm

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4.2 Production mix and capacity

Your estimated production volume and production mix are the first
questions your laminating line supplier will ask you. Understanding your
production requirements plays a key role in making sure that the line
configured for you meets the requirements.

With laminating lines, the chosen heating technology can have a huge
impact on your actual achievable production capacity. This is critical,
especially if you are planning to run mixed production (different glass
sizes, shapes, coatings, paints and more). With a traditional infrared
heating furnace, you will always have changeover time between product
types. In practice, this means whenever you change the coating or
sandwich thickness, you need to reconfigure your furnace temperatures
and firing levels to suit.

4.3 Choose the correct technologies

When purchasing a laminating line, there are various technological

choices to be made that affect the day-to-day use of the line. The most
important choice is your heating and pre-pressing technology selection.
Other things to take into consideration are mainly related to washing,
ease of use and the automation level of the line.

Remember – whichever technology you end up choosing – always ask to

see the technology in a real production environment with different kinds
of sandwiches! This is an easy way to make sure that the manufacturer’s
claims actually
hold true.
Remember – whichever technology you end up
choosing – always ask to see the technology in a
real production environment with different kinds
of sandwiches!

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Heating & pre-pressing technology
The most critical selection you will make in the purchasing phase is the
heating and pre-pressing technology. When it comes to heating, there
are two main technologies that can be considered: full convection or
infrared + convection heating.

Infrared radiation + convection heating

Still today, most furnaces use radiation technology for lamination.
This can be long-wave infrared radiation or short-wave radiation. The
production challenge in both solutions is the same. Radiation efficiency
depends heavily on the glass type being heated, for instance, Low-E,
clear or painted glass.

Typically, infrared heating is

combined with convection heating. Radiation efficiency depends
But in all of these solutions, heavily on the glass type being
radiation heating still plays a
heated, for instance, Low-E, clear or
larger part in glass heating, which
means that the issue with different painted glass.
glass types still remains.

Often, furnaces with infrared heating technology require a huge

number of recipes for different glass types and sizes. Each change
requires adjustment in multiple furnace parameters, including its
temperature. This surely makes the process unstable, especially in
mixed production. Furnace temperature changes also always require
a reasonable changeover time to reach the new set value before
continuing production.

Another issue with this kind of furnace is that Low-E coatings reflect
radiation and cause the ambient temperature in the furnace to rise.
This causes the laminate sandwich edges to seal too early due to overly
high temperatures along the edges. As a result, the probability of
laminate quality problems increases. To stabilize the process as much
as possible, excess heat is typically vented out of the furnace through
chimneys, which essentially means wasting money.

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Particularly with radiation furnaces, unnecessary waste is often
caused in the lamination process, when not enough or too much heat
is applied. The more glass types need to be processed, the more
complications there are for a machine based on traditional radiation
technology.

Picture 1. Temperature differences in a radiation furnace

1: Painted surface. 2: Low-E surface

The upside of infrared heating is that it can be very efficient in heating

clear glass with no coating. The reason is that infrared heat can mostly
go through the glass and directly to the foil, which can be effective with
single laminates (2 glass panes, 1–2 foils).

In multilayer laminates, however, this can cause the first foil layers to
overheat.

25 ©Glaston Corporation 2020

Full convection technology
An alternative way of heating glass is convection. Full convection
technology offers multiple advantages compared to infrared heating.
These include uniform heating, faster changeover time between
products and higher yield.

The main difference between infrared and full convection heating is

that full convection technology is indifferent to the glass type used. This
means that the results expected from the laminating line should not vary
between the glass types.

Moreover, with full convection technology, there’s no need to adjust

furnace temperature in most cases, which means that when changing
from coating to coating or from thickness to thickness, there will be no
changeover time in between.

Full convection is a very efficient way to heat different glass types. Even
Low-E coatings do not reflect convection heat. An example of this can
be seen in Picture 2, where Low-E and a painted black surface react to
convection heating almost identically. This means that with convection
technology, only the glass itself is being heated. There are no issues with
furnace overheating.

Full convection is a very efficient way to heat

different glass types. Even Low-E coatings do
not reflect convection heat.

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 Picture 2. Temperature difference in a full convection furnace
1: Painted surface. 2: Low-E surface

A convection furnace is typically also much more energy efficient

compared to a radiation (+convection) furnace. Usually, the same or
even higher capacity can be achieved with about half of the connected
power of a radiation + convection line. Energy losses during the
process are also much smaller, as there is no need to vent excess air
from the furnace.

The main practical differences between these two technologies are

visualized below.

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With an infrared + convection line, every product change (whether
it’s glass coating or sandwich thickness) requires adjustments of
the furnace settings. Most often, these changes include the furnace
temperature, resulting in changeover times when waiting for the furnace
temperature to stabilize. In a normal mixed production environment, this
means that managing the production can be very difficult, and extremely
skilled operators are needed to keep the process at least somewhat
stable.

With a full convection

With a full convection furnace, the
furnace, the furnace furnace temperature is not changed
temperature is not changed during normal production, so product
during normal production. changes are very simple.
This means that product
changes are very simple,
just adjusting the furnace
speed to the correct level.

Most importantly, glass coating does not affect the outcome of the
process, since convection is indifferent to the glass type. Adjustments
are only needed when the sandwich thickness or composition is
changed. And normally, these adjustments are still limited to furnace
speed. This helps to make production much more predictable and easier
to use – even for new operators.

Pre-pressing technologies
In a laminating line, heating technology is often a much more discussed
topic than pre-pressing technology. This means that the differences
between various press units might go unnoticed.

In fact, design choices made in relation to the pre-pressing unit can have
a big effect on how easy the press is to operate and how uniform the
pressing result is for different glass sizes and shapes. The most modern
pressing machines have been designed so that the press unit does not
need to be adjusted (even automatically) based on glass width and shape.

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Often, the laminating lines are equipped with two pressing units. The
first press is needed for removing some of the air in the middle of the
process, and the second for removing the air after the actual heating
has been done. In other words, the second press can be used to
somewhat compensate for the inaccuracy of the heating if the process
has not been correctly set up.

Keep in mind that sometimes less is more – a good press design

combined with uniform heating can be sufficient with only one press.
This also has the advantage of not creating a situation of having a long
glass pane under two press units at the same time.

Make sure to discuss with your potential laminating line suppliers what
kind of pressing technology they use. A well-designed pressing unit will
make operation much easier. It also enables better yield in day-to-day
production.

Cleanroom operations
A cleanroom is where most of the manual work happens when the
operators assemble the sandwiches and trim the foil. The functional
and efficient design of this part of the line plays a very important role –
especially in mixed production.

Where to run glass – in the middle or at the edges of

the conveyor?

One aspect that is often different from line to line is whether the glass
is run at the left or right edge of the conveyor – or in the middle.

Traditionally, glass is run at the edge. In practice, this makes the

loading process slightly easier if the operators load glasses mainly
from the side of the line. The downside of running glasses at the edge
is that this method requires a wide assembly and trimming conveyor,
which can make the operator’s work much more difficult. Reaching
to the center of the conveyor can be challenging, especially with wider
lines.

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An alternative way to transfer glass is to run it in the center of the
conveyor. In this case, glass is automatically positioned in the center
before it is transferred to the assembly and trimming conveyor. This
allows the use of a much narrower trimming conveyor, which provides a
much more ergonomic environment for the operators and also leading
to better trim quality.

Glass lifter design

A glass lifter is normally used to move glass inside the cleanroom. The
automatic glass movement offers accurate glass positioning as well
as makes the operators’ lives easier by not having to lift heavy glasses
manually.

Make sure to check with your supplier what kind of positioning accuracy
can be expected from the glass positioning / lifting system of your
potential line.

Remember to check how the glass lifter has been

designed:
■■ Are there structures that are blocking the operators from
accessing the trimming area in day-to-day work?
■■ What kind of maintenance requirements the glass lifter has?
■■ What is the total lifting capacity of the solution?
■■ How is lifting capability ensured for all cases?
■■ How does the glass lifter adapt to different glass sizes or
shapes?

Amount of motorized PVB rolls

The PVB rolls are often stored on top of the assembly area. An
important choice to make here is the number of automated PVB roll
slots in the line.

The ideal number depends completely on the production you are

running. If you are changing the foil type or color often, you would need
to have a larger number of PVB rolls.

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Normally, opting for six to eight motorized rolls is enough for smooth
operations.

Consult with your laminating line supplier to discuss what would be the
optimal amount for your production.

It is also a good idea to consider building an offline storage area inside

the cleanroom. Usually, there is space to build storage on the second
floor next to the automated slots. This makes it easy to switch between
the automated and offline slots and also provides optimal storing
conditions for the PVB rolls.

PVB cutting & trimming

PVB cutting

With modern laminating lines,

the PVB magazine system With modern laminating lines, the PVB
is often equipped with an
magazine system is often equipped with
automatic PVB cutter that
makes a lengthwise cut to the an automatic PVB cutter, making the
foil after the desired amount of whole operation much simpler.
foil has been rolled down from
the magazines.

This kind of system makes the whole operation much simpler for the
operators as foil infeed and cutting are automatically controlled, and
the operators handle only the pre-cut interlayer pieces. Also, this
allows reducing the amount of wasted PVB because exactly the needed
amount is cut.

There are a couple of different solutions for the actual cutter design.
The simplest one is to use a standard carpet knife blade attached to
a moving linear one to make the cut. The downside of the knife blade
solution is that the blade starts to get dull after a short time, affecting
the quality of the cut if the blade is not changed often. For example,
the cut won’t be as clean and can cause some debris to fall from the
system.

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More advanced systems use a spinning blade design that offers a
much cleaner cut, even if the blade gets dull over time. In this case,
the cutting speed might be slightly reduced, but the cutting quality will
remain the same. Usually, these kinds of systems also come with an
integrated cutter sharpening tool to make operation even simpler.

PVB trimming

Normally, the operators manually trim the PVB foil around the edges
of the sandwich after the assembly. There is a range of automatic PVB
trimming applications in the market. The upside of these systems is
the reduced amount of manual work the operator needs to do. But note
that an automatic trimming system does not replace the PVB cutter.
Both are required.

As a downside, the automatic PVB trimming systems often tend to

only work reliably when the glass sizes and shapes do not change.
That means this kind of solution is only truly effective in stock sheet
lamination, where jumbo rectangular glasses are being processed
(see chapter 5.2). For normal mixed production (see chapter 5.1), where
glass sizes and shapes can vary a lot, the automatic trimming solutions
are often not recommended.

Washing technology
Washing the glasses can seem like a trivial operation, but the washing
machine is an extremely important part of a laminating line. Poor
washing or drying results have a direct impact on the final quality of
your products.

The most important factors in a washing machine:

■■ Washing result
■■ Drying result
■■ Ability to handle different glass types with ease
■■ Ease of use, such as automatic adjustment based on glass
thickness

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Make sure to discuss with your supplier what kind of washing machine
they use. A well-designed washing machine will operate automatically
as part of the line without additional manual adjustments during
normal operation.

Also, take into account that the washing machine would most likely
require a water treatment center. Consult with your supplier about the
water quality requirements and about possible options for the water
treatment solutions.

4.4 Optimize your machine size

The most important factor that defines the laminating line bed
dimensions is the glass sizes required in your production.

There are two main criteria:

1 Your or your customer’s maximum glass size requirement

2 Average line length that would allow you to optimize your

capacity

You need to carefully consider these two factors. If you are in the
residential windows business, sizes rarely go over
2100 x 3600 mm. If you are in the commercial façade business,
sizes reach close to 3300 x 6000 mm or even larger in some cases.

Defining the suitable line size for your business is crucial, especially
if you are going for high-volume production. This is because the line
length has a direct effect on the capacity you are able to achieve due to
the longer travel distances of conveyors and glass lifters.

Remember, too, that your line’s footprint will obviously be larger with a
bigger line.

So, if only a very small part of your business is coming from long
glasses, it might be worth considering purchasing those glasses from
somewhere else rather than investing in a larger machine.

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Loading efficiency
The term “loading efficiency” is familiar to the persons running a
tempering line. In a tempering line, the loading efficiency is defined
by how efficiently you can utilize the loading bed. This is because it is
possible to load even multiple glasses in one batch in a tempering line.

Running only one pane of glass or a full bed takes more or less the same
time. So, your line capacity is largely dependent on how efficiently you are
able to utilize the loading bed for each batch. Also, the more you are able
to load in a single loading, the more energy efficient your process will be
per square meter produced.

In a laminating line though, the term “loading efficiency” is a bit different,

as each glass pane can be considered as a separate batch.

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Consequently, there are two main ways to increase the amount of glass
that goes through your line:

1 Make sure that the gap between your glasses is as

small as possible

2 Run as much glass that can fit on your line

The main thing to keep in mind when considering your loading

efficiency is how big the gap is between your glasses. The smaller the
gap, the better the loading efficiency. The way the operators load glass
onto the line and their glass assembly can have a large effect on the
overall loading efficiency achieved.

Loading efficiency of 90–100%

Loading efficiency of about 65%

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If you are able to optimize the gap, you are optimizing the efficiency of
your line for your production mix. If you run larger glasses, your overall
throughput in square meters will increase, but that might not always be
what you are looking for.

Also note in a laminating line that, the effect of glass size on energy
consumption per square meter produced is very minor.

4.5 Costs
The actual cost of the laminating line can be estimated by dividing all
costs involved into three main categories:

1 Laminating line investment cost

2 Infrastructure costs

3 Operating costs

Apart from the laminating line itself, you need to consider how much
you need to invest in the infrastructure around the line, as well as what
will be the cost of operating the line.

Infrastructure costs
Infrastructure costs consist mainly of the cost of building a cleanroom
and purchasing an autoclave. Both of these are essential in order to run
a laminating line.

Cleanroom
Every laminating line needs a cleanroom to ensure that there are no
unwanted particles inside the laminate, as well as to provide good
conditions for the laminating foils.

Most often, the most cost-efficient solution is to build a cleanroom

locally by using local contractors.

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Building a cleanroom is not as simple as building walls around the line
and installing air conditioning.

The cleanroom is indeed a part of the laminating line,

ensuring smooth operation when loading the foils and making the
operators’ work as straightforward as possible.

Consult with your laminating line supplier to make sure that your
final cleanroom layout is as efficient as possible. Things to take into
consideration include, for example, ease of moving around the line,
automated and offline storage of the PVB rolls and sufficient lighting,
especially in the assembly area.

Below is a checklist of the most important information that your

cleanroom supplier will need from you. Make sure to request this
information from your laminating line supplier.

Cleanroom checklist

ITEM THINGS TO TAKE INTO ACCOUNT

Line layout indicating cleanroom dimensions How much space needs to be reserved
and construction around the line for easy operation? Should
there be a second floor for foil storage?
Weight distribution information How much weight will be placed on the
second floor (PVB rolls and other)?
Glass lifter installation method Is the glass lifter installed on the
cleanroom roof or floor?
Maximum temperature and humidity level in What kind of foils will you store, since
the cleanroom interleaved and refrigerated films have
separate requirements?
Thermal load inside the cleanroom How much heat is expected to be released
in the cleanroom from the motors and
other units that needs to be taken into
account for the air conditioning?
Air filtration requirements What kind of air filtration is recommended?
Cleanroom pressurizing Slight overpressurizing is recommended
to avoid uncontrolled air flows from the
factory hall into the cleanroom.
Cleanroom materials What kind of materials are recommended
to be used to avoid air contamination?
Local regulations for cleanrooms Your cleanroom supplier will be the best
expert to consult you on local regulations,
such as air circulation requirements.

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As a guideline, when processing an interleaved film, cleanroom and foil
storage can be done in the same physical space, which is also often the
most cost-efficient solution.

Every cleanroom will also require temperature control, humidity

control and dust filtration. Normally, the temperature needs to be
between 18–22 °C, and humidity should be around 25% maximum.

Note that the cleanroom requirements in a glass lamination business

are not as strict as in many other applications, such as in medical
laboratories, for example. So when considering dust and particle
filtering, this should also be taken into account.

Moreover, air circulation requirements must be followed according to

the local regulations.

Autoclave
The final quality of a laminate happens in the autoclave.
Efficient pre-pressing is a requirement for
good quality – but quality can still be ruined in
a bad autoclave cycle. The most important
factors in the autoclave are
The most important factors in the autoclave
are safety, as well as heating and cooling
safety, heating & cooling
technology. With renowned manufacturers, technology.
safety is guaranteed when international
standards are followed. Therefore, make sure
that your autoclave comes with all the required certificates.

When it comes to final product quality, heating and cooling technology

is extremely important.

Make sure that your autoclave has the capability to efficiently move
air inside the chamber to ensure that glasses and foils are sufficiently
heated.

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In addition, make sure that the heating and cooling capacity matches
your production needs. If
not, the technology can be
upgraded easily. If your laminating line’s heating and
cooling capacity does not match your
The worst mistake is to
buy an autoclave with production needs, the technology can be
insufficient heating and upgraded easily.
cooling capacity. This will
either reduce your overall
production capacity or result in poor end-product quality.

In the past, the autoclave systems required a separate rail system

for loading and unloading glasses. This needed to be integrated on
the factory floor. Also, making a special pit for the autoclave was a
prerequisite.

With modern autoclaves, these are no longer necessary. Now, the

process of loading and unloading glass can be done with movable racks
that include a rail system.

Make sure to check from your laminating line supplier what kind of
system the autoclave uses. Note that building a rail system and making a
pit can be costly.

To operate an autoclave, you need at least:

■■ Trolley and a rack system

■■ Air tank(s)
■■ Compressor
■■ Cooling tower

Make sure to find out which components are included in the autoclave
you are acquiring and which ones you need to purchase separately.

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Some components, such as compressors, are cheapest when
purchased locally. Make sure to consult with your autoclave
manufacturer about the technical requirements for such parts.

Operating costs
The cost of operating a laminating line can vary greatly. Pay attention to
the costs that relate to the particular technology you want to invest in.

The costs can be divided into running costs and maintenance costs.
The running costs include energy, waste and machine downtime.

When it comes to maintenance costs, note the difference between

heating technologies. For example, with an infrared laminating
furnace, the largest cost normally occurs from replacing the infrared
lamps. With a convection furnace, the maintenance costs are
significantly lower, as heater lifetime is much longer.

Running costs

The laminating line running cost is a sum of how much energy your line
uses, how much waste and poor-quality products are produced and the
cost of all possible downtime. The later implies product changes and
production losses. Depending on the line, there are big differences in
these costs.

Yield is definitely the most important criteria when it comes to selecting

a laminating line. If you can ensure a higher yield with a technology
that costs a bit more to acquire, the investment will still most certainly
have a very quick payback time. This is because every time things go
wrong, you end up wasting all the materials and time that went into
manufacturing the laminate. These can quickly add up to tens
of thousands of euros monthly.

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The main downside of running a line with an infrared heater is that
product changes normally require a lot of adjustments to the process.
This leads to the decreased yield, especially right after the production
change. Every product change also requires time, which means a loss
of production capacity.

With a convection line, the production is stable and predictable, no

matter how many product changes you make, thus resulting in a higher
yield.

Another aspect to consider is energy consumption. The main question

is what portion of all energy used is going into heating the glass and
how much is going to waste. There are considerable differences when
comparing infrared and convection technologies in this respect, as
well. With infrared heating technology, a large portion of heat must
be vented out of the furnace to prevent overheating, whereas with
convection technology, most of the energy
used is going solely to heat the laminates.
The heaters in a
Maintenance costs convection furnace can
last for decades and are
It goes without saying that regular
maintenance is needed to keep your line much cheaper compared
running smoothly for years to come. The to infrared lamps.
basic maintenance of the conveyors, lifters
and other parts is a small cost, as long as
the maintenance is performed according to instructions.

Traditionally, the largest maintenance cost in a laminating line comes

from having to frequently change infrared heaters in the furnace. This
can be a major annual cost and should be carefully considered with
lines equipped with an infrared heater.

A convection furnace offers a much more robust and low-maintenance

solution. The heaters in a convection furnace can last for years or even
decades and are also much cheaper compared to infrared lamps.
This means that the convection furnace provides less maintenance
and higher uptime in day-to-day production compared to an infrared
furnace.

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 5
Choose a laminating line
that suits your production
needs
What’s most important for you in a laminating line completely depends
on what kind of production you are going to be making. Production
types can be roughly divided into mixed laminating and stock sheet
laminating. Both alternatives and their effect on choosing a laminating
line type are described below.

5.1 Mixed production

The most typical case for a laminated glass manufacturer is mixed
production. This means producing a wide variety of different kinds of
glasses for different applications, such as façades and interior glass.
Order sizes are often small or medium, and production varies a lot, even
from hour to hour. The variety of glass sizes, shapes and interlayers
(types, colors and so on) is typically large. Competitive advantage is
largely based on the capability to produce customer orders quickly with
high yield.

It goes without saying that the ability to adapt to any kind of production
quickly is the most important thing for mixed production. The most
important factor affecting the laminating line output is the flexibility of
operations – those of your operators, as well as being able to switch
between different kinds of products with no or minimal changeover time.

A wide variety of products also poses a special challenge for your

heating and pre-pressing technology. The variety of glass types –
whether it is clear, Low-E, painted, partially painted or any other – is
high, and your furnace needs to be able to handle quick product
changes of small production batches without hiccups.

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Traditionally, product changes also involve a long changeover time
to adjust furnace temperature and other settings. A modern full
convection furnace provides the best flexibility and heating accuracy
for mixed production since the furnace reacts the same to different
glass types. This also means that there is no changeover time from one
glass type to another.

A full convection furnace also helps you keep your yield up, as furnace
temperature is always stable and does not need to be changed to
match the glass type.

Apart from the furnace, there are a lot of other decisions that can be
made in the laminating room to support efficient mixed production.
The largest factor to help your operators work more efficiently is the
trimming station. Using a narrow trimming station with easy access
to trim the glasses allows your operators to work on both sides of the
table.

A narrow trimming table also means that small glasses can be

processed by lifting the glasses manually, helping to achieve higher
output even with small glass sizes.

Make sure to choose enough motorized PVB magazines to smoothly

transition between different foils when needed.

For mixed production, a modern full convection furnace

provides the best flexibility and heating accuracy since
the furnace reacts the same to different glass types. This
also means that there is no changeover time from one
glass type to another.

Traditionally, laminating lines are equipped with rather wide trimming

conveyors. This leads to a situation where operators cannot reach the
glass to trim it from both sides at the same time.

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Consequently, trimming is done only from one side, and the operator
always needs to rotate the glass on the conveyor to be able to trim all the
edges. This results in a significantly lowered capacity because trimming
takes much more time than necessary.

To compensate for this, some manufacturers promote the possibility

to run two glasses side by side to enable higher capacity. While this
certainly increases capacity, two operators should trim glasses from
each side individually.

Most importantly, even in the best-case scenario, this kind of solution

still provides only a similar capacity as when using a narrow conveyor
where cycle time per glass is much lower.

Also, when considering running two glasses side by side, remember that
this normally means doing everything manually. Glass positioning and
lifting will not be automatic as it is when running just one glass at a time.
So, in reality, this is only convenient with very small glasses that a single
operator can lift easily.

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5.2 Stock sheet laminating
Stock sheet laminating means producing laminated jumbo glasses with
high capacity. Stock sheet laminates are typically float glasses (clear or
Low-E) that are sold to glass processors to be cut-to-size for smaller
customer orders. Batch sizes are typically large, and product changes
do not occur often in normal production. Competitive advantage is
based on production amounts with minimized costs.

The downside of stock sheet laminating is that tempered glass cannot

be used, since it cannot be cut afterwards.

Naturally, the main requirements for a stock sheet laminating line

are also different from mixed production. Even though an emphasis
on quick product changes is much smaller in this case, being able
to quickly change from product to product still remains a certain
advantage. Still, the focus here is more on being able to run large
batches as automatically as possible with a high yield. For the line, this
means features like automatic glass positioning, foil placement and
trimming.

A full convection furnace helps hugely by stabilizing the production,

minimizing product change times and increasing the line yield.

Optimizing cleanroom operations for a stock sheet laminating line is

much more about automating the line than making the process easy for
manual operations. This means that requirements, such as easy access
using a narrow trimming conveyor, do not apply so much to a stock sheet
line.

Automating the foil placement and trimming processes is also much

easier when the glass size is always constant. This is an important factor
to take into account when considering the requirements for a mixed
production or a stock sheet laminating line.

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5.3 A new line or modernization?
If you already have a laminating line, the first question to consider is
should you purchase a completely new line or modernize an existing
one.

Usually, modernizing a laminating line means the heating chamber and

the nip roll are upgraded to newer versions.

The upside of the modernization process is that costs are significantly

lower than buying a completely new line, since other parts of the old
line can still be utilized.

When deciding between a new line or a furnace modernization, it is

necessary to understand what is the reason for the investment in the
first place. Usually, it comes down to a lack of sufficient capacity or
quality issues.

Below is a table that presents the main factors to take into account
when considering purchasing a new line or modernizing an existing
one.

FACTOR ISSUE RECOMMENDATION

The furnace is the bottleneck, Furnace modernization or adding

cleanroom operations are more furnaces
always waiting for the furnace
Low-E glass cannot be run Consider upgrading to a full
Line capacity is not fast enough convection furnace
sufficient enough Changeover times between Consider upgrading to a full
products are too long convection furnace
Cleanroom operations cannot Most likely, a new line is needed
feed the furnace fast enough
Especially Low-E and painted Consider upgrading to a full
glasses result in a low yield convection furnace

Quality issues and low There are lots of bubbles in Fine-tune furnace recipes and the
yield the glasses pressing. Most likely, upgrading to
a full convection furnace can help
solve the issues

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 6
Typical pitfalls
Pitfall 1 : Wrong line size
This may seem like an obvious one, however, it is actually a tricky
point. The major issue is that if you don’t make your estimation on
future demand, you can end up with equipment that cannot handle the
required glass sizes or is taking too much floor space without having
the glasses to utilize the line’s full potential. A longer line always
means longer glass travel distances, which can affect capacity.

The line size you choose also has to be in line with the pre-processing
equipment you have available at your factory: if you wish to start
processing larger glasses, make sure to take this into account with
your other investments, such as cutting, grinding and tempering. Also
changing the line size in the future will basically mean purchasing a
new line. So if you are planning to upgrade other equipment in the near
future, it might make sense to take this into account already in the
purchasing phase.

When it comes to laminating lines, choosing too big of a line is not as

serious an issue as in tempering, since the effect of size on energy
consumption is much smaller in lamination. How big the effect is
depends a lot on the furnace technology you choose. With a full
convection line, the effect is going to be much smaller than with a line
equipped with an infrared heater.

Pitfall 2 : Business case and

production planning based on
theoretical values
Most often, the real capacity of your production will be lower than the
theoretical specifications – especially if you don’t do your homework.

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Many manufacturers give information about capacity in terms of line
speed, for instance, 4.2 m/min for 6/6/1 clear glass laminates.

However, with infrared heated lines, the furnace temperature and line
speed will typically be different depending on coatings and thicknesses!

At the same time, these lines also require changing the furnace
temperature and heat stabilization
time between product changes!
This means that the changeover Always demand to see continuous
and stabilization time will not be
productive time. The real production
mixed production in a real
output you get in a mixed production environment to fully understand
environment will be drastically what kind of capacity to expect from
different from what the furnace the line.
specifications might lead you to
believe.

Always demand to see continuous mixed production in a real

environment to fully understand what kind of capacity to expect.

There are also other reasons that can lead to the production not
meeting the theoretical values. For example:

■■ Complex user interface of the line

■■ Poorly trained operators
■■ Inefficient loading / assembly / trimming operations

Pitfall 3 : Investing in the

cheapest machine with the “same
specifications”
Laminating lines can be difficult to compare on papers. Pure number-
to-number comparisons can lead to the wrong conclusions. For
example, if you compare the line speeds of different manufacturers and
their prices, you will often end up making the wrong decision.

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Make a pricing calculation for your products. How big of a role does
the machine price play? Usually, it is fairly low. If this ends up being a
very minor difference, would you rather secure your quality, yield and
deliveries – or get the lowest investment price?

In reality, a well-designed line along with heating and pre-pressing

systems will enable a much higher output and success rate compared
to other alternatives.

Go beyond the basic figures. Demand to see figures that are all valid at
the same time. More importantly, go and see for yourself. Make a rough
plan based on specifications. Then put your full trust in the references!

Pitfall 4 : Lack of quality control

We are no longer living in the days when you could practically sell
everything that is produced by the machine. The market has become
extremely quality conscious nowadays, and you need to have your own
quality control.

Take into account that some issues with laminated glasses might only
be seen years after usage. And at that point, fixing the issues will be
very expensive.

Pitfall 5 : Not considering line yield

in investment calculations
The capacity of the line is often the main figure being analyzed when
making an investment. While capacity is an important factor, it means
nothing if delays in production and yield are not considered.

The overall yield will have a huge impact on the profitability of your
operations. Especially in lamination, where a huge amount of value is
added to the glass before the actual laminating process is even started.
And once the process is complete, there is no way to redo it – you will
have to process everything again from scratch.

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For example, if you end up wasting 5% of your production by making
poor-quality products, you will have severe difficulties in reaching your
payback – no matter how cheap the initial investment was. Moreover,
in lamination, the cost of bad quality can be so high that investing a bit
more in better quality equipment will pay itself back very quickly.

Pitfall 6 : Related processes not in

shape
A key factor in succeeding in lamination is ensuring that all processes
related to lamination are in good shape. The most critical ones are
tempering and autoclaving.

Tempering

Often, certain issues in lamination can be traced back to bad tempering

quality. What matters for the process is the gap between the glass
panes and foil(s). This means how well the glass panes match together
can have a bigger effect on the outcome than roller wave and edge lift
values from the tempered glass.

Good tempering operations and procedures in matching glasses will

make lamination much easier. A good rule of thumb is that if you are
facing issues with some laminated glasses – and no problems when
ordinary flat glass is used – the root cause can most likely be traced
back to tempering.

Autoclaving

Autoclaving is the final phase of the laminating process. While the

autoclave cannot make bad-quality pre-laminates better, it can have a
significant effect on the actual yield of your production.

Most importantly, bad autoclaving can completely ruin even the best-
quality pre-laminates. It might be tempting to rely on an old, used or
otherwise cheap autoclave, but make sure to acknowledge the most
important things in the autoclave process.

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In an autoclave, the most important things are sufficient heating and
cooling power as well as the software control of heating and cooling
ramps. If your autoclave cycle is not able to follow the interleaf
manufacturer’s instructions about the ramps, it is going to be very
difficult to achieve good quality
consistently.
In an autoclave, the most important
If you have any doubts, make things are sufficient heating and
sure to measure the actual
cooling power as well as the software
glass temperatures during the
process from the middle of control of heating and cooling ramps.
the glass panes. This can help
verify if autoclaving is causing
any quality issues.

Also, make sure to consider that different interleaves require different

settings: applying SentryGlas® or EVA with a standard PVB recipe will
not yield good results.

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 7
Assessing and choosing
your partner –
The good quality
dilemma
If you ask any manufacturing company today, they will all say that they
have good quality products. Most likely, they also claim to be flexible,
efficient and reliable. Since each supplier makes the same promises,
these words have lost their meaning. Since you want to work with
a high-quality partner who makes high-quality products, you will
need to dig deeper.

Quality can mean different things to different people:

■■ Quality of the product and its appropriateness for the use
■■ Meeting and exceeding customer expectations
■■ Superiority over the competition

Quality can refer to a specific product or to a way of working. In the

purchasing phase, it can be difficult to judge if the actual product really
produces a quality end result. There are, of course, methods like looking
at the welding quality, consistency, components quality and other details.
However, no product will offer good quality unless the ways of working to
manufacture the product are world-class. This covers everything from
product development to the service processes.

Quality covers the full capability

of everything – from product
development to the service
processes for the machine.

52 ©Glaston Corporation 2020

Getting over the good quality dilemma requires you to ask questions
that dig deep into a suppliers’ operations. Don’t settle for certificates:
quality is much more than ISO 9001.
Concentrate on how the supplier really
works. Quality is much more
than ISO 9001!
The best source for getting an actual
quality reference is to ask questions
from the persons who have used the product you are considering. It is
usually very easy to arrange a 15-minute phone interview with an existing
user. You can go even further and call a few of their key customers to find
out what they really think about the glass quality produced. Interviewing
an existing user will give you valuable information about the laminating
line performance.

It is usually very easy to arrange a 15-minute

phone interview with an existing user of the
furnace you are considering.

Here are some questions for

current laminating line users:

■■ Did the performance meet your expectations and

requirements? Is the performance in line with the
specifications given?
■■ How is the serviceability of the line? What does your
maintenance program look like?
■■ How about reliability and durability? What is the uptime of
the machine? How often do you need to change components?
■■ Ease of use: can all of your operators use the line in the same
way? How long does it take to train a new operator to use it?
■■ What is your experience with the service response time?
How about with spare parts?

53 ©Glaston Corporation 2020

If you want to find out more about the actual quality of a supplier’s way
of working and overall capabilities, here are some questions that will
either uncover some of the supplier’s weaknesses or further validate the
evidence of quality work:

■■ How do you follow the market trends and how do you make
sure your product development results in innovations that the
market needs?
■■ How do you gather and measure customer feedback?
■■ What kind of development programs have you run in your
production facilities during the last two years?
■■ What KPIs do you have for your production and your
company?
■■ How have you been able to decrease your delivery times
during the past few years?
■■ How do you measure your quality costs and how have you
been able to minimize them?

These questions can throw curveballs to companies that are not truly
focused on their customers and quality. The answers will give you a
deeper understanding of the quality of the supplier and its products.

Things to consider in the purchasing phase:

■■ Solve the good quality dilemma by digging deeper.
■■ Request reference contacts and visits.
■■ To get a better understanding, go to the reference company’s
customers for feedback.

54 ©Glaston Corporation 2020

 Your checklist before
the purchasing phase:

Go beyond the good quality dilemma. Ask and see for

yourself.

Use the questions from this chapter or create your

own list that helps you get a true understanding of a
supplier’s capabilities.

Go and see for yourself. Reference visits are golden

opportunities.

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 8
Your checklist for
a profitable investment
We compiled this checklist for you as a helpful reminder of what
to look for when considering a laminating line investment. Asking the
right questions will take you closer to a profitable investment. Even if you
have already done your homework, sometimes a summary, like the one
below, can help you focus your thoughts for a better decision-making
process.

LAMINATING LINE BUYER’S CHECKLIST

CRITERIA MANUFACTURER X MANUFACTURER Y

SCORE / SOLUTION SCORE / SOLUTION

General
Industry experience
R&D backup
Company risk
Technology risk
Innovation ability
Production facilities and
construction quality
Health and safety issues
Availability of support and service
Process consultation ability
Spare parts availability
Local support availability
Experience with the manufacturer
Future upgrading possibility
Machinery lifetime, total
investment costs over 15 years
Company financial numbers

Commercial / project-specific terms

Price
Delivery time
Installation time
Shipping time

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 Project management
Ability to consult during the project
Payment terms
Financing possibility

Production issues
Float glass production m /shift
2

Soft coat Low-E glass production

m2/shift
Possible delays in
continuous production
Energy efficiency
Ability to process
different glass types
Line upgrade possibilities, for
example, 2–3 mm glass or
extra capacity
Training (onsite and offsite)
Machine uptime (yield)
Recovery time from faults

Loading table
Lifting table(s)
Tilting table(s)
Is a sink included to prevent the
washing machine from dripping on
the floor?

Washing machine
Ease of use
Automatic thickness measurement
and adjustment
Is there a requirement to adjust
brushes based on glass type?

Assembly and trimming

Ease of use: is the glass run in
the middle or on the edge of the
conveyor?
Width of the assembly and
trimming conveyor
How are wide glasses supported?

Glass lifter
Glass lifter construction: how
convenient is it to work around the
glass lifter?
Does the lifter construction block
manual operation?
What is the lifting technology used?
Do suction cups leave marks on
the glass?

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 Automated PVB magazines
What is the number of automated
PVB magazines?
How are they controlled?
Is there an automated PVB cutter
included?
How does the PVB cutter’s
functionality change over time?
Can the correct PVB length be
automatically selected according to
measurement?
How is PVB information handled
and stored in the system?

Heating section / nip roll

Technology:
convection or infrared heaters
Glass exit temperature
measurement:
pyrometer or scanner
Changeover time between the
products
Pressing technology:
uniformity, ease of operation
Serviceability of the heating
chambers
Estimated maintenance costs

Control system
Remote diagnostics
Extensive reporting features:
cloud-based production reporting
Ease of recipe adjustment
Integration with other systems
Ease of use

Health & safety

CE or similar conformity
CE or similar mark received
Safety guards / areas

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Be proud of your decision
We have presented a number of points and tools in this guidebook to
help you in your buying process. We hope you find them valuable. We are
happy to help you in selecting the most suitable line – a line that will fit
your production needs – a line you can be proud of.

In the end, maybe the most important factor when selecting a partner is
to choose one that you love to work with. This is a partner that you trust,
feel comfortable with and who can consult and support you, not only
today, but throughout your entire business journey. A package that you
can be proud of. After all, this might be the biggest investment in your
business.

We hope you have enjoyed this and can put the value of this information to
use for real.

Riku Färm Jussi Niemioja Tuomo Nuottimäki

Product Manager Senior Research and Area Sales Manager
Innovations Manager

59 ©Glaston Corporation 2020

The Laminating Line
BUYER´S GUIDE