Assignment No.

1
The economic growth of industrialized countries relies on the manufacturing
industry for finished products. The chemical industry is highly globalized and
produces thousands of chemicals from a wide variety of raw materials by
means of varied technologies for varied end uses. Therefore, describe the
manufacturing process of at least two industrial products being manufactured
in your locality.

Solution:
Paper and pulp industry:
Paper is a thin sheet material produced by mechanically or chemically
processing cellulose fibres derived from wood, rags, grasses or other vegetable
sources in water, draining the water through fine mesh leaving the fibre evenly
distributed on the surface, followed by pressing and drying.One of the producers of
papers and boards in Lahore is Al quresh board mills

Raw Materials

 Plant fibre
 Sulfite salts
 Sulfur dioxide
 Caustic soda
 Sodium sulfide

Procedure:

Pulping procedure will be done to separate and clean the fibers. Refining procedure
will be followed after pulping processes.Dilution process to form a thin fiber
mixture.Formation of fibers on a thin screened. Pressurization to enhance the
materials density.Drying to eliminate the density of materials.Finishing procedure
to provide a suitable surface for usage.Pulp and paper are made from cellulosic
fibers and other plant materials. Some  synthetic materials may be used to impart
special qualities to the finished product. Paper is made from wood fibers, but rags,
flax, cotton linters, and bagasse (sugar cane residues) are also used in some papers.
Used paper is also recycled, and after purifying and sometimes deinking, it is often
blended with virgin fibers and reformed again into paper. Products such as
cellulose acetate, rayon, cellulose esters that are made from cellulose will be used
for packaging films, explosives.

The pulping process is aimed at removing lignin without loosing fiber strength,
thereby freeing the fibers and removing impurities that cause discoloration and
possible future disintegration of the paper.

Hemicellulose plays an important role in fiber-to-fiber bonding in papermaking. It

is similar to cellulose in composition and function. Several extractives such as
waxes, oleoresins are contained in wood but they do not contribute to its strength
properties; these too are removed during the pulping process.

The fiber extracted from any plant can be used for paper. However, the strength
and quality of fiber, and other factors complicate the pulping process. In general,
the softwoods (e.g., pines, firs, and spruces) yield long and strong fibers that
contribute strength to paper and they are used for boxes and packaging.

Hardwoods produce a weaker paper as they contain shorter fibers. Softwoods are
smoother, transparent, and better suited for printing. Softwoods and hardwoods are
used for paper-making and are sometimes mixed to provide both strength and print
ability to the finished product.

Steps involved in the Pulp and Papermaking Procedure:

Preparation of raw Material

Wood that has been received at a pulp mill can be in different forms. It depends on
the pulping process and the origin of the raw material. It may be received as bolts
(short logs) of round-wood with the bark still attached, as chips about the size of a
half-dollar that may have been produced from sawmill from debarked round wood
elsewhere.

If round wood is used, it is first debarked, usually by tumbling in large steel drums
where wash water may be applied. Those debarked wood bolts are then chipped in
a chipper if the pulping process calls for chemical digestion. Chips are then
screened for size, cleaned, and temporarily stored for further processing.

Separation of Fiber

In the fiber separation stage, several pulping technologies will be diverged. The
chips are kept into a large pressure cooker (digester), into which is added the
appropriate chemicals in kraft chemical pulping.

The chips are then digested with steam at specific temperatures to separate the
fibers and partially dissolve the lignin and other extractives. Some digesters
operate continuously with a constant feed of chips (furnish) and liquor are charged
intermittently and treat a batch at a time.

After the digestion process, the cooked pulp is discharged into a pressure vessel.
Here the steam and volatile materials are tubed off. After that, this cooked pulp is
returned to the chemical recovery cycle.  Fiber separation in mechanical pulping is
less dramatic.

Debarked logs are forced against rotating stone grinding wheels in the stone
ground-wood procedure. Refiner pulp and thermo-mechanical pulp are produced
by chips. These chips are ground by passing them through rapidly rotating in both
processes.

In the second stage after refining, the pulp is screened, cleaned, and most of the
process water is removed in preparation for paper making.

Bleaching Process

Raw pulp contains an appreciable amount of lignin and other discoloration, it must
be bleached to produce light colored or white papers preferred for many products.
The fibers are further delignified by solubilizing additional lignin from the
cellulose through chlorination and oxidation. These include chlorine dioxide,
chlorine gas, sodium hypochlorite, hydrogen perioxide, and oxygen.

Sodium Hydroxide, a strong alkali is used to extract the dissolved lignin from
fibers surface. The bleaching agents and the sequence in which they are used
depend on a number of factors, such as the relative cost of the bleaching chemicals,
type and condition of the pulp.
Mechanical pulp bleaching varies from chemical pulp bleaching. Bleaching of
mechanical pulp is designed to minimize the removal of the lignin that would
reduce fiber yields.

Chemicals used for bleaching mechanical pulps selectively destroy coloring

impurities but leave the lignin and cellulosic materials intact, These include
sodium bisulfite, sodium or zinc hydrosulfite (no longer used in the United States),
calcium or sodium hypochlorite, hydrogen or sodium peroxide, and the Sulfur
Dioxide-Borol Process (a variation of the sodium hydrosulfite method).

Papermaking Procedure

Bleached or unbleached pulp may be further refined to cut the fibers and roughen
the surface of the fibers to enhance formation and bonding of the fibers as they
enter the paper machine.

Water is added to the pulp slurry to make a thin mixture normally containing less
than 1 percent fiber. The dilute slurry is then cleaned in cyclone cleaners and
screened in centrifugal screens before being fed into the ‘wet end’ of the paper-
forming machine. The dilute stock passes through a head-box that distributes the
fiber slurry uniformly over the width of the paper sheet to be formed.
Detergent industry:

Powder detergent is used for removing stains, typically from various kinds of
fabric. It’s a popular and affordable option for cleaning fabrics, available in
recyclable, eco-friendly packages such as cardboard boxes.

The major manufacturer of detergent in Lahore is hidayat chemical industry in

quaid e azam industrial estate.

Raw materials:

 Sodium Tripolyphosphate (STPP)

 Linear Alkyl Benzene Sulphonic Acid (LABSA)

 Sodium Aluminosilicate (4A Zeolite)

 Sodium Sulphate Anhydrous (SSA)

 Sodium Carbonate Anhydrous (Soda ash light)

 Sodium Silicate (WATER GLASS)

 Sodium Metasilicate Pentahydrate

 Caustic Soda (Pearls & Flakes)

 Sodium Percarbonate

 Colorful Speckles

 Optical Brightening Agents

 Sodium Lauryl Ether Sulfate (SLES)

 Alpha Olefin Sulphonate (AOS)

 Fatty Alcohol Polyoxyethylene Ether (AEO-9)

 Cocamidopropyl Betaine (CAB)

 Coconut Diethanolamide (CDEA)

  Tetraacetylethylenediamine (TAED)

 Sodium Lauryl Sulfate(K12)

Manufacturing procedure:

1. Handling raw materials

Before anything, it’s necessary to handle raw materials properly, and that

includes storage and transport. There are two types of chemical ingredients used in
the production of powder detergent: liquid and solid.

Most solid ones come in powdered form, packed in woven bags, such as Soda
Ash or STPP, while liquids like LABSA or Caustic lye are commonly stored in
tanks.

2. Raw materials dosing

After the ingredients have been loaded in appropriate tankers, the automated
process starts with measuring and dosing. To ensure smooth and precise flow,
every step is monitored and controlled by an operator-surveyed PLC system.

All formulas and details are stored in the system memory and applied
automatically. An average manufacturer works with hundreds of formulas, from
their own branded products to specialized contract manufacturing recipes.

3. Preparation and aging of slurry 

After the ingredients have been dosed and delivered by pipes and conveyors, they
are mixed to form a base powder. First, the Crutcher stirs and mixes them with
processed water for up to one hour, on average.

The mixed slurry then goes to “age” for up to half an hour in the aging tank.

4. Spray drying phase

After aging, the pumps start to spray the mix up to the top of the spray drying
tower. The nozzles in the tower form atomized droplets, while the hot air furnace
produces hot air to dehydrate them further.
In the end, the spray-dried granules (particles) fall to the bottom of the tower where
they are collected and stored as a base powder.

The base powder is a semi-finished product that contains no enzymes,

fragrances, or colorful speckles. It can be further customized per need, delivered
for private labeling, or sold as bulk washing powder.

5. Filtration process

After all moisture has been evaporated, the hot air cools down and needs to be
discharged. The reason is that the exhausted air contains fine dust residue.

Also, the base powder needs filtering by a mesh – such as a vibrating screen – to
eliminate all oversized particles and scrapes.

6. Post-tower dosing and blending

The post-tower processing plant performs the fine-tuning of the base powder.

Additives such as enzymes, fragrances, colorful speckles, and all ingredients that
cannot pass through the spray drying process are added and blended with the
original mixture to form a customized product.

The finished powder then travels to the storage bins and packing machines for
final packing.

7. Packing & Labeling

In the final step, manual and automatic packing machines load the pouches,
buckets, and woven bags with washing powder detergent.

Block flow diagram: