TECHNICAL DATA SHEET
GRILAMID TR 90
Product description
Grilamid TR grades are transparent thermo-
plastic polyamides based on aliphatic and
cycloaliphatic blocks. Grilamid TR 90 offers a
variety of interesting properties such as:
· clear transparency even in high wall
thicknesses
· good light natural colour
· can be coloured in transparent as well as
opaque colours
· tough
· stiff
· good chemical- and stress-crack resis-
tance
· high flexural fatigue strength
Grilamid TR grades are suitable for produc-
tion of optical and technical demanding parts
in the application fields of:
- Optics
- Electro
- Electronics
- Automotive
- Mechanical engineering
- Domestic appliances
PROPERTIES
Mechanical Properties
Standard Unit State Grilamid TR 90
Tensile E-Modulus 1 mm/min ISO 527 MPa cond. 1600
Tensile strength at yield 50 mm/min ISO 527 MPa cond. 60
Elongation at yield 50 mm/min ISO 527 % cond. 6
Tensile strength at break 50 mm/min ISO 527 MPa cond. 45
Elongation at break 50 mm/min ISO 527 % cond. > 50
Impact strength Charpy, 23°C ISO 179/2-1eU kJ/m² cond. no break
Impact strength Charpy, -30°C ISO 179/2-1eU kJ/m² cond. no break
Notched impact strength Charpy, 23°C ISO 179/2-1eA kJ/m² cond. 13
Notched impact strength Charpy, -30°C ISO 179/2-1eA kJ/m² cond. 12
Ball indentation hardness ISO 2039-1 MPa cond. 90
Thermal Properties
Glass transition temperature DSC ISO 11357 °C dry 155
Heat deflection temperature HDT/A 1.80 MPa ISO 75 °C dry 115
Heat deflection temperature HDT/B 0.45 MPa ISO 75 °C dry 135
-4
Thermal expansion coefficient long. 23-55°C ISO 11359 10 /K dry 0.9
-4
Thermal expansion coefficient trans. 23-55°C ISO 11359 10 /K dry 0.9
Maximum usage temperature long term ISO 2578 °C dry 80 - 100
Maximum usage temperature short term ISO 2578 °C dry 120
Electrical Properties
Dielectric strength IEC 60243-1 kV/mm cond. 34
Comparative tracking index CTI IEC 60112 - cond. 600
11
Specific volume resistivity IEC 60093 W·m cond. 10
12
Specific surface resistivity IEC 60093 W cond. 10
General Properties
Density ISO 1183 g/cm³ dry 1.00
Flammability (UL94) 0.8 mm ISO 1210 rating - HB
Water absorption 23°C/sat. ISO 62 % - 3
Moisture absorption 23°C/50% r.h. ISO 62 % - 1.5
Linear mould shrinkage long. ISO 294 % dry 0.65
Linear mould shrinkage trans. ISO 294 % dry 0.75
Product-nomenclature acc. ISO 1874: PA MACM12, GT,14-020
2
Processing information for the injection moulding of Grilamid TR 90
This technical data sheet for Grilamid TR 90 pro- Silver streaks can also be caused by
vides you with useful information on material prepa-
ration, machine requirements, tooling and process-
! overheating of the material (over 320°C)
or by too long melt residence time in the
ing. barrel.
Drying temperature
MATERIAL PREPARATION Polyamides are subjected to the affects of oxidation
at temperatures above 80°C in the presence of
Grilamid TR 90 is delivered dry and ready for proc- oxygen. Visible yellowing of the material is an indi-
essing in sealed, air tight packaging. Predrying is cation of oxidation. Hence temperatures above
not necessary. 80°C for desiccant dryers and temperatures above
100°C for vacuum ovens should be avoided. In
order to detect oxidation it is advised to keep a
Storage
small amount of granulate (light colour only !) as a
Amorphous polyamides can be stored over years
comparison sample.
without negatively influencing it’s mechanical prop-
erties. However, in order to ensure optimal colour
At longer residence times (over 1 hour) hopper
and transparency, Grilamid should not be stored for
heating or a hopper dryer (80°C) is useful.
more then 6 months. At temperatures above 25°C
in combination with long storage temperatures, the
oxidation saturation process of the granulate is Use of regrind
accelerated. Hence, it is advised to keep storage Grilamid TR 90 is a thermoplastic material. Hence,
temperatures below 25°C. The above mentioned incomplete mouldings as well as sprues and run-
effect becomes only visible after injection moulding ners can be reprocessed. The following points
and shows itself in parts which have a more yellow should be observed:
appearance. Storage facilities must be dry and
protect the bags from the influence of weather and · Moisture absorption
damage. · Grinding: Dust particles and particle size distri-
bution
Handling and safety · Contamination through foreign material, dust,
Detailed information can be obtained from the oil, etc.
“Material Safety Data Sheet” (MSDS) which can be · Quantity addition to original material
requested with every material order. · Colour variation
· Reduction of mechanical properties
Drying
Grilamid TR 90 is dried and packed with a moisture When adding regrind, special care has to be taken
content of less than 0.08 %. Should the packaging by the moulder.
become damaged or the material is left open too
long, then the material must be dried. A too high
moisture content can be shown by a foaming melt MACHINE REQUIREMENTS
and silver streaks on the moulded part when in-
jected freely into the atmosphere (free shot). Grilamid TR 90 can be processed economically and
problem-free on all machines suitable for polyam-
Drying can be done as follows: ides.
Desiccant dryer Screw
Wear protected, universal screws with shut-off
Temperature: max. 80°C nozzles are recommended (3 zones).
Time: 4 - 6 hours
Dew point of the dryer: -30°C
Screw
Vacuum oven Length: 18 D - 22 D
Compression ratio: 2 - 2.5
Temperature: max. 80°C
Time: 4 - 8 hours Shot volume
The metering stroke must be longer than the length
Drying time of the back flow valve (without decompression
If there is only little evidence of foaming of the melt distance).
or just slight silver streaks on the part, then the
above mentioned minimal drying time will be suffi- Selecting the injection unit
cient. Material, which is stored open over days, Shot volume = 0.5 - 0.9 x
which shows strong foaming, unusually easy flow- (max. shot volume)
ing, streaks and rough surface on the moulding
part, then the maximal drying time is required.
3
Heating PROCESSING
At least three separately controllable heating
zones, able of reaching cylinder temperatures up to Mould filling, post pressure and dosing
350°C. A separate nozzle heating is necessary. The injection speed should be regulated so as to
The cylinder flange temperature must be controlla- reduce towards the end of the filling cycle in order
ble (cooling). to avoid burning. For dosing at low screw revolu-
tions and pressure the cooling time should be fully
Nozzle utilised.
Open nozzles are simple, allow an easy melt flow
and are long lasting. There is however the danger Basic machine settings
that during retraction of the screws following injec- In order to start up the machines for processing
tion of the melt, air maybe drawn into the barrel Grilamid TR 90, following basic settings are rec-
(decompression). For this reason, needle shut-off ommended:
nozzles are often used.
Temperatures
Clamping force Flange 40°C
As a rule of thumb the clamping force can be esti- Zone 1 255°C
mated using the following formula: Zone 2 260°C
Zone 3 265°C
Clamping force Nozzle 260°C
Tool 80°C
1)
7.5 kN x projected area (cm )
2 Melt 265°C
1)
in cavity pressure of 750 bar
Pressures / Speeds
TOOLING
Injection speed medium - high
The design of the mould tool should follow the
Hold-on pressure (spec.) 300 - 600 bar
general rules for transparent thermoplastics.
Dynamic pressure (hydr.) 5 - 10 bar
-1
Screw speed 50 - 100 min
For the mould cavities common mould tool steel
quality (e.g. hardened steel) which has been hard-
ened to level of 56 HRC is recommend.
CUSTOMER SERVICES
Gate and runner
To achieve an optimal mould-fill and to avoid sink EMS-GRIVORY is a specialist for polyamide syn-
marks, a central gate at the thickest section of the thesis and polyamide-processing. Our customer
moulding is recommended. Pin point gate (direct) or services are not only concerned with the manufac-
tunnel gates are more economical and more com- turing and supply of engineering thermoplastics but
mon with technical moulding. also provide a full of technical support program:
To avoid premature solidification of the melt and · Rheological design calculation / FEA
difficult mould filing, the following points should be · Prototype tooling
considered: · Material selection
· Processing support
Gate diameter · Mould and component design
0.8 x thickest wall section of the injection We are happy to advice you. Simply call one of our
moulding part sales offices.
Runner diameter
1.4 x thickest wall section of the injection
moulding part (but minimum 4 mm)
The recommendations and data given are based on our
VENTING experience to date, however, no liability can be assumed
In order to prevent burning marks and improve in connection with their usage and processing.
weldline strength, proper venting of the mould cav-
ity should be provided (venting channels on the LHT/04.2001
parting surface dimensions: Depth 0.02 mm, width www.emsgrivory.com
2 - 5 mm).
