Injection Moulding
In the injection moulding process TPE pellets are fed into the machine through a hopper and then into a heated barrel. The heat from the barrel turns the material into a liquid resin which is then injected into a closed mould under high pressure. After allowing the molten polymer to cool, the finished part can be removed from the mould.
Injection moulding is a high-volume, high tooling cost process, the advanced properties of our TPE compounds deliver short cycle times allowing parts to be produced at a rapid rate.
The information below is intended as a general overview, settings may vary depending on the specific grade selected. Please contact us for detailed processing information
Settings
Equipment | Conventional injection moulding machine |
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Compression set | At least 2:1. Special screws with short sections and higher compression ratios (3:1 to 4:1) may be good at low screw speeds |
Shrinkage | Between 1.0% and 2.5% depending on the grade, type of application and location of the gate
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Mould surface | Produced by EDM or shot blasted is recommended |
Ejection | Ejector plates are generally recommended for soft grades. If ejector pins are used, they should be as large as possible and act on sections of the part that are stiffest |
Gates | Diaphragm gate, fan gate, submarine gate, multiple-pinpoint gate |
Venting | A vent groove depth of 0.01 to 0.02 mm is generally sufficient |
SEBS based materials
Runner temperature | Depending on the grade of material, the lowest temperature of material in runner, during unloaded parts of cycle should be 170 – 240°C |
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Cylinder temperature | 190 – 245°C (260°C may be necessary for large parts) |
Mould temperature | 15 – 60°C |
Injection velocity | Due to the strong viscosity/shear rate relationship, a high injection velocity is desirable for SEBS based materials |
SBS based materials
Runner temperature | Depending on the grade of material, the lowest temperature of material in runner, during unloaded parts of cycle should be around 170 – 200°C |
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Cylinder temperature | 170 – 200°C, should not exceed 220°C |
Mould temperature | 15 – 60°C |
Injection velocity | SBS compounds should preferably be injected at moderate injection velocities |
Contact Our Experts
Drop an email to DEX and he’ll arrange for your local expert to contact you
DEX
Mr TPE
Processing guides
You can also visit our Downloads page for more brochures and information.
Lifocork Processing Guide
TPE Chemical Resistance
TPE Processing Guide
TPE Processing Guide – Adhesion
TPE Processing – Problem Solving
