11/04/2026
Process Parameters of Injection Molding:-
🔥 1. Melt Temperature (Plastic Heating) 🌡️
Plastic granules are heated until they become molten (liquid form).
Proper temperature ensures smooth flow.
✅ Example:
For Polypropylene, melt temperature is around 200–250°C.
⚠️ Too high → material burns 🔥
⚠️ Too low → incomplete filling ❌
⚡ 2. Injection Pressure (Force to Fill Mold) 💪
Pressure used to push molten plastic into the mold cavity.
✅ Example:
Making a plastic bottle cap requires high pressure to fill small details.
⚠️ Too high → flash (extra material) 🧈
⚠️ Too low → short shot (incomplete part) 🕳️
🚀 3. Injection Speed (Injection Rate) 🏎️
Speed at which molten plastic enters the mold.
✅ Example:
Thin products (like plastic containers) need high speed for proper filling.
⚠️ Too fast → air traps 💨
⚠️ Too slow → weld lines ⚡
🧱 4. Holding Pressure (Packing Phase) 🧲
Pressure applied after filling to pack material and avoid shrinkage.
✅ Example:
Used in thick parts like buckets to maintain shape.
⚠️ Low → sink marks 😓
⚠️ High → stress cracks ⚠️
⏱️ 5. Injection Time (Cycle Duration) ⏳
Time taken to inject molten plastic into mold.
✅ Example:
Small parts = short time
Large parts = longer time
❄️ 6. Cooling Time (Solidification) 🧊
Time required for plastic to cool and solidify inside mold.
✅ Example:
A thick plastic chair needs more cooling time than a thin spoon.
⚠️ Less time → deformation 🫠
⚠️ More time → slow production 🐢
🔒 7. Clamp Pressure (Mold Closing Force) 🛠️
Force used to keep mold tightly closed during injection.
✅ Example:
Large molds (like crates) require high clamp force.
⚠️ Low → mold opens → flash ⚠️
⚠️ High → machine damage
🎯 Real-Life Example (Complete Process)
👉 Making a plastic water bottle cap:
Plastic is melted 🔥
Injected with high pressure 💪
Packed to avoid shrinkage 🧱
Cooled to solidify ❄️
Mold opens & part ejects 🎉
🧠 Easy Trick to Remember 🪄
“T-P-S-H-T-C-C”
👉 Temperature → Pressure → Speed → Holding → Time → Cooling → Clamping
