2026 Latest Common Plastic Injection Molding Process Parameters
The following is a collation of molding process parameters for common plastics in the 2026 injection molding industry, covering two major categories: general-purpose plastics and engineering plastics, with a total of 12 common materials. The parameters apply to standard production scenarios for ordinary horizontal injection molding machines and conventional structure molds, serving as a basic reference for on-site machine adjustment and process setup. Differences in material grades, machine conditions, product structures, and modified additives (glass fiber, toughening agents, etc.) will affect molding conditions. In actual production, reasonable minor adjustments can be made within the ranges in this table to adapt to on-site production requirements.
| Material | Barrel Temp (℃) | Nozzle Temp (℃) | Mold Temp (℃) | Melt Temp (℃) | Injection Pressure (MPa) | Holding Pressure (MPa) | Back Pressure (MPa) | Screw Speed (rpm) | Drying Specification |
|---|---|---|---|---|---|---|---|---|---|
| PP | 180-220 200-240 210-250 | 210-240 | 30-60 | 200-240 | 80-120 | 30-60 | 0.3-0.8 | 50-150 | Generally unnecessary High precision: 80℃ 1-2h |
| LDPE | 150-180 160-200 170-210 | 170-200 | 20-40 | 160-190 | 60-100 | 20-50 | 0.2-0.5 | 60-200 | No drying required |
| HDPE | 180-200 200-230 210-240 | 210-230 | 40-60 | 200-230 | 80-140 Thin wall: up to 180 | 40-70 | 0.3-0.6 | 80-200 | ≤0.3% moisture: no need |
| ABS | 180-210 200-240 210-250 | 210-240 | 45-70 | 220-245 | 90-130 | 40-70 | 0.5-1.0 | 50-120 | 75-80℃ 2-4h Mandatory |
| PS | 170-190 180-220 190-230 | 190-220 | 30-50 | 190-230 | 70-110 | 30-50 | 0.3-0.8 | 60-180 | No drying required |
| PVC | 140-160 150-170 160-180 | 160-180 | 20-45 Rigid:30-50 | 160-190 | 80-120 | 40-60 | 0.2-0.5 | 20-60 | Generally unnecessary |
| PC | 250-270 270-290 280-300 | 280-300 | 70-95 High finish:90-120 | 280-305 | 100-160 | 50-80 | 0.8-1.5 | 40-100 | 100-120℃ 3-6h Moisture＜0.02% |
| PA6 | 220-240 230-260 240-270 | 240-260 | 60-90 | 240-270 | 90-140 | 40-70 | 0.5-1.0 | 50-120 | 80-90℃ 4-6h Moisture＜0.1% |
| PA66 | 230-250 240-270 250-280 | 250-270 | 70-100 | 250-280 | 100-150 | 50-80 | 0.8-1.2 | 40-100 | 85-95℃ 4-6h |
| POM | 160-180 170-200 180-210 | 180-200 | 50-70 | 190-210 | 80-120 | 40-60 | 0.3-0.8 | 60-150 | 80℃ 2-3h Optional |
| PBT | 220-240 230-250 240-260 | 240-260 | 50-80 | 250-265 | 100-140 | 50-80 | 0.5-1.0 | 50-120 | 120-130℃ 3-5h |
| PET | 250-270 260-280 270-290 | 270-285 | 80-120 | 270-290 | 120-180 | 60-100 | 0.8-1.5 | 60-150 | 130-140℃ 4-6h Deep drying required |
I. General-Purpose Plastics (PP/PE/ABS/PS/PVC)
1. PP (Polypropylene)
Barrel Temperature: 180–220°C (front section), 200–240°C (middle section), 210–250°C (rear section)
Nozzle Temperature: 210–240°C
Mold Temperature: 30–60°C
Melt Temperature: 200–240°C
Injection Pressure: 80–120 MPa
Holding Pressure: 30–60 MPa (30–50% of injection pressure)
Back Pressure: 0.3–0.8 MPa
Screw Speed: 50–150 rpm
Drying: Drying is generally unnecessary; for high-precision requirements, dry at 80°C for 1–2 hours
2. LDPE (Low-Density Polyethylene)
Barrel Temperature: 150–180°C, 160–200°C, 170–210°C
Nozzle Temperature: 170–200°C
Mold Temperature: 20–40°C
Melt Temperature: 160–190°C
Injection Pressure: 60–100 MPa
Holding Pressure: 20–50 MPa
Back Pressure: 0.2–0.5 MPa
Screw Speed: 60–200 rpm
Drying: No drying required
3. HDPE (High-Density Polyethylene)
Barrel Temperature: 180–200°C, 200–230°C, 210–240°C
Nozzle Temperature: 210–230°C
Mold Temperature: 40–60°C
Melt Temperature: 200–230°C
Injection Pressure: 80–140 MPa (up to 180 MPa for thin-wall parts)
Holding Pressure: 40–70 MPa
Back Pressure: 0.3–0.6 MPa
Screw Speed: 80–200 rpm
Drying: No drying required if moisture content ≤ 0.3%
4. ABS (Acrylonitrile-Butadiene-Styrene)
Barrel Temperature: 180–210°C, 200–240°C, 210–250°C
Nozzle Temperature: 210–240°C
Mold Temperature: 45–70°C
Melt Temperature: 220–245°C
Injection Pressure: 90–130 MPa
Holding Pressure: 40–70 MPa
Back Pressure: 0.5–1.0 MPa
Screw Speed: 50–120 rpm
Drying: Dry at 75–80°C for 2–4 hours (mandatory; otherwise, silver streaks will occur)
5. PS (Polystyrene / Clear Polystyrene)
Barrel Temperature: 170–190°C, 180–220°C, 190–230°C
Nozzle Temperature: 190–220°C
Mold Temperature: 30–50°C
Melt Temperature: 190–230°C
Injection Pressure: 70–110 MPa
Holding Pressure: 30–50 MPa
Back Pressure: 0.3–0.8 MPa
Screw Speed: 60–180 rpm
Drying: No drying required
6. PVC (Polyvinyl Chloride, Flexible / Rigid)
Barrel Temperature: 140–160°C, 150–170°C, 160–180°C (strictly no higher than 200°C to avoid decomposition)
Nozzle Temperature: 160–180°C
Mold Temperature: 20–45°C (30–50°C for rigid material)
Melt Temperature: 160–190°C
Injection Pressure: 80–120 MPa
Holding Pressure: 40–60 MPa
Back Pressure: 0.2–0.5 MPa
Screw Speed: 20–60 rpm (low speed to prevent overheating)
Drying: Generally no drying required
II. Engineering Plastics (PC/PA6/PA66/POM/PBT/PET)
7. PC (Polycarbonate)
Barrel Temperature: 250–270°C, 270–290°C, 280–300°C
Nozzle Temperature: 280–300°C
Mold Temperature: 70–95°C (90–120°C for high surface quality)
Melt Temperature: 280–305°C
Injection Pressure: 100–160 MPa
Holding Pressure: 50–80 MPa
Back Pressure: 0.8–1.5 MPa
Screw Speed: 40–100 rpm
Drying: Dry at 100–120°C for 3–6 hours (mandatory; moisture content < 0.02%)
8. PA6 (Nylon 6)
Barrel Temperature: 220–240°C, 230–260°C, 240–270°C
Nozzle Temperature: 240–260°C
Mold Temperature: 60–90°C
Melt Temperature: 240–270°C
Injection Pressure: 90–140 MPa
Holding Pressure: 40–70 MPa
Back Pressure: 0.5–1.0 MPa
Screw Speed: 50–120 rpm
Drying: Dry at 80–90°C for 4–6 hours (moisture content < 0.1%)
9. PA66 (Nylon 66)
Barrel Temperature: 230–250°C, 240–270°C, 250–280°C
Nozzle Temperature: 250–270°C
Mold Temperature: 70–100°C
Melt Temperature: 250–280°C
Injection Pressure: 100–150 MPa
Holding Pressure: 50–80 MPa
Back Pressure: 0.8–1.2 MPa
Screw Speed: 40–100 rpm
Drying: Dry at 85–95°C for 4–6 hours
10. POM (Polyoxymethylene, Homopolymer / Copolymer)
Barrel Temperature: 160–180°C, 170–200°C, 180–210°C
Nozzle Temperature: 180–200°C
Mold Temperature: 50–70°C
Melt Temperature: 190–210°C
Injection Pressure: 80–120 MPa
Holding Pressure: 40–60 MPa
Back Pressure: 0.3–0.8 MPa
Screw Speed: 60–150 rpm
Drying: Dry at 80°C for 2–3 hours (low moisture absorption; drying is optional)
11. PBT (Polybutylene Terephthalate)
Barrel Temperature: 220–240°C, 230–250°C, 240–260°C
Nozzle Temperature: 240–260°C
Mold Temperature: 50–80°C
Melt Temperature: 250–265°C
Injection Pressure: 100–140 MPa
Holding Pressure: 50–80 MPa
Back Pressure: 0.5–1.0 MPa
Screw Speed: 50–120 rpm
Drying: Dry at 120–130°C for 3–5 hours
12. PET (Polyethylene Terephthalate)
Barrel Temperature: 250–270°C, 260–280°C, 270–290°C
Nozzle Temperature: 270–285°C
Mold Temperature: 80–120°C
Melt Temperature: 270–290°C
Injection Pressure: 120–180 MPa
Holding Pressure: 60–100 MPa
Back Pressure: 0.8–1.5 MPa
Screw Speed: 60–150 rpm
Drying: Dry at 130–140°C for 4–6 hours (mandatory deep drying)
Summary
General-purpose plastics have relatively low requirements for molding temperature and pressure, most do not require strict drying, and there is a large adjustment range for molding parameters. The key points are controlling mold temperature and injection speed for stable production. Engineering plastics generally have hygroscopic properties; materials such as PC, PA, PBT, and PET must be fully dried as required, otherwise defects such as bubbles, silver streaks, and cracking will easily occur. Meanwhile, molding temperature and injection pressure should be appropriately increased to ensure plasticization and filling effects. PVC and POM are heat-sensitive materials; excessively high temperatures and fast screw speeds should be avoided during production to prevent material decomposition at high temperatures, which produces odors and harmful substances. In actual production, minor adjustments can be made within the parameter ranges of the table according to the age of the machine, mold structure, and differences in material brands. Increase temperature and pressure appropriately for glass fiber-reinforced materials, increase injection pressure and speed for thin-wall parts, and slow down injection speed and extend cooling time for thick-wall parts. This can adapt to the vast majority of injection molding production scenarios.
