Yip Chemical | Masterbatch and Carbon Black Supplier 
Below is a Common Plastic Molding Shrinkage Rate Table (注塑缩水率表)
for the resins most frequently used with carbon black and black masterbatch
in injection molding, pipe, film and extrusion applications. Values are linear mold shrinkage
after cooling to room temperature (reference ASTM D955/ ISO 294-4; actual number varies with
wall thickness, gate location, mold temp, holding pressure and filler loading).
Common Thermoplastic Shrinkage Rate Table
| Material (EN / CN) | Abbr. | Shrinkage Rate (%) | Type | Note for black masterbatch user |
| Polypropylene (聚丙烯) | PP | 1.0 – 2.5 | Semi-crystalline | Highest-volume base for black MB; flow vs transverse shrinkage gap large |
| PP + 30% Glass Fiber | PP-GF30 | 0.4 – 0.8 | Reinforced | Fiber cuts shrinkage sharply |
| Low-Density Polyethylene (低密度聚乙烯) | LDPE | 1.5 – 3.5 | Semi-crystalline | Film & bag grade, high shrink |
| High-Density Polyethylene (高密度聚乙烯) | HDPE | 1.5 – 3.0 | Semi-crystalline | Pipe & drum grade, common for UV-black MB |
| General Purpose Polystyrene (通用聚苯乙烯) | GPPS | 0.3 – 0.6 | Amorphous | Low shrink, brittle |
| High Impact PS (高抗冲聚苯乙烯) | HIPS | 0.4 – 0.7 | Amorphous | Slightly higher than GPPS |
| ABS (丙烯腈-丁二烯-苯乙烯) | ABS | 0.4 – 0.9 | Amorphous | Electronics housings, near-isotropic |
| PC / ABS Alloy | PC/ABS | 0.4 – 0.7 | Amorphous | Auto interior, tight tolerance |
| Polycarbonate (聚碳酸酯) | PC | 0.5 – 0.7 | Amorphous | Optical & structural, low shrink |
| Rigid PVC (硬聚氯乙烯) | PVC-U | 0.1 – 0.6 | Amorphous | Corrosive off-gas, needs SS tooling |
| Flexible PVC (软聚氯乙烯) | PVC-P | 1.0 – 2.5 | Amorphous | Plasticizer-driven wide range |
| Polyamide 6 (尼龙6) | PA6 | 0.7 – 1.5 (up to 2.5) | Semi-crystalline | Moisture absorption causes post-mold shrink |
| PA6 + 30% GF | PA6-GF30 | 0.3 – 0.6 | Reinforced | |
| Polyamide 66 (尼龙66) | PA66 | 1.0 – 1.6 (up to 2.5) | Semi-crystalline | |
| PA66 + 30% GF | PA66-GF30 | 0.3 – 0.6 | Reinforced | |
| Polyoxymethylene / Acetal (聚甲醛) | POM | 1.8 – 2.5 | Semi-crystalline | Gear & clip grade, high shrink |
| PET (crystalline, 结晶PET) | PET | 1.2 – 2.0 | Semi-crystalline | Bottle & fiber grade |
| PBT (聚对苯二甲酸丁二醇酯) | PBT | 1.2 – 2.2 | Semi-crystalline | Connector grade |
| PMMA (亚克力) | PMMA | 0.2 – 0.8 | Amorphous | Signage & lens |
| PPS (聚苯硫醚) | PPS | 0.6 – 1.4 | Semi-crystalline | High-temp grade |
| TPU (热塑性聚氨酯) | TPU | 0.8 – 1.8 | Semi-crystal / block | Shore hardness shifts value |
Quick rule: Amorphous resins (ABS, PC, PS, PMMA, rigid PVC) → 0.1–0.9%.
Semi-crystalline resins (PP, PE, PA, POM, PBT) → 1.0–3.5%.
Glass fiber / mineral filler normally halves or more the shrinkage.
Shrinkage Change When Using Carbon Black / Black Masterbatch
When you add black masterbatch or recycled carbon black (rCB) concentrate to a natural resin,
the final shrink rate is not the resin datasheet number exactly:
Normal let-down (1–5% MB, 40% CB masterbatch) → shrinkage shift is small, usually within ±0.1%.
Mold design can keep the virgin-resin shrink value.
Wrong carrier choice (e.g. PE-carrier black MB in PP, or recycled-carrier MB) → poor dispersion, streaking,
local shrinkage variation, warpage.
Over-dose black MB (>7–8% in injection parts) → surface dulling, brittle edge, unpredictable shrink variance.
Mold Sizing Formula
Cavity Dimension=Target Part Size×(1+S)
Where S= chosen shrinkage rate (use mid-range of table, then tune by trial shot).
Example: PP part 100 mm long, pick S = 1.8% → cavity length ≈ 101.8 mm.
Yipchem Note (Carbon Black & Black Masterbatch)
For PP, HDPE, LDPE, ABS and PA black molding jobs, carrier-matched black masterbatch
keeps the shrinkage behavior close to the base resin and avoids anisotropic warpage.
Yipchem supplies carbon black powder, rCB-based and virgin-CB black masterbatch
with PE / PP / ABS carrier options, N330/N550/N660 and
high-jetness N220 grades for pipe, film, injection and conductive applications.
👉 Check resin-carrier matching and grade selection here: https://www.yipchem.com