5 Major Commodity Plastics （PP、PE、PS、PVC、ABS）

Commodity plastics dominate over 70% of global plastic consumption due to their low cost, high production volume, and ease of processing. Below are their core characteristics and primary applications:

1. Polypropylene (PP)

Polypropylene (PP) is a thermoplastic synthetic resin primarily produced through the polymerization of propylene.

Key Properties:

• Lightweight (density: 0.9 g/cm³, floats on water)
  
• Excellent chemical resistance (resists acids, alkalis, and organic solvents)
  
• Heat-resistant (long-term use at 100–120°C)
  
• Semi-rigid (good toughness but brittle at low temperatures)
  
• High crystallinity (shrinkage rate: 1.5%–3%, prone to sink marks)

Typical Applications:

• Packaging: Microwave-safe food containers, bottle caps, stretch films
• Automotive: Bumpers, interior parts, battery casings
• Consumer goods: Disposable syringes, straws, toys (e.g., LEGO alternative parts)

Drawbacks:

• Prone to UV degradation (requires stabilizers)
• Poor transparency (modified into CPP for clarity).

2. Polyethylene (PE)

Polyethylene (PE) is a common plastic. According to its density and structure, it can be divided into low-density polyethylene (LDPE), high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE).

Comparison:

Advantages:

• Non-toxic (FDA-approved for food contact)
• Low-temperature flexibility (remains ductile at -50°C)
• Excellent electrical insulation (used in cables)

Drawbacks:

• Low heat resistance (HDPE softens at ~80°C)
• Susceptible to environmental stress cracking.

3. Polystyrene (PS)

Polystyrene (PS) is a lightweight, transparent plastic with good insulation and processability.

Types:

• GPPS (General Purpose PS): Transparent but brittle – used in CD cases, cosmetic bottles
• HIPS (High Impact PS): Rubber-modified for toughness – used in refrigerator liners, toys

Key Properties:

• High transparency (90% light transmission, glass-like)
• Easy processing (excellent flowability)
• Low cost (cheaper than PP/PE)

Drawbacks:

• Brittle (prone to cracking)
• Poor solvent resistance (damaged by gasoline/alcohol).

4. Polyvinyl Chloride (PVC)

PVC offers excellent chemical stability and mechanical strength, widely used in pipes, cables, and medical devices.

Types:

Key Properties:

• Self-extinguishing (chlorine content inhibits burning)
• Weather-resistant (lasts over 10 years outdoors)

Drawbacks:

• Poor thermal stability (requires stabilizers during processing)
• Environmental concerns (dioxin release when incinerated).

5. ABS (Acrylonitrile Butadiene Styrene)

ABS is a versatile thermoplastic with balanced mechanical properties, widely used in toys, automotive parts, and electronics.

Key Properties: Synergistic effects of three components

• Acrylonitrile (A): Chemical resistance & hardness
• Butadiene (B): Impact resistance (remains tough at -40°C)
• Styrene (S): Easy processing & glossy surface

Key Properties: Well-rounded performance

• Stronger than PP/PS, suitable for plating/painting
• Low shrinkage (0.4%–0.8%), dimensionally stable

Typical Applications:

• Electronics: Keyboard keys, charger housings
• Automotive: Dashboards, grilles
• Consumer goods: LEGO bricks, luggage

Drawbacks:

• Poor UV resistance (requires modification for outdoor use)
• 30%–50% more expensive than PP/PS.

Comparative Summary of Commodity Plastics

Quick Commodity Plastics Material Selection Guide

Need low cost? → PE/PS

Need heat resistance? → PP/ABS

Need transparency? → PS/GPPS

Need toughness? → ABS/HDPE

Need flame retardancy? → PVC/modified ABS

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