1. Basic Overview
PP stands for Polypropylene, a lightweight semi-crystalline thermoplastic polymer made from propylene monomers. It is one of the most widely used general-purpose plastics, affordable and versatile. There are three main types:
- Homopolymer PP: High rigidity, good tensile strength, used for rigid containers and structural parts.
- Copolymer PP (Random Copolymer): Transparent, better low-temperature toughness, ideal for food packaging.
- Impact Copolymer PP: Excellent crack resistance under cold conditions, applied to auto parts and crates.
2. Key Advantages
- Very Low Weight Density only 0.90–0.91 g/cm³, lighter than water, the lightest common commercial plastic.
- Low moisture absorption Hardly absorbs water, maintains stable dimensions in humid surroundings.
- Outstanding chemical resistance Resistant to dilute acids, alkalis, detergents, oils and most organic solvents; does not corrode easily.
- High heat tolerance for food use Heat deflection temperature around 100°C, microwave-safe, suitable for food containers and disposable tableware.
- Good fatigue & hinge resistance Unique “living hinge” property—thin PP strips can fold millions of times without breaking, widely used for flip lids of boxes.
- Easy processing & recyclable Suitable for injection molding, extrusion, blow molding, thermoforming; fully recyclable plastic marked with resin code 5.
- Non-toxic & food-safe Compliant with food contact standards, no harmful substances under normal temperature.
3. Disadvantages
- Poor low-temperature performance: becomes brittle below -10℃ without modification.
- Weak anti-UV capability: prone to aging, yellowing and cracking under prolonged sunlight exposure.
- Low surface hardness, easy to scratch.
- Difficult to paint or glue without surface treatment.
4. Main Applications
Food & Daily Packaging
Microwave lunch boxes, beverage bottles, yogurt cups, plastic food crates, straws, storage containers.
Automotive Parts
Car bumpers, interior trim, battery casings, fan blades, luggage racks.
Industrial & Logistics
Plastic pallets, turnover boxes, injection molded housings, chemical storage tanks.
Consumer Goods
Foldable storage boxes, bottle flip caps, furniture, disposable masks non-woven fabric.
Medical Supplies
Disposable syringes, medical specimen tubes, surgical instrument packaging.
5. Basic Physical Parameters (Reference)
- Density: 0.90–0.91 g/cm³
- Melting point: 167°C
- Continuous working temperature: -10℃ ~ 100℃
- 24h water absorption: <0.01%
PP Material Parameter Table
| Parameter | Reference Specifications |
|---|---|
| Price | Cost varies with PP grade, component weight, machining complexity and order quantity |
| Delivery time | Prototypes: 3–5 working days; Mass production: 7–12 working days |
| Wall thickness | Minimum 1.2 mm; optimal range 2–6 mm; Uneven thick walls easily cause shrinkage dents and deformation |
| Tolerance | Standard tolerance ±0.10 mm; Precision tolerance ±0.04–0.06 mm with extra fees, follows ISO 2768-m |
| Maximum part size | CNC solid sheet/block/rod processing: 1200 × 1000 × 300 mm |
| Available PP Grades | 1. Homopolymer PP: high rigidity, good heat resistance2. Copolymer PP: excellent low-temperature impact resistance3. Glass-fiber-reinforced PP (10%/20%/30% GF): improved dimensional stability4. Food-grade PP: non-toxic, suitable for food contact parts5. Color-modified PP: natural, black, blue and other custom colors6. Anti-static PP for electronic jigs |