Mục lục
PE (polyethylene) is a thermoplastic polymer produced by polymerising ethylene gas, and it is the highest-volume plastic manufactured globally. Its properties - flexibility, moisture resistance, and chemical inertness - vary significantly by density grade, which determines whether it is used as a rigid industrial pipe, a soft food-wrap film, or an engineering wear liner.
1. What Is PE Plastic? Molecular Structure and Classification
Polyethylene is built from repeating -CH2-CH2- units. The degree to which polymer chains branch determines crystallinity, which in turn controls density, rigidity, and application. The table below covers the four grades most relevant to industrial and packaging buyers.
| PE Grade | Density (g/cm3) | Structure and Key Properties | Typical Applications |
|---|---|---|---|
| HDPE (High-Density) | 0.940 - 0.970 | Linear chains, rigid, excellent moisture barrier, high chemical resistance | Industrial drums and containers, pressure pipes, heavy-duty packaging |
| LDPE (Low-Density) | 0.910 - 0.940 | Branched chains, highly flexible, soft and transparent | Stretch wrap film, food-contact film, medical gloves, soft bags |
| UHMWPE (Ultra-High Molecular Weight) | > 0.930 | Extremely long chains, abrasion resistance up to 15x that of steel | Engineering components, conveyor liners, wear pads |
| PEX (Cross-linked) | 0.940 - 0.960 | Chemically cross-linked; withstands elevated temperature and pressure | Hot-water pipes, electrical cable insulation |
Advantages and Limitations - Key Technical Indicators
Practical experience with PE in packaging and industrial use shows two distinct sides:
- Strengths: PE provides an excellent moisture barrier, making it ideal for liquid storage. Its flexibility and chemical resistance make it reliable in demanding environments. Virgin PE grades are food-safe.
- Limitations: PE has relatively poor heat resistance. HDPE melts at approximately 120-135 degrees C, and containers can deform at lower temperatures under sustained heat. PE also tends to absorb odours if not cleaned and stored correctly.
PE vs PP: Core Differences in Application
Both PE and PP (polypropylene) belong to the polyolefin family, yet they differ substantially in performance. PP withstands higher temperatures (typically above 160 degrees C) and is stiffer and less flexible than PE. This makes PP the preferred choice for sterilisable applications such as food containers and medical instruments, whereas PE outperforms PP in flexibility and cold-moisture resistance - qualities that suit stretch film, bottles, and cold-store liners.
How to Identify PE by Sensory Testing
Beyond reading the resin identification codes (2 for HDPE, 4 for LDPE), PE can be identified by simple sensory tests. PE feels soft and waxy to the touch, and it floats on water due to its low specific gravity. When burned, it produces a blue-edged flame and a smell similar to melting paraffin wax. These are the most accessible field tests for distinguishing PE from other plastics.
2. PE Plastic and Human Health
The question of whether PE is safe must be answered with evidence, not speculation.
Is PE Plastic Toxic?
Virgin PE (HDPE and LDPE) is classified as food-safe by the US Food and Drug Administration (FDA). A critical fact for buyers is that PE contains no BPA (Bisphenol A) and no phthalates - the two chemical groups most commonly associated with health concerns in plastics. This makes virgin PE a reliable material for food packaging, children’s products, and medical consumables when used correctly.
Safe Use Practices and Heat Risk
- Heat warning: Because PE has low heat resistance, avoid using PE containers with hot food or reheating food in a microwave. Deformation under heat may compromise the integrity of the packaging.
- Cleaning PE containers: Wash with warm water and mild soap. Avoid prolonged contact with strongly scented substances, as PE can absorb odours that are difficult to remove.
3. Applications of PE Plastic Across Industries
PE serves virtually every sector because it balances cost, processability, and functional performance effectively.
- Packaging: Stretch wrap film and food-contact film (LDPE) are among the most widely used PE products globally. ICD Vietnam supplies PE stretch wrap film for pallet unitisation in manufacturing and distribution.
- Industrial: HDPE pipes and large chemical storage drums rely on the grade’s rigidity and chemical resistance. UHMWPE is used for wear-resistant liners in conveyor systems.
- Agriculture and healthcare: PE greenhouse film and mulch film are standard in modern farming. In healthcare, PE is used for pharmaceutical bottles and single-use consumables, where its food-safe status is essential.
4. Market, Pricing and Sustainability
PE pellet prices track crude oil prices and global supply closely. The table below shows reference price ranges in Vietnam at the time of publication (VND/kg). These are indicative only - contact suppliers directly for current quotes by volume.
| PE Grade | Quality | Reference Price (VND/kg) | Typical Application |
|---|---|---|---|
| HDPE pellets | Virgin | 32,000 - 38,000 | Drums, containers, pressure pipes |
| LDPE pellets | Virgin | 34,000 - 40,000 | Food-contact film, soft packaging |
| HDPE pellets | Recycled (Grade 1) | 22,000 - 28,000 | Waste bins, non-food industrial products |
| LDPE pellets | Recycled (Grade 1) | 24,000 - 30,000 | Refuse bags, agricultural mulch film |
Prices are reference values only and are not a formal quotation. Contact your supplier directly for pricing based on volume and timing.
Import, HS Code and Pricing Factors
For buyers importing PE resin, the correct HS code (Chapter 39 of the Harmonised System) and applicable tariff rate are key cost determinants. Buyers should obtain formal quotes from reputable suppliers and clearly distinguish between virgin and recycled pellet pricing, as quality and mechanical properties differ significantly between the two.
PE Recycling and Environmental Impact
PE is one of the most recyclable plastics in commercial use - resin codes 2 (HDPE) and 4 (LDPE) are both widely accepted by recycling programmes. The recycling process involves collection, cleaning, melting, and re-pelletising. Recycled PE is an economically viable material for non-food applications, but quality must be controlled carefully to avoid contamination risk in sensitive end uses.
Related Articles
| PE Stretch Wrap Film - ICD Vietnam | What Is a Pallet? Types and Specifications | Danpla (Corrugated Plastic Sheet) Guide |
Frequently Asked Questions
1. What is PE plastic (polyethylene)?
PE (polyethylene) is a thermoplastic polymer produced by polymerising ethylene gas. It is the world’s highest-volume plastic, valued for its flexibility, moisture resistance, and chemical inertness. It is sold as pellets for conversion into film, pipe, containers, and engineering components.
2. How many types of PE plastic are there?
The main commercial grades are HDPE (high-density), LDPE (low-density), LLDPE (linear low-density), MDPE (medium-density), VLDPE (very low-density), UHMWPE (ultra-high molecular weight), and PEX (cross-linked). The grade is determined by density and chain structure, which control stiffness, flexibility, and heat resistance.
3. Is PE plastic toxic? Is it safe for food contact?
Virgin HDPE and LDPE are classified as food-safe by the US FDA. PE contains no BPA and no phthalates. It is widely used for food packaging, pharmaceutical containers, and children’s products. Recycled PE should not be used in direct food contact unless certified food-grade.
4. What temperature can PE plastic withstand?
HDPE melts at approximately 120-135 degrees C, and LDPE at a lower range. Both grades deform under sustained heat well below the melting point. Avoid using PE containers with hot food or heating them in a microwave.
5. How do you tell PE plastic apart from other plastics?
PE feels soft and waxy, floats on water, and burns with a blue-edged flame and a paraffin-like smell. PP (polypropylene) is stiffer and withstands higher temperatures. The resin codes embossed on products also identify the material: 2 for HDPE, 4 for LDPE.
6. What is the difference between virgin and recycled PE pellets?
Virgin PE pellets are produced directly from ethylene, offering maximum purity, consistency, and mechanical performance, and are suitable for food-contact use. Recycled PE pellets are reprocessed from used PE products; they cost less but have variable quality and reduced mechanical properties, and are not suitable for direct food contact.
7. Can PE plastic be recycled?
Yes. PE is among the most readily recyclable plastics. HDPE (code 2) and LDPE (code 4) are accepted by most commercial recycling streams. The process involves collection, cleaning, melt extrusion, and re-pelletising. Recycled PE is suitable for non-food applications such as refuse bags, agricultural film, and industrial containers.
8. What should I watch out for when using PE products?
Avoid filling PE containers with very hot liquids or reheating food inside them. Clean PE containers with warm water and mild detergent, and avoid prolonged exposure to strong-smelling substances, as PE can absorb odours that are difficult to eliminate.
Contact ICD Vietnam
Hotline: 0983 797 186 / 090 345 9186 / 090 5859 186
Email: sales@icdvietnam.com.vn | Zalo: Chat Zalo
