2.  Compression Molding: Polyethylene raw material is placed into a mold, heated and pressurized in a hot press to melt, flow, and fill the cavity, then demolded after cooling. Suitable for producing small batches, large thickness (>50mm) sheets, or parts requiring specific inserts .

Material Types and Specification System

Type	Molecular Weight/Characteristics	Typical Thickness/Diameter Range (mm)	Width × Length (mm)	Main Production Method	Main Application Areas
HDPE Sheet (General Grade)	MW ~300-500k, high crystallinity	1 - 100	1000×2000 / 1300×3000	Extrusion/Compression	Corrosion-resistant linings, cutting boards, insulating gaskets, tanks
UHMW-PE Sheet (Wear-Resistant Grade)	MW > 3 million, exceptional wear resistance	5 - 120	1000×2000 / Custom	Compression/Extrusion	Chute liners, wear-resistant guides, hopper liners, ice rink dasher boards
Antistatic/Conductive Type	Carbon fiber/carbon black filled, surface resistance 10³-10⁶ Ω	1 - 60	1000×2000 / 1220×2440	Compression/Extrusion	Electronic production line fixtures, semiconductor trays, explosion-proof partitions
Food Grade/Medical Grade	Meets FDA/ISO10993 standards, high purity	2 - 50	1000×2000	Extrusion	Cutting boards, food conveyor belts, medical device components
Flexible PE Sheet (LDPE/LLDPE)	Low density, soft texture	0.2 - 10	Rolls/Sheets	Calendering/Blow molding	Sealing gaskets, cushioning pads, waterproofing membranes

 

Technical Parameters and Performance Indicators

Physical & Mechanical Properties

Property	HDPE Sheet Typical Value	UHMW-PE Sheet Typical Value	Test Standard/Reference
Density (g/cm³)	0.94 - 0.96	0.93 - 0.94	ASTM D792
Tensile Strength (MPa)	17 - 40	20 - 45	ISO 527
Elongation at Break (%)	> 350	> 300	ISO 527
Flexural Strength (MPa)	27 - 35	25 - 35	ISO 178
Impact Strength (Notched, kJ/m²)	No break - 20	No break - >100	ISO 179
Shore Hardness (D)	60 - 70	60 - 65	ASTM D2240
Coefficient of Friction	0.20 - 0.30	0.10 - 0.20	ASTM D1894
Water Absorption (24h, %)	< 0.01	< 0.01	ASTM D570

Thermal & Electrical Properties

Property	Typical Value/Range	Test Standard/Reference
Melting Point (℃)	130 - 135 (HDPE) / 135 - 145 (UHMWPE)	DSC
Long-term Service Temp (Air, ℃)	-100 to 80 (HDPE) / -150 to 90 (UHMWPE)	—
Heat Deflection Temp (0.46MPa, ℃)	60 - 80	ASTM D648
Coefficient of Linear Expansion (10⁻⁵/K)	12 - 20	ASTM D696
Thermal Conductivity (W/m·K)	0.40 - 0.45	ASTM C177
Dielectric Strength (kV/mm)	45 - 65	ASTM D149
Volume Resistivity (Ω·cm)	> 10¹⁵	ASTM D257
Dielectric Constant (1MHz)	2.3 - 2.4	ASTM D150

Typical Application Areas

Application Field	Specific Uses	Recommended Type	Key Requirements
Food Processing	Cutting boards, work surfaces, food conveyor belts, star wheels, screws	Food Grade HDPE	FDA certification, no leaching, easy cleaning
Bulk Material Handling	Hopper/chute liners, dump truck bed liners, vibratory feeder bases	UHMW-PE Wear-Resistant	Exceptional wear resistance, low friction, impact resistance
Semiconductor/Electronics	Wafer cleaning tanks, antistatic trays, PCB fixtures, jigs	Antistatic Type	Stable surface resistance, no particle shedding
Chemical Anti-Corrosin	Tank/reactor linings, acid/alkali baths, pipe gaskets, seals	HDPE General Grade	Chemical corrosion resistance, good weatherability
Cold Chain Logistics	Freezer box liners, freezer partitions, LNG storage seals	HDPE/UHMW-PE	No brittleness at -196°C, dimensional stability
Medical Devices	Artificial joints (acetabular cups), surgical instrument handles, prosthetic sockets	Medical Grade UHMW-PE	Biocompatibility, wear resistance, sterilizable
Port/Marine Machinery	Fenders, wear strips, bollard pads, crane sliders	UHMW-PE	Seawater corrosion resistance, impact resistance, self-lubrication
Sports & Recreation	Ice rink dasher boards, ski base material, slides, climbing walls	HDPE/UHMW-PE	Low-temperature resistance, weather resistance, UV resistance

Processing, Joining, and Installation Guide

1.  Machining

    - Turning/Milling: High-speed steel or carbide tools are recommended. Due to the soft and tacky nature of PE, tools should have a large rake angle (15°-25°) and a relief angle of 8°-12°. High cutting speeds (200-500 m/min) and moderate feed rates (0.1-0.3 mm/rev) are suitable. Ensure adequate cooling or use air cooling to prevent chip melting and adhesion.

    - Drilling: Use standard high-speed steel drills with a point angle of 90°-118°. A peck drilling cycle (2-3mm per peck) with chip removal is recommended. Water or compressed air can be used for cooling. The drilled hole diameter should be 0.1-0.2mm larger than the required final size to compensate for material shrinkage .

    - Sawing: Band saws or circular saws are suitable. Use coarse, wide-set teeth for good chip clearance.

2.  Joining and Assembly

    - Hot Gas Welding: The most reliable method for joining PE sheets. Use a hot air gun or extrusion welder with filler rods made of the same PE material. Weld strength can reach 85%-95% of the parent material.

    - Mechanical Fastening: Self-tapping screws or bolts can be used. Due to the softness and tendency for cold flow, it is recommended to use large washers or apply lubricant between the metal fastener and the PE surface.

    - Insert Embedding: Metal inserts can be preheated to 100-120°C and pressed into pre-drilled holes, utilizing the cooling shrinkage of PE to form a secure interference fit.

3.  Heat Treatment and Stress Relief

    - For large thickness (>50mm) or high-precision components, annealing after rough machining is recommended: hold at 80-100°C in an oven for 2-4 hours (add 1 hour per 10mm of thickness), then cool slowly to room temperature in the oven. This can eliminate >60% of internal stresses, reducing the risk of deformation or cracking during subsequent use .

4.  Installation Points

    - Liner Installation: For hopper liners, bolt heads should be countersunk 2-3mm below the PE sheet surface to prevent material hang-up. Sheet joints should be chamfered or overlapped.

    - Guide Rail Applications: When used for machinery guides, the mounting surface must be flat, and preload should be applied evenly to avoid localized stress concentrations.

Selection Decision Matrix

Application Scenario	Primary Performance Requirement	Recommended PE Grade	Key Considerations
High-Wear Hopper Liner	Extreme wear resistance, low friction	UHMW-PE (MW > 5 million)	Select sheet verified by impact abrasion test, thickness ≥ 10mm
Direct Food Contact Cutting Board	Food safety, odorless, cut resistance	Food Grade HDPE (Natural)	Request FDA certification report from supplier, avoid recycled material
Semiconductor Cleanroom Fixture	Antistatic, low particle generation	Antistatic Type (Carbon Black Filled)	Surface resistance must be stable at 10⁶-10⁹ Ω and remain so after machining
Strong Acid/Alkali Tank Lining	Chemical resistance, low permeability	HDPE General Grade	Thickness ≥ 4mm, welds must pass airtightness test
Liquid Nitrogen Environment Support	Toughness at -196°C, low thermal conductivity	HDPE/UHMW-PE	Avoid highly filled modified grades to prevent low-temperature brittleness
Underwater Plain Bearing	Self-lubrication, low water absorption	UHMW-PE	Mating surface roughness Ra ≤ 1.6μm, design appropriate clearance

Industry Customized Solutions

1.  Liner for Large Off-Highway Truck Bodies

    - Requirement: Withstand severe impact and abrasion from ore and coal, reduce vehicle dead weight, and minimize material adhesion.

    - Solution: Use 20-30mm thick UHMW-PE wear-resistant sheets, heat-formed to shape, and secured to the truck body with countersunk bolts. Leverage PE's low friction for automatic material discharge, increasing payload by over 10%.

    - Application: Heavy transport vehicles in mines and quarries.

2.  Guide Rails for Photovoltaic Panel Cleaning Equipment

    - Requirement: Long-term outdoor exposure to UV and humidity requires weather resistance, self-lubrication, and non-corrosiveness.

    - Solution: Custom-extruded HDPE guide rail profiles with UV stabilization and smooth surfaces. Ensures quiet and stable operation with robotic cleaning arms.

    - Application: Intelligent cleaning robots for large-scale photovoltaic plants.

3.  Storage Rack Pads for Spent Nuclear Fuel Pools

    - Requirement: Long-term immersion in borated deionized water requires radiation resistance, non-corrosiveness, and no abrasion to fuel rods.

    - Solution: Use high-purity, additive-free UHMW-PE sheets, precision-machined into rack pads. Their radiation resistance (cumulative dose up to 10⁵ Gy) and extremely low ionic leachables ensure nuclear safety.

    - Application: Fuel storage racks in nuclear power plants.

4.  Conveyor Star Wheels for Bottled Beverage Lines

    - Requirement: High-speed operation without scratching bottles, wear resistance, and no swelling upon contact with food-grade lubricants.

    - Solution: Use food-grade HDPE sheets, formed by 5-axis water jet cutting or CNC engraving. Smooth surfaces effectively prevent bottle tipping and jamming.

    - Application: Beverage filling and pharmaceutical packaging lines.

Storage and Maintenance

Storage Conditions

- Environment: Store in a cool, dry warehouse away from direct sunlight. Prolonged UV exposure can cause surface oxidation, discoloration, and degradation of mechanical properties .

- Placement: Sheets should be stored flat on level pallets or platforms to prevent bending deformation from long-term unsupported stacking. Stacking height for large sheets should not exceed 1 meter.

- Shelf Life: PE is chemically stable with no significant aging during storage. However, for sheets stored long-term (over 5 years), it is advisable to retest impact strength and surface hardness before critical use.

Usage and Maintenance

- Cleaning: General dirt can be cleaned with mild detergent and a soft cloth. For oil stains, alcohol or isopropyl alcohol can be used. Avoid cleaning with strong acids, strong alkalis, or organic solvents (e.g., acetone, toluene), as these can cause stress cracking or surface swelling .

- Repair: Superficial scratches can be repaired by sanding with fine-grit sandpaper or flame polishing (requires professional skill). Deep cracks or through-penetration damage cannot be repaired; the part must be replaced.

- Wear Inspection: For wear liners or guides, regularly inspect contact surfaces for wear. Although UHMW-PE is highly wear-resistant, prolonged exposure to high-speed abrasive flow will cause gradual material loss. Replacement is recommended when wear depth exceeds 1/3 of the original thickness.

- Antistatic Maintenance: The antistatic performance of antistatic PE sheets can degrade over time due to friction or contamination. Regular cleaning with mild detergent can help restore surface resistivity .

Development Trends

Technology Development Directions

1.  Pushing Molecular Weight Limits: Advancing towards PE with molecular weights exceeding 10 million to further enhance wear resistance and impact strength, expanding applications in cutting-edge fields like artificial joints and ballistic protection.

2.  Functional Compounding: Developing modified PE sheets with enhanced properties such as thermal conductivity (filled with graphene/BN), flame retardancy (with halogen-free additives), and high transparency, pushing beyond the limits of general-purpose plastics into specialized market segments.

3.  Green and Circular Economy: Researching "green polyethylene" sheets based on bio-based ethylene (e.g., from sugarcane ethanol); simultaneously exploring efficient physical recycling and chemical depolymerization technologies for waste PE sheets to achieve material circularity.

4.  Surface Engineering Innovations: Improving the printability and adhesiveness of PE sheet surfaces through flame treatment, corona treatment, or plasma treatment, enabling subsequent coating or lamination processes.

Market Application Expansion

1.  Hydrogen Storage and Transport: Utilizing HDPE's low-temperature toughness and hydrogen barrier properties to develop liners for Type IV hydrogen storage tanks, replacing traditional metal liners to achieve lightweighting for hydrogen heavy-duty trucks.

2.  Robotic Joints: The self-lubrication and wear resistance of UHMW-PE position it as a promising material for anti-friction bushings in rotational and linear joints of robots, especially humanoid robots, potentially replacing some powdered metal oil-impregnated bearings.

3.  Ocean Ranching: UHMW-PE's exceptional resistance to seawater corrosion and biofouling makes it suitable for deep-sea aquaculture cage frames, floats, etc., withstanding typhoons and harsh marine environments.

4.  Medical Implants: Highly cross-linked ultra-high molecular weight polyethylene (HXLPE) is the gold standard for artificial acetabular liners and tibial bearings in knee replacements. Next-generation antioxidant technologies extend its service life beyond 25 years.

Conclusion

PE sheets, particularly HDPE and UHMW-PE, serve as a paragon of "balancing rigidity and flexibility" among thermoplastics. With their excellent low-temperature toughness, unparalleled wear resistance, outstanding chemical stability, and food safety, they construct a vast application landscape ranging from general industrial protection to high-end medical implants. They are both the "wear-resistant armor" against sand and ore on bulk material conveyor lines, and the "sterile cutting board" safeguarding food safety on kitchen counters, and even the "artificial joints" extending life and vitality in the medical field. In the current era of "carbon neutrality" and advanced manufacturing, PE sheets are continuously pushing performance boundaries through molecular design, functional compounding, and green manufacturing, evolving towards longer life, greater intelligence, and enhanced environmental friendliness. Correct grade selection, scientific processing techniques, and targeted maintenance plans are the three core elements to fully unlocking the potential of PE sheet materials.