Low-Friction HDPE Cutting Board Polyethylene HDPE

【English Abbreviation】HDPE

 

【Full Chinese Name】High-Density Polyethylene  

 

【Common Common Name】Low-Pressure Ethylene  

 

【Monomer Composition】Ethylene  

 

【Basic Properties】High-Density Polyethylene is an opaque white waxy material with a density lower than water, ranging from 0.941 to 0.960. It is soft and flexible but slightly harder than LDPE and has slightly less elongation. It is non-toxic and odorless.

 

【Combustion Characteristics】Flammable; continues burning after removal from flame. The flame has a yellow upper part and a blue lower part. It melts during combustion, with liquid droplets falling, no black smoke emitted, and emits a wax-like odor.

 

【Main Advantages】Resistant to acids and alkalis, resistant to organic solvents, excellent electrical insulation properties, and maintains some flexibility at low temperatures. Surface hardness, tensile strength, rigidity, and other mechanical properties are higher than LDPE,接近PP, more flexible than PP, but surface smoothness is inferior to PP.

 

【Main Disadvantages】Poor mechanical properties, poor breathability, prone to deformation, aging, and brittleness, with lower brittleness than PP, prone to stress cracking, low surface hardness, and prone to scratches. Difficult to print; surface discharge treatment is required during printing; cannot be electroplated; surface lacks luster.

 

【Applications】Used for extruded packaging films, ropes, woven bags, fishing nets, water pipes; injection-molded low-grade daily necessities and housings, non-load-bearing components, plastic boxes, and pallet boxes; extruded blow-molded containers, hollow products, and bottles.

 

【Injection Molding Process】HDPE has countless applications, ranging from reusable thin-walled beverage cups to 5-gallon containers, accounting for 1/5 of domestically produced HDPE. Injection molding grades typically have a melt index of 5–10, with grades featuring lower flow and higher flow for improved processability. Applications include thin-walled packaging for daily necessities and food; durable, flexible food and paint cans; and high environmental stress crack resistance applications, such as small engine fuel tanks and 90-gallon trash cans.

 

The melting point of general HDPE is 142°C, and the decomposition temperature is 300°C; the adjustable temperature range for injection molding is relatively wide. During injection molding, the typical operating temperature is 180°C–230°C; as an olefin-based plastic, it does not absorb water, so drying is not required during production. However, to ensure product quality, it can be dried at 60°C for 1 hour to remove surface moisture. Polyethylene has high melt viscosity and a low flow length ratio, so thin-walled products may experience insufficient material flow, resulting in larger gates and runners. The material is prone to static electricity and surface dust accumulation. The shrinkage rate is 16‰, and the flash allowance is 0.05 mm.

 

 

High-density polyethylene (HDPE) exhibits excellent heat resistance and cold resistance, along with good chemical stability. It also possesses high rigidity and toughness, as well as superior mechanical strength. Its dielectric properties and resistance to environmental stress cracking are also commendable. Its hardness, tensile strength, and creep resistance are superior to those of low-density polyethylene; its abrasion resistance, electrical insulation, toughness, and cold resistance are also good, but its electrical insulation properties are slightly inferior to those of low-density polyethylene; it has excellent chemical stability, being insoluble in any organic solvent at room temperature and resistant to corrosion by acids, alkalis, and various salts; its film has low permeability to water vapor and air, and low water absorption; it has poor aging resistance and inferior environmental crack resistance compared to low-density polyethylene, especially under thermal oxidation, which degrades its performance. Therefore, antioxidants and UV absorbers must be added to the resin to improve these shortcomings. High-density polyethylene film has a lower heat distortion temperature under stress, which should be noted during application.