What is polyethylene used for

What is polyethylene used for?
① Packaging application: Packaging is the main application scenario of polyethylene, which is suitable for various packaging needs, from food to industrial products, due to its good flexibility, sealing and chemical resistance. Low density polyethylene has a soft texture and is often used to make food preservation bags and films. It has high transparency and can tightly adhere to items, reducing water loss. High density polyethylene has higher hardness, and the woven bags made from it can be used to load grain and fertilizers, with excellent tensile strength. When farmers in a certain grain producing area store wheat, they use high-density polyethylene woven bags to package it. Each bag can hold 50 kilograms, and the bag has strong moisture resistance. It is sealed with a sealing rope and stored for 3 months during the summer rainy season. The wheat does not mold or clump. Food processing plants use low-density polyethylene cling film to wrap fresh meat, which can extend the shelf life by 2-3 days in a refrigerated environment at 0-4 ℃ without chemical reactions with the meat. Polyethylene with corresponding density should be selected for different packaging scenarios to ensure a balance between packaging effect and cost.
② Application in the agricultural field: The application of polyethylene in the agricultural field runs through the entire process of planting and breeding, and its weather resistance and plasticity meet the needs of different agricultural scenarios. The main products include plastic film, greenhouse film, and aquaculture tanks. The plastic film is made of low-density polyethylene with a thickness of 0.01-0.02mm. Covering the soil surface can increase the ground temperature by 3-5 ℃, reduce water evaporation, and inhibit weed growth. When planting corn in spring in cold northern regions, laying black plastic film can not only keep warm and moist, but also inhibit weed photosynthesis through shading. Greenhouse film is mostly made of linear low-density polyethylene, with a thickness of 0.08-0.12 millimeters and a light transmittance of over 85%. It has strong aging resistance and can be used for 1-2 years after one installation. A vegetable planting base uses polyethylene greenhouse film to build a greenhouse, which can maintain a temperature of over 10 ℃ at night in winter, enabling vegetables such as cucumbers and tomatoes to be sold out of season. The aquaculture tank is made of high-density polyethylene welded together, which is corrosion-resistant, smooth and easy to clean. It is suitable for aquaculture such as fish and shrimp, and has a service life of up to 5-8 years.
③ Application in the field of architecture: Polyethylene has become an important auxiliary material in the field of architecture due to its insulation, waterproofing, and corrosion resistance, covering multiple aspects such as water supply and drainage, insulation, and waterproofing. Water supply pipes made of high-density polyethylene have smooth inner walls, low resistance, are not easy to scale, strong pressure resistance, and are suitable for temperatures ranging from -20 ℃ to 60 ℃. They are commonly used in indoor and outdoor water supply systems in residential areas and office buildings. A newly built residential area adopts polyethylene water supply pipe laying, and the pipeline connection adopts hot melt welding technology. The interface is firm without leakage, and the water quality test still meets the standards after 5 years of use. Polyethylene foam board is used for building thermal insulation with low density and thermal insulation coefficient. It is often filled in the wall interlayer or roof thermal insulation layer. After the use of civil house walls in northern cold regions, the indoor temperature in winter can be increased by 5-8 ℃. In addition, polyethylene waterproofing membrane is used for roof waterproofing, with good flexibility to adapt to slight deformation of the roof. After laying, it can form a continuous waterproof layer, effectively preventing rainwater leakage, and the service life can reach more than 10 years.
④ Application in the field of daily necessities: Polyethylene products are ubiquitous in the daily necessities field, and their low processing cost and high safety make them an ideal material for making various daily necessities. Common products include plastic pots, buckets, toys, storage boxes, etc. Plastic pots and buckets made of low-density polyethylene are lightweight and impact resistant, not easily damaged when dropped on the ground, with a smooth and easy to clean surface, suitable for daily household use. Children's toys often use food grade polyethylene, which has no odor and good toughness. Even if bitten by children, it will not release harmful substances. In a certain toy production scene, building blocks made of polyethylene were still intact after drop and compression tests, meeting safety standards. A storage box made of high-density polyethylene, with high hardness and good sealing, can be used to store clothes, books, and other items. When stacked, it can withstand high pressure and is not easily deformed. In addition, polyethylene can also be used to make disposable tableware such as plates, spoons, etc., which can be recycled and reused after use. Some biodegradable polyethylene tableware can also reduce environmental burden.
⑤ Industrial applications: Polyethylene is widely used in industries such as chemical, electronics, and machinery due to its chemical corrosion resistance and good insulation properties. In the chemical industry, storage tanks and pipelines made of high-density polyethylene can be used to store and transport corrosive media such as dilute acids, dilute alkalis, salt solutions, etc., without being corroded and without contaminating the media. A certain chemical plant uses polyethylene storage tanks to store hydrochloric acid with a concentration of 30%. The tank wall thickness is 10 millimeters, and after 3 years of use, there are no corrosion marks on the inner wall, and the purity of the medium is not affected. In the electronics industry, insulation sleeves and gaskets made of polyethylene have excellent insulation performance, which can effectively isolate current and protect electronic components. They are commonly used as outer insulation for wires and cables and gaskets for circuit boards. In the mechanical industry, polyethylene can be used to make components such as bearings and gears, with low friction coefficient and good wear resistance. It can also work normally without lubrication. The polyethylene bearings used in a certain mechanical equipment have a service life 2-3 times longer than traditional metal bearings and lower noise during operation. In addition, polyethylene can also be used as a filtering material for industrial wastewater treatment, with a filtration accuracy of up to micrometer level.
⑥ Application in the field of transportation: The application of polyethylene in the transportation field is concentrated in vehicle accessories and road facilities, and its lightweight and aging resistance meet the special needs of transportation scenarios. In vehicle accessories, bumpers and interior parts made of polyethylene are lightweight and can reduce fuel consumption. They have strong impact resistance and can absorb energy during collisions, protecting the body and passengers. In a certain vehicle production site, a car bumper made of polyethylene was only slightly deformed after collision testing and can continue to be used after repair. In road infrastructure, polyethylene road cones and isolation piers are brightly colored and resistant to sunlight and rain, and are not easily faded. When used in conjunction with reflective strips at night, they can improve the warning effect. During road maintenance in a certain city, polyethylene road cones were used to set up warning areas. After 3 months of sun and rain exposure, the color of the road cones remained bright without cracking or damage. In addition, polyethylene can also be used as a filling material for bridge expansion joints, with good flexibility to adapt to the thermal expansion and contraction of bridges, prevent rainwater from infiltrating the interior of bridges, and extend the service life of bridges.
⑦ Medical applications: Polyethylene is used in the medical field to produce various medical supplies and ensure medical safety due to its good biocompatibility and strong sterility. Common products include medical gloves, syringe casings, infusion tubes, etc. Medical gloves are made of low-density polyethylene, with a soft texture that fits snugly to the hands. They have good elasticity to ensure operational flexibility and good barrier properties to prevent cross infection between medical staff and patients. A certain hospital uses polyethylene medical gloves for surgical procedures. The gloves are undamaged and have a high degree of fit, effectively reducing the risk of infection. The syringe casing and infusion tube are made of food grade polyethylene, which has no odor and good chemical stability, and will not react with the drug solution, ensuring the purity of the drug solution. In addition, polyethylene can also be used to make medical dressings, such as breathable tape, which has good breathability and moderate adhesion. It is not easy to cause allergies when applied to the skin surface and will not damage the skin when replaced. Partial high-purity polyethylene can also be used to make pads for artificial joints, with excellent wear resistance and biocompatibility, which can improve the service life of artificial joints.