How to distinguish between 4 common plastic materials: what is difference between polyethylene (PE) , polyvinyl chloride (PVC), polypropylene (PP) and polystyrene (PS)?
Common industrial plastics: polyethylene (PE) , polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS) have different chemical properties and are used in different products.
Polypropylene, called PP. Thermoplastic resin obtained by polymerization of propylene. White translucent, waxy if not pigmented, lighter than polyethylene. The transparency is also better than polyethylene (PE) and is harder than polyethylene (PE). Common products: pots, barrels, furniture, films, woven bags, bottle caps, car bumpers, etc.
Polyethylene, called PE. It is an ethylene polymer, non-toxic. Easy to paint, good chemical resistance, frost resistance, radiation resistance, good electrical insulation. It is suitable for packaging materials for food and medicine, tableware, medical equipment and insulating materials for electronics industry.
Polyvinyl chloride, called PVC. It is a polymer of vinyl chloride. Polyvinyl chloride (PVC) is a synthetic material with many advantages, making it an ideal material for engineering plastics. Good chemical stability, resistance to acids, alkalis and some chemicals. Moisture resistance, aging resistance, fire resistance. During use, temperature should not exceed 60°C, and at low temperatures it hardens. PVC is divided into soft plastic and hard plastic. The soft ones are mainly made from films that are used as packaging materials, waterproof materials, films for growing crops, etc., and can also be used as insulating layers for cables and wires, as well as artificial leather products. The solids are commonly made into pipes and plates, which are used as plumbing and corrosion-resistant pipes for liquids, and plates are used as cladding and floors for various tanks. Other related: natural color light yellow translucent, shiny. Transparency is better than polyethylene and polystyrene, and worse than polystyrene. Depending on amount of additives, it can be divided into soft and hard PVC. Soft products are soft and hard, and sticky to touch. Hard products have higher hardness, than products with low density. polyethylene., and below polypropylene there will be whitening at inflection. Common products: plates, pipes, soles, toys, doors and windows, wire shells, stationery, etc.
Polystyrene, called PS. Transparent when not shaded. When product is dropped or hit, a clear sound is heard, like metal. The luster and transparency are very good, like glass, fragile and easy to break, and surface of product can be painted with fingernails. Modified polystyrene is opaque. General products: stationery, cups, food containers, appliance cases, electrical accessories, etc.
A look. See if there is a product description on it, if it is covered with PE cling film or plastic wrap, then you can safely use it, if PVC is written or there is no material, try not to buy.
Two "touches". PE food film generally has poor viscosity and transparency, and is easy to open after being rubbed with hands, while PVC food film has better transparency and viscosity, it is not easy to unfold after being rubbed with hands, and it is easy to stick. to hands.
Three "fires". After igniting polyethylene food film, flame becomes yellow and does not go out when it is away from fire source. Yellow-green, relatively large smoke, no oil droplets, goes out after exiting fire. source and has a strong pungent odor.
In addition, PVC film sticks easily to dust and is difficult to clean. After long-term use, its light transmission is often worse than that of polyethylene film.