is milky white, translucent and waxy when uncolored; Touching the product by hand feels greasy, soft and tough; Slightly extensible. Generally, low density polyethylene is soft and transparent; High density polyethylene is hard.
Common products: handbags, water pipes, oil drums, beverage bottles (calcium milk bottles), daily necessities, etc.
polypropylene PP
is white, translucent and waxy when uncolored; Lighter than polyethylene. Transparency is also better than polyethylene, and it is more rigid than polyethylene.
Common products: pots, barrels, furniture, films, woven bags, bottle caps, car bumpers, etc.
polystyrene PS
is transparent when it is uncolored. When the product falls to the ground or knocks, it has a metallic crisp sound, good luster and transparency, similar to glass, brittle and easy to break, and traces can be drawn on the surface of the product with fingernails. The modify polystyrene is opaque.
Common products: stationery, cups, food containers, housing of household appliances, electrical accessories, etc.
PVC
The natural color is yellowish and translucent, with luster. Transparency is better than that of polyethylene and polystyrene, but worse than that of polystyrene. With the different amount of additives, it can be divided into soft and hard polyvinyl chloride. Soft products are soft and tough, and feel sticky. The hardness of hard products is higher than that of low-density polyethylene, but lower than that of polypropylene, and whitening will occur at the bending point.
Common products: boards, pipes, soles, toys, doors and windows, wire sheaths, stationery, etc.
Polyethylene is the most productive and widely used thermoplastic in plastics. It is a partially crystalline material polymerized from ethylene and can be processed by the molding method of general thermoplastics. Polyethylene can be divided into three categories: high density polyethylene, low density polyethylene and linear low density polyethylene.
the density of high-density polyethylene is generally higher than .94g/, while the density of low-density polyethylene and linear low-density polyethylene is between .91 and .94 g/cm. There are two main sources of waste polyethylene film:
1. Scraps and defective products produced in film production. These wastes are clean, the varieties are clear, they can be crushed and compressed and sent directly to the extruder for granulation, and the recovery process is simple.
2. Waste films from chemical industry, electrical industry, food and consumer goods industry. These waste films have been polluted, some have been colored and printed with trademarks, and some still contain impurities such as sand, sawdust or shredded paper.
Because polyethylene is cheap, easy to get and easy to form, its products are widely used, but the most used products are packaging products, which is estimated to be above 6%. High density polyethylene is mainly used in packaging films, bottles and hollow containers; The main uses of low density polyethylene are packaging film and agricultural film; Linear low density polyethylene is mainly used in films, film plastic parts, pipes and wires and cables.
PVC waste
PVC used to be the most used plastic in history, but now it is replaced by polyethylene and PET in some fields, but it is still widely used, and its consumption is second only to polyethylene and polypropylene. There are many forms of PVC products, which can be divided into three categories: hard PVC, soft PVC and PVC paste. Rigid PVC is mainly used for extruded products such as pipes, door and window profiles and sheets, as well as injection molded parts such as pipe joints and electrical parts and bottle products of extrusion blow molding, which account for more than 65% of the consumption of PVC. Soft PVC is mainly used in calendered sheets, automobile interior accessories, handbags, films, labels, wires and cables, medical products and so on. PVC paste accounts for about 1% of PVC products, and the main products are plastic-lined products.
polystyrene has a wide range of applications. It can be roughly divided into the following four aspects:
General polystyrene: a large number of products for daily use and transparent products such as household appliances, computers and medical care.
high-impact polystyrene: its impact strength and elongation at break are greatly improved, and its products are widely used in electrical accessories, household appliance shells, food containers and so on.
extruded expanded polystyrene sheets and their thermoformed products: thick sheets are mainly used as heat insulation, sound insulation and shock-proof materials. Thermoformed products are widely used in food packaging and fast food containers.
expandable polystyrene foam products: products are used for shock-proof packaging of electrical appliances and thermal insulation materials in construction, refrigeration and other industries.
the first two kinds of polystyrene products have long service life, and the waste thickness can be recovered by conventional recovery methods, so the pressure on the environment is also small. The latter two kinds of polystyrene products are mostly disposable packages, which are bulky and consume a lot. If they are discarded directly without treatment, it will cause great pressure on the environment. A large part of what people often say is "white pollution" is styrofoam.
polymethyl methacrylate, commonly called PMMA, has the advantages of high transparency, low price and easy machining, and is a commonly used glass substitute.
. What's the use of plexiglass?
plexiglass has a wide range of applications, and is suitable for aviation industry parts, environmental protection equipment, optoelectronic equipment parts, communication facilities, transportation facilities, mechanical parts, building models, medical facilities, teaching facilities, scientific research facilities, experimental facilities, decoration, handicrafts and many other fields.
. Plexiglass performance
Excellent transparency and outstanding aging resistance; Its specific gravity is less than half that of ordinary glass, but its shatter resistance is several times higher. It has good insulation and mechanical strength; Strong corrosion resistance to acid, alkali and salt; And is easy to process; It can be used for manual and mechanical processing such as bonding, sawing, planing, drilling, engraving, grinding, screen printing, sand blasting, etc. After heating, it can bend and die various products.
Physical properties of plexiglass:
Density: 1.19kg/cm 3 Light transmittance: 99% Impact strength ≥16kg/cm 3 Tensile strength ≥61Kg/m 3 Thermal deformation temperature ≥78℃ Thermal softening temperature ≥15℃.