Plastic is a monomer as raw material, through the addition or polycondensation reaction polymerization of polymer compounds, commonly known as plastic (plastics) or resin (resin), can be free to change the composition and body style, by the synthetic resin and filler, plasticizer , Stabilizers, lubricants, colorants and other additives.
First, polyethylene terephthalate (PET)
General mineral water, carbonated beverage bottles are made of polyethylene terephthalate (PET). In 1946 the United Kingdom published the first patent to prepare PET, 1949 British ICI formula to complete the pilot, but the United States DuPont purchased the patent, the establishment of the 1953 production plant, the world's first industrial production.
1, oil, fat, acid, dilute alkali, resistant to most solvents.
2, high transparency, light transmission rate can be as high as 90% or more, the packaging of goods have a good display function.
3, with excellent low temperature performance, resistant to -30 ℃ low temperature, in the range of -30 ℃ -60 ℃ use.
4, gas and water vapor permeability is low, both excellent gas barrier, water, oil and odor performance.
5, high transparency, can block ultraviolet, good gloss.
Precautions for use:
Beverage bottles can not be recycled with hot water, this material heat to 70 ℃, high temperature will be harmful substances dissolution, only suitable for heating or cold drink, installed high temperature liquid or heating is easy to deformation, there are substances harmful to the human body dissolution.
Second, polypropylene (PP)
Common PP commonly used in injection hanger, chairs, stools, barrels, pots, toys, stationery, office supplies, furniture, hinges, turnover boxes and so on. Modified PP for washing machine barrels, TV shell, fan blades, refrigerator lining, small appliances shell, and so on.
Polypropylene is a thermoplastic resin prepared by polymerizing propylene. According to the methyl position is divided into: ① isotactic polypropylene, ② random polypropylene and ③ syndiotactic polypropylene three.
PP non-toxic, tasteless, can be 100 ℃ in the boiling water immersion deformation, no damage, common acid, alkali organic solvent it almost does not work for utensils. Common soy milk bottles, yogurt bottles, fruit juice bottles , Microwave oven lunch box melting point up to 167 ℃, is the only microwave can be put into the plastic box, can be reused after careful cleaning.
PP preparation process
PP general use of injection molding: PP injection products can account for about half of daily necessities to ordinary PP as raw materials, auto parts to enhance or toughening PP as raw materials, other uses to high impact strength and low brittleness temperature PP-C raw materials The
Precautions for use
Some microwave lunch boxes, box body to the No. 5 PP manufacturing, but the lid is to No. 1 PE manufacturing, because PE can not withstand high temperatures, it can not be put together with the box into the microwave oven.
Third, polycarbonate (PC)
Mainly used in the glass assembly industry, the automotive industry and electronics, electrical industry, followed by industrial machinery parts, CD, packaging, computer and other office equipment, medical and health care, film, leisure and protective equipment.
Polycarbonate PC is a linear carbonated polyester in which the carbonic acid groups are alternately arranged with other groups, which may be aromatic, aliphatic or both. Currently used as engineering plastics are aromatic polycarbonate.
Precautions for use:
It is easy to release toxic substances bisphenol A, harmful to humans. Do not use the heat, do not direct sunlight in the sun.
Fourth, polyethylene (PE)
PE refers to the polymerization of ethylene monomer free radical polymer, the synthesis of raw materials from oil, rich in oil resources, its production since 1965 has been the highest first. The earliest industrialization of the varieties for the LDPE, in 1951 for the first time to achieve the scale of industrial production scale. At present, the main varieties of PE are LDPE, HDPE, LLDPE, UHMWPE and metallocene polyethylene. Membrane films commonly used in life are generally prepared from LDPE. Plastic pots, barrels of the material is generally HDPE.
Preparation of film is generally used to blow molding process:
Blown film method, a method of forming a thermoplastic film by extruding the plastic into a tube and then expanding it to a certain size of the tubular film by means of an air blown into the tube.
Preparation of pots and drums are generally made by injection molding process:
Injection molding machine using plastic heating to a certain temperature, can melt into the nature of the liquid, the molten liquid with high pressure injection into the closed cavity, after cooling stereotypes, open mold after the top to get the required plastic products.
Five, polyvinyl chloride (PVC)
PVC is a polymer made of free radical polymerization of polyethylene monomer. It is one of the earliest industrial varieties of resin. It is the largest resin variety before the 1960s, and only retreated in the second half of the 1960s.
According to the size of the molecular weight can be divided into general-purpose PVC (average polymerization degree of 500-1500) and high degree of polymerization (average degree of polymerization greater than 1700) two categories. Commonly used PVC resin for the general type.
The main performance of PVC:
1) General performance: PVC resin is a white or light yellow powder, the softness of its products can be added by adding the number of plasticizer parts, made of soft and hard phase difference between the products. Pure PVC water absorption and permeability are very small.
2) Mechanical properties: PVC has a high hardness and mechanical properties, and with the increase in molecular weight increases, but with the temperature rise. PVC in the plasticizer to join the different parts of the mechanical properties of a great impact, generally with the plasticizer content increases, decreased mechanical properties. PVC abrasion resistance in general.
1) the application of rigid PVC products
Pipe: for the water pipes, pipes, gas pipes, infusion pipes and threading pipe and other profiles: for doors, windows, decorative panels, wood lines, furniture and staircase handrails.
Plate: can be divided into corrugated board, dense board and foam board, etc., for the wall panels, ceilings, shutters, flooring and so on. Sheet: for plastic products, such as a variety of packaging and so on. Silk: for screens, mosquito nets, ropes and so on.
Bottle: food, medicine and cosmetics packaging materials.
Injection products: pipe fittings, valves, office supplies shell and electrical shell, and so on.
2) the application of soft PVC products
Film: agricultural greenhouse film, packaging film, raincoat film and so on.
Cable: for medium and low voltage insulation box sheathed cable material. Footwear: soles and noodles.
Leather: leather, floor leather and wallpaper. Other: soft transparent tube, record and gasket.