Uses of waste plastics and recycled plastics

EPS foam is a thermoplastic material, containing 3-6 million independent closed air bubbles per cubic meter of volume, containing more than 98% of the volume of air, because the thermal conductivity of air is very small, and is enclosed in the foam and can not be convective, so EPS is a very good thermal insulation and thermal performance of the material.

First, the definition of plastic plastic is a resin as the main component, at a certain temperature and pressure molded into a certain shape, and at room temperature can maintain the established shape of polymer organic materials. Resin is usually transformed or molten range when heated, transformed by external forces with liquidity, at room temperature is a solid or semi-solid or liquid organic polymers, it is the most basic, but also the most important components of plastics. Broadly speaking, in the plastics industry as the basic material of any polymer can be called resin.

Second, the classification of plastic plastic is not yet exact classification, the general classification is as follows: 1. According to the physical and chemical properties of plastics thermoplastics: in a specific temperature range can be repeatedly heated softening and cooling hardening of plastics. Such as polyethylene plastic, polyvinyl chloride plastic. Thermosetting plastics: due to heat or other conditions can be cured into a non-melting insoluble material plastic. Such as phenolic plastics, epoxy plastics, etc. 2. According to the choice of plastics, general-purpose plastics: generally refers to the production, wide range of uses, good molding, inexpensive plastics. Such as polyethylene, polypropylene, polyvinyl chloride, etc. Engineering plastics: generally refers to be able to withstand certain external forces, and has good mechanical properties and dimensional stability, in high and low temperatures can still maintain its excellent performance, can be used as engineering structural parts of the plastic. Such as ABS, nylon, poly alum, etc. Special plastics: generally refers to special features (such as heat-resistant, self-lubricating, etc.), applied to the special requirements of the plastic. Such as fluoroplastics, silicones, etc. 3. according to the plastic molding method of molding plastics: for the molding of resin mixture. Such as general thermosetting plastics. Laminated plastics: refers to the resin-impregnated fiber fabric, can be laminated, hot pressed together and become a whole material. Injection, extrusion and blow molding plastics: generally refers to resin mixes that can melt and flow at the barrel temperature and harden rapidly in the mold. Such as general thermoplastics. Casting plastics: Liquid resin mix that can be poured into the mold under no pressure or slightly pressurized and can harden into a certain shape product. Such as MC nylon. Reaction injection molding plastic: generally refers to the liquid raw material, injected into the mold cavity under pressure, so that it reacts and cures to make finished products. Such as polyurethane class. 4. According to the plastic semi-products and products into molding powder: also known as plastic powder, mainly from thermosetting resins (such as phenolic) and fillers, etc. by fully mixed, pressed, crushed and obtained. Such as phenolic plastic powder. Reinforced plastics: with reinforcing materials and certain mechanical properties than the original resin has a greater increase in a class of plastics. Foam: Plastic with numerous micro-pores inside the whole. Film: generally refers to the thickness of O.25 mm or less flat and soft plastic products.

Third, the basic properties of plastics 1. light weight, high strength. Plastic is light, the general density of plastic are between 0.9 to 2.3 g / cm3, only 1/8 to 1/4 of steel, aluminum 1/2 or so, and a variety of foam density is even lower, about 0.01 to O.5 g / cm3 between. The strength per unit mass is called the specific strength, and some reinforced plastics are close to or even exceed the strength of steel. For example, alloy steel, its tensile strength per unit mass of 160 MPa, while the glass fiber reinforced plastic can reach 170 ~ 400 MPa. 2. Excellent electrical insulation properties. Almost all plastics have excellent electrical insulation properties, such as very small dielectric loss and excellent arc resistance characteristics, these properties are comparable to ceramics. 3. excellent chemical stability performance. General plastics have good corrosion resistance to acids and bases and other chemicals, especially polytetrafluoroethylene chemical corrosion resistance is better than gold, and even resistant to “aqua regia” and other strong corrosive electrolyte corrosion, known as “plastic king”. 4. friction reduction, good wear resistance. Most plastics have excellent friction reduction, wear resistance and self-lubricating properties. Many engineering plastics manufacturing friction-resistant parts is the use of these characteristics of plastics, wear-resistant plastics in the addition of certain solid lubricants and fillers, can reduce its friction coefficient or further improve its wear resistance. 5. light transmission and protective properties. Most plastics can be used as transparent or translucent products, including polystyrene and acrylate plastics as transparent as glass. Plexiglass chemical name for polymethyl methacrylate, can be used as aviation glass materials. Polyvinyl chloride, polyethylene, polypropylene and other plastic films have good light transmission and warmth properties, and are used in large quantities as agricultural films. Plastic has a variety of protective properties, so often used as protective protective supplies, such as plastic film, boxes, barrels, bottles, etc. 6. shock absorption, excellent sound-deadening properties. Some plastics are flexible and elastic, when it is subject to frequent mechanical shocks and vibrations, internal viscous internal consumption, mechanical energy into heat, therefore, the engineering used as shock-absorbing and sound-deadening materials. For example, bearings and teeth made of engineering plastics can reduce noise, and various kinds of foam are widely used as excellent shock-absorbing and sound-deadening materials. The above-mentioned excellent performance of plastics makes it widely used in industrial and agricultural production and people’s daily life; it has become an indispensable material for modern life and cutting-edge industry from the past as a substitute for metal, glass, ceramics, wood and fiber. However, plastics also have shortcomings. For example, heat resistance is worse than metals and other materials, generally plastic can only be used at temperatures below 100 ℃, a few 200 ℃ or so; plastic coefficient of thermal expansion is 3 to 10 times greater than that of metals, easily affected by temperature changes in size stability; under load, plastic will slowly produce viscous flow or deformation, that is, creep phenomenon; in addition, plastic in the atmosphere, sunlight, long-term pressure or some quality In addition, plastics in the atmosphere, sunlight, long-term pressure or some quality under the action of aging, so that performance deterioration. These disadvantages of plastic more or less affect or limit its application. However, with the development of the plastics industry and plastic materials research work, these shortcomings are gradually overcome, with excellent performance of novel plastics and a variety of plastic composites are emerging.

Fourth, the use of plastic plastic has been widely used in agriculture, industry, construction, packaging, defense, cutting-edge industry and people’s daily lives and other fields. Agriculture: a large number of plastics are used in the manufacture of ground film, seedling film, greenhouse film and drainage and irrigation pipes, fish nets, breeding floats, etc. In industry: Electric and electric industries widely use plastics to make insulating materials and encapsulation materials; in the machinery industry, plastics are used to make transmission gears, bearings, tiles and many parts instead of metal products; in the chemical industry, plastics are used as pipes, various containers and other anti-corrosion materials; in the construction industry, they are used as doors and windows, stair handrails, floor tiles, ceilings, heat and sound insulation panels, wallpapers, drainage fittings and pit pipes, decorative panels and sanitary ware. decorative panels and sanitary ware, etc. In the national defense industry and cutting-edge technology, whether it is conventional weapons, aircraft, ships, or rockets, missiles, artificial satellites, spacecraft and atomic energy industry, plastic is an indispensable material. In people’s daily life, plastics are more widely used, such as plastic sandals, slippers, raincoats, handbags, children’s toys, toothbrushes, soap boxes, hot water bottle shells, etc. sold in the market. At present, it is also widely used in various household appliances, such as TV sets, recorders, electric fans, washing machines, refrigerators, etc. As a new packaging material, plastic has been widely used in the packaging field, such as a variety of hollow containers, injection containers (crates, containers, barrels, etc.), packaging films, woven bags, corrugated boxes, foam, strapping rope and packing tape, etc.

In 1868, natural cellulose was nitrated and camphor was used as a plasticizer to make the world’s first plastic, called celluloid, which began the history of plastic use. The first synthetic plastic, phenolic plastic, appeared in 1909, and another synthetic plastic, amino plastic (aniline formaldehyde plastic), was born in 1920. These two plastics then played an active role in promoting the development of the electrical industry and instrument manufacturing industry. By the 1920s and 1930s, alkyd resins, polyvinyl chloride, acrylates, polystyrene, polyamide and other plastics appeared one after another. From the 1940s to the present, with the development of science and technology and industry, and the extensive exploitation of petroleum resources, the plastics industry has been developing rapidly. Varieties of polyethylene, polypropylene, unsaturated polyester, fluoroplastics, epoxy resins, polyformaldehyde, polycarbonate, polyimide and so on. Scrap plastic basic knowledge Q & A 1. What is PPC type plastic and how to identify it from the appearance? Answer: PPC belongs to the PP category, known as chlorinated polypropylene, used in the manufacture of daily necessities, electrical appliances, etc. 2、What type of raw materials are used for the production of HDPE gas pipes and water pipes? Reply: The raw materials used to produce HDPE gas pipes and water pipes are PE80 and PE100. 4、What kind of material is PPN? Answer: PPN is a kind of polypropylene.3、What is this plastic PPU? Reply: PPU is thermoplastic polyurethane. 4、How can we identify PVC plastic and can PVC be regenerated and granulated? What is the way to do it? Answer: 1) PVC: polyvinyl chloride. Burning method of identification, softening or melting temperature range: 75 ~ 90 ° C; burning situation: difficult to soften; burning flame state: yellow on the green with smoke; after the fire situation: off the fire extinguished; smell: irritating acidic smell. Solvent treatment identification, solvent: tetrahydrofuran, cyclohexanone, methyl ketone, dimethylformamide; non-solvent: methanol, acetone, heptane. 2) can be regenerated granulation. 3) PVC recycling process mainly includes the following six steps: (1) pretreatment of PVC waste; (2) selective dissolution in mixed solvents; (3) separation of insoluble substances; (4) regeneration of PVC precipitation; (5 ) drying process; (6) recovery and recycling of solvents 5, what is the use of ethylene propylene rubber? Reply: Ethylene propylene rubber has ternary and binary ethylene propylene rubber, general use: all molded products; general-purpose hose and heat-resistant hose in the car; manufacturing electrical components; because of the excellent extrusion performance, can be blended with high-viscosity rubber to improve its extrudability. 6, what is the material used to make the beverage bottle cap? Reply: It is generally made of PP (polypropylene). 8、Does 5000S raw material belong to linear plastic? Answer: 5000S is HDPE (high density polyethylene), not a linear plastic. 9、Looking for a plastic that can withstand high temperature. About more than 200 degrees. Answer: PTFE can meet the above requirements. In addition, high temperature resistant special engineering plastics are fluorine plastic silicone resin polyetherimide polyetheretherketone liquid crystal polymer. Modified nylon can withstand high temperatures above 250 degrees. 10、Does ABS belong to the modified polystyrene category? Answer: ABS is acrylonitrile-butadiene-styrene copolymer, does not belong to modified polystyrene class, modified polystyrene belongs to PS. 11、What is the difference between high-pressure polyethylene and low-pressure polyethylene? Reply: High-pressure polyethylene (HPPE) is low-density polyethylene (LDPE); low-pressure polyethylene (LPPE) is high-density polyethylene (HDPE).12、I want to regenerate plastic pellet plant, but I do not know what material those woven bags belong to, such as PP, ABS, etc.. Reply: PP is generally used to make woven bags; ABS is more rigid and is generally used to make shells, parts, etc. 13、What is the specific gravity of ABS? Response: ABS density is around 1.05 grams per cubic centimeter, slightly heavier than water, and has the characteristics of toughness, hardness, and rigidity. 14、What type of plastic are MSRESIN, ATRATE, and TYPE, what are their names, and what are their products? Reply: MSRESIN for MS resin, is a commonly used transparent plastic materials, general injection molding and extrusion molding, transparency is close to PMMA, used for optical components / toys / lampshades / OA accessories / food containers / household appliances / building materials, etc.; 15, what is the English code for waste acrylic. Reply: Acrylic (ACRYLIC) is a special organic glass. PMMA is commonly known as organic glass, also known as acrylic or acrylic, Hong Kong people more called ACRYLIC, is an important thermoplastic developed earlier, with good transparency, chemical stability and weather resistance, easy to dye, easy processing, beautiful appearance, has a wide range of applications in the construction industry. 16, PS material and ABS material performance The difference between PS and ABS? Reply: PS plastic (polystyrene), material performance: electrical insulation (especially high-frequency insulation) excellent, colorless and transparent, light transmission rate second only to organic glass, coloring water resistance, chemical stability is good,. General strength, but brittle, easy to produce stress brittle crack, not resistant to benzene. Gasoline and other organic solvents. Suitable for making insulating transparent parts. Decorative parts and chemical instruments. Optical instruments and other parts. Molding performance: 1. Amorphous material, small moisture absorption, do not need to fully dry, not easy to decompose, but the coefficient of thermal expansion is large, easy to produce internal stress. Good flowability, available screw or plunger injection molding machine. 2. 3. Various forms of gates are available, and the gates are connected with the plastic arc to avoid damage to the plastic parts when going to the gates. The slope of demoulding is large, and the ejection is even. ABS (acrylonitrile-butadiene-styrene), a shallow *** granular or pearly opaque resin, non-toxic, tasteless, low water absorption. ABS has excellent physical and mechanical properties, excellent low temperature impact resistance, excellent electrical properties, wear resistance, dimensional stability, chemical resistance, dyeing. ABS is resistant to water, inorganic salts, alkalis and acids, insoluble in most alcohols and hydrocarbon solvents, easily soluble in aldehydes, ketones, esters and some chlorinated hydrocarbons. the disadvantages of ABS are combustibility, low heat deflection temperature and poor weather resistance. Combustion characteristics: flammable; continues to burn away from the fire; flame ***, thick black smoke; softening, blistering; acrylonitrile taste. Solubility: soluble solvent: methylene chloride; insoluble solvent: alcohols, aliphatic hydrocarbons, water. Applications: automotive industry, machinery and equipment, electronic appliances, etc. 17、What PP material is used in syringes? Can it be recycled? Reply: The PP material used for syringes is a kind of random copolymer PP, which can be recycled, and it is strongly recommended not to use recycled material, because it is easy to cause medical accidents. 18、Waste PET use, processing technology? Reply: Uses: Recycled pet is mainly used for fibers, flakes, non-food packaging bottles, etc. Developed uses include: construction materials, food packaging and containers, etc. Japanese companies have used polymer alloy improvement technology to process recycled pet into powder coatings with better performance than those made from new pet materials. Processing process: Japanese company Teijin has developed a recycling method of DMT (dimethyl terephthalate) and EG (ethylene glycol) from waste PET bottles. The waste PET bottles are first crushed and cleaned, then dissolved in EG, and the PET is depolymerized at the boiling temperature of EG and under the pressure of 0.1MPa to produce bis-mono hydroxyethyl terephthalate (BHET). After filtering and removing the filter residue and additives, the BHET reacts with methanol and under the boiling temperature of methanol and pressure of 0.1 MPa, the ester exchange reaction produces DMT and EG. After distillation, the DMT and EG are separated, and then the DMT is refined through a recrystallization process; the EG is purified through distillation, and the methanol can be recycled. The recovered DMT and EG are both 99.99% pure and the production cost is comparable to that of the common DMT and EG method. DMT can be converted into pure TPA (terephthalic acid), which is used to make bottle grade PET resin. The recycling unit can generate about 10% of the company’s raw materials for resin production.19、How are waste plastics classified? Reply: Commonly used waste plastics are broadly divided into PE, PP, PVC, PET, EPS, ABS, PA, etc.; among them, PE has plastic shed material, industrial packaging film, lactic acid beverage bottles, detergent bottles, etc.; PP has woven bags, packing tape, bundling rope, some car bumpers, etc., PVC has plastic door and window profiles, pipes, etc.; PET has Coke, Sprite and other tea beverage bottles; EPS is commonly known as 20, the chemical name of waste plastics, and various waste plastics into pellets can be made into what plastic products. For example, what can be made from mineral water bottles after making pellets? Its chemical name? What can be made of woven bags into pellets? Reply: Thermoplastic manufactured products can be recycled and then granulated, called recycled plastic, and its name is **recycled material. Theoretically, its use is slightly narrower than new material. Because of the level of recycling technology and the special nature of the finished product: such as food packaging, medical treatment, etc. (to avoid harm to the human body, generally such products do not use recycled material). However, the advanced recycling technology and strict recycling system in developed countries have made the performance of recycled materials close to that of new materials, even through the sex, synthesis and other new uses can be developed. Domestic technology is backward, and so far, recycled plastic pellets have not introduced corporate standards or national standards. Therefore, the quality of plastic recycled material varies, and its use depends on its specific technical indicators. 21, organic plastic (acrylic) What is the English code? Reply: Acrylic (ACRYLIC) is a special kind of organic glass, PMMA for short 26, what is the scientific name of nylon? Answer: nylon is also known as PA or polyamide. 22, the kind of infusion tube used in hospitals is made of what kind of plastic? Answer: PVC,PE28、Detailed use of polytetrafluoroethylene? Reply: Polytetrafluoroethylene (PTFE), commonly known as King of Plastics, is the largest production and use of fluoroplastics species, accounting for about 70% of the entire production of fluoroplastics, used in chemical, mechanical, electrical, construction, electronics, automotive and many other fields 23, please ask the information about PPR? Aluminum-plastic PPR composite pipe and stainless steel PPR composite pipe. Reply: PPR pipes are used in industrial and civil buildings for domestic and sanitary drinking water supply and hot water heating systems, and are upgraded products to replace copper and galvanized pipes, and can be used for: 1 residential hot and cold water systems 2 water purification and pure water pipelines 3 industrial water and chemical substances transport and discharge 4 hot water circulation systems 5 compressed air pipes 6 food and beverage production transport systems 7 other industrial and agricultural pipes. Steel-plastic composite pipe is an ideal environmentally friendly pipe widely used in urban construction water supply, natural gas, petrochemical industry and other fields. Steel-plastic composite pipe has the double advantages of metal and plastic; high temperature and pressure resistance, corrosion resistance; smooth inner wall, low resistance, no scale, non-toxic, non-pollution, anti-static, heat insulation, easy to cut, processing. Aluminum-plastic composite pipe application range: industry: various instruments, instrumentation shielding conduit, insulation conduit, various gases, liquid media transmission pipeline. Construction industry: building indoor cold, hot water, gas conduit, solar water heater cold and hot pipes, low temperature radiation, heating pipes. Agriculture: nursery, orchard, garden sprinkler irrigation pipes and other irrigation engineering pipes. Public utilities: hotels, restaurants, cold and hot water piping, hospital oxygen piping, food delivery piping, a variety of air conditioners with pipes, a variety of piping on ships. 24、What is the plastic used for springs? Reply: The main spring plastic performance requirements: 1, deformation energy V value to be large (that is, the spring modulus E value to be small) 2, strength, especially fatigue strength to be large 3, easy processing molding thermoset fiber-reinforced plastic (FRP) deformation energy V value than the general metal are large, compared with spring steel; and its high strength, stress is a one-way distribution, is the ideal material for the manufacture of leaf springs. 25, ABS.PS.PP. PE and other materials characteristics of the main uses and the difference between each grade. Reply: ABS has good rigidity, high impact strength, heat resistance, low temperature resistance, chemical resistance, excellent mechanical strength and electrical properties, easy processing, processing dimensional stability and good surface gloss, easy to paint, coloring, but also can be sprayed metal, electroplating, welding and bonding and other secondary processing properties. Main applications: automotive, appliances, electronics / electrical appliances, building materials, ABS alloys / blends PS electrical insulation (especially high-frequency insulation) excellent, colorless and transparent, light transmission rate second only to Plexiglas, coloring water resistance, good chemical stability,. General strength, but brittle, easy to produce stress brittle crack, not resistant to benzene. Gasoline and other organic solvents. Suitable for making insulating transparent parts. Decorative parts and chemical instruments. PE is basically divided into three categories, namely high-pressure low-density polyethylene (LDPE), high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE). Film is its main processed product, followed by sheet and coating, bottles, cans, barrels and other hollow containers and other kinds of injection and blow molding products, pipes and insulation and sheathing for wires and cables. It is mainly used in the packaging, agriculture and transportation sectors. pp is cheap, light, good processability and versatile, and the development of catalysts and new processes has further contributed to the expansion of applications, and it has been said that “as long as there is a product whose material is replaced by plastic, then that product has the potential to use polypropylene”. Main uses: woven bags, tarpaulins, consumer durables: such as automobiles, home appliances and carpets, etc. 26, PC commonly used products are those kinds of, VCD discs and outer packaging box is what plastic made? Answer: polycarbonate (PC) materials have the advantages of light weight, transparency, high strength, shock resistance and good processing performance, in the development of more than 50 years, the application areas continue to expand. PC products have been penetrated into the automotive, construction, medical, clothing and other industries, PC lights, PC car sunroof, automotive communication systems in the light wave transmitter fiber, transparent roof, PC sheet, PC In addition, the bottom of the swimming pool since the lighting system, solar energy collection system, high-definition large TV screens, textiles can be identified in the fabric material chip marker fiber and some other brand-new areas are PC materials, PC products are contributing to all walks of life, and its application potential will be further developed. Optical disc is the most familiar PC application area, and it is developing towards large capacity, the new DVD storage capacity is expected to reach 100 billion bytes. 27, pc performance reply: high impact strength, size stability model, colorless and transparent, good coloring, electrical insulation, corrosion resistance, good wear resistance, but poor nuisance lubrication, the tendency of stress cracking, high temperature easy hydrolysis, and other resin 28、ACETAL (acetal diacetal) is commonly known as what material? What is the performance? Reply: ACETAL is acetal, acetal diethanol; commonly known as plastic steel (Hong Kong and Taiwan are called: plastic steel); available for outdoor products such as buckles, high hardness, moisture resistance, can be used in a cold or dry environment.

29、What are the plastic materials that do not deform in 180 degrees? Answer: Aromatic nylon can reach 260℃, and fluoroplastics can withstand such high temperatures. 30、Is PP powder a universal material? Is it as common as drawing for injection molding? Can it replace PP material? Reply: PP plastic is a general-purpose plastic. As long as the equipment allows, powder and granules can replace each other.31、May I ask how the daily oil prices of Brent, WTI and OPEC are analyzed, and how the futures of oil are high or low to see whether the plastic trend is high or low now and later? Answer: by the role of the cost-push principle: crude oil – naphtha – ethylene – polyethylene – plastic products, crude oil prices and plastics are consistent with the general trend (short-term divergence is also very normal), but this impact should theoretically have a certain lag effect, and does not react so sensitively as other plastics markets currently do.