1, injection molding is also called injection molding.
2. Extrusion molding, also known as extrusion molding, is one of the main molding methods of thermoplastics.
3. Hollow molding is also called blow molding.
4. Compression molding is also called compression molding. Install the upper and lower molds between the upper and lower templates of the press, directly add the plastic raw materials into the cavity, close the molds, fill the cavity with plastic under heating and pressure, and cure and shape to obtain the plastic parts.
5. Pressure injection molding, also known as transfer molding, is also one of the main molding methods of thermosetting plastics. It puts plastic particles into the feed chamber of a mold, and the molten plastic fills the cavity through the gating system at the bottom of the feed chamber of the mold under heating and pressure, and then solidifies and forms.
6. Solid-phase molding makes plastics shape at melting temperature, and there is no obvious flow state during the molding process. It is mostly used for the secondary molding of plastic plates, such as vacuum molding, compressed air molding and pressure molding. At first, it was mostly used to form thin-walled parts, and it was first used to manufacture thick-walled parts.
7, other molding calendering, tape casting, rotational molding, foam molding, etc.
Question 2: What are the injection molding products? All products molded by injection molding machine are injection molded products. Including thermoplastics and some thermosetting injection products now.
The most remarkable feature of thermoplastic products is that raw materials can be injected repeatedly, but some physical and chemical properties of raw materials will be reduced.
The prospect of injection molding products is still relatively good. Injection molding products are used in various industries, such as automobiles, medical care and so on. Injection molding products have basically penetrated into various industries.
Question 3: What are the items of plastic products? According to the different use characteristics of famous plastics, plastics are usually divided into general plastics, engineering plastics and special plastics.
Plastics can be easily molded into different shapes according to their own characteristics. Widely used in all walks of life and all aspects of people's lives.
Question 4: What kinds of plastics are there? Plastic is a widely used synthetic polymer material, and plastic products can be found everywhere in our daily life. From the toiletries used after getting up, the tableware used for breakfast, to the stationery used for work and study, the cushion mattress used for rest, the casing of TV, washing machine and computer, and the lights of various shapes that bring us light at night. ...
With its excellent performance, plastics have gradually replaced many materials and utensils that have been used for decades and hundreds of years, and become an indispensable assistant in people's lives. Plastic combines the hardness of metal, the lightness of wood, the transparency of glass, the corrosion resistance of ceramics and the elasticity and toughness of rubber. Therefore, in addition to daily necessities, plastics are more widely used in aerospace, medical equipment, petrochemical, machinery manufacturing, national defense, construction and other industries.
I. Classification of plastics
There are many kinds of plastics, so far there are about 300 kinds of plastics put into production in the world. There are many ways to classify plastics, and there are two commonly used methods:
1, according to the different properties of plastics after heating, it can be divided into thermoplastic and thermosetting plastics.
The molecular structure of thermoplastics is linear, which softens or melts when heated, can be shaped into a certain shape, and then hardens after cooling. It becomes soft when heated to a certain extent, and becomes hard after cooling. This process can be repeated many times. Such as polyvinyl chloride, polyethylene, polystyrene, etc. Thermoplastic molding process is relatively simple, can be produced continuously, and has quite high mechanical strength, so it develops rapidly.
The molecular structure of thermosetting plastics is a kind of bulk structure, which can be softened by heating and shaped into a certain shape. However, after heating to a certain extent or adding a small amount of curing agent, it will harden and set, and will not soften and deform after reheating. Thermosetting plastics, such as phenolic plastics, amino plastics, epoxy resins, etc. Can't be recycled after processing and molding. Thermosetting plastics are complicated in molding process and difficult to produce continuously, but they are good in heat resistance, difficult to deform and relatively low in price.
2. According to the different uses of plastics, they can be divided into general plastics and engineering plastics.
General plastics refer to plastics with large output, low price and wide application range, mainly including polyolefin, polyvinyl chloride, polystyrene, phenolic plastics and aminoplastics. Many products used in people's daily life are made of these general plastics.
Engineering plastics can be used as engineering structural materials instead of metals to manufacture machine parts. Such as polyamide, polycarbonate, polyoxymethylene, ABS resin, polytetrafluoroethylene, polyester, polysulfone, polyimide and the like. Engineering plastics have the characteristics of low density, high chemical stability, good mechanical properties, excellent electrical insulation and easy processing and molding. , widely used in automobiles, electrical appliances, chemicals, machinery, instrumentation and other industries, as well as aerospace, rockets, missiles and so on.
Second, the composition of plastic
The plastic we usually use is not a pure substance, it is made of many materials. Polymer (or synthetic resin) is the main component of plastic. In addition, in order to improve the properties of plastics, various auxiliary materials, such as fillers, plasticizers, lubricants, stabilizers, colorants, etc. , must be added to the polymer to become a plastic with good performance.
1, synthetic resin
Synthetic resin is the most important component in plastics, and its content in plastics is generally 40% ~ 100%. Because of its large content and the nature of resin often determines the nature of plastic, people often regard resin as synonymous with plastic. For example, PVC resin and PVC plastic, phenolic resin and phenolic plastic are confused. In fact, resin and plastic are two different concepts. Resin is a kind of raw material polymer, which is not only used to make plastics, but also used as raw material for coatings, adhesives and synthetic fibers. Except a few plastics contain 100% resin, most plastics need to add other substances besides the main component resin.
Step 2 pack
Fillers, also called fillers, can improve the strength and heat resistance of plastics and reduce costs. For example, adding wood flour to phenolic resin can greatly reduce the cost, make phenolic plastic one of the cheapest plastics, and significantly improve the mechanical strength. Fillers can be divided into two categories: organic fillers, such as wood flour, rags, paper and various fabric fibers; Inorganic fillers, such as glass fiber, diatomite, asbestos and carbon black.
3. Plasticizer
Plasticizers can increase the plasticity and softness of plastics, reduce brittleness, and make plastics easy to process and shape. Plasticizer is usually miscible with resin, non-toxic, tasteless and light-sensitive. & gt
Question 5: Surface treatment of plastic products What are the surface treatments of plastic products?
IMD 1
2, oil spray processing, which metal paint is needed for paint.
3, surface bronzing treatment, (anodized transfer), but there are requirements for surface shape (also called thermal transfer)
(1). Regarding the material selection of hot stamping plates, that is, the indenter, the copper material is the best, because it has good heat dissipation and heat transfer, and is a neutral material among metals, neither too soft nor too hard, which is not only convenient to process, but also has certain elasticity and good durability. However, in practice, in order to reduce the material cost, many manufacturers choose aluminum alloy printing plates, which can save some money on the production cost of ironing plates. However, because aluminum is too soft and has a poor service life, it will take some time to make a new plate if the batch is large, and the plate-making cost is not cheap, so the material selection problem should be considered comprehensively.
(2) Hot stamping process conditions are easy to understand, that is, hot stamping pressure, hot stamping temperature and hot stamping time.
(3) The most important thing is the choice of bronzing materials, that is, bronzing paper, which should be matched with different bronzing substrates. Not a piece of hot stamping paper can cover all the materials, which is mainly related to the adhesion firmness during thermal transfer.
4. The general principle of water transfer printing is as follows: First, print the pattern to
On the transfer paper, the protective film is attached to the printed surface. Transfer paper is finished. When printing, the protective film must be torn off, soaked with water and pasted on the printed surface. Due to the action of water, ink adheres to the surface of the product. Then tear up the silver transfer paper. After the water is dry, the silver transfer is completed.
5. Vacuum lamination
6, surface drawing
7. Electroplating
Question 6: What are the plastic products? Plastic products are widely used, and the huge industry provides strong support for the development of China's plastic products industry. With the promulgation of "Detailed Planning Rules for Revitalizing Petrochemical Industry", the plastic products industry in China has ushered in new development opportunities. The market demand of plastic products in China is mainly concentrated in agricultural plastic products, packaging plastic products, building plastic products, industrial transportation and engineering plastic products.
Plastic products are made of different materials and have different uses. The numbers on the bottom of plastic bottles represent different materials.
The number "1" stands for polyethylene terephthalate, that is, PET. Mainly used in mineral water bottles, carbonic acid, fruit juice beverage bottles and soy sauce vinegar bottles. The heat-resistant temperature of PET bottles is 70 degrees Celsius, which is only suitable for warm or frozen drinks. After being filled with boiling water or heated, it is easy to deform, and substances harmful to human body will also be dissolved out.
The number "2" stands for high density polyethylene, namely HDPE. Composite membranes made of HDPE and other plastics are also used in aquatic products.
The number "3" stands for polyvinyl chloride (PVC). Because of its low price, it is also used to make intravenous infusion bags and disposable sterile infusion sets. However, if it is used for a long time, it will lead to the accumulation of harmful substance DEHP. Therefore, from the perspective of safety, it is the future trend for pharmaceutical industry to choose non-PVC materials.
The number "4" is low density polyethylene, namely LDPE. No.4 plastic is widely used in packaging. LDPE is mainly used to produce food preservative film and food plastic bag.
The number "5" is polypropylene, or PP. One is to make containers. PP is the only one that can be put in the microwave oven.
Plastic containers, or reusable plastic containers, can be used as storage containers to store food, oil and condiments. The second is packaging film, which has unstretched and biaxial stretching. Untretched polypropylene (CPP) is commonly used for
Packaging of snacks, bread, fruits, etc. ; Biaxially oriented polypropylene (BOPP) is a flexible packaging material comparable to cellophane.
The number "6" is polystyrene, or PS PS is mainly processed into film and foam in packaging. Film is used to package fruits and vegetables; Foamed plastics are mostly used in the bowls of instant noodle boxes and fast food boxes, but they are not resistant to high temperature and cannot be directly put into microwave ovens for heating, so as to avoid releasing toxic chemicals when the temperature is too high.
The number "7" is polycarbonate, that is, PC or other plastics. The plastic container made of PC may release toxic bisphenol A. The higher the temperature, the more it will be released and the faster it will be. So don't heat or directly expose to the sun when using.
Question 7: How many kinds of plastics are there? ABS: the common name of engineering plastics, which can be used for connectors, chair backs and seat boards. It is the main raw material for plastic electroplating (water electroplating).
PP: common name polypropylene, used for five-star feet, handrails, foot pads and connectors with low strength requirements. Disadvantages: poor wear resistance and low surface hardness.
PVC: commonly known as polyvinyl chloride, mainly used for edge sealing and insertion conditions. It is suitable for extrusion molding. At the same time, PVC material belongs to non-combustible materials in plastic parts, and its processing and molding temperature stability is poor, especially its color stability is not good.
PU: commonly known as polyurethane. Mainly used for handrail (foam) fittings.
POM: The common name is Sai Gang. Mainly used for wear-resistant parts such as foot pads, casters, door hinges, hinges and so on. Wear resistance and pressure resistance, but poor dimensional stability.
PA: commonly known as nylon. Mainly used as foot pads, five-star claws, casters and other places with wear resistance and high life requirements. Features: Wear resistance, pressure resistance, high strength and long indoor service life. Some models, such as PA66, are resistant to high temperature of 2200, but the disadvantages are variability, easy breakage and poor sun and weather resistance.
PMMA: plexiglass (commonly known as sub-afterburner). There are five transparent materials in plastics, and PMMA is the most transparent one. The workpiece smells of acetic acid when it is cut, and it is easy to deform when it is processed. Soaking in boiling water can shape and bend. Disadvantages: the surface is easy to scratch, the hardness is low, the bending is easy to crack, and the price is more than 20% higher than ABS.
PC: commonly known as polycarbonate. This variety is also a transparent material with high surface hardness, scratch resistance, strong impact resistance, high strength and good weather resistance (that is, not afraid of sunlight). Screen partitions and sun panels in furniture are made of this material by hollow extrusion. Features: high cost, about 40% higher than PMMA.
Question 8: What are the materials of common plastics? Related technologies and properties of common plastics.
(a) storage of ABS (acrylonitrile butadiene styrene * * * polymer
(2) PC (polycarbonate)
(III) Nylon 66
(4) polystyrene
(5) PVC
Question 9: What plastic inventions are common plastic products in life and can be called masterpieces of human beings in the 20th century? Plastic has undoubtedly become an indispensable and important raw material in modern civilized society. At present, plastics have been widely used in aviation, aerospace, communication engineering, computer, military, agriculture, light industry, food industry and other industries. Plastic, literally speaking, is a moldable material, that is, plastic material. Nowadays, plastic is a proper term for a kind of materials that are cast, extruded, blown or injected into molds by resin at a certain temperature and pressure. During the 65438+60s, due to the shortage of ivory in the United States, there was a lack of raw materials for making billiards. The earliest artificial plastic celluloid was patented in 1869. Although celluloid is the earliest artificial plastic, it is an artificial plastic, not a synthetic plastic. The first synthetic plastic was made of phenolic resin by pressing with a heating mold. It was made by Backlander, an American Belgian chemist of 19 10 in the early 20th century. Backlander used sawdust to heat and pressurize phenolic resin to make various products, which were named bakelite after his surname, and we called it bakelite. After the First World War, the radio, radio and other electrical appliances industries developed rapidly, increasing the demand for bakelite, which has been used ever since. In the chemical industry, instruments that don't need acid to work were once made of special steel, which was very expensive. It is much cheaper to replace them with alkali-resistant bakelite. But bakelite is not alkali-tolerant. It is a good material for making buttons and chess pieces. Some parts of tractors and cars are also made of it. Austrian chemist John made urea-formaldehyde resin. The plastic made of it is colorless, light-resistant, high in hardness, high in strength, non-flammable and light-permeable, also called electric jade. In the 1920s, it was used as a glass substitute in Europe. In 1930s, melamine formaldehyde resin appeared again, which was made of urea. Melamine formaldehyde resin can be used to make arc-resistant materials, which are fire-resistant, waterproof and oil-resistant. Since then, plastics such as polyethylene, polyvinyl chloride, polystyrene and plexiglass have appeared one after another. I have to say that bakelite opened the door. The 20th century is the century of plastics. Looking back on the 100-year history of plastics and looking forward to the 2 1 century, with the emergence and development of high-speed computers, information and network technologies, new energy, aerospace technology, life sciences and other cutting-edge technologies, human society will surely undergo further changes, and the space for human activities in the sky and the earth will also be further expanded, while nano-plastics, optical fibers, conductive plastics, magnetic plastics, memory plastics, etc. will also be further developed. It is believed that the human history of Paleolithic Age, Neolithic Age, Pottery Age, Bronze Age and Iron Age has accelerated the improvement of civilization because of plastics. Although people have been exclaiming the arrival of the plastic age in the past century, perhaps the new century is the real arrival of the plastic age, and the past century is only a prelude to the plastic age.