Foam is a large number of gas microporous dispersion in the solid plastic and the formation of a class of polymer materials, lightweight, heat insulation, sound absorption, shock absorption and other characteristics, and dielectric properties better than the base resin, a wide range of uses. Almost all kinds of plastic can be made into foam, foam molding has become an important area of plastic processing.
Foam and pure plastic, compared with low density, light weight, high specific strength, its strength increases with density, the ability to absorb shock loads, excellent buffer damping performance, sound absorption performance, low thermal conductivity, good thermal insulation, excellent electrical insulation properties, corrosion resistance, mold resistance. Flexible foam with excellent elasticity and other properties.
Advantages of foam
(1) very low weight, can reduce the weight of packaging, reduce transportation costs;
(2) has an excellent shock, vibration energy absorption, used to cushion anti-vibration packaging can greatly reduce the product breakage;
(3) temperature, humidity changes in the adaptability to meet the general requirements of the packaging situation;
(4) water absorption, sound absorption, excellent electrical insulation properties, corrosion resistance, mold resistance.(4) low water absorption, hygroscopicity is small, good chemical stability, itself will not produce corrosion of the contents, and acid, alkali and other chemicals have a strong resistance;
(5) low thermal conductivity, can be used for thermal insulation packaging, such as ice cream cups, fast food containers and thermal insulation of fish tanks, etc.;
(6) easy to form and process, you can use molding, extrusion, injection molding methods, such as Made of a variety of foam cushions, foam blocks, sheets and so on. Easy to secondary molding process, such as foam sheets can be made into a variety of fast food containers by thermoforming. In addition, the foam block can also be used for adhesive bonding or bonding with other materials, made of a variety of cushioning pads.
Question 2: What are the raw materials of foam, how to make it 1, epoxy resin
Bisphenol A-type epoxy resin is mostly used, epoxy value of 0.51 ~ 0.22 mol/100g. Viscosity 25 ℃ for 20Pa?s; 130 ℃ viscosity 1Pa?s.
2, curing agent
Epoxy resin can be used. Curing agent of various kinds of epoxy resin.
3, foaming agent
Epoxy resin foaming agent with physical foaming agent and chemical foaming agent two categories. Physical blowing agent is mainly low boiling point liquid, such as trichlorofluoromethane (F11), trichlorotrifluoroethane (F112), dichlorodifluoromethane (F12) and so on. The curing heat of epoxy resin is used to make the low-boiling liquid evaporate, release gas and foam, and the resulting product has low density and low thermal conductivity. However, fluorine-containing hydrocarbons have a destructive effect on the atmospheric environment and are usually used in spray foaming process. According to China Epoxy Resin Industry Association experts, toluene and other auxiliary foaming agent. In addition to foaming, but also play the role of curing reaction heat absorber and diluent.
Chemical blowing agent is mainly azo organic compounds, such as azodicarbonamide (ADCA or AC), 2,2'-azobisisobutyronitrile (AIBN) diazo aminobenzene (DAB) and so on. This foaming agent is cheap and the decomposition products are non-toxic, odorless and colorless. In addition, there are sulfonyl hydrazides, such as 4,4'-oxo-bis-benzenesulfonyl hydrazide (OBSH) and so on. When selecting, attention should be paid to the decomposition temperature. The properties of commonly used chemical blowing agents are summarized as follows:
Azodicarbonamide (AC, ADCA). Orange crystalline powder. 120 ℃ above the decomposition of a large number of gases (N2, CO and a small amount of CO2), the standard state of the amount of gas 200 ~ 300mL / g, as a high-efficiency blowing agent.
2,2'-Azobisisobutyronitrile (AIBN, AZDN, ABN), white crystalline powder, decomposition at 98-110 ℃ to release N2, gas generation (standard state) 130-150mL/g. Slow decomposition at room temperature, should be stored below 10 ℃.
4,4'-Oxybisbenzenesulfonylhydrazide (OBSH). White or light yellow crystalline powder. Decomposes in resin at 120-140C to release N2 and water vapor. The amount of gas emission is about 120 mL/g. It does not decompose below 100℃ and has good processing safety. Sodium bicarbonate can activate it and reduce the decomposition temperature. Bubble structure is fine and uniform.
4, surfactant (foam stabilizer)
Can reduce the surface tension of the liquid, conducive to the stabilization of foam bubble hole uniformity. Epoxy resin foam with surfactants: polyoxyethylene sorbitan laurate (Tween 20), polydimethylsiloxane-polyolefin oxide **** polymer, ethylene oxide - propylene oxide block **** polymer (L-64).
5, filler
Adding filler can reduce costs, reduce curing exothermic peak strength and shrinkage, improve the apparent quality, improve chemical resistance. Commonly used talc, quartz powder, hollow microspheres and so on. However, talc and quartz powder will make the density of the foam increase and mechanical properties decrease. Hollow microspheres with very small loose density are an ideal filler. Divided into two categories of organic materials and inorganic materials. Inorganic microspheres such as glass hollow microspheres, ceramic hollow microspheres; organic microspheres such as phenolic hollow microspheres, urea-formaldehyde solid microspheres, and disposable polystyrene particles. Generally speaking, inorganic microspheres are more effective as fillers for epoxy foam. It can improve the strength, heat resistance, dimensional stability and surface smoothness of the foam. In the foam curing process will occur in the microsphere floating phenomenon, so need to add the appropriate amount of thixotropic agent.
6, thixotropic agent
Commonly used thixotropic agents are bentonite, diatomaceous earth, asbestos, mica, organic complexes, metal soap powder and solid vegetable oils, etc., which can stabilize the position of the foam and microspheres to prevent floating and delamination.
Question 3: What is the material of the foam box Polyurethane foam, code: R141B
Question 4: What is the material of the PU foam PU foam material is polyurethane.
Polyurethane: short for polyurethane material, the English name is polyurethane, it is a polymer material. Polyurethane is an emerging organic polymer materials, known as the "fifth largest plastic", because of its excellent performance and is widely used in many areas of the national economy. It is widely used in many fields of national economy because of its excellent performance. The application fields of the products involve light industry, chemical industry, electronics, textile, medical treatment, construction, building materials, automobile, national defense, aerospace, aviation and so on.
1. Flexible PU
Cushioning material - such as seats, sofas, mattresses, etc., polyurethane foam is a very ideal cushioning material, cushioning material is also the largest amount of flexible foam applications;
Sound-absorbing materials - open-cell polyurethane foam, such as seats, sofas and mattresses. -Open cell polyurethane flexible foam has good sound absorption and shock absorption function, can be used as indoor sound insulation materials;
Fabric composite materials - shoulder pads, bra sponge, cosmetic cotton; toys.
2. Rigid PU
Refrigeration equipment - such as refrigerators, freezers, cold storage, refrigerated trucks, etc., polyurethane rigid foam is the most ideal insulation material for refrigeration equipment;
Industrial equipment insulation - such as storage tanks, pipelines, etc.;
The industrial equipment heat preservation.
Construction materials - in developed countries in Europe and the United States, polyurethane rigid foam for construction accounted for about 70% of the total consumption of rigid foam, which is more than double the amount of rigid foam used for refrigerators, freezers, etc.; in China, the application of rigid foam in the construction industry is not as common as that of the developed countries in the West, so the development potential is very high. In China, the application of rigid foam in the construction industry is not as common as in developed countries in the West, so the potential for development is very large;
Transportation - such as automobile headliners, interior parts (steering wheel, dashboard), etc.;
Imitation of wood - high-density (density of 300-700kg/m3) polyurethane rigid foam or glass fiber reinforced rigid foam Rigid foam or glass fiber reinforced rigid foam is a structural foam, also known as wood-like, with high strength, good toughness, dense and tough crust, simple molding process, high production efficiency, high strength can be compared to natural wood, density can be compared to natural wood is low, can be used as a substitute for wood as various types of high-grade products.
The material - such as waterproof grouting materials, leakage plugging materials, roof waterproofing materials;
Flower industry - PU flower pots, flower arrangement mud. PU Semi-rigid PU
Energy-absorbing foam body - energy-absorbing foam body has excellent shock absorption, cushioning performance, good resistance to compression load performance and deformation recovery performance, and its most typical application is used in the preparation of automobile bumpers;
Integral Skin Foam (Integral Skin Foam). Integral Skin Foam) - used in the preparation of automotive steering wheel, armrests, headrests and other soft internal functional parts and interior trim. Integral Skin Foam products are typically processed using Reaction InjectionMoulding (RIM);
Microcellular Elastomers - The most typical application for polyurethane microcellular elastomers is in the shoe industry.
Question 5: What is the foam packaging material Foam packaging is divided into many kinds of commonly used EPS foam, the price is low, there is EPP, can be recycled and reused, and EPO, etc., and the usual foaming also have EPP single-layer multi-layer;
Question 6: Foam is made of what material Foam is a chemical material, the full name of the polystyrene foam ( Expanded Polystyrene, referred to as RIM) processing technology;
Microcellular elastomers - Polyurethane microporous elastomers most typical applications are used in the shoe industry. Expanded Polystyrene, referred to as EPS)
Because of its lightweight, strong, shock-absorbing, low moisture absorption, easy to mold and good water resistance, insulation, low price and other characteristics, is widely used in packaging, thermal insulation, waterproofing, heat insulation, shock absorption and other fields, is one of the most widely used plastics in the world today. It can be applied to the shockproof packaging of electrical appliances, instruments, crafts and other fragile valuables as well as the packaging of fast food.
Question 7: What kind of plastic is used to make the foam can be a variety of plastics, foamed polyethylene, foamed polystyrene, foamed polyurethane and so on.
Question 8: How to take the Harvard High school English must pass the University 6, so that there is capital
Question 9: What is the foam made of The foam you are talking about should refer to Styrofoam.
Foam is a class of polymer materials formed by a large number of gas microporous dispersion in the solid plastic, with light weight, heat insulation, sound absorption, shock absorption and other characteristics. Almost all kinds of plastic can be made into foam.
Question 10: What materials to make bubbles? 1, epoxy resin, bisphenol A-type epoxy resin, epoxy value of 0.51 ~ 0.22mol/100g. Viscosity 25 ℃ for 20Pa?s; 130 ℃ viscosity of 1Pa?s. 2, curing agent can be selected from a variety of epoxy resin curing agent. 3、Foaming agent There are two types of foaming agent for epoxy resin: physical foaming agent and chemical foaming agent. Physical blowing agent is mainly low boiling point liquid, such as trichlorofluoromethane (F11), trichlorotrifluoroethane (F112), dichlorodifluoromethane (F12) and so on. The curing heat of epoxy resin is used to make the low boiling point liquid evaporate, release gas and foam, and the resulting product has low density and low thermal conductivity. However, fluorine-containing hydrocarbons have a destructive effect on the atmospheric environment and are usually used in spray foaming process. According to China Epoxy Resin Industry Association experts, toluene and other auxiliary foaming agent. In addition to foaming, it also plays the role of curing reaction heat absorber and diluent. Chemical blowing agent is mainly azo organic compounds, such as azodicarbonamide (ADCA or AC), 2,2'-azobisisobutyronitrile (AIBN) diazo-amino benzene (DAB) and so on. This foaming agent is cheap and the decomposition products are non-toxic, odorless and colorless. In addition, there are sulfonyl hydrazides, such as 4,4'-oxo-bis-benzenesulfonyl hydrazide (OBSH) and so on. When selecting, attention should be paid to the decomposition temperature. The properties of commonly used chemical blowing agents are as follows: Azodicarbonamide (AC, ADCA). Orange crystalline powder, decompose above 120℃ to produce a large amount of gas (N2, CO and a small amount of CO2), the standard state of the amount of gas 200-300mL/g, as a high-efficiency foamer. 2,2'-Azobisisobutyronitrile (AIBN, AZDN, ABN), white crystalline powder, decomposition at 98-110 ° C to release N2, the amount of gas (standard state) 130-150mL/g. Slow decomposition at room temperature, should be stored at 10 ° C or less. 4,4'-Oxybisbenzenesulfonyl hydrazide (OBSH). White or light yellow crystalline powder. Decomposes in resin at 120-140C to release N2 and water vapor. The amount of gas emission is about 120 mL/g. It does not decompose below 100℃ and has good processing safety. Sodium bicarbonate can activate it and reduce the decomposition temperature. Bubble structure is fine and uniform. 4、Surfactant(foam stabilizer) can reduce the surface tension of the liquid, which is conducive to the stabilization of the foam bubble holes uniform. Epoxy resin foam with surfactants are: polyoxyethylene sorbitan anhydride laurate (Tween 20), polydimethylsiloxane - polyolefin oxide **** polymer, ethylene oxide - propylene oxide block **** polymer (L-64). 5, filler Add filler can reduce costs, reduce the curing exothermic peak strength and shrinkage, improve the apparent quality, improve chemical resistance. Commonly used talc, quartz powder, hollow microspheres and so on. However, talc and quartz powder will make the density of the foam increase, and the mechanical properties are reduced. Hollow microspheres with very small loose density are an ideal filler. Divided into two categories of organic materials and inorganic materials. Inorganic microspheres such as glass hollow microspheres, ceramic hollow microspheres; organic microspheres such as phenolic hollow microspheres, urea-formaldehyde solid microspheres, and disposable polystyrene particles. Generally speaking, inorganic microspheres are more effective as fillers for epoxy foam. It can improve the strength, heat resistance, dimensional stability and surface smoothness of the foam. In the foam curing process will occur in the microsphere floating phenomenon, so need to add the appropriate amount of thixotropic agent. 6, thixotropic agents commonly used thixotropic agents are bentonite, diatomaceous earth, asbestos, mica, organic complexes, metal soap powder and solid vegetable oils, etc., which can stabilize the foam and microsphere position to prevent floating, delamination.