Circular 65 is invalid, and the spring of eps foam industry is coming.
The materials and equipment of Grade A polystyrene insulation board (PEPS) will be born soon, which is worth looking forward to.
Among the raw materials of foam, which raw materials account for a larger proportion? What are the materials with high production cost?
1, bisphenol a epoxy resin is mostly used as epoxy resin, with an epoxy value of 0.51~ 0.22 mol/100g .. and a viscosity of 20Pa·s；; At 25℃; The viscosity is 65438±0Pa·s at 65438 030℃. 2. The curing agent can be various epoxy curing agents. 3. Foaming agent There are two kinds of foaming agents for epoxy resin: physical foaming agent and chemical foaming agent. Physical foaming agents are mainly low-boiling liquids, such as trichlorofluoromethane (F 1 1), trichlorotrifluoroethane (F 1 12), dichlorodifluoromethane (F 12) and so on. Using the curing heat of epoxy resin, low boiling point liquid is evaporated and gas is released for foaming. The product has low density and low thermal conductivity. However, fluorine-containing hydrocarbons have destructive effects on the atmospheric environment and are usually used in spray foaming process. According to experts from China Epoxy Resin Industry Association, toluene can be used as an auxiliary foaming agent. In addition to foaming, it also acts as an endothermic agent and diluent for curing reaction. Chemical foaming agents are mainly azo organic compounds, such as azodicarbonamide (ADCA or AC), 2,2'-azodiisobutyronitrile (AIBN), diazoaminobenzene (DAB) and so on. The foaming agent is low in price, and the decomposition product is nontoxic, tasteless and colorless. In addition, there are sulfonylhydrazides, such as 4,4'-oxo-diphenyl sulfonyl hydrazine (OBSH). Pay attention to the decomposition temperature when choosing. The properties of common chemical foaming agents are as follows: azodicarbonamide (AC, ADCA). Orange crystalline powder. The decomposition above 120℃ produces a large number of gases (N2, CO and a small amount of CO2), and the gas emission is 200 ~ 300ml/g in the standard state, which is an efficient foaming agent. 2,2'-azodiisobutyronitrile (AIBN, AZDN, ABN), a white crystalline powder, decomposes at 98 ~ 1 10℃ to release N2, and the gas production (standard state) is130 ~150ml/g. 4,4'-oxydiphenyl sulfonyl hydrazine. White or yellow crystalline powder. In the resin, 120 ~ 140c points explain the release of N2 and water vapor. The gas production rate is about 120 mL/g 100℃, which does not decompose and has good processing safety. Sodium bicarbonate can activate it and reduce the decomposition temperature. The cell structure is fine and uniform. 4. Surfactant (foam stabilizer) can reduce the surface tension of liquid, which is beneficial to foam stability and cell uniformity. Surfactants used for foaming epoxy resin include polyoxyethylene sorbitan laurate (Tween 20), polydimethylsiloxane-polyoxyalkylene copolymer and ethylene oxide-propylene oxide block copolymer (L-64). 5. Adding filler can reduce the cost, reduce the curing exothermic peak strength and shrinkage, improve the apparent quality and improve the chemical resistance. Commonly used are talcum powder, quartz powder and hollow microspheres. However, talcum powder and quartz powder will increase the density of foamed plastics and reduce their mechanical properties. Hollow microspheres with low bulk density are an ideal filler. It can be divided into organic materials and inorganic materials. Inorganic microspheres, such as glass hollow microspheres and ceramic hollow microspheres; Organic microspheres, such as phenolic hollow microspheres, urea-formaldehyde solid microspheres, expandable polystyrene particles. Generally speaking, inorganic microspheres are more effective as fillers of epoxy foam. It can improve the strength, heat resistance, dimensional stability and surface smoothness of foamed plastics. In the process of foaming and curing, microspheres will float, so it is necessary to add a proper amount of thixotropic agent. 6. Thixotropic agents commonly used are bentonite, diatomite, asbestos, mica, organic complex, metal powder, solid vegetable oil, etc., which can stabilize the position of foam and microspheres and prevent them from floating and delamination.
What material is foam packaging?
There are many kinds of foam packaging, such as cheap EPS foam, recyclable EPP, EPO and so on. EPP single-layer and multi-layer foaming are also commonly used;
What material are foam particles made of?
polystyrene
What material is the foam box made of?
Polyurethane foam, code: r141b.
What are the raw materials of foamed plastics and how are they made?
1, epoxy resin
Bisphenol a epoxy resin with epoxy value of 0.51~ 0.22 mol/100 g is often used. The viscosity is 20Pa·s；; At 25℃; The viscosity is 65438±0Pa·s at 65438 030℃.
2. Curing agent
Various epoxy curing agents can be selected.
3. Foaming agent
There are two kinds of foaming agents for epoxy resin: physical foaming agents and chemical foaming agents. Physical foaming agents are mainly low-boiling liquids, such as trichlorofluoromethane (F 1 1), trichlorotrifluoroethane (F 1 12), dichlorodifluoromethane (F 12) and so on. Using the curing heat of epoxy resin, low boiling point liquid is evaporated and gas is released for foaming. The product has low density and low thermal conductivity. However, fluorine-containing hydrocarbons have destructive effects on the atmospheric environment and are usually used in spray foaming process. According to experts from China Epoxy Resin Industry Association, toluene can be used as an auxiliary foaming agent. In addition to foaming, it also acts as an endothermic agent and diluent for curing reaction.
Chemical foaming agents are mainly azo organic compounds, such as azodicarbonamide (ADCA or AC), 2,2'-azodiisobutyronitrile (AIBN), diazoaminobenzene (DAB) and so on. The foaming agent is low in price, and the decomposition product is nontoxic, tasteless and colorless. In addition, there are sulfonylhydrazides, such as 4,4'-oxo-diphenyl sulfonyl hydrazine (OBSH). Pay attention to the decomposition temperature when choosing. The properties of commonly used chemical foaming agents are briefly described as follows:
Azodiformamide (AC, ADCA). Orange crystalline powder. The decomposition above 120℃ produces a large number of gases (N2, CO and a small amount of CO2), and the gas emission is 200 ~ 300ml/g in the standard state, which is an efficient foaming agent.
2,2'-azodiisobutyronitrile (AIBN, AZDN, ABN), a white crystalline powder, decomposes at 98 ~ 1 10℃ to release N2, and the gas production (standard state) is130 ~150ml/g.
4,4'-oxydiphenyl sulfonyl hydrazine. White or yellow crystalline powder. In the resin, 120 ~ 140c points explain the release of N2 and water vapor. The gas production rate is about 120 mL/g 100℃, which does not decompose and has good processing safety. Sodium bicarbonate can activate it and reduce the decomposition temperature. The cell structure is fine and uniform.
4. Surfactant (foam stabilizer)
The surface tension of liquid can be reduced, which is beneficial to the stability and uniformity of foam cells. Surfactants used for foaming epoxy resin include polyoxyethylene sorbitan laurate (Tween 20), polydimethylsiloxane-polyoxyalkylene copolymer and ethylene oxide-propylene oxide block copolymer (L-64).
Step 5 fill in the blanks
Adding filler can reduce the cost, reduce the curing exothermic peak strength and shrinkage, improve the apparent quality and improve the chemical resistance. Commonly used are talcum powder, quartz powder and hollow microspheres. However, talcum powder and quartz powder will increase the density of foamed plastics and reduce their mechanical properties. Hollow microspheres with low bulk density are an ideal filler. It can be divided into organic materials and inorganic materials. Inorganic microspheres, such as glass hollow microspheres and ceramic hollow microspheres; Organic microspheres, such as phenolic hollow microspheres, urea-formaldehyde solid microspheres, expandable polystyrene particles. Generally speaking, inorganic microspheres are more effective as fillers of epoxy foam. It can improve the strength, heat resistance, dimensional stability and surface smoothness of foamed plastics. In the process of foaming and curing, microspheres will float, so it is necessary to add a proper amount of thixotropic agent.
6. Thixotropic agent
Commonly used thixotropic agents include bentonite, diatomite, asbestos, mica, organic complex, metal powder, solid vegetable oil, etc., which can stabilize the position of foam and microspheres and prevent them from floating and delamination.