Pmi core foam chemistry
The core foam chemistry principles can be divided into two categories.
A chemical blowing agent that releases gas upon heating is used. Common chemical foaming agents such as azodicarbonamide, azobisisobutyronitrile, N,N'-dinitrosopentamethylenetetramine, sodium hydrogencarbonate. Many thermoplastics can be made into foam in this way. For example, PVC foam shoes are made from resins, plasticizers, foaming agents and other additives for use in injection molding machines. The blowing agent ruptures in the barrel and the material foams in the mold. . The foamed artificial leather is mixed with a foaming agent to prepare a polyvinyl chloride paste. Scratching or calendering on the fabric, continuously passing through the tunnel furnace, the material is plasticized and melted, the blowing agent is decomposed and foamed, cooled and the surface finish is made from foamed artificial leather. Forming rigid PVC low foam sheets, tubes or profiles by extrusion. The blowing agent decomposes in the barrel. When the material leaves the handpiece, the pressure drops to atmospheric pressure and the dissolved gas expands and foams. The foaming process is well suited for cooling and curing processes to obtain structural foam products.
A typical example is a by-product gas of the polymerization process, which is a polyurethane foam. When the isocyanate undergoes a polycondensation reaction with a polyester or a polyether, a portion of the isocyanate reacts with water, a hydroxyl group or a carboxyl group to form carbon dioxide. As long as the gas generation rate and the polycondensation reaction rate are appropriately adjusted, a highly foamed product having very uniform bubbles can be produced. There are two types of polyurethane foam: soft open sponge, widely used as seat cushion, sofa cushion, sound absorbing material, filter material, etc. The hard closed bore type is ideal for insulation, insulation, shock absorption and floating materials.
A chemical blowing agent that releases gas upon heating is used. Common chemical foaming agents such as azodicarbonamide, azobisisobutyronitrile, N,N'-dinitrosopentamethylenetetramine, sodium hydrogencarbonate. Many thermoplastics can be made into foam in this way. For example, PVC foam shoes are made from resins, plasticizers, foaming agents and other additives for use in injection molding machines. The blowing agent ruptures in the barrel and the material foams in the mold. . The foamed artificial leather is mixed with a foaming agent to prepare a polyvinyl chloride paste. Scratching or calendering on the fabric, continuously passing through the tunnel furnace, the material is plasticized and melted, the blowing agent is decomposed and foamed, cooled and the surface finish is made from foamed artificial leather. Forming rigid PVC low foam sheets, tubes or profiles by extrusion. The blowing agent decomposes in the barrel. When the material leaves the handpiece, the pressure drops to atmospheric pressure and the dissolved gas expands and foams. The foaming process is well suited for cooling and curing processes to obtain structural foam products.
A typical example is a by-product gas of the polymerization process, which is a polyurethane foam. When the isocyanate undergoes a polycondensation reaction with a polyester or a polyether, a portion of the isocyanate reacts with water, a hydroxyl group or a carboxyl group to form carbon dioxide. As long as the gas generation rate and the polycondensation reaction rate are appropriately adjusted, a highly foamed product having very uniform bubbles can be produced. There are two types of polyurethane foam: soft open sponge, widely used as seat cushion, sofa cushion, sound absorbing material, filter material, etc. The hard closed bore type is ideal for insulation, insulation, shock absorption and floating materials.
Article Source：https://www.pmifoam.com/news/pmi-core-foam-chemistry.html
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