What Is Rigid Foam Insulation?

Rigid foam refers to foam that is non-flexible, has a high compression hardness, and can deform when the stress reaches a certain value, and cannot be restored to its original state after the stress is released. ISO also stipulates that foam that is compressed to 50% and then reduced in pressure by more than 10% after being relieved of pressure is rigid foam. It often uses its thermal insulation and mechanical properties for related aspects. Typical products are polystyrene foam, rigid polyurethane foam, phenolic, amino, epoxy, thermosetting acrylic resin and other foams, and rigid polyvinyl chloride foam. Can be used as thermal insulation materials, sandwich materials, packaging materials, sound insulation and shockproof materials, construction materials, etc.

Rigid foam

Rigid foams are those that have no flexibility, high compressive hardness, and can deform when the stress reaches a certain value, and cannot be restored after the stress is released.

Rigid foam is a type of foam that refers to foam with an elastic modulus greater than 700 MPa

(1) The bulk density is very low, which can reduce the weight of packaging and reduce transportation costs;

(2) It has excellent absorption of shock and vibration energy, which can greatly reduce the damage of the product when used for shock-proof packaging;

(3) Strong adaptability to changes in temperature and humidity, which can meet the requirements of general packaging conditions;

(4) Low water absorption, low hygroscopicity, good chemical stability, it will not cause corrosion on the contents, and has strong resistance to chemicals such as acids and alkalis;

(5) Low thermal conductivity, which can be used for thermal insulation packaging, such as ice cream cups, fast food containers and fish tanks;

(6) The molding process is convenient, and various foam pads, foam blocks, sheets, etc. can be made by molding methods such as compression, extrusion, and injection. It is easy to perform secondary molding processing, such as foam board can be made into various fast food containers by thermoforming. In addition, foam plastic blocks can also be self-adhesive with other adhesives or with other materials to make various cushion pads.

Can be divided into two categories: using chemical foaming agents, they release gas when heated. Commonly used chemical foaming agents, such as azobisformamide, azobisisobutyronitrile, dinitrosopentamethylenetetramine, sodium bicarbonate, etc. Many thermoplastics can be made into foam by this method. For example, PVC foam shoes are made of resin, plasticizer, foaming agent, and other additives in an injection molding machine. The foaming agent is decomposed in the barrel and the material is foamed in the mold. . Foam artificial leather is mixed with a foaming agent in a polyvinyl chloride paste, scraped or calendered on the fabric, and continuously passed through a tunnel heating furnace. The material is plasticized and melted, the foaming agent is decomposed and foamed, cooled and surface finished. Get foam artificial leather. The rigid polyvinyl chloride low foaming sheet, pipe or profile is formed by extrusion method. The foaming agent is decomposed in the barrel. When the material leaves the head, the pressure drops to normal pressure, and the gas expands when dissolved in the gas. When the foaming process and the cooling setting process are properly matched, a structural foam product can be obtained. Using the by-product gas in the polymerization process, a typical example is polyurethane foam. When isocyanate and polyester or polyether undergo polycondensation reaction, part of the isocyanate will react with water, hydroxyl or carboxyl group to generate carbon dioxide. As long as the gas evolution rate and the polycondensation reaction rate are properly adjusted, a highly foamed product with very uniform cells can be produced. There are two types of polyurethane foam. The soft open-cell shape is like a sponge, which is widely used as a seat cushion, sofa cushion, sound-absorbing and filtering material. The rigid closed-cell type is ideal for heat insulation, insulation, and shock absorption. And floating materials.

There are many classification methods for foam plastics, and there are three common ones.