Views: 2 Author: Site Editor Publish Time: 2023-06-19 Origin: Site
Rigid polyurethane foam, referred to as polyurethane rigid foam, which is second only to polyurethane flexible foam in the amount of polyurethane products.
I. Polyurethane Rigid Foam Basic Knowledge
Polyurethane rigid foam is mostly closed-cell structure, which has excellent characteristics such as good insulation effect, light weight, high specific strength and convenient construction, and also has the characteristics of sound insulation, shockproof, electric insulation, heat resistance, cold resistance and solvent resistance, etc. It is widely used as insulation material for refrigerator and freezer's box insulation layer, cold storage and refrigerated car, building, storage tank and pipeline insulation material, and a small amount is used for non-insulation occasions, such as imitation wood and packaging material, etc. Generally speaking, the lower density polyurethane rigid foam is mainly used as heat insulation (insulation) materials, and the higher density polyurethane rigid foam can be used as structural materials (imitation wood).
Polyurethane rigid foam is generally room temperature foaming, molding process is relatively simple. According to the degree of construction mechanization can be divided into manual foaming and mechanical foaming; according to the pressure of foaming can be divided into high-pressure foaming and low-pressure foaming; according to the molding method can be divided into pouring foaming and spraying foaming.
The main uses of polyurethane rigid foam are as follows:
1. Food and other industries freezing and refrigerating equipment: such as refrigerators, freezers, cold storage, refrigerated trucks, etc. Polyurethane rigid foam is the most ideal insulation material for freezing and refrigerating equipment.
2. Industrial equipment insulation: such as storage tanks, pipelines, etc.
3. Construction materials: In developed countries in Europe and America, polyurethane rigid foam for construction accounts for about half of the total consumption of rigid foam and is more than double the amount of rigid foam used in refrigerators and freezers; in China, the application of rigid foam in the construction industry is not yet as common as in the developed countries in the West, so the potential for development is very large.
4. Transportation industry: such as car tops, interior parts, etc.
5. Wood-like material: high-density (density 300-700kg/m3) polyurethane rigid foam or glass fiber reinforced rigid foam is structural foam, also known as wood-like, with high strength, good toughness, dense and tough crust, simple molding process, high production efficiency, high strength compared to natural wood, low density compared to natural wood, can replace wood as a variety of high-grade products.
6. Potting materials, etc.
II. Polyurethane Flexible Foams Basic Knowledge
Flexible polyurethane foam, referred to as polyurethane flexible foam, is a soft polyurethane foam with a certain degree of elasticity, it is the largest amount of polyurethane products in polyurethane products a polyurethane product.
Polyurethane soft foam is mostly open pore structure, with low density, good elastic response, sound absorption, breathable, heat preservation and other properties, mainly used as furniture cushion material, mattress, transportation seat cushion and other cushion materials, industrial and civil use of soft foam as filter materials, sound insulation materials, shockproof materials, decorative materials, packaging materials and thermal insulation materials.
According to the different degrees of softness and hardness, i.e. load resistance, polyurethane soft foam can be divided into ordinary soft foam, super soft foam, high load-bearing soft foam, high resilience soft foam, etc. Among them, high resilience soft foam and high load-bearing soft foam are generally used in the manufacture of seat cushions and mattresses. According to the different production process, polyurethane soft foam can be divided into block soft foam and molded soft foam, block soft foam is produced through the continuous process to produce a large volume of foam and then cut into the required shape of foam products, molded soft foam is directly mixed with raw materials through the interstitial process and then injected into the mold foam into the required shape of foam products.
Main applications of polyurethane flexible foam
Cushion material: such as seats, sofas, mattresses, etc., polyurethane flexible foam is a very ideal cushion material, cushion material is also the largest amount of soft foam applications.
Sound-absorbing material: The open-hole polyurethane soft foam has good sound absorption and vibration elimination function, and can be used as indoor sound insulation material.
Fabric composites: toys, etc.