Foaming process of polyurethane rigid foam

 As the main auxiliary agent for polyurethane foaming, color paste is widely used in various polyurethane materials. As a professional polyurethane color paste manufacturer in East China, the color paste produced by our factory has the characteristics of high color concentration, good fluidity, bright color and strong weather resistance without affecting foaming when added in large quantities. ......

Polyurethane rigid foam is generally foamed at room temperature, and the molding process is relatively simple. According to the degree of construction mechanization, it can be divided into manual foaming and mechanical foaming; According to the pressure during foaming, it can be divided into high-pressure foaming and low-pressure foaming; According to the molding method, it can be divided into casting foaming and spraying foaming.

First, the advantages of foamed polyurethane

Foamed polyurethane is composed of two components, the first component is polyol, and the second component is isocyanate. During construction, the two components enter the spraying machine to mix and spray, which is foggy and foamed and solidified in one minute. This kind of material was only introduced in recent years, and it is used for building insulation and waterproofing. After two or three years of use, it has more understanding, many advantages and a wide range of applications.

1. Good thermal insulation performance. The thermal conductivity is about 0. 025, which is better than polystyrene board, and it is a good material for building thermal insulation at present.

2. Good waterproof performance. The foam holes are closed, with a sealing rate of 95%, and rainwater will not seep through the holes.

3. Because of on-site spraying, an integral waterproof layer is formed, and there is no seam, which is beyond the reach of any polymer coil, thus reducing the maintenance workload.

4. Good adhesion. Can bond with wood, metal, masonry, glass and other materials very firmly, and is not afraid of being exposed by strong winds.

5. It is very suitable for the maintenance of new roofs or old roofs, especially for the repair of old roofs. It is not necessary to remove the original waterproof layer and thermal insulation layer, just remove the dust and sand impurities on the surface and spray.

6. The construction is simple and fast. Each worker can spray more than 200 square meters every day, which is beneficial to grab the progress.

7. The closing head is simple in structure. Spray foamed polyurethane to close the head without special treatment, which is greatly simplified. If coiled material is used, a groove should be left at the parapet, and the end should be in the groove; If you can't leave a groove, you need to seal the head with a flat iron and apply caulking paste.

8. Good economic benefits. If the insulation layer and waterproof layer are separated, not only the cost is high, but also the construction period is long, and the foamed polyurethane can survive once.

9. Good aging resistance. According to the engineering summary and research test abroad, the aging resistance can reach 30 years.

Second, the application of foamed polyurethane

1. If the flat roof is not waterproof and heat-insulated, spray a color coating on the roof as a protective layer; On the roof of the master, sit on the floor with mortar paving bricks.

2. The roof with tile roof slope will spray foamed polyurethane on the lower edge of the watchboard, and the tile seat slurry will not slide on the watchboard.

3. The foamed polyurethane used for wall insulation has more advantages. Matching large wallboard, sprayed between the ribs, well bonded and tight. If hollow blocks are used, foamed polyurethane can be sprayed in the holes to fill the walls of the full freezer, especially spraying. At present, insulation technology is the key to wall reform, and foamed polyurethane can make great achievements.

4. The basement exterior wall is insulated and waterproof, which is the part where foamed polyurethane can show its talents. It can not only insulate and waterproof, but also save other protective layers, killing two birds with one stone.

Third, the shortcomings of foamed polyurethane

Although foamed polyurethane has so many advantages, it is not omnipotent, and there are shortcomings and inappropriateness.

1. At the temperature of 10℃, the foaming rate decreases. Therefore, the use is obviously restricted by the season.

2. Toilets and bathrooms only need to be waterproof instead of thermal insulation, and foamed polyurethane should not be used.

3. Foamed polyurethane spray molding speed is fast, not easy to spray very flat, uneven is normal. When used for roof waterproof and thermal insulation, the flatness can be relaxed, but the flatness of eaves gutter and gutter is not good, which will affect the drainage velocity. Therefore, it needs to be used together with other waterproof materials, and its dosage in polyurethane products is second only to polyurethane soft foam.

Polyurethane rigid foam is mostly closed-cell structure, which has excellent characteristics such as good thermal insulation effect, light weight, high specific strength and convenient construction. At the same time, it also has the characteristics of sound insulation, shock resistance, electrical insulation, heat resistance, cold resistance and solvent resistance. It is widely used as thermal insulation materials for refrigerators, freezers, refrigerated trucks, buildings, storage tanks and pipelines, and a small amount is used in non-thermal insulation occasions, such as imitation wood and packaging materials. Generally speaking, low-density rigid polyurethane foam is mainly used as thermal insulation material, while high-density rigid polyurethane foam can be used as structural material (imitation wood).

Polyurethane rigid foam is generally foamed at room temperature, and the molding process is relatively simple. According to the degree of construction mechanization, it can be divided into manual foaming and mechanical foaming; According to the pressure during foaming, it can be divided into high-pressure foaming and low-pressure foaming; According to the molding method, it can be divided into casting foaming and spraying foaming.

We respect originality. Textual beauty material, copyright belongs to the original author. Some articles cannot be contacted with the original author for various reasons. If copyright issues are involved, please contact us and deal with them immediately.

Factory Address: Longzhen Avenue, Longshan Industrial Zone, Cixi, Ningbo

Marketing Center: 1308 Yaojiang Xindu, Hongtang Street, Jiangbei, Ningbo

Telephone: +860574-86501282-0

83096225 83096226

Fax: +860574-86501283