Types and applications of adhesives

Adhesives are very common in our lives and have an important impact on our lives. What kinds of adhesives are there? Let's take a look together.

Types and applications of adhesives: polyacrylic resin;

Mainly used in the production of pressure-sensitive adhesives, but also in the textile and construction fields. In recent years, domestic enterprises have introduced many production lines of pressure-sensitive adhesive products from abroad, which has promoted the development of domestic polyacrylic resin production technology.

Polyurethane adhesive:

It can bond a variety of materials, and the physical and chemical properties of the materials can still be maintained at low temperature or ultra-low temperature after bonding. Mainly used in shoemaking, packaging, automobiles, magnetic recording materials and other fields. In recent years, the annual output of polyurethane adhesives in China has increased at an average rate of 30%. At present, about 170 factories in China produce 100 kinds of such adhesives with different specifications.

Hot melt adhesive:

According to different raw materials, it can be divided into EVA hot melt adhesive, polyamide hot melt adhesive, polyester hot melt adhesive and polyolefin hot melt adhesive. At present, EVA hot melt adhesive is mainly produced and used in China. The main raw materials of polyolefin series adhesives are ethylene series, SBS and SIS*** polymers.

Epoxy resin adhesive:

It can bond metal and most nonmetallic materials, and is widely used in buildings, automobiles, electronics, electrical appliances and daily household items. There are more than 100 factories producing epoxy resin adhesives in China, which are relatively scattered, with an annual output of about 10000 tons.

Silicone adhesive:

It is a kind of sealant with the characteristics of cold resistance, heat resistance, aging resistance, water resistance, moisture resistance, high tensile fatigue strength, small permanent deformation and non-toxicity. In recent years, this kind of adhesive has developed rapidly in China, but at present, the raw materials of silicone adhesive in China are partly imported.

Synthetic adhesive:

Mainly used in wood processing, construction, decoration, automobile, shoemaking, packaging, textile, electronics, printing and binding and other fields. At present, China imports nearly 200,000 tons of synthetic adhesives every year, including hot melt adhesive, silicone sealants, polyacrylic adhesive, polyurethane adhesive and PVC plastic adhesive for automobiles. At the same time, about 20,000 tons of synthetic adhesives are exported every year, mainly polyvinyl acetate, polyvinyl formal and pressure-sensitive adhesive.

Adhesives for wood processing:

Used for medium density fiberboard, gypsum board, plywood and particleboard.

Adhesives for construction:

Mainly used for decoration, sealing or bonding between structures in building engineering. With the development of construction industry, high-rise building and interior decoration, the amount of building adhesives has increased dramatically. The consumption of building adhesives in China is about 600,000 tons. However, experts believe that the product structure of such adhesives in China needs to be adjusted. In China, building decorative adhesives such as polyvinyl acetate, polyacrylic acid and VAE emulsion can basically meet the needs, but some building sealants and structural adhesives need to be imported from abroad.

Sealant:

Mainly used in the joints of doors and windows and prefabricated buildings. In the past, tung oil mixed with lime was used as sealant, but now it is stipulated that synthetic glue must be used for buildings with more than two floors. High-grade sealants are silicone and polyurethane, while middle-grade sealants are neoprene and polyacrylic acid. In China, silicone rubber and polyurethane sealant should be the future development direction of building sealant market, accounting for about 30% of building sealant sales at present.

Adhesives for building structures:

Mainly used for the connection between structural units. Such as external repair of reinforced concrete structure, metal reinforcement and fixation, construction site, etc., epoxy resin series adhesives are generally considered.

Adhesives for automobiles:

There are four kinds of adhesives, namely, adhesives for automobile body, adhesives for interior decoration, adhesives for windshield and adhesives for automobile body chassis. At present, the annual consumption of automotive adhesives in China is about 40,000 tons, among which PVC plastic adhesives, neoprene adhesives and asphalt series adhesives are the most widely used.

Adhesive for shoemaking:

The annual consumption is about125,000 tons, including neoprene adhesive 1 1 10,000 tons and polyurethane adhesive10.5 million tons. Because neoprene adhesive needs benzene as solvent, and benzene is harmful to human body, its development should be limited. Therefore, in order to meet the development needs of footwear industry, polyurethane series adhesives will be the direction.

Adhesive for packaging:

It is mainly used for making pressure-sensitive adhesive tapes, pressure-sensitive adhesive labels, and bonding the surfaces of packaging materials such as paper, plastic and metal. The adhesive for paper packaging materials is polyvinyl acetate emulsion. Adhesives used for plastic and metal packaging materials include polyacrylic emulsion, VAE emulsion, polyurethane adhesive and cyanoacrylate adhesive.

Adhesives for electronic equipment:

Low consumption, currently less than 10000 tons per year, most of which are used for integrated circuits and electronic products. At present, epoxy resin, unsaturated polyester resin and silicone adhesive are mainly used. We can supply the sealant for electronic components with a thickness of 5 microns, but the sealant for electronic components with a thickness of 3 microns needs to be imported from abroad.