1、 The important role of adhesives and bonding technology

With the development of economy and science, industry, agriculture, transportation, medical treatment, national defense and people's daily life are inseparable from adhesives. Almost everyone and everything involves adhesives. Adhesives in China started in the 1950s. After entering the 1990s, the adhesive industry has developed by leaps and bounds, and adhesives have become an important class of fine chemical products. It can be said that where there are human beings, there is no shortage of adhesive products and bonding technology. It provides new and practical processes for Industry and creates a colorful life for human beings.

Adhesives and bonding technology play an increasingly important role in structural connection, assembly reinforcement, shock absorption and seismic resistance, weight reduction and growth rate, decoration, waterproof and anti-corrosion, emergency repair, etc., especially in energy conservation, environmental protection, safety, and the development of new technologies, new processes and new products, which have become important engineering materials and process methods.

Bonding technology is a special process unparalleled in other connection methods, which plays an important role in modern economy, modern national defense and modern science and technology. There are many bonding parts and large bonding areas on various aircraft in modern aerospace and aviation, such as the fuselage, wing, operating surface, fairing, integral fuel tank and other parts of the B-1 aircraft, whose bonding area is as high as 80% of the total surface area; The bonding area of Boeing 747 aircraft is about 3000 square meters. The aircraft adopts adhesive connection, the structural mass is reduced by 15%, and the total cost is saved by 25~30%. A heavy bomber used bonding instead of riveting, resulting in a 34% reduction in structural quality. A large radar adopts adhesive structure, and its mass is reduced by 20%. The weight of car body can be reduced by about 10% by using bonding instead of spot welding. The ship's hull is made of adhesive honeycomb sandwich panels, which can reduce the mass by 40% and improve the running speed and safety.

With the lightweight, high-speed and comfort of the automobile, it is inevitable to use a large number of thin-walled structures and plastic parts, and bonding is a better connection method. Modern buildings are required to be beautiful and novel, indoor facilities are exquisite, comfortable and luxurious, and decorative materials are diverse. Adhesives play a special role in buildings, such as light weight, energy saving, sealing, leak proof, heat preservation, antifouling, durability and so on. The application of adhesive in medical treatment is rising and popularizing. It is used for repairing viscera, bone grafting and skin grafting, suturing and hemostasis, repairing tympanic membrane, etc.

Adhesive and bonding have many functions, such as connection, sealing, insulation, shock absorption, heat insulation, silencing, damping, noise reduction, moisture-proof, adhesion, conductivity, magnetic conductivity, wear reduction, oil resistance and so on.

The amount of adhesive is small and the effect is not small; The cost is not much, and the effect is great. For example, the well-known 502 instant dry glue dosage is measured in drops, the curing is measured in seconds, and the strength is measured in tons. The bonding efficiency is very high. In the past 20 years, the development rate of bonding and sealing technology is 2.5 times faster than the traditional riveting connection. It is believed that adhesives and bonding technology will play a more important role in the production and life of modern society.

2、 Characteristics of adhesives and bonding technology

Novel and unique adhesive and bonding technology, with extraordinary multi-function, can achieve multiple purposes, and has many characteristics compared with riveting, welding, bolting, bonding, tenon and so on. For the same or different materials with the same or different material, shape, thickness, size, modulus, etc., it can be effectively bonded, especially suitable for the bonding and connection of deformed, heterogeneous, thin-walled, complex, tiny, hard brittle or heat sensitive parts.

The stress distribution is uniform, the structure is not weakened, and fatigue cracking caused by stress concentration around rivet holes, screw holes and spot welding is avoided, thus prolonging the service life.

No deformation, warpage, hardness reduction, coating damage, residual stress or thermal shock caused by welding. Bonding different metals, there is no danger of electrochemical corrosion, and it has anti-corrosion effect. The strength is higher. The shear strength of the joint with the same area is 40% - 100% higher than that of welding and riveting, and the fatigue strength is 5-6 times higher. Smooth surface can improve aerodynamic characteristics. It can save the number of parts and valuable materials, reduce the structural quality and realize lightweight.

It has many functions, such as connection, insulation, sealing, corrosion prevention, moisture-proof, shock absorption, weight reduction, heat insulation, noise elimination, conductivity, magnetic conductivity and so on. It can simplify the process, does not require high machining accuracy, and does not need post-processing such as correction and finishing. There is no need for huge equipment, no special conditions, and the operation is simple and easy. It can be connected under special conditions, such as underwater bonding, field operation, plugging of chemical equipment under high temperature and high pressure without stopping, bonding of oil pipelines under pressure, repair of tanks or devices containing flammable media, as well as medical organ repair, hemostasis suture, etc.

Fast bonding, solve urgent problems, shorten the construction period, save resources, reduce costs, reduce costs, and improve efficiency and economic benefits.

However, bonding cannot completely replace the traditional connection methods. If it can be used together with welding, riveting, bolting, caulking, etc., it can give play to their respective advantages and receive better results.

3、 Development direction and Prospect of adhesives

In recent years, with the vigorous development of automobile, household appliances, building materials, aerospace industry, decoration engineering, water conservancy and transportation, information industry, electronic instruments and electronic appliances, the demand for adhesives in various industries and the demand for adhesive varieties under different conditions are also increasing. At the same time, higher and higher requirements are put forward for the adhesive, the efficiency of the bonding process and environmental pollution. In general, the development direction of adhesives in the future is as follows:

First, with the increasing voice of environmental protection and the improvement of environmental protection laws and regulations, environment-friendly adhesives have gradually become the mainstream of development.

Second, in recent years, high-quality, high-performance and high value-added adhesives have sprung up, becoming a new profit growth point and a new research hotspot in the adhesive market.

Third, the rubber with complex synthesis process and strict equipment requirements is not easy to be popularized and applied, while the high-performance "green" environmental friendly adhesive with wide raw material sources, easy preparation and convenient use will become the "Darling" of the market.

After clarifying the development direction of adhesives, we need to strive to improve the technical content of adhesive products, which can be considered from the following aspects:

1. New formulas are designed with new peculiar properties to adapt to more severe working environment conditions. Such as aerospace adhesive, American ast Me595 standard stipulates that aerospace adhesives and sealing materials in high vacuum 710-3pa, temperature 125ci=, 24-hour material mass loss ≯ 1%, condensable volatile ≯ 0.1%, water recovery {2.5ci=} ≯ 0.1%. In the past, only a few Aerospace countries such as the United States and Russia were able to produce this material. In recent years, China has successfully developed adhesives and potting materials for aerospace micro and special motors and components that meet the requirements of astme595.

2. The introduction of new technologies to improve the performance of adhesives, the application of nanotechnology is no longer a fantasy, and practical progress has been made in the development of many materials. The Institute of solid state physics of the Chinese Academy of Sciences, the Institute of physics, Shanghai University, Qingdao University of chemical technology, East China University of science and technology, and others have made new achievements. Functional high-strength carbon tubes and PP plastics have made practical progress. This confirms that nanoparticles can improve the cohesive strength of polymer materials and crystalline materials, and can play a reinforcing role in adhesives. The introduction of nanoparticles has made tough ceramics, and there is a new idea for the toughening of inorganic adhesives. The latex paint reflecting ultraviolet ray has been put into production, and has weather resistance, foreign matter absorption resistance, antibacterial, algae resistance, weathering resistance, artificial aging test life of more than 10 years, and brushing resistance of more than 6oo0 times.

3. Research and development of automatic production equipment in the past, the feeding and temperature control of reaction kettle were mostly manual or semi-automatic control, and computer control will be gradually promoted in the future.

4. Develop convenient, fast and accurate construction equipment, with automatic cleaning structure after use.

5. Strengthen standardized management, manufacture testing equipment and instruments, and strengthen the quality monitoring of adhesive raw materials, processes and finished products.