Application and Development Trend of Automotive Adhesives/Sealants

Author: China Association of Automobile Manufacturers automobile-related industries Branch

Adhesive/sealant is one of the important process materials in automobile production. Its function penetrates into every link of the automobile manufacturing process. The structure of the car is enhanced, sealed and rust-proof, vibration reduction and noise reduction, thermal insulation, sound insulation, and internal and external protection. Decoration plays a special role in simplifying the manufacturing process, reducing the weight of the car body, and promoting the application of new structural materials in automobiles.

With the development of automotive products in environmental protection, energy conservation, safety and comfort, lightweight, low cost, long life, and pollution-free development, the development and application of new high-quality automotive adhesives/sealants has become an innovative issue that needs urgent attention in the automotive industry.

Automotive Adhesives/Sealants

From the table you can learn about the classification of automotive adhesives/sealants as well as the locations where they are used in vehicle manufacturing.

Glue for welding process—The glue for welding process includes five kinds: spot welding glue, hemming glue, reinforced shockproof glue, structural reinforcing film and high expansion damping filling glue. The adhesive/sealant used is mostly structured, The semi-structured glue plays a role in reducing solder joints, replacing welding, enhancing structure, sealing rust, and reducing vibration and noise.

This type of adhesive/sealant has excellent adhesion to oil-faced steel plates. Usually, no special heat-curing equipment is required (heat-cured in electrophoresis and other paint drying ovens), and there are no painting, cleaning, phosphating, electrophoretic, etc. painting processes. Bad effects.

Coating process adhesives—Coating process adhesives include weld seam sealant, anti-stone sealant, thermal insulation damper, and finger sealant. Although there are few types of glue, the amount of glue used is currently the largest. In the process, the average amount of bicycles is about 10 kg. At present, most of the products used are plastisol products, which have good thixotropy, can be squeezed and can be sprayed, and will not produce discoloration after the middle and topcoats are applied.

The weld sealant can prevent air, rain, dust from entering the car, and plays an important role in sealing, rust prevention, and leak prevention. The anti-stone impact paint on the vehicle floor can resist the impact of sandstone on the bottom of the vehicle, improve the anti-corrosion capability, prolong the life of the vehicle body, and reduce the noise inside the vehicle.

Assembly process and interior adhesives - Polyurethane glass adhesives are the most important type of assembly process, used for direct adhesive sealing of windshields, side window glass, etc., to replace the traditional assembly process and improve the safety factor of the entire vehicle .

There are many types of interior plastics, such as commonly used neoprene adhesives, acrylic pressure sensitive adhesives, polyurethane adhesives, butyl sealants, and adhesive tapes. Mainly used for ceiling interior materials, door waterproof membranes, door panel trim materials, etc.

Rubber for Engine and Chassis Assembly -Adhesives/Sealants for Automotive Engines, Transmissions, and Chassis Assemblies are mainly used for the sealing of various planes, hole covers, pipe joints, and bolts and shafts to prevent oil and gas. , water leaks and loose bolts.

The main varieties are anaerobic adhesives and silicone sealants and other liquid sealants. The anaerobic adhesive has good technics, fast curing speed and high strength, and can also be made into microcapsules for precoating; and the silicone rubber has good elasticity, oil resistance and aging resistance.

Adhesives for automotive parts - Adhesives/sealants are also used extensively in the production of automotive parts, such as shoe rubber for brake shoes and friction plates, adhesives for vacuum adhesives, and filter elements. Agents, osmotic sealing adhesives, adhesives for automotive lighting, interior materials, and adhesives for sound and heat insulation materials.

Development Trend of Automotive Adhesives/Sealants

According to relevant research, and the continuous application and development of new materials and processes in the automotive industry in the world, automotive adhesives/sealants have several major development directions in the future:

- Lightweight adhesives/sealants, such as low-density PVC weld sealants, low-density PVC anti-knock paints, etc.

The density of the ordinary PVC sealing material is 1.40 g/cm3, while the density of the low density PVC sealing material can reach 0.9-1.0 g/cm3. The quality can be reduced by 30% to 35 when using the same thickness (volume) sealing material. %.

- Green type adhesive/sealant.

At present, water-based materials have begun to appear and replace oil-based bonding and sealing products. The use of water-based paints can replace the widely used PVC plastisols instead of asphalt-based damping plates used in cars. As the water-based material can be air-drying or drying, the damping coefficient is higher than that of PVC and asphalt materials, and the environmental pollution is small, and the application prospect is very good.

In addition, green PVC sealant and anti-stone impact paint are also applied in the automobile manufacturing process.

- wet touch wet PVC sealing material.

At present, the paint shop of the new automobile factory no longer has a PVC pre-drying oven to increase production efficiency and save energy. This process requires that PVC sealing materials (sealant, anti-knock paint, and antiskid protection coating for skirts) have a good match for intermediate paints. The so-called wet-on-wet process means that the PVC sealing material does not undergo a pre-curing (pre-gel) process and is applied directly to the surface of the wet PVC material, and the PVC material is to be applied to the intermediate coating in the intermediate coating drying oven. The layers are dried together. This requires that the PVC material has good adaptability to the middle paint, and there is no phenomenon such as hair growth, sagging, shrinkage, and pinhole.

Application area Application process, type of adhesive/sealant
Automotive Body Welding and Assembly Lines Spot Welding, Folding Rubber, Reinforced Anti-Vibration, Reinforced Film, High Expansion Damping Filler
Coating line weld sealant, anti-stone anti-rust coating, finger pressure sealant, thermal insulation damper
Windshield Body Windshield and Side Window Glass Adhesives/Sealants
Adhesives for auto glass windows, adhesives for door seals, adhesives for floor/sealant, adhesive sealants for door and window seals, adhesives for composite structures, trademarks and adhesive tapes for interior and exterior trim, roofs, side panels, Interior parts such as doors and trunk panels Adhesives, plastic decorative parts Adhesives
Automotive Assembly Various types of liquid anti-leak sealant for engine and chassis assembly, thread lock adhesive sealant, etc.
Parts Brake Shoe Adhesive, Rubber Sealing Strip Sealant, Filter and Filter Adhesive Sealant, Car Lamp Adhesive Sealant, Horn Adhesive, Seat Adhesive, Adhesive for Rubber Metal Composite Parts, Fuel Tank , water tank sealant, anti-seepage agent and anti-corrosion coating
Mould material Automobile master model, inspection tool with processing plastics and supporting glue, casting mandrel, sand rubber
Manufacturing Process Process Protection Tapes and Assembly Fixing Tapes, Strippable Protective Coatings, Tool Adhesives, Various Repair Adhesive Sealants, Other Process Adhesives