What are the advantages and common types of PU adhesives?
In recent years, in order to meet the requirements of the lightweight development of auto parts, plastic parts are widely used in automobile manufacturing, especially high-strength FRP (glass fiber reinforced plastic) and SMC (sheet molding composites), so the advantages of PU adhesives and What are the common types?
In recent years, in order to meet the requirements of lightweight development of auto parts, plastic parts are widely used in automobile manufacturing, especially high-strength FRP (glass fiber reinforced plastic) and SMC (sheet molding composites).PU adhesiveWhat are the advantages and common types?
Modern cars need the safety of windows and windshields. The windshield adopts direct bonding technology, and a large number of one-component moisture-curing PU adhesives are used. In order to improve the environmental performance of polyurethane adhesives, waterborne polyurethane adhesives, solvent-free polyurethane structural adhesives and reactive polyurethane hot melt adhesives were developed. Anti-yellowing agents are widely used in the formulation of automotive polyurethane adhesives, which can effectively improve the weather resistance of adhesives and meet the requirements of anti-yellowing properties of adhesives.
1.PU adhesive has good bonding properties between -40~100, good toughness, excellent shock and vibration resistance, and long service life, especially at low temperatures;
2. It contains a large number of polar groups and active reactive groups, and has excellent adhesion to various substrates used in automobiles, such as glass, plastic, metal and other materials with smooth surfaces, various interior and exterior decorative materials and fabrics.
3. By adjusting the formula of PU glue, adhesives with different hardness and elongation can be made, and the adhesive layer can be adjusted from flexible to rigid to meet the bonding of different materials;
4. It can be cured by heating at room temperature, the bonding process is simple, and the operation performance is good. There is no side reaction in the curing process, and the adhesive layer is not easy to produce defects;
5.PU glue has good abrasion resistance, oil resistance, solvent resistance, chemical resistance, ozone resistance and antibacterial properties.
PU adhesive: How many kinds of adhesive are there?
1. There are many applications and developments of one-component moisture-curing polyurethane windshield glue, such as high modulus one-component polyurethane glass glue, high contact viscosity one-component polyurethane glass glue, pre-coated one-component polyurethane glue and Process, silane modified polyurethane sealant and low conductivity 2. One-component polyurethane glue is used to prevent corrosion of aluminum car body and adverse effects on antenna reception.
2. One-component moisture-curing polyurethane adhesives contain active-NCO groups and can be cured by reacting with trace moisture in the air or on the surface to be stuck. One-component moisture-curing PU windshield glass glue is required to be sensitive to moisture, fast curing speed, excellent elasticity after curing, single package, and good storage stability.
3. It is a product with high technical content in automobile adhesives, and it is also the PU glue used in automobiles in my country. One-component moisture-curing polyurethane adhesives are suitable for bonding porous surfaces. For non-porous surfaces such as glass and metal, it is usually necessary to cooperate with glass activator, glass primer and paint primer.
4. In order to ensure the reliable bonding performance between the windshield and the car body, it is necessary to coat the glass surface with a primer, which can improve the bonding strength of the PU glue on the glass layer. At present, one-component polyurethane adhesives have been localized and have been partially used in the automotive industry. However, this one-component PU glue needs to be combined with a glass activator, a paint surface and a glass primer to ensure sufficient bonding strength, and the curing speed is slow and the assembly process is complicated.
5. Therefore, there is no need to use activators, primers and instant positioning windshield adhesives. For example, when assembling the windshield, it is equipped with a heating coating device, so that the slightly heated bonding material immediately produces a higher initial bonding strength on the surface to be bonded, ensuring the positioning of the window glass, and then gradually achieving complete curing, which solves the problem The PU glue has a slow curing speed and the inconvenience of assembling fixtures. Three. Waterborne polyurethane adhesive for automotive interior parts.
6. Water-based PU glue refers to the adhesive formed by dissolving or dispersing polyurethane in water. It has the advantages of non-combustible, small odor, no pollution to the environment, energy saving, and convenient operation and processing. At first, it was used for leather finishing, fabric finishing and coating. Later, it was gradually applied to the bonding of automotive interior parts. The solid content and viscosity of the water-based PU glue can be adjusted according to user requirements. It can be cured at room temperature or thermally cured. At present, water-based PU glue has been used to bond some auto parts, such as PVC artificial leather, instrument panels, fenders, door panels, carpets, ceiling linings, PVC film composite polyurethane foam or fabric composite polyurethane foam soft tops for automobile ceilings Wait.
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