What is PUR hot melt adhesive?

1 concept

PUR (Polyurethane Reactive), the Chinese full name is moisture curing reactive polyurethane hot melt adhesive. The main component is isocyanate-terminated polyurethane prepolymer. The adhesion and toughness (elasticity) of PUR can be adjusted, and it has excellent bonding strength, temperature resistance, chemical corrosion resistance and aging resistance. In recent years, it has become one of the important varieties in the adhesive industry. Now it is widely used in packaging, wood processing, automobile, textile, electromechanical, aerospace and other national economic fields.

 

2 Properties of polyurethane hot melt adhesive

The reactive hot melt adhesive is heated and melted into a fluid under the condition of inhibiting the chemical reaction, so as to facilitate coating; after the two adherends are bonded and cooled, the adhesive layer condenses to play a bonding role; and then with the help of moisture in the air It reacts with the moisture attached to the surface of the adherend, extends the chain, and generates a high-molecular polymer with high cohesion, which significantly improves the adhesion, heat resistance, and low temperature resistance. Due to its extremely high reactivity, it shows excellent adhesion to various materials, and is widely used in washing machine top covers, disinfection cabinet top covers, book binding, car lights, furniture edge banding, shoemaking etc. bonding.

PUR adhesive is a polar and chemically active urethane group (-NHCOO-) or isocyanate group (-NCO) in its molecular structure, and it can be used with materials containing active hydrogen, such as porous materials such as wood, leather, fabric, paper, ceramics, etc. It has excellent adhesion to plastic, metal, glass, rubber and other smooth surface materials.

 

3 Types of Polyurethane Hot Melt Adhesives

According to chemical properties, polyurethane hot melt adhesives can be divided into two categories, one is thermoplastic polyurethane hot melt adhesives, and the other is reactive polyurethane hot melt adhesives. The former is liquefied by heating and then solidified by cooling, while the latter is liquefied by heating and then cross-linked and solidified by cooling and moisture reaction. Thermoplastic polyurethane hot melt adhesive is also called hot melt polyurethane hot melt adhesive (TPU). The reactive polyurethane hot melt adhesive (PUR) can be divided into moisture curing polyurethane hot melt adhesive and closed polyurethane hot melt adhesive.

Polyurethane hot melt adhesives also have other classification criteria, such as according to shape, can be divided into three types: film, tape and powder. After the solution volatilizes on the surface of the material to be bonded, it becomes a hot melt adhesive film. Tapes are backed with a reinforcement or carrier, while films are supported by the adhesive itself.

Dear Sir/Madam

Thank you for being able to see the end. In our Purking company, there is a laboratory specializing in customized services. You can also choose the hot melt adhesive you need above our products, and we will reply you as quickly as possible.

best regards

jerry

Manager