PUR Hot Melt Adhesive (Polyurethane Reactive) as a new type of single-component, solvent-free hot melt structural adhesive, its air by moisture curing, fully cured with excellent bonding strength and impact resistance, but also has excellent bonding strength, temperature resistance, chemical resistance and aging resistance, in recent years it has become the mobile phone and other electronics industry adhesion of the best Adhesive.

Decide to dispense the quality and efficiency of the operation into the three major points:   

1. High-performance structural adhesives: non-corrosive, high bond strength, high initial tack, fast curing speed to meet the high rhythm of production, excellent aging resistance, weathering resistance, excellent water resistance, solvent resistance, reliable adhesion;

2. Automatic dispensing equipment: computer programming, precise positioning, stroke-controlled glue line can be controlled to prevent overflow and reduce the defective rate;

3. Perfect process: mature technology, experienced personnel, effective management system, can be completed with high quality and high efficiency production.

In terms of glue. Products in the dispensing process to the process factors and solutions:

1, the chemical composition of PUR hot melt adhesive influence

PUR hot melt adhesive certain chemical composition of how much directly affects the viscosity of PUR. We are committed to improving the performance of PUR hot melt adhesive from the perspective of product performance (such as viscosity, melt temperature, melt viscosity, initial adhesion, etc.), so choosing a suitable adhesive is a good start.

2, different bonding material impact

PUR hot melt adhesive on different substrates, such as rubber, plastic, glass, metal, leather, wood, fabric, etc. have good bonding ability, for different bonding materials, choose the right type of adhesive.

3, the amount of glue

PUR adhesive layer coating amount, will affect the curing time, if the coating layer is thin, the curing time is short. The amount of glue coated more occasions, as the amount of water curing glue will appear relatively inadequate, the curing time will be longer, but also will ultimately affect the bonding strength of structural components.

4, dispensing open time

Point in the sample on the PUR hot melt adhesive in the air exposure time must be controlled within 1min (from dispensing to assembly). In the effective open time, to complete the bonding, to avoid too long open time, the glue line appears table dry phenomenon, resulting in poor wetting effect of the glue line, thus affecting the strength of the bond.

5、Pressing

PUR hot melt adhesive assembly after the structural components must be pressed together, the time should not be less than 15 seconds, the pressure should not be less than 3 kg. The purpose is to make the adhesive between the two bonding surfaces to form a good adhesive thickness and adhesive wetting effect.

6, ambient temperature and humidity 

PUR hot melt adhesive is in the air through the moisture curing, environmental humidity, curing time is short, and vice versa, long time, high ambient temperature is conducive to moisture to participate in the reaction, curing time will be shortened accordingly.

7, bonding material surface treatment

Due to the presence of oxidation layer corrosion, chromium plating layer, phosphate layer and other boundary layer of the bonded material, the surface treatment of the bonded material will affect the bonding strength. Remove the bonded part of the surface of the oil, dust, paint, release agent, oxidation layer and other substances affecting the bond, is conducive to enhancing the PUR hot melt adhesive bonding effect.