Suzhou Oushida Hot Melt Machinery Equipment Co., Ltd.

What is the reason that affects the gluing effect of PUR hot melt adhesive machine?

Company Profile

Suzhou Oushida Hot Melt Adhesive Machinery Equipment Co., Ltd. is a high-tech enterprise specializing in the research and development, production, sales and technical consulting of hot melt adhesive intelligent spraying equipment.

PUR hot melt adhesive (Polyurethane Reactive) is a new type of one-component, solvent-free hot melt structural adhesive. It cures through moisture in the air and has excellent bonding strength and impact resistance after complete curing. It also has excellent bonding strength, temperature resistance, chemical corrosion resistance and aging resistance. In recent years, it has become the best adhesive for bonding in the mobile phone and other electronic industries.

Factors and solutions that affect the process during the gluing process:

1. Influence of chemical composition of PUR hot melt adhesive

The amount of certain chemical components of PUR hot melt adhesive directly affects the viscosity of PUR. We should choose a suitable adhesive from the perspective of product performance.

2. Influence of different bonding materials

PUR hot melt adhesive has good bonding ability to different substrates, such as rubber, plastic, glass, metal, leather, wood, fabric, etc. For different bonding materials, choose the appropriate glue model.

3. The amount of glue applied

The amount of glue applied to the PUR adhesive layer will affect the curing time. If the adhesive layer is thin, the curing time will be short. In cases where the amount of glue applied is large, the amount of water in the curing adhesive will be relatively insufficient, the curing time will be longer, and it will eventually affect the bonding strength of the structural parts.

4. Glue application opening time

The specific time that the PUR hot melt adhesive applied to the sample is exposed to the air should be based on the parameters of the adhesive. Generally, the composite bonding effect is best within one minute or less. Complete the bonding within the effective opening time to avoid the phenomenon of surface drying of the glue line due to too long an opening time, resulting in poor wetting of the glue line, thereby affecting the bonding strength.

5. Pressing

After the PUR hot melt adhesive is assembled, the structural parts must be pressed together for no less than 15 seconds and the pressure should be no less than 3 kg. The purpose is to make the adhesive form a good adhesive thickness and adhesive wetting effect between the two bonding surfaces.

6. Ambient temperature and humidity

PUR hot melt adhesive is cured by moisture in the air. The higher the ambient humidity, the shorter the curing time. On the contrary, the longer the time and the higher the ambient temperature, the more moisture will participate in the reaction, and the curing time will be shortened accordingly.

7. Surface treatment of adhesive

Removing oil, dust, paint, release agent, oxide layer and other substances that affect bonding on the surface of the bonded parts is conducive to enhancing the bonding effect of PUR hot melt adhesive.

Overview of Oushida hot melt adhesive intelligent spraying equipment: