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

Factors and solutions that affect the production process during the gluing process of the product:

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. From the perspective of product performance, we must choose a suitable glue.

2. The influence of different bonding materials

PUR hot melt adhesive has good bonding ability to different base materials, 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 PUR adhesive layer applied will affect the curing time. If the adhesive layer is thin, the curing time will be short. When the amount of glue applied is large, the moisture content of the cured glue will be relatively insufficient, and the curing time will be longer, which will ultimately affect the bonding strength of the structural parts.

4. Dispensing opening time

The specific time for the PUR hot melt adhesive applied on the sample to be exposed to the air should be based on the parameters of the adhesive. Generally, within one minute or less, the composite bonding effect is optimal. Complete the bonding within the effective opening time to prevent the glue line from drying out due to too long opening time, resulting in poor wetting effect of the glue line and thus affecting the strength of the bond.

5. Pressing

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

6. Ambient temperature and humidity

PUR hot melt adhesive is cured by moisture in the air. If the ambient humidity is high, the curing time will be short. On the contrary, if the time is long and the ambient temperature is high, it is conducive to the participation of moisture in the reaction, and the curing time will be shortened accordingly.

7. Adhesive surface treatment

Removing oil, dust, paint, release agents, oxide layers and other substances that affect bonding on the surface of the bonded parts will help enhance the bonding effect of PUR hot melt adhesive.

Our hot melt glue machine is equipped with a temperature standby setting function, which can set the insulation temperature according to actual production requirements to prevent glue carbonization, reduce power consumption, shorten the heating time due to shift changes or lunch breaks, and prevent the glue from being overheated during breaks. affecting its performance, thereby causing inconvenience. At the same time, the hot melt glue machine also has a temperature over-temperature alarm and power-off protection function. When the actual temperature exceeds the set value, the main power supply automatically shuts down to avoid production accidents.

When operating a hot melt adhesive machine, you need to pay attention to the following points:

1. The temperature should be moderate (150-180°C), and cannot be heated above 200°C for a long time. This will cause damage to the glue, promote premature aging of the hot melt adhesive, and affect the bonding effect. Heating for 40 minutes to 60 minutes before construction , wait until the hot melt adhesive melts into a liquid state before applying.

2. After feeding the hot melt glue tank, close the lid of the glue tank immediately to avoid contamination by foreign impurities; if the temperature is appropriately lowered to 120°C during a break, just keep the temperature in the heat preservation state.

3. When you get off work every day, in addition to turning off the power of the machine, put two pieces of cold glue into the glue tank to promote cooling and speed up heat dissipation.

4. If the machine is used for a period of time (such as 6 months), the nozzle, hose, and melt tank should be cleaned regularly with special cleaning agents to avoid impurities or carbon deposits from affecting the construction of the machine. Please refer to the product's operating guide before use.