How to better use PUR hot melt adhesive
PUR hot melt adhesive(Polyurethane Reactive) is a new one-component, solvent-free hot-melt structural adhesive. It is moisture-cured in the air and has excellent bond strength and impact resistance when fully cured. Excellent bonding strength, temperature resistance, chemical resistance and aging resistance have become the best bonding adhesives in the electronics industry such as mobile phones in recent years.
How to improve the quality and efficiency of dispensing work more effectively has become the focus of everyone's attention. Generally speaking, we think it is decided by the following three points:
Non-corrosive, high bond strength
High initial adhesion, fast curing speed, high-ratio production
Excellent aging resistance, weather resistance, excellent water resistance, solvent resistance, and reliable adhesion
Automatic dispensing equipment
Computer programming, accurate positioning, controllable stroke
The glue line is controllable to prevent spillage and reduce the defect rate.
Complete process
Mature craftsmanship, experienced personnel, effective management system
High quality and efficient production
We are in terms of glue. Factors and solutions that affect the process during the dispensing process:
1. Chemical composition of PUR hot melt adhesive
The amount of certain chemical constituents of PUR hot melt directly affects the viscosity of PUR. From the perspective of product performance, we are committed to the performance improvement of PUR hot melt adhesive (such as viscosity, melting temperature, melt viscosity, initial adhesion, etc.), so choosing a suitable glue is a good start.
2, different bonding materials affect
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 type.
3. How much is 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 is short. When the amount of glue is large, the moisture content of the cured adhesive will be insufficient, and the curing time will be long, which will eventually affect the bonding strength of the structural member.
4, dispensing opening time
The exposure time of the PUR hot melt adhesive on the sample in air must be controlled within 1 min (from dispensing to assembly). In the effective opening time, the bonding is completed to avoid the dryness of the glue line due to the opening time, which causes the wettability of the glue line to be poor, thereby affecting the bonding strength.
5, press
After the PUR hot melt adhesive is assembled, the structural parts must be pressed together for a period of not less than 15 seconds and the pressure should be no less than 3 kg. The purpose is to make the glue form a good adhesive thickness and a wetting effect of the glue between the two bonding faces.
6, ambient temperature and humidity
PUR hot melt adhesive is cured by moisture in the air. The ambient humidity is high and the curing time is short. On the contrary, the long time and high ambient temperature are beneficial to the water participating in the reaction, and the curing time will be shortened accordingly.
7, the surface treatment of the bond
Since the adherent material has a boundary layer such as an oxide layer rust, a chrome plating layer, a phosphating layer, etc., the surface treatment of the adherend will affect the bonding strength. Removing the oil, dust, paint, mold release agent, oxide layer and other substances that affect the surface of the bonded part, which is beneficial to enhance the bonding effect of the PUR hot melt adhesive.
How to improve the quality and efficiency of dispensing work more effectively has become the focus of everyone's attention. Generally speaking, we think it is decided by the following three points:
| High performance structural adhesive | Non-corrosive, high bond strength High initial adhesion, fast curing speed, high-ratio production Excellent aging resistance, weather resistance, excellent water resistance, solvent resistance, and reliable adhesion |
| Automatic dispensing equipment | Computer programming, accurate positioning, controllable stroke The glue line is controllable to prevent spillage and reduce the defect rate. |
| Complete process | Mature craftsmanship, experienced personnel, effective management system High quality and efficient production |
Non-corrosive, high bond strength
High initial adhesion, fast curing speed, high-ratio production
Excellent aging resistance, weather resistance, excellent water resistance, solvent resistance, and reliable adhesion
Automatic dispensing equipment
Computer programming, accurate positioning, controllable stroke
The glue line is controllable to prevent spillage and reduce the defect rate.
Complete process
Mature craftsmanship, experienced personnel, effective management system
High quality and efficient production
We are in terms of glue. Factors and solutions that affect the process during the dispensing process:
1. Chemical composition of PUR hot melt adhesive
The amount of certain chemical constituents of PUR hot melt directly affects the viscosity of PUR. From the perspective of product performance, we are committed to the performance improvement of PUR hot melt adhesive (such as viscosity, melting temperature, melt viscosity, initial adhesion, etc.), so choosing a suitable glue is a good start.
2, different bonding materials affect
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 type.
3. How much is 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 is short. When the amount of glue is large, the moisture content of the cured adhesive will be insufficient, and the curing time will be long, which will eventually affect the bonding strength of the structural member.
4, dispensing opening time
The exposure time of the PUR hot melt adhesive on the sample in air must be controlled within 1 min (from dispensing to assembly). In the effective opening time, the bonding is completed to avoid the dryness of the glue line due to the opening time, which causes the wettability of the glue line to be poor, thereby affecting the bonding strength.
5, press
After the PUR hot melt adhesive is assembled, the structural parts must be pressed together for a period of not less than 15 seconds and the pressure should be no less than 3 kg. The purpose is to make the glue form a good adhesive thickness and a wetting effect of the glue between the two bonding faces.
6, ambient temperature and humidity
PUR hot melt adhesive is cured by moisture in the air. The ambient humidity is high and the curing time is short. On the contrary, the long time and high ambient temperature are beneficial to the water participating in the reaction, and the curing time will be shortened accordingly.
7, the surface treatment of the bond
Since the adherent material has a boundary layer such as an oxide layer rust, a chrome plating layer, a phosphating layer, etc., the surface treatment of the adherend will affect the bonding strength. Removing the oil, dust, paint, mold release agent, oxide layer and other substances that affect the surface of the bonded part, which is beneficial to enhance the bonding effect of the PUR hot melt adhesive.
