The inspection precautions before the use of PUR hot melt adhesive are as follows:
1: First check whether the vacuum state of the PUR hot melt glue package is intact, and stop using it if any air leakage is found;
2: Preheat the glue without tearing off the aluminum foil (label) (usually 5 minutes to 15 minutes), or put the packaged glue in an oven for preheating, it is recommended to control the temperature to 100 ℃;
3: After the PUR glue is taken out from the preheating cylinder, the rubber scabs at the top and tail of the rubber hose must be picked out before the glue can be used;
4: All workpieces should be cleaned with IPA, and ensure that the surface of the workpiece is dry and there is no obvious sign of oil or dust contamination.
The dispensing items of PUR hot melt glue are as follows:
1: The temperature and air pressure of PUR hot melt adhesive dispensing vary with different projects, please consult Xiangao Adhesive Industry technical personnel for details;
2: Stainless steel needles should be used as much as possible, and the inner diameter of the nozzle depends on the specific project;
3: Before installing the nozzle, please discharge a small amount of glue to ensure that the PUR hot melt adhesive can be used normally;
4: The length of the needle tip exposed to the outside of the heater should not exceed 3mm.
Reminder: It is recommended not to exceed the continuous heating time of 4 hours. The same hose should not be heated three times. If the heating time is too long, the back of the hose will be crusted. At this time, the crust can be pierced to reduce the pressure of glue application. (If the glue cannot be removed smoothly during the dispensing process, please refer to: What should I do if the PUR hot melt glue cannot be released normally?)
Product assembly and product bonding and pressing:
The exposure time of the PUR hot melt adhesive on the sample must be controlled within the open time of the PUR hot melt adhesive (from dispensing to assembly).
After the PUR hot melt adhesive is assembled, the sample must be pressed together, the time should not be less than 15 seconds, and the pressure should not be less than 3 kg.
Worker Notes:
Workers must keep the heater on when they leave work to keep the glue in a heated state to avoid repeated heating of the glue; workers must check whether the needle tip is blocked or melted in time when they leave work.
Once the glue has left the required storage environment, unpacked, heated and put into use, it should be used up within 12 hours (calculated from the start of dispensing). If it needs to be extended, it should continue to be used under the condition that there is no obvious change in the viscosity of the glue. If there is a change, it must be replaced immediately.
PUR hot melt adhesive storage conditions:
PUR hot melt adhesive storage temperature: 8~28°C, store in a dry place away from light and avoid excessive air humidity. Do not use products with damaged packaging.
Warm reminder: the above is just an operation guide, not a specification or limitation of this product. Once the glue leaves the required storage conditions and the package is opened, there will be an unpredictable service life depending on its use conditions.
