The use of hot melt adhesive requires proper preparation and preheating to ensure the smooth running of the work.
1. Add glue
Add the appropriate amount according to the amount of glue used and the size of the hot melt glue sol pool. During normal use, keep the liquid level range of 35%-80% in the sol pool. If you use a small amount of hot melt adhesive in a single use, you don’t have to add too much. Generally, the liquid level can be controlled at about 50%, otherwise the hot melt adhesive will be repeatedly melted, resulting in waste of electric energy, and under the repeated high temperature of the heating tube, the hot melt adhesive will be partially deformed. Hot melt adhesive melts.
2. Warm up
Solid hot melt adhesives must be preheated before use, and must be preheated to a liquid state before use. The temperature adjustment should not be too high, because the initial melting state is relatively slow, especially for EVA hot melt adhesives. Partial decomposition will occur above 205°C. There are two heating methods for existing equipment, one is oil bath heating; the other is electric hot plate heating. In terms of performance, oil bath heating is better, and its advantage is that the temperature is stable. The market share of direct heating of electric hot plates is relatively high, basically reaching more than 80%. The reason is simple structure and low cost. The carbonization of the melt, especially when the temperature of the melt is too high, has a greater impact in this regard. The preheating time is generally 2 hours, and the central value of the temperature setting is 140~160℃. As the amount of hot melt adhesive increases, the upper and lower temperature limits are often 140°C and 190°C.
