How to Identify The Quality of Hot Melt Adhesive?
Published on Feb. 03, 2020
Hot melt adhesive supplier introduces you: There are many quality indicators of hot melt adhesives, special equipment and appropriate testing environment are needed. In the absence of equipment, first of all, look at the appearance of the glue Consistent, with or without air bubbles. Next, melt the glue to make a tape with a width of about 1CM and a thickness of 0.2CM. After cooling, stretch the tape by hand to see if the stretch rate can reach the standard. Whether the strength is sufficient and whether the fracture can maintain the same color. If there are powdery substances, it means that there are too many fillers or uneven mixing, or the filler particles are too large, which will cause a major quality accident. Next, the pellets were stored in a 0 ° C environment, kept for 24 hours, and then taken out. If brittle cracking occurred when struck with a hard object, it showed that the low temperature resistance was poor. Do not put the glue at a temperature of 40 ℃ for a certain period of time. If the glue is soft, self-adhesive or sticky, it means that the softening point of the glue is low. If it belongs to the same grade of product, yellow glue is better than white glue because of its The formula and the process are the same, except that titanium dioxide is added to the white glue.Due to the poor solubility of titanium dioxide, the hardness and viscosity of the white glue are reduced, and it is easy to precipitate, which makes it difficult to clean up heating devices such as preheating barrels. Once deposited on the heating site, It will reduce the heating effect.
New technology and development trend of hot melt adhesive industry
1. Low temperature hot melt adhesive
Low-temperature hot-melt adhesives break through the limits of use of traditional hot-melt adhesives. Its normal operating temperature is only 110 ° C ~ 130 ° C, and the use temperature of low temperature hot melt adhesive is lower than the traditional hot melt adhesive by more than 30 ° C. Compared with traditional hot-melt adhesives, low-temperature hot-melt adhesives have significantly lower viscosity values, ensuring that the coating process requirements are met under low-temperature operating conditions. The direct benefits of low temperature hot melt adhesives are savings in electricity and machine maintenance costs. A large number of practical applications show that the same hot melt adhesive machine, using low temperature hot melt adhesive, can save customers about 15% of electricity costs. And because the low temperature hot melt adhesive has almost no aging phenomena such as skinning and carbon deposition at its normal operating temperature of 110 ° C ~ 130 ° C, the maintenance cost of the machine is greatly reduced. More importantly, the low temperature hot melt adhesive will not burn the PE film.
2. Hydrophilic hot melt adhesive
Traditional hot-melt adhesives are generally hydrophobic. Hydrophilic hot-melt adhesives are made hydrophilic by special formulas. Each application of hydrophilic hot-melt adhesives can give higher added value to products and make product production In the current highly competitive market, manufacturers effectively differentiate their products and ultimately win consumers.
Aging-Resistance Hot Melt Adhesive
3. Other new technologies of hot melt adhesive
In addition to the above aspects, the new technologies of hot melt adhesives include: aging-resistance hot melt adhesive; hot melt adhesives suitable for high frequency spraying; high humidity hot melt adhesives; Melt glue and so on. Oil-resistant hot melt adhesive