Hot melt adhesive opening hours:
1. The opening time of the hot melt adhesive refers to the longest time for the adhesive material to reach the bonding effect under the specified bonding conditions after the hot melt adhesive is applied.
2. Pore and cure times vary with temperature, ambient temperature, number of coats, bondline thickness, substrate, bond time and strength.
Melt Viscosity (CPS)
The melt viscosity of hot melt adhesives, also known as viscosity, refers to the distance the melt flows at a certain temperature and pressure.
Factors that affect viscosity are:
1. The higher the temperature, the lower the viscosity
2. Polymer molecular weight, high molecular weight, high viscosity
In the effect of melt viscosity on the use of hot melt adhesives, the viscosity level has nothing to do with the viscosity of the hot melt adhesive, and the viscosity has nothing to do with the softening point and melting speed of the hot melt adhesive.
Due to the characteristics of hot melt adhesive products, they can only be used within a certain temperature range. High temperature and low temperature environments can be divided into hot melt adhesives for automotive filter elements. When working in high temperature auto warehouses, the maximum temperature can reach 85 degrees. If the temperature is low At this temperature, the hot melt adhesive will lose its viscosity and the filter will disperse. Such as milk straw glue, the milk produced will be stored in the cold storage, such as hot melt glue and other low temperature resistance performance is not qualified, sticky straw will fall.
The softening point of a hot melt adhesive is the temperature at which the adhesive becomes fluid and has fluidity (the test methods are the general method and the Vicat method). At this point, the hot melt adhesive will be very soft, a little sticky, and some will pull the thread out, but it has not yet reached use temperature.
The reason for the softening point is that the raw materials used are different and the ratio of raw materials is different.