Evaluation of hot melt adhesive properties Part A

Melt viscosity (or melt index)

This is a performance indicator that reflects the flow properties of hot melt adhesives. It is direct affecting the applicability, wettability and permeability of the glue to the adherend.It also has an effect on the drawing phenomenon of the glue. Therefore the melt viscosity is determined to melt an important basis for the fusion coating process. Melt viscosity is closely related to temperature correlation, it grows with decreasing temperature, so it must be in one determined at a constant temperature.

Generally under the average hot melt temperature (190 + 2 ° C).The measurement was carried out. Low melt viscosity hot melt adhesive can be used directly in rotary.The viscometer was measured. The measurement method is: pre-melting the hot melt 500ml of the rubber sample is placed in the drum of the viscometer to determine the temperature.Hold at 190+2°C for 5min, let the rotor rotate for 30-60s, read number. For dry high melt viscosity hot melt adhesives, usually for the determination of hot melt.The number is measured by a special melt index meter. test methods is: Pour 190+0.4C molten glue into the drum of the analyzer.Then press it with a punch with a weight of 2160+10g and measure it at 10min.The number of grams of the inner hole is squeezed out of the small hole at the bottom of the drum number.

In order to obtain a good bonding effect, it should be more of a kind of glued material.Select the appropriate melt viscosity (or melting) for the shape of the bonding surface Index of hot melt adhesive.