What is the impact of the softening point temperature of hot melt adhesive particles? 4 dimensions that must be read for selection

What is the softening point

The softening point ishot melt adhesive pelletsThe temperature at which a solid state transitions to a soft plastic state is typically measured using the globe method. It directly affects the heat resistance, curing speed, operating temperature window, and storage requirements of the adhesive particles. When selecting, looking at the softening point is like looking at the wear resistance index of a tire – it is one of the core indicators.

The four influencing dimensions of softening point height

• heat resistanceThe higher the softening point, the less likely the adhesive layer is to soften and deform in high temperature environments. Sealed cardboard boxes for summer transportation should be selected with rubber particles with a softening point greater than 90 ℃.
• curing speedColloidal particles with a high softening point begin to solidify when cooled below the softening point, and the curing speed is usually faster, making them suitable for high-speed production lines.
• Operating temperature windowA high softening point means that the coating temperature needs to be correspondingly increased (usually coating temperature=softening point+60-80 ℃), resulting in higher energy consumption and equipment requirements.
• storage stability Low softening point rubber particles（<70℃）在夏季仓储中容易软化结块，需控温储存。

Reference for softening points in different application scenarios

Sunlife hot melt adhesive granules provide a product line with multiple softening point gradients ranging from 70-105 ℃, covering various application scenarios.

Frequently Asked Questions (FAQ)

Q: Is softening point and melting temperature the same thing?

A: No, it’s not. The softening point is the temperature at which the rubber particles begin to soften, and the melting temperature is the temperature at which they completely become liquid, usually 20-40 ℃ higher than the softening point.

Q: Is the higher the softening point, the stronger the adhesion?

A: Not necessarily. The adhesive strength mainly depends on the wetting and cohesive force of the adhesive solution on the adhered surface, and the softening point only affects the heat resistance and curing speed.