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Hot melt adhesive particles are a type of thermoplastic adhesive. At room temperature, it is a solid state, but due to the influence of temperature increase, it will flow softly and reach a liquid state at high temperatures. After being applied to the surface of the material, the hot melt adhesive will lose heat and return to a solid state. This indicates that temperature is a direct factor affecting the viscosity, elasticity, ductility/stiffness, adhesion, and usage of hot melt adhesive particles.
Next, let’s analyze the relationship between temperature and hot melt adhesive in order to effectively apply hot melt adhesive and ensure high safety.
1、 The impact on adhesive strength
Different types of hot melt adhesive particles will have varying degrees of temperature resistance, but in principle, as the temperature increases, the strength of the hot melt adhesive will decrease because it loses its ability to maintain the two surfaces of the materials connected together.
On the other hand, low temperatures usually do not have adverse effects on the durability of hot melt adhesives. Usually, they make the glue harder and reduce its flexibility.
2、 The impact on hardness, thermal stability, and safety
For hot melt adhesive particles, after being coated on the surface of the material and restored to a solid state, the adhesive actually promotes its adhesion.
Hardness:Influenced by temperature. High temperature can reduce the hardness or durability of the adhesive. If the adhesive is too loose during pasting, it can cause the adhesive to overflow, resulting in aesthetic damage to the finished product and even causing burns during operation.
Thermal stability:When the adhesive is heated above its normal operating temperature, its chemical structure will be damaged or altered, resulting in a decrease in the elasticity of the adhesive.. This also leads to cracking or damage, as well as loss of inherent adhesive strength. This is also known as thermal degradation. Therefore, it is necessary to accurately understand and apply the specifications of the adhesive in order to use it correctly and effectively on the equipment line in the factory.
Safety issue:Glue is used in a molten state, which requires operators to equip necessary protective equipment and receive training on basic production safety procedures to prevent and reduce accidental injuries or accidents..
3、 The Effect of Temperature on Viscosity
Viscosity is the ability to resist flow resistance. The higher the temperature applied to the hot melt adhesive, the lower the viscosity of the liquid.
If the glue is too thin, it will be difficult to fix the glue on the bonding surface, and the glue will overflow the edges and cause burns, and the drying time will be slow. For positioning, we should use glue with moderate or high viscosity (which helps to fix quickly).
If hot melt adhesive is used at very high viscosity (low temperature), the glue will dry quickly before it can adhere to the surface of the second material, resulting in a decrease in bonding effect. In addition, if the operating temperature is too low, the operation will slow down, resulting in a decrease in production efficiency.
Recommended solution:Use glue with viscosity and working temperature suitable for production line speed to maximize productivity..
If you are unsure about the suitability and standards of the glue on the production line, please contactSunlife Hot Melt Adhesivefor advice and solutions to the problem.
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