As a supplier of double walled hot melt adhesive, I've witnessed firsthand the pivotal role this adhesive plays in various industries. Double walled hot melt adhesive is renowned for its strong bonding capabilities, flexibility, and efficiency. However, one factor that can significantly influence its performance is low temperature. In this blog, we'll explore how low temperature affects the performance of double walled hot melt adhesive and what implications this has for our customers.
Physical Properties Changes at Low Temperatures
Viscosity Increase
One of the most immediate effects of low temperature on double walled hot melt adhesive is an increase in viscosity. Viscosity is a measure of a fluid's resistance to flow. As the temperature drops, the molecules in the adhesive slow down, and the intermolecular forces become stronger. This results in a thicker, more viscous adhesive.
For instance, in a typical manufacturing environment, when the temperature falls below the optimal range for our double walled hot melt adhesive, say from 60°C (140°F) to 20°C (68°F), the viscosity can increase by several orders of magnitude. This high - viscosity state makes it more difficult to apply the adhesive evenly. It may not spread smoothly on the surfaces to be bonded, leading to uneven glue lines and potentially weaker bonds.
Hardening and Brittleness
Low temperatures can also cause the double walled hot melt adhesive to harden and become brittle. The adhesive loses its flexibility as the polymer chains within it become more rigid. At extremely low temperatures, such as - 20°C (- 4°F), the adhesive may even crack under stress.
This brittleness is a major concern in applications where the bonded parts are subject to movement or vibration. For example, in automotive interiors, if the double walled hot melt adhesive used to bond trim pieces becomes brittle in cold weather, it may fail to hold the parts together, leading to rattling or detachment.
Bonding Strength Reduction
Poor Wetting
Wetting is the ability of an adhesive to spread over and adhere to a surface. At low temperatures, the high viscosity of the double walled hot melt adhesive impairs its wetting properties. The adhesive may not be able to flow into the microscopic irregularities on the bonding surfaces, reducing the contact area between the adhesive and the substrates.
As a result, the mechanical interlocking that contributes to the bonding strength is weakened. For example, when bonding porous materials like wood or cardboard, the adhesive may not penetrate the pores effectively at low temperatures, resulting in a bond that is much weaker than it would be at the optimal temperature.
Delayed Setting Time
The setting time of double walled hot melt adhesive is also affected by low temperatures. Normally, the adhesive sets quickly after application, allowing for efficient production processes. However, in cold conditions, the chemical reactions that cause the adhesive to solidify are slowed down.
This delayed setting time can be a problem in high - volume manufacturing. For example, in a packaging line, if the adhesive takes too long to set, the packages may not be properly sealed in time, leading to product damage during transit.
Impact on Different Types of Double Walled Hot Melt Adhesives
EVA Hot Melt Adhesive Film
EVA Hot Melt Adhesive Film is a popular type of double walled hot melt adhesive. EVA (Ethylene - Vinyl Acetate) has a relatively low melting point and good flexibility at normal temperatures. But at low temperatures, its performance can be severely affected.
The vinyl acetate content in EVA can influence its low - temperature performance. Adhesives with higher vinyl acetate content tend to have better flexibility at low temperatures, but they may also have lower heat resistance. In cold environments, EVA hot melt adhesive film may become stiffer, and its bonding strength may decrease significantly, especially when bonding materials with different coefficients of thermal expansion.
Environmentally Friendly Hot Melt Adhesive
Environmentally Friendly Hot Melt Adhesive is designed to meet the growing demand for sustainable solutions. These adhesives often use natural polymers or bio - based materials.
However, many of these materials are more sensitive to temperature changes. At low temperatures, the environmentally friendly hot melt adhesive may experience a more pronounced increase in viscosity and a greater loss of flexibility compared to traditional adhesives. This can make it challenging to use in cold climates without proper temperature control.
High Viscosity Hot Melt Adhesive Film
High Viscosity Hot Melt Adhesive Film is already thick at normal temperatures, and low temperatures can exacerbate its high - viscosity nature. The already difficult application process becomes even more cumbersome.
Moreover, the high - viscosity adhesive may not be able to adapt well to the changes in the substrates' dimensions due to temperature variations. This can lead to internal stresses within the bond, which may eventually cause the bond to fail.
Solutions to Mitigate the Effects of Low Temperature
Temperature Control
Maintaining the right temperature during the application and curing process is crucial. This can be achieved through various means, such as using heated applicators, pre - heating the substrates, and controlling the ambient temperature in the production area.
For example, in a cold storage facility where double walled hot melt adhesive is used for palletizing, installing heaters can help keep the adhesive at an optimal temperature. Similarly, using heated glue guns ensures that the adhesive remains fluid and can be applied evenly.
Formulation Adjustment
We, as a supplier, can adjust the formulation of the double walled hot melt adhesive to improve its low - temperature performance. This may involve adding plasticizers to increase flexibility or using polymers with better low - temperature properties.
For instance, incorporating a small amount of a low - melting - point co - polymer into the adhesive formulation can lower the glass transition temperature of the adhesive, making it more flexible at low temperatures.
Conclusion and Call to Action
In conclusion, low temperature has a significant impact on the performance of double walled hot melt adhesive, affecting its physical properties, bonding strength, and application process. Understanding these effects is essential for ensuring the quality and reliability of the bonded products.
As a leading supplier of double walled hot melt adhesive, we are committed to providing high - quality products that can perform well in various environments. We have a team of experts who can help you choose the right adhesive for your specific application and offer solutions to overcome the challenges posed by low temperatures.
If you are in the market for double walled hot melt adhesive or have questions about its performance in cold conditions, we invite you to contact us for a consultation. We look forward to discussing your requirements and finding the best adhesive solutions for your business.
References
- "Handbook of Adhesive Technology" by Skeist, I.
- "Adhesives and Sealants Technology" by Mittal, K. L.
- Industry reports on the performance of hot melt adhesives in different temperature conditions.
