The dilution of heat transfer hot melt glue needs to select solvents according to the specific ingredients and process requirements. Common dilution solvents include cyclohexanone, xylene, toluene, isoparaffin solvents (such as ISOPAR-M) and alcohol solvents (such as ethanol and methanol). The following is a specific analysis:
1. Common dilution solvents
Cyclohexanone and xylene:
Cyclohexanone and xylene are commonly used dilution solvents in thermal transfer hot melt adhesive. They have good solubility and can effectively dilute the hot melt adhesive to a viscosity suitable for coating.
When using cyclohexanone and xylene, it is necessary to pay attention to their volatility and toxicity, ensure that they are operated in a well-ventilated environment, and take necessary safety precautions.
Toluene:
Toluene is also a commonly used dilution solvent, especially in certain specific thermal transfer hot melt adhesive formulas.
Similar to cyclohexanone and xylene, toluene also has certain volatility and toxicity, and should be used with caution.
Isoparaffin solvents (such as ISOPAR-M):
Isoparaffin solvents have the advantages of moderate evaporation rate, strong solubility, and good environmental protection.
It can make the pigment in the ink fully dispersed and evenly attached to the transfer medium, improving the quality and efficiency of thermal transfer.
For thermal transfer processes that pursue high quality and environmental protection, isoparaffin solvents are a good choice.
Alcohol solvents (such as ethanol, methanol):
Alcohol solvents may also be used as diluents in certain specific hot melt adhesive systems.
They usually have lower toxicity and better environmental protection, but the solubility may be relatively weak and need to be adjusted according to the specific formula.
2. Considerations for selecting solvents
Solubility: The solvent must be able to effectively dissolve the hot melt adhesive to achieve a viscosity suitable for coating.
Volatility: The volatility of the solvent should be moderate, ensuring that it can evaporate quickly during the coating process, and avoiding problems such as uneven coating or bubbles caused by excessive evaporation.
Toxicity: The toxicity of the solvent should be as low as possible to ensure the health and safety of the operator.
Environmental protection: With the improvement of environmental awareness, it has become a trend to choose solvents with good environmental protection.