Storage Conditions
Hot melt adhesives are relatively stable products, but proper storage is essential for maintaining their performance characteristics:
- Temperature: Store at 5-35°C (41-95°F). Avoid extreme heat (which can cause premature aging) and extreme cold (which can cause crystallization in some formulations).
- Humidity: Keep in a dry environment. While hot melts are not water-sensitive in their solid state, moisture on the surface of pellets or sticks can cause foaming when melted.
- Light: Store away from direct sunlight. UV exposure can degrade some adhesive formulations over time.
- Ventilation: Ensure good ventilation in the storage area, although hot melts do not emit VOCs in their solid state.
Shelf Life Management
Most hot melt adhesives have a shelf life of 12-18 months from the date of manufacture when stored properly. To manage shelf life effectively:
- Implement FIFO (First In, First Out) inventory management
- Label incoming stock with receipt dates
- Check the manufacturing date on each bag/box before use
- Do not mix old and new adhesive in the same melt tank
- Inspect adhesive before use: discolored or odorous adhesive should be discarded
Handling Safety
While hot melt adhesives are generally safe to handle, proper precautions are important:
- Wear heat-resistant gloves when handling melted adhesive or working near melt tanks
- Wear safety glasses to protect against splashes during melting
- Use appropriate PPE (gloves, dust mask) when handling powdered or granular adhesives to avoid inhalation of dust
- Clean spills immediately—hot melt adhesive becomes slippery when melted
- Keep the work area free of tripping hazards (hoses, bags, pallets)
Melt Tank Management
Proper melt tank management prevents common production issues:
- Do not overfill the tank—maintain adhesive level between 1/3 and 2/3 capacity
- Set the temperature according to the manufacturer's recommendation, never exceeding the maximum
- Clean the tank every 100-200 operating hours to prevent charring buildup
- Use a tank purge compound when switching between adhesive types
- Never leave adhesive in the tank at temperature for extended periods (overnight, weekends) without reducing the temperature to a standby level (typically 120-130°C)
Waste Reduction
Reducing adhesive waste saves money and is better for the environment:
- Only melt what you need for the current production run
- Collect and reuse clean adhesive trimmings where possible
- Use the right amount of adhesive—more is not always better
- Optimize application patterns to minimize excess
- Properly dispose of cured adhesive waste according to local regulations (most hot melts can be disposed of as non-hazardous waste)