In order to ensure that the polyurethane (PU) foaming raw materials for refrigerators maintain good reactivity and performance during storage, the following are standard storage guidelines for raw materials (such as polyether polyols, isocyanates, foaming agents, catalysts, etc.). Reasonable storage environment can not only extend the shelf life of raw materials, but also effectively avoid foaming defects and improve the quality stability of the final product.
1. Temperature control: Store at room temperature to avoid drastic temperature differences
- The recommended storage temperature range is 15°C ~ 30°C to prevent the physical properties of the raw materials from changing due to condensation or high temperature.
- be slowly heated and stirred to a uniform state before use .
- Isocyanates are sensitive to temperature. Prolonged exposure to high temperatures (>35°C) will accelerate their deterioration, thickening, and even premature polymerization.
2. Humidity management: moisture prevention is key
- The relative humidity of the raw material storage environment should be controlled between 10% and 90% .
- Isocyanates (such as MDI) react easily with moisture to generate carbon dioxide, which can cause bulging in the barrel and abnormal expansion of foam. Be sure to ensure a moisture-proof seal.
- Each time the barrel is opened, the lid should be sealed as soon as possible to prevent air and moisture from entering.
3. Avoid light and heat: Keep away from direct sunlight and heat sources
- Polyurethane raw materials should be stored in a cool, ventilated and dry place , away from direct sunlight to prevent component degradation or color change.
- Light can have a particularly negative effect on certain additives (e.g. blowing agents, UV stabilizers).
4. Fire prevention and safety: Managed in accordance with chemical product regulations
- Some raw materials such as isocyanate and foaming agent are flammable to a certain extent and should be kept away from open flames and heat sources .
- The storage area must be equipped with a good ventilation system, leakage emergency treatment equipment and fire-fighting equipment.
- Different types of raw materials should be stored separately and must not be mixed with strong oxidants, acids or water-containing substances.
5. Packaging and transportation precautions
- The original packaging barrel should be well sealed and should be avoided from repeated opening. If necessary, the desiccant should be replaced or nitrogen should be filled to seal it.
- Avoid severe vibration, impact or rolling during transportation, especially for isocyanate, which needs to be handled with care.
- It is recommended to use a pallet to elevate the storage to prevent the bottom of the barrel from directly contacting the ground and absorbing moisture.
6. Shelf life and regular inspection
The shelf life of unopened raw materials is generally 6 to 12 months , subject to the supplier’s label.
- The processed polyurethane foam board should be protected from heavy pressure and friction, and the packaging should be checked regularly for damage, deformation, softening, etc.
- Raw materials that have exceeded their shelf life must be tested on a small scale before use to confirm whether their performance meets the foaming requirements.
Reminder: If the storage environment fluctuates or the isocyanate barrel shows abnormal phenomena such as bulging, darkening of color, precipitation, etc., please stop using it and contact technical personnel for processing.
Proper storage management is the first step to ensure the quality and structural strength of the refrigerator insulation layer. To this end, it is recommended that customers immediately establish a storage record and daily inspection mechanism after the raw materials arrive at the factory to ensure that each barrel of raw materials can be used under optimal conditions.
If you need to obtain storage parameters for specific raw materials (such as MDI, polyether, TCPP, etc.), or develop a personalized raw material storage plan, please contact our technical support team. We will provide professional advice based on your production environment.