Rigid polyurethane composite materials are divided into isocyanate and composite polyether Components: commonly known as black material and white material. After the two are stirred and mixed in proportion, a polymerization reaction occurs to form a rigid polyurethane foam with an independent closed-cell structure, which is an ideal organic low-temperature heat insulation material.
1. Storage
The storage of isocyanate (commonly known as black material) and combined polyether (commonly known as white material) must be in a sealed container to isolate air and prevent moisture absorption.
The barrel of isocyanate and polyether combination should not be exposed to the sun. It must be kept away from heat sources and placed in a cool and dry place. If the barrel is placed upright, there should be no water on the lid! The lid must be tightly closed immediately after each use to prevent water vapor and impurities from entering the barrel and affecting the quality. If two or more grades are used to combine polyether, they should be stacked according to grades and have obvious signs. The combined polyether with common flame retardant should not be stored for too long, and must be used on the same day of preparation, otherwise it will easily cause deterioration and affect the foaming quality. For details, please contact our technical service department.
2. Operation
When operating isocyanate and combined polyether, you must wear protective glasses, work clothes and work caps; you should wear clean rubber gloves when operating isocyanate. The working environment must be well ventilated, clean and hygienic. When the ambient temperature is high, the foaming agent in the combined polyether will partially vaporize and generate pressure, so the exhaust cover should be opened first to discharge the gas and release the pressure, and then open the barrel cover. When the foam has flame retardant requirements (note: self-extinguishing after leaving the fire), additive flame retardants can be used. The amount of ordinary flame retardants added is 15-20% of the weight of the white material, and the flame retardant must be stirred when added to the white material. Foaming can only be carried out after uniformity.
For the ratio of black and white materials, please refer to the combined polyether technical information leaflet of the relevant model. Customers who use flame retardants should pay attention to the calculation of the ratio of white materials after adding flame retardants. Flame retardants should be included. When the material ratio is 1:1, if 100kg of white material is added with 15kg of flame retardant, the amount of black material used is 115kg.
When manual foaming operation, accurately weigh the black and white materials according to the proportion and pour them into the container at the same time, stir with a stirrer above 2000 rpm for 8-10 seconds, pour into the mold for foaming, and the demoulding time depends on the product Requirements, foam thickness, etc. are specific.