Technological process of polyurethane rigid foam plastic spray

2． Technological process of spray
2.1 Prepare raw material, spray foaming machine and products waiting for spray
2.2 Prepare for the protection
2.3 Measure the temperature and density of materials
2.4 Filtrate materials and put them into tanks.
2.5 Return current
2.6 Make a trial spray
1) prepare 3~5 pieces of aluminum board with parting agent whose area is about 1m2；
2) the operator should wear a face guard whose thickness should be above 40mm.
3) regualte the pressure of compressed air and observe the pulverization condition of materials.
2.7 Measure the foam capability of the sample.
Choose a normal foam plastic board and make a sample to measure the density, pressive strength
under normal temperature and close cell rate.
2.8 Spray products
If the trial spray is up to standard, spray products.
2.9 Measure the foam capability of the sample.
After the spray, spray another piece of foam plastic, measure the density, pressive strength
under normal temperature and close cell rate.
2.10 Clean foaming machine
2.11 Seal up for keeping
3. Quality control
3.1 All raw materials should have certificates of inspection
3.2 Store the raw material under airy, dry, sunproof and preventing frostbite condition. Reexamine the raw materials before store according to the technical condition. For those with warranty period, please reaxamine on schedule.
3.3 Screw down the cover after taking out materials. All special-purpose wares and containers must be dry nad clean.
3.4 Measure the temperature of A material, which should be 15-17℃, and density, which should be 1.20-1.24g/cm3.
3.5 Measure the temperature of B material, which should be 20-23℃, and density, which should be 1.22-1.25g/cm3.
3.6 When spraying foam plastic, the environment temperature should be above 20℃ and the relative humidity should be below 60%.
3.7 The surface for spray should be clean, dry and without oil stain.
3.8 When spraying, the gun movement frequency should correspond to the circumgyrate speed of the product. when one time spray width is 700-800mm and the distance from gun to the surface is about 600mm, the thickness of foam plastic is moderate. Regulate them according to the actual quality of spray foam plastic.
3.9 Please observe the actual spray condition, if a group of materials is near use up, stop spray immediately.
3.10 The processed foam plastic should be transfer to the next working procedure in 24 hours.
4. Storage and transportation
Storage condition: the temperature should be below 40℃, and the relative humidity should be below 70%.