Dry roof material structure is generally fabric/rubber powder/glass fiber /PU hard foam board/rubber powder/glass fiber/non-woven fabric.
Wet roof material structure is generally fabric/glue/glass fiber /PU hard foam board/glue/glass fiber/non-woven fabric.
Dry and wet roof mechanical properties are basically similar, dry process has the advantages of high efficiency and environmental protection, dry roof sensory slightly full; Wet process requires two sets of molds, secondary molding, stable shape, high efficiency, wet process usually uses solvent based adhesive, production process emissions of a large number of organic solvents environmental protection is not as good as dry method.
General dry PU composite board in the middle of the adhesive: HDPE hot melt powder (domestic), EAA hot melt film (foreign).
The advantages and disadvantages of the two: rubber powder processing environment is poor dust, and in the process of powder is easy to appear uneven phenomenon such as agglutination, the composite ceiling sound-absorption is also worse than the film, because PU bubbles are blocked by rubber powder particles; Film defect is not a very good bonding glass fiber layer (everyone knows a lot of small film general melt index glue powder, so the less liquid is not easy to penetrate the glass fiber layer), so use the film in general is the use of glass fiber mat, also have the use of glass fiber cloth, glass fiber powder + + non-woven composite compound cloth first) cost is higher, its forming process: PU foam and glass fiber, rubber powder, non-woven composite PU composite board, and then heated with the fabric composite in the mold into a ceiling, process characteristics: cold mold hot material, hot sol film, is actually polyethylene plastic film. Advantages: simple process, uniform surface, low cost.
Why does dry law exist? The reason is very simple, the dry mold cost is much lower than the wet method, which is an important reason to choose. Second, there are equipment limitations. In general, the upgrading of equipment in enterprises is based on the condition of the original equipment, so the existence of dry method is inevitable.
Wet roof coating is divided into two times, the first time in the skeleton forming, the polyurethane adhesive and water proportionally evenly sprayed on PU board, and then non-woven cloth, glass fiber cloth and other strengthening material layer laid together, hot setting molding. The second time in the fabric composite, after forming the skeleton spray glue, and then on the fabric. Process features: hot mold cold material.