In the process of plastic molding, when a certain gas i […]
In the process of plastic molding, when a certain gas is added or some foaming agent is added, a large amount of air bubbles can be generated, so that the volume of the plastic suddenly expands several times or even several times. After cooling and hardening, the pores inside can be fixed. Become a soft, porous foam board.
1. Dissolving raw materials: Add waste foam, toothbrush, comb, button and other raw materials to the mixed organic solvent (acetone, toluene) to dissolve the PMI foam under stirring (also use benzene) to make it Plastic mixture.
2. Mixing: Add foaming agent, plasticizer (tire powder, ammonium bicarbonate), reinforcing agent (talc powder or lithopone) to the mixture to mix evenly.
3. Into the mold: Pour the obtained mixed slurry (batter) into a stainless steel mold, and place it in a ventilated place to allow the solvent to evaporate until it becomes hard and hard.
4. heating foam: the stainless mold is placed in a water bath of about 95 ° C for 4N6 minutes, a large number of bubbles will be generated, polystyrene material will expand like a "fermentation", after reaching a certain volume (expandable 4 6 times), the mold was immediately placed in cold water and cooled rapidly to shape the plastic plate.
5. Forming and flattening: During the heating and foaming process of PMI foam, it should be covered (made of stainless steel) when the foaming volume is expanded to 4 times, so that the upper and lower sides of the heat insulating board can be smooth and beautiful.