Panel formed of hollow plastic balls containing a fire retardant liquid

摘要

Panels and other objects are formed by blowing hollow bubbles of plastic into a mold and stacking the bubbles in the mold in abutment with each other while the bubbles are tacky to form a mass of bubbles bonded together in a desired contour. The bubbles are formed by blowing successive bursts of compressed air into a mass of plastic material confronting an orifice and cutting the bubble off from the mass of plastic material on the side of the orifice opposite the liquid plastic. A panel for construction purposes is illustrated and includes fire extinguishing means integral with the panel.