1.Use dry sand 2.No water,no additive 3.Very low pollution 4.Energy ... is a new type plastic technics,and adopt singleness dry sand(no water,bond,tagger),then it is hot up, ... molding,pressurized sand-box,take out the air,so the sand is tighten.the course is a ... airproof mloding technic,we can produce Vacuum airproof mloding and sand molding machine by the basis of uesr request.the company ...