Firstly, both rotational molding and blow molding processes can produce hollow products. However, blow molded hollow products or tube shaped blanks can be blown into a tube film without a mold by using gas pressure to inflate the hot blank closed in the mold. It is commonly used in the production of some packaging containers or tube shaped membranes. Polyethylene is commonly used as the material for hollow blow molding.

    The rotational molding method is similar to the rotational casting method, but the material used is not liquid but sintered dry powder. The production process is also very simple. Put the dry powder into the mold, and then let it rotate around two perpendicular axes. After heating, it will melt evenly on the inner wall of the mold, and after cooling, the hollow product can be removed. In addition to polyethylene, it also uses plastics such as polyamide and cellulose.

    Blow molding may leave a head after removing the blowing tube during production, while rotational molding may also leave a lot of burrs if not cut.