A new rotary trimmer reduces the height and material required for traditional double-ring domes on PET bottles. The Lite Dome from Belvac Production Machinery Inc., Lynchburg, Va., reportedly can reduce the weight of wide-mouth PET containers and cut scrap by up to 30%.
A sawtooth moil rotation guide forces the container to rotate inside the starwheel pocket from the top of the dome. This contrasts with the traditional linear trimming process which uses the gap or space between the rings of the dome to hold the container. Bottles now can be designed with less waste material in the dome and preforms can be produced with less material to reduce cost. The technology is also adaptable to containers of HDPE, PP, and multilayer structures.