The machine has been designed to cut shapes in a stack of precut PVB sheets. It has been designed to eliminate the need for trimming of the excess PVB which is typically required when assembling windshields with square or stretcher-cut blanks. This typically requires 2 men, for each shift of production. The machine is able to cut the vinyl to a tight tolerance, wherein trimming after assembly is not required. A small amount of excess (1-2mm), depending on the customer, is usually allowed for operator assembly positioning accuracy variation. Nominally speaking the machine will cut enough parts in one shift, for an entire 24 hours worth of assembly production, resulting in a possible savings of 6 trimmers, less one man to operate the PVB cutting machine.
In the past, die cut machines have been used to limited success. The drawbacks of the die cut machines are obvious: lack of flexibility, die costs (initial, repair, and storage), yield loss due to die wear, safety hazard, etc. With the CNC machine proposed here ultimate flexibility is provided. Depending on how production is scheduled, the shape of the vinyl can be adjusted as required to compensate for additional PVB snapback on stretched vinyl, for bend depth variations, etc. As the customer gets more adept at running the process, vinyl savings can be realized by reducing the amount of scrap.