Thermoplastic Elastomer Polyolefin, TPO for short, is another plastics polymer that has recently taken hold in the automotive industry as both plastics manufacturers and end-users fine tune formulation and molding processes. TPO is easily thermoformed (which lowers unit cost) and is designed to be readily recycled at the end of its product life. Another advantage is that TPO does not contain plasticizers (unlike many other thermoplastics), which means that parts retain the same degree of flexibility regardless of temperature. In addition to the automotive industry where TPO is used to create fenders, bumpers, running boards, splashguards, and instrument panel skins; TPO also shows up in applications as diverse as imitation-slate roofing tiles, ATV bodys, and shells for ski boots.

For this TPO automotive component, the task was to trim edges and openings in the part at a minimum rate of 2.2 meters per minute (86 inches/minute). The laser setup for our applications test consisted of a Firestar f400 laser with beam delivery through a set of XY flying optics into a cutting head. The cutting head holds a 101.6 mm (4”) focusing lens with a 150 micron (0.006”) focused spot and a 4.3 mm (0.17”) depth of focus. Nitrogen assist gas at 2.4 bar (35 PSI) is delivered coaxially with the beam, which serves to protect the lens and blow vaporized debris through the cut kerf. The thermoformed TPO, having a consistent thickness of 3.2 mm (0.125”), was cut using 400 watts of power at a cut speed of 3.8 meters per minute (150 inches/minute)—a speed increase of 56% over the original requirement.

This automotive part exhibits cleanly cut edges after trimming operations using 400 watts of power at a cut velocity of 150 inches per minute.