Polyacetal, also called POM or polyoxymethylene, and widely known under the trade name Delrin® is often used for manufacturing lightweight parts to replace heavier metal components. Polyacetal is an engineered thermoplastic polymer that features high wear resistance, high flexure fatigue strength, and excellent dimensional stability. It is easily formed by various molding processes including injection, compression, or blow molding, by extrusion, or by rotational casting.

The requirement for this application is to mark a molded valve body. Because polyacetal produces a slightly contrasting, engraved mark, the identification information is not readily visible (or distracting) to the consumer, but is easily seen on close inspection. The engraved mark is permanent and will not wipe off or smear if exposed to chemicals or cleaners.

Cellulose acetate is a tough thermoplastic material created from processed wood pulp or, in some cases, cotton. Because cellulose acetate is based primarily on wood pulp, this “plastic” is actually a renewable, biodegradable material. Manufacturers of textiles, clothing, film, and filtration products commonly use cellulose acetate singularly or in conjunction with other fibers or additives.

This customer application called for laser cutting 0.13 mm (0.005”) thick cellulose acetate film with a marking head. The FH marking head used a 125 mm lens that provides a 180-micron (0.007”) spot with a 3 mm (0.118”) depth of focus.

Using 25 watts of power at a Velocity of 1651 millimeters per second (65 inches/second), we cleanly cut 30 mm (1.18”) diameter holes in a cycle time of 0.09 seconds per hole. In a web-type application, a single FH head could cut these holes in cellulose acetate film at line speeds up to 50 meters/minute (164 ft/minute), depending on the desired spacing.