An optical mirror finish on chill rolls from Webex yields ultra-smooth and crystal-clear finishes for plastic film and sheet extrusions. Optical mirror finishes normally range from 0.1 to .5 RA, and are considered flawless. Surface finishes are specified to meet specific applications, such as a mirror pocket finish for a high-performance release surface, or a matte finish to produce a textured or opaque film. Proprietary heat transfer software is used to design each chill roll to operate with exacting temperature control of +/-1 degree Fahrenheit.
Such roll superfinishing requires expertise in precision grinding along with specialized grinding and polishing machines. In manufacture, a series of progressively finer stones or grits are used to smooth the roll surface. Eventually all grind lines are removed and the mirror finish results. There are as many variations on finishes as there are products. Webex can produce rolls to match an existing product by analyzing a film sample. Custom chill stand systems are also available.