Custom Chromium Finishes
Roll Technology specializes in precision custom hard chromium plating and finishing of web-based converting rolls, providing a full range of surface finishes including flawless optical mirror, textured satin, dull gray matte and commercial polished finishes. With over 45 years of experience, we have the expertise to provide the finish required for your application to the tightest tolerances. Our staff will assist you in determining which finish meets your requirements to maximize your equipment’s performance and produce consistent, high quality end products.
Hard chromium is used to finish web-based converting rolls due to its hardness (70 Rc) and ability to be precision ground to the most exacting tolerances. It is an ideal material for optical and mirror finishes. Chromium is corrosion and high heat resistant, providing reliable performance in high volume, high wear, and high temperature environments. Various process steps including precision roll grinding, stone polishing, abrasive film polishing, grit blasting, and shot peening are among those used to finish rolls to the required surface finish.
• Optical Surface Finish - Optical finishes are flawless, with no blemishes or marks. Rolls with optical finishes are used to manufacture precision films such as LCD protective screen film, plastic sheeting, and clear thin films used for packaging and electronics. The surface finish is measured below 1 Ra, down to 0.2 Ra.
Roll Technology is one of the few companies worldwide that can deliver consistent, exacting optical surface finishes.
• Commercial Mirror Surface Finish - Used for coating, laminating, and printing applications, rolls with a mirror finish are smooth, with no surface defects. The rolls are shiny and reflective, but do not have Optical characteristics. The surface finish typically is specified to 4 Ra or better.
• Polished Surface Finish - Polished rolls are used for applications that do not require a high degree of luster, but need to be smooth and uniform, servicing applications such as paper products, textiles, and certain initial processing equipment. The rolls have a smooth surface, but may contain small scratches not completely removed during the process. The surface finish is typically specified to 16 Ra or better.
• Grind Surface Finish - Rolls surfaces generate utilizing a grinding wheel are generally are duller in appearance with often a higher roughness than other finishes. They are used for stamping, embossing, or other applications. The surface finish is typically specified at 32 Ra or better.
• Matte Surface Finish – Matte finished rolls have a dull, gray surface generated by grit blasting INTO a hard chromium plated deposit. The resulting peaks and valleys in the roll surface allow air between the roll and the product, so the product does not stick to the roll. They are used to impart a surface finish for non-gloss products. Most matte finishes can be specified in 3 main categories: Light Matte (20-40 Ra), Medium Matte (40-60 Ra) or Heavy Matte (over 60 Ra).
• Satin Surface Finish - Satin finishes produce dull, textured surfaces generated by grit blasting the base metal of the roll body then depositing a thin layer of chrome (generally .001”-.0015” thick). The silvery toned chromium plated surface feels slick to the touch while the surface retains the roughness of the blasted base metal, allowing for snag-free processing coupled with required roughness. These rolls are used for textile and yarn processing, and textured products. The final surface finish can range from 20 Ra to over 300 Ra, depending upon the application and how rough the roll needs to be.
At Roll Technology, we offer expert custom finishing and precision roll grinding for all types of industrial roll applications, including coating rolls, heat transfer rolls, calendar rolls, laminating rolls, slitting rolls, and various web process rolls. Call us today to find out more about how we can help with your roll applications and talk with our Director of Sales/Marketing (David Johnston), our Executive Vice President (Greg Haley) or our President (Lew Walker).