Products Finishing

SEP 2013

Products Finishing magazine is the No. 1 industrial finishing publication in the world. We keep our readers informed about the latest news and trends in plating, painting, powder coating, anodizing, electrocoating, parts cleaning, and pretreatment.

Issue link: https://pf.epubxp.com/i/156873

Contents of this Issue

Navigation

Page 58 of 79

PAINTING CLINIC B.R. said, "ABS will be much more likely to crack if not molded at the correct temperature and pressure. The cracks do not show up in the molding process, but later when parts are processed or stressed (often this is when they are painted). They need to slow the process down a little, increase the pressure or time under pressure, and/or increase the temperature at which the part is molded. Molders process parts at as low a temperature as they can, and at as low a pressure as they can, for as short a period of time as possible. Often the problems do not show up until the solvents in the painting process stress the plastic. The cracks are a sign their process is not under control." C.S. said, "You are correct that paint will not improve the crack resistance of ABS. Different kinds of paints degrade plastic impact resistance to one degree or another. The question doesn't address when the cracking occurs. It could be that some environmental exposure like sunlight or chemical resistance is contributing to the cracking. If so, painting would help by protecting the surface. "Other solutions might be to change the gas venting in the mold. Gas trapping can contribute to cracking or poorer impact resistance. Designing the mold itself with ribs might be a solution. Finally they might look at changing materials to a glass-filled ABS or an ABS/PC blend, or go to PC." Thanks for the input, B.R. and C.S. Responses such as yours are always welcome at Painting Clinic. app Bringing you the latest fnishing news, a glossary of fnishing terms, and tools you can use on your shop foor! What's the acid base indicator for phenol red? Can't remember? Look it up on the PF app. Can you combine chlorine hydrogen sulfde? Better be safe and check the PF app for reactive hazards. Do you remember what the plating specifcations are for anodizing electrolytic treatments of magnesium alloys? Don't worry—it's at your fngertips with the PF app. Download the Products Finishing APP @ PFonline.com PRODUCTS FINISHING — pfonline.com 57

Articles in this issue

Links on this page

Archives of this issue

view archives of Products Finishing - SEP 2013