HEAT CLEANING FOR THE COATING INDUSTRY

摘要

Heat cleaning and thermal stripping is not a modern process. Paint line managers have been burning off coatings from material-handling hardware for many years. The term "burn-off" was applied years ago when fixtures were burned out back, in a pile, on the ground. This uncontrolled burning of fixtures caused lots of environmental problems, including smoke, and was a big concern to local fire departments. The heat-cleaning or thermal-stripping oven was developed to serve a dual purpose. First, it solved the smoke and environmental problems present with burning. Second, it provided a controlled process to safely clean material-handling fixtures, racks, trees, and hooks without worry of distortion or damage to the parts being cleaned. During the 1980s rapid changes took place in the coating industry and electrostatic coatings, liquid and powder, gained wide acceptance. These modern coatings tended to be highly resistant to chemical attack requiring strong agents for chemical stripping. They also' required more frequent cleaning to ensure electrical continuity for the electrostatic charge to hold the paint on the component being coated prior to curing. Since the 1980s regulations governing solvent and chemical usage, storage, handling, and disposal have become extremely stringent. These require careful investigation, particularly before expanding liquid stripping operations. Compliance to meet federal and local requirements can be costly. Modern ovens for stripping applications have evolved into sophisticated process cleaning ovens with controls designed for processing a variety of materials found in the coating industry today. They are designed to not only clean material-handling hardware but to also strip reject parts, allowing them to be recycled through the coating process (see Fig. 1).