Continuous application of chemicals

摘要

This review has considered the machine components constructed and assembled to form chemical applicators. Most modern applicators for dyeing and finishing consist of two bowl mangles and are usually justified and purchased for a small range of fabrics of similar width rather than as a general treatment machine. The greatest changes to these machines have arisen from short run, just-in-time production. This has led to rapid rinsing, and rapid colour change designs using small volumes of treatment liquor to minimise batch change over time and waste. An interest in applicators giving high pick-up ( > 120%) has developed, particularly in the preparation sector, as a means of reducing chemical concentrations, chemical damage and process steps. The undriven roller, usually the top roller, is always rubber covered and this cover is probably a nitrile elastomer. In a washer or finishing mangle, this covered bowl will often run against an uncovered metal roller which used to be stainless steel but is now, more usually, mild steel covered in vulcanite in order to minimise cost. This pairing of bowl types in an important criterion of mangle selection. Many of the problems of second hand mangle purchase arise from poor bowl pairing. Most mangles for dyeing have two identical rubber covered, special bowls, such as swimming or Bicoflex rollers.