Kunststoffe in der Milchwirtschaft — eine kritische Studie,V. Mitteilung: Zur Reinigung und Desinfektion von Kunststoffoberflächen 1. Teil: Spezielle Gegebenheiten

Plastics in the Dairy Industry — A Critical Study V: Cleansing and Disinfection of Plastic Surface, Part 1: Special Characteristics Plastic articles are suitable for repeated use in direct contact with food-stuffs, provided the former can be maintained properly clean and low in germ-content. Uptil now the plastic surfaces were cleansed empirically, based purely on the experience gathered from conventional materials. The difficulties arising hereby result from the special requirements which the plastics, limited by their specific properties, set on their cleansing solutions and cleaning processes. As against the metals, the plastics do not corrode, however, they are etched easily and are partly not very thermostable. Measurements of angle of contact have shown that the adhesion of fatty impurities on PVC and polyethylene is stronger than the corresponding adhesions of cleansing solutions, hitherto employed for glass and metal surfaces. Soft PVC retains water in contact with cleansing solutions; the extent of liquid retention being dependent on the quantity as well as nature of the plasticizer and on the temperature.