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The coating of plastics has occupied the attention of polymer chemists for the past 30 years. Several problems are immediately obvious. If the coating is a hard resistant thermoset like a baked phenolic, it provides a surface to which every few substances will adhere: Two generations ago all telephones were black for this reason. If on the other hand the polymer is thermoplastic, adhesion is not necessarily a problem but solvents are, since the solvent in the coating can erode the polymer's surface. Plastic surfaces require coating for a number of reasons and this has caused imaginative chemists to devise new coatings and new coating techniques to meet the challenges. Some plastics require coatings simply for decoration. Some require coatings in order to protect the surfaces. This is particularly true in the electronics area. The need for coatings for plastics has been accelerated by the desire of the automotive industry to replace metal with polymers. If the plastic is part of the automobile body it must be coated to match perfectly the coated metal part. Reaction injection moulding (RIM) is providing a means for supplying the automotive industry with large parts such as bumpers, fascias, and in the not too far future doors and hoods. Naturally the coatings on these must duplicate precisely the coating on the metal portions of the car.

From November 29 to December 2 the Empire Hall at Olympia, London, will be given over to what will probably be the world's largest display of products, processes and services for use in the prevention or limitation of corrosion. Over 120 stands will be shared by 94 exhibitors, each contributing in some way or in many ways to this cause. The extensive preview in the following pages is divided into sections. However, the grouping is general and reflects only one aspect of a company's activities. Therefore a complete examination of items is recommended.

Geigy Co. Ltd. Stand 75. Diversified application of benzotriazole as a corrosion inhibitor specifically for copper and its alloys is the main theme of Geigy's stand.

A new area for the maintenance coatings specialist is found in nuclear installations where coatings are necessary which are not contaminated by radioactive materials or which are readily cleaned if there is suspicion of contamination. The testing of coatings for nuclear containment has been discussed in an article by Burger (Metal Finishing, May, 1982, p. 127). Such coatings, the author points out, must be able to withstand exposure to high humidities and, at the same time, exposure to radiation dosage. In addition, the coatings must be sufficiently durable to withstand the conditions which would be anticipated during an accident. To meet these challenges provides a new opportunity for coatings chemists. A bibliography related to testing of nuclear coatings is listed by the author, and from these he concludes that the most significant are the Design Basis Accident or DBA test. This is a test to tell whether the coating will stand up if, in fact, there is an accident. The second test relates to irradiation, and the third to decontamination factors. These are described in detail by the author. He points out that a coating that passes these tests will meet the 40‐year expected life within a nuclear power containment facility.

I am delighted that the fifth Corrosion and Metal Finishing Exhibition has been brought to Leeds and I congratulate the sponsors and exhibitors on their decision to stage this Exhibition in the heart of the industrial north.

With present‐day moulding and extrusion techniques there is a wide range of articles that can be made from solid plastics and there is an ever‐increasing market for these products in industry and the home. Despite the attractive finish of these plastics articles and their ability to withstand corrosion and mechanical damage, there are objections to the use of the solid material for some applications. From an engineering point of view, there are difficulties of rigidity and mechanical strength, whilst economy also rules out the use of solid plastics in many cases, since, whilst it may be possible to mass‐produce large quantities of moulded plastics articles for domestic use, where there is a very large market potential, it is another thing to produce small runs of specialised engineering products economically. For these reasons there is an ever‐increasing demand for plastics finishes to both standard and purpose made metal goods either to protect the base metal or to produce an attractive finish.

The end of this month will see Britain's biggest display of products and processes designed to prevent the onset of corrosion in all its forms. At the Royal Horticultural Society's New Hall, in Westminster, there will be over a hundred stands on view to visitors to the Exhibition which will run from April 27 to 30 inclusive. Here is C.T.'s exclusive preview. Stand descriptions are grouped under various headings, but the fact that a firm's exhibits are described under one heading does not necessarily mean that its interests are confined solely to that group of products. The grouping of exhibitors in this preview is merely intended to facilitate visitors who are interested in particular aspects of corrosion prevention.

Articles elsewhere in this issue survey the main types of plastics coatings and processes used for protecting steel against corrosion. As a result of the introduction of these an industry of considerable size has now grown up, composed of firms specialising in the application of plastics coatings both in the factory and in the field. In the following pages we report the activities of a number of such firms, drawing attention to any new developments in products, equipment and techniques, and giving examples of work undertaken by them.

This assessment of the range of metals and plastics used in anti‐corrosive applications gives a guide to the reader who is uncertain of the type of spray coating most suited to his needs. After reviewing the development of spraying, the author compares the advantages and disadvantages of aluminium, zinc, tin and certain alloys, and follows with a comparison of metals and plastics. Lastly, polythene, superpolyamides, polythene polysulphide, PTFE and PTFCE are reviewed.