DRYING a t low temperature with precise control of humidity
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e NIAGARA Aero“ HEAT EXCHANGER gives you precise control over temperature, over the results of your process, over the quality of your product. You save cooling water cost, trouble, and the results of “heat pollution.” The heat passes outdoors in the air stream. Or you may add heat for warm-up period. Improved panel casing construction, cleanable tube bundles, make maintenance easy and inexpensive. Write for BiilZetift 161
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LETTERS
Polymer Coatings us. Protective Coatings
Sir : I n the preparation of a n Annual Review on Coatings (August issue), Dr. Parker and I have addressed ourselves to the task of reporting by assessment of the changes in the disciplines of coatings. This obviously requires more time and consultation than is the case of a cold, traditional, card index type of survey. I n this connection, we also questioned others regarding the proper descriptive title. We weighed several alternate adjectives such as organic, protective, decorative, chemical, industrial, trade, synthetic, ceramic, and simply Paint. This article was submitted and the galley proof indicated our choice of title as Polymer Coatings. This would seem to point to the common denominator of maximum inclusion and definitive description of these products historically regarded as paints. Others are either incorrect or restrictive. We defend this choice in terms of what seems to be a n ‘unintentional slight in a n excellent recent descriptive book for the educated layman, “Giant Molecules,” edited by a recognized authority on high polymers. The history and science of the principal categories of high polymers are related, in this publication, to products of commerce such as tires, synthetic fibers, molded plastics, cellulosics, gunpowder, stretch garments, synthetic leather, adhesives, foams, and so forth.
Circle NO. 17 on Readers’ Service Card
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INDUSTRIAL A N D ENGINEERIN
C H EMlST R Y
While not entirely omitted, coatings are not given equal space, nor is this end use set apart with the emphasis we feel it deserves. I n terms of one ultimate measure, the industry represented by our article produces $23/8 billion of product. I n terms of science, the technological competence required is almost identical and therefore equal to that concerned with films, elastomers, fibers, and rubbers. I n terms of glamor, the esthetic function of an automotive topcoat is not to be judged less than that of, for example, a girdle. I n terms of durability and service, coatings have advanced to the range of 20 years which is probably longer (in terms of constant exposure to climatic conditions) than most other polymers. We therefore confirm our contenAND ENGINEERtion that II~DUSTRIAL ING CHEMISTRY should take the leadership in identifying this Annual Review as Polymer Coatings which in every sense is inclusive, correct, and justified. Your choice of ‘(Protective” locks out the decorative types which represent about 50% of the market and the technology.
H. L. GERHART PPG INDUSTRIES PITTSBURGH, PA.
EDITOR’SNOTE: Next year we shall face our internal gremlins and print this fine review under “Polymer Coatings” as we should have for the past two years.
