THE THREE PRIME FACTORS IN SUCCESSFUL PACKAGING* By E. C. EM_•Nt•E•, Chief Chemist, Glass & Closure Products, .4rmstrong Cork Company, Lancaster, Pa.. I• THE successful packaging of any material, there are three main factors for the producer to con- sider: the product, the container, and the closure. Although attractive closures, la- bels, wrappings, seals and cartons are important from a sales stand- point, they do not contribute to the keeping qualities of the product. The three major factors are, to repeat, first, the product itself, sec- ond, the container, and third, the closure. The product may be powder, liquid, or solid. It may be neutral or have an acid or alkaline hydrogen- ion concentration. It may contain water, alcohol, the higher alcohols, organic solvents, oils, fats, or waxes, organic or in'organic salts, essential oils, etc., or complex combinations of any of the above. The p.roduct may react with the container or with the closure therefore, great care must be exercised in the choice of these for proper results. The container may be glass, metal, paper, molded material, or a * Presented at the May 15, 1946, Meeting, New York City. speciaJ type not requiring closures, such as cellophane, Vinylitc, Plio- film or other synthetic wrappings. The closure may be a friction fit lid for a metal container, a ground glass stopper, or a plug or stopper type of closure such as corks, screw caps produced from various metals, or molded caps: During the war period, closures were produced from paper, wood. and other available materials. Paper closures have neither the utility nor the attractive appearance of either the molded or metal caps, consequently are not in general use. By far the most generally used closures are those with internal screw threads. Prior to 1919, each cap manufacturer and some closure users designed their own thread contours and designated the number of threads per inch and other dimen- sions. After the First World War, standardization in many fields was considered, and studies were under- taken in the Glass Container Asso- ciation-now the Glass Container Manufacturers Institute--to de- velop standards for the entire glass industry in the various diameters of

THREE PRIME FACTORS IN SUCCESSFUL PACKAGING closures and styles of finishes com- monly manufactured. A number of types were obsoleted and standards set up which have been well ac- cepted by the glass container manu- facturers and the trade. This standardization has enabled the glass manufacturers to work to closer tolerances, and permits a user to buy either closures or containers from two or more sources of supply and be sure that the closures will fit the containers of any manufacturer, or vice versa. The Standardization Committee of G.C.M.I. is still quite active in improving present finishes and approving suggested changes. Screw caps consist of two com- ponent parts, namely, the cap itself and the liner. The caps may be made from metal or from synthetic molding materials. Before the war, metal caps were produced of tinplate, aluminum or terneplate. Some closures were made from brass or nickel-plated brass, though these were not con- sidered "standard" closures f•r the general industry. They do find ex- tensive use in the Toiletties Indus- try. Terneplate consists of steel coated with a lead alloy, and has not been used generally for cosmetic or food purposes, due to the high lead content. Owing to the scarcity of tin during the war, it was necessary that its use be curtailed conse- quently, only highly essential items were permitted the use of tinplate. The closures were produced from black iron and bonderized black iron. Clostires made from sub- stitute materials are subject to rust- ing when exposed to conditions of high humidity or corrosive prepara- tions. The protective coatings, either oleoresinous or synthetic, do not sufficiently protect black iron or bonderized blackplate from rust. Frequently under-film corrosion de- velops, in which the rust develops beneath the protective coating, since moisture-vapor penetrates through the coating. The protective coat- ings adhere better to the bonderized plate than to the plain black iron. It must also be remembered that during the war period raw materials for protective finishes were scarce, and many substitutions had to be made which did lower the quality of the protective finishes. Tinplate, while it will rust under adverse conditions, has stood up very well in general use. During the war, the electro-tinning of plate was developed, whereas, formerly,' the hot-dip practice was used. In this latter method, approximately 11/4 to 11/2 lbs. of tin were applied to a base box of steel plate. By the electro-tinning method, equivalent rust protection can be developed by the use of 8/4 lb. of tin per base box, or somewhat less. When tin again becomes available, electro-tinplate will be u. sed generally for screw caps. Prior to the war, a sizable quan- tity of caps was produced from aluminum, although the cost was somewhat greater than tin. Should aluminum be equivalent in price to tinplate, it will find considerable use in the post-war period. Aluminum will be attacked by alkaline prod- ucts and by certain inorganic salts,