for this purpose during tfcie war. Other adhesives, ordinarily more expensive and used only for special purposes, are animal glues, casein and soya protein, p h e n o l and
r&caaoùta RICHARD \Y. LAHEY Cost Only Problem in Container Production Inroads into the supply of o u r pulp wood are forcing consideration of certain species of hardwoods hitherto unused. New techniques have enabled p u l p pro ducers to use greater quantities of these hardwoods with success. The use of bagasse, canes, and such annuals a s flax,
These excerpts are from an address made by W. F. Gillespie, Gaylord Container Co., at a recent me ding of the Packaging Engineers' Associa tion in Chicago, III., ana published in the TAPPl Bulletin.
ramie, and even cornstalks is being given serious consideration. T h e s t a n d a r d pro cedures for producing pulps are mechanical and chemical (sulfite, sulfate, a n d soda processes), but in t h e future we may expect new methods and new applications of standard methods t o t h e new species. The growth of t h e plastics industry has made available to the paper and board
Tabic I
producer a very large n u m b e r of materials suited to provide p a p e r with new a n d de sirable qualities. During the war this work received the a t t e n t i o n of numerous investigators and, as a result, m a n y new treatments were developed. Properties of board desired b y box makers are ob tained a t least in part by application of a wide variety of materials b y the processes listed in Table I. Λ large number of materials is available for this purpose. T a b l e II shows the more important requirements a n d some of the materials which are used t o provide these properties. In addition to the a b o v e , adhesives of various types are of considerable impor tance in the fabrication of these containers. The most common are silicate and starches. H e a v y types of silicates are provided by mixing with clay. Vegetable proteins, phenolic resins, and aluminum chloride combinations have been used for special purposes. Aluminum chloride is generally added to v the board in i t s manu facture, usually b y a calender application. Starches are sometimes combined with animal glues, asphalt emulsions, and urea formaldehyde resins. Asphalt was used
PROMPT DELIVERY HERCULES
STANDARD
MKTHODS OK P R O D U C I N G SIRED PROPERTIES
DE
Solutions—internal, coating, calenders, size press Emulsions—Internal, coaling, calen ders, size press Hot Melts—Laminant, coating Impregnations—Emulsions, hot melts, solutions Laminations Re-enforcing—Cloth, fibers (hemp, sisal) metals, synthetic fibers (glass, etc.) urea formaldehyde resins, cellulose ester products, alkyd and acrylic resins, polystyrene, chlorinated rubber, and synthetic rubber. The box manufacturer with new liners, new corrugating media, new t r e a t m e n t s , a n d new adhesives has available t h e m a T a b l e II RESISTANCE TO:—
Water—Internal sizing—rosin, wax, as phalt, silicones Surface—wax, starches, films, lac quers, polystyrene, acrylic Grease—Cellulose derivatives, poly vinyls, zein, polyamides, urea for maldehyde, polystyrene, polybutene, casein Scuffing—Vinyl copolymers, zein, var nishes, enamels (wet), mel amine, and urea Stiffness—Phenolics, silicates Tear—Re-enforcing media, vinyl, acrylic, alkyds (wet), melamine, and urea Wet Strength—Melnminc and urea formaldehyde Thermoplastic Sea-Is—Polyamides, acrylics, polybutene, polyvinyls, polyvinylidene Pressure Seals—Rubbers. vinyls, acrylics Finish—Starches, casein, wax, cellulose terials to produce almost any t y p e of box desired. Cost i s the only problem. T h e production of glossy, lustrous coatings, bet t e r printability, greatly increased wearing qualities, flexibility, or rigidity as desired is possible.
CARBOY BOXES
Saran Film 517 Cap Liner Material
NATIONAL BOX & LUMBER COMPANY 3680
CHEMICAL
Research a n d technical experiments during t h e past few months indicate t h a t the new Saran Film 517 is adaptable for use a s cap liner materia,!. Toughness of the film, together with its high resistance to chemicals and its low moisture transmission, prompted t h e experiments. .Saran Film 517 is claimed t o have been successfully laminated t o various t y p e s of backing materials b y several commercial cap liner houses and is immediately available, T h e Dow Cliemical Co. re ported.
AND
ENGINEERINO
NEWS
