"Bruce Sterling - Superglue" - читать интересную книгу автора (Sterling Bruce)are even more indebted to glue; modern microelectronic assembly
would be impossible without it. Glue dominates the modern packaging industry. Glue also has a strong presence in automobiles, aerospace, electronics, dentistry, medicine, and household appliances of all kinds. Glue infiltrates grocery bags, envelopes, books, magazines, labels, paper cups, and cardboard boxes; there are five different kinds of glue in a common filtered cigarette. Glue lurks invisibly in the structure of our shelters, in ceramic tiling, carpets, counter tops, gutters, wall siding, ceiling panels and floor linoleum. It's in furniture, cooking utensils, and cosmetics. This galaxy of applications doesn't even count the vast modern spooling mileage of adhesive tapes: package tape, industrial tape, surgical tape, masking tape, electrical tape, duct tape, plumbing tape, and much, much more. Glue is a major industrial industry and has been growing at twice the rate of GNP for many years, as adhesives leak and stick into areas formerly dominated by other fasteners. Glues also create new markets all their own, such as Post-it Notes (first premiered in April 1980, and now omnipresent in over 350 varieties). The global glue industry is estimated to produce about twelve billion pounds of adhesives every year. Adhesion is a $13 billion market in which every major national economy has a stake. The Adhesives Age andSAMPE Journal; its own trade groups, like the Adhesives Manufacturers Association, The Adhesion Society, and the Adhesives and Sealant Council; and its own seminars, workshops and technical conferences. Adhesives corporations like 3M, National Starch, Eastman Kodak, Sumitomo, and Henkel are among the world's most potent technical industries. Given all this, it's amazing how little is definitively known about how glue actually works -- the actual science of adhesion. There are quite good industrial rules-of-thumb for creating glues; industrial technicians can now combine all kinds of arcane ingredients to design glues with well-defined specifications: qualities such as shear strength, green strength, tack, electrical conductivity, transparency, and impact resistance. But when it comes to actually describing why glue is sticky, it's a different matter, and a far from simple one. A good glue has low surface tension; it spreads rapidly and thoroughly, so that it will wet the entire surface of the substrate. Good wetting is a key to strong adhesive bonds; bad wetting leads to problems like "starved joints," and crannies full of trapped air, moisture, or other atmospheric contaminants, which can weaken the bond. |
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