Foil adhesion

Film and foil adhesives based on internally plastici2ed copolymer adhesives have been suggested. For instance, vinyl acetate—ethylene or vinyl acetate—acrylate copolymers may be used for adhesion of films to porous surfaces. For metallic foil adhesion, copolymers containing carboxylate functionahty are suggested. 

The structure—N/C-coated cellophane/polyethylene/aluminum foil/ adhesive/50ga polyester/adhesive/polyethylene—had a shelf life of over 6-9 months with no moisture, flavor, or color loss. This barrier system contained the product successfully (see Table IV). 

Cover with aluminum foil adhesive tape (Costar, cat. no. 6570) and seal wells with the edge of a 3M plastic PCR plate sealer device. 

Add 30 pL of HiDi formamide, cover with aluminum foil adhesive tape spin for 1 s at 6200g triturate five times or allow pellets to resuspend for at least 4 h at 4°C transfer contents to 96-well plates and store at -20 C. 

Fig. 3.38. Delamination force of the polymer coating - A1 foil adhesive joints versus oil-soluble Cl content in HDPE (1) SIM (2) Ukramin...

Furniture Foil Adhesives. These adhesives consist primarily of ethylene-vinyl acetate copol)mer emulsions. Rigid PVC and melamine-paper foils, generally 0.2 - 0.4 mm thick, are applied to wood-based materials for decorative purposes. The adhesives must exhibit high tack and high resistance to heat and cold and must counteract the shrinkage of the film (application weight 60-100g/m ). 

Aluminum foil adhesives Methyl vinyl United States 2,785,993 1957 Celanese... 

Laminate structures are PET/adhesive/aluminium foil/adhesive/PE. Adhesive interaction with the ink system or the ability to reach sufficient adhesion to aluminium foil is the... 

High-performance applications laminates for retort pouches Typical laminate structures are PET/ink/adhesive/aluminium foil/adhesive/PP. The retort process, i3o°C for 30 min without delamination of layers, is the challenge for this application. 

Extrusion lamination, or sandwich lamination, is a process related to extrusion coating. In this case, the extrusion coated layer is treated with ozone and used as an adhesive layer (or tie layer) between two or more substrates. A second layer is applied to the extrusion coating while it is still hot and then the sandwich is pressed together by pressure rolls. In film lamination, a fabricated film is adhered to a moving substrate by application of heat and pressure. Film lamination includes several methods with different combination of heat and pressure to ensure foil adhesion. 

Most of the polymer s characteristics stem from its molecular stmcture, which like POE, promotes solubiUty in a variety of solvents in addition to water. It exhibits Newtonian rheology and is mechanically stable relative to other thermoplastics. It also forms miscible blends with a variety of other polymers. The water solubiUty and hot meltable characteristics promote adhesion in a number of appHcations. PEOX has been observed to promote adhesion comparable with PVP and PVA on aluminum foil, cellophane, nylon, poly(methyl methacrylate), and poly(ethylene terephthalate), and in composite systems improved tensile strength and Izod impact properties have been noted. 

Ziac foil coated with a conductive, pressure-sensitive adhesive is used for repair of other ziac coatings or for imparting corrosion resistance at field sites. The 0.08-mm ziac tape or sheet has a 0.025-mm coaductive adhesive. The laminate is cut to size and pressed tightly to activate the adhesive. Conductive tape can be wrapped around pipe, especially around welds or connections. The corrosion resistance of this material is iatermediate between galvanized or thermally sprayed coatings and zinc-filled paints (21,50). 

Fiber dmms can be produced to meet a wide variety of requirements. They can be constmcted with adhesives for water resistance, their interiors can be coated, their walls and ends can incorporate metal foil or asphalt-impregnated pHes, and their exteriors can be decorated by painting, varnishing, and silk screening for both ornamental and functional purposes. 

In contrast to most extmsion processes, extmsion coating involves a hot melt, ca 340°C. The thin web cools rapidly between the die and nip even at high linear rates. Both mechanical and chemical bonding to substrates are involved. Mechanical locking of resin around fibers contributes to the resin s adhesion to paper. Some oxidation of the melt takes place in the air gap, thereby providing sites for chemical bonding to aluminum foil. Excessive oxidation causes poor heat-sealing characteristics. 

Titanium alkoxides are used for the hardening and cross-linking of epoxy, siUcon, urea, melamine, and terephthalate resins in the manufacture of noncorrodable, high temperature lacquers in the sol-gel process as water repellents and adhesive agents (especially with foils) to improve glass surfaces as catalyst in olefin polymeri2ation, and for condensation and esterification. 

Adhesive Transfer Processes. Many polymers, whether dehberately or accidentally, are adhesives, so that much of the adhesive industry can be regarded as a part of the mbber and plastics industry. However, there are several important material-transfer appHcations involving polymer products that are so critically dependent on controlled adhesion that they merit specific mention in that category. They include hot stamping foils, release coatings for pressure-sensitive adhesive products, photocopier materials, transfer coatings, and transfer printing of textiles. 

The chelated organic titanates also function as adhesion promoters of the ink binder to printed substrates such as plastic films, paper, and aluminum foil (504). The acetylacetone complexes of titanium are the preferred products for promoting adhesion of printing inks to polypropylene films. 

Adhesives. Poly(vinyl alcohol) is used as a component in a wide variety of general-purpose adhesives to bond ceUulosic materials, such as paper and paperboard, wood textiles, some metal foils, and porous ceramic surfaces, to each other. It is also an effective binder for pigments and other finely divided powders. Both fully and partially hydrolyzed grades are used. Sensitivity to water increases with decreasing degree of hydrolysis and the addition of plasticizer. Poly(vinyl alcohol) in many appHcations is employed as an additive to other polymer systems to improve the cohesive strength, film flexibiUty, moisture resistance, and other properties. It is incorporated into a wide variety of adhesives through its use as a protective coUoid in emulsion p olymerization. 

The Nitro-dur system, marketed by Key Pharmaceuticals, Inc., contains nitroglycerin in acryUc-based polymeric adhesives with a cross-linking agent for polymer stabiUty. This depot of dmg provides a continuous source of active ingredient. An impermeable backing prevents release of nitroglycerin away from the skin. The systems are individually sealed in a paper polyethylene-foil pouch (81). 

ProStep, developed by Elan and marketed by Ledede, dehvers nicotine over 24 hours (107) and is available ia a 22 mg dose (108). The system consists of a nicotine-containing carrageenan gel embedded and heat-sealed iato a foil—polyethylene laminate to isolate the nicotine from a peripheral acryhc adhesive duriag storage. 

Latex Adhesive Applications. Polychloroprene latex adhesives have a long history of use in foil laminating adhesives, facing adhesives, and constmction mastics. Increasingly stringent restrictions on the emission of photoreactive solvents has heightened interest in latex compounds for broader apphcations, particularly contact bond adhesives. Table 10 makes a general comparison of solvent and latex contact bond adhesives (158). 

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