Cellulose lamination

This material has been known for many years, being used originally in the making of electric lamp filaments. In principle vulcanised fibre is produced by the action of zinc chloride on absorbent paper. The zinc chloride causes the cellulosic fibres to swell and be covered with a gelatinous layer. Separate layers of paper may be plied together and the zinc chloride subsequently removed to leave a regenerated cellulose laminate. 

See PEG-20 hydrogenated palm oil glycerides PEG-3 hydrogenated rosinate Synonyms POE (3) hydrogenated rosinate Rosin, hydrogenated, triethylene glycol ester Uses Syn. tacky resin in hot-melt, pressure sensitive, and ethyl cellulose laminating adhesives... 

The reinforcing ply of laminates may be a woven fabric scrim, a nonwoven web of polymer monofilaments, or a mat of fibers. One of the most common reinforcements in use is also one of the oldest, ordinary cellulose fiber paper. 

The most commonly used reinforcement for high pressure decorative and industrial laminates is paper (qv). The strong substrate layers, or filler, are kraft paper. Kraft is a brown paper made from a sulfate pulp process (8). It consists of both short cellulose fibers from hardwoods and long fibers from conifers. The long fibers impart most of the wet strength required for resin saturation processes. 

Composite-Based Laminates. Grade CEM-1 are laminates with continuous-filament glass cloth surfaces and a cellulose core, all with a flame-resistant epoxy resin binder. With good punching practice, sheets up to and including 2.4 mm (0.094 in.) in thickness may be punched at temperatures not less than 23°C (73°F). These laminates meet UL94 V-0 when tested in accordance with UL94. 

Although it would be desirable to recycle laminate scrap, this has been difficult because of its thermoset nature. However, a 1993 patent (18) suggested a means whereby scrap consisting of cellulose, thermoset resins, and partially reacted resins can be ground to a powder which is used as a filler in a thermoplastic resin. The filled thermoplastic resin is then used for mol ding of various articles. 

Wood (qv) is arguably the oldest building material used by humans to constmct their dweUings. It is a natural product obtained from trees, used in both stmctural and decorative appHcations. The chemical composition of wood is largely cellulose (qv) and lignin (qv). Today there are a variety of composite or reconstituted wood products, such as plywood, particle board, wood fiber boards, and laminated stmctural beams, where small pieces of wood or wood fiber are combined with adhesives to make larger sheets or boards (see Laminates). 

This includes wire enamels on a base of polyvinyl formal, polyurethane or epoxy resins as well as moulding powder plastics on phenol-formaldehyde and similar binders, with cellulose fillers, laminated plastics on paper and cotton cloth base, triacetate cellulose films, films and fibres of polyethylene terephthalate. 

The polyester alkyd moulding compositions are also based on a resin similar to those used for laminating. They are prepared by blending the resin with cellulose pulp, mineral filler, lubricants, pigments and peroxide curing agents on... 

Synthetic resins are extensively used, e.g., in surface finishes, in the fabrication and repair of boat and motor vehicle bodies, in the manufacture of laminated boards, for electrical components, in pattern making and in paints and varnishes. Non-rubber adhesives made from fish glues and from cotton derivatives (e.g. cellulose acetate) tend not to be sensitizing but, depending upon composition and the manner of use, many other types may pose significant dermatitic and fume hazards. 

Compression and injection molding are used with amino resins to produce articles such as radio cabinets, buttons, and cover plates. Because melamine resins have lower water absorption and better chemical and heat resistance than urea resins, they are used to produce dinnerware and laminates used to cover furniture. Almost ah molded objects use fillers such as cellulose, asbestos, glass, wood flour, glass fiber and paper. The 1997 U.S. production of amino resins was 2.6 billion pounds. 

A comment on the properties of the base employed in reactions that involve the formation of the Vilsmeier-Haack adduct is in order, because several derivatives of cellulose are obtained by this route. Preparation of Cell-Tos has been attempted in LiCl/DMAc, by reacting the polymer with TosCl/base. Whereas the desired product was obtained by employing triethy-lamine, use of pyridine (Py) resulted in the formation of chlorodeoxycellu-lose. In order to explain these results, the following reaction pathways have been suggested [147] ... 

Packaging materials which have a smooth, impervious surface, free fi cm crevices or interstices, such as cellulose acetate, polyethylene, polypropylene, poly vinylchloride, and metal foils and laminates, all have a low surface microbial count. Cardboard and paperboard, unless treated, carry mould spores of Cladosporium spp., Aspergillus spp. md Penicillium spp. and bacteria such 2 Bacillus spp. sn.dMicrococcus spp. 

Nonwoven materials such as cellulosic fibers have never been successfully used in lithium batteries. This lack of interest is related to the hygroscopic nature of cellulosic papers and films, their tendency to degrade in contact with lithium metal, and their susceptibility to pinhole formation at thickness of less than 100 fjim. For future applications, such as electric vehicles and load leveling systems at electric power plants, cellulosic separators may find a place because of their stability at higher temperatures when compared to polyolefins. They may be laminated with polyolefin separators to provide high-temperature melt integrity. 

This safety glass turned yellow after several years of exposure to light. The bonding layer was replaced in 1933 by cellulose acetate, made from the reaction of cotton with acetic acid. By 1939 this was replaced by poly(vinyl butyral) (PVB), which is still in use today as the adhesive placed between sheets of glass to produce laminated safety glass. This is one of a very few modern-use materials that has retained the same basic materials for over 60 years. 

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