Paper adhesion

Emulsion Polymerization. Emulsion polymerization is the most important industrial method for the preparation of acryhc polymers. The principal markets for aqueous dispersion polymers made by emulsion polymerization of acryhc esters are the paint, paper, adhesives, textile, floor pohsh, and leather industries, where they are used principally as coatings or binders. Copolymers of either ethyl acrylate or butyl acrylate with methyl methacrylate are most common. 

The largest market for elastomer-based adhesives is that of lamination (see Laminates). Modem office furniture having Formica as a surfacing material is made with an elastomer-based adhesive. Tile adhesives for ceramic or carpet tile are also elastomer-based and usually solvent appHed. Paper adhesives and shoe manufacture also use substantial quantities of mbber-based materials. Solvent-weld adhesives are used to join plastic plumbing and to repair vinyl sheeting. 

In the late 1800s, when the demand for coated paper for the halftone printing process increased, casein rapidly replaced glue. Casein forms a hard, tough film when dry, and can be waterproofed easily with formaldehyde (qv). The properties of soy protein are similar to those of casein, and soy protein has been substituted for it in many types of coated papers requiring a casein-type binder (see Soybeans and other oilseeds). Casein, a valuable food product, is seldom used as a paper adhesive, in spite of its excellent adhesive properties. 

Styrene—Butadiene Latex. SB latex is used in coatings, carpet backing, paper adhesives, cement additives, and latex paint. 

Poly(vinyl acetate) emulsions are excellent bases for water-resistant paper adhesives destined for use in manufacturing bags, tubes, and cartons. Glue-lap adhesives, which require moderate-to-high resistance to water, exemplify this type. When routine water resistance is required, a homopolymer vinyl acetate emulsion containing a ceUulosic protective coUoid is effective for most purposes. Next effective are emulsions containing fuUy hydrolyzed poly(vinyl alcohol) as a protective coUoid, foUowed by those containing partiaUy hydrolyzed poly(vinyl acetate). 

As a result of extensive development and testing by thermoprocessing or aseptic techniques, the use of flexible, laminated aluminum pouches and formed aluminum containers for shelf-stable foods is nearing commercial reality. The increasing use of aluminum for food packaging has been made possible by successfully combining it with specialized plastics, papers, adhesives, and coatings. In many applications, aesthetic as well as protective characteristics are also provided. 

Amylopectin is the polymeric component of starch and consists mainly of glucose units joined at the 1,4-positions. Relative molar mass tends to be very high, e.g. between 7 and 70 million. A variety of modified starches are used commercially which are produced by derivatisation to give materials such as ethanoates (acetates), phosphates, and hydroxyalkyl ethers. Modified and unmodified starches are used in approximately equal tonnages, mainly in papermaking, paper coatings, paper adhesives, textile sizes, and food thickeners. 

Gel. A jelly-like substance formed as solutes (materials in solution) from submicroscopic crystalline particle groups that capture much or all of the solvent in their interstices or structure. Usually, the solutes are a small proportion, maybe 1-2% of the gel. Gels can be used for filters and clarifying agents, textile and paper adhesives, polymerization precursors, and of course, as a component in gelatin the Italian ice cream. 

In various kinds of industrial production, materials need to be treated with charged colloidal particles. In such systems, the value of the zeta-potential analyses are needed to control production. For example, in paper, adhesive, and synthetic plastics, colloidal clay can be used as filler. In oil drilling, clay colloidal suspensions are used. The zeta potential is controlled so as to avoid clogging the pumping process in the oil well. It has been found that, for instance, the viscosity of a clay suspension shows a minimum when the zeta potential is changed (with the help of pH from 1 to 7) from 15 to 35 mV. Similar observations have been reported in coal slurry viscosity. The viscosity was controlled by the zeta potential. 

Both of the heat-activated types are more costly than conventional paper-adhesive labeling. Selected advantages may offset the cost increase for example... 

PCBs Polychlorinated biphenyls are a group of toxic chemicals used for a variety of purposes and found in a number of products, such as carbonless copy paper, adhesives, hydraulic fluids, and caulking compounds. They were originally used to insulate electrical equipment, and although they ve been banned in the United States since the late seventies, they are still found in water. They accumulate in the sediment at the bottoms of rivers and lakes, and build up in the fatty tissues offish. The primary effect of PCBs is on the endocrine system, which is responsible for regulating the hormones in our bodies. They are particularly dangerous to fetuses and young children. If PCBs get into your bloodstream, they can upset the body s natural hormone levels and can lead to birth defects and cancers. 

It was noted that PCBs might also be present in minute quantities in some consumer products such as small old electrical appliances/parts, electronics, impact papers, adhesives, sealants, plastic materials and paints. The 2003 Hong Kong Census and Statistic figures showed local trading activities of these consumer products. However, in the absence of information on the product content of PCBs, no estimate of total PCBs in semi-closed and open application could be made. The relative contribution from this category to total PCB use was likely to be insignificant. 

Uses Preparation of emulsions, sizing paper, adhesives, light filters. 

This involves heating the glassware to 160°C for 90-120 min. It is the preferred method for bottles which do not have screw caps when their orifice should be covered with aluminium foil. It is also used for glass Petri dishes and pipettes. Petri dishes should either be stacked in tins or containers specially designed for them or simply held closed with sterilisation tape. This brown paper adhesive tape has pale strips which turn dark brown under sterilising conditions and is used as an indicator of the effectiveness of the procedure. It is available from the 3 M Company Ltd. (Appendix 3). 

Can book paper, adhesives, covering materials, etc. be designed to be highly resistant to water damage so that books printed in the future will be more receptive to mass recovery techniques ... 

Rupture of the paper-adhesive system. Where the paper ruptured first, result is... 

Main commercial uses Food, paper adhesives Sugar, paper, corrugated board Food, adhesives Sugar, bakery Food, adhesives... 

N-trichloromethylthio-4-cyclohexene-2,2-dicarboximide. Technical grade of captan used as an industrial preservative, a wall paper adhesive preservative and in veterinary products for skin diseases. 

Reaction of starch with polyphosphates or phosphorus containing reagents, which is utilized in paper, adhesives, and textiles. 

---