Adhesive rollers

Uses Bitumen modifier hot-melt pressure-sensitive adhesives roller coverings rubber shoe soling compds. sealants food-contact and medical applies. 

Paper adhesives in solid (glue sticks), liquid, or cassette form (adhesive rollers)... 

Adhesive Rollers (Paper Adhesives in Cassette Form). Adhesive rollers are newly developed adhesive systems for gluing paper, cardboard, and photos. The adhesive film is applied to a paper or foil carrier which is rolled up and placed in a cassette, usually with automatic take-up. This adhesive film is then rolled onto the parts to be glued on a solid surface. Adhesive rollers have the advantage over conventional paper adhesives that no drying time needs to be allowed after application of the solvent- and water-free adhesive film. Adhesive rollers are offered in various sizes, sometimes with refill cassettes. They are available for permanent and nonpermanent applications. 

The types of equipment available to assist in the bonding operation, ie jigs, fixtures, adhesive rollers, ovens, other types of heating equipment, presses, etc. 

Contact cleaning Removing particles from a surface using an elastomer or adhesive roller that picks up the particles. In some designs the particles on the elastomer are continuously transferred to an adhesive tape. 

The stabihty of the emulsions further permits them to be compounded in simple Hquid-blending vessels by means of agitators, eg, marine-type propellers, paddles, or turbines. The adhesives can be adapted to any type of machine appHcation, ie, from spray guns to rollers to extmder-type devices. Different appHcators are fairly specific in their viscosity requirements, as are the various substrates receiving the adhesive. 

The rubbers are also used for such diverse applications as blood transfusion tubing capable of sterilisation, antibiotic container closures, electric iron gaskets, domestic refrigerators and non-adhesive rubber-covered rollers for handling such materials as confectionery and adhesive tape. The cold-curing rubbers are of value in potting and encapsulation. 

There are many applications in which it is necessary to put a plastic coating on to paper or metal sheets and the extruder provides an ideal way of doing this. Normally a thin film of plastic is extruded from a slit die and is immediately brought into contact with the medium to be coated. The composite is then passed between rollers to ensure proper adhesion at the interface and to control the thickness of the coating (see Fig. 4.26). 

These additives reduce the friction between the polymer aggregates or crystallites and also lower the adhesion between the polymer melt and metal surfaces (which occurs in rollers, extruders). This results in ... 

These materials prevent adhesion between chilled rollers in film production or moulds for injection moulding. They behave like external lubricants, and should serve the following requirements ... 

The technique of film formation from aqueous polymer dispersions is widely used in the field of paints ( dispersion paints , latex-paints ), coatings, and adhesives. The equipment is simple brush, scraper, rake, or roller. 

Hot melt adhesive compositions are used among others to bond edgebands. During edgebanding, the hot melt adhesive is maintained in the molten state in the glue pot of the edgebanding apparatus for extended periods of time. Fillers are added to hot melt adhesive compositions in order to decrease the costs of the adhesive composition and to improve the break action, such that it provides a clean break from the roller during the application procedure (25). 

Poly(vinyl acetate) dry resins and ethylene-vinyl acetate (EVA) copolymers are used in solvent adhesives, which can be applied by total industrial techniques, e.g., brushing, knife-coating, roller-coating, spraying, or dipping... 

Most cells do not readily grow in suspension, and so this method has limited applicability. However, erythropoietic cells (lymphocytes, hybridomas, and erythroleukaemia cells) show no tendency to adhere to glass or plastic surfaces and will survive if allowed to sit on the bottom of a tube, dish or bottle covered with a shallow layer of medium. Other cells that are grown in suspension have been selected on the basis that they show poor adhesion to the substratum and they continue to grow if maintained in suspension. If not continuously agitated they will, however, settle down and adhere to the substratum. With some cells it is sufficient to maintain them in roller bottles rotating at about 2 r.p.m. but in general special suspension... 

For successful use of such adhesives, not only must the formulation be suitable but the system for application also must be efficient. The molten adhesive must be maintained in a fluid condition and at the correct temperature for application over-heating could cause degradation, and if it is too cold the viscosity of an adhesive might be too high. The hot fluid is pumped to the substrate through a suitable nozzle but if the distance between the reservoir and the nozzle is appreciable there may be cooling and a need for heated hoses. Sometimes, molten adhesive is transferred to a coater of the heated-roller type, where again the control of temperature is important. There is a wide variety of equipment for application and every manufacturer of hot-melt adhesives will advise on systems that are suitable for use with them. 

Composite boards are made by bonding decorative laminate of thickness normally 0.4 to 1.5 mm to one or both faces of a substrate, using a suitable adhesive. The most common method of manufacture is flat pressing, which (depending upon the type of adhesive) may be carried out hot or cold. If the adhesive is of the spray-coated contact type, mechanical nip rollers may be employed instead of flat pressing. 

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