Laminate Contact pressure

Another widely used overlay adhesive is the contact type. These specialized adhesives, in the same group as mbber cement, may be of the solvent-base or water-base types. They are often used to bond overlays such as wood veneer, vinyl (poly(vinyl chloride)) films, or high pressure laminates such as countertop overlays. 

Molding, contact pressure Method of molding or laminating whereby... 

This refers to many different fabricated RP products such as high or contact/low pressure laminates. It usually identifies flat or curved panels using high pressure rather than contact or low pressure. It is a product made by bonding together two or more layers of laminate materials. The usual resins are thermoset such as epoxies, phenolics, melamines, and TS polyesters. A modification of this process uses TPs. The type of materials can be endless depending on market requirements. Included are one or more combinations of different woven and/or nonwoven fabrics, aluminum, steel, paper, plastic film, etc. 

Polycondensation adhesives based on phenol or phenol derivates with formaldehyde are mainly used in the production of wooden constructions (in woodworking one traditionally talks of glueing instead of bonding ), for example, in the manufacturing of laminated bonds (plywood, chipboard, fiber board, beams). Since in these applications, the adherends are able to absorb the water developing during the polycondensation reaction, the processing occurs in heated presses to enable the application of the necessary contact pressure at the required temperature (Section 7.2.4). For applications in nonindustrial fields these adhesive are practically unimportant. 

Polychloroprene latices are mainly used for high-pressure lamination, for foam bonding and for vinyl substrates (such as PVC) adhesion. Also, they are used for foil lamination, carpet installation, and PVC floor tile bonding. Bonding and shaping of foams is done with highly crystalhzable water-borne polychloroprene adhesives. The adhesive is sprayed on the foam and immediately the foam pieces are placed in contact. The assembly is wet-bonded because no drying is necessary as the water will dissipate into the foam. 

The adhesion of colored coatings on glass fibers is improved by first treating the fiber with colloidal silica and heating to just below the fusion temperature (600). Colloidal silica is also added to adhesives (601). Colloidal silica plus a contact-pressure type of binding resin may be used for laminating cellulosic fabrics (602). 

For free-standing electrodes, integration with collectors becomes even more important to avoid resistances because there is no intimate surface contact. This highlights the importance of high pressure lamination to reduce contact resistance between collector and active material when an inti-... 

Contact Resin n A liquid resin that thickens or crosslinks on heating and, when used for bonding laminates, requires little or no pressure. Typical components are an unsaturated monomer such as an aUyl ester, or a mixture of styrene or other vinyl monomer with an unsaturated polyester or alkyd. See Contact-Pressure Resin. 

Interesting developments were also taking place in the field of thermosetting resins. The melamine-formaldehyde materials appeared commercially in 1940 whilst soon afterwards in the United States the first contact resins were used. With these materials, the forerunners of today s polyester laminating resins, it was found possible to produce laminates without the need for application of external pressure. The first experiments in epoxide resins were also taking place during this period. 

Contact molding Process whereby layers of resin-impregnated fabrics are built up one layer at a time onto the mold surface forming the product. Little or no pressure is required for laminate curing. 

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