Phenolic-reinforced paper

Overlays for plywood deserves mentioning. Overlays for plywood may be anything that conceivably can stick to the panel and have end use utility. Overlays include polyester or phenolic impregnated paper (either medium or high density types), fiberglass-reinforced plastic, fabric, high pressure laminates, aluminum, lead, polyurethane insulation and pebbles. The uses for plywood are extensive and marriage with other overlay materials expand these uses tremendously. 

Fig. 8-3. New honeycomb material enters truck trailer, marine container and modular housing field. Polyester-glass reinforced sandwich cuts fabrication costs, maintenance, and reduces weight by more than 20%. A new paper honeycomb sandwich material beefed up by fiber glass reinforced polyester resin is now making inroads into three markets presently dominated by aluminum, steel, wood and other materials. Pictured above is a view of the new material which essentially consists of fiber glass reinforced polyester skins around a phenolic-impregnated paper honeycomb interior. (Courtesy A. J. Lazarus Associates Inc.)...

MIL-P-3115B Thermoset Phenolic Sheet, Paper Reinforced... 

Thermoset Phenolic Sheet, Paper Reinforced Adhesive Coated, Paper-Backed, Plastic Sheet Thermosetting Resins Cast from Monomers Sheet and Rods Scribe-Coated Plastic Sheet Tracing, Glazed and Matte Finish Plastic Sheet FEP Fluorocarbon Extruded Sheet and Film Polyethylene, Laminated, Nylon Reinforced Sheet Styrene-Butadiene Sheet... 

There are now commercially available a large range of laminated plastics materials. Resins used include the phenolics, the aminoplastics, polyesters, epoxies, silicones and the furane resins, whilst reinforcements may be of paper, cotton fibre, other organic fibres, asbestos, carbon fibre or glass fibre. Of these the phenolics were the first to achieve commercial significance and they are still of considerable importance. 

Seventy years ago, nearly all resources for the production of commodities and many technical products were materials derived from natural textiles. Textiles, ropes, canvas, and paper were made of local natural fibers, such as flax and hemp. Some of them are still used today. In 1908, the first composite materials were applied for the fabrication of big quantities of sheets, tubes, and pipes in electrotechnical usage (paper or cotton as reinforcement in sheets made of phenol- or melamine-formaldehyde resins). In 1896, for example, airplane seats and fuel tanks were made of natural fibers with a small content of polymeric binders [1]. 

The first synthetic plastics were the phenol-formaldehyde resins introduced by Baekeland in 1907 [1], Melamine and urea also react with formaldehyde to form intermediate methylol compounds which condense to cross-linked polymers much like phenol-formaldehyde resins. Paper, cotton fabric, wood flour or other forms of cellulose have long been used to reinforce these methylol-functional polymers. Methylol groups react with hydroxyl groups of cellulose to form stable ether linkages to bond filler to polymers. Cellulose is so compatible with these resins that no one thought of an interface between them, and the term reinforced composites was not even used to describe these reinforced systems. 

The quantity of resin applied to the reinforcing ply to achieve a state of full densification varies inversely with the laminating pressure. Therefore, high pressure laminates pressed at about 7 MPa (1000 psi) need only about 25—30% phenolic resin in kraft paper, whereas low pressure (1 MPa = 145 psi) laminates need 50—60% resin in the reinforcing ply if all voids are to be filled in the final product. 

A new approach was proposed for making effective helmets which could replace the former British army steel helmet. Essentially the new helmet used modified phenolic resins reinforced with nylon, and the crown cap inside was thermoformed from polyethylene. Formerly the crown cap was attached to the steel by rivets—not an appropriate method for fixing polyethylene to reinforced plastics. Instead a method was developed with a hot-melt adhesive based on ethylene-vinyl acetate copolymers cast as film on release paper. For assembly, the cast film is cut in advance to match the intricate shape required and activated by heat to bond under light pressure subsequently, a further heat activation is employed to fix the crown cap in place (Figure 52 illustrates this). 

In the virtually ignored study by Dai (with three nonself citations in five years) [521], the paper by Graham [451] is not cited either, but the key issue is both identified and clarified. Based on the results summarized in Fig. 21, the author concluded that electrostatic interaction between cationic dyes and the surface of activated carbon has a great effect on adsorption capacity. Below the isoelectric point of the activated carbon (when the positive zeta potential was above 60 mV), the capacity is significantly reduced due to electrostatic repulsion between cationic dyes and the carbon surface. In a follow-up study, while still failing to acknowledge earlier important contributions to the resolution of the key issues, Dai [522] reinforced and confirmed the electrostatic attraction vs. repulsion arguments. The author used anionic dyes (phenol red, carmine, and titan yellow) and... 

Materials for rigid laminates include paper-phenolic (the original material), paper-epoxy, and glass-epoxy. Composite laminates, which contain two or more types of reinforcing... 

The combination of an adhesive and adherend is a laminate. Commercial laminates are produced on a large scale with wood as the adherend and phenolic, urea, epoxy, resorcinol, or polyester resins as the adhesives. Many wood laminates are called plywood. Laminates of paper or textile include items under the trade names of Formica and Micarta. Laminates of phenolic, nylon, or silicone resins with cotton, asbestos, paper, or glass textile are used as mechanical, electrical, and general purpose structural materials. Composites of fibrous glass, mat or sheet, and epoxy or polyester resins are widely employed as reinforced plastic (FRP) structures. 

In the manufacture of laminates for electrical insulation, paper (which is the best dielectric) is normally used as the base reinforcement. Phenolic paper laminates are extensively used for high-voltage insulation applications. 

Kraft paper is widely used as a reinforcement. When saturated with phenolics, it is made into a common printed wiring board. When combined with melamine, it becomes a decorative high-pressure laminate used in furniture, countertops, and wall panels. Paper reinforcement is inexpensive and easy to machine, drill, and pxmch. It imparts good electrical properties, but it is sensitive to moisture and cannot withstand high temperatures. 

Chem. Descrip. Calcium carbonate CAS 471-34-1 EINECS/ELINCS 207-439-9 Uses Filler tor paints, paper, paper coating, PVC, rubber (automotive goods, footwear, medical supplies), thermoplastics (PP, nylon, urethanes, HOPE, LDPE, ABS, PS), thermosets (SMC, BMC, TMC glass reinforced polyesters, epoxy, alkaline phenolics), caulks, glazing compds., ceramics, adhesives, food processing... 

These are used in bonding metal or reinforced plastic facings to paper (resin impregnated) honeycomb structures, cork and rubber compositions, cyclized and unvulcanized rubbers, steel to vulcanized rubber, and electrical applications. They are also used as primer for metals to be bonded to wood with phenolics. Polyvinyl butyral-phenolics lack the shear strength and toughness of the polyvinyl formal-phenolic type. ... 

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