Phenolic resins reinforcements

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). 

Indirect Contact. Direct contact was more popular in the past, when none of the common construction metals was resistant to chlorine. Typical materials of construction were thermosets (such as a phenolic resin reinforced with asbestos) for vessels and stoneware or glass for piping. This situation changed with improvements in fiber-reinforced plastic fabrication and the commercial advent of titanium. The indirect-contact approach has now become a standard. The typical chlorine cooler today is a single-pass vertical shell-and-tube exchanger with titanium tubes and tube sheets and a carbon steel shell (or perhaps FRF in smaller units). Construction of tube sheets may be of solid titanium, or they may be clad or explosion-bonded with titanium. The inlet channel to the primary cooler also may be of titanium the other channels usually are of FRR... 

Kim S J and Jang H (2000), Friction and wear of friction materials containing two different phenolic resins reinforced with aramid pulp , Tribol Int, 33, 477-484, and references therein. 

Figure 4.3. Scanning electron microscopy (SEM) images showing fracture surfaces of phenolic resin reinforced with 8 wt% (a) acid modified SCF and (b) coupling agent treated SCF [21]...

Electronic baseboards are used for mounting the chips, transistors and other elements of electronic circuitry. They are generally made of either phenolic resin reinforced with cellulose (paper), or epoxy resin reinforced with glass fibre.Their principal purpose is to give physical support to the circuit elements while insulating them from... 

Along with composite insulations, there are other types of insulating materials and structures that do not fit into any of the main categories. An example of such a thermal barrier is honeycomb insulation, which was developed for use in space exploration. This type of insulation, known by its honeycomb structure, is composed of a phenolic resin-reinforced fiberglass cloth. The manufacturing process and the application of honeycomb insulation in the Saturn S-II rocket system is depicted in Fig. 7.11. The cells in the... 

The highest mechanical strengths are usually obtained when the fibre is used in fine fabric form but for many purposes the fibres may be used in mat form, particularly glass fibre. The chemical properties of the laminates are largely determined by the nature of the polymer but capillary attraction along the fibre-resin interface can occur when some of these interfaces are exposed at a laminate surface. In such circumstances the resistance of both reinforcement and matrix must be considered when assessing the suitability of a laminate for use in chemical plant. Glass fibres are most commonly used for chemical plant, in conjunction with phenolic resins, and the latter with furane, epoxide and, sometimes, polyester resins. 

Phenolic resin with an organic (nylon), inorganic (silica), or refractory (carbon) reinforcement Precharred epoxy impregnated with a noncharring resin... 

Silicone rubber filled with microspheres and reinforced with a plastic honeycomb Polybutadiene-acrylonitrile elastomer modified phenolic resin with a subliming powder... 

Compounding ingredients which bring about reinforcement of rubbers. The most widely used are carbon black, silica and silicates, zinc oxide, treated whitings, high styrene resins and phenolic resins. 

One typical example of carbon/carbon composite plates is that made by Oak Ridge National Laboratory (ORNL) in the United States [12]. The composite preform was fabricafed by a slurry-molding process from fhe mixed slurry befween short carbon fibers (graphite fibers were also added in some sample plates) and fhe phenolic resin. The mass rafio between fiber reinforcement and phenolic matrix is 4 3. The phenolic matrix improves the mechanical properties and dimensional stability of the plate. A subsequent vacuum molding process was utilized to fabricate composite plates and fluid fields with relatively high resolution (Figure 5.3, [11]). 

Ceresa (112) used the mechanical synthesis of natural rubber with phenolic resins to achieve rubber reinforcement by the generation of gel. The reaction was... 

Roofing panels have been made from polyisocyanurate foams, both foam- and felt-reinforced with glass fiber. Phenolic resins are used especially for decorative laminates for paneling. The substrate may be fiberboard or a core of expanded polystyrene beads. In one case the beads are coated with phenolic resin, then expanded in a mold to form a structural foam panel. 

Pultrusion [PHENOLIC RESINS] (Vol 18) [PLASTIC PROCESSING] (Vol 19) [REINFORCED PLASTICS] (Vol 21) [COMPOSITEMATERIALS - SURVEY] (Vol 7) resin properties required for [COMPOSITE MATERIALS - POLYMER-MATRIX - THERMOSETS] (Vol 7)... 

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. 

Some of the common types of plastics that are used are thermoplastics, such as poly(phenylene sulfide) (PPS) (see POLYMERS CONTAINING SULFUR), nylons, liquid crystal polymer (LCP), the polyesters (qv) such as polyesters that are 30% glass-fiber reinforced, and poly(ethylene terephthalate) (PET), and polyetherimide (PEI) and thermosets such as diallyl phthalate and phenolic resins (qv). Because of the wide variety of manufacturing processes and usage requirements, these materials are available in several variations which have a range of physical properties. 

The methods used to increase the water resistance of a glass microsphere foam are basically those applied to glass-reinforced plastics, filled thermoplasts, and elastomers, viz. hydrophobic adhesion compounds are added to binder and microsphere dressing 147). The compounds added are alkyl alkoxysilane derivatives, amino or epoxy alkoxysilanes for epoxy and phenolic resins, vinyl or methacryloxy alkoxysilanes for polyester resins. The dressing agents used are aminoethoxysilanes (y-aminopropyl-... 

FRP materials are made up of the polymer and reinforcing fibers. The polymer is typically a thermoset polymer thermoplastics can be used as well. Some typical thermoset polymers used are epoxy resins, unsaturated polyester resins, epoxy vinyl ester resins, phenolic resins, and high performance aerospace resins such as cyanate esters, polyimides, and bismaleimides. These resins... 

Phenolic, Melamine, and Urea. The phenolics are heavily commercialized thermosetting materials that find their way into many applications. They have an excellent combination of physical strength and high-temperature resistance. They have good electrical properties and dimensional stability. Like epoxies and diallyl phthalate, phenolic resins are often found to contain fillers and reinforcement. 

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