Reinforced-plastic fiber direction

Aspect ratio It is the ratio of length (L) to diameter (D) of a material such as a fiber or rod also the ratio of the major to minor axis lengths of a material such as a particle. These ratios can be used in determining the effect of dispersed additive fibers and/or particles on the viscosity of a fluid/melt and in turn on the performance of the compound based on L/D ratios. In reinforced plastics, fiber L/D will have a direct influence on the reinforced plastic performance. 

Laminates ate a special form of composite material or reinforced plastic because the continuous reinforcing ply of fibrous material imparts significant strength in the x—j plane. The strength along the axis results from interlaminar bonding of resins. Very few fibers ate oriented in the direction, so it tends to be the weak link in this type of composite. 

Molecular orientation results in increased stiffness, strength, and toughness (Table 8-12) as well as resistance to liquid and gas permeation, crazing, microcracks, and others in the direction or plane of the orientation. The orientation of fibers in reinforced plastics causes similar positive influences. Orientation in effect provides a means of tailoring and improving the properties of plastics. 

The diaminobenzenes are made from benzene by a combination chlorination-nitration route although para-phenylene diamine is also made directly from aniline. orr/to-Phenylene diamine is widely used for the preparation of biologically active compounds such as fungicides and veterinarian medicines. The mera-diamine is used in fire-retardant textile fibers ( Nomex ) while the / ara-diamine finds use in high-strength textile fibers used for bullet-proof vests, sails, army helmets, and other types of fiber-reinforced plastics ( Kevlar ). 

For typical filament winding applications, the fiber reinforcement provides the stiffness and strength required to maintain structural integrity. Thus, material characterization for filament wound structures focuses on characterizing the fiber dominated stiffness and strength properties of the composite. The stiffness of fiber reinforced plastics (FRPs), in the fiber direction, is dominated by the fiber stiffness characteristics. The strength will be influenced by a number of factors, however, and not all of them are related to the fiber, including ... 

An important type of orienting fabricated products concerns applying directional properties to plastics by using fiber reinforcements. Orientation is the alignment of fiber reinforcement within the product that affects mechanical properties. The reinforced plastic (RP) properties increase in the direction of alignment (Figure 3.4). 

In the European Union, the design, manufacture, and use of pressure systems is covered by the Pressure Equipment Directive (Council Directive 97/23/EC) whose use became mandatory in May 2002. European standard EN 13445 provides similar rules and guidelines to the ASME BPV Code. The design of fiber-reinforced plastic vessels is covered by European standard EN 13923. 

A special case of fiber reinforcement is the addition of oriented fibers. Reinforcement glass fibers and plastic bars placed along the principal stress directions reduce the creep deformation, which if present to a large degree, might result in an impaired structure or even cause structural collapse. 

While the previously described three membrane modules required flat sheet membrane material for their preparation, special membrane configurations are needed for the preparation of the tubular, capillary, and hollow fiber modules. The tubular membrane module consists of membrane tubes placed into porous stainless steel or fiber glass reinforced plastic pipes. The pressurized feed solution flows down the tube bore and the permeate is collected on the outer side of the porous support pipe, as indicated in Figure 1.33 (d). The diameters of tubular membranes are typically between 1-2.5 cm. In some modules, the membranes are cast directly on the porous pipes and in others they are prepared separately as tubes and then installed into the support pipes. 

During the 1940s the Society of the Plastics Industry started the Low Pressure Industries Division, which shortly thereafter became the Reinforced Plastics Division under the direction of Charlie Condit and in 1954, with D. V. Rosato s leadership, the Reinforced Plastics/Com-posite Division. It is currently called the Composites Institute. The original product was glass-fiber-thermoset polyester plastic RPs. To date about 90wt% of all RPs continue to be glass-fiber-TS polyester plastics. 

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