Pultrudate

Thermoformed chassis and body panels are featured on the car. The products were made initially in the USA for assembly in China. The car will weigh less than 2000 lb (900 kg). Automotive Design Composites, Inc of San Antonio, TX, designed the vehicle to have body panels and trunk formed from coextruded sheet of ABS with an ASA cap layer that will hang on a pultruded composite frame. Ceramic tooling is used to thermoform plastic products. 

The chassis is made from a 1/4 in. sheet of either ABS or TPO vacuum formed into a tub and reinforced with reinforced pultruded glass fiber-TS polyester plastic tubing. The hood and other products are being made from a 20 mm thick sandwich of thermo-formed PPO-alloy skins, glass fabric infused with thermosetting vinyl ester, and a urethane foam core. The bumper and front fascia is thermoformed from a polyolefin elastomer sheet with an UV-resistant cap layer of DuPont s Tediar PVF film. The dash and... 

The primary UPR end markets are construction, automotive, and marine industries widi applications such as house paneling, tub and shower applications, chemical-resistant storage tanks, pultruded profiles, and fiberglass composite boat hulls. The UPR industry is mature, with a world production close to 1.7 million tons (Table 2.2), but must face two important issues increasingly strict regulations for styrene emissions and poor recycling potential for polyester thermosets.48 49... 

Framework pultruded long glass fibre reinforced plastics. 

Boukhili, B., Hubert, P. and Gauvin, R. (1991). Loading rate effect as a function of the span-to-depth ratio in three-point bend testing of unidirectional pultruded composites. Composites 22, 39-45. 

The preceding short process description is based on the most basic—but also most common—pultrusion setup. There are several variations to the theme, however, and many details were intentionally left out. In the following, the process is described in some detail and different processing and machinery options are briefly discussed. The variety in machinery solutions reflect the fact that many, perhaps most, pultrusion machines used to be designed and built inhouse by the pultruder rather than by a dedicated machinery manufacturer. There... 

To increase throughput when pultruding reasonably simple components, it is common practice to mount several dies in parallel in the same pultrusion machine. This procedure is referred to as multistream or multicavity pultrusion. 

The applications of pultruded products range from sporting goods to electrical and construction. Figure 11.3 illustrates the application distribution in the United States, Japan, and Europe [2], Some applications in the respective categories of Figure 11.3 include ... 

Figure 11.3 Applications of pultruded composites in the United States, Japan, and Europe in 1991 [2]...

The most spectacular application example to date is perhaps the Aberfeldy footbridge over the river Tay in Scotland (see Fig. 11.4). This bridge is 113-m long, has a deck width of 2.2 m, and a main span of 113 m [4]. The entire deck structure, hand rails, and A-frame towers are pultruded composites, and the cable stays are Kevlar ropes. The deck structure is assembled from a modular system of pultruded 6-m long, hollow components, which consist of 70 percent by weight of E glass and 30 percent pigmented isophtalic polyester resin. 

Despite the excellent stiffness- and strength-to-weight ratios obtainable in pultruded composites, it is interesting to note that more than half of all pultruded composites were probably sold for nonstructural applications (cf. Fig. 11.3). 

As pointed out in the beginning of the chapter—and perhaps also noticeable from the process description earlier—the pultrusion process at first appears rather simple and straightforward however, several intricacies arise on closer inspection. The key technology issues of pultrusion of thermoset-matrix composites are usually considered to be resin formulation, temperature control, material guidance, and die design (not in order of importance). It is typically the skill in these areas that distinguishes a successful pultruder from his hapless competitor. 

Characteristic Cast resin Filled resin Glass-reinforced laminate Filament-wound laminate Pultruded profile... 

Note that Da1 is our dimensionless mean residence time and Da" = n3. Da111 represents the ratio of the heat of reaction to the heat removed via convection. The ratio DaIV /Da111 = Ped/L = Gr represents the convection in the machine direction to the conduction through the thickness of the pultruded product. 

You are to pultrude a thin fiber reinforced epoxy plate at arate of lcm/s. Assume kinetic properties given in the last two problems and that the material is best represented with the autocatalytic second order reaction kinetic model of the previous problem. You are asked to design the die and the process to manufacture this product. 

These resins act more as polyester resins than they do as epoxy resins. They are easily processed, have fast cure rates at room temperature, and can be cured with peroxides. They effectively wet out glass fiber reinforcement and cure quickly. Therefore, vinyl ester resins are often used in the manufacture of composites such as filament- wound and pultruded structures. 

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