Winding process

As shown in Fig. 7.2 the main steps of the filament winding process chain are the material supply, tension build-up, heating and consolidation. Depending on the individual winding equipment configuration and winding head technology several different setups are possible. 

The first step in a filament winding process chain is the material rack. The fiber material, whether already impregnated, that is tape material, or not, that is, roving material, delivered on spools is mounted here. The number of spools depends on the winding head technology used and the components dimension. In addition to the material storage, a spool creel can also be 

At the online-impregnation process (see section Direct impregnation technology ) the polymer is heated and melted with an extruder (external) and transported to an impregnation tool near the mandrel or directly on the mandrel. To reach a good bonding between the incoming molten material 

4 Heating methods and their thermal expansion in the tape. 

For an optimal consolidation it is necessary to apply a consolidation pressure in the winding process. After the polymer is molten the rovings/tapes are wound (with consolidation pressure) on the mandrel. Generally, there are two different ways to apply the required consolidation pressure. In the first system the consolidation force is applied only with the tape tension as a result of the break system used (Fig. 7.6). The acting consolidation pressure depends on several factors, besides the acting tension, for example material temperature and viscosity, and the consolidation zone is not well defined. Furthermore, the applied tape tension can induce significant residual stresses in the component. The consohdation roller of the second system apphes 

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Other considerations are important during the physical winding process and involve winding losses, leakage inductance, shielding, and physical space. They do not need to be considered now. 

For dc input voltages that are more than 100 VDC, a layer of Mylar tape should be placed between primary and the secondary(ies) and between any multiple secondaries. One should not completely trust the insulation breakdown voltage rating of the magnet wire since it could nick during the winding process. 

Filament winding Process in which continuous strands of roving or... 

In order to understand the effect of each process variable, a fundamental understanding of the heat transfer and polymer curing kinetics is needed. A systematic experimental approach to optimize the process would be expensive and time consuming. This motivated the authors to use a mathematical model of the filament winding process to optimize processing conditions. 

This paper will discuss the formulation of the simulator for the filament winding process which describes the temperature and extent of cure in a cross-section of a composite part. The model consists of two parts the kinetic model to predict the curing kinetics of the polymeric system and the heat transfer model which incorporates the kinetic model. A Galerkin finite element code was written to solve the specially and time dependent system. The program was implemented on a microcomputer to minimize computer costs. 

Filament winding Process in which continuous strands of roving or roving tape are wound, at a specified pitch and tension, onto the outside surface of a mandrel. Roving is saturated with liquid resin... 

Figure 7.91 Schematic diagram of the filament winding process. Reprinted, by permission, from P. K. Mallick, Fiber-Reinforced Composites, p. 352. Copyright 1988 by Marcel Dekker, Inc.

Cylinders may be wound with a wet winding process while maintaining high fiber volume fractions typically seen in parts made from preimpregnated (B staged) materials. 

There are a number of general references available that contain detailed descriptions of the winding process and equipment itself [5,6], The purpose of this work, however, is to focus on the relationship between processing conditions and final part quality for both thermosetting and thermoplastic matrix filament wound cylinders. In the subsequent sections, an overview of the process will be presented, followed by detailed descriptions of current process modeling techniques and methods for determining cylinder quality. 

Process models allow composite case manufacturers to determine the affects of process variable settings on final cylinder quality. Because the cost of a composite cylinder can be as great as 500,000, the ability to simulate filament winding can significantly reduce cost and improve quality. Several computer models of the filament-winding process for both thermoset and thermoplastic matrix materials have been developed. These models are based on engineering principles such as conservation of mass and energy. As such, numerous resin systems and fiber materials can be modeled. 

Although all functions can be differentiated from first principles, using equation (4.4), this can be a rather long-winded process in practice. In this chapter, we deal with the differentiation of more complicated functions with the aid of a set of rules, all of which may be derived from the defining relation (4.4). In many cases, however, we simply need to learn what the derivative of a particular function is, or how to go about differentiating a certain class of function. For example, we learn that the derivative of y —f x) — sin x is cos x, but that the derivative of y = j(x) = cos x is —sin x. Similarly, we can differentiate any function of the type y =/fx) = x" by remembering the rule that we reduce the index of x by 1, and multiply the result by n that is ... 

Fewer defects in the reel-winding process (creases)... 

Vertical transport and gravitational circulation in estuaries are influenced by both stratification and turbulent mixing, which result from the destabilizing forces of tides and/or wind processes. Under highly stratified conditions, two-layered flow is largely determined by the interaction of baroclinic and barotropic forcing. 

L. Janaway, D. Hawes, I. A. Sutherland, and P. Wood, Chromatography Apparatus (coil winding process and winding tnbing into a coU) UK Patent Application No 0015486.4 filed 23 June 2000. 

Fabrlcatlon/assembly of externally wound tubular membrane elements is accomplished by specially designed equipment that simultaneously and continuously winds, in helical fashion. Infinite lengths of membrane and backing material strips onto prefabricated tubular support structures. Membrane strip winding overlaps are solvent bonded during the winding process. 

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