Tape-winding technique

The techniques generally used for inhibition of rocket propellants are sleeve technique, tape winding technique and casting technique and their salient features are as follows  

In this technique, the material, say ethyl cellulose, is first plasticized and then a sleeve of a definite size and shape is extruded. This sleeve is applied to the grain by a special technique using ethyl cellulose cement which is prepared by dissolving ethyl cellulose in cellosolve-diethyl phthalate (1 1) mixture or ethyl lactate-butyl acetate (1 4) mixture. 

While using ethyl cellulose in this technique, plasticized ethyl cellulose is extruded into tapes of uniform thickness and width. This tape is wound to the 

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On-line consolidation techniques are commonly used in manufacturing processes, such as filament winding and tape laying. Despite differences in the machines used to implement these two manufacturing processes, similar procedures are required to ensure complete bonding between the composite layers. The basic components of on-line consolidation process are illustrated in Figure 7.2. 

Filament winding (FW) is a fabrication technique for forming reinforced plastic parts of high strength/modulus and lightweight. It is made possible by exploiting the remarkable strength properties of their continuous fibers or filaments encased in a matrix of a resinous material. For this process, the reinforcement consists of filamentous non-metallic or metallic materials processed either in fibrous or tape forms.488 489... 

The ATL and AFP processes are thus a cross between filament winding with its elaborate automated patterns of fibre laydown and unidirectional prepreg layup with its reliance on the autoclave. The use of automated robotic machinery for the layup gives increased layup speed (vital to economically manufacture these large items in feasible timescale), consistency and freedom from errors compared with manual techniques, as well as ensuring precision in the placement of the tows and tapes. 

Most carbon fibers are in the form of continuous filaments with a diameter averaging 10 They are applied unidirectionally (0°) by the processing techniques of filament winding and tape layup described in Ref. 2. Such unidirectional systems have the highest property-translation efficiency, i.e., the fraction of fiber properties translated Into the composite. On the other hand, they have low interlaminate strength because of the lack of fibers in the thickness direction. 

Automation considerations. The layup of a composite, the actual placement of plies in their expected final position in the laminate, cannot be separated from the total manufacturing process in some procedures, e.g., filament winding or pultrusion. In other techniques, e.g., automatic tape laydown or RTM, the layup process is a separate batch process and is completely separate from the compaction and cure phase. AU composite manufacturing processes can be automated to some extent, and the amount of automation depends on how amenable the optimum manufacturing technique is to total or partial automation, the capital costs of the automation machinery, eventual total number of piece parts to be manufactured, the expected cost of each, the time frame available, and a host of other factors. 

Note the constraints associated with each technique, e.g., filament winding results in non-smooth outer surface pultrusion does not normally result in a quasi-isotropic laminate. For large structures, the relative cost of the filament winding is less than one-fourth that of hand layup and less than one-half that of the best tape laying machine. Use the least expensive form of composite raw materials. 

UK), in which the basic technique is to emboss a pattern of parallel indentations onto the hot melt immediately after extrusion. This results in a series of continuous and uniform fibrils connected by relatively fine membranes extending across the film s width. The film is next divided into tapes of the required denier, and processed through drawing and winding operations. It is then twisted to produce a continuously fibrillated yarn (300-600 denier), with high tenacity (6.5-8.0 cN/ denier) and regular round cross section. 

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