Compacting roller

In fiber placement, a moving head is mounted to a multidegree of fieedom carriage. The fiber placement head is designed to cut and place each tow individually. The head may also include a controlled heat source and compaction roller for in situ consolidation. Tow placement with in situ consolidation has made it possible to place preimpregnated tape along nongeodesic paths, manufacture parts with concave sections, and to locate ply dropoffs precisely. 

Fig. 12 Roller compaction compacts. Roller compactor feed screw designs twin feed screw and single feed screw. (Courtesy of R. W. Miller, personal files.)...

In the case of wider rolls it is necessary to take special measures that result in sufficiently uniform overall distribution of the feed. A simple way to improve the quality of border zone briquettes is shown in Figure 289. The reduced feed rate is compensated by pockets with smaller volume in the two outer rows. Smooth compacting rollers are sometimes finished with a concave surface to accomplish the same effect. 

Fig. 9 Diagram of the extruder Europresse , 1970 1. compaction roller, 2. feed roller, 3. discharger, 4. pressure head...

Equipment used for high-pressure agglomeration (a) compacting roller press, (b) briquetting roller press. 

Compared with the three other semi-finished materials, the tapes are fully consolidated (Fig. 7.16), that is, the micro and macro impregnation are completely done. FuUy consolidated tapes are available on the market with fiber volume contents of up to 60% and even higher. Due to the not applicable impregnation process the winding speed can be higher in comparison to the other winding patterns. The heating zone melts the polymer and the tension (Fig. 7.6) or compaction roller (Rg. 7.7) presses the filaments on the mandrel. 

For processing fully consolidated tape materials the process simulation tool ProSimFRT has been developed at IVWProSimFRT enables simulation of the component quality depending on the void content and the surface roughness. The simulation can be used for tape winding as well as tape placement processes using a compaction roller. 

If compaction is required to satisfy a specified density or cone resistance then field trials are normally executed on site to optimise, for instance, the number of passes for compaction rollers or the energy and centre-to-centre distance for vibroflotation equipment. Extensive monitoring and testing as outlined above is then a requirement. 

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