Fibre placement

The materials of the thermocouples — stainless steel yam and constantan wire — are processed onto the mattress topper layer by tailored fibre placement (TFP). TFP is an embroidering technique that is used to stitch fibres and yams that cannot be used as an embroidery yarn on a basic fabric. The reasons of their non-suitability of embroidery can be their thickness, fineness, or stickiness or the material itself. The principle of the TFP method is shown in Figure 9.6. The TFP method is most suitable for large-scale manufacturing. The upper sewing thread primarily serves to fix the thermocouple... 

Figure 9.6 Principle of the tailored fibre placement method.

Automated prepreg processes automated fibre placement and automated tape layup... 

In order to bring VAT panels from design to application scenarios, a variety of manufacturing techniques have been developed. Conventional automated fibre placement (AFP) techniques use tow head mming to control the angle change. 

A collaborative project between the universities of Bristol and Bath has developed a continuous tow shearing (CTS) technique [17] for fibre placement, which uses the... 

Figure 4.9 Comparison of average thickness (solid lines) and buckling strains (dashed) for straight fibre optimum designs and variable fibre angle designs obtained using continuous tow shearing and automated fibre placement. In all cases, the panels are 250 mm wide and 750 mm long with simple supports.

Nagelsmit MH, Kassapoglou C, Gurdal Z. AP-PLY a new fibre placement architecture for fabric replacement. SAMPE J 2012 47 36-45. 

Textile structures are not just limited to the apparel sector they have moved into equipment as well, especially with composite structures such as carbon fibre reinforced composites and novel textile construction. Methods such as 3D weaving and tailored fibre placement have meant that complex structures can be manufactured with specific geometry and physical properties. 

There are obvious links between fabrication procedures, inspection methods and subsequent product durability. Some methods of manufacturing reinforced plastics produce better quality products than others, because they introduce fewer defects, or allow better control over fibre placement and orientation, or enable a higher volume fraction of fibre reinforcement to be used, or lend themselves to better quality control monitoring. 

Turner MR, Rudd CD, Long AC, Middleton V, McGeehin P, Net-shape preform manufacture using automated fibre placement. Advanced Composites Letters, 4(4), 121-124, 1995. 

Random fibre placement Dispersed short-fibre injection mould Lay-up of fibre mats Nonwoven preforms... 

The track-and-column braiding process has been used to produce braids with a solid, rectangular cross section. The production of solid braids with more complex crossshape geometry can be achieved through juxtaposition of multiple braids with rectangular cross sections. Additional fibre placements within the cross section allow certain yams to braid within specific area of the cross section only to produce a hybrid composite (Kostar and Chou, 2002 Ko et ah, 1989 Kamiya et ah, 2000). 

In conclusion, the effect of bifurcation on braid stmcture is limited to the influence zone of the zero motion column and adjacent columns only. Considering that the movement of tracks and columns, which have a minimum distance to the zero motion column, is constant across the transition, the majority of the cross section is unaffected by the bifurcation. Thus, the bifurcation conditions may be subject to more complex cross sections, such as complex cross-section geometry or fibre placement. 

Low production cost Studies on products requiring optimum fibre placement and part performance have shown that pultrusion cost is about 41% of the filament winding and 26% of the prepeg hand lay-up (Krolewski and Gutowski, 1986 Strong, 2002). About 80-90% of the cost of pultruded composites comes from the raw materials it uses. The amortized machine cost and the labour to run pultrusion machines make up only small portion of the total factory costs. 

Embroidery for technical applications - tailored fibre placement... 

With the aid of embroidery, through fibre orientation, fibre-composite components can be created to withstand complex forces. This is called tailored fibre placement, TFP. ... 

Figure 4.25 Basic principle driving tailored fibre placement (TFP) technologies.

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