A Study of the Compression Resilience of Flexible Keyboard Fabric.pdf

1、The design principle of velvet keyboard fabric differs from multi-layer keyboard fabrics because it produces a complete piece of fabric. The multi-layer keyboard fabrics are woven separately and then laminated one over t

2、he other resulting in upper conductive layer, middle insulating layer and lower conducting layer. A velvet keyboard fabric has a structure which is composed of warp, filling and pile yams arranged in such a way that the

3、warp and filling yarns form the face and back ground fabrics joined by the pile yams which form loops perpendicular to the two ground fabrics. The face ground fabric acts as the upper conductive layer' the pile yarn acts

4、 as the middle insulating layer and the back ground fabric acts as the lower conductive layer. This procedure is cost effective as it reduces the manufacturing steps and bulk production is realized using conventional loo

5、ms resulting in a keyboard fabric characterized by good handle properties, a comfortable feel, appearance stability, durability and flexibility.
　　 Since the velvet keyboard fabric is subjected to compressive load in

6、 use; its press-touch sensitivity when the applied force is applied and compression recovery in fabric thickness when the applied force is removed are very crucial. Therefore, there is a need to understand what parameter

7、s influences the compression resilience and press-touch sensitivity so as to get the best structural parameters which optimizes the compression resilience and press-touch sensitivity of the velvet fabric. The velve keybo

8、ard fabric was then woven with the following parameters Pile height (4,5 and 6 mm), Fibre type [pile yarn (cotton & polyester)] and [ground weft yarn (cotton, employment of an elastic yarn (spandex Lycra), and cotton mix

9、ed with spandex Lycra)], Pile yarn density (9.0,18.1,27.0 and 36.2 piles/cm2), Binding type (V-and W- binding types), Pile distribution ratio (1, 2, 3 and 4), Number of metal wires (3, 4, 5 and 6), and Metal wire diamete

10、r (8, 18, 35 and 50 μm).
　　 The results show that the above parameters influence compression resilience property and press-touch sensitivity of the velvet keyboard fabric, and the structural factors have a more prono

11、unced effect as compared to effect of fibre /or yarn type. By varying the above parameters one at a time while keeping the other parameters constant it was discovered that the compression resilience and press-touch sensi

12、tivity changed and these two characteristics opposes each other, therefore there is need to strike a balance between them. For optimum results the use of polyester pile yarn, 5mm pile height, 18.1 piles/cm2 pile density,