TW200706715A - A method for making carbon weft knitted fabrics with reinforcing performance - Google Patents

Abstract

A novel method for making carbon weft knitted fabrics method has been proposed in this patent. A carbon composite yarn with a suitable count was produced by a wrapping method to reduce the friction and to protect the carbon fibers. By using the composite yarn, carbon knitted fabrics can be produced by the weft knitting machines. The carbon composite yarns can be made by using the twister, hollow spindle, open-end rotor, and open-end friction spinning frame. The outer sheath of the composite yarn is composed of filaments, or short, long staple yarns, which are extensible and have great resistance to abrasion. The core material is a carbon tow. Using this yarn, carbon weft knitted fabrics can be made in the plain, rib, purl or composite structures. The fabrics can be inserted with wale, course, or both wale-and-course inlaid yarns, which provide reinforcing effect to the knitted fabrics. This patent proposes an improved design for making the carbon weft knitted fabrics having a double-layer, looped structure with parallel each other. The inlaid carbon tows can be inserted in between the technical face and back layers along the course, wale, or the both directions. There are three methods to insert the inlaid yarns in the fabrics. The first is that the loop can be held down both at its head and feet by other loops in the same wale, and the carbon tow is laid in the middle of the technical face and back along the wale direction. The second method is that the carbon tow is laid in the middle of the technical face and back toward course direction. The last is that the carbon tows are laid in the middle of the technical face and back along the both wale and course directions. The wale inlaid carbon tows are placed in the middle of the technical face and back along the wale direction, and they are parallel to each other. The course inlaid carbon tows are placed in the middle of technical face and back along the course direction. The course-and-wale inlaid yarns are placed in the middle of technical face and back along the course and wale directions in an orthogonal form. With the inlaid yarns, the knitted fabrics can have a much better dimensional stability and can provide a reinforcing effect to the resulting composite materials.