3D Knitted Preforms Using Large Circular Weft Knitting Machines

Abstract

Abstract3D-knits are typically produced on flat knitting or special circular knitting machines in a time-consuming process. The utilisation of a sewing-like pattern opens up the potential of a 10–50 times faster production on common large circular knitting machines as compared to conventional flat knitting machines. Since common large circular knitting machines are not designed for this technology, the limitations and the stability of process conditions have been rarely studied. To further proof the feasibility and increase technological maturity, agile product development is conducted. As a concept product, a sports bra with customised cups is developed and demonstrated, which is knitted in a single step in approx. 5 min using the sewing-like pattern on a large circular knitting machine. The agile process is utilised to build process knowledge, develop a methodology for product design and to defined a descriptive process terminology. In order to further accelerate and digitize the production process, an algorithm is developed and implemented to convert CAD-data into machine readable knitting structures. The paper presents the basics of the 3D-Knit one large circular knitting machines and a defined terminology. Furthermore, process knowledge is built up and from this a sequence of development steps is derived. The development of a 3D-knitted sports bra is presented as a proof of concept of the technology. Further, the first steps for digitalising the product development process are given. The results open up application possibilities in sportswear, upholstery and aerospace with increased productivity and hence cost reduction.

A Review on Knitted Flexible Strain Sensors for Human Activity Monitoring

“…[77][78][79] In addition, the circular weft knitting technique can knit sensing areas at multiple fixed locations and the resulting fabric is stable. Among them, the seamless weft knitting machine is often used to prepare sensors with local sensing areas, suitable for developing underwear, [80] sportswear, [81][82][83] knee-let, [84][85][86] elbow covers, and other products that can monitor human activities. However, there are many floats on the back of the conductive area due to the knitting technology, so it is necessary to further cut the float to avoid affecting the signal sensing.…”

Research on an Intelligent Piezoelectric Needle Selector System with Closed-Loop Fault Detection Capability

“…The selector within the circular weft knitting machine is a crucial operational component responsible for creating fabric patterns, and its performance directly impacts the production efficiency of the circular weft machine and the diversity of fabric patterns it can produce. With the continuous development of electronic technology and circular knitting computerized jacquard technology [3,4], various electronic technologies have begun to be applied to the drive and detection of selectors in circular weft knitting machines [5]. Currently, electronic selectors commonly found in the market fall into two major categories: piezoelectric ceramic selectors and electromagnetic selectors [6].…”