Structure And Simulation On Raschel Lace

Raschel lace is delicate, soft and the production efficiency is also high. This kind of fabric obtains women’s deep love by its beautiful and variable pattern and effect, and it plays an important role in the female underwear sector. At present, the Raschel lace is developing promptly worldwide, particularly in China. In the 21st century, about seventy percent of the global lace is produced in China. China is not the original country of lace, but with the world economic integration and the science and technology continual development, the lace technology is widely spreading and quickly developing in China. In the near future, we can expect that the research and development center of lace will also shift to the East. That’s the good reason why studying the structure and design of Raschel lace and developing relative CAD system to suit the prompting development of Chinese market are so important and meaningful. This paper bases on the research result of lace production principle and structure characteristic, establishes the model of lace design and simulation, promoted a Raschel lace design and the simulation system with international advanced level, which help to enhance -domestic Raschel lace design significantly.Firstly, the paper systematically studied the principle of each Raschel Lace formation, and proposed a scientific classification of Raschel Lace for the first time. Mulitibar Raschel Laces are divided into five groups, i.e. inlay forming lace, fall- plate forming lace, Stitch forming lace, Jacquardtrionc Lace, Textronic Lace. Afterwards, the paper thoroughly analyzes the structure characteristic of Raschel Lace, and establishes the base for the lace design and the simulation research. The structure of Raschel lace consists of ground and pattern. It is easily to make distinguish the effect of pattern and ground structure. Based on whether the machine equips with Jacquard system, the ground of lace is divided into two kinds: one is standard structure as the common net or similar net structure, another one is fancy ground structure which is produced by Jacquard guide bar with difference pattern and thickness areas. The prominent pattern on the Raschel Lace is produced by the pattern bars. The different configuration of pattern bars of Multibar Raschel machine creates different pattern effect. Inlay forming lace has fairly smooth pattern effect. Stitch forming lace has stronger relievo effect; however, the pattern yarns have to form stitches, so the yarn which can be used is limited. The fall pattern forming lace may have even better relievo effect than stitch forming lace by more extensive pattern yarns which don’t need to form the stitches. Secondly, this paper focuses on the features of pattern structure and thoroughly analyzes the lapping movement rules of pattern bars, and puts forward a new design model for the lapping movement of inlay, fall-plate and stitch in the multibar fabric design. A multibar lace design system on computer was developed successfully based on the model. Four-point model and eight-point model are used to design inlay pattern, fall plate pattern and stitch pattern corresponding to individual feature of pattern structure. Drawing shapes are brought out corresponding to the different lappings. Furthermore, nine kinds of inlay lapping and eighteen fall-plate lapping are described mathematically. It covers all kinds of lapping shape. This model is proved to be exact, vivid and beauty and reflects the structure characteristics perfectly of multibar lace.The paper systematic studies the design methods of Raschel lace, and proposes scientific and reasonable design process of Raschel Lace for the first time. The design process includes ten steps, i.e determining the basic technological parameter, determining machine type, determining ground structure, assigning guide bars, determining threading schematic, drawing each pattern guide bar’s lapping, drawing jacquard draft pattern, selecting yarn materials, simulating fabric and outputting data. The ten steps can be selected according to the pattern, for example, the jacquard draft pattern can be omitted when designing the lace with standard ground. The ten steps can apply to all multibar raschel lace designs.Finally, the simulation models for Raschel lace is established, i.e inlay simulation model, fall plate simulation model, yarn simulation model and subsequently realizes the pattern design and simulation functions for inlay forming lace, stitch forming lace and fall plate forming lace. Different yarn deformations in the fabric are also well considered in the simulation models. In order to simulate multibar Raschel lace quickly and visually by the computer instead of costly and time taking sample production, a lot of experiments have been done by the program to optimize the simulation model. The finial CAD system which is developed on the models proves the the whole study on the Raschel lace is reliable and valuable.