The Study Of Techniques On The Delta-Sigma High-Speed Random Carding Machine For Spunlace Nonwoven Faric

Carding is one of the key working procedures in dry-method nonwoven fabric production and also the core of web-formation technology. Its function is to make the material into web which is made of single fibers for next procedures such as cross webbing, direct reinforce or air-webbing system. It affects the uniformity and orientation of fibers which has direct impact on the performance and use of final nonwoven product.Through the research on a new style nonwoven carding machine and the performance of the spunlace nonwoven products which is made by it, this paper presents the principle of fiber random, the principle of aerodynamic stripping system, the impact on product's quality from carding technics and the basic performance of spunlace nonwoven fabric.The impact of carding machine on the quality of spunlace nonwoven product comes from two major aspects: one is the mechanical reason, such as the gap between rollers ,the specification of wires, the design of each part, the number , kind and distributing of rollers etc. Through the research of each part, especially the Delta and Sigma parts, we find the design principle and design advantages of them. The other is the impact from carding technics, such as the speed of each roller, the speed of production line and the speed ratio between two rollers etc.The nowoven fabric is made of fiber web which is the basic aspect of nonwoven product. So, beside the uniformity requirement, the web should have more fibers of random orientation which means the difference of breaking strength in length and breadth is small. But the fiber orientation in the web which is made by normal carding machines is normally coincident. So, it needs to find certain solutions to randomize fibers in web and make web having more fibers of random orientation. This carding machine contains a certain number of random parts which can changed the fiber orientation and the triangle randomizing area is the key point to make such a change.According to a great quantity of data which was getting from production, this paper presents the researches on the properties of spunlace nonwoven fabrics and the influences of carding and spunlace technics on them. Based on mechanical properties testing and analyzing of spunlace nonwoven fabric with different kinds of fibers and fabric weights, it results as follows: the kind of fibers produces a big effect on fabrics' mechanical properties; to spunlace nonwoven fabrics, the bigger the weight is, the stronger the strength is, as well as its strength ratio in length and breadth; the entanglement coefficient is up when the weight of web is up until a certain degree; the effect of fiber randomization is improved when the speed of random roller is up until certain speed; the weight can be accurately controlled by adjusting the speed of feeding roller; the fact that the higher production speed the more flying is also an problem needed to be solved in high-yield and high speed carding machine.Based on a lot of experiments and analysis, this paper brings forward a plan in optimizing carding technics, discusses the working principle of critical positions on this carding machine (Delta random-transfer system and Sigma multi-doffer stripping system) and also points out the developing trend and technical difficulties of high-speed and high-yield nonwoven carding machine in future.