Design of double teeth metallic card clothing for the high-efficiency carding process by computational fluid dynamics

Abstract

The design of metallic card clothing, which is one of the most important devices in the textile industry, has always been based on operational experience. With the development of types of fibers and the requirements for the quality of yarns, those principles concluded by engineers seem to be losing their efficiency. Recent research found that airflow played an important role in the card process, which means airflow should be carefully studied. Computational fluid dynamics (CFD) simulation greatly helps in the analysis of airflow because the gauge between carding elements is too narrow to put in any measuring device. In the present study, with the help of CFD simulation, the air around different carding clothing with varied tooth depth was analyzed. It was concluded that the carding efficiency improvement in card clothing with lower tooth depth may be related to more concentrated air velocity at the tooth tips. This resulted in more probabilities that fibers would get through the cylinder surface at the teeth tips, so that the fibers could be caught by flat-top needles more efficiently. With this assumption, a new generation of card clothing called “double teeth” containing two teeth in a single section has been invented. The new configuration design of card clothing was then applied in several spinning mills on an industrial scale for experiments. The results showed about a 30% improvement in production at the same quality level as conventional card clothing, which implied the usefulness of the newly applied principles related to airflow. Despite the difficulty in the study of the complex carding process, the new airflow analysis method has shown an optional and worthwhile way of thinking that could make a difference in future research in the textile industry.

Carding Behavior and Bearing Capacity of a Newly Developed Cylinder Card-Clothing Compatible with Cotton and Terylene Fibers by Nb Alloying of AISI 1090 Steel

“…The advantage of the new one is that fibers would always be held at the top area of the teeth so that the fibers have a higher probability of being caught up by a flat-top needle, which would help improve the carding performance. The theory here was verified with the invention of double-tooth card clothing, published in 2021 [10]. The newly designed cylinder card clothing seems to obey this rule worldwide from different card clothing providers, including famous European factories [11][12][13].…”

“…As discussed in this article, the wall shear stress of needles and teeth offers a promising avenue for soft materials in the shear stress of worn hard materials. Additionally, the velocity distribution provides another example of the development of double teeth [10]. More and more related physical quantities would be found to describe the carding process if we continue to focus on improving the simulation model.…”

“…The rotational/periodic symmetric boundaries can be regarded as an approximate model of the central carding region. Different from the previous study [10], the flat-top part could now represent a total repeat unit of any flat-top needle patterns, including uniform and non-uniform needle arrangements. The domain at two sides of the flat-top area restored the distance between two adjacent flat-top strips.…”

“…The carding area was a complex geometry with too many faces, so the simulation consumption was always a big problem. Thus, our group applied a simplified carding area with a uniform flat-top needle model for simulation in developing double-tooth carding clothing in 2021 [10]. In that article, the airflow distribution around tooth tips was taken as a physical indicator to describe the carding performance of metallic card clothing.…”

Card clothing with misaligned teeth for the card: Carding mechanism and application

“…20 Recently, research on the airflow affected by tooth shape has been discussed by the simulation method. 21 Therefore, simulation is becoming a practical way to find the working principal of the card machine. In this paper, we go further into the contacting chances and strength analysis between fibers and teeth with different arrangements.…”