| Abstract [eng] |
Spatial multilayer weft knits have been designed, for the production of which a flat knitting machine from Shima Seiki (Japan) SES-122 two-needle beds E12 gauge machine has been selected and knitted in the company Gija. The structure of the knits consists of three layers - two outer and inner filler layers, which consist of yarns overlays connecting two outer layers. The chosen research object is two groups of the following multilayer knits: 1. Spatial knits with the same amount of filler, i. e. with the same number of extensions of the inner layer, selecting different raw materials for each layer. 2. Three-dimensional knits in which all three layers are designed using the same raw materials, but with a proportional change in the quantity of extensions of the connecting threads of the inner layer. Wool 33.3 tex × 2 and 20.8 tex × 2 yarn, cotton 19.7 tex × 2 and 29.5 tex × 2 yarn, acrylonitrile (PAN) 31.3 tex × 2 yarn, polyester (PES) 42 tex multifilament threads used for knitting the patterns. The knitted samples were stabilized by hot steam using an evaporation-stabilization press "Cosmotex" (Spain). The vertical (Pv) and horizontal (Ph) density coefficients of the samples were determined, and the surface density (M) of each sample was calculated. Calculations of statistical indicators of samples were performed, the scatter of results, and possible errors were estimated. Measurements of sample thickness, air permeability, and heat exchange dynamics studies were performed. After the thickness measurements, it was found that the fiber composition and type of the yarns used for the connecting layer, the step, and the number of extensions of the connecting layer in the pattern repeat is very important for the thickness of the knits. It was found that the fiber composition of individual spatial knit layers (yarn raw material and yarn structure) has a significant effect on air permeability. It was also observed that the air permeability is also influenced by the distribution of the composition of the raw materials in the individual layers, the type of yarns and quantity of extensions of the connecting layer in the pattern repeat. In the case of the first group of samples, the best thermal insulation knits were obtained with wool, and the worst thermal insulation was obtained with samples, all layers of which were knitted from cotton yarn. In the case of the second group of specimens, the knit with the highest step and number of extensions of the inner layer in the pattern repeat had the best thermal insulation. |
