DETERMINATION OF TENSION FOR ARAMID AND CARBON YARNS WHILE WEAVING INDUSTRIAL FABRICS

Resulting from researches conducted to determine tension for para-aramid, meta-aramid, and carbon multifilament yarns during their contact with the operative parts of the weaving looms as part of the industrial fabrics formation process, we have found out that in threading areas the tension is increasing driven by variation of values of the friction forces in the contact area. It has been proven that tension degree of para-aramid, meta-aramid, and carbon multifilament yarns before industrial fabric formation area is influenced by (1) tension before cylindrical guide surface of an operative part, (2) radius of the cylindrical guide surface curve of the operative part, (3) contact angle between yarns and cylindrical guide surface of an operative part, (4) mechanical, physical and structural properties of para-aramid, metaaramid, and carbon multifilament yarns. It allowed (yet at the initial stage of design of technological process of industrial fabric formation) to determine para-aramid, meta-aramid, and carbon multifilament yarns tension before formation area depending on (1) form of threading line for yarns at the weaving loom, (2) mechanical, physical and structural properties of para-aramid, meta-aramid, and carbon multifilament yarns and industrial fabrics. The paper contains experimental research of interaction of para-aramid, metaaramid, and carbon multifilament yarns and cylindrical guide surfaces of the operative parts of automatic weaving looms. Based on experimental researches regression dependencies have been obtained between para-aramid, meta-aramid, and carbon multifilament yarns tension value after cylindrical guide surfaces of the operative part and (1) tension before cylindrical guide surface of the operative part, (2) radius of the cylindrical guide surface curve of the operative part, (3) contact angle between yarns and cylindrical guide surface of the operative part. Consecutive application of these regression dependencies allows to determine para-aramid, meta-aramid, and carbon multifilament yarns tension before industrial fabrics formation area. Analysis of regression dependencies allowed to find out values of technological parameters when para-aramid, meta-aramid, and carbon multifilament yarns tension before industrial fabrics formation area will be of minimum value. It will allow to minimize tension of para-aramid, metaaramid, and carbon multifilament yarns while manufacturing resulting in (1) yarn breakages reduction, (2) better productivity of weaving looms due to reduced stoppage time, (3) improved quality of manufactured industrial fabrics. Therefore, we can argue that suggested technological solutions are practically attractive. In view of this, it is reasonable to say that it is possible to directionally regulate the process of para-aramid, meta-aramid, and carbon multifilament yarns tension change while manufacturing industrial fabrics on the weaving looms through selection of values of guides’ geometrical parameters.