Abstract This invention concerns with a process for the preparation of a yarn package which comprises a plurality of polyurethane elastic yarns wound up on a single bobbin. The yarns are arranged substantially in a plane when seen laterally of the yarn group and provisionally bonded together for providing the possibility of re-separation into the constituent yarns at a later rewinding stage of the package. According to the invention, a plurality of groups of multifilaments comprising essentially polyurethane as extruded are passed through a corresponding number of false twisters, so as to group the respective filaments together to such a degree that the related filaments are partially fused together to set a mutual core-to-core material communication, yet having a solidified surface skin except the thus realized material communication areas on the filaments. Then, at least two of the yarns of multifilaments are jointly passed through a skew-grooved traverse for provisionally bonding these yarns together so as to realise a skin-to-skin co-bonding, for ready for winding into a yarn package on a single bobbin tube.
Process for the preparation of a yarn package on a single bobbin having a plurality of elastic yarns wound thereon, comprising the following steps of: extruding a plurality of groups of multifilaments comprising essentially polyurethane material through a spinneret; passing each of said multifilament groups through a false twister, preferably a false twisting ring for grouping each of the filaments in the group into contact with at least one other filament in the group with said filaments having surfacesolidified skins except in the area of contact with other filaments in the group; passing at least two of the yarns of said multifilament group through a skew-grooved traverse guide at a traverse angle 7*15* for provisionally bonding these yarns together through skin-to-skin bonding; and winding these skin-bonded yarns on a rotating single bobbin at a residual percentage of elongation of about 5-15 percent with the bond being of such a nature that the yarns may be readily separated at a peel-off angle less than 28 degrees during a subsequent rewinding of said yarns.
Claim 2
Dependent Claim
172 words
Process for the preparation of a yarn package on a single bobbin having a plurality of elastic yarns wound thereon, comprising the following steps of: extruding a plurality of groups of multifilaments comprising essentially polyurethane material through a spinneret; passing each of said multifilament groups through a false twister, preferably a false twisting ring for grouping each of the filaments in the group into contact with at least one other filament in the group with said filaments having surfacesolidified skins except in the area of contact with other filaments in the group; passing at least two of the yarns of said multifilament group through a skew-grooved traverse guide at a traverse angle 7*15* for provisionally bonding these yarns together through skin-to-skin bonding; and winding these skin-bonded yarns on a rotating single bobbin at a residual percentage of elongation of about 5-15 percent with the bond being of such a nature that the yarns may be readily separated at a peel-off angle less than 28 degrees during a subsequent rewinding of said yarns.
Claim 3
Dependent Claim
54 words
The process as set forth in claim 1, wherein said multifilament group is kept in sliding contact with the false twisting ring substantially in the manner of point contact, and led to leave therefrom at an outlet angle of 4*-45* as measured relative to the inelt passage of the yarn to the false twister.
Claim 4
Dependent Claim
27 words
The process as set forth in claim 1, wherein the yarns are guided through a skew groove of the traverse guide having an inclination angle of 5*-10*.