Cobulked continuous filament heather yarn method and product
AssigneeE. I. Du Pont de Nemours and Company
InventorWilliam T. Windley
Life of this patent
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Abstract
An improved method for making a continuous filament heather dyeable yarn involves cobulking in a hot fluid jet process a first unbulked yarn with a second differentially dyeable previously bulked yarn. The method enhances differential dyeability in the product when both yarns have a common type of chemical dye site and the second yarn has a greater concentration of those dye sites than the first yarn.
Claims23
An improved composite cobulked continuous filament yarn containing a first oriented continuous multifilament yarn which has been bulked in a hot fluid jet process simultaneously with a second oriented continuous multifilament yarn, the filaments of both yarns being randomly intermingled throughout the length of the composite yarn and having random three-dimensional curvilinear filament crimp with frequently alternating regions of S and Z filament twist, the filaments of said second yarn being from about 4% to about 20% longer in said composite yarn than the filaments of said first yarn, wherein the improvement comprises:
- the filaments of said first and second yarns being of polymers containing the same type of chemical dye site with the filaments of said second yarn having a substantially greater concentration of said dye site in equivalents per unit weight of polymer than the filaments of said first yarn, thus providing differential dyeability, and the filaments of said first yarn and of said second yarn each comprise from about 25% to about 75% of the total denier of said composite yarn.
In a method of producing a composite cobulked continuous filament yarn containing filaments of a first oriented continuous filament yarn and of a second oriented continuous filament yarn in which the filaments of said second yarn are longer than the filaments of said first yarn said method including the steps of (1) feeding said first yarn in an undrawn state at a controlled speed to a pair of heated draw rolls, (2) wrapping said first yarn around said draw rolls a sufficient number of times to avoid slippage thereon and said rolls being driven at surface speed at least twice the feeding speed of said first yarn thereby applying tension to and drawing to molecularly orient said first yarn, (3) also feeding to said pair of draw rolls from a yarn package at a tension of less than 1.0 grams per denier said second yarn having a lower shrinkage potential in a hot gas bulking jet than said first yarn, (4) wrapping said second yarn around said draw rolls to prevent slippage thereon, (5) bringing said first and second yarns together and forwarding the combined yarns in a high velocity stream of hot turbulent fluid in a confined space which randomly crimps and entangles the filaments thereof and thereby forms a composite cobulked yarn in which the filaments of said second yarn are from about 4% to about 20% longer than the filaments of said first yarn, (6) removing the cobulked yarn from the stream of hot fluid and cooling it at low tension while the filaments are in a crimped condition to set crimp in the filaments and (7) winding the cobulked yarn into a package under tension, the improvement for making a heather dyeable yarn comprising:
- feeding to said draw rolls as said second yarn a heat-relaxed yarn containing crimped filaments which filaments are differentially dyeable with respect to the filaments of said first yarn and which filaments constitute from about 25% to about 75% of the total denier of the cobulked yarn.
Dependencies are inferred from the claim text.