Apparatus for altering the length of synthetic strands

Apparatus for altering the length of a synthetic fiber strand, in the form of a continuous filament or yarn, by stretching or shrinking the same. The apparatus comprises a first strand feeding means having a driven feed roll means and a separator idler roller; a first heating means in the form of a heated roll means coaxial with said feed roll means and a separator idler roller; a second heating means in the form of a heated plate over which the strand slides; a second feeding means in the form of a driven roller and a separator idler roller; and a driven take-up spool. The strand passes around the first feed roll means and its separator idler roller and then around the heated roll means and its separator idler roller. The strand then passes around the driven roller and separator idler roller of the second feeding means, and then to the take-up spool. The second feeding means is driven faster or slower than the first feeding means depending on whether the strand is to be stretched or shrunk. The first feed roll means and the heated roll means may be of the same diameter, or they may be of different diameters if it is desired to pre-stretch or pre-shrink the strand prior to the stretching or shrinking which occurs between the first and second feeding means. The coaxial feeding and heating roll means may be integral, they may be separate rollers rigidly connected together, or the heated roller may be an idler roller driven only by the strand.