Treatment of yarns

Claim 2

A process for relaxing a running continuous filamentary yarn composed of thermoplastic polymeric material, wherein the yarn is entrained in and tensioned by a stream of unheated gas passing therewith into a heated enclosure wherein it is caused to assume a helical or zigzag path out of contact with any solid part of the enclosure and wherein the gas pressure falls together with the tension in the yarn.

Claim 3

A process according to claim 1 wherein the enclosure is heated with a counter-current flow of heated gas.

Claim 4

A process according to claim 1 wherein the enclosure is heated with a co-current flow of heated gas.

Claim 5

A process according to claim 1 wherein the enclosure is heated by electrically heating the walls of the enclosure.

Claim 6

A process according to claim 1 wherein the yarn has an inherent retraction tendancy in the unrelaxed state.

Claim 7

Process according to claim 5 wherein the yarn comprises conjugate filaments with the components arranged in side-by-side fashion.

Claim 8

Process according to claim 5 wherein the yarn comprises filaments which have been asymmetrically heated.

Claim 9

Process as in claim 5 wherein the yarn comprises conjugate filaments with the components arranged in eccentric sheath-core fashion.

Claim 10

Process as in claim 5 wherein the yarn comprises filaments which have been asymmetrically cooled.

Claim 11

Process as in claim 5 wherein the yarn comprises filaments which have been false twisted.

Claim 12

A process according to claim 1 wherein the heating zone has a temperature of 180*-250*C.

Claim 13

A process according to claim 1 wherein the thermoplastic polymeric material is selected from the group consisting of polyesters, polyamides, polyolefines, and copoloymers within and between these classes.

Claim 14

A process for relaxing a running continuous filamentary yarn of thermoplastic polymeric material comprising: entraining the yarn in and tensioning it by a pressurized stream of unheated gas; passing the yarn and stream of unheated gas into one end of a heated tubular enclosure of relatively large cross section to thereby expand the stream and decrease the tension in the yarn; moving the yarn in a helical or zigzag path through and relative to the enclosure; and withdrawing the relaxes yarn from the opposite end of the enclosure.

Claim 15

A process for relaxing a running continuous filamentary yarn of thermoplastic polymeric material comprising: entraining the yarn in and tensioning it by a pressurized stream of unheated gas; passing the yarn and stream of unheated gas into one end of a heated tubular enclosure of relatively large cross section to thereby expand the stream and decrease the tension in the yarn; moving the yarn in a helical or zigzag path through and relative to the enclosure; and withdrawing the relaxes yarn from the opposite end of the enclosure.

Claim 16

A process as in claim 13 wherein the yarn enters the enclosure through a rotating or oscillating passageway to thereby produce said helical or zigzag path.