False twist texturing machine

A false twist texturing machine comprising:

• a false twist device for imparting yarn with a false twist;
• a first feed roller arranged upstream from the false twist device;
• an upstream side yarn tension control device that senses yarn tension upstream of the false twist device and that automatically controls rotation speed of the first feed roller in respect to the sensed yarn tension such that the yarn tension on the upstream side of the false twist device is maintained within a fixed range;
• and
• a downstream side yarn tension control device for automatically controlling operation of the false twist device such that yarn tension of the downstream side from the false twist device is maintained within a fixed range.

A false twist texturing machine comprising:

• a false twist device for imparting a yarn with a false twist;
• a first feed roller arranged upstream from the false twist device;
• and
• a yarn tension control device operative to automatically control the rotation speed of the first feed roller in response to yarn tension on the upstream side of the false twist device;
• and
• means for sensing yarn tension on the downstream side of said false twist device, wherein the yarn tension control device is a yarn tension control device that automatically controls the rotation speed of the first feed roller such that the ratio of the yarn tension on the upstream side of the false twist device to the yarn tension on the downstream side from the false twist device is maintained within a fixed range.

A false twist texturing machine comprising:

• a false twist texturing unit for imparting yarn with a false twist;
• a heater arranged on an upstream side from the false twist device;
• a first feed roller arranged on the upstream side of the heater;
• and
• a yarn tension detection unit operative to detect the yarn tension between the heater and the first feed roller.

A false twist texturing machine comprising:

• an upstream side yarn tension detection unit operative to detect yarn tension on an upstream side of a false twist device;
• a downstream side yarn tension detection unit operative to detect yarn tension on a downstream side of the false twist device;
• and
• a determining unit for determining whether or not the yarn quality is satisfactory based upon a comparison of the detected outputs of the upstream side yarn tension detection unit and the downstream side yarn tension detection unit.