T02A: Twist Singles

AWTA TEST CODE

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T02A

OTHER NAMES

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SINGLES TWIST

TEST METHODS

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AS 2001.2.14
ASTM D1422
ASTM* D1423
BS-F 2864
DEF(AUST)5037-A7
ISO 2061
IWTO DRAFTTM-25

IMAGE

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Semi-Automatic Twist Tester

APPLICATION

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The method is applicable to packaged single twisted (ply) yarns capable of being untwisted as well as to single twisted (ply) yarns able to be removed from fabrics. The method is NOT applicable to core-spun, open-end spun and air-vortex yarns.

PRINCIPLE

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The untwist - twist method is usually applied to single yarns. In This method the twist in a known length of yarn is removed under tension by rotating one end of the specimen. Further twist is then inserted in the opposite direction until the yarn contracts to its original length. Twist in the specimen is determined as half the number of turns registered by the twist counter divided by the length of the twist specimen.

The direct counting method as described in T02B - Twist - Folding can be used for single yarns providing fibres contained in the yarns have a mean fibre length greater than 40mm.

SAMPLES REQUIRED FOR TESTING

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Yarn from packages

1. Bulk sample

Number of cases in shipment or lot

Minimum number of cases to be selected at random

3 or less

4 to 10

11 to 30

31 to 75

76 or more

1

2

3

4

5

2. 10 yarn packages shall be selected at random from the bulk sample.

3. Smaller samples can be tested on request, but the precision of the result will be affected.

Yarn from fabrics

A minimum area of 1.5m2 of fabric.

INTERPRETATION

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Test results should be within +/-5% of the nominal twist, which is usually stated in the material specification.

SERVICE TARGET

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6 days.

COST

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See Fee List.