Postal address : Bronte Works,  Thornton, Bradford,  W.  Yorkshire    BD13 3HD,  Great Britain 

FAX                 :             44(0)1274 831111

Electronic mail:          General Information: equiptex@globalnet.co.uk

Telephone      :             44( 0)1274 831000

 1 PURPOSE AND FIELD OF THE APPARATUS

The purpose of the apparatus is to determine the twist of  thread or yarn, of a specific length, produced by a spinning process.

Several test methods are known to be suitable for determining the twist in   threads and yarns.

Full Untwist

The yarn at a free clamping length of 25mm or  thread at a free clamping length of 500mm is clamped in the apparatus subjected to prelaod equivalent to the weight of 500m of yarn or cotton thread. The clamped-in sample is twisted in the direction contrary to the original twist until the staple fibres are parallel with each other. The turns of twist obtained from the counter are converted to 1m.

Determination of turns of twist with thread tension meter

When the thread tension meter is preloaded, the pointer should settle on zero after clamping. The yarn is untwisted, then further twisted until the pointer repeatedly settles on zero. The value read off the counter represents the turns of twist per 1m if the original test length was 1/2 m.

Determining the turns of twist of the fore-thread

When determining the turns of twist of the fore-thread that forms to composite cotton thread, then untwisting of the composite cotton thread is followed by reducing the preload to the extent corresponding to one single cotton thread. Then all the fore-threads but one will be cut near the clamping jaws.

The free clamping length of the fore-thread - changed in relation to the 500m - shall be determined at reduced preload by reading off the scale of the pretensioning device.

The yarn is untwisted. Determine the turns of twist of the fore-thread according to the already described method and convert the value for 1m, based on the clamping length determined according to the previous section.

 Determining the turns of twist of a cotton thread-branch

When the turns of twist of the yarn forming the cotton thread or fore-thread are to be determined, then the cotton thread or fore-thread should be clamped between the clamping jaws set to the specifies free clamping length more loosely then necessary. The cotton thread or fore-thread should be completely untwisted, then all yarns but one are cut near clamping jaws.

The uncut yarn, thread-branch, is clamped at al length of 25mm, while applying the suitable preload and tested as described before. For adjustment of the accurate length only the rotary clamping head should be opened.

2 PRINCIPLE OF OPERATION AND CONSTRUCTION

The apparatus is suitable for determining the turns of twist of cotton thread or yarns with the application of various methods. The sample clamped in the stationary and rotary clamping heads (1,2) is twisted in or untwisted manually or by motor drive according to the test methods.

In case of motor drive, speed of the rotary clamping head is infinitely variable.

The number of rotation, both in manual or motorised driving mode, counts a built-in zero-reading instrument (3).

For carrying out the various tests, the apparatus is made suitable by the pretensioning device (4), the thread tension meter (5), the magnifier (6) and the bobbin carrier (7).

3 TECHNICAL DATA AND ACCESSORIES

Clamping length 10-500mm

Weights from 0 - 40 grms.

Magnifying glass

Number of digits on the counter 5

Net weight 12 kg. Gross weight 20 kg.