Pakspiny | Drawing Machine Element | Drawing Creel Setting |Finisher Drawing Creel Setting.

  Drawing Machine Element

• Ø  Sliver feed

 The running performance of the material in the creel is critical to the draw frame efficiency and the delivered sliver quality. Operator practice and machine set-up have to be carefully monitored.

• Ø  Creel height

 Creel height should be sufficient to allow a sliver balloon to develop between the top of the material in the can and the creel guide. A minimum clearance of 500 mm is preferred. Avoid “dragging” the slivers across the top of the cans. Sliver stretching occurs which is very undesirable. Additionally, slivers dragging over the can edge disturbs the sliver and creates defects which will be seen in the yarn.

• Ø  Block creeling

 If the length of sliver in the cans in the draw frame creel is consistent, block creeling is frequently preferred. Draw frame efficiency is increased because of reduced stops due to sliver run-out. With no sliver splices due to creel can changes, the delivered sliver is of a higher quality and creates fewer stops in the downstream processes. Bad splicings in the creel can create chokes at the condenser, or undrafted pieces in the delivered sliver that cannot be drafted in ring, air-jet or Vortex spinning. Removal of the creel splicings after drafting produces the best sliver quality. With block creeling, the creel sliver splicings are run through the draw frame into the can and then removed from the top of the can.

• Ø  Random creeling

 When a plant selects to random creel, the creel sliver splice is not normally removed. Therefore the operator has to be taught how to make a splice, which will be sufficiently strong to be transported through the creel, but be soft enough to be drafted out in the draft zone. Avoid damaging sliver by reaching down the side of the can to find the sliver tail when it is to be spliced to the sliver in the following can. If a sliver end is laid into an adjacent sliver and that is then used to pull the sliver end through the machine, care must be taken to ensure that the slivers are correctly arranged in the rake.

Some operators are required to pull the new sliver over the creel through the rake and the fold the end into an adjacent sliver. This system can work well as long as the sliver and the end are not compacted and difficult to draft.

• Ø  Sliver splicing technique

 Prepare the sliver ends to be spliced by removing a Vee shaped portion about 2 to3 inches long. Overlap the Vee portions of each sliver to form a relatively uniform joint. Work the fibers in the joint by lightly pulling sideways to create an integrated splice. Squeeze the joint together and roll slightly between the palms of the hands to develop some sliver cohesion. Do not roll and twist the splice, or wet the palms of your hands to make the slivers stick together. The splice should be draftable and not cause a hard slub.

• Ø  Static creel

In the static creel the slivers have to be pulled from the cans over the guides and into the draw frame. It is very important to minimize drag angles over bars and guides. It is particularly bad when the sliver is pulled through a ring or over a bar and there is an angle of wrap of almost 180 degrees. Position the cans to permit the sliver path to be as direct as possible. Remove all rough places that cause slivers to hang. Avoid placing cans so that the sliver balloons become entangled.

• Ø  Power creel

 The power creel is provided to reduce the tension forces in the sliver. The sliver is pulled up from the can by a lifting roll and is then pulled to the feed roll. The drive to the lifting rolls can be varied so that there is only a slight sliver tension and no overfeed. To find the preferred tension, reduce the tension in the creel until the sliver is slightly overfed and then increase the tension by one small step. As the speed of the machine is changed or the material is change it is usual to have to adjust the creel tension.

• Ø  Sliver in-feed and jockey rolls

 The jockey rolls driven by the In-feed rolls feed slivers to the drawframe. Normally there are two slivers under each jockey roll. If a sliver is missing the metal jockey roll should touch the in-feed roll and activate the stop motion. The jockey rolls must be free to move. There should be 1.0 mm clearance between each stop pin and the jockey rolls. When roll clearers are provided for the sliver in-feed it is important that they be kept clean. 

 

Adjustment of Jockey Roll

  

 Ø  Sliver tension

 It is important that the sliver tension should as low as possible but it should control the sliver movement. Reduce tension until slivers are loose and then increase the tension by one step. Check that slivers do not roll and cross as they move through the machine. Slivers should not be stretched.