The bobbin is the back thread used in the shuttle to form the lock stitch. The yarn is drawn off from the inside to the outside to avoid friction between shuttle and yarn. A small control opening in the shuttle allows checking the amount of bobbin yarn available in the shuttle.
- Bobbin (TDP) holds approx. 270mm of yarn lasts for approx. 70000 stitches
- Bobbin size should correspond to shuttle size – the closing of the cover should be easy. Do not use too big bobbins which have to be squeezed into the shuttles.
- The bobbin should be firm
- The close the winding of the yarn, the more yarn can be applied to the bobbin
- Other Used yarns:
- Spun polyester: NE 80/2
- Long staple cotton (long fiber cotton): Ne 80/2, 60/2, 50/2
- Bobbin size: 15x44mm
- Store yarns dust-free (cotton with short fibers is not appropriate for bobbins, that is why long staple cotton is used) and keep them clean (shuttle spring function may plug otherwise).
- Air humidity for winding and stocking of the bobbins: 45-50%
- Bobbin yarn too humid will cause bloating out of the yarn and decrease the winding capacity of the yarn
- Twisting of yarn must be appropriate too much twisting will result in snarling of the yarn
- Suggest twists:
- Nm 100/2 (tex 10 x 2) = 720 T/m
- Nm 120/2 (tex 8.3 x 2) = 900 T/m
- Nm 140/2 (tex 7.2 x 2) = 1000 T/m
- Nm 160/2 (tex 6.3 x 2) = 1300 T/m
- Twisted yarns have to be S and Z twisted: S-twisting for single threads, Z-twist for the entire thread
- Steam bobbins before use (not more than 85o C)
- Store bobbins after steaming for 3 to 5 weeks at 75% air humidity
- Stock in cardboard boxes for not more than 4 to 6 kilos (otherwise too much moisture transfer)
- Air humidity before use of bobbin: 8.5%
- Damaged or twisted spindles have to be exchanged immediately (otherwise the quality of bobbin will decrease)
- Keep bobbin winder dust-free
- Check bobbin size from time to time with the tool, especially when exchanging yarn
- Shuttle yarn has to be thinner than front yarn, too strong shuttle threads result in rough embroidery.