Stenter

1. Stenter Machine 1 Mazadul Hasan Shishir , Southeast University

2. Prepared By : Prepared By : Mazadul Hasan sheshir ID: 2010000400008 13thBatch (session 2009-2013) Department : Wet Processing Technology Email: mazadulhasan@yahoo.com Blog : www. Textilelab.blogspot.com (visit) Southeast University Department Of Textile Engineering I/A 251,252 Tejgaon Dhaka Bangladesh ©right

3. Main Units 3  A padder to uniformly wet-out fabrics and apply finishing agents,  Weft-straightening devices  and control equipment Mazadul Hasan Shishir , Southeast University

4. Uses 4  The stenter is a continuous types of machine and can be used before or after dyeing/printing.  The stenter frame used for following processes. Equalizing(skew and bow control) Printed design control Fabric width setting Application of finishing chemicals Drying 1. 2. 3. 4. 5. Mazadul Hasan Shishir , Southeast University

5. Process stages 5 Mazadul Hasan Shishir , Southeast University

6. Stenter Frame 6 Mazadul Hasan Shishir , Southeast University

7. Stenter Frame 7 Mazadul Hasan Shishir , Southeast University

8. Process Description 8  The selvedges are held by two endless chains typically 40 to 60 metres in length and the fabric is conveyed through a series of heated compartments or bays. Hot air is directed onto the fabric equally from above and below. The selvedges are held either on pins about 5 mm long mounted in base plates or by clips that grip the selvedges between smooth surfaces. Lubrication of the chain is important and this takes place automatically during running. The lubricant must be completely stable during continuous high-temperature operation. Mazadul Hasan Shishir , Southeast University

9. Some features 9  Stenter speeds range from only 10 m/min for heavyweight furnishings up to 100 m/min for lightweight dressgoods.  Overfeed is frequently necessary to compensate for warp way stretch in previous processing and to minimise shrinkage in washing and dry-cleaning.  The speed of the fabric through the stenter is controlled by the motion of the pin chain, but the fabric entry can be adjusted independently by the entry rollers.  Temperature uniformity over the entire area of fabric is ensured  Too low temperatures do not allow a good setting while too high temperatures and too long setting times cause yellowing (PA and elastic fibres), stiff hand (acrylics), and loss of elasticity (elastic fibres). Mazadul Hasan Shishir , Southeast University

10. Heat setting 10 The setting temperature used is above Tg. In heat setting, inter-chain bonds, such as hydrogen and dipole bonds, break. This allows the molecular chains to move and adopt new, stress-free positions. New intermolecular bonds then form with the fabric in a relaxed condition at the setting temperature. After cooling, the polymer molecules in the filaments become frozen in place. The new bonds are stable up to the heat setting temperature. The reorganized internal polymer structure, and the material’s dimensions, will be stable. Mazadul Hasan Shishir , Southeast University

11. Temperature Range 11 Mazadul Hasan Shishir , Southeast University

12. Equalizing (Skew/ Bow) 12 Mazadul Hasan Shishir , Southeast University

13. Skew and Bow 13 Mazadul Hasan Shishir , Southeast University

14. Design Deviation 14 Mazadul Hasan Shishir , Southeast University

15. 15 Mazadul Hasan Shishir , Southeast University

16. How to control it? 16 Mazadul Hasan Shishir , Southeast University

17. Weft Straightening Device 17 Mazadul Hasan Shishir , Southeast University

18. Mahlo or Bianco Location 18 Mazadul Hasan Shishir , Southeast University

19. Controling Monitor 19 1. Actual weft configuration 2. Actual distortion (in%) 3. 60min trend diagrams (skew and bow) Mazadul Hasan Shishir , Southeast University