Stenter

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Mazadul Hasan Shishir , Southeast University

Stenter Machine

Prepared By : Mazadul Hasan sheshirID: 201000040000813th Batch (session 2009-2013)Department : Wet Processing Technology Email: [email protected] : www. Textilelab.blogspot.com (visit)

Southeast University Department Of Textile Engineering

I/A 251,252 Tejgaon Dhaka Bangladesh

Prepared By :

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Main Units

A padder to uniformly wet-out fabrics and apply finishing agents,

Weft-straightening devices and control equipment


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Uses

The stenter is a continuous types of machine and can be used before or after dyeing/printing.

The stenter frame used for following processes.

1. Equalizing(skew and bow control)2. Printed design control3. Fabric width setting4. Application of finishing chemicals5. Drying


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Process stages


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Stenter Frame


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Stenter Frame


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Process Description

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.


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Some features

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).


10The 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.

Heat setting


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Temperature Range


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Equalizing (Skew/ Bow)


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Skew and Bow


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Design Deviation


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How to control it?


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Weft Straightening Device


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Mahlo or Bianco Location


19 1. Actual weft configuration 2. Actual distortion (in%)3. 60min trend diagrams(skew and bow)

Controling Monitor
