Page 206 - CITS - Fashion Design Technology - Trade Theory

FASHION DESIGN & TECHNOLOGY - CITS

2 Differential Bottom Feed Mechanism:
• Modification of drop feed system.
• In the feed mechanism the feed dog consists of two section one at back and one at front of the needle.
• Mechanism of each section of feed dog is like the drop feed system. But the speed of each part can be
adjusted separately.
• Extensively used for stretchy materials.
• When the speed of the front feed dog is higher than the back-feed dog. The bottom ply is pulled by the back-
feed dog but this will overcome by the greater speed of the front feed dog. So, less possibility of shifting.
• Stretching and gathering of fabric can be done by this system.(Fig 2)

Fig 2

3 Adjustable Top Feed System Mechanism:
• In general arrangement the presser foot is in two sections.

• One holding the fabric in position while the needle form the stitch and the other having length on the lower
side and moving or waking in such a way that the top ply is taken along, positively while needle is out of the
materials.

• In sewing machine, this feed mechanism can be used with both drop feed and differential bottom feed.
• Combination of adjustable feed and differential bottom feed can make top ply gathering or the gathering of
bottom ply. (Fig 3)

4 Needle Feed System Mechanism (Fig 4)
• Another name of needle feed mechanism is “Compound feed”.
• Needle itself moves forwards and backward.
• Needle penetrates the fabric enters into the note of the feed dog and for the advance movement of one stitch
length of fabric feed dog and needle pass the fame distance at the same time.
• Then needle rise up and moves to form the next stitch with one step advance.
• Practically useful in bulky sewing situation such as when quilting through the fabric, wadding and for slapping
fabrics
• For the change of stitch length, setting of both needle and feed dog should be changed.

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CITS : Apparel - Fashion Design Technology - Lesson 25 CITS : Apparel - Fashion Design Technology - Lesson 25