Sewing Machine Feed Mechanism: Types and Functions with Images
Md. Rubel Miah
Department of Textile Engineering
World University of Bangladesh
Email: rubel099@gmail.com
Feed Mechanism of Sewing Machine:
Feed mechanism in sewing machine is the basic motion of needles, loopers and bobbins, the material being sewn must move so that each cycle of needle motion involves a different part of the material. This motion is known as feed mechanism. For general categories, there are: drop feed, needle feed, Differential bottom feed mechanism, puller, unison feed mechanism, adjustable top feed mechanism. Besides these general categories, there are also uncommon feed mechanisms used in specific applications like edge joining fur, making seams on caps, and blind stitching.
Functions:
To advance the fabric in the feeding zone of the sewing machine.
To decide the length of individual stitch (spm)
Appropriate feed mechanism is sleeted to confirm case in sewing
The simplest feed system of sewing of sewing machine still commonest.
Also known as regular feed.
Main components of drop feed mechanism are:
Throat plate
Feed dog
Presser foot
Fig: Drop feed mechanism
Problems of Drop Feed:
When two plies fabrics are sewn- lower ply moves forward by the help of feed dog but foot. So, two plies of fabric cannot move forward at the same speed. As a result, lower ply is more fed than upper ply. This is called ply shifting/differential feeding pucker/feeding pucker. Sometimes roping is occurred during making of hem for ply shifting.
It pitches of stitch s pitch of feeding dog same then fabric may be damaged for repeating contact of feed dog teeth and fabric at the same place.
Remedies:
Silk less of the operator.
Needle manual technique such that, stitch length and pitch of feed dog should not be equal.
2. Differential Bottom Feed Mechanism:
Modification of drop feed system.
In the feed mechanism the feed dog consists of 2 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”.
When the speed of the front feed dog is less “we get lacy effect because the feeding speed in greater than the delivery speed”.
Stretching and gathering of fabric can be done by this system.
Fig: Differential bottom feed mechanism
3. Adjustable Top Feed System:
In general arrangement the presser foot is in two section.
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, the 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: With drop systemFig: With differential bottom feed
Fig: Adjustable top feed system
4. Needle Feed System Mechanism:
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 1 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 bath needle and feed dog should be changed.
Fig: Needle feed mechanism
5. Unison Feed System Mechanism:
AKA “walking foot system because the presser foot has two independently driven section; the holding and the holding and the feeding feet.
Mode by combination of needle feed and positive top and bottom feed.
In this system one presser foot is inside the other presser foot and gives movement at different times.
The inside presser foot and needle are driven at the same time toward the same direction.
No possibility of ply shifting.
Suitable for sewing stitch fabric and for bulk seam in heavy weight materials.
Normally not so used unless special case.
Fig: Unison feed
6. Puller Feed Mechanism:
Modification of drop feed system.
A pair of rollers used.
These rollers give a pulling motion on the fabric behind the presser foot.
Top roller is generally driven by machine whitest the lower one moves due to control and presser of the top roller.
The surface speed of puller roller is slightly higher than the feed dog speed to presser ply shifting roping.
Useful in multi needle machine specially for W/B making.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
