Showing posts with label Sinker. Show all posts
Showing posts with label Sinker. Show all posts
17 November 2010
Sinker | Sinker Operations of Knitting Machine
Sinker
The
sinker is the second primary knitting element. It is a thin metal plate
with an individual or a collective action operating approximately at
right angles from the hook side of the needle bed, between adjacent
needles.
Sinkers capable of producing loop fabric are well known in the knitting industry. In such machines the sinkers generally include a blade having an upper edge which defines a lower knitting level and a nib having an upper edge which is at an upper knitting level. Long loops are formed at the upper knitting level of the sinkers with a loop yarn and a base yarn is knitted over the blade. The sinkers may be formed and their movement controlled to cause either the loop yarn to appear on one side of a fabric and the base yarn on the other or the loop yarn to appear on both sides.
Sinkers capable of producing loop fabric are well known in the knitting industry. In such machines the sinkers generally include a blade having an upper edge which defines a lower knitting level and a nib having an upper edge which is at an upper knitting level. Long loops are formed at the upper knitting level of the sinkers with a loop yarn and a base yarn is knitted over the blade. The sinkers may be formed and their movement controlled to cause either the loop yarn to appear on one side of a fabric and the base yarn on the other or the loop yarn to appear on both sides.
In the past it has not been possible to producing loop cloth of ideal quality since loops would twist or coil making it difficult to finish a loop fabric into satisfactory velor. Furthermore loops which were supposed to appear on the front of a fabric would sometimes appear on the other side. The back of loop cloth was therefore apt to have objectionable loose protruding loops and double tuck stitches.
 |
1=Butt,2=Butt
breadth,3=Height of shank,4=Buldge,5=Neb,6=Length of neb,7=Throat
angle,8=Sinker platform height,9=Breadth of lower
shank,10=Clearance,11=Throat
Fig: sinker.
|
Sinkers Operation
1. The held loop is positioned in the throat of the sinker when the sinker moves forward and the needle moves upward for clearing. The held loop is held by the throat and hence its movement along the needle is restricted.
2. The sinker remains at its forward position when the needle attains its clearing position.
3. The sinker retracts when the needle comes down after feeding. At this stage, due to sinkers retraction, fabric or held loop is eased out. Also the sinker belly supported the fabric or held loop and hence its movements along the needle is prevented.
4. Sinker remains in backward position and the needle descends to its lowest position drawing the new loop through the old one.
5. Before the needle ascends, the sinker moves forward to push the knitted fabric a little and to hold the old loop away from the head of the needle and to be in a position to control the fabric.
1. The held loop is positioned in the throat of the sinker when the sinker moves forward and the needle moves upward for clearing. The held loop is held by the throat and hence its movement along the needle is restricted.
2. The sinker remains at its forward position when the needle attains its clearing position.
3. The sinker retracts when the needle comes down after feeding. At this stage, due to sinkers retraction, fabric or held loop is eased out. Also the sinker belly supported the fabric or held loop and hence its movements along the needle is prevented.
4. Sinker remains in backward position and the needle descends to its lowest position drawing the new loop through the old one.
5. Before the needle ascends, the sinker moves forward to push the knitted fabric a little and to hold the old loop away from the head of the needle and to be in a position to control the fabric.
15 November 2010
Basic Knitting Elements of a Circular Knitting Machine
NEEDLES
We can divide a needle into three main parts:
A. the hook, which takes and retains the thread tube looped;
B. the hook opening and closing device, that allows the hook to alternatively take a new thread and release the previous one;
C. a system allowing the needle to move and form the loop.
The needles are the most important
stitch forming elements. They are displaced vertically up and down and
are mounted into the tricks or cuts of the knitting cylinder.
There are three types of needles namely:
1. Latch needle
2. Spring bearded needle
There are three types of needles namely:
1. Latch needle
2. Spring bearded needle
3. Compound needle.
We can divide a needle into three main parts:
A. the hook, which takes and retains the thread tube looped;
B. the hook opening and closing device, that allows the hook to alternatively take a new thread and release the previous one;
C. a system allowing the needle to move and form the loop.
22 February 2010
Basic Mechanical Working Process of Sinker in Knitting Technology
The sinker is the
second primary knitting element (the needle being the first). It is a
thin metal plate with an individual or a collective action operating
approximately at right angles from the hook side of the needle bed,
between adjacent needles. It may perform one or more of the following
functions, dependent upon the machine’s knitting action and consequent
sinker shape and movement:
In Fig. 1, the protruding nib or nose of’ sinker (N) is positioned over the sinker loop of the old loop (O), preventing it from rising with the needle. On tricot warp knitting machines and single bed weft knitting machines, a slot or throat (T in Fig.2) is cut to hold and control the old loop.
- Loop formation
- Holding-down
- Knocking-over
 |
| Fig. 1 Action of the loop-forming sinker. |
The second and more common
function of sinkers on modern machines is to hold down the old loops at a
lower level on the needle stems than the new loops that are being
formed, and to prevent the old loops from being lifted as the needles
rise to clear them from their hooks.
In Fig. 1, the protruding nib or nose of’ sinker (N) is positioned over the sinker loop of the old loop (O), preventing it from rising with the needle. On tricot warp knitting machines and single bed weft knitting machines, a slot or throat (T in Fig.2) is cut to hold and control the old loop.
 |
| Fig. 2 Action of the knock-over sinker. |
The
third function of the sinker – as a knock-over surface – is illustrated
in Fig. 2 where its upper surface or belly (B) supports the old loop
(O) as the new loop (NL) is drawn through it. On tricot warp knitting
machines the sinker belly is specially shaped to assist with landing as
well as knock-over. On raschel warp knitting machines, many V-bed flats,
and cylinder and dial circular machines, the verge or upper surface of
the trick-plate serves as the knock-over surface. On some machines, the
knock-over surface moves in opposition to the descent of the needle.
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