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Transcript of KNITTING Complete
A diversity of constructions, and the variety of fibres and finishes available.
Generally soft and light weight .
Good drapability .
Knitted fabrics conform to the figure without constricting the wearer.
A high order of wrinkle resistance.
Creases in knitted fabric brush right out.
The knitted structure is porous.
It allows the skin to breathe freely.
Its elasticity permits greater freedom of body movements
Ease of care .
Knitted apparel launders without difficulty.
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Casual wear (comfort)
Technical textiles application (medical textile such as hernia mesh, vascular grafts, composite structures, such as nose cones for supersonic aircrafts)
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1. Woven fabrics are constructed by the interlacing of two or more sets of yarns, which does not allow the fabric to stretch to any marked degree unless it is specially stretch -woven . If a certain amount of stretching is necessary, woven fabric must be cut on the bias that is, in a diagonal direction . Even then the fabric can be stretched only in the direction of the diagonal cutting .
The advantage of stretch ability in knitted fabrics is an important consideration where fit and comfort are concerned they fit the figure but do not bind it .
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2. Knitted fabrics also give warmth because of the insulative air pockets contained in this type of construction .
Yet they are porous and provide breathing comfort because body movements cause the loops to expand and contract, thus pushing air through close-fitting garments .
However , unless the fabric is heavily napped or foam laminated, it is not windproof .
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3. Knitted fabrics are very absorbent , light in weight, and wrinkle -resistant .
4. It is usually unnecessary to iron them after packing and laundering .
5. However they may shrink considerably more than woven cloth unless special techniques and shrink -proofing processes, such as Pak -nit or permasized are used.
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4. Certain kinds of knitted fabric have one serious disadvantage : if one of the loops breaks , a hole is made, which starts a run .
This disadvantage can be eliminated by variation in the stitch, which protects the fabric from raveling if any single stitch is broken .
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5. Some knitted fabrics tend to lose their shape and sag.
This tendency can be avoided by using a more closely constructed knit, giving the yarn a tighter twist, and using such special techniques as the double knit .
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6. Designs can be changed very rapidly in various types of weft knitting .
Therefore , responses to changes in fashion demands can be made much more quickly than is possible with weaving .
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Basic Definitions and Understandings
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basic unit of knitted structure.
consists of a head (H) and two side limbs or legs (L).
At the base of each leg is a foot (F), which meshes through the head of the loop formed at the previous knitting cycle
The yarn passes from the foot of one loop into the foot and leg of the next loop formed by it
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When one loop is drawn through another, loop stitch is formed.
The loop is the fundamental element of all knitted fabrics. It is a basic unit consisting of a loop of yarn meshed at its base with previously formed basic units (stitches)
The stitch is the smallest dimensionally stable unit of all knitted fabrics. It consists of a yarn loop, which is held together by being intermeshed with another stitch or other loops
Stitch density is the number of stitches per unit area of a knitted fabric (loops / cm 2)
Stitch length is the length of yarn in a knitted loop
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A needle loop is one which has been drawn through a previous loop
The upper part of the loop produced by the needle drawing the yarn
A sinker loop is one which connects adjacent needle loops.
The lower part of the knitted loop is technically referred as sinker loop connection of two legs belonging to the neighboring stitches lying laterally.
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Face Loop: During loop formation, when the new loop emerges through the old loop from back to the face (or front) side
Back Loop: If the new loop passes from the face side to the back side of old loop, it is called as back loop or weft purl loop
Open Loop: loop forming yarns does not cross at the bottom of the loop.
Closed Loop: the legs of the loop cross so that the loop closing takes place.
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The series of loops that intermesh in a vertical direction are known as 'Wale'. i.e. head to feet direction.
The loops that are inter -connected widthwise are
feet to feet direction.
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A knitted fabric is technically upright when its courses run horizontally and its wales run vertically,
with the heads of the needle loops facing towards the top of the fabric
and situated at the bottom of the fabric.
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Gauge is the term used to describe the needle spacing
It can be defined as the number of needles per unit length.
Three chief systems for representing the machine gauge:
The gauge is the major factor in determining the fabric density and appearance.
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Needles and Loops
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Three types of needles
coarser in dimensions
swinging action of the latch may cause damages to fine filament yarn
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Three types of needles
finer in cross section
requires additional element (presser)
superior knitted stitches
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Three types of needles
no yarn strain
high speed and high productivity
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Parts of Needls
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Types of Stitches
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There are three basic knitted stitches:
MISS (float or non -knit)
which form the starting point for the entire range of weft knitted structure
A knitted loop stitch is produced when a needle receives a new loop and knocks over the old loop that it held from the previous knitting cycle. The old loop then becomes a needle loop of normal configuration.
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A float stitch or welt stitch is composed of a held loop, one or more float loops and knitted loops.
It is produced when a needle holding its old loop fails to receive the new yarn that passes, as a float loop, to the back of the needle and to the reverse side of the resultant stitch, joining together the two nearest needle loops
knitted from it.
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A tuck stitch is composed of a held loop, one or more tuck loops and knitted loops
It is produced when a needle holding its loop (T) also receives the new loop, which becomes a tuck loop because it is not intermeshed through the old loop but is tucked in behind it on the reverse side of the stitch.
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