Welcome To The pre-project

Presentation On float & tuck stitches

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Submitted to-

Mr. A.K.M. Mobarok Hossain

Assistant Professor

Department of Textile Engineering

Submitted by-

Kazi Sabbir Ahmad

I.D: 09.02.06.053

&

Nusrat Jahan Moon

I.D: 09.02.06.098

4TH YEAR 2nd SEMESTER

Department of Textile

Engineering

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Knitting

According to the Textile Terms & Definitions “Knitting is the process of forming a fabric by intermeshing of loops of yarn”.

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Stitches

There are three principal stitches which are utilised in knit fabrics:

Knit

Tuck

Miss

These three stitches, or combinations of them appearing in the same fabric, form the basis of all knitted fabrics.

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Stitches

These different stitches are produced by controlling the height of the needles and the individual selection of needles enable knit, tuck or miss stitches to be formed.

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Lets come to know about

Needle

positions for the

production of three stitch

types

7 Fig : Three needle positions for the production of three stitch types.

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Lets come to know

How needle moves up &

down

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Knit Stitch When the needle is raised sufficiently high by the camming action to obtain the yarn in the hooked portion of the needle & the old loop is below the latch i.e., old loop is cleared, a knit stitch will be formed as the needle descends.

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Float Stitch

A miss loop occurs only if the yarn is presented to the needle but is not

taken by it. Here the needle is not activated upwards to receive the yarn that is presented to it & hence it will retain its old loop in the hook.

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Loop formation process of float stitch

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Maximum possible number of float loops

Under normal take-down tension & with normal yarn extensibility, the maximum number of successive floats on one needle is four before tension causes yarn rupture & needle damage.

Six adjacent needle is usually the maximum number for a continuous float because of the reduced elasticity & problems of snagged threads.

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Properties & effect of Float Stitch

A single float stitch has the appearance of a U-shape on the reverse of the stitch.

Structures incorporating float stitches tend to exhibit faint horizontal lines.

Float stitch makes the fabric narrower than equivalent all knit fabrics because the wales are drawn closer together by the floats, thus reducing width-wise elasticity & improving fabric stability.

The structure also becomes less extensible than either knit or tucked stitch structure because less yarn is available for extensibility which is possible with the looped structure.

Fabric also becomes lighter in weight because minimum yarn is used in construction of the structure with float stitches.

For the same reason the fabric may appear flimsy or less rigid compared to one with knit stitches all over.

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Application of float stitch

• Mainly float stitch is used for designing, when an unwanted colored yarn is to be hidden from the face side by allowing it to float at the back side.

• Combination of knitted and short float produces a fabric that does not ravel from the edge and for this reason they are used in welts of stockings.

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Tuck Stitch

When the needle is raised by camming action to obtain yarn in the hook,

but it is not raised high enough to clear the previously formed loop below the latch, the needle will have two loops in the hook, & a tuck stitch will be formed when it knits at next course.

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Lets come to know

Loop

formation process of tuck stitch

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Maximum possible number of tuck loops

• Successive tucks on the same needle are placed on top of each other at the back of the head of the held loop and each, in turn, assumes a straighter and more horizontal appearance and theoretically requires less yarn. Under normal conditions, up to four successive tucks can be accumulated before tension causes yarn rupture or needle damage. The limit is affected by machine design, needle hook size, yarn count, elasticity and fabric take-down tension.

• Dependent upon structural fineness, tucking over six adjacent needles is usually the maximum unit before snagging becomes a problem.

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Properties & effect of tuck stitch

• Tuck stitches appear on the back of a fabric and may be recognised as an inverted V, sometime elongated for two or more courses, depending on how many times the stitched was tucked.

• Tuck stitch structure shows a faint diagonal line effect.It is identifies as its head looks like a hump.

• Tuck stitches tends to reduce the length of the fabric and increase its width (Wales are pushed apart), resulting in the fabric being thicker (yarn from the tuck stitch lies on top of the preceding stitch) with less extension in the width.

• Tuck stitched structure is more open & porous than the knit stitched fabric.

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Application of tuck stitches

The tuck stitch is used in knitted fabric to create design effects in color, raised surface texture, or a hole or eyelet effect.

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Any questions???

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Thank you all

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