WEB STITCHING & STITCH BONDING

By

Himanshu Gupta

Introduction Categorized under mechanical bonding

technique. Stitch bonding is a hybrid technology, which

uses elements of various technologies from non woven to sewing & knitting.

It can be done with or without addition of a thread, when no thread is used it is often termed as “Loop formation”.

Principal Locking of layers of Cross laid webs of fibres,

non woven or other flat sheet into the warp knit structure, thus combining knit fabric properties with base structure with selected mechanical & functional features for its end use.

Stitch bonding consist of pointed needles arranged in a row, moving reciprocal back & fourth into the fibrous layers synchronized insertion of stitching yarn by each penetration of needle. Latches pulls the yarn from one side to the other side.

Stitch bonding M/c

1. needle motion2. knockover and

support combs3. guide bar4. device for transport

of the web5. fabric draw-off from

the needle motion and fabrics take-up

6. device for feeding and guiding the warp threads

Mechanism

1. Penetration

2. Lapping

3. Closing

4. Knocking-over

5. Take-down

Stitch bonding systems or technique Stitch bonding of webs with stitching thread.

( MALIWATT TECHNIQUE) Stitch bonding of webs without stitching

thread.

(MALIVILIES TECHNIQUE) Stitch bonding of webs with loop formation

(MALIPOL,VOLTEX, KUNIT MULTIKNIT TECHNIQUE).

MALIWATT 1 Maliwatt machine 2 warp beam creel

3 knitting threads 4 lap layer

5 web 6 stitch-bonded material

7 pad lapper

The horizontal compound needle, which operates in conjunction with the knock-over sinker and the supporting rail, needles penetrates through the substrate which is normally a cross-laid web.

The stitching yarn, which

is inserted via the guides

into the open hooks of

the compound needles,

forms stitches that

penetrate the web.

Maliwatt application Soft furnishings, upholstery fabrics for mattresses and

blankets. Transportation cloth. Cleaning cloths, fabrics for hygiene and sanitary

purposes. Secondary carpet backing. Lining fabrics, interlining for shoes and apparel. Adhesive tapes (e.g., those used for harnessing electric

cables in automobiles) Insulating materials. Geo textiles, filter fabrics.

Properties

Malivlies

Loops formed by the thread present in the web itself.

fibres are preferably cross wisely oriented.

MALIVILIES – APPLICATION:

1. Car interior cover2. Felts or textile coverings3. Absorbents 4. Polishing cloths5. Geo textile and filter cloths6. Covering substrates and laminates7. Products for medical8. Carpet backings

Properties

MALIPOL Malipol stitch bonding systems have the following

main elements.pile yarnground fabric stitch bonding head fabric take-down and batching

The compound needles penetrate the ground fabric and the stitching or pile yarn is overlapped in the needle hook.

The pile yarn is also laid on top of the pile sinker at the same time so that a tricot racking is used to create the pile and knit the yarn into the ground structure.

Working

Malipol - areas of application blankets cleaning textiles (wiping mop) pile fabric for velcro fastening stripes lining plush and soft-toy plush bathroom sets one-sided terry fabric

Voltex

Voltex fabrics are high pile or high plush fabrics Two principal reformed elements: a ground fabric and a

web, which are continuously introduced

Application

lining fabrics soft-toy plush shoe uppers and shoe lining floor coverings upholstery fabrics.

Kunit 3-D pile fabrics distinctive folded, pile variable thickness and density if

required1. Compound needle bar2. Closing wire bar3. Knockover sinker bar4. Supporting bar5. Oscillating Brush bar6. Pile sinker bar7. Base material8. Fibre web

Multiknit base materials are one or two textile fabrics with

open-pile structure, preferably Kunit nonwovens. end product, the two nonwoven surface textiles

are interlaced by fibers, forming an uniform and tight surface, being connected by almost vertically arranged fibers.

Special advantages are high degree of volume (bulkiness) and elasticity of compression

Working

1. Compound needle bar2. Closing wire bar3. Knockover sinker bar4. Counter retaining bar5. Supporting rails6. kunit-fabric

The compound needles take the pile fibres of both fabrics to make them, in the middle between the two fabrics, into a third layer of loops.

Application 1. WADDING FOR FURNITURE

2. FILTER CLOTH3. INSULATION MATERIALS4. LININGS FOR CLOTHING5. HEAT- RETARDANT MATERIALS 6. SOUND- ABSORBING MATERIALS

WARP KNITTING

What is warp knitting Warp knitting is defined as a stitch forming process in

which the yarns are supplied to the knitting zone parallel to the selvedge of the fabric, i.e. in the direction of the wales.

In warp knitting, every knitting needle is supplied with at least one separate yarn.

In order to connect the stitches to form a fabric, the yarns are deflected laterally

between the needles. In this manner a knitting needle often

draws the new yarn loop through the knitted loop formed by another end of yarn in the previous knitting cycle

Difference b/w weft & warp knitting

Weft Knitting Warp knitting

Yarn are fed course wise direction Yarns are fed wale wise direction

Yarn supply is usually in the form of a cone or cheese

Yarn is in one long beam or small warp beams

Usually latch needles are used Latch, beard or compound needles are used

Extensibility in widthwise & lengthwise direction

It stretch in lengthwise direction

Higher shrinkage Comparatively less shrinkage property

Any no. needed One yarn is required for each needle

Warp knitting movements

Swing:- front to back

movement

Shog:- lateral movement

of guide bars

Overlap:- Movement of

guide bar to wrap yarn on

needle at back of m/c

Under lap:- movement of

guide bars to wrap yarn

on needle at front of m/c

Start of new course Start of overlap Guide bar swinging motion Return swing after overlap Old loop closing latch Knock over & underlap

movements

Applications Apparel :- Sportswear, track suits, leisure wear &

safety reflective vests. Household :- Furnishing, laundry bags, mosquito

nets. Automotive :- Car cushion head rest lining, sun

shades and motorbikes helmets. Industrial :- Pvc backing, production masks, caps

& gloves.

Thank you