web stitching & stitch bonding warp knitt
TRANSCRIPT
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