LENO WEAVES

WHAT IS SELVEDGE TERM?

The basic function of selvedge formation is to lock the outside threads of the fabric or of a piece of cloth, so that it could be prevented from fraying

Requirement for selvedge is due to;• Being strength enough to withstanding the

strains during finishing process.• In order to have a neat and uniform appearance

so that all layers of fabric could be cut simultaneously and accurately

TYPES OF SELVEDGE FORMATIONS

• Hairpin selvedge – on shuttle weaving machine

• Leno selvedge with dummy selvedge• Helical selvedge• Tucked-in or tuck selvedge

TYPES OF SELVEDGE FORMATIONS

•A typical hairpin as shown in figure, selvedge which is formed when the weft package is carried in a reciprocating media, for example a shuttle.With most weaves it gives a good edge and requires no special mechanism

•Helical selvedges consist of a ste of threads which make a half or complete revolution around one another between picks.They can be used instead of leno selvedges and tend to have a neater appereance.

TYPES OF SELVEDGE FORMATIONS

Tucked- in selvedge gives a very neat and strong selvedge and was developed by Sulzer®. It’s appereance is closed to that of hairpin selvedge type and it is particularly useful when cloths with fringe selvedges would have to be hemmmed. Tucked-in selvedges, even when produced with a reduced number of warp threads, are generally slightly thicker than the body of the cloth.

Leno selvedge; In most shuttleless weaving machines a length of weft has to be cut for every pick. For looms not fitted with tucking motions the warp threads at the edges of the fabric have to be locked into position to prevent fraying.

LENO WEAVE PROPERTIES

•Leno weave has two warp thread systems: ground (basic) and skeleton ends (gauze). By means of two shaft systems - basic and skeleton-end - the skeleton-end threads are led alternately along the left- and right-hand sides of the group of basic threads.• Ground threads are threaded in the basic harness only; skeleton-end threads are fed into the shaft of the basic harness and to the half-healds of the skeleton-end harness, with the use of special steel wire healds and half-healds. •The skeleton-end threads are threaded under the ground and fed into the half-healds on the side opposite to that of the basic harness. •Depending on the wind, we distinguish between half-wound, whole-wound, one-and-a-half-times-wound, twice-wound, and two-and-a-half-times-wound gauzes.

LENO WEAVING

Leno weaving is particularly applied where open effect fabrics are in demand which, must have a solid structure between warp and weft threads. In order to achieve the weave a non-slip effect, two neighboring warp threads cross over each other.

LENO WEAVING

Leno healds offered by transall as shown in figure, depending on the nature of warp yarn to be woven or the desired opening of shed, Transally can offer suitable leno healds with lifting healds of synthetic material or stainless steel

PROBLEM OF LENO FABRİCS DETERMİNED BY SULZER®

• A characteristic feature of leno fabrics is that the warp ends do not run parallel but are twisted in pairs or groups between the individual picks.

• The crossing of weft and warp yarns is thus fixed and the fabric becomes slip-resistant. This type of interlacing is achieved using special leno harnesses with appropriate healds.

• Manipulating the harness with the leno healds, drawing in, and repairing of broken ends are very time-consuming.

• The yarn and especially also the leno healds are under such high strain that the performance of modern weaving machines cannot be fully exploited.

• Fabric production is correspondingly cost intensive.

SIMPLE WORKING PRINCIPLE OF THE TECHNOLOGY

• The simplicity and easy-to-understand function principle of the new system are shown in figure in catalogues.

• The leno thread turns through the openings in the guide bar and the stationary ends is drawn into an eyelet in the reed.

• Following weft insertion the guide bar moves upward and the eyeletted reed downward until the leno thread is over the eyelet of the stationary thread.

• Next, the guide bar is moved sideways until the leno thread is on the other side of the dent in the eyeletted reed.

• Then the guide bar moves downward and the reed upward, and the shed opens for the next weft insertion.

• As a result of these movements the leno thread comes to lie over the stationary thread. After insertion of the weft the motion squence is repeated in the opposite direction.

THE BENEFITS AT A GLANCE

• Productivity is increased thanks to higher machine rpm.

• PowerLeno leads to improved fabric quality • It is straightforward and easy to operate• There are fewer broken ends thanks to the low warp

strain.• The movements are much smaller than in

conventional leno harnesses.•   Powerleno is also available for large working widths.

THE BENEFITS AT A GLANCE

EasyLeno® 2T creates a new textile surface - the drebfabric

• EasyLeno® 2T is suitable to produce fabrics with various densities because no crimping capability is required in filling direction independent of the thread density.

• Temple cylinders with only two needle knurls are sufficient for fabric guidance in all density settings

Easyleno® 2t Advantages

• Innovative double-face fabric

• Reduced structural elongation (filling threads and carrier threads lay straight in the drebfabric)

• Higher density level and distinctly superior color brilliance

• Relief-type fabric surfaces through different yarn counts

• Variable density level settings allow mesh-like and compressed stripes

THANKS FOR YOUR PATIENCE