Projectile weaving machines
These machines are mainly used for spun yarns made of cotton, rayon, polyester, etc and also their blends. It is also possible to effectively weave filament yarns. The technical aspects relating to warp yarns remain the same irrespective of whether it is shuttleless or shuttle looms. Some of the recommended weft yarn counts are given in Table1 below.
These machines can satisfactorily weave sheeting, flannels, drills, muslins, print cloths, etc and it can be extended to the weaving of carpets from continuous filament yarns. Textured filaments made from Taslan, untwisted filament and intermingled cotton and polyester covered core yarns and elastomeric yarns can be effectively woven on these machines. Heavy denier multifilament yarns can also be successfully used. PET with crepe twist or reinforced Lurex is both woven as weft without problems. Industrial fabrics, tyrecords, tents, screens, sailcloth tarpaulin, and glass fabric can also be woven
Air-jet weaving machine
These machines have proved to be ideal for spun yarns. Recently it has been possible to weave a wider range of fabrics in spun as well as filament yarns and with up to six colours in weft or yarn counts. However, the yarn quality restricts the machine speed. Modem spinning mills are able to give better quality yarns. Modem warp preparation is crucial for today’s weaving machines.
Water-jet weaving machine
This system has proved very useful in the case of synthetic filament yarns, which are hydrophobic. It is advantageous as compared with shuttle looms for bulk production of fabrics made of polyamides and other hydrophobic fibres. This machine is confined to only hydrophobic synthetic filament yarns. This is due to the problems associated with sizing, the wet strength of hydrophilic yarns and also the requirement of a perfectly clear warp shed. Thus the machine is restricted to filament warp yarns that do not require sizing and also do not lose strength on wetting.
Normally weaves such as crepe, matt, and twill are used, with yarn counts ranging between 10 – 120 denier. The warp/weft thread sett or density ranges between 25/25 and 360/240 per square inch and the maximum achievable areal density of the fabric is about 6 0zlsq yd. Since the construction of the weaving machine, especially, the sley is light, heavier varieties of fabrics cannot be woven. There is a possibility to increase the weft set to 300 picks/inch.
However, the maximum dents/inch in reed is only 76. If reeds of higher densities are used, there is a problem of water clogging, which can create difficulties in shedding. The twist in warp yarns is minimum, about 7.5 TPI, as the yarn is unsized. Fabrics such as lingerie, ladies dresses, shirting, tent canvas and industrial fabrics can be successfully woven on these machines. The overall quality of the fabric is below the expected level, which is mainly due to the problems concerned with the water jet weft insertion.
These machines have the advantages of high speed and low noise. Also, they are well suited for weaving superfine continuous filament yarns. The effectiveness of the weft propulsion is mainly dependent on the wettability of the weft. The drag on hydrophobic filament yarn is much lesser than that on cotton yarns. Generation of static charges is prevented due to the presence of water. It is crucial that the weft yarns do not contact the warp yarns during their insertion into the shed, as otherwise, this could lead to fabric defects due to entanglement.
The effectiveness of weft insertion requires the fluid jet to remain in contact with the weft and to move into the shed more quickly than the yarn. A major problem with hydraulic picking is the presence of partial full double picks across the width of the fabric, which can arise due to a number of reasons.
Weaving with multifilament yarns
Multifilament yarns are used in the manufacture of apparel so as to get an excellent hand, drape, appearance, wrinkle resistance and easy-care properties. The yarns are either used as single or plied together with or without twists. The yarns are denoted as denier/number of constituent filaments/twist. Generally higher the number of filaments of equal denier, fuller is the fabric. The yarns can be woven successfully on any of the following types of machines (Table 2) but certain modifications on looms are required for satisfactory weaving. It is desirable to weave the filament warp beams on better and sophisticated looms.
|Type of weaving machine||Products|
|Projectile/Rapier||• Fancy multicolor fabrics coarser than 30 dTex, both flat and texturized
• High twisted fabrics
|Air-jet||• Fabric with single color weft for mass production|
|High speed automatic shuttle looms, conventional automatic looms||• Fancy monocular fabrics
• High twist fabrics
|Non-automatic looms||• All type of synthetic fabrics|
Recommended Warp Count
|Warp count dTex||Cross-section of Heald mm x mm||Sizes of eyes mm x mm||Maximum Simplex||Heald wire per cm Duplex|
|Upto 150||1.0 x 0.25||5.0 x 1.0||16||24|
|140 to 300||2.0 x 3.0||5.5 x 1.2||12||20|
Tarpaulin Fabric : 280g-800g/sqm, PVC tarpaulin, 200D*300D,250D,500D(18*17) 1000D(20*20), truck cover,awning,tent,etc
See the first part of this article here.
This study was conducted to identify the relationships between increase in market share through product development and innovation. Many studies have been done on the concept of product development and innovation and much of what has been written tends to discuss this concept as a veritable tool for improving the life cycle of a product without substantial relation to market share enhancement.
The invention provides a manufacture method of water-proof sailcloth, which solves the problems of the prior art that manual work cost and management cost are added by large area occupied by creels. From the survey it can be concluded that there is huge demand of vinyl tarpaulins in local and international market. Companies can enter in to the market with best features, best pricing policy and best promotion tools.