Rapier Weaving Machine || Rapier Pick insertion principle || Features of Rapier Loom || Advantages of Rapier Loom

Rapier Weaving Machine || Rapier Pick insertion principle || Features of Rapier Loom || Advantages of Rapier Loom

Rapier Weaving Machine:

Rapier loom is a shuttle less weaving loom in which the filling yarn is carried through the shed of warp yarns to the other side of the loom by sword like carriers called ‘Rapiers’. As in the projectile loom, a stationary package of yarn is used to supply the weft yarns in the rapier machine. One end of a rapier, a rod or steel tape, carries the weft yarn. The other end of the rapier is connected to the control system .The rapier moves across the width of the fabric, carrying the weft yarn across through the shed to the opposite side. The rapier is then retracted, leaving the new filling in place.
Rapier Weaving Machine
Image source - Google | Image By - Textile learner



In some versions of the machine, two rapiers are used, each half the width of the fabric in size. One rapier carries the yarn to the centre of the shed, where the opposing rapier picks up the yarn and carries it the remainder of the way across the shed. A disadvantage of both these techniques is the space required for the machine if a rigid rapier is used. The housing for the rapiers must take up as much space as the width of the machine. To overcome this problem, looms with flexible rapiers have been devised. The flexible rapier can be coiled as it is withdrawn from shed and therefore requires less space. However, if the rapier is too stiff, it will not coil; if it is too flexible, it will buckle. The double rapier is used more frequently than the single rapier. Rigid and flexible rapier machines operate at speeds of up to 1,300 meters of weft per minute. These rapier looms are efficient. They operate at speeds ranging from about 200 to 260 ppm at about the noise level of projectile looms. They can produce a wide variety of fabrics ranging from muslin to drapery and upholstery materials.


The operation principle of three rapier systems
Image source - Google | Image By - Textile learner


Newer rapier machines are built with two distinct weaving areas for two separate fabrics. On such machines, one rapier picks up the yarn from the centre, between the two fabrics, and carries it across one weaving area; as it finishes laying that pick, the opposite end of the rapier picks up another yarn from the centre, and the rapier moves in the other direction to lay a pick for the second weaving area, on the other half of the machine. The above figure shows the action on a single width of fabric for a single rigid rapier system, a double rigid rapier system, and a double flexible rapier system. Rapier machines weave more rapidly than most shuttle machines but more slowly than most projectile machines. An important advantage of rapier machines is their flexibility, which perm it’s the laying of picks of different colours. They also weave yarns of any type of fibre and can weave fabrics up to 110 inches in width without modification.





Rapier Pick insertion principle can be of two types:

1. Dewas system : It is a tip of yarn transfer principle. The tip of weft yarn is firmly gripped by the rapier heads during the entire pick insertion. Tip of weft transfer takes place at the centre of reed space. The giver grips the tip of the yarn, brings it to the centre and transfer it to the taker which retracts and carries the yarn to the other side of the weaving machine.

2. Gabler system: It is a loop transfer system. weft insertion takes place in the form of Hairpin. Weft yarn is not firmly gripped, merely threaded round the rapier head. After its transfer at the centre, it is straightened as the taker retracts the shed. The giver extends the yarn in the form of ‘U’(loop) to the centre of weaving machine. The yarn is transferred to the taker, which extends the yarn to the other side by straightening it.

Features of Rapier Loom:

1. A useful feature of rigid rapiers is that they can be simultaneously inserted in two sheds one above the other, for producing double plush and certain carpets.
2. Rapier loom may have various types according to the weft insertion mechanism & number of pick such as insertion of double pick, insertion of single pick, two phase rapier etc.
3. In all rapier looms to-and-fro-movement of the rapiers is derived initially either from a linkage mechanism or from a cam. The use of linkage mechanism has the advantages of simplicity reliability & is cheap, quite and consumers less energy than a cam mechanism but it does not provide any dwell to the rapiers.
4. The only two phase rapier in commercial operation is the saurer of width 2 x 185 cm or 2 x 220 cm having weft insertion rate is about 1200 mpm.
5. The rigid rapier is driven from the centre and has a rapier head at each end.In one cycle of 360 degree the rapier inserts one pick alternately in the right hand and the left hand fabrics, the picks being inserted and beaten up in opposite phase .
6. In gabler system of weft insertion the rapier system is combined with air jet picking system.
7. Gabler system rapier may be single sided or double sided. The machine include on gabler system Draper DSL,Gusken etc.Those operating on dewas system include dornier, picanol, Novo pignon, Sommet, Sulzer-Ruti etc.


Features of Rapier Loom:

Control panel:
The loom is controlled by the control panel with a micro-computer, the LCD display provides a very user-friendly human-machine interface, which shows the production statistic data of each shift and provides the weft colour programming function.

Weft color selection:
The machine adopts electronic color selector up to 8 colours, and the colour selection pattern is programmed directly on the machine control panel.

Wefting:
Wefting mechanism adopts 6-lever wefting structure and can ensure the adjustment of the rapier entry and exit time and ensure stable wefting and insertion motion. This machine adopts 4 levers, short connectors and short sley to complete the beating motion, the rock shaft adopts 110mm (diameter)

Control panel:
The loom is controlled by the control panel with a micro-computer, the LCD display provides a very user-friendly human-machine interface, which shows the production statistic data of each shift and provides the weft colour programming function.

Weft color selection:
The machine adopts electronic color selector up to 8 colours, and the colour selection pattern is programmed directly on the machine control panel.

Wefting:
Wefting mechanism adopts 6-lever wefting structure and can ensure the adjustment of the rapier entry and exit time and ensure stable wefting and insertion motion. This machine adopts 4 levers, short connectors and short sley to complete the beating motion, the rock shaft adopts 110mm (diameter) seamless tube to ensure the beating strength and can be suitable for high-speed motion and weaving of heavy and high density fabrics. The rapier transmission box adopts the advanced helix umbrella gears to ensure stable transmission. The tension device adopts 3-rear-beam tension structure, which is specially designed for balancing the warp tension of high-density weaving and can improve the quality of the weaving fabrics.

Pick finding mechanism:
The machine adopts electronic let-off mechanism with a high-accuracy step motor and the optimized mechanical take-up system for stable and accurate pick finding motion. The pick finding motion is very stable and proved to be very successful and reliable. The adoption of two pressing rollers on the fabric winding roller enables the worker to unload the fabric from the fabric roller without stop. The frequent adoption of bearings for the major moving parts provides better performance and easier maintenance.

Advantages of Rapier Loom Over Conventional Loom:

1. The rapier loom doesn’t require dynamic forces or anything like the magnitude as those involved in the conventional loom.
2. The weft insertion rate in a rapier loom is very much influenced by the method of weft control.
3. Weft insertion rate is very high rather than any conventional loom
4. It can occur double pick at a time by double picking insertion system. Here is no need to cut the weft selvedges and no weft wastage.
5. Weft insertion rate is very high rather than any conventional loom Rigid rapiers has a useful features that they can be simultaneously inserted in two sheds one above the other ,for producing double plush and certain carpets.
6. Looms that use rigid rapiers eliminate entirely the need to assist the rapier head through the warp shed, this is an undoubted advantage.








Rapier Weaving Machine || Rapier Pick insertion principle || Features of Rapier Loom || Advantages of Rapier Loom Rapier Weaving Machine || Rapier Pick insertion principle || Features of Rapier Loom || Advantages of Rapier Loom Reviewed by Suraj Gupta on May 09, 2020 Rating: 5

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