This paper reviews the recent developments in rapier weaving and addresses the challenges that face the weaving industry. The paper sheds the light on how the weaving machine manufacturers and woven fabric producers might strengthen the weaving industry by further advanced the. Rapier Looms - Rapier Looms Weaving and Flexible Rapier ichwarmaorourbia.ga - Download as PDF File .pdf), Text File .txt) or read online. Detailed Project Report on Auto Loom/Rapier Loom (8 Nos.) Textile SME Cluster, Solapur, Maharashtra (India). New Delhi: Bureau of Energy Efficiency;.
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the outer rapier but, as the outer rapier is driven towards the center of the loom, the tape slides round the rollers so that the inner rapier. (Based on weft insertion system). Looms. Shuttle Looms. Shuttle-less Looms. Non-automatic Looms. Automatic Looms. Projectile Rapier Air-jet Water-jet. and weft) on a loom to form a woven fabric, it is actually a series of processes .. Figure Dobby mechanism (left) and Jacquard-controlled rapier loom (right).
Rigid and flexible rapier machines operate at speeds of up to 1, meters of weft per minute. These rapier looms are efficient. They operate at speeds ranging from about to 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 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 center, 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 center, 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.
They also weave yarns of any type of fiber and can weave fabrics up to inches in width without modification. The Projectile glides through the shed in a rake- shaped guide. Braked in the receiving unit, the Projectile is then conveyed to its original position by a transport device installed under the shed.
Patco exports is the leading Weaving Machine manufacturer and exporter. Rapier Weaving In Rapier weaving, a flexible or rigid solid element, called rapier, is used to insert the filling yarn across the shed. The rapier head picks up the filling yarn and carries it through the shed. After reaching the destination, the rapier head returns empty to pick up the next filling yarn, which completes the cycle. A rapier performs a reciprocating motion.
Rapier weaving machines can be of two types: 1.
Single Rapier Machines: A single, rigid rapier is used in these machines. The rigid rapier is a metal or composite bar usually with a circular cross section. The rapier enters the shed from one side, picks up the tip of the filling yarn on the other side and passes it across the loom width while retracting. For example, when a stiff heavy yarn is being processed, there may be mistransfers from the giver to the taker.
At yarn transfer the rapiers experience maximum acceleration in the outwards direction of movement because of the drive by the three-dimensional crank system; consequently, a maximum inertia force is effective in the weft yarn of the giver. After the reversal position this inertia force is directed oppositely to the direction of movement during the return of the giver, with the possibility that the weft yarn may slip out of the yarn clamp before being taken over by the taker and thus be unable to be transferred.
When endeavours are made to obviate this disadvantage by increasing the clamping force of the giver clamp, a new problem arises, for the yarn may then be damaged, for example, torn, when it is pulled out of the giver by the taker with a force which is bound to be increased because of the increased clamping force.
The problems described relate also to looms having rigid rapiers.
The invention therefor relates to such looms as well. SUMMARY OF THE INVENTION It is the object of the invention so to improve rapier looms of the kind hereinbefore set out, more particularly their picking mechanisms, that in particular the yarn transfer from the giver to the taker at the center of the shed is performed more reliably than previously, it being necessary for this working step to be adapted to the nature of the particular weft yarn used and to the clamping effect of the rapier clamps.
The invention solves this problem by driving the rapiers and yarn clamp openers with servomotors programmed to oscillate the rapiers at selected velocities and actuate the openers for selected intervals in accordance with the properties of the yarn.
Replacing the three-dimensional crank system for the tape wheel drive or rod drive by a servomotor provides further freedoms improving adaptation of rapier movements to the yarn takeover or yarn transfer conditions. Also, the special natures of the various yarns can be taken into account individually by means of programmed servomotors, the movement patterns of the rapiers being adapted to the particular weft yarn it is required to pick.
For example, the inertia forces at yarn transfer can be reduced without any reduction in loom speed. Also, in the event of a change in cloth width it becomes very simple to adapt the rapier strokes, such adaptation being effected by programmed adaptation of the control logic.
Further freedoms are obtained if the clamp openers according to the invention are disposed at the yarn transfer station at the center of the shed. The clamping force of the yarn clamp can then be set higher since automatic opening of the yarn clamp by the clamp opener prevents the weft yarn from being damaged at transfer. The use of clamp openers is known, for example, from DE-OS 3 However, in contrast to the known clamp openers the clamp opener according to the invention is driven in programmed manner by a servomotor.
One of the resulting advantages is that the clamp opener can be actuated individually--i. In some circumstances the clamp openers can be actuated just for some of the weft colors.
The two steps according to the invention, viz. The combination of the two features leads to a very advantageous picking mechanism.
Preferably high-dynamic servomotors are used as the servomotors of the rapier drives. A feature of such servomotors is that they can be used in a programmed manner like stepping motors; but they have much greater torques about Nm than stepping motors at typical rapier loom speeds of approximately min-1 and cloth widths of approximately 2 m.
These rapiers are illustrated in FIG. It will be apparent from the mirror image 1' of the giver 1 how the mirrored weft yarn 3' is retained by the wedge clamp, the same being embodied by two arms 11', 12', at a clamping station 31' or The arm 11' is resilient so that the yarn clamp can be opened by the pressure of an actuating lever 13' or 13 connected to the arm 11'.
Dobby Rapier Loom
The mirror 9 is of course disposed below the giver 1 purely for purposes of illustration. The giver 1 is moved by a flexible tape 4 mirror image 4'. At yarn takeover, the taker 2 is guided into the giver 1 far enough for a hooked tip 22 of the taker 2 to be able to engage the presented weft yarn 3 upon being drawn back arrow G. As shown in FIG.
Rapier Looms - Rapier Looms Weaving and Flexible Rapier Loom.pdf
The wedge clamp is opened outside the shed by the pressure of the lever 23 acting through the mechanism 24 for drawing the part 21 back.The combination of the two features leads to a very advantageous picking mechanism. If there is no velocity difference, then there would be no tension on the yarn results in curling and snarling of the yarn.
One end of a rapier, a rod or steel tape, carries the weft yarn. Also, in the event of a change in cloth width it becomes very simple to adapt the rapier strokes, such adaptation being effected by programmed adaptation of the control logic.
1.5 Kw Semi-Automatic 1.5kW Rapier Loom Machine
As in the projectile loom , a stationary package of yarn is used to supply the weft yarns in the rapier machine. For example, the inertia forces at yarn transfer can be reduced without any reduction in loom speed.
Claims 7 We claim: 1. The lever 61 is aligned parallel to the warp yarns of the shed not shown. After reaching the destination, the rapier head returns empty to pick up the next filling yarn, which completes the cycle.
Projectile Weaving Projectile weaving machines use a projectile equipped with a gripper to insert the filling yarn across the machine.