Introduction to Rapier Weaving
Among the modern picking mechanism rapier is a popular one. In this weaving machine a solid flexible or rigid element, called rapier, is used to insert the filling yarn across the shed whereas the rapier does not carry the weft package by itself.
Since 1972, the rapier weaving machine has evolved into a successful, versatile and flexible weaving machine. It is well known for its reliability and performance.
- A rapier performs a reciprocating motion.
- A wide range of fabrics (GSM 20-GSM 850) can be woven in this loom.
- Minimal stress is subjected to the weft yarn.
- Up to 16 different filling can be inserted.
- Low yarn breakage rate is achieved.
- Tappet, Dobby or jacquard shedding can be used with this picking mechanism.
- Modern loom has weft inserting rate of 1400m/min and 700picks/min.
- The noise level is higher than the jet loom.
- Here, production speed is less than the jet loom.
- The initial cost of the machine is more than the conventional loom.
- Type of Rapier.
- Number of Rapiers.
- Double or twin
- Method of weft insertion.
As the flexible double rapier looms are most usable loom and standard for the industry, the principle of that loom is discussed below which also facilitate the others principle
- Here two rapiers are mounted on two separate tape wheel which is outwards the opposite selvedges.
- The tape wheels get motion from the main shaft by means of motion transmission gear (Though there are many transmission systems).
- The motion is mechanically linked with the machine motion.
- The motion is completely under control, thus the position of the weft yarn at any instant during picking is exact.
- There are various attempts and alternatives to drive the rapier.
- Systems are still changing to obtain a smooth picking operation at high loom speeds.
- When the tape wheel gets motion both rapier starts to come towards the center of the sley.
- At the center of the sley, the giver rapiers transfer the pick to the taker rapier, as a result, complete pick insertion is done.
- This picking requires a precise sley dwell at the rear extreme position for the whole duration of the pick.
Overview of the Rapier Classification
According to the Method of Weft Insertion
|Weft insertion is done in the form of the hairpin in both rapiers.||Tip to tip weft insertion is done by both rapiers.|
|The weft yarn is not firmly gripped, only threaded around the rapier head.||The tip of the weft yarn is firmly gripped by the rapier heads during the entire period of weft insertion.|
|After collecting the weft from giver the taker retracts, as a result, the weft is straightened.||Type of weft transfer at the center.
Rapier picking system is one of the modern picking systems that is still running in the industries. The history of inventing this system is about 150 years old though the commercial use started in 1972.
All of these had some major disadvantages like wasted movement, taking large space, damaging the warp etc. and that’s why the standard loom is only discussed.
- HANDBOOK OF WEAVING by Sabit Adanur,2001; Page:273
- Rapier weaving by Emel Önder & Dr.Omer Berk Berkalp, May 17, 2006; Slide: 22