Weaving Machine Kazuhide Chikaoka and Ryuji Shintani* *Industrial Research Institute of Ishikawa, Kanazawa 1. Introduction The 6th OTEMAS was a very impressive show. In the weaving machine, 76 machines of 18 companies were exhibited as shown in Table 1. It was very interesting that companies of Korea and Indonesia exhibited first. Table 2 Fig. 1 The change of mean loom speed shows a comparison of the exhibits with the previous OTEMAS. From these tables, it is found that features of the 6th OTEMAS are as follows. 1) The number of exhibited looms decreased by 8, but the number of companies increased by 3. 2) The air jet loom (AJL) decreased by 15, and the companies also decreased by 4. 3) The flexible rapier loom (FRL) increased by 9, and the companies also increases by 4. 4) The rigid rapier looms (RRL) decreased. 5) The companies of Korea and Indonesia first exhibited water jet loom (WJL). 6) The multi-phase looms (ML) that were very impressive Reed Width cm in the ITMA '95 were exhibited. Fig. 2 Weft insertion rate of exhibited AJLs 2. Productivity Table 3 shows the maximum values of reed width, speed and weft insertion rate (WIR) in the OTEMAS. Figure 1 indicates the change of loom speed in the International Shows. It is clear that the productivity of all kinds of weaving machines remains on the same line or show a slowdown and there is no longer the speed race of weaving machine companies. In the wide width looms, the productivity is looking up. Figures 2 and 3 show the relationships between reed width and weft insertion rate in the AJLs and the FRLs. In both figures, the weft insertion rate of looms with a reed width xeea wiotn cm over 300 cm is equal to or larger than that with a normal width. This trend is remarkable in the AJL. The weft Fig. 3 Weft insertion rate of exhibited FRLs insertion rate of loom with a reed width of 390 cm is 3,120 m/min. This speed is larger than that in the 190 cm machine running at 1,600 rpm. To compare the productivity of weaving machines as mentioned above, the weft insertion rate that is the product of the machine speed and the reed width was generally used. The production coefficient recently proposed by A. Ormerod and W. Sondhelm [1], was defined by the weft insertion rate divided by the square root of reed width. It is found that the production coefficient in the AJLs as shown in Fig. 4 has a different trend from the WIR in Fig. 2. The Japanese companies exhibited AJLs and the nccu YY lu tll tall European companies exhibited RLs mainly in the last Fig. 4 Production coefficient of exhibited AJLs ITMA. It is clear that the European companies are good at developing various methods such as the cam, crank and the RL and are accumulating a lot of technology about RLs. screw types. In the cam type, the movement of rapier can For example, as to the drive mechanism of rapier, they was be freely designed by the change of the cam curve. The -35- Table 1 Details of exhibited weaving machines Table 2 The change in the numbers of waving machines and compaies in the OTEMAS Table 3 The change of the maximum values in the OTEMAS T4nm 1~4 Z r~ A41, ih crank type suits in the high speed machine because of a few parts and a simple structure. New FRLs developed by both companies of TSUDAKOMA and TOYODA were extremely remarkable before the show was hold. These looms use a crank type for the drive mechanism of rapier and the productivity may be almost the same as the European's. It is one of the features that a rapier guide doesn't be needed owing to be stable movement of the rapier with improvements of shape and material. However, the total evaluation of these FRLs starts from now. New developed FRLs were also demonstrated by European companies such as PICANOL and VAMATEX. Moreover, SSANGYONG exhibited a FRL with 800 rpm. It seems that the loom makers in the advanced countries need to pay attention to low cost looms made in Asian countries in the future if their productivity and durability are improved. In the highly productive looms, M8300 of SULZER RUTI was first exhibited in Japan (cf. Fig. 5). This is a multi-phase loom of the air jet use which was first shown in Fig. 5 M8300 multi-phase loom the ITMA'95 and gathered a topic most. And this loom -36- has the WIR of 5,000 m/min which is about twice as fast as different kinds of weft yarns with WJLs with two pumps AJL's because the four picks are filled at the same time. and the positive Dobby of upper side type. In the ITMA'95, only cotton plain fabrics were woven, but this time, fabrics which used filament yarns for warps were 4. Automation System also woven and the loom was running better than the time of the ITMA. Moreover, its noise was 10 dB lower than The automation systems which are the Automatic Pick normal AJL's because of the continuaous sound like circular Remover, the Automatic Setting of Weaving Condition knitting machines. And the power consumption decreased System, the Stop Mark Prevent System and so on, became a by 30 % by the use of a low air pressure for the weft topic in the last OTEMAS. However, they are no longer insertion. This ML is just an innovative loom today, and it special accessories. The noticeable systems in this needs to be noticed in the future because it will be account OTEMAS are explained below. for the constant share in the regular fabrics of mass production. 4.1 The Quick Style Change System (QSC) 3. Flexibility The QSC which decreases a waste time of work changes was the first topic in the last OTEMAS. Six companies The main theme of the 6th OTEMAS was to be all rounds demonstrated that the work change was carried out with 30 and each company was weaving various kinds of fabrics. min. The rare scenery that visitors clapped their hands Tables 4 and 5 are the details of woven fabrics by the AJL was seen when a demonstration was over. In the present and RL in the present and last OTEMAS. By comparison OTEMAS, however, it seemed that the development of of these tables the features in the 6th OTEMAS are as QSC stopped because only TOYODA demonstrated. A follows. large-scale automation system could not be easily 1) The composite fabrics which used different kind for warp introduced to a weaving factory when considering a profit. and weft yarns were woven with AJLs and RLs, instead However, continuous development of the system that of the sheet or the high count cotton fabric made with matches with large variety and small lot production is AJL. This reflects the boom of the composite fibers and expected in existing looms and factories. the composite fabrics in these years. 2) Moreover, it was one of the features that the recently 4.2 Fabric Inspection on the Loom booming stretch fabric which used the spandex for well yarns was woven with AJL and RL. Especially, A Fabric Inspection System was first exhibited on weaving spandex with AJL is the first try. In order to TOYODA AJL which wove denim. This system can suppress the weft stack, this was equipped with a inspect warp faults such as mistakes of the reed threading, cramper to hold a weft yarn at the main nozzle entrance the design, the yarn count and so on by moving a sensor and a yarn catcher to hold positively its weft end on the installed between a cross point and a breast beam. The opposite side of the main nozzle. development of automatic fabric inspection machines had 3) The weaving of denim and synthetic fabrics with highly done in every direction but were not enough in performance twisted yarns shifted to AJL. and cost. Therefore, if the fabric inspection system can be 4) Towel and synthetic fabrics are still woven with both of used like the yarn sensor, it is expected to improve the AJL and RL. fabric quality. In addition, if the fabric inspection process 5) However, the weaving of fabrics for interior and of becomes unnecessary, it is able to decrease sharply in the woolen fabrics are shifting to RL. production cost and to popularize this system. On the other hand, Table 6 shows the number of shedding 5. Resources Saving, Energy Saving and machines. The percentage of the Dobby and Jacquard in Environment Measures AJL increase to extend the flexibility and reaches 46 %. However, in case of RL, it reaches 97 % and is larger than The energy consumption increases with productivity in AJL's. weaving machines. Especially, the power consumption of The difference of the fabrics woven with AJL and RL has AJL is bigger than the other weft insertion systems. A become much unclear because the flexibility of AJL has technician in a waving machine company was talking as extended and approached that of RL. Therefore, the RL follows. The power consumption of AJL was reduced by was weaving such complicated fabrics as interior and 20 to 30 % owing to the improvement of the nozzle shape, woolen fabrics which used nap yarn for warps, and weak, the jet direction, the response of the magnetic valve and so thick or knotted yarn for wefts. on. However, there is no good idea to inform of this fact.