Loom

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A weaving machine is a machine on which several thread systems are crossed with each other at right angles and run over and under each other so that a fabric is created. The thread systems are called warp and weft.

The term loom is often used for the loom , both in colloquial language and in specialist literature.

Textile fabrics in widths of 90 to approx. 500 cm are being produced on almost 10 million looms worldwide at the beginning of the 21st century. This includes more than 5 million mechanical looms (4 million shuttle and about 1.2 million shuttleless machines) and around 4.6 million hand looms. There are also several thousand ribbon, hose and metal wire looms in operation.

History of the loom

The first looms were the so-called belt mills, which were used to produce belts in the 16th century. The oldest design of a mechanical loom dates from 1678, but was never implemented.

In 1728 a silk weaver from Lyon used perforated wooden boards to control his looms. Jacques de Vaucanson from Grenoble further developed this simple loom into a model mechanically controlled by a wooden punch card (1745). With this machine it was possible for the first time to produce patterned fabrics. However, the device never got beyond the status of a prototype and was never used industrially. Almost at the same time, namely in 1733, John Kay invented the rapid shuttle, which doubled the weaving speed.

If these looms were still being operated by hand, Vaucanson found a way that they could be operated with a gopel through a horse or a donkey. The pattern was created by a cam roller .

Pastor Edmund Cartwright patented a fully mechanized loom, the Power Loom, in which the three different basic movements of weaving, namely raising or lowering the shafts, inserting the weft with throwing the shuttle through the shed and hitting the ark, are all in one Drive was transferred. This loom was known as the Power Loom . On April 4, 1785, Edmund Cartwright received British Patent No. 1470 "Machine for weaving [by power]". In the following three years further patents (1786 No. 1565, 1787 No. 1616 and 1988 No. 1675) were added, which served to improve this loom, which was registered in the basic patent (e.g. device for mechanically stopping the machine for warp or Weft breaks, regulating the warp and the fabric tree as well as a mechanical shooter change). After the looms in his factory, founded in 1786, were still driven by a gopel, he installed a steam engine as a drive unit as early as 1788.

This technology destroyed a great many jobs. As a result, there was a machine storm and many looms were destroyed. In particular, the Elberfeld weaver revolt of 1783 and the Silesian weaver revolt of 1844 illustrated the social misery in the declining family trade.

The invention of a shedding device by Joseph-Marie Jacquard , which was named after him, the jacquard machine , was decisive for a significant increase in performance in the production of patterned fabrics and the saving of labor . In doing so, Jacquard leaned on a pattern technique developed by Vaucanson, but achieved an incontestable originality by changing and enriching the technique. Upon his return to Lyon in 1804, Jacquard worked on his new technical training technique and in 1805 made his main invention, the jacquard machine. This jacquard machine finally reached its perfection in 1808 and thus found rapid distribution, so that as early as 1812 in France 18,000 looms were equipped with it. This allowed the warp threads in the weaving machine to be lifted as desired by the jacquard machine installed above, according to the pattern.

These punch card looms were not only one of the most important contributions to industrialization, but also the cornerstone for the development of control technology up to and including modern computers. Desired patterns in the fabric were stored on a punch card and mechanically scanned. Today, of course, the jacquard machines are controlled fully electronically.

The first steam-powered loom was used in Bradford in central England towards the end of the 18th century.

It was not least the invention of the weaving machine that sparked the fear of David Ricardo , Friedrich Engels and Karl Marx that technical progress would in the long run lead to mass unemployment.

There were two effects:

  • the productivity of a worker increased many times over
  • the cost of the web product dropped significantly.

In addition to the spinning machine , the invention of the weaving machine was one of the most important milestones of the industrial revolution . They changed the production conditions decisively and former homeworkers had to make a living as factory workers.

The further development of the insertion of the weft thread went via the rapier weaving machine to the current air jet weaving machine .

However, weaving machines not only changed the social reality of people, but also the products themselves: the handicraft design was replaced by technically perfect patterns. Exclusive luxury items became bourgeois consumer goods and mass-produced goods.

Structure and functionality of a simple weaving machine

Principle of a loom with two shafts
Principle of a weaving machine with two shafts in a three-dimensional view.
The warp threads are unwound from the warp beam . The up and down movement of the shafts creates a spreading between adjacent warp threads. The weft thread is shot into this compartment with the shooter . The finished fabric is rolled up onto the goods tree.

The warp threads required for the production of the fabric are wound in parallel under tension on the warp beam . The warp beam is used to supply the warp thread as required.

The warp threads are on the back beam deflected into the Web tier. The backrest is usually spring-loaded in order to compensate for the warp thread tension during shedding, which is necessary for a uniform fabric quality. It also serves as a sensor for the warp release device. This controls the speed at which the warp threads are unwound (warp let-off speed).

The warp threads are passed through the eyes of the strands that are attached to the top and bottom of the shafts . In a simple weaving machine with two shafts, one shaft is always raised while the other shaft is lowered at the same time, then the same in the opposite direction. Step mechanisms or dobby machines are used as mechanisms for shaft movement.

With the shafts, the strands suspended in them and the warp threads are moved at the same time. Those strands are grouped together on a shaft, the warp threads of which have the same course in the fabric according to the pattern repeat . In the simplest case, two adjacent warp threads always move against each other: When one warp thread is raised, the next warp thread is lowered at the same time. So in the chain (all of the warp yarns) formed a specialist . The shooter is led through the shed to insert a weft thread at right angles to the warp threads (illustrative video: see).

The weft thread density (weft density) of the fabric results from the speed at which the warp threads are transported and the number of weft threads that are inserted per unit of time . This indicates how many weft threads are in a fabric at a certain reference length.

The warp threads are passed on through the reed which is integrated into the sley. The warp threads are arranged by the reed. The warp thread density is also set here. The warp thread density is usually given as the number of warp threads per cm of fabric width.

When weft insertion, the reed is at the rear dead center with the shed open. During the shed change, the sley moves with the reed towards the tree . The reed strikes the last inserted weft thread against the fabric edge, then it returns to the starting position. The finished fabric is deflected on the breast tree and wound onto the tree.

Classification of weaving machines

According to specialist training institutions

  • On machines for simpler weaving, the shaft movement (maximum 14 shafts) can be emphasized by an eccentric drive. The weft repeat length is limited to 8 wefts.
  • Weaving devices with dobby machines can be used with max. 32 stocks can be occupied, the practical limit for the Rappot length is given as 5000 shots.
  • In shedding with jacquard machines, individual warp threads are passed through strands, the movement of which is controlled individually, in modern systems electronically. The warp repeat length is unlimited; in practice, a maximum repeat length of 5000 is calculated for the weft.

Classification of weaving machines

According to weft insertion devices

Single-phase looms

In single-phase looms, a weft is inserted over the full width of the warp in a single phase of the machine's work cycle.

  • Shuttle loom : With each machine revolution, a shuttle passes through the shed, a yarn spool is inserted in the shuttle from which the weft yarn is unwound. With this system, a maximum of approx. 400 m wefts can be woven per minute.
  • Projectile loom : weft yarn is transported by means of a projectile, which is brought back to the starting position on a conveyor belt after passing through the shed. These machines achieve a weft insertion of up to 1570 m / min.
  • Rapier weaving machine: Weft yarn is cut according to the width of the fabric and inserted into the shed using one or two needles. Machines of this design were first produced in 1930, the maximum output (2016) is 1620 meters weft penetrations per minute.
  • Jet looms
    • Air jet weaving machine: weft insertion is carried out by an air stream (approx. 0.7 MPa). The first machines of this type were manufactured in 1951, and in 2016 air jet machines achieved an entry rate of up to 2500 m / min.
    • Water jet loom : A water jet pumped into the shed enables weft insertion. The machine can only be used for synthetic fiber threads. Maximum weft insertion approx. 2400 m / min.

Multiphase looms

In multi-phase looms, several weft threads are inserted at the same time. Several phases of the loom's work cycle therefore take place at the same time.

  • Wave shedding machine contains several sections of heald frames that move in waves next to each other. In the 1980s and 1990s, some prototypes of this machine were made with the maximum shooting performance up to 3000 m / min. tested, nothing is known of a series production until 2016.
  • Rotating multi-phase loom basically consists of 12 complete sheds that are attached to the circumference of a drum in such a way that weft threads can run through 4 sheds at the same time. Small series of rotating machines have been tested in practical operating conditions for several years, the maximum output reached up to 6000 meters weft insertion per minute. Since a profitable series production was not possible, the further development was stopped in 2005.
  • Circular looms contain several sections of heald frames that are distributed in a circle. Up to 10 weft yarn carriers run around in this circle, the heald frames form an open compartment, depending on the position of the individual yarn carriers, through which the weft thread is pulled. The weft yarn carriers rotate up to 120 times per minute, during which a maximum of 1200 m of weft yarn can be woven. Machines are built with a diameter of up to approx. 500 cm. Use: Almost exclusively for packaging material made of polypropylene tapes.

According to the weaving width, type and equipment with special devices

According to the weaving width, flat weaving machines are divided into wide weaving machines and ribbon weaving machines. The wide weaving machines include weaving machines with a maximum reed width greater than 30 cm, weaving machines with a fabric production width between 90 and 500 cm are usually used. But there are also special weaving machines z. B. for the production of wet felt base fabric with a reed width of up to 35 m. Flat weaving machines with weaving widths of less than or equal to 35 cm are counted as ribbon looms.

Both wide and ribbon looms are designed in light and heavy designs. The heavy-duty weaving machines are designed to be larger and more stable, which applies in particular to the sley and the backrest. This means that fabrics can be produced in which the dynamic warp tensile force is above 3000 N.

Special devices are available on certain weaving machines or are attached as special mechanisms. In this way, special structures of the fabric or pattern effects can be achieved or metal wire can be processed. The wide weaving machines with special devices include, for example, terry cloth weaving machines, rod pile weaving machines, rapier Axminster weaving machines and felt cloth weaving machines. Ribbon looms with special devices are z. B. multi-course ribbon looms with several weft insertion needles per course and ribbon looms for the production of endlessly woven drive belts.

Examples of the structure and mode of operation of looms with special devices are given in the following sources.

Individual evidence

  1. ↑ Fabia Denninger (Ed.): Lexicon of technical textiles . Deutscher Fachverlag, Frankfurt am Main 2009, ISBN 978-3-86641-093-0 , p. 471.
  2. ↑ a b Indian power loom industry: an overview fiber2fashion.com (Indian online magazine), 2016.
  3. ↑ Tops & Flops in Textile Machinery Lecture by the Swiss company Gherzi on statistics (as of 2008)
  4. ^ Range of ribbon looms from Jakob Müller AG
  5. ↑ Starlinger circular looms
  6. ↑ Wire weaving machines for fabrics schlatter.ch
  7. ^ A b Stefan Mecheels, Herbert Vogler, Josef Kurz: Culture and industrial history of textiles . Wachter, Bönnigheim 2009, ISBN 978-3-9812485-3-1 , p. 306.
  8. ↑ Bennet Woodcroft: Subject-Matter Index (Made from Titles only) of Patents of Invention, From March 2, 1617 (14. James I.), to October 1, 1852 (16 Victorie), Part II. (N - Z) . The Great Seal Patent Office, London 1857, pp. 913 f.
  9. ^ Paul-August Koch, Günther Satlow: Large Textile Lexicon: Specialized lexicon for the entire textile industry. Volume: A – K. Deutsche Verlags-Anstalt, Stuttgart 1965, p. 631.
  10. ^ Karl Karmasch: History of technology since the middle of the eighteenth century. Verlag R. Oldenbourg, Munich 1872, p. 682.
  11. ↑ An Illustrated History of Computers, Part 2 , accessed November 1, 2016.
  12. ↑ a b Chokri Cherif (Hrsg.): Textile materials for lightweight construction - Techniques - Processes - Materials - Properties. Springer-Verlag, Berlin / Heidelberg 2011, ISBN 978-3-642-17991-4 , p. 187.
  13. ^ A b Thomas Gries, Dieter Veit, Burkhardt Wulfhorst: Textile manufacturing processes - An introduction. 2nd, revised and expanded edition. Carl Hanser Verlag, Munich 2014, ISBN 978-3-446-44057-9 , p. 152.
  14. ↑ How does a loom work? Video with a clear explanation, created in the LVR-Industriemuseum Euskirchen ( cloth factory Müller ).
  15. ↑ Fabia Denninger, Elke Giese: Textile and Model Lexicon. Band: LZ. 8th, completely revised and expanded edition. Deutscher Fachverlag, Frankfurt am Main 2006, ISBN 3-87150-848-9 , p. 640.
  16. ↑ Fabia Denninger, Elke Giese: Textile and Model Lexicon. Volume: A – K. 8th, completely revised and expanded edition. Deutscher Fachverlag, Frankfurt am Main 2006, ISBN 3-87150-848-9 , p. 364.
  17. ↑ International Standard ISO 5247-1
  18. ↑ History of Weaving Classification of Weaving Machinery Online learning materials from Prof. Dr. E. Önder (PDF)
  19. ↑ a b DIN ISO 5247-1: Textile machines and accessories - Weaving machines - Classification and terms. May 2005, p. 4 f.
  20. ↑ Comparison of shuttle and shuttleless looms Comparison of the weft insertion rate in m / min with different looms (as of 2009)
  21. ↑ Video: A semi-automatic shuttle loom in operation
  22. ↑ Example for a projectile machine (PDF), 2016.
  23. ↑ Subhankar Maity et al .: Recent Developments in Rapier Weaving Machines in Textiles Americal Journal of System Science, 2012.
  24. ↑ Example of an air jet machine ( Memento of the original from July 27, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF), 2016. @1@ 2Template: Webachiv / IABot / www.lindauerdornier.com
  25. ↑ Video: An air jet loom in operation
  26. ↑ Example of a water jet machine , 2016.
  27. ↑ Video: A production hall with water jet looms
  28. ↑ Video: How a wave shed loom works
  29. ^ Developmemts in Weaving specialist article on scribd.com, 2010.
  30. ↑ Video: How a rotating multi-phase loom works
  31. ↑ Tops & Flops in Textile Machinery Lecture by the Gherzi company (2010), see Section 3: The multi-phase loom : An example of product development
  32. ↑ Video: A circular loom in operation
  33. ↑ Video: A production hall with circular looms
  34. ^ A b c Heinz Hollstein, Hanskarl Hahn, Rolf Meixner: Manufacturing technology weaving. Volume 3: The weaving machines and their use for fabric production . Fachbuchverlag Leipzig, 1988, ISBN 3-343-00399-9 , pp. 15-17.
  35. ↑ Video: Terrycloth looms in operation
  36. ↑ Video: How a double plush weaving machine works
  37. ^ Looms for Axminster carpets
  38. ↑ Brochure about lattice weaving machines (PDF), schlatter.ch
  39. ↑ Brochure about wire weaving machines (PDF), schlatter.ch