EP3377685B1 - Raschel warp knitting machine, netting and use of the warp knitting machine for making same - Google Patents

Description

BACKGROUND

The present invention relates to a Raschel machine, a net and the use of the Raschel machine for producing a net.

Nets are widely used as a material for air-permeable packaging of loose goods such as hay, straw, vegetables, raw cotton or other parts of plants. Networks can be produced, for example, by Raschel machines. Such Raschel machines are manufactured, for example, by the textile machine factory Karl Mayer GmbH, Frankfurt, Germany.

Raschel machines or networks are, for example, from the DE 196 38 392 A1 , DE 93 06 474 U1 , GB 2 124 975 A , WO 2012/119624 A1 , DE 69 36 578 U as WO 2012/160403 A1 famous.

SUMMARY

The present invention is based on the object of providing an improved Raschel machine as well as a net and an improved method for producing a net.

According to the present invention, the object is achieved by the subject matter and the method of the independent patent claims. Preferred further developments are set out in the dependent claims.

Those skilled in the art will recognize additional features and advantages after reading the following detailed description and viewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1

zeigt ein Beispiel einer Raschelmaschine mit einem hergestellten Netz.

Fig. 2A

zeigt ein Beispiel für einen ersten Nadelstab mit ersten Lochnadeln.

Fig. 2B

zeigt ein Beispiel für einen zweiten Nadelstab mit zweiten Lochnadeln.

Fig. 3

zeigt eine seitliche Ansicht einer Raschelmaschine.

Fig. 4

veranschaulicht ein Netz gemäß einem Ausführungsbeispiel.

Fig. 5

zeigt ein Netz gemäß einer weiteren Ausführungsform.

Fig. 6

zeigt eine Rolle mit aufgerolltem Netz.

Fig. 7

veranschaulicht ein Verfahren gemäß einer Ausführungsform.

The accompanying drawings are included to provide a deeper understanding of exemplary embodiments, they are incorporated in and part of this application. The drawings illustrate the main exemplary embodiments and, together with the description, serve to explain the principles the invention. Other embodiments and many of the intended advantages will be readily apparent upon a proper reading of the following detailed description. The elements of the drawings are not necessarily true to scale to each other. The same reference numerals indicate similar parts accordingly.

Fig. 1

shows an example of a Raschel machine with a fabricated mesh.

Figure 2A

shows an example of a first needle bar with first perforated needles.

Figure 2B

shows an example of a second needle bar with second perforated needles.

Fig. 3

Figure 10 shows a side view of a Raschel machine.

Fig. 4

illustrates a network according to an embodiment.

Fig. 5

Figure 3 shows a network according to a further embodiment.

Fig. 6

shows a roll with a rolled up net.

Fig. 7

illustrates a method according to an embodiment.

DETAILED DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part of the detailed description, and which show, for purposes of illustration, specific embodiments in which the invention may be practiced. In this context, directional terminology such as "top", "bottom", "front", "back", "front", "rear", and so on is used with regard to the orientation of the figures described in this context. Because the components of embodiments of the invention can be positioned in a variety of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It goes without saying that further exemplary embodiments can be used and structural or logical changes can be made without changing the scope defined by the patent claims.

The description of the exemplary embodiments is not restrictive. In particular, elements of the individual exemplary embodiments, which are described below, can be combined with elements from different exemplary embodiments.

For a more detailed explanation of the components of the Raschel machine or the network produced, the following terms are used in the following:
Mesh or fabric: thin tapes made, for example, of plastics, e.g. polyolefins such as LLDPE (linear low density polyethylene), LDPE (low density polyethylene), HDPE (high density polyethylene), PVC (polyvinyl chloride), EVA (ethylene vinyl acetate) ) or are made or consist of a similar plastic, are processed into a net or fabric.

Threads: The thin ribbons that make up the web.

Wales: The stitches that are strung together to form a loop in the direction of flow of the net.

Wefts: The threads with a zigzag interlacing that connect the warp threads to form a net.

MD (machine direction): The direction of flow of the net during manufacture or during unwinding.

TD (Transverse Direction): The direction perpendicular to the flow direction or machine direction.

Fig. 1 shows a schematic representation of components of a Raschel machine 100 as well as a network 200 produced by the Raschel machine. In this connection it should be noted that a Raschel machine usually contains a large number of further components which are omitted for reasons of illustration. In the following, those components are described in particular which are considered to be important for understanding the teaching according to the invention.

The Raschel machine 100 comprises a plurality of first perforated needles 110 for guiding warp threads 210. The first perforated needles 110 are arranged along a first direction. The first direction corresponds to the transverse direction, for example TD and is perpendicular to the direction of flow of the network. The number of perforated needles corresponds to the number of warp threads 210 to be produced. The Raschel machine furthermore contains a plurality of second perforated needles 150 arranged along the first direction for guiding weft threads 220. In addition, the Raschel machine comprises a plurality of needles 180 arranged along the first direction for production of interlocked stitches of threads, whereby the warp threads 210 are generated.

As in Figure 2A As shown, the first perforated needles 110 are held by a first needle bar 120. The second perforated needles 150 are held by a second needle bar 160. The second needle bar 160 is moved back and forth between two adjacent first perforated needles. The spacing between adjacent first punch needles 110 is greater than 25.4 mm (1 inch). Usually, the needles 180 are arranged on a metal base (sheets) (not shown), which performs a reciprocating movement of the needles 180 up and down. In this way, the threads are looped into chained stitches and wales are produced.

The first needle bar 120 with the first perforated needles 110 fastened therein can be designed as a metal base that moves in a circular manner. The position of the first piercing needles 110 is fixed along the transverse direction. The second needle bar 160, to which the second perforated needles 150 for guiding the weft threads are attached, moves back and forth along the transverse direction between two adjacent first perforated needles so that a zigzag pattern is formed when the warp threads move in the machine direction will. For example, a weft thread is guided between two adjacent warp threads 210 in such a way that it connects them to one another. This enables a knotless connection technology. At the connection points 215, the weft thread is passed through the loop from the warp thread 210.

The second needle bar 160, to which the second perforated needles 150 for guiding the weft threads are attached, moves periodically back and forth along the transverse direction by the distance d between adjacent first perforated needles. According to an illustrative example, it is now provided that the distance d between adjacent first perforated needles 110, for example in FIG Figure 2B is larger than 25.4 mm. For example, the distance d between adjacent perforated needles 110 can be greater than 28 mm, in particular greater than 30 mm. The distance d can be, for example, 30.48 mm (1.2 inches). According to a further example, the distance d can be even greater, for example 38.1 mm (1.5 inches), or more than 40 mm, especially more than 45 mm. According to the invention, the distance is 50.8 mm (2 inches). For example, the distance can be less than 101.6 mm (4 inches).

By using the Raschel machine according to the invention, it is now possible to produce a network with a greater distance between adjacent warp threads. The number of warp threads is correspondingly reduced while maintaining the same width. If, for example, 52 warp threads are required for a conventional net in order to produce a net with a standard width of 123 cm, nets with the standard width of 123 cm can now be produced with far fewer warp threads. As an advantage, a lower final weight of the net produced can be caused with the same strength of the threads used. Conversely, thicker threads than usual can be used, which simplifies production. The strength of the threads used can be adjusted so that the same final weight as with the conventional machine is achieved with a reduced number of warp threads. The fact that thicker threads are used reduces the risk of the threads breaking during manufacture. Accordingly, it is no longer necessary to interrupt production because the thread has broken. As a result, the throughput can be increased and the manufacturing cost can be reduced.

When dimensioning a suitable distance between adjacent perforated needles 110, it must be taken into account that, corresponding to the increased distance, the second needle bar 160 must move laterally by a distance that is also increased. If the frequency remains the same, an increased lateral movement path can lead to an excessive load on the drive motor for the second needle bar. Correspondingly, the frequency can be reduced in order to prevent overloading of the motor with an increased lateral movement distance. However, a reduction in the frequency again results in a slower production of the network and thus leads to a reduction in the efficiency of the Raschel machine. It has been found that when the spacing d between adjacent needles 110 is 50.8 mm (2 inches), optimum throughput can be obtained. For example, the frequency can be halved compared to a Raschel machine with a spacing of 25.4 mm (1 inch) between the needles 110. The advantages associated with the increased spacing of the warp threads of the finished net offset the disadvantages caused by halving the frequency. If the distance is greater, however, the efficiency of the Raschel machine is worsened due to the further reduced frequency. With a smaller distance, the weight saving can be achieved as a result of the compared to 25.4 mm increased distance may be too small to compensate for the disadvantages caused by an adaptation of the frequency.

The distance s between adjacent second perforated needles 150 on the second needle bar can correspond to the distance d between adjacent first perforated needles 110. Furthermore, the distance between adjacent needles 180 can correspond to the distance d.

Fig. 3 FIG. 10 shows a side view of the Raschel machine 100 with the generated mesh 200. Here, in particular, a side view of a single first punch needle 110 and a single second punch needle 150 is shown. As can be seen, the needle 180 for creating the interlocking loops is arranged so that it can perform an up and down movement. The first perforated needle 110 guides the warp threads for producing the wales, while the second perforated needle 150 guides the weft thread and moves back and forth between two adjacent first perforated needles.

As a result, as in Fig. 1 is shown, the wales 210 produced and the weft thread 220 passed through. The mesh 100 produced flows in the machine direction.

Fig. 4 shows a comparison between two generated meshes 200. Usually, Raschel machines are dimensioned in such a way that they enable a mesh to be produced with a predefined width. Standard widths generated by a Raschel machine are, for example, 123 cm. The first perforated needles 110 are usually arranged at a distance of 25.4 mm or shorter. This shows that in the upper part of Fig. 4 illustrated net 200, which has a total width v (for example 123 cm) and a distance t between adjacent warp threads 210 of 25.4 mm.

By using the Raschel machine according to the invention, a network 200 can now be produced with a greater spacing u between adjacent warp threads 210. The number of warp threads 210 is correspondingly reduced while the width remains the same. If, for example, 52 warp threads are required for a conventional net in order to produce a net with a standard width of 123 cm, nets with the standard width of 123 cm can now be produced with fewer warp threads 210. According to an illustrative example, with a spacing u of adjacent warp threads 210 of 30.48 mm (1.2 inches), nets of 42 warp threads can be made. With a spacing u between adjacent warp threads according to the invention of 50.8 mm (2 inches) the number of warp threads with the standard width of 123 cm is even less, for example about 26. As an advantage, a lower final weight of the net produced can be caused with the same thickness of the threads used. Conversely, thicker threads than usual can be used, which simplifies manufacture. The strength of the threads used can be adjusted so that the same final weight as with the conventional machine is achieved with a reduced number of warp threads. The fact that thicker threads are used reduces the risk of the threads breaking during manufacture. Accordingly, it is no longer necessary to interrupt production because the thread has broken. As a result, the throughput can be increased and the manufacturing cost can be reduced. The threads can have a thickness or strength greater than 90 μm or 100 μm .

Fig. 5 Figure 3 shows another embodiment of a network. Deviating from the in Fig. 4 The illustrated embodiment of the net are the point of entry 251 and point of ejection 252 of the weft thread into / out of the wale of warp thread offset from one another in the machine direction. For example, the weft thread 220 can only be guided along the TD direction again after a certain number of loops, for example three or four or more, in order to form the zigzag pattern. This can be achieved, for example, by appropriately controlling the movement of the second needle bar 160. For example, the second needle bar 160 can only move again along the transverse direction after a while. As a result, the weight of the net can be further saved and, ultimately, the strength of the thread can be increased while maintaining the same weight. The upper limit of the distance between adjacent first punch needles should be such that the net is not too wide-meshed so that the goods to be packaged do not fall out.

Fig. 6 shows an example of a rolled-up net.

Fig. 7 Figure 3 illustrates a method of making a mesh. As shown, the method comprises determining a lower limit for the thickness of a thread from which the warp threads are to be made (S100), determining a number of warp threads of the net (S110) so that the weight of the net with warp threads from the thread with the lower limit of the thickness does not fall below the weight of a standard net with a predetermined width, and determining a distance (S120) of the warp threads from the number of warp threads and the predetermined width. If necessary, the method can furthermore generate warp threads (S130) with the determined spacing and guide (S140) weft threads, respectively between two adjacent warp threads so that a zigzag pattern is formed.

For example, the lower limit for the thickness of the thread can be determined in such a way that it is ensured that the thread will not tear during the production of the net. For example, the lower limit for the thickness of the thread can be set to 90 μm or more. The thread can thus have a thickness of at least 90 μm or 100 μm . The predetermined weight of the net can correspond to the standard weight, for example 11 g / running meter (running meter). The predetermined width can correspond to the standard width of nets (e.g. 123 cm). For example, the number of warp threads can be less than 50, in particular less than 45, for example 42 or less. According to a further embodiment, the number of warp threads can be less than 35 or less than 30, for example 26 to 29.

Claims (9)

1. A Raschel machine (100), comprising:

   a plurality of first guide needles (110) arranged along a first direction for guiding warp threads (210);

   a plurality of second guide needles (150) arranged along the first direction for guiding weft threads (220);

   a plurality of needles (180) arranged along the first direction for creating interlocked loops formed by threads, whereby wales are created,

   wherein the first guide needles (110) are held by a first needle bar (120), the second guide needles (150) are held by a second needle bar (160) and the second needle bar (160) can be moved back and forth between in each case two adjacent first guide needles (110),

   characterized in that

   the distance (d) between adjacent first guide needles (110) is 50.8 mm.
2. The Raschel machine (100) according to claim 1, comprising a first and a second needle bar (120, 160).
3. The Raschel machine (100) according to claim 1 or 2, wherein the number of first guide needles (110) is less than 50.
4. The Raschel machine (100) according to any one of the preceding claims, wherein the second needle bar (160) can be moved back and forth by 50.8 mm in the transverse direction (TD).
5. A net (200) for packing hay, comprising:

   a plurality of warp threads (210) arranged along a first direction, and

   a plurality of weft threads (220), one of which runs in each case between two adjacent warp threads (210) and forms a zigzag pattern,

   characterized in that

   the distance (u) between adjacent warp threads (210) is 50.8 mm, and

   in that the threads from which the warp threads (210) are made have a thickness greater than 90 µm.
6. The net according to claim 5, wherein the threads are thin plastic bands.
7. The net (200) according to claim 5 or 6, wherein the number of warp threads (210) is less than 50.
8. The net (200) according to claim 7, wherein the number of warp threads (210) is less than 35.
9. Use of the Raschel machine according to any one of claims 1 to 5 for producing a net (200) for packing hay, straw, vegetables, raw cotton, or other plant parts.

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