EP3412817A1 - Node-less fish farming grid - Google Patents

Abstract

A knotless Fischzuchtgitter (10) has a longitudinal grid webs (6) and transverse to extending transverse grid webs (5) formed, rectangular grid structure, wherein - a knitted lattice structure of carrier and binding threads (1.1, ... 1.4, 2.1, ..., 2.4, 3.1, .., 3.4) is formed; the transverse grid webs (5) are each formed by adjoining sections of at least two adjacent meander-shaped carrier threads (1.1, ... 1.4, 2.1, ..., 2.4), - The longitudinal lattice webs (6) in each case by adjoining sections of at least two carrier threads (1.1, ... 1.4, 2.1, ..., 2.4) are formed, which with at least one knit of at least one binder thread (3.1, .., 3.4 ) are entwined; and - The lattice structure is coated on both sides with a thermoplastic plastic coating.

Description

The invention relates to a knotless fish breeding grid, with a rectangular lattice structure formed by longitudinal lattice webs and transversely extending transverse lattice webs.

Nets are used to form aquaculture cages in aqua farms, with a diameter of more than 100 m. The nets are provided with sewn-on straps to attach them to buoyancy bodies. In the case of algae growth, depending on the degree of soiling, the nets are brushed under water or completely removed from the water and washed. Conventional nets scrub in the cleaning process partly, especially because of the rough seams, and must then be manually patched.

Traditionally, fishing nets are made of strings, whereby at the crossing points in each case a knot takes place; the connection of strings over nodes also corresponds to the original definition of a network.

The DE1585538A describes a knotless braided net and its manufacture. From the WO2011 / 155847A1 there is known a similar knotless fish farming grid having monofilament meshes formed by Raschel knitting processes. Longitudinal webs and transverse webs are similar formed, each consisting of at least four interwoven threads so that longitudinal and transverse grid webs are relatively thick, thereby forming a large surface for the settlement of marine organisms such as a large flow resistance.

The DE 43 01 232 C2 describes the production of a net-like fabric by a knitting process. However, this aims at a high structural variability, that is, the mesh size should be easy to change, which is diametrically opposed to the application as a fish breeding grid. If a higher mesh stability is to be achieved, chemical and thermal fixations are proposed by which the thread strength is reduced.

The object of the invention is to provide a knotless fish breeding grid with high mesh stability, which is resistant to wear and easy to clean and which even with smaller mesh sizes has a small web width to keep overall the flow resistance of the fish breeding grid in the water.

• Es ist auf einer Kettenwirkmaschine gut maschinell zu fertigen.
• Es können stabile Fäden mit großem Titer verwendet werden, ohne dass die Stege zu breit werden und das Verhältnis von Stegbreite zu Maschenweite zu groß wird.
• Nur an den Längsgitterstegen wird durch den Bindefaden eine Verdickung erzielt, die aber durch den Beschichtungsprozess nahezu vollständig kompensiert wird. An allen Quergitterstegen ist der Strömungswiderstand mangels Bindefäden ohnehin reduziert.
• Dadurch, dass zwei Gruppen von mäanderförmig gelegten Trägerfäden mit zueinander gegensätzlicher Ausrichtung aufeinander gelegt werden , werden bei der anschließenden Einbindung mit dem Bindefaden stabile Kreuzungspunkte geschaffen.
• Das Fischzuchtgitter nach der Erfindung besitzt konstante Maschenweiten und besitzt bereits ohne Beschichtung eine hohe Maschenstabilität.
• Die thermoplastische Beschichtung, insbesondere PVC-Beschichtung, glättet die Oberfläche, reduziert den Bewuchs, erleichtert die Reinigung und erhöht zusätzlich die Maschenstabilität. Besonders wichtig ist, dass die Beschichtung das nachträgliche Anschweißen von Gurten und dgl. ermöglicht, ohne die Grundstabilität des Gitters zu beeinflussen und zu schwächen. Aufhänggurte müssen somit nicht mehr angenäht werden, wodurch raue Nahtzonen vermieden werden und zudem der Fertigungsaufwand sinkt.
• Die Verwendung von Multifilamenten hat im Zusammenhang mit der Beschichtung folgenden weiteren Vorteil: Der Auftrag der Beschichtung erfolgt am fertigen Gitter, das zum einen unter Zugspannung steht und zum anderen durch Quetschwalzen läuft. Durch diesen Behandlungsschritt werden die Stege gestrafft; gerade die Multifilamente in den Querstegen werden bei der Beschichtung dadurch deutlich dünner als im unbeschichteten Zustand. Die Beschichtung reduziert also auch die Stegbreite und damit den Strömungswiderstand.

This object is achieved by a fish breeding grid with the features of the preamble of claim 1, which has several advantages:

• It is easy to machine on a warp knitting machine.
• Stable high denier yarns can be used without the webs becoming too wide and the web to mesh width ratio becoming too large.
• Only at the longitudinal grid webs is thickening achieved by the binder thread, which is almost completely compensated by the coating process. At all the transverse grid webs, the flow resistance is reduced in any case due to lack of binding threads.
• Characterized in that two groups of meander-shaped support threads are placed on each other with mutually opposite orientation, In the subsequent integration with the binding thread stable crossing points are created.
• The fish breeding grid according to the invention has constant mesh sizes and already without coating has a high mesh stability.
• The thermoplastic coating, especially PVC coating, smoothes the surface, reduces the growth, facilitates cleaning and additionally increases the mesh stability. It is particularly important that the coating allows the subsequent welding of belts and the like, without affecting and weakening the basic stability of the grid. As a result, suspension straps no longer have to be sewn, which avoids rough seam zones and also reduces production costs.
• The use of multifilaments in connection with the coating has the following further advantage: The coating is applied to the finished grid, which is on the one hand under tension and on the other hand passes through nip rolls. By this treatment step, the webs are streamlined; In particular, the multifilaments in the transverse webs are significantly thinner during the coating than in the uncoated state. The coating also reduces the web width and thus the flow resistance.

The coating is preferably carried out by the known plastisol dipping method. A plastisol is a physical mixture of a powdered thermoplastic polymer and plasticizers. The plastisol mixture is stably storable without gelling. Only by tempering, ie heating for a few minutes at typically 160 to 180 ° C, the mixture by partial evaporation of the plasticizer to a permanently viscoelastic plastic.

The fish breeding grid according to the invention is therefore initially finished and then passed as a finished web through a plastisol dip, the Grid - as described - under tension. After passing through the dipping bath, it passes through at least a pair of nip rolls to strip off excess plastisol. Thereafter, the annealing is carried out by heating to about 180 ° C. This creates a solid, but flexible and elastic coating that completely encloses the threads in the longitudinal and transverse webs.

In addition to PVC coatings, polyurethane coatings can also be used.

The mesh size can be up to 35 mm, depending on the fish species to be cultivated, but is typically only about half. According to the invention, it is particularly possible, even with small mesh sizes of, for example, 17 mm to keep the plastic-coated webs narrow with only 2 - 3 mm web width and a width ratio of web width to mesh size of about 15%: 85% not to be exceeded.

Fig. 1

eine erste Gruppe von Trägerfäden;

Fig. 2

eine erste und eine zweite Gruppe von Trägerfäden, und

Fig. 3

ein fertiges Fischzuchtgitter.

The invention will be explained in more detail with reference to the embodiment shown in the drawings. The figures show each in plan view:

Fig. 1

a first group of carrier threads;

Fig. 2

a first and a second group of carrier threads, and

Fig. 3

a finished fish breeding grid.

The FIGS. 1 to 3 show progressively more and more details on the structure of a fish breeding lattice 10 according to the invention, wherein the order of the graphical representation of the components in the figures does not match the production order.

FIG. 1 shows four carrier threads 1.1, ..., 1.4. The production direction runs, as indicated by the block arrow, in the vertical direction. Every carrier thread 1.1, ..., 1.4. is laid meandering for itself, that is, in alternating sequence legs are formed, which run longitudinally - in the direction of production - and then again across it. As a result, first parts of transverse and longitudinal lattice webs 5, 6 are created. The touching corners of adjacent carrier thread 1.1, ..., 1.4 represent the later crossing points 7.

In order to obtain a fish mesh with square mesh, the length of the vertical and horizontal sections is the same size, but also the setting of different lengths is possible if rectangular grids are to be formed.

Order in the schematic representation of FIG. 1 and in the following figures to be able to identify the carrier threads individually, adjacent carrier threads are alternately dashed and drawn with solid lines. All adjacent carrier threads 1.1, ..., 1.4. but they are actually similar. They consist of synthetic fiber multifilaments and have the same titer.

In FIG. 2 is a second group with other carrier threads 2.1, 2.2, 2.3, 2.4 added, which are also shown by dashed lines and drawn by solid lines to distinguish. The opposite to the representation in FIG. 1 Added carrier threads 2.1, 2.2, 2.3, 2.4 are each drawn here as double lines. They have the same meandering configuration as the first group of carrier threads 1.1, 1.2, 1.3, 1.4, except that they are arranged offset by a length of a longitudinal web 6 to the first group, so that in each case a longitudinal web of the first group of carrier threads 1.1, 1.2, 1.3, 1.4 rests against a longitudinal web of the second group of carrier threads 2.1, 2.2, 2.3, 2.4 without being connected thereto. Put simply, the first group of carrier threads 1.1, 1.2, 1.3, 1.4 is a mirror image of the second group of carrier threads 2.1, 2.2, 2.3, 2.4. Due to the fact that in each case one carrier thread of the first and the second group in each case via a Crossing point 7 runs, results in the good mesh stability according to the invention.

At the in FIG. 2 illustrated configuration of both groups of carrier threads 1.1, ..., 1.4, 2.1, ..., 2.4, which are superimposed, the structure of the fish farming grille 10 according to the invention is already clear. The formation of square meshes is already recognizable, in which two webs 5, 6 of adjacent carrier yarns 1.1,..., 1.4, 2.1,..., 2.4 lie next to one another both in the longitudinal direction and in the transverse direction, without these being linked together or otherwise as connected.

The completion of the fish breeding grid is done by a final connection of the previously in the FIGS. 1 and 2 shown, formed by the carrier threads 1.1, ..., 2.4 basic structure, and indeed the connection is made by binding threads 3.1, ..., 3.5, which in the illustration in FIG. 3 have been added.

The binding threads 3.1, ..., 3.5, are indicated here only as zig-zag lines. However, it is in each case a knitted fabric of a binding thread per longitudinal web, by which two longitudinal webs of adjacent carrier threads 1.1, ... 1.4, 2.1, ..., 2.4 are enveloped and wherein in particular the intersection points 7 are involved without the crossing points 7 node formation takes place.

In FIG. 3 are the binding threads 3.1, ..., 3.5 each still not quite up to the upper edge of the grid of carrier threads 1.1, ... 1.4, 2.1, ..., 2.4 laid. This also corresponds to the actual mode of production: The wales are formed continuously on a warp knitting machine from the binding threads 3.1, ..., 3.5. Before that, a new, U-shaped loop is placed in each case by means of partial weft insertion in all adjacently guided carrier threads, before the longitudinal webs of the adjoining webs of the first and second groups of carrier threads are reached by the respective binder thread and enclosed in a loop formed by the binder thread ,

The meander shape in the course of the carrier threads 1.1, ... 1.4, 2.1, ..., 2.4 has the advantage that in the finished grid, the transverse and longitudinal parts of the grid can not be moved against each other without effort, although at the intersection points no knotting or welding takes place, but the crossing point is fixed only by the inclusion in the binding thread.

In this way, according to the invention, a knotless fish breeding grid 10 is created, which already in the raw state, ie without coating, has a high stitch stability. If you reach into the mesh of the knitted fish breeding grid, they are not easy to expand. Thus, even in the raw state, there is no danger of the mesh expanding itself through the activities of the trapped fish or even due to penetrating foreign bodies. Although in the raw state, the loosely adjacent transverse webs of the carrier threads can be gripped and pulled something from the running in the longitudinal direction, wrapped by the binding threads section. For this, however, a greater force is already required, which also does not lead to larger shifts in the lattice structure, but at best has an effect on the immediately adjacent portion of the same carrier thread until the next 90 ° turn.

The stitch stability increases in the preferred embodiment of the invention, which provides a complete covering of all webs of the fish breeding grid 10 with a PVC coating, for reasons of antifouling protection and improved cleaning possibilities alone. Due to the PVC coating, not only are all the transverse and longitudinal webs completely encased and partially glued together, but in particular the crossing points are additionally fixed and the stitch stability with the coating is further increased. The coating forms a smooth surface, reduces the attachment of marine organisms such as algae and barnacles, and facilitates subsequent cleaning of the fish farm lattice 10.

Claims (4)

Knotless fish breeding lattice (10), with a rectangular lattice structure formed by longitudinal lattice webs (6) and transversely extending transverse lattice webs (5),
characterized, - That a knitted lattice structure of carrier and binding threads (1.1, ... 1.4, 2.1, ..., 2.4, 3.1, .., 3.4) is formed; that the transverse grid webs (5) are formed in each case by abutting sections of at least two adjacent, meander-shaped carrier threads (1.1, ... 1.4, 2.1, ..., 2.4), in that the longitudinal lattice webs (6) are each formed by adjoining sections of at least two carrier threads (1.1, ... 1.4, 2.1, ..., 2.4), which are provided with at least one knit of at least one binding thread (3.1,. 3.4) are entwined; and - That the lattice structure is coated on both sides with a thermoplastic plastic coating. Fish breeding grid (10) according to claim 1, characterized in that the binding and carrier threads (1.1, ... 1.4, 2.1, ..., 2.4, 3.1, .., 3.4) are plastic multifilaments and that the denier of the carrier threads (1.1, ... 1.4, 2.1, ..., 2.4) is at least 1.5 times the binding threads (3.1, .., 3.4). Fish breeding grid (10) according to claim 2, characterized in that the titer of the carrier threads (1.1, ... 1.4; 2.1, ..., 2.4) is 5500 to 7500 dtex and the titer of the binding threads (3.1, .., 3.4) 2500 dtex to 4000 dtex. Fish breeding grid according to one of the preceding claims, characterized in that the mesh structure is provided with a plastisol-PVC coating.

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