DE102018111164A1 - Spacer knit and method for its production - Google Patents

Abstract

The invention relates to a spacer fabric (10) and a method for its production. The spacer fabric (10) has a first layer (11) formed by stitches (13), a second layer (12) formed by stitches (13) and connecting threads (21) which cover the two layers spaced apart in a height direction (H) (11, 12). In each layer at least one predetermined separation point (22) is formed, at which the tensile strength is reduced. The meshes (13) are each formed by a bundle of threads, which has a first thread (16) and a second thread (17). The threads (16, 17) have different physical and / or chemical properties, for example, different melting points, different resistance to alkaline or acidic agents, etc. Thus, the second thread (17) at the at least one predetermined separation point (22) selectively severed or in weakened its tensile strength, whereas the at least one first thread (16) at the predetermined separation point (22) is not severed and is preferably not significantly reduced in its tensile strength.

Description

The invention relates to a spacer fabric which represents a three-dimensional textile structure. In contrast to textile fabrics, the spacer fabric has two layers spaced apart in one height direction and each having a plurality of wales and rows of stitches, which layers are connected to one another by connecting threads or pile threads. The spacer fabric therefore forms a three-dimensional textile structure.

Such spacer fabrics are known and can be used for different applications. This in EP 1 860 218 A1 Spacer knit described should be easily separable at a predetermined location. The wales in the two layers of AbstandWirks are connected by weft threads together. This firmer and less strong weft threads are used to connect the wales. In the longitudinal direction, parallel to the wales, a predetermined separation point between two wales can be formed by the less solid weft threads.

This in DE 10 2008 046 437 A1 described spacer fabric is similar to that in EP 1 860 218 A1 built up. Over the width of the Abstandsgewirks in the direction of the courses evenly distributed pairs of wales are provided, which are connected to a less solid weft thread and therefore each define a predetermined separation point in the direction of the wales.

To create predetermined separation points in a transverse direction, substantially parallel to the courses, this indicates DE 10 2010 010 524 A1 Known distance fabric a basic thread system and another thread system in the two spaced layers. The threads of the basic thread system are more stable or tear-resistant than the threads of the additional thread system. At least one row of stitches is formed by the stitches of the thread of the further thread system. The course has a lower stability and connects the two adjacent stitches of the wale, which are formed from a thread of the basic thread system. The course of stitches from the thread of the further thread system represents a predetermined separation point in the transverse direction parallel to the course direction of the courses.

Starting from the known distance knitted fabrics, it is an object of the present invention to achieve a predetermined separation point in the longitudinal direction and / or transverse direction of the spacer fabric with a simple structure.

The object is achieved by a spacer fabric having the features of claim 1 and a method having the features of claim 9.

The spacer fabric has a stitched first layer and a stitched second layer. The stitches form wales in each layer in a longitudinal direction and courses in a transverse direction. The longitudinal direction and the transverse direction are aligned at right angles to each other. The stitch are formed by a bundle of threads comprising a first thread and a second thread. The two threads are not twisted together, twisted, glued or otherwise directly connected. For example, a yarn feed of the knitting machine, in particular a perforated needle, fed to the formation of the yarn bundle of the first thread and the second thread fed to stitch formation. The two threads are placed side by side.

In a height direction perpendicular to the longitudinal direction and at right angles to the transverse direction, the two layers are arranged at a distance from each other and connected to each other by connecting threads. As a result, a three-dimensional structure of the spacer fabric is achieved.

In each situation, at least one predetermined breaking point is formed. Along the predetermined separation point, the at least one second thread, which extends either along the predetermined separation point or crosses the predetermined separation point, is severed or at least weakened in its tensile strength. The stitches of the first layer and the second layer can therefore tear very easily along the at least one predetermined separation point. The targeted weakening of the second thread can be achieved, for example, physically or chemically after working, by, for example, cutting along the at least one predetermined separation point, e.g. Energy in the form of heat is introduced onto the spacer fabric or by e.g. an agent, preferably a fluid, is applied. The chemical and / or physical properties of the first thread and the second thread differ, so that the second thread can be weakened or severed selectively at the predetermined separation point. The at least one first thread, which extends along the predetermined separation point or crosses the predetermined separation point, is maintained continuously in order to maintain the stitches in the layers and is not cut at the at least one predetermined separation point.

The chemical and / or physical weakening of the second thread along the predetermined separation point can be done in principle in any path or contour. Thus, predetermined breaking points with essentially any shape can be formed in the spacer fabric. When applying a chemical substance, for example, a template can be taken to help in order to apply the substance for weakening or separation of the at least one thread targeted to the at least one predetermined separation point.

The predetermined separation point can thus be adapted very easily and flexibly to the different requirements. For example, the predetermined separation point may correspond to the course of an airbag flap. The spacer fabric is often used for instrument panels for relining the leather surface or artificial leather surface and must not hinder the opening of an airbag. The spacer fabric according to the invention can be easily and flexibly adapted to different shapes and sizes of the airbags.

In one embodiment, the first thread and the second thread are made of different materials. As a result, different chemical and / or physical properties are achieved, so that a targeted weakening of the second thread is possible and the stitch connection in the layers of the spacer fabric along the predetermined separation point is maintained by the first thread.

In one embodiment, the material of the first filament has a higher melting temperature than the material of the second filament. By introducing heat above the melting temperature of the second thread and below the melting temperature of the first thread, the second thread can be selectively weakened along the at least one predetermined separation point. The heat can be registered without contact, for example by means of electromagnetic radiation, preferably using a laser beam.

In one embodiment, the material of the first filament may have better alkali resistance than the material of the second filament. By applying an alkaline substance, the second thread can be weakened or severed, with the first thread not being severed to maintain stitching. Alternatively or additionally, it is also possible that the material of the first thread has a better acid resistance than the material of the second thread. To weaken the second thread, an acid substance can be applied along the at least one predetermined separation point.

In order not to sever the first thread by the application of an alkaline agent or acid, the alkaline agent or the acid can be washed out after a certain exposure time, so that although the second thread along the predetermined separation point is weakened or severed, the stitch formation by the first thread but maintained in any case.

It is advantageous if the first layer and / or the second layer is executed without weft thread. The wales of the layers are connected depending on the type of binding used at least outside both by the first thread, as well as by the second thread. Along the predetermined separation point, the second thread can be severed. As a binding type, a fringe weave, a tricot weave, a cloth weave, a satin weave, a twill weave or a velvet weave may be used in the first layer and / or the second layer. The structure of the layers and their production is very simple and the entry of a weft thread can be omitted.

Preferably, the connecting threads are arranged such that they do not cross or pass through a predetermined separation space. The desired separation space is a region of the spacer fabric defined by associated desired separation points in the first layer and in the second layer. The predetermined separation space extends from the predetermined separation point in the first layer to the predetermined separation point in the second layer, which are preferably aligned with one another in the longitudinal direction and height direction. Adjacent to this predetermined separation space, the connecting threads can be arranged, for example, without offset in the transverse direction, for example in the form of a so-called I-laying.

For the preparation of the spacer fabric described above, the procedure is as follows:

First, the spacer fabric is produced on a knitting machine. In this case, the first thread and the second thread are fed to each other without direct connection for stitch formation. All stitches in the first layer and the second layer are formed using the first thread and the second thread. The two layers are joined together when working through the spacer threads. The density and arrangement of the spacer threads may be varied to desirably adjust the compression strength of the spacer fabric in the height direction.

After the spacer fabric has been produced, in each case at least one predetermined separation point is formed in the first layer and in the second layer. Along the predetermined separation point, the second thread is weakened and preferably severed. The first thread remains along the intended separation point, so that the stitches in the layers do not dissolve. Therefore, at least one first thread is not severed along the predetermined separation point. The weakening of the at least one second thread along the predetermined separation point is effected by a physical and / or chemical action. by virtue of the different physical and / or chemical properties of the first thread and the second thread can be targeted a weakening of the second thread can be achieved.

In a preferred embodiment, the weakening of the at least one second thread along the at least one predetermined separation point is effected by the introduction of energy, preferably heat. The energy is preferably introduced without contact, for example using electromagnetic radiation, in particular a laser beam.

Alternatively or in addition to the introduction of energy, a chemical agent can be applied to the first layer and the second layer along the at least one predetermined separation point. The chemical agent may be alkaline or acidic, depending on whether the second thread is less alkali-resistant or less acid-resistant compared to the first thread. Thus, a targeted weakening of a second thread can be achieved by chemical means.

• 1 eine schematische Prinzipdarstellung von Maschenstäbchen und Maschenreihen eines Ausführungsbeispiels eines Abstandsgewirks,
• 2 eine schematische perspektivische Ansicht einer Masche bzw. Fadenschlaufe aus einem ersten Faden und einem zweiten Faden, wie sie in der ersten Lage und der zweiten Lage des Abstandsgewirks gebildet wird,
• 3 eine stark schematisierte Darstellung eines Ausführungsbeispiels eines Abstandsgewirks mit Blick in einer Längsrichtung parallel zu den Maschenstäbchen nach dem Herstellen des Abstandsgewirks in einer Wirkmaschine,
• 4 die Darstellung des Abstandsgewirks gemäß 3, wobei das Bilden einer Solltrennstelle in jeder Lage schematisch dargestellt ist,
• 5 und 6 Maschen in Draufsicht auf eine der Lagen in der Darstellung gemäß 1, wobei jeweils eine Solltrennstelle schematisch veranschaulicht ist.

Advantageous embodiments of the invention will become apparent from the dependent claims, the description and the drawings. Hereinafter, preferred embodiments will be explained in detail with reference to the accompanying drawings. Show it:

• 1 1 is a schematic diagram of wales and courses of an embodiment of a spacer knit;
• 2 a schematic perspective view of a loop or thread loop of a first thread and a second thread, as formed in the first layer and the second layer of the Abstandsgewirks,
• 3 a highly schematic representation of an embodiment of a spacer fabric viewed in a longitudinal direction parallel to the wales after the production of the spacer fabric in a knitting machine,
• 4 the representation of the Abstandgewirks according to 3 wherein the forming of a predetermined separation point in each layer is shown schematically,
• 5 and 6 Mesh in plan view of one of the layers in the illustration according to 1 , wherein in each case a predetermined separation point is illustrated schematically.

In the 3 and 4 is in each case highly schematic one embodiment of a spacer fabric 10 shown. The spacer fabric 10 has a first location 11 and a second location 12 , The two layers 11 . 12 are each through a variety of stitches 13 formed in a longitudinal direction L wales 14 and in a transverse direction Q , perpendicular to the longitudinal direction L , Stitches 15 form ( 1 ).

To form each stitch 13 becomes a first thread 16 and a second thread 17 used. As it is schematic in 2 is illustrated, are the two threads 16 . 17 next to each other and are not directly connected. They lie loosely against each other. In particular, the first thread 16 with the second thread 17 not glued, twisted, twisted or otherwise directly connected.

The two threads have different chemical and / or physical properties and can be made of different materials. Preferably, both threads are 16 . 17 around synthetic fibers. In the embodiment illustrated here, both threads have 16 . 17 the same thread size / yarn count, for example at least 11 dtex. As material for the threads 16 . 17 For example, a plastic material, preferably polyester, polyamide or polypropylene can be used. In the embodiment illustrated here, the first thread is made of high-melting polyester and the second thread is made of low-melting polyester. The material of the first thread 16 thus has a higher melting point than the material of the second thread 17 ,

Using the two threads 16 . 17 become the meshes 13 both in the first location 11 , as well as in the second position 12 educated. The type of binding can vary. The two layers 11 . 12 are executed without a thread. The wales 14 are joined together during stitching using the first thread 16 and the second thread 17 , For example, change over a common thread feed supplied first thread 16 and second thread 17 always between two adjacent wales 14 back and forth and the threads 16 . 17 Form alternately in successive courses 15 a mesh 13 in a wad and then a stitch 13 in the next course 15 in each other wales 14 , This bond is schematic in the 1 . 5 and 6 shown. As already explained, other types of bonds can also be used. In the 1 . 5 and 6 is the view in the height direction H each on the outside of the first layer 11 or the second layer 12 illustrated.

The first location 11 and the second location 12 of the spacer knit 10 are in a height direction H , perpendicular to the longitudinal direction L and perpendicular to the transverse direction Q spaced apart. The distance between the two layers 11 . 12 can be dependent of the desired thickness of the spacer fabric 10 vary.

The first location and the second location 12 are by connecting threads 21 connected with each other. The number and arrangement of connecting threads 21 per unit area in one by the longitudinal direction L and the transverse direction Q spanned level may vary to the desired compressive strength of the spacer knit in the height direction H to reach.

The material of the connecting thread 21 may be the material of the first thread 16 and / or the second thread 17 correspond. It is also possible, the at least one connecting thread 21 to form by another, third thread extending from the first thread 16 and the second thread 17 with regard to the material and / or the physical properties and / or the chemical properties.

Here in the highly schematized in the 3 and 4 illustrated embodiment, the connecting threads run 21 each in the longitudinal direction L arranged rows between a wale 14 the first location 11 and a wale 14 the second location 12 , It is a so-called I-Legung. In a modification to the illustrated embodiment, the connecting threads could 21 also in the transverse direction Q diagonally between in height direction H not directly superimposed wales 14 the two layers 11 . 12 run.

According to the invention is in the first position 11 and in the second position 12 of the spacer knit 10 in each case at least one predetermined breaking point 22 educated. The target separation point 22 can, for example, between two wales 14 longitudinal L extend ( 5 ) or along a course 15 in the transverse direction Q ( 6 ). The at least one predetermined separation point 22 may also be curved and / or angled at one or more locations or describe a free-form path. The course of the target separation point 22 within through the longitudinal direction L and transverse direction Q spanned level is basically arbitrary. Preferably, a predetermined separation point is aligned 22 in the first position 11 and a target separation point 22 in the second position 12 in the height direction H considered each other, so the two layers 11 . 12 at a tensile load above a threshold, so to speak at the same place tear or split.

Along the Solltrennstelle 22 becomes the at least one second thread 17 , which is the target separation point 22 crossed, weakened and severed by example. The tensile strength of the spacer fabric 10 in the first position 11 and in the second position 12 is along the respective Solltrennstelle 22 therefore essentially only through the first thread 16 determines, whereas the second thread 17 makes no or only a small contribution to the tensile strength. The tensile strength of the compound outside the at least one predetermined breaking point 22 is thus larger. At a load of Abstandgewirks 10 with a corresponding tensile force tears the spacer fabric 10 in the first position 11 and in the second position 12 therefore along the at least one predetermined breaking point 22 on.

To the at least one second thread 17 along the at least one predetermined breaking point 22 to weaken energy is introduced in the form of heat in the embodiment described here. As it is highly schematized in 4 is illustrated, the introduction of heat contact by means of electromagnetic radiation and, for example by means of a laser beam 23 a laser 24 respectively. The entry of the heat can be in the first position 11 and in the second position 12 be done simultaneously or in chronological order. The laser 24 or the laser beam 23 is guided in the the Solltrennstelle 22 descriptive train along the respective location 11 . 12 moves and brings heat to the first thread 16 and the second thread 17 one.

The introduction of the heat takes place here in such a way that the second thread 17 at least to a temperature corresponding to the melting temperature of the material of the second thread 17 and below the melting temperature of the material of the first thread 16 heated. As a result, the at least one second thread 17 along the predetermined separation point 22 significantly weakened in its tensile strength and severed in the embodiment. The at least one second thread 17 does not necessarily have to be severed. It is also sufficient a plastic deformation, for example, the thread thickness d reduced by at least 30% or at least 50% or at least 70% and / or the a plastic strain along the direction of extension of the second thread 17 causes. With an increased length of the at least one second thread 17 can initially substantially no tensile force through the second thread when a tensile force occurs 17 be picked up until the first thread 16 torn. Will be the second thread 17 not completely severed, the first thread can 16 and the second thread 17 tear sequentially when a sufficiently large tensile load, if by entering the energy and, for example, the heat, a longitudinal expansion of the second thread 17 at the target separation point 22 is done.

The weakening of the at least one second thread 17 along the at least one predetermined breaking point 22 may alternatively be carried out by other means to introduce energy, such as heat. For example, an alkaline Mean or acidic agent along the at least one predetermined breaking point 22 be applied. In such an embodiment, the acid resistance and / or alkali resistance of the material of the first thread is 16 larger than that of the second thread 17 , The duration of action of the acidic or alkaline agent at the at least one predetermined separation point 22 is chosen such that the connection through the first thread 16 at the at least one predetermined breaking point 22 is maintained while the tensile strength of the at least one second thread 17 noticeably reduced or at least a second thread 17 at the at least one predetermined breaking point 22 is completely severed. After a sufficient exposure time, the alkaline or acidic agent at the predetermined separation point 22 for example, be washed out to damage the first thread 16 to avoid.

The course of the target separation point 22 in the respective level 11 . 12 can be achieved along any pathway by introducing energy and / or applying an alkaline or acidic substance. For entering the energy and / or for applying a chemical agent to the at least one predetermined breaking point 22 a template can be used. The application of a chemical agent can be done for example by doctoring. The application of a chemical agent can also in the context of dyeing the Abstandsgewirks 10 respectively.

In the preferred embodiment of the spacer fabric described herein 10 is between a target separation point 22 in the first position 11 and an associated target separation point 22 in the second position 12 a predetermined separation space 25 Are defined ( 4 ). The target separation space 25 becomes at nominal break points 22 extending in the longitudinal direction L in the first position 11 and in the second position 12 extend, not from connecting threads 21 thwarted. The tearing open of the spacer fabric 10 along the predetermined separation points 22 is therefore not due to the connecting threads 21 impaired or impeded.

For other gradients of the nominal separation points 22 can the set separation space 25 of one or more connecting threads 21 to be interspersed. In such an embodiment, the at least one connecting thread 21 that the break room 25 crosses, in the region of the intersection of the Sollentrennraums 25 weakened or severed. For example, the at least one connecting thread 21 to be made of the same material as the second thread 17 and weakened or severed by exposure to a physical and / or chemical agent in the same manner as described above in connection with the second suture 17 at the target separation point 22 was explained.

The invention relates to a spacer fabric 10 and a method for their production. The spacer fabric 10 has one through stitches 13 educated first location 11 , one through stitches 13 formed second position 12 and connecting threads 21 that the two in a height direction H spaced layers 11 . 12 connect. In each position is at least one target separation point 22 formed, where the tensile strength is reduced. The stitches 13 are each formed by a thread bundle, which is a first thread 16 and a second thread 17 having. The strings 16 . 17 have different physical and / or chemical properties, for example, different melting points, different resistance to alkaline or acidic agents, etc. Thus, the second thread 17 at the at least one predetermined breaking point 22 selectively severed or weakened in its tensile strength, whereas the at least one first thread 16 at the target separation point 22 is not severed and is preferably not significantly reduced in its tensile strength.

LIST OF REFERENCE NUMBERS

10

spacer fabric

11

first location

12

second location

13

mesh

14

wales

15

wale

16

first thread

17

second thread

21

connecting thread

22

Predetermined breaking point

23

laser beam

24

laser

25

Predetermined separating space

d

denier

H

height direction

L

longitudinal direction

Q

transversely

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1860218 A1 [0002, 0003]
• DE 102008046437 A1 [0003]
• DE 102010010524 A1 [0004]

Claims (11)

Spacer knit (10) with a mesh (13) having first layer (11) and a mesh (13) having second layer (12), wherein the mesh (13) in a longitudinal direction (L) wales (14) and in a transverse direction (Q) perpendicular to Form longitudinal course (L) courses (15), the stitches (13) being formed by a bundle of threads comprising a first thread (16) and a second thread (17) which are juxtaposed without direct connection, wherein both layers (11, 12) in a height direction (H) at right angles to the longitudinal direction (L) and the transverse direction (Q) are arranged at a distance from each other and connected by connecting threads (21), wherein in each layer (11, 12) along at least one predetermined separation point (22) of the at least one second thread (17) is severed and / or weakened in the tensile strength. Distance fabric after Claim 1 , characterized in that the first thread (16) and the second thread (17) consist of different materials. Distance fabric after Claim 1 or 2 , characterized in that the material of the first thread (16) has a higher melting temperature than the material of the second thread (17). Spacer knit according to one of the preceding claims, characterized in that the material of the first thread (16) has a better alkali resistance than the material of the second thread (17). Spacer knit according to one of the preceding claims, characterized in that the material of the first thread (16) has a better acid resistance than the material of the second thread (17). Spacer knit according to one of the preceding claims, characterized in that the first layer (11) and / or the second layer (12) is designed without weft thread. Spacer knit according to one of the preceding claims, characterized in that the connecting threads (21) do not intersect a predetermined separating space (25) defined by predetermined nominal separating points (22) in the first layer (11) and the second layer (12). Spacer knit according to one of the preceding claims, characterized in that a connecting thread (21), which intersects a predetermined separation points (22) in the first layer (11) and the second layer (12) defined predetermined separation space (25), from the same Material is like the second thread (16). Method of producing a spacer fabric (10) according to one of the preceding claims, comprising the following steps: - producing the spacer fabric (10) comprising the first layer (11), the second layer (12) and the spacer threads (21) connecting the two layers, - Producing at least one predetermined separation point (22) in the first layer (11) and / or the second layer (12) by weakening the at least one second thread (17) along the at least one predetermined separation point (22), wherein the weakening by a physical and / or chemical action is achieved. Method according to Claim 9 , characterized in that the action comprises the introduction of energy into the at least one second thread (17) along the at least one predetermined separation point (22). Method according to Claim 9 or 10 , characterized in that the action comprises the application of a chemical agent on the at least one second thread (17) along the at least one predetermined separation point (22).

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