EP2798103B1 - Insect screen - Google Patents

Description

The present disclosure relates to a thread for making insect screen meshes comprising a core, the core having a coating comprising heat-activatable adhesives for bonding to itself or other threads of the fabric, and wherein the core has a higher melting point than the adhesives having.

Furthermore, the present disclosure relates to a fabric for insect screens having a mesh weave structure comprising warp threads and weft yarns bonded together at junctions with adhesives.

The present invention relates to an insect screen according to claim 1, comprising a frame and a fabric spanned by the frame.

Finally, the present invention relates to a method of manufacturing insect screen meshes, comprising the steps of a) providing threads as warp threads and weft threads, b) weaving a fabric by means of the warp threads and weft threads, and c) heating the fabric to a temperature higher than the melting point of the adhesives and less than the melting point of the core is for generating cohesive bonds between the warp yarns and the weft yarns at their junctions.

Insect screens are used behind openable windows. They allow the window to be opened, for example for ventilation, without insects being able to penetrate into the room. As a rule, a fabric is clamped in a suitable frame, which is mounted behind the window frame. For the purposes of the present invention, the term tissue is understood as meaning manually or mechanically produced products of the weaving mill comprising at least two, in particular at right angles or at right angles, crossed thread systems. In general, there is a requirement that the fabric as a whole maximum permeability to light and air, but not to insects offers and is as invisible as possible.

A fabric of the type mentioned is for example from the WO 2004/088078 A2 known. In this prior art, it is proposed that the fabric be firmly connected at the node or crossing points between the warp threads and the weft threads. For bonding, an adhesive is suggested. Alternatively, for fusion, heat fusion of the filaments at the nodes or bonding by means of ultrasonic energy is suggested. It is disclosed as disadvantageous that the adhesive does not have the ultraviolet radiation resistance required for the application.

Another insect screen with a fabric of the type mentioned is from the WO 2003/067015 A1 known. The fabric disclosed there is provided with a thin coating which makes the fabric look dull black and additionally causes a weak solidification at the nodes of the threads.

From the DE 10 2009 007 748 A1 a fabric for insect screens is known, in the production of which the warp threads and weft threads are glued together by means of a polyester resin in aqueous solution. The resulting fabric is very stable and has a high permeability to light and air. However, in the manufacturing process, the polyester resin blinds a not insignificant number of meshes of the fabric, with the fenestrated meshes being clearly visible to the human eye. Meshes with fenestrated mesh are rejects for their desired use, namely as invisible insect screens as possible.

The JP 2000 290 856 A describes a foldable fabric for insect screens for attachment to doors or windows. The fabric has a mesh weave structure and includes knit yarns and weft yarns bonded together at junctions by means of adhesives. The threads are formed as bicomponent threads with a core and a coating. The coating contains a heat-activatable adhesive which has a lower melting point than the core. During production, the fabric is heated, whereby the warp threads and the weft threads are welded together at their nodes. If the fabric is installed in a humid ambient climate, the meshes of the fabric will fade from the threads due to moisture precipitation. The insect screens made of this fabric are clearly visible and disturb the perception of a viewer when looking through the grid.

The present invention is therefore based on the object to provide an insect screen and a method for producing tissues for insect screens of the type mentioned in order to avoid the disadvantages associated with the prior art.

The visibility of insect screen meshes depends mainly on window meshes during fabric manufacture, fluid build-up on fabric threads in the installation situation, and on the color of the threads.

According to the present disclosure, the object directed to the thread is achieved with a thread of the type mentioned above, the coating of which comprises hydrophobic repelling agents.

With great advantage, the thread of the insect screen according to the invention is automatically equipped with the required for its processing adhesive. The thread according to the insect screen according to the invention allows a localized bonding of warp threads and weft threads at nodes of the fabric. A global application of an adhesive in the form of an aqueous solution, which can lead to the fencing of mesh, is avoided according to the invention. The inventive choice of a heat-activatable adhesive, the handling of the thread in a deactivated, non-sticky state, which is present according to the invention at all natural ambient temperatures, completely problem-free. The activation of the adhesive takes place in a very simple way, namely by heating. About the temperature can thus be very accurate control when the thread is adhesively activated or deactivated according to the insect screen according to the invention is. For this purpose, it proves to be particularly advantageous according to the invention that the core has a higher melting point than the adhesives. Thus, the adhesives can be melted and thus tack-activated, but without the core melting or substantially softening to prevent tearing of the thread during bonding. Since the temperature is a very well controllable process size, the industrial production of the thread and also the fabric can be carried out under simple and thus cost-effective conditions. The invention encompasses coatings which completely cover the thread, but also those which are formed as strips parallel to the longitudinal axis of the thread or rings of finite width running along the circumference of the thread. Even discrete, dot-like coating patterns are provided according to the invention. The thread according to the insect screen according to the invention is particularly efficient for an invisible as possible tissue for insect screens processed.

With great advantage, the coating according to the invention comprises hydrophobic repellent. Such repellents prevent the accumulation of humidity and water droplets on the thread, whereby it remains dry. If the thread is supplied to its determination according to the invention, namely for the manufacture of fabrics for insect screens, the hydrophobic repelling agents prevent the stitching of stitches by water drops, so that the fabric remains invisible even at high humidity or precipitation.

The coating may also include colorants. By adding colorants, the color of the thread can be defined during its production. It is well known that insect screen meshes are perceived by the viewer to be less distracting when viewed through a dark color. So it's special advantageous if the thread from which fabric for insect screens are made, is dark in color.

In a particularly advantageous embodiment of the present invention The invention comprises the core of a polyester, in particular polyethylene terephthalate (PET), and the coating as an adhesive polyolefin, in particular polyethylene (PE). PET and PE are able to make a material connection. As a result, the coating is inextricably bonded to the core, so that the coating does not peel off, for example, in the case of a strong curving or kinking of the thread. The inventive functionality of the thread thus remains in principle for an infinitely long time. Furthermore, the pair of PET and PE excellently meets the above melting point condition, since PET has a melting point greater than 250 ° C, but PE melts as low as 130 ° C. A process temperature for bonding the warp threads and weft threads of the fabric is therefore to be chosen advantageously from a closed by the two melting points interval. The fabric pair PET and PE selected in this embodiment is outstandingly suitable for producing the thread according to the invention by means of coextrusion of core and coating.

In a particularly advantageous embodiment of the present invention, the coating contains as a repellent fluorinated polyolefin, in particular polytetrafluoroethylene (PTFE). It has been found that PTFE is particularly suitable on the one hand for application to the core and on the other hand in terms of its hydrophobic effect.

So that the per se transparent PE does not appear whitish upon heavy mechanical loading of the thread, according to the invention it is alternatively or additionally provided that the coating has carbon black as colorant. Soot-enriched PE appears optically black and thus, as a PE-coated fabric, is less visible than milky white fabric. In addition, the soot particles stabilize the inventive filament against ultraviolet radiation, which is important for sun-exposed fabric of insect screens to extend their durability.

It is inventively provided with great advantage that the thread can be produced by coextrusion of core and coating. The Forming processes of extrusion are ideal for producing continuous products, such as threads. In the coextrusion used according to the invention, for example, feed a first extruder PET and a second, independent of the first extruder extruder PE in the nozzle of the extrusion machine, the PET strand and the PE strand united in the nozzle and pulled together endlessly by a tool become.

In addition, it is provided in an embodiment of the invention that between the core and the coating adhesive, in particular cyanoacrylate, are arranged. Depending on the specific PET-PE combination and a resulting bond strength between the core and the coating of the thread, it may be advantageous in the case of particularly heavy mechanical loading of the thread to increase the bond strength with adhesive in order to prevent damage to the coating. Such damage, for example microcracks, would lead to the normally transparent PE becoming milky white perceptible and the fabric for insect screens no longer being invisible.

Furthermore, it proves to be particularly advantageous according to the invention if the core has a thickness of less than 0.20 mm, in particular equal to 0.15 mm. Such a thread thickness is an optimum in terms of the generally desired low visibility of the fabric on the one hand and the required strength of the fabric on the other hand.

According to the present invention, in a fabric of the type mentioned at least some of the warp threads and / or weft threads are formed as threads according to the invention. The advantages described in connection with the thread according to the insect screen according to the invention naturally extend to the tissue. The thin and stable threads according to the invention allow the weaving of a resistant fabric with a large mesh size relative to the thickness of the threads. Such a fabric is very translucent and thus almost invisible. For a fabric to qualify as an effective protection against insects, it requires a mesh size that is so small that insects to be kept can not slip through. In particular, it may not be relative to each other during use of the insect screen to displacements of warp threads or weft threads, otherwise the maximum allowable mesh size could be at least locally exceeded for effectively blocking out insects. In the fabric constructed of threads according to the insect screen according to the invention according to the insect screen according to the invention the warp threads and weft threads are glued together at their nodes with great advantage and the mesh size of the fabric permanently fixed. A subsequent shifting of individual threads within the fabric is excluded. Due to the multiple cohesively connected threads fabric of the invention is stable and dimensionally stable, resulting in a particularly simple handling and good processability. Furthermore, the fabric according to the insect screen according to the invention has a high permeability to light and air and is almost invisible.

In a particularly advantageous embodiment of the invention it is provided that the fabric has a mesh size of 0.7 mm to 1.7 mm, in particular 1.1 mm. A mesh size chosen from this interval advantageously falls below the size of the slip, which prevents disturbing insects from passing through the tissue, while at the same time ensuring sufficient permeability to air and light.

In insect screens, the tissue is usually the am Most failure-prone component, which leads to the failure of the entire insect screen. With great advantage, the particularly resistant fabric gives the insect screen according to the invention a significantly superior stability and durability compared to conventional insect screens. Thus, less waste arises during the manufacture and assembly of insect screens according to the invention. The insect screen according to the invention is invisible in the installation situation.

According to the present invention, the object directed to the method is achieved with a method of the type mentioned above, wherein at least some of the warp threads and / or weft threads are formed as threads according to the invention and it comprises a step d) hydrophobizing the fabric. The use of the threads according to the invention enables the production of the extremely advantageous fabrics according to the invention basically. However, for the actual establishment of the necessary material connection of warp threads and weft threads at their nodes, it is necessary to activate the adhesive. The activation of the adhesive takes place by means of heating. With great advantage, the method according to the invention provides a step in which the fabric having threads according to the invention is heated, as a result of which the adhesive is activated and thus material-bonded connections between the warp threads and the weft threads are produced at their nodes. Accordingly, the method according to the invention is outstandingly suitable for producing stable meshes with fixed meshes for insect screens. Since the inventive method, a dipping of the fabric in liquid adhesives or other coating agent containing basins, a windowing of mesh is inventively excluded with great advantage. In addition, the inventive method is particularly efficient and economical, since many cohesive compounds are generated simultaneously and heating a tissue from a process engineering point of view is a very easy to bewerkstelligender process step, without For example, to require additional substances or strict safety measures.

It proves to be particularly advantageous according to the invention that during step c) the fabric is heated to a temperature which is higher than the melting point of the adhesives and lower than the melting point of the core. As a result, the adhesives are activated to allow the advantageous cohesive connections arise. However, since in this process step, the melting point of the core is not reached, this remains stable and consequently the tissue is obtained and manageable.

After heating the fabric to fuse the warp threads and weft threads at their nodes, there may be left in particular regions which are free of hydrophobic repelling agents and thus favor a disadvantageous attachment of atmospheric moisture or water droplets. In order to eliminate this disadvantage, the method according to the invention provides a great advantage of hydrophobizing the woven and bonded fabric, preferably subsequently, in particular finally, as a whole. This process step is equivalent to fully sealing the fabric and provides maximum protection against the deposition of humidity or water droplets on the fabric so that it remains largely invisible even under these adverse environmental conditions.

The invention will be described by way of example in a preferred embodiment with reference to the drawings, wherein further advantageous details are shown in the figures of the drawings.

• Fig. 1 ein erfindungsgemäßes Insektenschutzgitter mit einem Gewebe aus einer Anzahl Fäden,
• Fig. 2a eine schematische Schnittansicht des Gewebes gemäß dem erfindungsgemäßen Insektenschutzgitter entlang der in Fig. 1 markierten Linie II - II in einem verklebten Zustand und
• Fig. 2b eine Detailvergrößerung des Gewebes gemäß dem erfindungsgemäßen Insektenschutzgitter in dem in Fig. 2a markierten Bereich B.

The figures of the drawings show in detail:

• Fig. 1 an inventive insect screen with a fabric of a number of threads,
• Fig. 2a a schematic sectional view of the fabric according to the insect screen according to the invention along the in Fig. 1 marked line II - II in a bonded state and
• Fig. 2b an enlarged detail of the tissue according to the insect screen according to the invention in the in Fig. 2a marked area B.

In Fig. 1 is an inventive insect screen 1 in schematic representation shown. The insect screen 1 consists essentially of a fabric 2, which is enclosed in a frame 3 in unspecified manner, generally known manner. The fabric 2 is constructed from in Fig. 1 vertically extending warp threads 4 and to the warp threads 4 orthogonal weft threads 5. The terms warp 4 and weft 5 are known to refer to the manufacturing process of weaving. In the context of the present invention, however, it does not matter which threads are warp threads 4 or weft threads 5 or were in the production of the fabric 2. The warp threads 4 form with the weft threads 5 in each case at the crossing points node 6. The fabric 2 in Fig. 1 has a weave structure 7 in this way. The warp threads 4 and weft threads 5 are bicomponent threads comprising a core and a coating 11. In the particularly advantageous embodiment presented here, the core comprises polyethylene terephthalate (PET) and the coating 11 polyethylene (PE). On the structure of the warp threads 4 and weft threads 5 will be described below with reference to Fig. 2a and Fig. 2b discussed in more detail.

In Fig. 2a is a part of a schematic sectional view of the fabric 2 along the in FIG Fig. 1 marked line II - II shown in a glued state. The thread thickness 8 of the warp threads 4 is 0.15 mm. Likewise, the thread thickness 9 of the weft threads 5 is 0.15 mm. The mesh size 10 of the mesh 7 is 1.1 mm. The stitches 7 are square shaped. Accordingly, the clear area per mesh 7 is accordingly 1.21 mm ² . In the context of the invention, rectangular or any other mesh shapes are also conceivable. Next is in Fig. 2a It can be seen clearly that the warp threads 4 and weft threads 5 consist essentially of two components, namely a core and a coating 11 surrounding the core. The coating 11 is preferably over the entire lateral surface of the core of both the warp threads 4 and the weft threads 5 applied. The threads 4, 5 are advantageous means Coextrusion produced. The coating 11 contains a heat-activatable adhesive, here PE, and hydrophobic repellents, for example polytetrafluoroethylene (PTFE). The PE and PTFE regions of the coating 11 are then spatially separated from each other. In an additive embodiment of the invention, the coating 11 comprises coloring agents, for example soot particles, in order to improve the optical properties of the thread 4, 5 according to the invention in that a soot-dyed, black thread 4, 5 is less visible than differently colored threads.

In Fig. 2b is an enlarged detail of the tissue according to the invention in the in Fig. 2a marked area B shown schematically. The warp threads 4 and weft threads 5 are connected in the region of their nodes 6 cohesively, namely glued. The adhesive PE required for this purpose is provided by the coating 11. As a result of the bonding, the coatings 11 of all warp threads 4 and weft threads 5 combine to form a one-part coating arrangement which carries all the warp threads 4 and weft threads 5 as stabilizing elements. Since the connections of warp threads 4 and weft threads 5 are limited locally to the nodes 6 and do not protrude into the stitches 7 or even entire stitches 7 verfenstern, the mesh size 10 is practically not reduced. The permeability of the fabric 2 for light and air therefore remains according to the mesh size 10 obtained.

For producing the fabric 2 for an insect screen 1, the method according to the invention provides for the steps known from the prior art a) provision of threads 4, 5 as warp threads 4 and weft threads 5, b) weaving of a fabric 2 by means of the warp threads 4 and weft threads 5 and c) heating the web 2 to a temperature higher than the melting point of the adhesives and lower than the melting point of the core, to generate cohesive bonds between the warp threads 4 and the weft threads 5 at their nodes 6, a step d) hydrophobizing the web Woven fabric 2 before, wherein at least some of the warp threads 4 and / or weft threads. 5 inventive threads 4, 5 are. The heating causes activation of the adhesive of the threads 4, 5. In the case of PET as the core and PE as the adhesive of the threads 4, 5, the woven fabric of these threads 4, 5 is heated to about 140 ° C, whereby the warp threads 4 and Stick weft threads 5 together many times. Since the adhesive is bonded to the core of the threads 4, 5 and is not applied by immersing the fabric 2 in a bath containing liquid adhesive, windowing of meshes 7 is advantageously excluded. After deactivation of the adhesive due to a cooling of the fabric 2 to below 100 ° C, no further compounds can be generated, but the compounds already generated naturally remain. After completion of method step c), the fabric 2 is clearly solidified and has with great advantage fixed nodes, so that the warp threads 4 and weft threads 5 are no longer displaceable relative to each other and a maximum allowable mesh size 10 to effectively retain disturbing insects, under no circumstances is exceeded. To ensure that the fabric 2 does not break down during the step c) by melting the core of the threads 4, 5, it is important to ensure that it is always lower than the melting temperature of the core, here PET. The step d) hydrophobizing the fabric 2 causes a subsequent total hydrophobicization of the fabric 2, in particular in areas in which, during the melting process of the coating 11, the hydrophobic repelling agents were covered by the adhesives. This process step is equivalent to full sealing of the fabric 2 and ensures maximum protection against precipitation of air moisture or water droplets on the fabric so that it remains largely invisible even under adverse environmental conditions. Overall, it should be noted that the fabric 2 according to the insect screen according to the invention using the method according to the invention can be produced particularly efficiently.

LIST OF REFERENCE NUMBERS

1.

Insect screens

Second

tissue

Third

frame

4th

warp

5th

weft

6th

junction

7th

mesh

8th.

denier

9th

denier

10th

mesh

11th

coating

Claims (10)

1. Insect screen (1), comprising a frame (3) and a fabric (2) stretched by means of the frame (3), the fabric having a woven mesh structure (7), comprising warp threads (4) and weft threads (5) that are interconnected at node points (6) by means of adhesives, at least some of the warp threads (4) and/or weft threads (5) comprising a core, the core comprising a coating (11) which comprises thermally activatable adhesives for integrally bonding to itself or to other threads in the fabric (2), and the core having a higher melting point than the adhesive, characterised in that the coating (11) comprises hydrophobic repelling agents, and the fabric is hydrophobised.
2. Insect screen (1) according to claim 1, characterised in that the coating (11) comprises colourants.
3. Insect screen (1) according to either claim 1 or claim 2, characterised in that the core contains a polyester, in particular polyethylene terephthalate (PET), and/or the coating (11) contains a polyolefin, in particular polyethylene (PE), as an adhesive.
4. Insect screen (1) according to any of the preceding claims, characterised in that the coating (11) contains a fluorinated polyolefin, in particular polytetrafluoroethylene (PTFE), as a repelling agent.
5. Insect screen (1) according to claim 2, characterised in that the coating (11) contains carbon black as a colourant.
6. Insect screen (1) according to any of the preceding claims, characterised in that the thread (4, 5) is produced by means of coextrusion of the core and the coating (11).
7. Insect screen (1) according to any of the preceding claims, characterised in that adhesion promoters, in particular cyanoacrylate, are arranged between the core and the coating (11).
8. Insect screen (1) according to any of the preceding claims, characterised in that the core has a thickness of less than 0.20 mm, in particular equal to 0.15 mm.
9. Insect screen (1) according to any of preceding claims, characterised in that the fabric (2) has a mesh size (10) of 0.7 mm to 1.7 mm, in particular 1.1 mm.
10. Method for producing fabrics (2) for insect screens (1), comprising the steps of a) providing threads (4, 5) in the form of warp threads (4) and weft threads (5), at least some of the warp threads (4) and/or weft threads (5) comprising a core, the core comprising a coating (11) which comprises thermally activatable adhesives for integrally bonding to itself or to other threads in the fabric (2), the core having a higher melting point than the adhesive, and the coating (11) comprising hydrophobic repelling agents, b) weaving a fabric (2) using the warp threads (4) and weft threads (5) and c) heating the fabric (2) to a temperature that is higher than the melting point of the adhesive and lower than the melting point of the core, in order to produce integral bonds between the warp threads (4) and weft threads (5) at the node points (6) thereof, and d) hydrophobising the fabric (2).

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