Composite material with coating material

Abstract

A composite material includes a carrier material, wherein the carrier material is coated on a first surface with a first coating material and on a second surface with a second coating material, the composite material has links of coating material which run from the first surface of the carrier material to the second surface of the carrier material, and the links of coating material start from 1% to 90% of at least one of the surfaces of the carrier material. A method includes producing a composite material of this type.

Claims

1. A method for the continuous production of a composite material, comprising the process steps: furnishing a web-shaped carrier material in a melt roller calender arrangement, comprising at least a first coating calender; furnishing a first coating material and converting the first coating material into a molten state at a temperature above its softening temperature; producing a molten web of the first coating material; guiding the web of the first coating material still being in the molten state together with the web-shaped carrier material on a first surface of the carrier material through a nip of the first coating calender, whereby the first coating material is applied to the first surface of the carrier material and, due to a pressure exerted in the nip of the first coating calender, the first coating material and the carrier material undergo an integral connection; furnishing a second coating material and converting the second coating material into a molten state at a temperature above its softening temperature; producing a molten web of the second coating material; and guiding the web of the second coating material still being in the molten state together with the web-shaped carrier material on a second surface of the carrier material through a nip of a second coating calender, whereby the second coating material is applied to the second surface of the carrier material and, due to a pressure exerted in the nip of the second coating calender, the second coating material and the carrier material undergo an integral connection, wherein: the temperature of the first coating material and/or the second coating material and the pressure in the nip of the first and/or second coating calender are adjusted such that the first coating material and/or the second coating material flows from one surface of the carrier material to the other surface of the carrier material through the carrier material; links are thereby formed inside the carrier material and a starting area of the links is formed, which start from the first surface of the carrier material; and the starting area accounts for 1 to 90% of the area of the first surface measured at a penetration depth of 0.1 mm inside the carrier material.

2. The method for producing a composite material according to claim 1, wherein the web-shaped carrier material is fed in a width in a range of 0.5 to 3.5 m and coated over at least 95% of its width uniformly with the first and the second coating material.

3. The method for producing a composite material according to claim 1, wherein a linear pressure of at least 1.5 kN/mm is set in the nip of the first and/or in the nip of the second coating calender.

4. The method for producing a composite material according to claim 1, wherein: the first or second coating material with the web-shaped carrier material has a temperature that lies in a range of 20 to 150 C. above the softening temperature of the first or the second coating material; and the temperature at the same time is below a decomposition temperature of the first or the second coating material.

5. The method for producing a composite material according to claim 1, wherein: the first and/or second coating material is a polyolefin homopolymer or a polyolefin copolymer, and the temperature of the first or the second coating material during the calendering process is between 140 C. and 220 C.

6. The method for producing a composite material according to claim 1, wherein after the coating of the first and/or the second surface of the carrier material, the composite material is subjected to an embossing operation.

7. The method according to claim 6, wherein: a temperature during the embossing operation is 20 to 150 C. above the softening temperature of the first or the second coating material; and the temperature at the same time is below a decomposition temperature of the first or the second coating material.

8. The method according to claim 6, wherein: the embossing operation is carried out in an embossing calender; and a linear pressure of at least 1.5 kN/mm is adjusted in the nip of the embossing calender.

9. The method for producing a composite material according to claim 1, wherein the starting area accounts for 5% to 70% of the area of the first surface.

10. The method for producing a composite material according to claim 1, wherein the starting area accounts for 10% to 50% of the area of the first surface.

11. The method for producing a composite material according to claim 1, wherein the starting area accounts for 25% to 40% of the area of the first surface.

12. A method for the continuous production of a composite material, comprising the process steps: furnishing a web-shaped carrier material in a melt roller calender arrangement, comprising at least a coating calender; furnishing a first coating material and converting the first coating material into a molten state at a temperature above its softening temperature; producing a molten web of the first coating material; guiding the web of the first coating material still being in the molten state together with the web-shaped carrier material on a first surface of the carrier material through a nip of the coating calender, whereby the first coating material is applied to the first surface of the carrier material and, due to a pressure exerted in the nip of the coating calender, the first coating material and the carrier material undergo an integral connection; furnishing a second coating material and converting the second coating material into a molten state at a temperature above its softening temperature; producing a molten web of the second coating material; and guiding the web of the second coating material still being in the molten state together with the web-shaped carrier material on a second surface of the carrier material through a nip of the coating calender, whereby the second coating material is applied to the second surface of the carrier material and, due to a pressure exerted in the nip of the coating calender, the second coating material and the carrier material undergo an integral connection, wherein: the temperature of the first coating material and/or the second coating material and the pressure in the nip of the coating calender are adjusted such that the first coating material and/or the second coating material flows from one surface of the carrier material to the other surface of the carrier material through the carrier material; links are thereby formed inside the carrier material and a starting area of the links is formed, which start from the first surface of the carrier material; the starting area accounts for 1 to 90% of the area of the first surface measured at a penetration depth of 0.1 mm inside the carrier material.

13. The method for the continuous production of a composite material according to claim 12, wherein the starting area accounts for 5% to 70% of the area of the first surface.

14. The method for the continuous production of a composite material according to claim 12, wherein the starting area accounts for 10% to 50% of the area of the first surface.

15. The method for the continuous production of a composite material according to claim 12, wherein the starting area accounts for 25% to 40% of the area of the first surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in more detail below based on the examples and figures.

(2) FIG. 1 Shows diagrammatically a composite material with two coating sides.

(3) FIG. 2 Shows diagrammatically a woven fabric as a carrier material.

(4) FIG. 3 Shows diagrammatically a composite material.

(5) FIG. 4 Shows a microscope image of a section of a carrier material coated on one side.

(6) FIG. 5 Shows a microscope image of a section of a carrier material coated on one side.

(7) FIG. 6 Shows a microscope image of a section of a carrier material coated on one side in side view.

(8) FIG. 7 Shows a microscope image of a section of a carrier material coated on one side in side view.

DETAILED DESCRIPTION

(9) FIG. 1 shows diagrammatically a composite material 1, which in the example of FIG. 1 is composed of a first coating material 2, a second coating layer 2 of second coating material and a carrier material 3. The first coating layer 2 is connected via a link 4 to the second coating layer 2. The link 4 is composed of the first and/or the second coating material and runs through the carrier material 3. The first and the second coating layer 2, 2 form a first and second surface of the composite material 1. 1 to 90% of the first and/or the second surface of the composite material have links 4, which preferably run from the first surface to the second surface of the carrier material 3. Preferably, at least 20% and up to 100% of these links 4 run from the first surface to the second surface, so that the two surfaces are connected to one another by the links 4, as also shown in FIG. 1. Particularly preferably, at least 50% and up to 70% and very particularly preferably at least 80% and up to 90% of the links 4 run from the first surface up to the second surface so that a continuous connection between the first coating material 2 and the second coating material 2 is produced.

(10) FIG. 2 shows a woven fabric 3 as carrier material 3. The woven fabric 3 has warp threads 8 and weft threads 9 in a linen weave. Between the intersection points of the warp threads and weft threads the woven fabric 3 has openings 5, which are regularly or uniformly distributed over the surface of the fabric and depend in their frequency from the type of weave and the number of threads per centimeter. In the production of the composite material, for example, a fabric 3 as shown in FIG. 2, is coated with a melt roller calandering firstly on the first surface and subsequently on the second surface of the fabric 3 as carrier material 3 with a first and a second coating material so that a first coating layer 2 and a second coating layer 2 are formed. Already with the melt roller calandering (or also only with a calandering) the first and/or the second coating material reaches the openings 5, so that links 4 are embodied. When starting from each top side of the carrier material 3, coating material in the form of melt reaches the openings 5 during the calandering, either a continuous link 4as shown in FIG. 1is formed or two links are formed, which extend from each top side of the fabric 3 into the fabric 3. The formation of continuous links 4 is preferred. The coated fabric 3 can be subjected to an embossing operation preferably after the coating on both sides. With this embossing operation, the coated fabric 3 is, e.g., again heated so that the links of coating material and the coating layer 2 at least in part melt again. Under pressure, the coating material is then again pressed into the fabric 3 as carrier material. Instead of an embossing operation after a new melting of course it is also possible that after the coating on both sides the composite material directly after leaving the coating calander and before cooling of the composite material is subjected to an embossing operation. Since the links 4 in the interior of the carrier material 3 are likewise melted at least in part, the coating materials of the first top side of the carrier material and the second top side of the carrier material mix in the interior of the links 4. Therefore even if during the calandering only links 4 are formed which do not extend to the opposite top side of the carrier material 3, through a subsequent embossing operation the formation of continuous links 4, as shown in FIG. 1, but at least a greater partial encasing of e.g. yarns of the carrier material can be achieved.

(11) FIG. 3 shows diagrammatically the layer structure of a composite material 1 graphically. The composite material 1 has in the example as a core a woven fabric 3 as carrier material 3. The carrier material 3 is coated on both sides. On a first top side, the carrier material 3 therefore has a full-surface coating layer 2 of a first coating material. On a second top side of the carrier material 3, the carrier material 3 has a full-surface coating layer 2 of a second coating material. The first and the second coating layer 2, 2 optionally have respectively a protective layer 6 and 7. The protective layers 6, 7 can be, for example, varnish layers which are designed to protect the composite material 1 from dirt, moisture and/or insecticidal attack or fungal attack. The first coating layer 2 and the second coating layer 2 can be made from the same coating material. Likewise, the first protective layer 7 and the second protective layer 6 can also be of the same protective material. The composite material 1 can be used, for example, for textile architecture, textile building, for food containers, use containers, roofing and as material in the aerospace industry.

(12) FIG. 4 and FIG. 5 respectively show an optical microscope image of a carrier material 3 coated on one side after the application of the first coating material. The images show the still uncoated side of the carrier material 3. Between the warp threads 8 and the weft threads 9 of the carrier material 3 (in the example a woven fabric) openings 5 are discernible, which are filled with coating material, wherein the coating material in part also penetrates into the spaces between the warp threads 8 and the weft threads 9 of the woven fabric and ensure a partial enveloping of the threads. The coating material penetrating the openings 5 forms a link 4, wherein the link 4 extends from the coating layer of the first surface of the carrier material 3 lying behind the observation plane up to the not yet coated second surface of the carrier material 3 shown. The coating material in the opening 5, which forms the link, lies in this case approximately in the same plane as the surfaces of the warp threads 8 and the weft threads 9 in the surface side of the carrier material 3 shown. In a subsequent coating of the second surface of the carrier material 3 (which cannot be seen) the coating material links 4 can then come into contact with links 4 starting from the coating of the second surface of the carrier material 3, and the coating material of the first surface of the carrier material can thus form the continuous links 4 with the coating material of the second surface, for example, by melting, intermixing or mixing.

(13) FIGS. 6 and 7 respectively show a side view of a carrier material 3 coated on one side. A coating layer 2 of coating material has been applied on a (second) surface of the carrier material 3 essentially over the entire surface by means of a melt roller calander. The coating material has thereby been pressed into openings 5 of the carrier material 3 during the coating operation so that this coating material reaches through the carrier material 3 to the (first) surface of the carrier material 3. The coating material that has passed though the carrier material 3 forms a link 4 inside the carrier material 3. In FIGS. 6 and 7 the coating material has essentially been pressed completely through the carrier material during the coating 1. Pressed through means in this context that the coating material is pressed essentially perpendicular to the main extension plane of the coating layer through the carrier material 3 in the direction of the other surface of the carrier material 3. In contrast to FIGS. 6 and 7, the coating material however can also be pressed only half or three quarters through the carrier material 3. Of course, in a coating operation the coating material can also be pressed at various points of the carrier material 3 also at different depths thereinto. For example, 80% of the links 4 can be pressed essentially completely through the carrier material 3 and 20% of the links 4 half way through the carrier material 3. in another example at least 60%, preferably at least 80% and very particularly preferably at least 90% of these links 4 can be pressed essentially completely through the carrier material 3.

(14) Preferably, the carrier material is composed of a woven fabric of a high-tenacity polyethylene yarn (e.g., Dyneema from DSM B.V.) and the first and/or the second coating material is preferably made from a metallocene plastomer. Through the links of coating material, which run inside the carrier material, the cited fabric can be advantageously kept stable in length and width, because a crimping of the fabric is avoided due to the links. Furthermore advantageously, the fabric of high-tenacity polyethylene yarn can be easily coated due to the presence of the links, since the links engage in the carrier material or the two coating layers are connected by the links to one another and the carrier material is sandwiched. With a curtain, for example, which was woven from high-tenacity polyethylene yarn and which was coated with a polyolefin such as, e.g., the above mentioned low-density polyethylene copolymers produced by means of metallocene catalysts, the curtain, even after the curtain has been used several times (for example, moving the curtain to release an opening and closing it again), the same length of the curtain and the same width of the curtain can be measured.

Example 1

(15) A fabric web with a width of 3.2 m was furnished as a carrier material. The fabric was a polyester fabric (PES fabric) with an open linen weave in the form of an open lattice construction and a fabric construction of 4.3/4.3 thread/cm. The yarns (Diolen, Polyester High Performance) forming the thread had a thread count of 1100 dtex and a yarn twist of Z60/60. The fabric had a weight per unit area of 108 g/m.sup.2.

(16) A polypropylene (Hilfax, type CA 10A, Basell) was used as a coating material with which the PES fabric was coated. Both surfaces of the fabric were coated with this coating material.

(17) For preheating, the fabric web was preheated over several heated rollers (T=120 C.) and subsequently continuously guided between the rollers of a coating calander and there coated with the coating material. The coating material in the molten state at a temperature of 185 C. on the side of the first surface of the fabric was thereby conveyed via an extruder into the nip of the coating calander and there shaped to form a web. The rollers of the calander were heated to a temperature of 145 C. or 165 C. The linear pressure in the nip of the coating calander was set to approx. 3.5 kN/mm. While running the fabric and coating material through the nip of the coating calander, the fabric was coated on its first surface with the web of the polypropylene coating material, wherein at the same time the coating material was pressed into the fabric structure. The coating layers had in each case a weight per unit area of 545 g/m.sup.2, so that a total weight of the resulting composite material of approx. 1200 g/m.sup.2 resulted.

(18) After the cooling of the carrier material coated on one side, this was again fed to the process and coated on its second side with the PP coating material while being guided through the nip of the coating calander according to the method described above. The coating layers had in each case a weight per unit area of 545 g/m.sup.2 so that a total weight of the resulting composite material of approx. 1200 g/m.sup.2 resulted.

(19) Subsequently, the fabric coated on both sides was subjected to an embossing operation. To this end, the coated fabric was guided through the nip of an embossing calander under a linear pressure of approx. 2.3 kN/mm, the rollers of which had a temperature of approx. 150 C. An improvement of the bond was achieved through the embossing operation following the coating operation.

(20) To judge the quality of the connection between the carrier material and coating, the adhesive strength of the composite material was tested. The composite material obtained after coating in the coating calander and embossing in the embossing calander had a high adhesive strength that was greater than 25 N/cm.

Example 2

(21) The procedure was as in Example 1. Deviating from Example 1, a polyester fabric with a width of 80 cm and a weight per unit area of 188 g/m.sup.2 was used as carrier material. The web of this fabric was preheated to 70 C. over several heated rollers and continuously fed to the coating calander.

(22) A polyethylene copolymerisate (Exact Plastomer 8210, Dexplastomers) was used as coating material, which contained flame retardant as an additive. The coating material was fed into the nip of the coating calander at a temperature of 155 C., shaped to form a web there and respectively one of the surfaces of the PES fabric was coated therewith. The rollers of the coating calander had a temperature of 170 C. or 180 C. The linear pressure in the nip of the coating calander during the application of the coating to the first side of the carrier material was 2.8 kN/mm and during the application of the coating on the second side of the carrier material 5.5 kN/mm. The coating layers had a weight per unit area of 272 g/m.sup.2 and of 220 g/m.sup.2 so that a total weight of the resulting composite material of approx. 680 g/m.sup.2 resulted.

(23) Following the coating, the coated carrier material was subjected to an embossing operation. To this end, the coated fabric was guided through an embossing calander under a linear pressure of 5.5 kN/mm, the rollers of which had a temperature of approx. 170 C.

(24) The composite material obtained after coating in the coating calander and embossing in the embossing calander had an adhesive strength of more than 25 N/cm.

Example 3

(25) The procedure was as in Example 1. Deviating from Example 1, a fabric of high-tenacity polyethylene yarns (type Dyneema SK65, DSM Dyneema B.V.) was used as a carrier material with a P2/2 basket weave, a fabric construction of 6.0/6.0 thread/cm and a weight per unit area of 105 g/m.sup.2. The fabric had a width of 80 cm. The polyethylene yarns had a thread count of 880 dtex and a yarn twist of 100S/100S. The web of this fabric was preheated via several heated rollers to 40 C. and continuously fed to the coating calander.

(26) As a coating material the polyethylene copolymerisate from Example 3 was used (Exact Plastomer 8210, Dexplastomers), which was provided with a flame retardant. The coating material was fed into the nip of the coating calander at a temperature of 180 C., shaped there to form a web and s respectively one of the surfaces of the PES fabric was coated therewith. The rollers of the coating calander were heated to a temperature of 170 C. or 180 C. The linear pressure in the nip of the coating calander during the application on the first side of the carrier material was 3.2 kN/mm and during the application on the second side of the carrier material was 5.5 kN/mm. The coating layers had a weight per unit area of 395 g/m.sup.2 and of 400 g/m.sup.2 so that a total weight of the resulting composite material of 900 g/m.sup.2 resulted.

(27) The coating was followed by an embossing operation in which the coated carrier material was guided through an embossing calander under pressure and at increased temperature. The linear pressure in the embossing calendar was 5.5 kN/mm the rollers of the embossing calander had a temperature of approx. 170 C.

(28) The composite material obtained after coating in the coating calander and embossing in the embossing calander had an adhesive strength of more than 25 N/cm.

Example 4

(29) The procedure was as in Example 3. Deviating from Example 4, as carrier material a fabric of high-tenacity polyethylene yarns (type Dyneema SK65, DSM Dyneema B.V.) with a width of 80 cm and a weight per unit area of 193 g/m.sup.2 was used. The web of this fabric was preheated to 90 C. over several heated rollers and continuously fed to the coating calander.

(30) As coating material the polyethylene copolymerisate Exact Plastomer 0203 (Dexplastomers) was used, which likewise was provided with a flame retardant. The coating material was fed into the nip of the coating calander at a temperature of 155 C., there shaped to form a web and respectively one of the surfaces of the PES fabric was coated therewith. The rollers of the coating calander were heated to a temperature of 117 C. or 127 C. The linear pressure in the nip of the coating calander was approx. 3.2 kN/mm. The coating layers had a weight per unit area of 150 g/m.sup.2 and of 187 g/m.sup.2 so that a total weight of the resulting composite material of 530 g/m.sup.2 resulted.

(31) The coating was followed by an embossing operation in which the coated carrier material was guided through an embossing calander under pressure and at increased temperature. The pressure in the embossing calander was also approx. 3.2 kN/mm, the rollers of the embossing calander had a temperature of approx. 120 C. The composite material obtained after the coating in the coating calander and embossing in the embossing calander had an adhesive strength of approx. 20 N/cm.

REFERENCE NUMBERS

(32) 1 Composite material 2 First coating layer 2 Second coating layer 3 Carrier material 4 Link 5 Opening 6 Second protective layer 7 First protective layer 8 Warp threads of the carrier material 3 9 Weft threads of the carrier material 3