A METHOD TO MANUFACTURE A TEXTILE PRODUCT, A USE THEREOF, THE PRODUCT ITSELF, AND A DEVICE FOR APPLYING THE METHOD

Abstract

The present invention pertains to a method to manufacture a textile product, in particular a carpet product such as broadloom carpet, carpet tiles, mats and rugs, comprising a first sheet having polyamide yarns fastened to this sheet to form a pile thereon, the method comprising providing the sheet, stitching the polyamide yarns through the sheet to form the pile on a first surface of the sheet, the pile extending for a predetermined length from this first surface, and to form loops of the yarns at a second surface of the sheet, and fastening the yarns to the sheet by creating a layer of fused material on the second surface of the sheet using heat, wherein during creating the layer of fused material, at least the distal half of the length of the pile is maintained at a temperature at least 70 C. below the melting temperature of the polyamide. The invention also pertains to a method to use a textile product obtained with the new method and a device for applying the said method.

Claims

1. A method to manufacture a textile product comprising a first sheet having polyamide yarns fastened to this sheet to form a pile thereon, the method comprising: providing the sheet, stitching the polyamide yarns through the sheet to form the pile on a first surface of the sheet, the pile extending for a predetermined length from this first surface, and to form loops of the yarns at a second surface of the sheet, fastening the yarns to the sheet by creating a layer of fused material on the second surface of the sheet using heat, wherein during creating the layer of fused material, at least the distal half of the length of the pile is maintained at a temperature at least 70 C. below the melting temperature of the polyamide.

2. A method according to claim 1, wherein the distal half of the length of the pile is maintained at a temperature at least 100 C. below the melting temperature of the polyamide.

3. A method according to claim 1, wherein the at least distal half of the length of the pile is maintained at the temperature below the melting temperature of the polyamide using cooling means.

4. A method according to claim 1, wherein for fastening the yarns to the sheet, the second surface of the sheet is contacted with a surface of a hot body to at least partly melt the loops of the yarns to create the mass of molten material.

5. A method according to claim 4, wherein the surface of the hot body has a relative speed with respect to the second surface of the first sheet.

6. A method according to claim 5, wherein the surface of the hot body is stationary, whereas the first sheet is transported along the hot body.

7. A method according to claim 1, wherein the textile product is a laminate of the first sheet and a second sheet, wherein after the second surface of the first sheet has been processed, an adhesive is applied to this second surface to which adhesive the second sheet is adhered.

8. A method according to claim 7, wherein the adhesive is a hot melt adhesive.

9. A method according to claim 8, wherein the hot melt adhesive comprises at least 50% by weight of a polymer chosen from the group consisting of polyurethane, polycarbonate, polyester, polyamide, poly(ester-amide), polyolefine, mixtures thereof and/or copolymers thereof.

10. A method according to claim 7, wherein an intermediate layer is provided between the first sheet and the second sheet wherein the intermediate layer is resilient to allow local deformation of this layer along the second surface of the first sheet or along the surface of the second sheet adjacent to the intermediate layer.

11. A method according to claim 10, wherein the intermediate layer is a fibrous layer.

12. A method according to claim 11, wherein the intermediate layer is a non woven layer.

13. A method according to claim 12, wherein the intermediate layer is a knitted layer.

14. Use of a textile product obtainable according to claim 1 to cover a surface of a building or any other artificial or natural construction.

15. A textile product comprising a sheet having a top surface and a bottom surface, the textile product having polyamide yarns stitched through this sheet to form a pile on the surface of the sheet, the pile extending for a predetermined length from this first surface, the yarns being fastened to the bottom surface of the sheet by forming a layer of fused polyamide material on this bottom surface, wherein the yarns in the pile have a decreased amorphous content with respect to yarns of the same polyamide annealed at a temperature of about 43 C. below the melting temperature of the polymamide for 1 hour.

16. A device for use in manufacturing a textile product comprising a first sheet having polyamide yarns fastened to this sheet to form a pile thereon, the yarns being stitched through the sheet to form the pile on a first surface of the sheet, the pile extending for a predetermined length from this first surface, and loops of the yarns at a second surface of the sheet, the device comprising: heating means for heating the second surface of the sheet, means for creating a mass of fused material on the second surface of the sheet, and cooling means for cooling at least the distal half of the length of the pile to a temperature at least 70 C. below the melting temperature of the polyamide during creating the mass of fused material.

Description

EXAMPLES

[0031] FIG. 1 schematically shows a cross section of a textile product manufactured according to the invention

[0032] FIG. 2 schematically shows a configuration for applying a yarn melting process

[0033] FIG. 3 schematically shows details of an active cooling means

[0034] FIG. 4 schematically represents a laminating configuration

[0035] Example 1 provides process parameters for a method according to the invention

[0036] Example 2 is an example of a specific laminated textile product according to the invention

[0037] Example 3 provides a method to establish dirt retaining properties of carpet.

[0038] Example 4 provides a method to determine whether or not the textile product is a product according to the invention.

[0039] FIG. 1

[0040] FIG. 1 is a schematic representation of respective layers of an embodiment of a laminated textile product manufactured according to the invention, in this case a carpet tile. The tile comprises a first sheet 2, the so called primary backing, which may be a tufted nonwoven sealed polyester backing. The polyamide yarns 5 extend from the first surface 3 of this first sheet and are sealed to the second surface 4 of the sheet using the yarn melting method as described with reference to FIG. 2. The weight of this first sheet is typically about 500-800 g per m.sup.2. In order to provide mechanical stability, the tile 1 comprises a second sheet 6, in this case a polyester needle felt backing. The weight of this second sheet is typically about 700-900 g/m.sup.2. In between the first and second sheet is an optional resilient layer 10 (which could for example be a polyester expansion fleece having a weight of 330 g/m.sup.2, obtainable from TWE, Emsdetten, Germany as Abstandsvliesstof). The three layers (first and second sheet and intermediate layer) are laminated together using a glue, which may be a polyester hot melt glue as obtainable from DSM, Geleen, the Netherlands, applied as layers 11 and 12 at a weight of about 300 g/m.sup.2.

[0041] FIG. 2

[0042] FIG. 2 which schematically represents a configuration for applying a yarn melting process (also called a fibre-binding process) for use in the present invention. In the configuration shown in FIG. 2 a first heating block 500 and a second heating block 501 are present, in order to heat the heating elements, also denoted as heating blades or heating bodies, 505 and 506 respectively. These heating elements have a working surface 515 and 516 respectively, which surfaces are brought in contact with a product to be processed, typically a primary carrier to which yarns are applied via a stitching process such as tufting. The working surfaces both have a working width of 18 mm, and the intermediate distance is 26 mm. The back surface of the product is brought in contact with the working surfaces of the heating elements. In order to be able and apply adequate pressure for the product to be processed, an actively cooled Teflon support 520 is present which is used to counteract a pushing force applied to the heating elements and at the same time cool the polyamide pile yarns. In operation, the heating elements are moved relatively to the product as indicated by arrow X. Typically, the heating elements are stationary and the product is forced to travel between the working surfaces and the Teflon support in a direction indicated with X.

[0043] The (intermediate) textile product to be processed with the above described configuration (the product itself is not shown in FIG. 2) consists of a primary sheet provided with a cut pile of polyamide yarns, tufted into the sheet. The yarns consist almost 100% of PA6 and typically have a melting temperature of about 220 C. This product is processed using a temperature of the first heating element of 180-200 C., in order to pre-heat the product. The second heating element is kept at a temperature about 15 C. above the melting temperature of the polyamide yarns. To keep the temperatures at the required level, the heating blocks and heating elements are provided with layers of insulating material 510, 511, 512 and 513 respectively. The product is supplied at a speed of 12 mm per second (0.72 metre per minute) or higher, and the pressure applied with the heating elements is about 1.35 Newton per square centimetre. This way, the PA yarns are melted and form a layer of molten material on the second surface of the primary backing. By using the cooled Teflon plate, the temperature of the pile, at least the top half of this pile is kept at about 95 C. during this melting process. After the melting process, the molten layer is cooled down and forms a layer of fused PA material.

[0044] Downstream of the heating blocks, at both sides of the transport path 200 of the intermediate textile product to be processed, is a further active cooling means 300. In this embodiment, the means 300 comprise inverted domes 301 and 302. Through these domes, cold cooling air can be blown towards the textile product, in order to actively cool the heated surface of the textile product.

[0045] FIG. 3

[0046] FIG. 3 schematically shows details of another embodiment of the invention. In this embodiment, the heating bodies 505 and 506 are arranged around a circular support 520 which is actively cooled to a temperature of about 90 C. The intermediate textile product 2 is transported with its second surface 4 towards the heating bodies, while the product 2 is lying with its first surface on the rotating support drum 520. At the downstream side of the drum 520, the intermediate product is transported along transport path 200 and encounters active cooling means 300. In this embodiment, the cooling means is a Teflon coated aluminum stationary massive beam 305 having a thickness of 20 mm, kept at a temperature below the glass transition temperature of the polyester yarns, typically below 120 C. The beam has a length L.sub.1 of 80 mm in the transport direction, and is situated at a distance L.sub.2 of 76 mm from heating body 505. The beam is pressed against the second surface 4 of the textile product 2 to provide for an additional calendaring action. This way, the process may lead to a product having a smooth and glossy back surface at the sites where the stitched yarns extend from this back surface.

[0047] FIG. 4

[0048] FIG. 4 schematically represents a laminating configuration for applying a second sheet, in this case a dimensionally stable secondary backing sheet, to the back of the first sheet that is produced with a method as described in conjunction with FIG. 2. In this embodiment the term target sheet denotes either the separate resilient layer and second sheet applied one after the other in that order, or the combined laminate of them both applied together to the first sheet. Both the second sheet and the resilient layer may be of polyester. In this figure a first roller 600 is depicted on to which roller is wound a 2 metre wide web of the said (pre-fabricated) product made according to the method described in conjunction with FIG. 2. The product is unwound from the roller 600 to have its back-side 217 to come into contact with a second roller 601. This roller is provided to apply a layer of hot melt adhesive (HMA) 219 to the back side 217. For this, a bulk amount of HMA 219 is present and heated between the rollers 601 and 602. The thickness of this layer can be adjusted by adjusting the gap between these two rollers. Downstream of the site of HMA application is the target sheet 215, which sheet is unwound from roller 603. This sheet is pressed against the hot and tacky adhesive and cooled in the unit 700. This unit consists of two belts 701 and 702 which on the one hand press the target sheet 215 against the primary product, and on the other hand cools down the adhesive to below its solidification temperature. The resulting end product 201 (corresponding to textile product 1 of FIG. 1) is thereafter wound on roller 604. In an alternative embodiment the fibre-binding process as described in relation with FIG. 2 and the lamination process take place in line. In that case, the fibre-binding set-up as shown in FIG. 2 could be placed between roller 600 and roller 601. In this embodiment the applied HMA is the polyester of Example D as described in the Research Disclosure RD591084 as mentioned herein before. A suitable temperature of the roller 601 at the site where this HMA is applied to the back-side of the primary backing is 140 C. By having a gap of 2 mm, the HMA, at a web speed of 2 m/min, roller 602 not revolving and roller 601 having a circumferential speed of 1.6 m/min, will be applied with a thickness of about 500 g/m.sup.2. This is adequate to glue the target sheet 215 to the primary backing (i.e. the first sheet).

[0049] The hot melt adhesive may be optionally provided as a layer having a thickness of less than 1 mm, usefully less than 0.5 mm, more usefully from 0.2 to 0.4 mm. Whereas in the prior art carpets on the market, the hot melt layer typically has a thickness well above 1 mm, applicant found that when reducing the thickness of this layer to 1 mm or below an adequate adhesion can still be obtained. Therefore, the adhesive layer present in textile products of the present invention may have preferred mean thickness of from 50 microns to 1 mm, more preferably from 0.1 mm to 0.8 mm, most preferably from 0.2 mm to 0.4 mm. The amount of HMA used to form the adhesive layer in textile products of the present invention may be from 0.01 to 1000 g/m.sup.2 of HMA per area of the adhesive layer. In another embodiment the HMA may be applied in an amount of from 0.05 to 800 g/m.sup.2. In a still yet other embodiment HMA may be applied in an amount from 0.1 to 600 g/m.sup.2.

Example 1

[0050] Example 1 provides process parameters for a method according to the invention. In this example, the process parameters for a set up as depicted in FIG. 3 are given. The textile product is heated with heating body 505 to a temperate of 235 C. At the position where the product leaves the nip between heating element 505 and roller 520, the temperature of the top of the pile (as measured using an IR camera) is about 95 C. (about 125 C. below the melting point of PA). When the product arrives at the cooling beam, its temperature at the side bearing the layer of fused material is still around 160 C. The beam actively cools this hot surface very quickly, due to the intensive contact, to a temperature of about 100 C. at the end of the length L.sub.1 of the beam. This temperature is reached within 10 seconds after the second surface is heated with heating body 505.

Example 2

[0051] Example 2 is an example of a specific laminated textile product according to the invention. Reference numbers refer to parts corresponding to the textile product as shown in FIG. 1. The textile product of this example comprises a first sheet 2 (the primary backing), which is a 100% polyester non-woven having a weight of 120 g/m.sup.2 obtained from Freudenberg Vliesstoffe SE & Co. KG Neuenburg, Germany. This primary backing is tufted with a cut pile of 100% PA6 yarns (available from Aquafil (Cartersville, Ga., USA). The polyamide yarns 5 extend from the first surface 3 of the primary backing and are sealed to the second surface 4 of the primary backing using the fibre binding method as described with reference to FIG. 2. The total weight of this tufted sheet is about 700 g/m.sup.2. In order to provide mechanical stability, the textile product comprises a secondary backing (second sheet 6), in this case a backing of a polyester needle felt backing fleece obtained as Qualitex Nadelvlies from TWE, Emsdetten, Germany. The weight of this second sheet is about 900 g/m.sup.2. The layers are glued together using a polyester hot melt glue from DSM, Geleen, The Netherlands (available under the trade name Uralac), applied at a weight of about 300 g/m.sup.2 (which is the same amount as typically used for textile products having polyamide yarns tufted to the primary backing and processed with the same fibre binding method). The total weight of the carpet tile is thus about 1.9 kg/m.sup.2. The laminated textile product appears to be very durable and resistant against delamination.

Example 3

[0052] A piece of carpet made in accordance with example 2 was tested regarding its properties to retain dirt (or, to let go dirt). In this method a piece of carpet having dimensions of 180600 mm is firstly intensively contacted with dirt, by adding 15 grams of so called VNTF dirt (a standard type of dirt, a predetermined mixture of pigmented organic and inorganic solid materials, mineral oil, and quartz crystal sand, standardized by the Organisation of Dutch Carpet Producers; available from the TFI Institute in Aachen, Germany), and fixing the dirt in a Tetrapod machine (see Journal of the Textile Institute Transactions, Volume 56, Issue 3, 1965) during 800 rotations. After this, the carpet is cleaned in a standardised way using a machine as described in EP2198263 (titled A method for testing the impact of a cleaning process on a property of a fabric, an apparatus for use in such a method, and use of said method or apparatus for labelling a fabric), in particular with reference to FIGS. 1, 2 and 3 of this patent application. In this case a vacuum cleaner was used to collect the dirt. The amount of collected dirt was measured by weighing with an accuracy of 0.0001 gram. The experiment was done four times with pieces of carpet made according to example 2. As a control, the same type of carpet was used for the control experiments, albeit that the control carpet was previously annealed for 10 minutes in an oven at 170 C. This annealing step corresponds to a (minimal) annealing step when a carpet is made using a traditional technique where the carpet as a whole is heated in an oven to fix the secondary backing. In each experiment both carpet types were treated in the same tetrapod machine, and both pieces of carpet were cleaned in the same machine. The results of the amounts of dirt released by the carpets are indicated in Table 1 below.

TABLE-US-00001 TABLE 1 Amount of dirt extracted (grams) Experiment PA carpet, heat annealed PA carpet of the invention 1 4.1014 6.0891 2 5.4162 6.6511 3 6.1916 6.6508 4 6.1331 7.0993

[0053] From this experiment it can be concluded that a PA carpet made according to the invention has better dirt release properties than traditional carpet and therefore can be qualified as a low stain carpet.

Example 4

[0054] Example 4 provides a method to determine whether or not the textile product is a product according to the invention. In this method the polyamide material which is the same as the material used for the yarns in the textile product is subjected to an annealing temperature well below 180 C. This temperature is chosen since it is a typical temperature for any conventional backing oven used to fuse a secondary backing to a textile material and is about 43 C. below the melting temperature of a typical PA used for making carpet. The fact that the amorphous content of the material after 1 hour of annealing is below that of the same material annealed at 180 C., demonstrates that such a material processed according to the method of the invention will also lead to a product according to the invention.

[0055] Depicted in Table 2 are the results from the annealing experiment of PA6 material typically used for yarns of carpet products. The material is presented as non-fiber bonded fibers, and heated for 1 h at different temperatures as indicated. The lowest temperature is about 150 C. below the melting temperature of the polyamide. The middle-temperature is slightly over 70 C. below the melting temperature. With a differential scanning calorimeter device, the Tg (glass transition temperature) and Tm (melting temperature) of the material is measured after the heat treatment.

TABLE-US-00002 TABLE 2 Tg and Tm for PA6 material annealed at different temperatures. Temperature [ C.] Tg [ C.] Tm [ C.] 70 56.7 223.3 150 53.2 223.3 180 50.9 221.3

[0056] The measurements show that at 180 C. (about 43 C. below the melting temperature of the polyamide used), the Tg and Tm drop and thus that fibers are more amorphous, in line with theory. This means that the fibers, by staying at least 70 C. below the melting temperature of the polyamide, remain higher in crystallinity.