Patent Application
20130302556
The invention relates to the field of carpets, and more specifically to the manufacture of carpets or carpet tiles. In particular, the invention relates to a method of manufacturing a (broadloom) carpet or carpet tile, and to a carpet or carpet tile obtained by performing the manufacturing method according to the invention.
In the manufacture of a carpet or a carpet tile, traditionally yarns are tufted in a support material, which support material is sheet-shaped, and may also be referred to as a primary backing. The tufting results in an intermediate product of the support material having yarns tufted therein. The tuft yarns may be anchored to the support material by applying a pre-coating at one side of the intermediate product, before further manufacturing steps are taken, such as one or more of providing secondary backing materials, calendering operations and the like.
A pre-coating, which may be a latex-based material, an adhesive, a hot melt adhesive, or any other adhesive agent, is applied in a fluid state. Consequently, the pre-coating must be dried by a heat treatment before a further manufacturing step is carried out. The heat treatment takes time and requires the supply of heating energy, and leads to solvents to escape from the adhesive agent.
Most carpet manufacturers nowadays seek for alternatives for certain stages in their production process to reach less environmental impact of the manufacturing process, and/or to enable a so-called cradle-to-cradle use concept of the carpet. In a manufacturing process implementing such principles, an alternative way of anchoring tufts to the support material may be applied.
NL1034840C discloses to thermally fuse tuft yarns to the support material to avoid using any pre-coating. A thermal fusion process requires high temperatures at the short contact times available for the fusion, where a hot contact element, such as a roller, briefly contacts the intermediate product at one side, as known e.g. from NL1026245C. Typically, temperatures of more than 240° C. of the contact element, and a predetermined contact time between the intermediate product and the contact element, are necessary to fuse tuft yarns to one another and/or to the support material.
A problem which is addressed in the reference NL1034840 is the dimensional stability of the end product when applying a fusing process instead of a pre-coating to anchor yarns in the intermediate product. The support material may deform as a consequence of the thermal fusing process such that absolute dimensions cannot be reproduced reliably, and the required flatness of the carpet cannot be reached. According to the reference NL1034840 this problem is solved by selecting a support material made from tapes, which are either alternatively made from polypropylene, and non-melting or high temperature melting natural or synthetic fibers or tapes, or which each consist of a combination of polypropylene tapes and non-melting or high temperature melting fibers or tapes.
This, however, in practice appears not to solve problems which appear at the edges of the carpet due to the very discontinuous nature of a tape fabric as a support material. Using a tape fabric leads to dimensional and shape instability at the edges of the carpet, and as a result transitions between different carpets cannot be produced with acceptable quality, that is with each edge being flat and straight. Such a problem is even greater in case carpet tiles are produced, since the total length of edges in a unit area of carpet tiles is much greater than in the same unit area of broadloom carpet.
Accordingly, a need exits for an improved manufacturing process involving carpet tuft thermal fusion to overcome the problems in the prior art, and to produce a carpet having satisfactory dimensional stability, such as at the edges of the carpet or carpet tiles.
It would be desirable to provide a carpet manufacturing method whereby a carpet or a carpet tile with required dimensional stability, including dimensional stability at the edges of the carpet or carpet tiles, can be obtained. Such requirements are e.g. defined in standards EN 986 ISO 2551 and DIN 54318. It would also be desirable to provide a carpet manufacturing method whereby a carpet or a carpet tile can be obtained with reduced environmental impact.
To better address one or more of these concerns, in a first aspect of the invention a method of manufacturing a carpet, such as a carpet tile, is provided. The method comprises providing an intermediate product comprising a support material having yarns tufted therein, the intermediate product having two opposite sides, and fusing the yarns at one of the sides of the intermediate product, for anchoring the tufted yarns to the support material. The support material comprises a first layer of a non-woven material, provided with a reinforcement.
The method according to the invention provides a satisfactory dimensional stability of the end product by reinforcing a non-woven material of the support material.
In particular, the reinforced support material appears to be able to cope with mechanical stresses in the intermediate product introduced by thermally fusing the yarns at one side of the intermediate product, such that the dimensional requirements of the applicable standards can be met, also at the edges of the carpet or carpet tile.
In an embodiment, the support material consists of a non-woven material and a reinforcement. Here, other materials than non-woven material and reinforcement materials or structures are excluded in the support material.
In an embodiment, the support material comprises one or more layers of non-woven material.
In an embodiment, the support material does not include a woven material, i.e. a material including parallel elongated elements, such as threads or bands or tapes, in different directions, and lying closely together, where a distance between two adjacent parallel elements is less than a width or thickness or diameter of an element. Such a woven material would disadvantageously give rise to dimensional and shape instability at the edges of the carpet or carpet tile.
In an embodiment, the reinforcement comprises a reinforcement layer, which may comprise a scrim or a fleece. In an embodiment, the support material comprises one or more layers of scrim.
Herein, a scrim is defined as a sheet comprising at least a plurality of parallel, spaced threads in a first direction, and a plurality of parallel, spaced threads in a second direction different from the first direction, the threads in the first direction thereby crossing the threads in the second direction, and being adhered to the threads in the second direction at the points of contact between the threads in the first direction and the threads in the second direction. As an example, an angle between the threads in the first direction and the threads in the second direction may be about ninety degrees. A distance between two adjacent threads in a scrim is greater than, in particular substantially greater than, more in particular at least two times, more in particular at least four times a width or thickness or diameter of the threads.
In an embodiment, the scrim is a woven scrim, with each thread of one direction directed alternatively over and under subsequent threads of the other direction. The connection between threads of different directions this provides, will lead to superior mechanical properties in different directions in the plane of the support material, and thus to an optimum dimensional stability of the carpet end product. However, as an acceptable alternative, the scrim may also be unwoven, where a layer of parallel, spaced threads in a first direction is positioned on a layer of parallel, spaced threads in a second direction.
In an embodiment, the reinforcement comprises separate parallel reinforcement threads, which will provide an appropriate reinforcement when the thermal fusing process would induce unacceptable shape or dimensional instability in one direction. When the threads are oriented in this direction, this instability can be prevented. A distance between two adjacent threads is greater than, in particular substantially greater than, more in particular at least two times, more in particular at least four times a width or thickness or diameter of the threads.
The reinforced support material can be supplied, and used as a base material in a (possibly part of a) production line for performing (possibly part of) the method according to the invention, but it is also conceivable to produce the reinforced support material in (possibly part of) a production line by starting with a non-woven sheet which is separate from a reinforcement, such as a scrim sheet, a fleece, or reinforcement threads, and providing the non-woven sheet with the reinforcement in the production line before a tufting step is carried out.
In an embodiment, the reinforcement is glued to the first layer. In a glueing process, a minimum amount of an adhesive may be used when the adhesive is applied to the scrim fibers only, and subsequently the scrim is brought into contact with, or pressed onto, the non-woven to produce the layered support material. The glue may be e.g. a latex or a hot melt.
In another embodiment, the reinforcement is adhered to the first layer by a fusing process, such as thermally fusing. Such fusing process avoids the use of an adhesive, which may simplify the support layer production process. In a thermal fusing process, heat is applied in a direct contact with a heating element, or by heat radiation.
Where reinforcing threads are used, they may be woven into the first layer of non-woven material of the support material.
In different embodiments, various combinations of materials of the non-woven and the scrim can be made. Each one of the non-woven and the scrim may be comprise polyester, PES, polypropylene, PP, glass, and/or polyamide, PA, in particular PA6 and/or PA6.6.
In an embodiment, the first (non-woven) layer of the support material is at a pile side of the intermediate product, and the reinforcement layer of the support material is at the opposite side of the intermediate product. In such arrangement, a risk of disengaging the reinforcement layer locally from the non-woven by the tufting process, wherein yarns are stitched from said opposite side to said pile side, is minimized.
In an embodiment, the step of fusing the yarns comprises thermally fusing the yarns. A thermal fusing process has low impact on the environment, and does not leave any additional substances or materials in the carpet during the production process.
In a thermal fusing process, the step of fusing the yarns is carried out by contacting the yarns with a hot contact element. The yarn parts that are contacted by the hot contact element, at least partly melt, and thereby adhere to adjacent yarn parts and/or the support material, thereby anchoring the yarns to the support material.
In an embodiment, the hot contact element is a roller, and the step of fusing the yarns is carried out by guiding the intermediate product along a surface of the roller. The intermediate product will contact part of the surface of the roller at any one time, which part can be optimized in area in view of the contact time required for the fusing process. The roller may be stationary, or may e.g. rotate to have a surface speed which is equal to, or about equal to the surface speed of the intermediate product. Other differences of surface speeds between the intermediate product and the roller surface are conceivable too, which differences are adapted to control a transfer of heat from the roller to the intermediate product.
In an embodiment of the method particularly, but not exclusively, intended for manufacturing carpet tiles, the step of applying one or more backing materials comprises applying a bitumen layer and/or a latex layer.
In a second aspect of the invention, a carpet, such as a carpet tile, is provided. The carpet comprises a support material with yarns tufted therein, the yarns being fused at one side of the tufted support material. The support material comprises a first layer of a non-woven material, provided with a reinforcement, as explained above.
In a third aspect of the invention, a support material for use in the method, or in the carpet of the invention is provided. The support material comprises a first layer of a non-woven material, provided with a reinforcement, as explained above.
These and other aspects of the invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like parts.
A sheet of a support material 2 is conveyed in the direction indicated by arrow 4, in a production region S.
In a production region T, yarns 6 are tufted in the support material 2. The tufting process employed may be any conventional or novel tufting process, resulting in an intermediate product having a pile side 8 and a non-pile side 10.
Next, the tufted yarns 6 are to be anchored to the support material 2 in a production region F. In the embodiment of the method shown in
The contact element or roller 12 has a heated surface, e.g. heated by heating elements (not shown in detail) provided inside the roller 12. The temperature of the surface may be in the range of 240-280° C. The intermediate product contacts the roller 12 along a predetermined part of its circumferential surface, which leads to a predetermined contact time between any part of the non-pile side 10 of the intermediate product and the surface of the roller 12, determined by the speed of conveyance of the support material 2 or the intermediate product. During the time of contact, heat is transferred to the non-pile side 10 of the intermediate product, whereby yarns 6 fuse with adjacent yarns 6 and/or with the supporting material 2. The pile side 8 of the intermediate product is not affected by the fusing process, and will be a user contacted surface of the finished carpet or carpet tile.
Instead of, or in addition to the heating by the roller 12, a heat radiator 13 may be provided at the non-pile side 10 of the intermediate product to fuse the yarns 6 with adjacent yarns 6 and/or with the support material 2.
Next, in a production region B, secondary backing materials are applied to the intermediate product after the fusing process. A backing material 16 like latex or bitumen or any other material providing mass or other required or desired property to the carpet, is applied at the side (in the embodiment: the non-pile side 10) of the intermediate product where the yarns have been fused. One or more further backing materials may be applied, such as a finishing material 18.
It is noted that in the above a method has been described to fuse yarns 6 and/or yarns and supporting material 2 at the non-pile side 10 of the intermediate product. However, alternatively the pile side 8 of the intermediate product may be brought into contact with the heated surface of the roller 12, thereby fusing the yarns 6 with adjacent yarns 6 and/or with the supporting material 2 at the pile side 8. In this alternative process, the non-pile side of the intermediate product is not affected by the fusing process, and will be a user contacted surface of the finished carpet or carpet tile. This user contacted surface may have the appearance of a woven carpet. Also in this alternative process, secondary backing materials, like backing material 16 and finishing material 18, will be applied to the pile side 8 of the intermediate product, i.e. the same side as the side where the fusing takes place.
From another perspective, the support material 2 is a layered material having a first layer of a non-woven material 20, and a second layer of a scrim 22. In practice, the support material 2 may comprise more than one layer of non-woven material 20, e.g. a sandwiched structure of a first non-woven material, a scrim, and a second non-woven material. The support material 2 may also comprise more than one layer of scrim 22, e.g. a sandwiched structure of a first scrim, a non-woven material, and a second scrim.
In an embodiment, the scrim may be a 1,100 dTex (grams per 10,000 meters) scrim having 2.8×2.8 threads per cm. The scrim may be a polyester scrim.
The scrim 22 may be adhered to the non-woven material 20 by applying an adhesive to the scrim 22 and/or the non-woven 20 and contacting them, e.g. pressing them together, and possibly applying heat for curing the adhesive. The adhesive may be a latex, or a hot melt. The scrim 22 is illustrated in
Separate threads, or the threads of a scrim 20 may be woven through the non-woven material 20, such that parts of the threads lie at one side of the non-woven material 20, and other parts of the threads lie at the opposite side of the non-woven material 20.
It is noted that in
In production region S, which may be part of a carpet production line, or be a production region separate from other production regions, the non-woven 20 and a reinforcement may be joined.
In the above, a carpet, such as a carpet tile, and its manufacturing method have been described. The carpet or carpet tile comprises a support material with yarns tufted therein. The support material comprises a first layer of a non-woven material, provided with a reinforcement. The yarns are thermally fused at one side of the tufted support material. One or more backing materials are applied to said one side of the tufted support material.
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention.
The terms “a” or “an”, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the claims or the invention.
The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005608 | Nov 2010 | NL | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/NL11/50742 | 11/1/2011 | WO | 00 | 7/17/2013 |
