Patent Application
20110083792
The present invention relates to a process for preparing a velour carpet that has advantageous properties over velour carpets of the prior art.
The term “tufting” refers to a technology for the production of three-dimensional textile sheets. it is the process most frequently employed worldwide for preparing carpets.
Tufting works on the principle of a sewing machine. Needles insert the so-called pile yarn into a base material (woven or non-woven fabric), the so-called primary backing or support.
The needles stitch through the base material; before the needles are running back again, the inserted pile yarn is held by loopers. This produces loops (pile knots) on the top side of the tufting fabric.
In this way, a so-called loop-pile carpet is obtained. If the loops are cut open with a knife, a velour carpet (cut-pile carpet) is formed. Frequently, the knife is already attached to the looper, so that the holding and cutting of the pile is done in one operation.
In order to hold the stitched pile yarn tight, a secondary backing or latex layer must be applied. This process is referred to as lamination or integration.
In addition, a “simpler” method is known in the prior art, which produces similar carpets without a pile yarn inserted into the primary backing from outside. For velour forming, needles stitch through a fibrous web/Malifleece and draw fiber loops between the bristles of a brush belt lying under the fibrous web/Malifleece. The fibers carried along by the up and down movement of the needles are crossed and thereby bonded together. The needles employed may be needles having small barbs on their sides, so-called crown needles, or needles having fork-like ends, so-called fork needles.
After the needling process, the velour is separated from the running brush belt by a pair of rollers. The degree of densification is determined by the number of stitches per unit area, the penetration depth of the needles into the fibrous web/Malifleece and the fiber count.
When dual-layer coats (velour+wear layer) are prepared, the fabric is turned over after the first needle zone and needled with the wear layer in the second needling zone. This is followed by backside bonding of the fibers by means of a binder based on synthetic rubber or acrylate by different application methods. For latex-free integrations, binding fibers or thermoplastic dispersions are employed. In this case, the fiber linear densities are between 6.7 and 17 dtex.
As described above in the just mentioned “simpler” method, no additional pile yarn is inserted from outside into the substrate web, especially Malifleece, i.e., the primary backing. In this case, the shape of a velour carpet is obtained due to the fact that the needles carry individual fibers from the fibrous web, especially Malifleece, into the brush belt.
Although this process yields velour carpets similar to those prepared by the tufting method, the former have a somewhat worse property profile as compared to the latter. Namely, tufting velour carpets usually have a higher fiber density. A high fiber density is in turn considered an important quality feature of such velour carpets, because it results among others in better cleaning properties, an increased resistance against pressure load and a better abrasion resistance.
Therefore, it is an object of the present invention to improve the processes of the prior art, especially the “simpler” process as set forth above, for preparing velour carpets in such terms that a velour carpet having a higher fiber density than has been possible by the previously known prior art processes can be prepared.
In a first embodiment, the object of the invention is achieved by a process for preparing a velour carpet, comprising the following steps:
a) needling a web/Malifleece on a brush belt using a needling machine, a pile/support web being drawn into the brush belt and partially back again, so, that the fibers of the pile/support web are in the plane of the brush belt;
b) separating the web from the brush belt by means of a roller brush;
c) brushing up the pile side before the loops are cut open;
characterized in that a further web/Malifleece, especially a pile/support web, is applied to the back side of the web/Malifleece between steps a) and b), especially between a first and a second needling unit, to increase the fiber density and enhance the pile stability.
In a conventional (single-layer) dilour, the pile density can no longer be enhanced from a certain limit as the stitching density increases. This is prevented by two causes, namely the decrease of fiber mobility as the densification of the web increases, and the retrieval effect by multiple attacks on the same pile loops. According to the invention, the retrieval effect is avoided by applying the second web with a new supply of little densified and highly mobile fibers.
In the following, the various variants of the process according to the invention are further illustrated:
Reference variant 1:
On the one hand, step a) is to be understood in such terms that the pile/support web can be inserted into the brush belt (in accordance with the tufting method). However, alternatively and/or cumulatively, the fibers of the web/Malifleece may also represent the pile layer; thus, no separate pile yarn is introduced from outside in this case, but the fibers are drawn along with the needles into the brush belt (in accordance with the above described “simpler” method without a pile yarn).
After the needling, the web/Malifleece is separated from the brush belt not only in step b). In addition, additional fibers are eliminated from the web by means of brushes in step c). This achieves a defined fiber standing condition, and the web retains its support layer. Thus, for equal weights, the fiber density is 1.5 times to twice as high as with standard velour carpets. The use of binding fibers further enhances the fiber density.
In particular, it is advantageous in the above described process if steps b) and c) are performed simultaneously. All in all, this corresponds to the saving of a process step and is thus particularly favorable under aspects of process economy.
Further, it is preferred that the back side of the web is sprayed with water and/or a commercially available dispersion or bonded only by the use of binding fibers, and dried, especially without tension. This fixes the standing condition of the fibers, and the fiber density is again increased. At the same time, the fibers are integrated.
Further, it is preferred that the pile side of the web/Malifleece is brushed against the grain after step c) for erecting the fibers, and protruding fibers are shorn off. This again additionally fixes the standing condition of the fibers, and the surface of the velour carpet is clearly smoothed, which is important, in particular, for those applications in which the pile side is the visible side of the velour carpet.
Preferably, a web/Malifleece and/or a pile yarn is employed that comprises fibers of polypropylene (PP), polyester (PES), polyamide (PA) or mixtures thereof.
Depending on the application, the respective advantage of the fibers and/or fiber mixtures resides in the price, light fastness and abrasion resistance.
Further, a web/Malifleece and/or a pile/support web whose fibers have a yarn count within a range of from 3.3 to 11 dtex is preferably employed.
The respective advantage resides in the higher density for the same weights of fiber employed, the improved cleaning ability and an increase of the abrasion resistance.
In particular, it is preferred that a densified pile/support web is employed as the web/Malifleece, especially a web with a longitudinal/transversal strength ratio of 1.0/1.2 to 1.4.
It serves for a higher fiber transport during the needling process, and for better elongation properties in the deforming process.
Variant 2 according to the invention:
To increase the fiber density and enhance the pile stability, it is preferred that a further web/Malifleece, especially a pile/support web, is applied to the back side of the web/Malifleece before step a or between steps a) and b).
The use of such an additional pile/support web ultimately results in a fiber density that is about 2 to 3 times higher than that of standard velour carpets. The additional increase of the pile density and the use of the Malifleece causes an improved, i.e., reduced, abrasion, an increased resistance against pressure load and an increased cleaning ability.
The process according to the invention will be explained illustratively by means of
In
In
Two different velour carpet materials (referred to as variant I and variant II in the following; the latter was prepared using an additional pile/support web 9 as shown in
The following Table 1 compares the obtained velour carpet materials variant I and variant II with other materials of the prior art (tuft velour BCF and velour standard).
The arrows represent a comparison of the materials according to the invention with those of the prior art. Their meanings are (respectively based on similar pile weights):
equal
better
worse
As can be seen from this Table, the velour carpet materials prepared by the process according to the invention all have more favorable properties as compared to the materials of the prior art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2008 026 968.9 | Jun 2008 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2009/056503 | 5/28/2009 | WO | 00 | 12/2/2010 |
