Patent Application
20090053460
The invention relates to a method for producing a ductile tufted product, particularly a ductile tufted top carpet layer produced with it, particularly for the automotive interior area.
For the production of a tufted carpet, a method referred to as tufting is employed, which is to say a technique for producing three-dimensional surfaces, which operates based on the principle of a sewing machine.
During the process, tufting needles introduce a tuft yarn into a base material, referred to as the tufted backing. The tufting needles mounted to a needle bar are disposed in the width of the base material, for example a non-woven fabric, and simultaneously pierce the base material. Before the tufting needles return again upward into their starting position, the introduced tuft yarn is held on the bottom of the base material by hooks, referred to as loopers. In this way loops or pile, referred to as naps, are produced, which in the finished carped form the visible top (upper layer). Depending on the application, these loops can already be cut during the tufting process, using special blades. This produces the cut-pile carpets, which are used particularly in the automotive interior area, preferably at a percentage of over 95%.
It is the object of the invention to provide a method for producing a ductile tufted product, particularly an easily ductile tufted top carpet layer, wherein the method is as simple and economical as possible. The top carpet layer produced according to the method is supposed to be used particularly in the automotive interior area, or in the properties area. The term “properties area” shall encompass that the top carpet layer is designed particularly for high-traffic or extremely strained surfaces, particularly for offices, hotels, airports, hospitals, and the like.
This object is achieved by the characteristics of claim 1.
In the method, a melt-blown non-woven fabric is placed on a ductile polyester tufted backing, and the melt-blown non-woven fabric and the polyester tufted backing are tufted together. By applying the melt-blown non-woven fabric on the tufted backing synchronously with the tufting process, the method is particularly economical.
Due to the special combination of the material selection and the design of the method, the resulting tufted product, particularly as a top automobile carpet layer for applications in the interior automotive area, is characterized by particularly good ductility and accordingly high strength, elongation and tear propagation force data.
The dependent claims are advantageous refinements of the subject matter of the invention.
In a preferred embodiment of the method, the tufted product is introduced in the further carpet manufacturing process solely by a thermal treatment from the tufting piercing side, particularly without latex application.
In the tufting production, the latex represents a pretreatment of the raw product for a variety of methods for coating the backing or tufted backing. The latex is intended to lock the naps into the base material and/or the tufted backing. In this way, the desired integration of the naps is achieved, preventing the pulling of threads or fraying of the pile material. The latex material typically comprises synthetic latex with filler material.
By eliminating this latex application in the inventive production process, one step is eliminated. In addition, it is more compatible with the environment because during the production, recycling, and disposal processes the waste water is not polluted with latex residue, and because during the use of a tufted product treated in this way no emissions are formed by the latex application.
Consequently, the inventive method also satisfies the environmental stipulations and industrial standards, which have become more stringent, particularly in recent times.
Advantageously, for the method a polyester spun-bond non-woven is used as the polyester tufted backing, preferably having a basis weight of 70 g/m2 up to 140 g/m2, more preferred from 100 g/m2 to 120 g/m2.
Furthermore, in the method the melt-blown non-woven fabric having a basis weight of preferably 70 g/m2 up to 500 g/m2 is used, more preferred from 80 g/m2 to 200 g/m2, even more preferred from 80 g/m2 to 130 g/m2.
Due to the particularly low basis weights, the material consumption can be kept particularly low and the processing speed can be increased, allowing additional cost savings.
According to a preferred embodiment of the method, a thermoplastic raw material that can be spun or processed by injection molding is used as the raw material for the melt-blown non-woven fabric, particularly one selected from polyolefins, copolyolefins, polyesters, copolyesters, polyamides, and/or copolyamides having an MFI value (melt flow index) (according to DIN 1238 or ISO 1133) of 100 to 300 g/10 min.
Due to the low viscosity of the melt-blown raw material because of a high melt flow index, and the low viscosity of the melt-blown non-woven fabric that is produced, the penetration of the melted melt-blown non-woven wear layer in the tufted backing is favored. As a result, a three-dimensional composite layer is produced such that undesirable delamination between the wear layer and the tufted backing is prevented.
Preferably, a melt-blown non-woven fabric having a thickness of 0.5 mm to 1.5 mm is used, with 0.5 mm to 1.0 mm being particularly preferred.
The fiber titer of the melt-blown non-woven fabric is advantageously 0.06 dtex to 0.2 dtex, with 0.06 dtex to 0.1 dtex being preferred.
The bulky, soft melt-blown non-woven wear layer having a high specific fiber surface, lower fiber titer, and high fiber mobility facilitates the tufting without needle deviation and increases the number of contact points between the melt-blown non-woven wear layer and the fibers of the tufted backing, thus evenly strengthening the bond between the wear layer and the tufted backing across the cross-section.
The joint tufting of the melt-blown non-woven fabric and polyester tufted backing preferably occurs without prior needling or calendaring with a gauge of ⅛″ to 1/16″.
Alternatively, the melt-blown non-woven fabric is advantageously strengthened by an ultrasonic calendar having a bonding surface of less than 5%, preferably of less than 2%, and tufted together with the polyester tufted backing with a gauge of ⅛″ to 1/16″.
In a particularly preferred embodiment of the method, the melt-blown non-woven fabric and the polyester tufted backing are strengthened together by an ultrasonic calendar having a bonding surface of less than 5%, preferably of less than 2%, and tufted together with the polyester tufted backing with a gauge of ⅛″ to 1/16″.
Due to the joint strengthened, particularly good handling and better process stability than in the case of separate layers are guaranteed. Furthermore, the combination with the very small bonding surface at the same time allows sufficiently high fiber mobility, so that fiber damage during tufting can at least be reduced, thus increasing the quality of the tufted product, particularly with respect to ductility.
In a further carpet production process, preferably an acoustic non-woven material and/or at least one other insulating layer, for example a heavy layer having basis weights of, for example, 2 to 7 kg/m2 made of ethylene-vinyl acetate/ethylene-propylene-diene rubber, or coextruded film comprising polyethylene/polyamide (polyethylene), is applied to the tufting piercing side of the tufted product.
The tufted products produced according to the invention, at a tear propagation force in the longitudinal direction at room temperature (according to DIN 53859-3) of preferably 170 N to 240 N, have a particularly high tear propagation force value, and therefore particularly good ductility, so that these tufted products are particularly well suited for use as top carpet layers in the automotive interior area as automobile top carpet layers.
The ductile tufted products, particularly the ductile tufted automobile top carpet layers, at room temperature furthermore preferably have
a maximum tensile force in the longitudinal direction (according to EN 29073-3) of 250 N/5 cm to 400 N/5 cm, more preferred of 275 N/5 cm to 375 N/5 cm,
a maximum tensile force in the transverse direction (according to EN 29073-3) of 180 N/5 cm to 300 N/5 cm, more preferred of 203 N/5 cm to 250 N/5 cm,
a maximum tensile elongation in the longitudinal direction (according to EN 29073-3) of 45% to 60%, and
a maximum tensile elongation in the transverse direction (according to EN 29073-3) of 42% to 55%.
At 140° C., the ductile tufted products, particularly the ductile tufted automobile top carpet layers, advantageously have
a maximum tensile force in the longitudinal direction (according to EN 29073-3) of 185 N/5 cm to 200 N/5 cm,
a maximum tensile force in the transverse direction (according to EN 29073-3) of 85 N/5 cm to 120 N/5 cm,
a maximum tensile elongation in the longitudinal direction (according to EN 29073-3) of 65% to 70%, and
a maximum tensile elongation in the transverse direction (according to EN 29073-3) of 65% to 70%.
The subject matter of the invention will be explained in more detail based on an example.
As the raw material for the melt-blown non-woven fabric, polyethylene having a melt flow index (MFI) of 155 g/10 min according to DIN 1133 is used and spun through a melt-blowing spinneret. The polyethylene fibers obtained in this way have a fiber titer of 0.07 dtex.
Thereafter, the fibers are deposited in a suction drum, which has a distance of approximately 600 mm to the spinning nozzle, in order to produce a bulky and soft fibrous web, the fiber mobility of which is maintained in the tufting process.
The fibrous web weighing 80 g produced in this way can then optionally be strengthened by means of an ultrasonic calendar using light sonotrode pressing pressures of about 0.006 bar with a bonding surface of less than 5%, preferably of less than 2%, thus obtaining a still substantially bulky non-woven fabric. Alternatively, also light thermal strengthening using engraved or roughened calendaring rollers is conceivable.
The melt-blown non-woven fabric weighing 80 g produced according to the above-described method in the present case is placed on the tufted backing in non-strengthened form and strengthened only together with the tufted backing by means of an ultrasonic calendar using light sonotrode pressing pressures of about 0.006 bar with a bonding surface of about 1.6%. A polyester spun-bond non-woven material, Lutradur® LDT 5312 (Freudenberg), having a basis weight of 120 g/m2 is used as the tufted backing.
This composite made of melt-blown non-woven fabric and polyester tufted backing, the composite being slightly prestrengthened by means of ultrasound, is fed to the tufting loom infeed, wherein the melt-blown non-woven fabric side represents the needle or tufting piercing side.
The laboratory tufting loom has a needle working width of about 50 cm and a needle gauge of 1/10 inch (10 needles per 2.54 cm) pile quality.
The stitch density is about 56/10 cm. A BCF yarn, which is a bulked continuous filament, is used as the tuft yarn and has a polyamide 6 quality having a total strength of 1300 dtex and 128 individual filaments. Other conventional tuft yarns can likewise be used.
The tuft yarn weight is about 400 g/m2. The complete laboratory tufting arrangement produces, in the narrow width, a carpet design that is typically used in the automotive field (with the exception of the additionally inserted layer).
Before the tufting needles return again, the inserted tuft yarn is held by hooks such that loops or naps are produced. In this way, a loop pile carpet is produced. If the loops, as in this example, are cut with a blade, a cut-pile carpet is produced.
After the melt-blown non-woven fabric has been tufted together with the polyester tufted backing, thermal treatment is provided from the tufting piercing side until the polyethylene of the melt-blown non-woven fabric has melted. The top carpet layer produced in this way is analyzed for the following properties.
Properties of the Top Carpet Layer Produced in this way at Room Temperature:
maximum tensile force in the longitudinal direction (according to EN 29073-3): 368 N/5 cm
maximum tensile force in the transverse direction (according to EN 29073-3): 203 N/5 cm
maximum tensile elongation in the longitudinal direction (according to EN 29073-3): 58%
maximum tensile elongation in the transverse direction (according to EN 29073-3): 44%
tear propagation force in the longitudinal direction (according to DIN 53859-3): 218 N
The higher the values of the tear propagation force, the higher the ductility.
By comparison, the tear propagation force of the tufted backing alone (Lutradur® LDT 53 12, 120 g/m2), which is to say without the melt-blown non-woven fabric, is 198 N, and the tear propagation force of the tufted backing (Lutradur® LDT 5312, 120 g/m2) having a conventional latex or latex binder treatment (approx. 100 g/m2) is 150 N.
With a conventional latex treatment, ductility is consequently negatively influenced, while the tufted product manufactured according to the invention has a particularly high tear propagation force value and therefore particularly good ductility, so that this tufted product is particularly well-suited for use as a top carpet layer in the automotive interior area.
Properties of the Top Carpet Layer Produced in this way at 140° C.:
maximum tensile force in the longitudinal direction (according to EN 29073-3): 196 N/5 cm
maximum tensile force in the transverse direction (according to EN 29073-3): 111 N/5 cm
maximum tensile elongation in the longitudinal direction (according to EN 29073-3): 75%
maximum tensile elongation in the transverse direction (according to EN 29073-3): 69%
In addition to determining the force and elongation behaviors of the tufted product by means of measurements on a tensile elongation test machine, the ductility properties of the tufted product were determined using an internal measuring method. To this end, circular samples of the tufted product having a diameter of 24 cm are punched out, clamped in a clamping ring, and fixed by means of brass screws and threaded bolts. At the back, which is to say from the tufting piercing side, the fixed sample is heated by infrared heating to a defined temperature, in the present example to 140° C., wherein a constant distance of 16 cm to the infrared field is maintained.
After reaching the temperature, the clamping ring with the carpet sample fixed thereon is automatically placed on a displaceable hollow cylinder, which travels upward at a speed of 50 mm/s against a metal ball. The metal ball is cooled with water to 18° C. and has a diameter of 10 cm. In this process, the carpet sample is deformed from the tufting piercing side. The deformation depths that are measured are used to compute the deformation in percent.
The example of the top carpet layer produced according to the invention has the further advantage that it can be laminated with a heavy layer, without the additional application of polyethylene powder, which is common in the conventional carpet industry. Dispensing with this polyethylene powder application can be attributed to the fact that a bonding agent layer made of polyethylene is already provided on the carpet piercing side of the top carpet layer in the example.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2007 020 818.0 | May 2007 | DE | national |
