EP0784108A1 - Size-free tangled multifilament yarn and method for its production - Google Patents

Abstract

The tangled multifilament yarn, free of sizing, has an opening length of 1-6 cm and a knot stability of maximum 2. The filaments are at least mostly coated with a thin film mostly of a hard wax, forming 0.3-2.0 wt% of the total filaments. The film gives adhesion with adjacent filaments, at least at points. Also claimed is a mfg. process of multifilament yarn.

Description

The invention relates to a sized multifilament yarn free of sizing agent.

Tangled multifilament yarns are well known. They are usually made by blowing with a fluid, preferably air. Normal multi-filament yarns have the disadvantage that they can only be processed to a limited extent. If tangled multifilament yarns are used, for example, as warp yarns in weaving, they are subject to a large number of stresses, as described in detail in DE-A-43 27 371, for example. In order to keep these stresses within limits so that as little interference as possible occurs during weaving, it is recommended to use stabilized, size-free multifilament yarns. All multifilament yarns are understood to be stabilized which, in the case of a warp thread tension occurring under the loads on the weaving machine and even with the linen weave L1 / 1 which is classified as particularly critical, have a high thread density, for example a thread density of 40/26 threads per cm warp / weft, not only on conventional, but also and especially on modern weaving machine systems based on weft insertion via air or water, practically without problems can be. Suitable stabilized multifilament yarns are, according to DE-A-43 27 371, all yarns which only have a protective twist and which are nitrided, welded, glued, fused or, in particular, swirled. In order to be able to weave the yarns described there, care must be taken that the thread tension of the multifilament yarn does not exceed 1 cN / dtex in the entire processing until after passing the reed. There is therefore no particular way in DE-A-43 27 371 of how a multifilament can be particularly well stabilized, but it is pointed out that obviously conventional yarns can obviously be used if only the thread tension of the yarns is chosen to be low enough for further processing . However, since the thread tensions in weaving machines, in particular in weaving machines based on weft insertion via air or water, are fixedly predetermined by the machine construction and can hardly be influenced, the route proposed there hardly seems practicable.

Another well-known way of making multifilament yarns suitable for weaving is to provide the multifilament yarns with sizing agents in a separate working step, which, however, have to be washed out of the finished fabric after weaving. From JP-A-52 63 334 it is known, for example, to tangle multifilament yarns first in order to obtain an opening length of 2 to 5 cm (20 to 50 knots per meter), and then with a size in an amount of 0.5 to 3% to be provided. Since a separate work step is required for the application of size, that is to say that the size cannot be combined with the process steps required for the production and further processing, size yarns can be produced only with great effort. As already mentioned, an additional step of sizing agent removal is also necessary after weaving. In addition, this must be followed by a further complex step for environmental reasons the size can be removed from the wash water again.

Furthermore, it is known from JP-A-41 63 336 to add waxes such as carnauba, bee or candelilla wax to the sizing agent which is applied to the tangled multifilament yarns. By mixing size with wax, however, the processing of the washing water with which the size was washed out of the finished fabric becomes even more complex.

The object of the present invention is to at least alleviate the disadvantages described above.

This task is solved by a sizing agent-free tangled multifilament yarn with an opening length of 1 to 6 cm and a knot stability of at most 2, the filaments of which are at least predominantly a thin film consisting predominantly of hard wax, which accounts for approximately 0.3 to 2% of the total weight of the filaments with this film, have and are glued to neighboring filaments at least in places via this film.

It is surprising that the use of hard wax in the case of tangled multifilament yarns already provides good stabilization of these yarns. The value of the node stability is used as a measure of the quality of the stabilization.

The knot stability of a multifilament yarn is determined as follows, reference being made to the figure: In the case of a multifilament yarn that has already been tangled, the opening length T1 is first determined using a Rothschild Entanglement Tester NPT R-2070. A bobbin (not shown) with the tangled multifilament yarn is then presented to a device which simulates the stress in the shed. For this, the Yarn G drawn off over an inlet godet 1 with separating roller 2 at a speed of 52.5 m / min, passed over a second godet 3 with separating roller 4 at a speed of 55 m / min and then over two thread guides 5 and 7 and one Deflection roller 6 deflected in an elongated U. The length L of the legs of the U is 40 cm, while the distance between the legs of the elongated U is set with s = 60 mm in the area between the thread guides 5 and 7 and with s' = 25 mm in the area of the deflection roller 6. After leaving the U-shaped path, the yarn G is drawn off from a third godet 8 with a separating roller 9 at a speed of 57.5 m / min. The numbers noted in godets 1, 3 and 8 (3x, 6x and 8x) mean that the yarn is passed around the respective godet and the associated separating roller several times, according to the number given. For example, the yarn is placed around the godet 3 and the separation roller 4 so that the yarn loops around the godet 3 and separation roller 4 six times.

Between the two legs of the elongated U there is a centrally rotatably mounted beam 10, at the two ends of which a pin 11 made of ceramic (available under the trade name Degussit) is arranged such that when the beam 10 is rotated the yarn G by the distance d is deflected. The position of the yarn at the greatest deflection is shown in dashed lines and labeled G '. The bar 10 and the pins 1, in which the yarn G is deflected the furthest, are likewise drawn with dashed lines. The distance t between pin 11 and axis 12 is 7.5 cm in each case. While the yarn is being drawn through the measuring apparatus in a U-shape, the bar 10 is set in rotation, a constant speed of 100 rpm being maintained. The yarn G is then rewound on a spool (not shown). The opening length T2 is again determined from this yarn G in the same way as described above.

The node stability is now determined as the quotient from T2 to T1.

Since the opening length T2 of the yarn G is generally greater than the opening length T1 before the treatment due to the dynamic load applied to the yarn via the pins 11, values which are greater than 1 generally result for the knot stability. However, it has also been observed that the grazing load on the ceramic pins 11 can result in a, albeit slight, shortening of the opening length T2 compared to T1. In this respect, values of more than 1 were as a rule found in the measurement of node stability, in exceptional cases also values of 1 or less. Values of 0.8 or more were found in the tests carried out to date.

Values for the knot stability of less than 1.0, such as 0.9 or 0.8, clearly show that there are also yarns in the yarns according to the invention whose filament closure even improves during further processing, for example during weaving. Knot stability values of 1 indicate that the yarns behave extremely stably during weaving, while the stability of the yarns increases the more and the frequency of disturbance during weaving the lower the value of the knot stability. Surprisingly, it has now been found that when the yarns according to the invention, which are preferably used as warp yarns, are woven, practically no or only very few thread breaks or other disturbances during the weaving process are found if the hard waxes used according to the invention in the stated amount have a knot stability of less is set as 2.0, preferably less than 1.5. Such low values can hardly be achieved with conventional sizing agents and can only be achieved with great effort, as will be shown with the aid of examples.

Multifilament yarns which have a knot stability of 0.9 to 1.5 are preferred.

Natural and synthetic hard waxes are suitable for stabilizing tangled yarns. The synthetic hard waxes include, in particular, polyethylene waxes and mixtures thereof with different molecular weights, which have been made easily emulsifiable by means of oxidizing aftertreatment processes.

Mixtures of such hard waxes that do not remove the hard wax character are also suitable. Other components can therefore also be mixed into the hard waxes, the type and amount of the admixture having to be selected such that the mixture produced has the typical properties of a hard wax. Soft waxes such as beeswax, paraffin or conventional textile waxes, such as polyethylene oxide, cannot be used for the yarns according to the invention. However, they can be added in such a small amount to the hard waxes used according to the invention that they do not lose their hard wax character.

Other agents, such as, for example, smoothing agents or mixtures of viscous components, can also be added to the hard waxes used according to the invention. In any case, the hard waxes or mixtures with hard waxes used according to the invention do not contain any sizing agents, the disadvantages of which have already been described at the beginning. Although the person skilled in the art is familiar with the usual sizes, the usual sizes are listed below. Usual sizing agents are agents such as are also described, for example, in JP-A-41 63 336, which are water-soluble and contain reagent products made from terephthalic or isophthalic acid, from polyoxyethylene glycol, ethylene glycol, methacrylic butylene, methacrylic laurine or mixtures thereof.

The multifilament yarn according to the invention is characterized in particular by the fact that the film of the filaments consists of carnauba wax or synthetic hard wax, such as, for example, polyethylene wax. It is favorable if the needle penetration, measured according to DIN 51579, of the hard waxes used has values between <1 and 20. It is expedient if these hard waxes have a melting range which is in the range from 65 to 120 ° C.

The object of the invention is also achieved by a process for the production of such a multifilament yarn, in which the multifilament yarn is tangled, then wetted with a thread-closing agent and then wound up, which is characterized in that an aqueous emulsion, which preferably has 10 to 20, is preferred as the thread-closing agent about 15 percent by weight, based on the total weight of the emulsion, of a hard wax, which optionally contains further additives such as emulsifiers, smoothing agents and / or release agents.

When using the method according to the invention, apart from a few exceptional cases, it is not even necessary to provide a drying process after the emulsion has been applied and before the winding. In most cases, the thread speed used in tangling is sufficient for the amount of moisture removed from the ambient air from the thread to which the emulsion is applied that the thread now wound up no longer sticks to adjacent layers of thread. The application can be included in a process customary in production. For example, whenever a tangling of the yarn is provided at the end of the spinning process in the production of POY or HOY yarns, the treatment with the aqueous emulsion can take place directly after the Tangle nozzle and before winding. The method according to the invention is therefore particularly suitable for normal production or further processing a yarn integrated or integrable process step applicable.

The process according to the invention is particularly characterized in that carnauba wax or synthetic hard wax, such as, for example, polyethylene wax, is selected as the hard wax. Hard waxes with a needle penetration of <1 to 10 are particularly preferred.

Although these waxes have previously been used in yarn processing, these waxes have only been used as an addition to the known sizing agents, as evidenced by JP-A-4163336 already mentioned above. It is surprising that it has now been found that excellently stabilized multifilament yarns can only be obtained by using hard waxes without the use of sizing agents. As a result, the complex sizing process can be dispensed with. Since drying is generally not required, the process according to the invention is also particularly economical. Since sizing agents are no longer required, the method according to the invention is also particularly environmentally friendly.

The use of waxes is also known, for example, in mixed yarns, as is apparent from JP-A-61 194 249. For false twist textured yarns, which consist of different groups of multifilament yarns, natural waxes are added there for better weavability. This may be possible for false twist textured yarns. According to the invention, however, it was found that of the natural waxes recommended in JP-A-61 194 249, the wool waxes or the paraffin waxes practically do not have the stability required for the weaving process when applied to tangled yarns.

The invention is illustrated by the following examples.

Examples 1-12

Polyester cop yarns with a total denier of 150 dtex and 48 individual filaments, which contained a matting agent and had a round cross-section, were used. These polyester cop yarns were charged with a 1% wax / emulsifier mixture in different amounts using a ceramic nozzle and wound up without further drying. The take-off speed was 137 m / min, the distance between the location of the order (ceramic nozzle) and the winding was approximately 1 m. The aqueous wax emulsion used had an active ingredient concentration of 6%.

After conditioning for several days in the climatic chamber at 22 ° C / 62% rel. The treated yarns and, as a comparison, the feed yarn were subjected to the stretch-abrasion test described and the knot stability was determined as the ratio of the opening lengths T2 after and T1 before loading. The wax / emulsifier mixtures used and the measurement results are shown in Table 1. In this case, textile wax or paraffin wax was used in Examples 1 and 2, ie in each case one wax which leads to a multifilament yarn not according to the invention. In this respect, Examples 1 and 2 are comparative examples. In example 10, the proportion of hard waxes fell below 0.3%, so that here too, sufficient knot stability was not achieved. This is also a comparative example.

In Table 1, the comparative examples were marked with (V) in the column headed Example. The column headed "T2 / T1 without" shows the knot stability of the starting yarn, i.e. the yarn that did not receive an order. All percentages given in the examples and in the table relate to the total weight of the respective yarn.

The waxes used are identified in Table 1 with numbers which are placed in brackets. The waxes were described following Table 1.

When using the multifilament yarns according to Examples 1 and 2 as warp yarns, there were frequent breaks during weaving, while when using multifilament yarns according to each of Examples 3 to 11 as warp yarns there were practically no breaks.

The multifilament yarns according to the invention, which have been stabilized to the specified level with suitable hard waxes as described above, can be processed as warp yarns on conventional looms with good benefits to give woven fabrics. Table 1 example wax T2 / T1 without Order T1% Opening length Node stability T2 mm T2 / T1 mm 1 (V) (1) 5.1 1.0 20.6 107 5.19 2 (V) (2) 5.1 1.0 20.8 119 5.72 3rd (3) 6.1 1.0 20.8 15.4 0.74 4th (3) 6.1 0.66 19.6 25.8 1.32 5 (3) 6.1 0.33 23.8 42.4 1.78 6 (4) 1.0 25.9 25.5 0.98 7 (5) 1.0 17.4 19.9 1.15 8th (6) 3.6 1.5 17.5 19.0 1.08 9 (6) 3.6 1.0 15.7 25.3 1.61 10 (V) (6) 3.6 0.66 16.5 41.9 2.5 11 (7) 3.6 1.0 20.6 25.4 1.23 12th (7) 3.6 0.66 15.0 22.7 1.51 (1) Textile wax P, polyglycol ether (MW 600) with wax-like properties, manufacturer BASF
(2) Paraffin emulsion C, mixture of 30 parts paraffin (mp. 51-53 C), tallow alcohol x 6EO, spinning preparation K 7334 (Stockhausen) and 10 parts aerosol OT (cyanamide)
(3) Aquacer 611, 35%, non-ionic emulsion of carnauba wax in water, manufacturer BYK-CERA bv; Mp 80-90 C (lit.)
(4) 50% of (1) and 50% of (3)
(5) 2 parts of (3) and 1 part of Rewopal TA 25 S, Tallow alcohol x 25 EO, manufacturer REWO / WITCO
(6) Ultralube W-388, 30% non-ionic emulsion made of approx. 15 parts of polyethylene waxes of different hardness and approx. 15 parts of paraffin (mp / solid approx. 96 C)
(7) Ultralube W-389, analogous to W-388, mp (solid) but approx. 105 C, manufacturer KEIM-ADDITEC

Examples 13-16

In these examples it is shown that the use of sizing agents to which a hard wax is added, as described in JP-A 41 63 336, gives a worse result than when using hard wax without a sizing agent.

Wax (3) was again used as the hard wax. A reaction product of terephthalic acid, sulfoisophthalic acid and glycols, which can be obtained from Eastman as LB 100, is used as the sizing agent. The yarn used in the previous examples was again used as the yarn. The values for the starting yarn were named "yarn" in the Table included. The order quantity and the node stability are shown in Table 2 Table 2 example Size mix Assignment % Knot stability T2 / T1 Hard wax% Plain % yarn 0 0 0 3.1 13 0 100 1 1.2 14 25th 75 1 1.8 15 50 50 1 2.7 16 100 0 1 1.03

A comparison of the data contained in Table 2 shows that the greater the proportion of hard wax in the size, the worse the knot stability. It is all the more surprising that with an application of only hard wax practically better knot stability is achieved than with only sizing agents. If the yarn is pulled off the finished winding body at a speed of 100 m / min, the yarn according to Example 13 shows strongly fluctuating tensions in the range from 0.63 to 1.06 cN, while the yarn according to Example 16 only Tensions in the range of 0.25 and 0.3 cN were measured. Here too, the yarns treated with hard waxes according to the invention will clearly bring about distinct advantages.

Claims (9)

Size-free, tangled multifilament yarn with an opening length of 1 to 6 cm and a knot stability of at most 2, the filaments of which at least predominantly have a thin film consisting predominantly of hard wax, which is approximately 0.3 to 2% of the total weight of the filaments together with this film and are glued to neighboring filaments at least in places via this film. Multifilament yarn according to claim 1, characterized in that it has a knot stability of at most 1.5. Multifilament yarn according to claim 1 or 2, characterized in that the film of the filaments consists at least predominantly of carnauba wax or a polyethylene wax. Multifilament yarn according to one or more of claims 1 to 3, characterized in that the hard wax used has a needle penetration, measured according to DIN 51579, of <1 to 20. A process for producing a multifilament yarn according to one or more of claims 1 to 4, in which the multifilament yarn is tangled and then wetted with a thread-closing agent and then wound up, characterized in that an aqueous emulsion containing 10 to 20 percent by weight, based on, is used as the thread-closing agent the total weight of the emulsion, a hard wax, which may contain further additives such as emulsifiers, smoothing agents and / or release agents. A method according to claim 5, characterized in that the emulsion used contains about 15 percent by weight, based on the total weight of the emulsion, of a hard wax. Method according to claim 5 or 6, characterized in that carnauba wax or polyethylene wax is selected as the hard wax. Method according to one or more of claims 5 to 7, characterized in that a natural or synthetic wax with a needle penetration, measured according to DIN 51579 of <1 to 20, is selected as the hard wax. Use of the multifilament yarn according to one or more of claims 1 to 4 as a warp yarn.

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