DE2631519A1 - PROCESS FOR THE DRESSING OF IN PARTICULAR BLENDED STAPLE FIBER YARN MADE OF AT LEAST 30% POLYAETHYLENE TEREPHTHALATE ON WARP FIBER YARN - Google Patents

Description

The invention relates to a method for dressing mixed fiber yarns made of at least 30% polyethylene terephthalate fibers, especially for the production of a warp yarn of this Composition of suitable yarn material.

For the production of warp yarn in the weaving mill one usually proceeds in such a way that the yarn with an adhesive, mostly on Based on starch, polyvinyl alcohol or carboxymethyl cellulose, however, these finishing materials must be prepared from the Tissue can be removed by e.g. enzymatic decomposition or washing, and that means to a significant extent involvement in water pollution by the textile industry. Furthermore, for drying the yarn after a such sizing treatment of the fabric after washing

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Dust and flakes, respectively, in the course of treating the undone How the trimmed yarn material is created pose a further problem. Build-up of dust and flakes have a considerable effect despite the suction devices that are usually present, especially in the washing and shearing systems alone disruptive, quite apart from their harmful effects on health through inhalation of the working air Dust, which can lead to breathing difficulties and other impairments of the operating personnel (byssinosis).

Finally, the development of flakes and dust is also very disadvantageous in the processing system, apart from fiber dust starch particles can also make a not insignificant contribution. This disadvantage can be overcome with the aid of suction devices control to a certain extent so that the dust content remains below a required limit in the weaving product and the claims the operating conditions in the weaving mill are not harmful to health. However, that requires Extraction devices with a required energy consumption that exceeds that of the existing generating facilities.

The invention is thus mainly based on the object to provide a process for the production of particular staple available, ä ^ & suitable for processing as warp "the so-called drawbacks no longer

or in any case occur to a significantly reduced extent.

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The method according to the invention consists essentially in that the mixed fiber yarn for at least one second one Temperature between 230 ° and 260 ° Celsius is exposed.

It has been found that by such a heat treatment of the mixed yarns at a temperature at which polyethylene terephthalate begins to soften, mutual sticking of the fibers takes place, increasing the tensile strength of the yarn

increased and the flaking value of such a yarn is reduced so that it can be without further treatment with a Sizing agent can be used as a warp yarn.

In addition, it has been shown that dust formation with this procedure is only a few percent above that of the corresponding Yarns which, however, have been dressed in a conventional manner.

Polyethylene terephthalate fibers of those used in the present invention Kind can be continuous fibers, but are preferably used as staple fibers.

If the above-mentioned heat treatment is not continued unnecessarily, i.e. not for an unduly long time, it will be impaired

they only low the tensile strength and elongation of the yarn. at

Yarns that are spun on ring frames are found to have only a small reduction of about 10%;

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whereas the yarns, which are manufactured according to the so-called "open-end" method show a tendency towards a certain increase in strength.

The modulus of elasticity depends on how long the treatment lasts, subject to an increase of 10 to 50%. In the case of fabrics made from these yarns, no opposite flow could be found the heat treatment on such goats can be determined. In Regarding the tendency of a joint storage, the so-called. "Pilling effect", which in principle is always present in fabrics made of mixed yarns, an improvement could in any case be ascertained in relation to the fabric structures that were produced according to methods that are customary in the relevant industry.

It has thus been found that the fabrics are finnished, such as bleached, dyed and fat-resistant can be made in a known way without special pretreatments, which could lengthen the work process.

In the case of a prolonged heat treatment, e.g. a heat treatment at the highest mentioned temperature of 260 ° C for over significantly more than 30 seconds, the properties for the usability of the yarn, e.g. its breaking strength, deteriorate such that the yarn becomes unusable for various applications.

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Apparently, after such a treatment, the molecular orientation of the fibers of polyethylene terephthalate is abolished and the adhesion between the fibers becomes so intimate that Yarn becomes tight and brittle. In view of this, the yarn is preferably subjected to the heat treatment for no longer than 30 seconds exposed.

Expediently, the yarn is not subjected to a greater tension than approximately 8% of its tensile strength during the heating treatment, since in the event of greater stress the fibers could slide over one another as a result of the softening of the thermoplastic fibers and thin sections or tears in the yarn as a result the yarn is subjected to a tension that is not greater than what is avoided in this way, the puckering of the yarn.

The invention relates to the yarn as it is according to the treatment can be obtained according to the invention and which is characterized in that it is woven as a warp thread can without subjecting it to a special device or post-arbitration treatment.

For the purpose of explanation, the following description is used to provide a schematic representation of a system for practical purposes Application of the method according to the invention in detail described.

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Mixed yarns are fed from a yarn feed e.g. from bobbins or conical bobbins via a yarn brake 2 and a napping comb 3 passed to a heating furnace 4, in which the yarn undergoes a heat treatment in a closed heating circulation system is subjected, for which the heating furnace is equipped with an electrical heating system 5 and a fan 6 is. A temperature of approximately is maintained in the heating furnace 250 ° C and thereby the mixed yarn to a temperature in the range of the beginning melting range of the polyester fibers heated up.

Behind the furnace there is a tensioning roller 8 via which the Mixed yarn after leaving the oven via the napping comb 7 and then via a napping comb Io finally to the adjustable winding unit 11 arrives.

The transport or tensioning roller 8 is driven by a drive roller of constant speed with a drive is coupled, the running speed of which depends on the length of time that one wishes to have for the heat treatment of the mixed yarn, depends

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The setting of the yarn brake 2 is such that during the heating process the tension of the mixed yarn is not greater

is than 8% of the tensile strength of the yarn.

With an apparatus of the type described with reference to the examples given below, the following were made. Results achieved:

example 1

A normally spun yarn of 30 tex, consisting of 65% Polyethylene terephthalate and 35% cotton was passed through the plant, at a different time at all times Speed so that the heat treatment was a different time each time. The temperature was in set to 250 ° C in each case. The wear resistance, the peeling value, of the yarns treated in this way was determined and the modulus of elasticity.

In this process, the number is under wear resistance understood from twists until a break occurs in the yarn, which is fastened crosswise over a wear device twisting the yarn up and down against steel pins and against itself.

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This is a standard method for wear testing as it is currently used in weaving. is common. (See Ir. K. van Harten and

Ir. N.J. Faasen - Transactions of the General Textile Institute 57 (1966) T 273).

The abrasion number is understood to be the sum of the stress peaks that can occur due to the splitting of pre-worn parts Layers of yarn (10 threads each) that was attached

via a simulated Weberlcamm.

For mixed yarns (usually prepared accordingly) this number does not have to be more than 800 to 1,600 grams; very

well prepared is 400 br§ * 500 grams or less and e.g. 4,000 to 5,000 grams is bad and cannot be woven (see Ing. J. D. Feikema and Ir.N.J. Faasen - de Tex 2S (197O), No. 4, page 293, Fig. 5).

The results obtained in Example 1 can be seen from

Table A and when comparing with untreated mixed yarns,

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Table A.

CD CD CX) OO

σ oo ro ο

Treatment of normally spun mixed yarn at 25O ° C, polyethylene terephthalate / cotton 65/35, 30 tex (Ne ₁ 20).

Contact time
in seconds Elasticity . Wear resistance number
when turning 25,000 Desquamation 35 25th X Il 1600 ² ) 19th 24 X Il 1500 ' 10 20th X 9,800
1.025 ¹ ^ 2730 5
2 19th
19th X 345 ²⁾ 17ΟΟ ² }
490 ^x; 1 18th 202 690 ¹ ) 0.5 17th 165 183Ο ² ) 0.25 17th

χ = extremely high

1) favorable value

2) value which is still acceptable in practice, untreated, normally spun Mixed yarn

17th

(not to be determined

without dressing
non-weaving.

Example II

A 30 tex yarn, spun using the "open end" method and made of 65% polyethylene tereptitalate and 35% cotton was used for each at different speeds through the system, so that the heat treatment is different each time took a long time. The temperature itself was regulated at 250 ° C. in all cases. From this so treated and also from

the yarns that were not treated in this way became more wear-resistant, the peeling value and the modulus of elasticity are determined.

The following table shows the corresponding results.

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Table B.

Treatment of one according to the "open end" method at 250 C polyethylene terephthalate / cotton 65/35, tex (Ne _χ 2ο)

Contact time in seconds

cn ο <x> oo

ο oo ro σ

10

15th

20th

35 23 19th 23 10 23 5 21 2 21 1 21 0.5 18th χ extremely high l) favorable value 2) still usable value ο low

Elasticity? - Resistance to wear modulus in turns

χ 25,000 X "

j X 13,000

X 10,000 χ 3,400

1) 725

2) 380

Peeling value

not determined

61

111 113

548 2148

Untreated manure yarn, spun using the "££ end ^{M" method}

11.5 360

Cannot be woven without dressing.

K) CD Ca?

Claims (5)

Patent claims: 1. A method for dressing, in particular, mixed staple fiber yarn made of at least 30% polyethylene terephthalate fibers on warp yarn, characterized in that the yarn is exposed to ^{a temperature between 230 ° C. for at least one second.} 2. The method of claim 1 wherein _p marked _'s characterized by exposing more than 30 seconds, the yarn of the said temperature. 3. The method according to claim 1, characterized in that the tensile stress in the yarn is kept at less than 8% of the tensile strength during the hot treatment. 4. The method according to claim 2, characterized that the yarn is practically tension-free. 5. Yarn, produced according to claims 1-4 _P, characterized by a wear value of over 350 and a defined flaking value of less than 2000. 609885/0820