DE2058690A1 - Process for the production of random nonwovens with adjustable shrinkage behavior of the deposited threads - Google Patents

Description

METÄILGESEI & SCHAFT Frankfurt / Main, November 23, 1970

Aktiengesellschaft -Schh / HSz-

No. 6374 LÖ

Process for the production of tangled nonwovens with adjustable . Shrinkage behavior of the filaments laid down.

(Addition to patent .... ... patent application P 19 50 669.5)

The invention relates to a method for the production of random nonwovens, In the case of threads made of thermoplastic plastics pressed out of spinnerets, drawn off nozzles operated by blowing agents and thereby highly drawn and then on one a moving, air-permeable surface must be placed -.- -

It is covered by various research reports Melt spinning processes for polyester such. B. the publication by W. Roth and R. Schroth in "Fiber Research and Textile Technology I960" known that with increasing pre-orientation not yet post-drawn polyester filaments the thread shrinkage, measured by the values determined in boiling water, also increases. If the threads are drawn out of the melt via a certain withdrawal speed, if the threads remain in the range of finer titers, the reverse of the case described above occurs: the shrinkage behavior of these polyester threads tends to decrease with increasing orientation. These filaments After all, they can hardly be re-stretched.

All currently known processes for the production of nonwovens from polyester work either with post-drawn staple fibers or continuous filaments or the known high shrinkage effect of polyester fibers with more than 100 % shrinkage is used.

In the case of a fleece, such a shrinkage behavior leads to a length and width shrinkage of approx. 60 to 70 %, ie the area of the fleece is reduced by this percentage.

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In certain production directions, this results in an undesirable stiffening of the fleece, which even makes it completely unusable of the product.

Threads made from other plastics also show a similar behavior, such as B. polyamide.

The invention has the object of the aforementioned disadvantages and to avoid those of the prior art and nonwovens that are produced by the method mentioned at the beginning Nonwoven product.ion ... a._the later post-treatment "adapted_te.s. To give shrinkage behavior.

This object is achieved in that the threads during the drawing off and drawing in a medium of more than 80 be guided. It is advantageous to use air or another propellant with a propellant as the propellant for the exhaust nozzles Temperature of at least 80 ° is used and the threads and the hot air are particularly advantageous in to the draw-off nozzles subsequent guide tubes out. Daa method according to the invention is further characterized in that the threads consist of polyester or polyamide and that a take-off speed of the threads is applied at more than 2 500 m / min.

Fig. 1 shows the relationship between shrinkage, elongation and strength as a function of the blowing agent temperature for threads made of polyester.

The method underlying the invention is in detail z. B. in the patent application P 19 50 559.5 of October 8, 1969 described, the disclosure of which is intended to form part of this application in this regard.

As the figure shows, there is a direct relationship between the temperature of the propellant air in the above Draw-off nozzles and the shrinkage behavior of the filaments and fleeces produced with them. As shown, fall with increasing Air temperatures the elongation at break values of the filaments and surprisingly also the shrinkage percentages, where

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at the same time the thread strength increases. Due to the achievable fixing with a higher molecular orientation of the individual polyester thread If the fleece is subjected to post-heat treatment, the original thread properties, such as higher strength, remain and low elongation at break while maintaining the titer.

To carry out the procedure, it is advantageous to use hot and normal cold propellant air is fed to the exhaust nozzles via a mixing valve. The temperature mixing range is expediently located between 20 to 160 ° C.

The figure gives the textile technological properties of a 1.8 the continuous filament made of polyester again, with during of peeling off under otherwise completely constant conditions, only the propellant air temperature was increased.

It is clear the- dependence on strength and elongation: des Original or virgin filament to be recognized by temperature. At the same time, the shrinkage value decreases.

The advantage of the method according to the invention is that " a significant reduction in shrinkage is achieved at the same time by increasing the blowing air temperature and increasing the thread strength already achieved during filament production.

It was found, surprisingly, that the improvement in Thread shrinkage behavior not only with threads made of polyester, but also with other plastics, e.g. B. polyamide, is achievable.

The following tables show the improvement in the shrinkage behavior again with polyester threads.

Table 1 Values of the original filaments

Propellant air ^{temperature 0} C 20 70 titer den 1.7 1,

Strength g / den2.8 3, elongation% 82 81

Haul-off m / min 3600 38

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100 120 140 160 6th 1.5 1.4 1.1 1.4 2 3.3 * 3.3 4.0 3.6 60 52 47 39 00 4000 4300 5500 4300

2.1 1.5 1.7 1.3 1.2 2 2.1 2.5 ' 2.6 3.3 3.5 1.2 120 60 78 50 35 3.6 percent eat 2a . in the water bath 35 56 55 40 8th 2.0 1.5 1.5 1.3 2.0 2.9 3.1 3.7 85 63 82 53

4 _

Values of the filaments after the shrinkage process 1. in a water bath 1. Shrinkage (30 "/ 58 ° C.) % 27 29 25 15 2 0.6

Titer 2.1

Strength g / den 2.2

Elongation % 120

Values of the filaments according to Schrumi 2a. Shrinkage (3 '/ 58 ⁰ C) % 51

Titer the 2.0

Strength g / den 2.5

Elongation % 130

Values of the filaments after the shrinking process 2b. in air 2b. Shrinkage (5 ^I / 100 ° C) % 74 75 68 56 24

The table clearly shows the dependence on the titer and thus Pull-off speed, strength and elongation from the increase in temperature of the propellant air.

In this experiment, all filaments were initially exposed in groups to a temperature of 58 ° C. for 30 seconds in a water bath and the length shrinkage measured. The progressive shrinkage decrease from 100 C driving air temperature can be clearly seen.

After this water bath, the threads were laid out in a standard climate dried and checked for their textile-technological values .

The same filaments were then placed again in a water bath at 58 ° C., but with a residence time of 3 minutes, and dried and checked. There was practically no change in the physical values, although the longitudinal shrinkage again, above all up to the 120 ° C group, rose sharply.

Some of the threads which had been pre-shrunk below 30 "/ 58 ° C. were used for 5 minutes after-dried for a long time at 100 ° C of agitated air. Even if the shrinkage values were higher than those after the 2nd water shrinkage, the progression curve showed again the progressivity from the 120 C group onwards.

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⁰ C 24 Tabel 100 2 120 130 140 150 Values of the original filaments of a further test series the % 2.6 ■
% the 72 1.9 1.9 1.6 1.7 32 26th 21 1.6 1.7 16C 8th second shrinkage in air 68 63- 48 -31 18th 4th temperature atil 70 22nd Titer g / den 2.2 after boiling shrinkage: g / den 2.7 2.3 3.4 3.2 3.4 3.2 71 pressure strength % 140 Titer % 3.6 100 70 70 60 60 50 2.7 1.9 2.0 1.7 1.4 10. strain m / min 25OC strength 1.6 ) 3400 ι 3400 400C ι 380C ι 4000 ι 3800 1.7 2.8 1.9 2.8 2.4 2.9 3.1 Ab3ugsge-
dwindling Values of the filaments] laugh strain the 200 first shrinking process 3.5 1.9 200 110 110 70 60 1.4 1. Shrinkage
in the water
(3O »/ 58 ° C) 25th after thermo
shrink: g / den 30th 50 170 t 3.7 Values of the filaments Titer % 3.3 380 3.6 2.8 2.0 2.3 1.7 50 daneöi 2nd so-called
Thermoshrink
in air
(5 "/ 180 ⁰ C) strength 1.1 in a water bath 5.2 1.3 1.9 2.5 2.2 2.9 strain 265 15th 1.1 230 156 76 93 86 1.6 85 3.8 40

The values found confirm the earlier tendencies.

The filaments were again pre-shrunk in water at 3 "/ 58 ° C., the shrinkage in length was measured and then subjected to boiling shrinkage and thermal shrinkage in two toilets. Even with somewhat coarser titers, the jump in the numbers from the groups is between 130 and recognize 140 C • au .

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V Birefringence m / min Table 3 100 120 140 160 temperature atü Take-off speed. 30th 22nd 22nd 22nd 22nd pressure the age 22nd 1.7 1.6 ' 1.9 1.9 Titer g / den 1.9 2.5 2.6 2.7 2.9 strength % 2.9 85 76 65 54 strain 87 0, o383 0.0524 0.0701 0.0617 0, o368 3800 4000 3400 3400 3400

Values of the filaments after boiling shrinkage:

Boiling shrinkage % 69 70 68 42 20

Titer the 5.7 5.6 4.8 2.4 2.4

Strength g / den 0.6 0.5 0.6 2.1 2.0

Elongation " % 180 190 220 ... 120 100

Birefringence 0.0012 0.0014 0.0092 0.0336 0.0489

This series of tests also shows the reduction in shrinkage increasing temperatures of the extraction medium.

In order to observe any influence of the hotter blowing air on other polymers as well, the same conditions were used A polyamide granulate BS 07 is used.

Spinneret 15 x 0.25

Throughput 0.576 kg / h

Material BS 07 gloss

Table 4

Troib air pressure const

Propellant air ^{temperature 0} C 30 80 100 Values of the original filaments after the take-off nozzle:

Titre den 1.7 2.4 1.9 -

Haul-off m / min 3400 2400 3000

Strength g / den 5.0 4.1 5.4

Elongation % 91 128 138

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η t 21 140 atü 120 2.4 160 1.9 2400 1.9 3000 5.2 3000 4.5 103 5.0 137 86 BATH ORIGINAL

Values of the filaments
the boil shrinkage: after 4th 4th ,8th 4, 8th 4, 8th 4th , 0 4.0 Length shrinkage values
with boiling shrinkage % 8, 9 '2 , 5 '2, 1 1, 9 2 , 7 2.0 Titer the 1, 8th 3 , 5 3, 7th 4, 1 3 ,8th 4.0 strength g / den3, 1 18th 123 106 120 87 strain % 88

Obviously, the method according to the invention also reduces the shrinkage considerably in the case of polyamide threads.

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Claims (6)

P a t e nt a ns ρ r ü ehe 1) Process for the production of tangled nonwovens, in which the threads made of thermoplastics are pressed out of spinnerets, withdrawn by propellant operated withdrawal nozzles and thereby highly stretched and then on a moving air-permeable substrate are deposited, characterized in that the threads during the removal and drawing be conducted in a medium of more than 80 ° C. 2) Method according to claim 1, characterized in that air or another propellant with a temperature of at least 80 ° C is used as the propellant for the exhaust nozzle. 3) Process according to claims 1 and 2, characterized in that the threads and the hot air are guided in adjacent to the draw-off nozzle Ftihrungsrohren. 4) Method according to claims 1 to 5 ", characterized in that the threads consist of polyester. 5) Process according to claims 1 to 3, characterized in that the threads consist of polyamide. 6) Method according to one of the preceding claims, characterized by a withdrawal speed of more than 2500 m / min. 209825/0879 _ΟΑΛΛ ORIGINAL BATHROOM Blank page