DE3145828A1 - METHOD FOR PRODUCING CONTINUOUS YARN HIGH STRENGTH - Google Patents

Description

The present invention relates to a method for the production of continuous yarn of high tensile strength from thermoplastic resins such as polyethylene, polypropylene, Polyamide, polyester and the like by means of the melt-spinning process and the stretch-drawing technique.

Heretofore, continuous yarns obtained by melt-spinning and draw-drawing thermoplastic resins have been obtained were generally prepared as follows. For example the thermoplastic resin is extruded through nozzles having a round cross section and usually passes a cooling bath or, optionally, is solidified through the use of a treatment bath to form fibrous material. The fiber materials are then at a low Draw ratio of, for example, 3 to 10 and at an optimal temperature that depends on the type of resin used

zes depends, stretched or pulled. In this way, continuous yarns with a strength in the longitudinal direction of 2 g / d to 7g / d produced. About the tensile strength of the continuous yarn to increase becomes the use of a higher one

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Stretching ratio of, for example, 11 to 20 required. In this case, however, although the strength in the longitudinal direction is increased, the knot strength becomes noticeable

5 decreased with the increase in the stretching ratio.

In addition, in order to increase the draw ratio, unstretched High denier yarns are used and, as a result, vacuum bubbles are generated in the yarns because of the variation in heat shrinkage in the cooling step in the inner parts of the yarn. Additionally occur in cases where yarns are at a high draw ratio other problems such as this

Bleaching of the yarns, the generation of flakes and dust on the surface of the yarns, and the like.

Polyethylene yarns in particular are widely used as Fiber materials used for the marine industry because the density of polyethylene is less than 1. The strength However, polyethylene is noticeably lower than that of other synthetic fibers such as polyester and polyamide and similar. For example, the strength of high-density polyethylene ropes is mostly around 70% of the strength of polyester ropes with the same diameter and no more than about 50% of the strength of nylon ropes

with the same diameter. That is why the use is

of polyethylene in products such as tow ropes for large oil tankers where high strength is required.
35

- * - ■ 3H5828

Accordingly, it is an object of the present invention to avoid the above mentioned problems of the prior art and a method for making continuous yarns made of thermoplastic resins with high tear strength, in which the problems of waste the knot strength and elongation fracture in one

large stretching ratio are thoroughly resolved.

Another object of the present invention is to provide a Process for producing continuous yarns from thermoplastic resins that have a tear strength of have about 1.5 to 2 times the tensile strength of conventional continuous yarns without bleaching of the yarns, the method being said to have good operating efficiency.

Further developments and advantages of the present invention are set out in the following description.

According to the present invention is a manufacturing method intended for continuous yarn made of thermoplastic resins with a high tensile strength, in which a melt-spun thermoplastic resin yarn subjected to multi-stage drawing under conditions as follows Fulfill the equation, is subjected to:

DR = -I _n <DR _x ., Χ (1.0 - o, 0970 e ~ ⁰ ' ^{312 X 1} J

öi ί ^T m - ^{37 (i =} i "> ■ ' ^T m - ²⁷ ^ _n , - ¹⁷ (1- ² >

where i is the number of stages of stretching, e is the base of the natural logarithm (i.e. 2.71828), V. is the
linear initial pulling speed (m / min), V. ,, is the

5 linear final pulling speed (m / min) at the i-th

Stretching stage, DRy. is the total draw ratio at the i th draw stage, DR-j-. is the DRt, - »where the yarn
begins to bleach at the i-th stage of drawing, T is the melting point of the thermoplastic resin, and Q is the temperature of the yarn at the i-th stage of drawing.

The present invention is made in connection with
following description and accompanying drawings
better understood. Show it

Fig. 1 is a schematic representation of an embodiment of the arrangement with which the continuous yarn
is produced with high tear resistance

Fig. 2 (a), (b), (c) and 3 (a), (b), (c) schematic Dar positions showing cross-sections of yarn examples made of high-density polyethylene, which with the help of the

Process according to the invention can be obtained and

4 and 5 are a schematic representation of cross sections of examples of high-density yarns
Thick denier polyethylene obtained by the process of the invention
will.

According to the present invention are melted

zene yarns of thermoplastic resin such as polyethylene, polypropylene, nylon, polyester or the like in one multi-stage drawing process stretched at a high draw ratio without bleaching the yarns and To cause stretch fractures. The optimal draw ratio of each draw stage is determined by the draw ratio at which bleaching begins and the number of stretching stages. The optimal yarn temperature each stage is determined by the melting point of the yarn and the number of draw stages.

In the case that DR _Ti > DR _Tiw , problems such as bleaching of the yarn, generation of flakes and dust on the surface of the yarns occur, whereby the commercial value is lost. On the other hand, in the case of ₇ that

DR _Tiw > DR _Ti > DR _Tiw χ _(li0 . O ₅ O _{970 e} -0.312 χ i.

is often undesirable stretching errors, although not

Bleaching of the yarn is caused. Therefore, according to 25

According to the present invention, the multi-stage stretching process under conditions satisfying the following equations to be carried out:

30 DR _Ti < DR _Tiw x (1.0 - 0.0970 e " ⁰ ' ^{312 X 1} J

in addition, the temperature o. of the yarn should be Si ^ T _n , -37 (1.1)

β ti C

a β

• j In the event that the temperature of the yarn is not within of the above-mentioned range, the phenomenon of bleaching occurs or the strength does not become

5 improved even when the stretching is done can.

In the case that the above-mentioned draw ratio is any

Level and the above-mentioned temperature of the yarns.

will hold, yarns with a high tensile strength, for example more than 1.5 to 2 times that of conventional yarns effectively produced without

bleaching of the yarns occurs. 15th

The yarns to be drawn are usually extruded using a screw press. Although any conventional screw extruder can be used for the present inventive method, is preferred
a screw press is used for the method according to the invention, which has a measuring part for the groove depth Hm of

0.157D ⁰ ' ⁷¹⁹ to 0.269D ⁰ ' ⁷¹⁹ (where D is the diameter (mm)

the bore of the extruder). In case that

If the depth of the groove is less than 0.157D ⁰ ' ⁷¹⁹ , the production capacity will be less, and besides, a

Heat generation of the resin occur, causing various 30

Problems such as the occurrence of vibration of the yarn and smoking during extrusion and generation of flakes and dust: In the case that the groove depth is greater than 0.269D ', can

a discoloration of the yarns and stretch breaks occur, which are due to the reduction in the mixture of the resin are to be supplied.

The nozzles through which the yarns are extruded in the melt spinning process can be of any desired cross section have a sectional shape such as circular, oval, capsule-shaped or dumbbell-shaped. Especially nozzles, the one 10

Cross-sectional area S (mm ² ) have the following

Satisfy the equation:

0.503mm ² < S £ 3.14mm ²

0.09 6 -ςτ < 0.30

can preferably be used in the melt spinning step

will. In the equation, I represents the maximum secondary 20

Section moment represents, max (I, I) _; that is, the maximum moment of the secondary cross-sectional moments related to the main axes χ and y, which go through., the center of the _ center of gravity of the cross-section.

The cross-sectional shapes of the nozzles preferably used in the present invention are oval-shaped, capsule-shaped (or elongated circular shape), dumbbell-shaped and the like, the cross-sectional area S 0.503 to 3.14 mm ² and the maximum secondary ^{cross-sectional moment 0.09 S 2} to

4th
0.30 S is ² mm. Particularly is the use of an oval-shaped nozzle with a long axis ratio a

ΛΛ

t to the short axis b (ie, a / b) from 1.2 to 1.6 is desirable. This is due to the fact that the manufacture of nozzles becomes difficult and expensive when the cross-sectional shapes of the nozzles become complicated. The desirable L / De (where L: leading phase length in mm, De: diameter (mm) = Zy = corresponding to a full circle) of the nozzles is 10 to 15. Although there are no limitations in the structure of the leading phase, the straight leading phase is in terms of manufacturing cost and accuracy of manufacture (or cutting)

desirable. The desirable arrangement of the nozzles in FIG

a die is such that the χ or y axis, the

go through the center of gravity of the cross-section of the nozzles and which has a smaller secondary cross-sectional moment, tangent to the pitch circle diameter (P.C.D.) is. If the nozzles are reversed, the fluctuation generated in the undrawn yarns can be reduced Heat shrinkage is not noticeably countered. Using of the above-mentioned nozzles, vacuum bubbles are very difficult to form in the undrawn yarns , even in the case that the yarns are drawn at a high draw ratio, the undesirable ones occur Draw failures do not occur, and yarns with high knot strength can be obtained.

As mentioned above, in the melt spinning step applied nozzles preferably a cross

-jr.

Sectional area S from 0.503 to 3.14 mm ² and a maximum cross-sectional moment from 0.09 S ² to 0 _s 30 S ² mm. In the case where the cross-sectional area S is smaller than 0.503, the manufacture of the nozzles becomes difficult and, since melt fracture may be generated during the melt-spinning step, drawing cannot be performed at a high draw ratio. On the other hand, in the cases where the cross-sectional area is larger than 3.14 mm ² , the spinning pressure becomes small, so that the flow becomes uneven and the yarns tend to be cut just below the nozzles, whereby

the yield of the yarn becomes lower.

In cases where the maximum secondary section moment i is less than 0.09 S ² mm (e.g. in cases

S ² 4

of complete circles, I = ^ - = 0.0796 S ² mm), vacuum bubbles tend to occur in the undrawn yarns and therefore the desired high stretchability cannot be achieved. When the high drawing is carried out, drawing failure is caused more often, and yarns with only a low knot strength can be obtained at a low yield. On the other hand, in those cases where the maximum secondary transverse

30 4

cutting moment I is greater than 0.30 S ² mm, although the above-mentioned problems can be solved, thinner parts are produced in the yarns, so that the yarns tend to ^a

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¹ tes to tear and the production of, for example, ropes becomes difficult.

In addition, those are applied to the melt spinning step 5

deten nozzles preferably carried out in such a way that

the thermoplastic resins melt extruded can be seen at a nozzle thrust of 150 to 900 ". In the event that the nozzle thrust is lower than 150 see ", the spinning pressure is reduced and therefore, the extrusion speed changes, thereby producing products of irregular denier will. In contrast to this, melt fractures can occur in cases where the nozzle thrust rate is greater than 900 occur easily and soiling occurs on the spinnerets over longer periods of operation, where-

^ can be cut through the yarn under the nozzles.

Further, the draw ratio f (ie, f = V ^ Vg where V _{n is} a linear extrusion speed at die discharge (m / min), V _{1 is} the linear drawing speed (m / sec)) should preferably be within the range of 1.00 to 3 .50 (usually 0.5 to 1.5 in the case of a perfect circle). In the case that the draw ratio is less than 1.00, the desired increase in the strength of the yarns is due to the insufficient molecular orientation

* - ι * ■ ι

not reached. On the other hand, in cases where the stretching ratio is greater than 3.5, Problems like stretch failure 1, bleaching of the stretched one

5 yarn and the like.

A typical embodiment of the method of The present invention will now be explained with reference to the drawing.

As shown in Fig. 1, a thermoplastic Resin in the molten state with the help of a screw extruder 1 is extruded and then passed through a cooling bath, with undrawn yarns 11 being produced. Optionally, the yarns can be reinforced through the use of a treatment bath (not shown in Figure 1)

will.

The undrawn yarns 11 are drawn at a high draw ratio at an optimum temperature, which depends on the type of thermoplastic resin. the For example, as shown in Fig. 1, initial yarns 11 are first subjected to a first stage drawing in a warm Water bath 4 subjected to first draw rollers 3. Then the yarns pass through second draw rollers 5 and Preheating rollers 6, wherein the yarns are preheated to an optimum temperature that of the used thermoplastic resin depends. The preheated cooking ne are subjected to a second stretching stage, if

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sie.by the heat rollers 7 are passed. The stretched ones Yarns are passed through end draw rollers using a winch 10, optionally you can with The annealing heat rollers 9 can be annealed by means of the annealing heaters. Although the shape, the arrangement and the end surfaces of the rollers used in the method of the present invention are not particularly limited is the use of holding rollers is desirable so that the yarns do not slip.

The high draw ratio can be known by any Technology, for example by cold water stretching processes, Hot roll stretching process, hot plate stretching process, hot air bath stretching process and so on. These stretching methods can be used individually or in any combination.

As is known from the prior art, the longitudinal strength of stretched fibers becomes largely influenced by the stretch ratio. Since ent-25

according to the present invention, an extremely high one

Draw ratio can be applied, yarns can be produced with high tear strength. In addition, the knot strength according to the present ver The yarns produced are 30% to 50% larger than conventional yarns with the same draw ratio. In addition, according to the present 35

Invention produces yarns with high elongation.

According to another embodiment of the present Invention is a taper stretching, by

constriction deformations occur, preferably with the help of the water stretching process and ultra stretching ken after the necking deformation is completed with the help of heat rollers. Multi-stage stretching means usually that the yarns are drawn in two or more stages. The physical properties, in particular, the strength of the yarns is improved with an increase in the number of drawing stages. the However, installation costs are increased as the number of stretching stages increases. Therefore, after practical A three- or four-level point of view

²⁰ routes used.

As mentioned above, according to the present invention, neck stretching in which necking deformations occur is preferably carried out using cold water stretching methods applied. Especially in those cases where the stretching, where the necking deformation occurs ^ at a deformation rate of 50 min "or less and where the subsequent multi-stage stretching after the end of the necking deformation is carried out at a deformation rate of 20 min "or less, can

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desirable results can be achieved. The rate of deformation when stretching is defined by

- ^v i

^L i

wherein L _i is the effective stretching distance (m) stage i at stretching, V * is the linear conveying speed (m / min) of the yarn at the i-stage stretching and V.. is the linear drawing speed (m / min) of the yarn in the i-stage drawing.

When the deformation rate during the taper stretching larger than 50 min ", problems arise that include formation of voids in the yarns, bleaching the surface of the yarn and the appearance of

Include stretch fractures. To oppose it,

when the deformation rate during the multi-stage Stretching after the end of the constriction deformation is less than 50 min ", frequent stretching failures and therefore a sufficiently high draw ratio cannot be used.

The draw ratio at each stage may preferably be set to be around 0.2 to 0.5 times less than the stretch ratio at which Bleaching occurs. It is also recommended that the

Taper stretches at a temperature of 100 ⁰ C or 35

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less is carried out and that the subsequent multi-stage stretching after the end of the constriction deformation at a temperature of 100 ⁰ C or

5 more is carried out.

In the event that the polyethylene yarn corresponds to * according to the present invention is generated

preferably polyethylene with a melt index of 10

0.1 to 0.9 g / 10 min used. In the case where the Melt index of polyethylene is less than 0.1 g / 10 min, problems can arise that the production of Melt fracture during spinning, a poor drawing property, a drop in draw ratio at which the bleaching occurs and a high draw ratio impossible to include, so that yarns having high tensile strength cannot be obtained. on the other hand it is difficult in cases where the melt index of polyethylene is greater than 0.9 g / 10 min high tear strength, although a large stretch ratio can be used.

Furthermore, it is desirable to have a ratio of a high load melt index to a melt index (i.e. high load index / melt index) of polyethylene is 40 or less. In the case where the ratio is one High load index is greater than 40, can not only achieve the desired strength in the longitudinal direction and knot strength 35

- «r- 3K5828

speed of the yarn can be achieved, but also the spinning ability is reduced, which cuts the yarns under the nozzles, unless nozzles with a

5 a diameter that corresponds to the desired denier, are used in the period when the denier of the yarn is changed.

Among the polyethylene resins having the above-mentioned

Melt index and the ratio of high! Knot melt index to have melt index, medium and high density polyethylene resins can preferably be used are made in terms of pressability and strength. These resins can be, for example, a homopolymer of ethylene and its copolymer with another monomer. These resins can optionally be a heat stabilizer, an aging agent, a lubricant, a matting agent, a pigment, a flame retardant, contain a propellant and the like.

In addition to polyethylene, can be used in the production

of yarns according to the present invention also other thermoplastics which can be used in the melt spinning process Resins such as polyamides, polyesters, polypropylene and the like can be used.

In the case where a high density polyethylene is used in the present invention, which is a melt index from 0.1 to 2.0 g / 10 min, a density of 0.950 35

up to 0.960 g / cm ³ and a ratio of high-load melt index to melt index of 20 to 35, high-density polyethylene yarns with high tensile strength and the following properties can be produced continuously.

Tear strength. (G / d): 11.0 - 15.0 Elongation at break (%): 4.0 - 10.0

Modulus of elasticity (kg / mm ² ): 1600 - 3200

Melting point ( ⁰ C): 136-145

The denier of those produced in accordance with the present invention high density polyethylene yarn is preferably as thick as 600 denier or more in terms of thickness Ease of manufacture. The shape of the cross-sectional areas can be any shape. Examples of such forms are shown in Figures 2-5. Especially yarns with cross-sectional areas according to FIGS. 4 and 5, in particular Figs. 5 are desirable because these shapes require the following winding and rotating stages in the manufacture of ropes simplify, and such ropes have a high tear strength and flexibility.

These high-density polyethylene yarns with high tensile strength can preferably be used in place of nylon ropes, especially in the field of ropes for large ships (e.g. holding ropes), since the tear strength is equal to the tear strength of nylon, the

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Density is less than that of water because of the cost of production Less than half the cost of nylon production and low shrinkage

5 is.

As already mentioned above, according to the present invention, continuous yarns with a high tear strength can be produced that are 50 to 100% larger than the 10

of conventional continuous yarn. In the case where a cold water route, which has the highest heat transfer coefficient is used during the first stretching stage, the constriction point can be set and uniform yarns can be obtained. In the case of heat rolling during the times and the following stretching stages are used, the freedom of choice of the number of stretching stages is increased and compared to other techniques including hot plate processes, warm air processes and others, the installation costs of the

^ direction and the operability is improved.

The present invention is explained further below with reference to examples and comparative examples, the invention is not limited to these examples only.

Examples 1 to 4 and Comparative Examples 1 to

High density polyethylene with a melt index of 35

10

15th

20 25 30

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0.45 g / 10 min and a density of 0.955 g / cm ³ was extruded in the molten state and subjected to multi-stage stretching after cooling under the conditions as shown in Table 1 below. In this way, continuous yarns were produced. The results are shown in Table 1.

The common production conditions other than those shown in Table 1 are as follows.

35

Extrusion press: 40 mm 0, L / D = 24 Slug : Compression ratio of 3.2 Crusher plate: 2.0 mm 0 86H Sieve pack: five (80, 100, 120,150 and 100 meshes) Number of nozzles openings : 40 Temperature of Extrusion press: C ₁ = 160, C ₂ = 250, C ₃ = 290 D ₁ = 290, D ₂ = 290 ( ⁰ C) Air gap: 5 cm Temperature of Cooling bath: 17 ⁰ C Stretching temperature First stage : 100 ⁰ C (wet process) Second step : 115 ⁰ C (hot rolling process) Third step : 115 ⁰ C (hot rolling process) Fourth stage: 12O ⁰ C (hot rolling process)

1 test methods of physical properties of Continuous yarn:

0IS (Japanese Industrial Standards) -L-1070 5 clamping distance = 30 cm,

Pulling speed = 30 cm / min, Temperature = 2O ⁰ C

Relative humidity = 60% 10

Table 1

1 Example el . 3 4th Cf. ** - eichsbei game 4th 2 1 2 3 Pressing conditions 2.16 2.59 2.75 - 2.21 Draw ratio f 2.01 2.58 2.01 2.19 1.36 3.49 2.80 1.99 Cross-sectional area (mm ² ) 0.1011 1.89 0.2577 0.1272 0.785 - 2.01 2.01 0.08649 I / S ² stretch
the circle 0.1036 dumbbell-
formal g oval 0.07958 10.0 0.07958 0.07958 stretch
ter
circle shape 1.3 oval 2.3 1.6 completely
mener
circle completely
mener
circle completely
mener
circle 1.1 Flatness ratio 1.3 1.0 1.0 1.0 Stretch ratio of 13.0 13.0 13.0 13.0 first stage 1 13.0 10.0 10.5 10.0 Stretch ratio of 1.13 1.13 1.13 1.13 second stage 2 1.13 - 1.25 Stretch ratio of 1.04 1.04 1.02 1.04 third stage 3 1.04 - 1,1,5 Stretch ratio of - - 1.13 - fourth stage 4 15.3 - 15.3 16.9 - 1.05 15.5 Total draw ratio
_) 1 : , 15.3 10.5 15.5

Table T (continued)

1 example 3 4th 14.0 Comparative example 1 2 3 4th 2 3.7 Physical own 8.0 societies 2.2 Denier of un- 6120 5100 5700 4000 4200 4950 6120 stretched yarn (De) 5100 Denier of the stretched 399 340 335 ■ 398 395 319 396 ten yarn (De) no break
at 6 hours
or more 337 no no break
Break at 6 hours
. at or more
6 hours
or more 1 / 6h 2/3 hours 15/2 hours 5/3 hours Extensibility
(Number of stretch
fractions per time) 12.8 no
fracture
at 6 hours
or more 12.0 8.0 8.8 12.2 12.5 Longitudinal strength
(g / d) 3.6 ' 13.3 4.0 5.7 5.3 2.7 2.8 Knot strength
(g / d) 8.8 3.9 8.3 18.0 15.9 7.8 8.4 Elongation (%) 2.2 8.9 2.8 9.0 7.6 1.9 2.1 Knot elongation (%) 2.6

(C 9 £ # • S »

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- 2Os -

As can be clearly seen from the results in Table 1, according to the present invention, the Stretching ability can be improved and no significant stretching failures occur. Furthermore, what the strength of the continuous yarn thus obtained, yarns with a high longitudinal strength and a high Knot strength in Examples 1 to 4 can be obtained.

In contrast, the longitudinal strength was in comparison example 1 low, perhaps because of the low draw ratio f and the low draw ratio. In Comparative Example 2, the longitudinal strength is also low, much light because of the low stretch ratio. In Comparative Example 3, the stretchability is very poor, much less because of the low maximum secondary section moment, although the draw ratio and the stretch ratio were increased. In Comparative Example 4, the stretchability was also poor, because of the low maximum secondary cross-sectional

25 ments.

Examples 5-9 and Comparative Examples 5-7 -

High-density polyethylene with a melt index of 0.45 g / 10 min and a density of 0.955 g / cm ³ was extruded in the molten state and, after cooling, subjected to a multi-stage stretching process under the conditions of Table 2. In this way,

1 made the continuous yarn. The results are in the table 2 shown.

The common production conditions other than ^{5 shown} in Table 2 are as follows.

Extrusion press: 40 mm 0, L / D = 24

Screw: compression ratio of 3.2

Breaker plate: 2.0mm 0 χ 86Η

Sieve pack: five (80, 100, 120,150 and

100 mesh) Number of nozzle openings: 40
Temperature of

Extrusion press: C ₁ = 160, C ₂ = 250, C ₃ = 290

D ₁ = 290, D ₂ = 290 ( ⁰ C) air gap: 5 cm
Temperature of

Cooling bath: 17 ⁰ C

Physical property test methods of the continuous yarn:

JIS (Japanese Industrial Standards) -L-1070 clamping distance = 30 cm

Pulling speed = 30 cm / min, temperature = 2O ⁰

Relative humidity = 60%

- η

Temperature = 20 C

* DR _Ti - 5 B e i s ρ ι Table el 7th Ie 2 9 Compare chsbeisp iel e 6th * ν a h < OO Ϊ
(«Ti 2.01
0.7958
completely
mener
circle
1.0 6th 1.89
0.1036
oval
1.3 2.01
0.1272
oval
1.6 4th 5 1.99
0.08649
stretch
ter
circle
1.1 ¹ w.: Ί K)
CXD t ι Π i i ς ρ 13.0
14.7
15.3 2.01
0.1011
stretched
Circle
1.3 13.0
14.7
15.3 ' 8th 13.0
14.7
15.8 2.01
0.07958
completely
mener
circle
1.0 2.01
0.07958
completely
mener
circle
1.0 13.0
14.7
15.3 4 *
C »II t
« (· ' % Cross sectional area
(mm ² )
I / S ²
shape
Flattening a / b 13.0
14.7
15.3 2.01
0.07958
completely
mener
circle
1.0 10.0
13.0
15.6 13.0
14.7
15.3 ϊ f
f "« Stretch ratio 7.0
10.0
13.0 t DR _T1
^DR T2
^DR t1 14.0
15.5
16.4 14.5
15.7
16.8 14.3
15.5
16.4 14.0
15.5
16.4 Stretch ratio at 14.5
15.7
16.8 14.0
13.5
14.2 14.0
14.7
14.7 incipient bleaching 14.0
11.5
14.0 ^DR T3w 13.0
14.7
15.8 13.5
14.9
16.2 13.3
14.7
15.8 13.0
14.7
15.8 upper limit stretch 13.5
14.9
16.2 13.0
12.8
13.7 13.0
13.9
14.1 relationship* 100
115
115 100
115
115 13.0
10.9
13.5 100
110
120 100
115
130 ^DR T1M
^DR T3M TiW 100
115
115 _e -0.312 100
115
115 100
105
130 Yarn temperature ( ⁰ C) , 0-0.0970 95
110
110 Pz
03 x i \

Table 2 (continued)

example Comparison example Stretching method

First stage, second stage and further stages

wet wet wet wet wet wet wet wet Heating Heating Heating Heating Heating Heating Heating Heating roller roller roller roller roller roller roller roller

Denier of the unstretched Yarn (De)

Drawn Yarn Denier (De)

Condition of the chamois

Extensibility Number of breaks / time

Longitudinal strength (g / d) Knot strength (g / d) Longitudinal elongation {%) Knot elongation {%)

5120

334

6120

339

5100

337

6320

403

5000 320

5120

333

6120

396

by by by by 6th 11.6 by part 1 - ge by sighted sighted sighted sighted 4.3 sighted wise ge bleaches sighted shiny shiny shiny shiny 9.8 shiny bleaches shiny shiny zend zend zend zend 3.8 zend some zend zend glittering 1/6 hour no no 1/6 hour no Break at Break at Break at 10/2 hours 2/3 hours 5/3 hours 6 hours or 6 hours Hrs or more or more more 12.7 12.8 13.3 13.5 12.2 11.7 12.5 2.9 3.6 3.9 3.5 2.7 2.9 2.8 8.7 8.8 8.9 7.1 7.8 7.0 8.4 2.0 2.2 2.6 2.0 1.9 2.7 2.1

OO f-O

As clearly seen from the results in Table 2, according to the present invention, continuous yarns having a high tear strength can be effectively produced without the occurrence of bleaching of the yarns. In contrast, in Comparative Example 4, the stretchability is poor and the bleaching occurs partly because of
DR _T. > DR _x . χ (1.0 - 0.097Oe " ⁰ ' ^{312 x T} ).

Similarly, in Comparative Example 5 occurs the bleaching of the products and the strength is somewhat reduced due to the fact that. not

the condition T _m - 27 < Q ^ f T _m - 17 is met.

Examples 10-13

Production of high tensile strength yarns

High density polyethylene having a melt index of 0.51 g / 10 min according to the JIS-K-6760 method and having a density of 0.953 g / cm ³ was extruded in the molten state under the conditions shown in Table 3 and, after quenching, became a multistage Subjected to stretching. In this way, continuous yarns were produced. The results are shown in Table 3.

30th

The common conditions of production, other than that

shown in Table 3 are as follows.

Extruder: 50 mm 0, L / D = 24 screw: compression ratio of 4.0

Crusher plate: 2.00 mm 0 130H 150 and ) Sieve pack: five (80, 100, 120, drive) 100 meshes) drive) Number of nozzles 140 C (hot rolling process) openings : 60 16 kg / hr Temperature of C ₃ = 290 uen Extrusion press: C ₁ = 160, C ₂ = 250, ( ⁰ C) D ₁ = 290, D = 290 Air gap: 5 cm Temperature of Cooling bath: 15 ⁰ C Stretching temperature First stage : 100 ⁰ C (wet process Second step : 115 ⁰ C (hot rolling curve Third step : 115 ⁰ C (hot rolling curve Fourth stage: Production rate: Manufacture of Ta

Ropes with a thickness of 12 mm were made accordingly the JIS-L-2705 method in which the above generated High tensile strength polyethylene yarns were used.

The results are shown in Table 4.

Test methods of the samples
The physical properties of the continuous yarn were

-μ - Ό. '3Η5828

JIS-L-1070 and 1073 methods specified, wherein a clamping distance of 30 cm, a pulling speed of 30 cm / min, a temperature of 20 ⁰ C and a relative

5 humidity of 60% was taken as a basis.

The physical properties of the cords were determined according to JIS-L-2706 and 2704.2705 methods, wherein a temperature of 20 + _ 2 ⁰ C and a relative

Air humidity of 65 + _ 2% were taken as a basis.

Comparative Examples 7-9
The physical properties of the commercially available polyethylene yarns, polypropylene multiple yarns and nylon multiple yarns and the ropes having a thickness of 12 mm including each yarn were determined in a manner described in Examples 10-13. The result

The results are shown in Tables 3 and 4.

Physical properties of the yarn

Pressing conditions

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with 12 mm 0 10 Well Ta bei Ie 4 12th 13th Cf. oak at spi el 9 dew Weight kg / 200m 13.5 quite
Well By S pi el 14.8 14.5 7th 8th 18.2 Breaking force (t) 2.53 very
small amount 1 1 2.66 2.80 14.5 14.3 2.83 Elongation at break (%) 26.0 swims 15.6 21.0 15.0 1.43 1.70 53.0 ro
f 1 Strength at 37.4
Unit weight (kgm / g) 110 3.12 36.0 38.5 32.0 38.7 31.1 actually ( Shine and color 17.0 Well Well 19.7 23.8 Well ii ι φ
# 11 rrl flexibility 40.0 very good quite
Well Well Well very good goes out
of the Tc Shrinking Well very
small amount very
small amount quite
Well- Well very
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great sinks JZ
Q. Relative yarn
cost per
Unit strength very
small amount 114 100 swims swims 264 swims 167 173 105

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10

20th 25th 30th

Examples 14-16 and Comparative Examples 10-16 High density polyethylene containing 0.5% of zinc stearate, 0.1% of 2,6-di-tert-butyl-4-methylphenol, 0.1% of calcium stearate, 0.05% of dimyristyl thiodipropionate, was extruded in the molten state and, after cooling with water, stretched according to the conditions shown in Table 5. Continuous yarns thus prepared were produced. The results are shown in Table 5.

The common conditions of production, other than that shown in Table 5 are as follows.

Extrusion press: 40 mm 0, L / D = 24 ^C 2 ⁼ 120, 150 of 3.2 Slug : Compressi on relationship s D ₂ = Breaker plate 2.00 mm 0 x '86H and Sieve pack: five (80, 100, 100 meshes) Number of nozzles 250, C ₃ openings : 40 290 Temperature of = 290 Extrusion press: C ₁ = 160, ( ⁰ C) D ₁ = 290, Air gap: 5 cm Spinning speed no: 110 m / min Temperature of the ab cooling bath: 17 ⁰ C

35

1. Stretching temperature

First stage: 100 ⁰ C (wet process) Second stage: 115 ⁰ C (hot rolling process) Third stage: 115 ⁰ C (hot rolling process)

Fourth stage: 12O ⁰ C (hot rolling process) Test methods for the physical properties of continuous yarn:

JIS (Japanese Industrial Standards) -L-1070 and 1073
Clamping distance = 30 cm

Pulling speed = 30 cm / min temperature = 2O ⁰ C-

Relative humidity = 60%

Polyethylene density (g / cm ³ 14th Table e 5 10 11 Compare 12th 13th example 0.35 15th 16 M.I. (g / 10 min) ) o, Example el 0.964 0.945 0.954 14th 45 0.953 0.953 ' H.L.M.I./MJ. 0.83 15th 16 0.35 0.02 1.5 0.953 0.953! 1.7 0.35 0.35 N Groove depth of the measuring zone 36 954 0.948 ( 3.953 57 43 38 0.51 590 45 45 (O Nozzle thrust rate (see " ¹ ) * 1 3.0 0.2 0.60 2.4 3.6 2.0 32 1 2.4 2.4 Surface rough 400 35 24 590 400 320 2.4 I. 590 590 skill level * 2 1 3.6 3.0 1 3 1 1250 1 1 C. Number of under the I. 320 590 I. I. 4th 12th I. I. O
t / l Nozzle cut off 1 1 J ^ Yarn * 3 0 I. I. 2 4th 0 0 0 Rate of deformation 10 40.0 X
UJ (min- ¹ ) first stage 0 0 12.0 second step 40.0 30.0 40.0 28.1 4.2 72.0 40.0 third step 12.0 - 12.0 6.9 40.0 - 12.0 fourth stage 4.2 28.1 40.0 - 4.2 3.5 12.0 - 4.2 Stretching ^{temperature (0} C) - 6.9 12.0 - - 15.6 4.2 100 - first stage 3.5 4.2 - 115 second step 100 15.6 100 100 100 115 100 90 third step 115 - 115 115 100 - - 98 (U fourth stage 115 100 100 - 115 115 115. 15.3 - 98 U Stretch ratio - 115 .115 - - 140 115 20th - - (U Extensibility * 4 15.3 115 115 13.0 15.3 16.0 - 13.0 15.3 + ■>
to +> Longitudinal strength (g / d) 0 140 - 1 15th 2 15.3 O Of CU rxCf
η ϊ r hi 5 7th j2 knot strength (g / d) 12.0 16.0 15.3 9.9 ctrprkpn 10.5 5 Il IUlIt
possible , 9.9 10.4 <J longitudinal elongation (%) 4.5 0 0 3.2 3 Ul CU i> CII
ni rhi " 3.7 12.2 ¹ 3.0 1.7 {= Knot elongation (%) 9.2 15.0 14.5 10.9 Il IUlIO
possible 7.0 2.7 11.2 6.5 LU cn 2.9 3.4 4.0 3.9 1.8 7.8 3.5 2.0 co 7.0 8.0 1.9 2.3 2.5 Q.

3M5828

* 1 number of strokes

= -4L- Q: extrusion volume (cm ³ / sec)

R: Relative nozzle radius (cm)

* 2 The degree of surface roughness was visually observed according to the following standards:

1: Very good 10 2: Good

3: Possible yield point

4: surface roughness

5: Extreme surface roughness

* 3 The number of under the nozzles during a spinning operation Yarns cut for 1.5 hours were counted.

* 4 The number of times during a stretching operation of Yarns cut for 1.5 hours were counted.

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Claims (8)

3K5828 COHAUSZ & FLORACK PATENTAN WALT8BÜRO SCHUMANNSTR. 97 D-4000 DÜSSELDORF 1 Telephone: (0211) 68 33 46 Telex: 0858 6513 cop d PATENTANWÄLTE: DipHng. W. COHAUSZ Dipl-Ing. R. KNAUF Dipl.-Ing. H B. COHAUSZ · DipHng D H. WERNER claims 1. A method for producing continuous yarn having a high tensile strength from thermoplastic resin characterized in that a thermoplastic resin melt-spun yarn has a multi-stage Subjecting the stretching process under conditions satisfying the following equations: ^DR Ti ⁼ ~ Ύγ- i DR _Tiw χ (1.0 - 0.0970 e " ⁰ ' ^{312 x 1} J S ₁ * T. -37 ti-1) T _n , - 27 «θ C T _B -! 7 <1> 2) where i is the number of stretch stages, e is the base of the natural logarithm (i.e. 2.71828), V ₁ is the initial linear pull speed (m / min), V. is the final linear pull speed (m / min) at the i-th Draw stage, DR- ^ is the total draw ratio at the i-th draw stage, DR _Tiw is the DR at which the yarn at the i-th draw stage l i begins to bleach, T _m is the melting point of the thermoplastic resin and Q ^ is the temperature of the yarn at the i-th drawing stage. 2. The method according to claim 1, characterized in that the continuous yarn from a melt spinning process thermoplastic resin is extruded through a nozzle having a cross-sectional area S (mm ² ) satisfying the following equation * '0.503 mm ² <S <3.14 mm ² 0.09 <^ 0.30
where I is the maximum secondary section moment max (I, I) (i.e. the maximum secondary torque in x y the cross-sectional secondary moments with respect to the main x-axis and the main y-axis that go through the center of gravity of the cross-section). 3. The method according to claim 1 or claim 2, characterized in that a tapering stretch _; in which necking deformations occur while cold water stretching is applied, and multi-stage stretching is carried out by means of heated rolls after the necking deformation is completed. 4. The method according to claim 1 or claim 2, characterized in that that polyethylene with a melt index from 0.1 to 0.9 g / 10 min and a ratio of high load melt index to a melt index of 40 or less is used. 5. The method according to claim 1 or claim 2, characterized in that that the extrusion of the continuous yarn is carried out with the aid of a screw extruder, the one measuring part with a groove depth Hm of 0.157D ' to 0.269D 'mm, where D is the bore diameter 1 knife (mm) of the extruder is. 6. The method according to claim 5, characterized in that polyethylene with a melt index of 0.1 to 0.9 g / 10 min and with a ratio of high load melt index to melt index of 40 or less in molten state is extruded at a Nozzle thrust from 150 to 900 see "and that that extruded continuous yarn is drawn. 7. The method according to claim 6, characterized in that that the neck stretching at which the necking deformation occurs at a deformation speed of 50 min "or less and that multi-stage stretching at a strain rate of 20 min or less will lead " ^V i ^L i where L- is an effective stretching distance (m) at i-stage gen routes, V. is the linear conveying speed (m / min) of the yarn at the i-th drawing stage and V ^ ₊₁ is the linear final draw speed (m / min) of the yarn at the i-th drawing stage.
30th 8. The method according to claim 7, characterized in that the taper ^{stretching is carried out at a temperature of 100 0} C or less and that the multi-stage stretching after completion of the taper stretching at a Temperature of 100 ⁰ C or more is carried out.