DE1510570A1 - Polypropylene twine - Google Patents

Description

This invention relates to polypropylene yarn and, more particularly, to polypropylene tie yarn and its manufacture.

According to the invention, polypropylene yarn is made from one or multiple strips or ribbons of uniaxially oriented isotactic polypropylene film by folding and twisting of the strip or strips produced under conditions that deform the film into a yarn

The strip (s) used to make the yarn will be described first. The polypropylene has an isotacticity of at least 85 i "and more generally at least 95%. (Iaotacticity is synonymous with insolubility in boiling heptane). The intrinsic viscosity of the polypropylene is in the range of about 2-4 g dle /, generally in the range of about 2-3 dl./g (in decalin at 135 ⁰ C) · comparison, the melt flow rate is in the range of about 0.1 - 12 g per 10 minutes, more generally in the range of about 2 to 10 g per 10 minutes, (ASTM D 1238 - 57 T, 2160 g load

^{at 250} ° ^E) · 009838/1972

BATH ORIGINAL -2-

In those cases where it is based on the weight per unit of length arrives and a yarn with a larger average diameter is desired, it can be advantageous to use foamed Use polypropylene to make the yarn o

Foamed polypropylene films from which ultimately foamed Yarn can be made is made by polypropylene in the presence of a propellant

"Which decomposes at the temperature of extrusion by means of extruded" This temperature is usually in the range of about 175 to 260 ⁰ G, however, can Werin poly-r propylene is used having a higher molecular weight, higher temperatures are used, it is only one. Small amount of propellant required. Usually about 0.04-0.4 wt.% based on the polypropylene is used, more generally about 0.1-0.2 wt The polypropylene can be mixed homogeneously with the polypropylene in any way, for example with a Prodex-Henschel mixer »The polypropylene used to produce a foamed film

k usually has a melt flow rate of at least about 3.0 g per 10 minutes, more generally from about 4 to 12 g per 10 minutes (ASTM-D 1238-57 T, 2160 g load at 230 C) «This polypropylene can be present as a powder or in the form of pearls. Powdered polypropylene is used preferred because a more homogeneous mixture is achieved with the propellant

The processes for producing the film, which is used as a preliminary product for the strips, are known. Polypropylene powder or beads are in a commercial extruder to a fleece or film of the desired thickness and Width extruded expediently a very wide

009838/1972 ~ ³ ~

BATH ORIGINAL

the film is extruded, which is then cut to the desired width being split and trimmed »The width and thickness of the extruded film depends on the final desired Width and thickness of the strips that are twisted into the yarn * Because during the subsequent processing The film's thickness and width can be changed The width and thickness of the film depends as well as that on the Orienting the film draw ratio applied to the amount of trimming i

An internal lubricant is preferably incorporated into the polypropylene prior to extrusion. This can be seen according to known methods inorganic lubricants are _t those that are identified as layers of solids and sometimes referred to as solid or dry lubricant. These materials öihd characterized by a marked cleavage along their base surfaces and include such compounds as mica, talc, MOSP and graphite. the lilenge of internal lubricant sehwankt in generally λ between about 0.1 and 8% by weight, based on polypropylene.

The film is then oriented by stretching, whereby its tear resistance is increased. »A useful method of uniaxially orienting the film is to let the film unroll from a hell that rotates slower than the receiving room» with the film between the two Rolling at an elevated temperature, usually between about 90 and 150 ⁰ C, holds. The film can be oriented in a single step or in two or more steps. In order to achieve better results, the orientation in several, preferably two stages, is preferred

Q09838 / 1972 " ⁴ "

BATH

That means that the movie to achieve the final Orientation is stretched at least twice

The total draw ratios used to orient the film are at least 6.5: 1, preferably 7.0 ί 1 o This means that either in a single stretching or in a series of stretchings, the final draw ratio is within the specified limits. Preferably the final draw ratio is between fc 7fO and a value just below the point at which fiber formation occurs. In general, the maximum draw ratio does not exceed 10. If the film is stretched twice, is the draw ratio for the first orientation is generally about 2 - 5 t 1, wherein the desired final draw ratio is achieved with the second orientation. If desired, the originally emtruded film can be of such a size that the oriented film can be cut into strips of the desired width.

The size of the strip or strips depends on
of versions f to use / number and of the desired Garndimen-. For a certain desired yarn take the
The dimensions of the film strip decrease as the number increases
of strips; conversely take the dimensions of the
Filmstrip increases as the number of filmstrips decreases. However, there is a minimum and a maximum of the width and thickness of the stripes that must be adhered to in order to obtain satisfactory yarns. The thickness of the film strips should be in the range from about 0.01 to 0.15 mm, preferably from 0.02 to 0} mm. The stripe width is generally in the range of about 2 to 6.5 cm.

The length of the strips is generally equal to the length

-5- 009838/1972

BATH ORIGINAL

of the yarn. This can be achieved by joining strips together or continuously extruding the film so that a film of "infinite" length is obtained which is cut to the desired length ο

The oriented strips have tear strengths, expressed than the loads necessary to tear apart, in the range of 2800 to 6000 kg / cm. (A 1.27 cm wide test strip is placed in the jaws of an Instron apparatus stretched, which are set at a distance of 6.35 cm, and is driven at a speed of 25.4 cm / min, stretched «The load when tearing is determined) «The percentage elongation when tearing is generally 20 to 50 # ·

The strips described above can now be twisted into the yarn. The strip or strips are quickly passed through an opening or a compactor, the dimensions of which are only slightly larger than the diameter of the yarn, as a result of which the strip or strips are folded. The folded strips are then subjected to a twist of about 3 to 25 turns per 30.5 cm, preferably 8 to 15 turns per 30.5 cm. The yarn is then wound onto a hasp}. Usually, the yarn is twisted at ambient temperature and cold worked "However, the film prior to folding to temperatures of room temperature (20 0) can be heated to about 150 G, the attached £ - ~ ^v ~ ne upper limit leads to a heat deformation. While the strips are being spun or twisted, a commercially available external lubricant such as mineral oil, polyglycols or wax can be applied to the film or yarn by conventional methods.

009838/1972 ~ ⁶ "

BATH ORIGINAL

After the film is twisted into the yarn and the yarn is wound onto the bobbin, the yarn usually becomes one ball-shaped winding that can be used in the binding machine. This wrap must have the yarn from release inside and must have a stable shape so that it neither collapses nor telescopes winds up when the thread is drawn ah. The one to manufacture Machines used by sisal rolls can easily be applied to the production of rolls from the inventive. Polypropylene yarn can be converted.

The number of strips used to form the yarn is generally 1 to 12, more often 1 to 6, preferably 2 to 4.

The twine according to the invention generally weighs between about 0.4 and 3 g per 25.4 cm, more generally about 0.75 to 1.5 g per 25.4 cm. The diameter of the yarn lies ranging from about 0.2 to 0.5 cm, more generally from about 0.25 to 0.38 cm. The diameter of the yarn can be slightly by increasing the strength of the polypropylene strips or can be changed by using foamed polypropylene. The yarn has strength measured as a load up to tearing of at least 90 kg and generally at least 113 »5 kg · The knot strength, measured as the load to the point of tearing, is generally at least 63 »6 kg and mostly at least 68.2 kg.

These strengths were determined in accordance with ASTM D138-62 T (see ASTM Textile Materials Standards, 33rd Edition, Oct. 1962) using an Instron device with clamps with semi-inwardly curved surfaces measured »the jaws

- 7 -009838/1972

BATH ORIGINAL

moved at a speed of 25.4 cm / min. The results were obtained as the load in pounds and converted into kilograms

The yarn has a relatively smooth surface that allows it to to slide easily over the rough surfaces of the grain to be tied, rather than being held in place by the stalks and to be rubbed off «Its largely uniform diameter allows a perfect Operation of the binder. In addition, perfect knots f

knotted and the yarn lightly cut, resulting in smooth cuts and no frayed loose ends.

The following examples serve to explain and not the limitation.

example 1

Commercially available polypropylene beads dit an intrinsic viscosity of about 2.5 dl./g (in decalin at 135 ⁰ O), a melt flow rate of about 2.5 to 4.0 and an isotacticity of 95 # were placed in a conventional extruder handeis- i . The maximum weight:; temperature between the polymer and the; Extruder, and the temperature of opening was about 26O ⁰ O · The injection port was set to 0.381 mm and a sieve with 177 micron mesh size was used. The extruder screw rotated at a speed of 25.5 rpm and delivered 305 cm of film 0.127 to 0.152 mm thick and 13.2 µm wide per minute.

The film was trimmed to 3 inches by 3 inches and at a draw ratio of 7.0 and a temperature

- 8 0 098 38/1972 _BA0

oriented from 135 ⁰ O · The final film strip had a thickness of 0.0254 mm and a width of about 5 »5 to 6p1 om"

Two strips of this film were placed simultaneously and placed one on top of the other in a Jenny spinning machine which had a compactor with an opening of 0.536 cm and a modified claw consisting of three pulleys, with which twisting on the compactor front surface was prevented. A lubricant, 1ji monyloxyphenoxydodecaoxyethylene alcohol in water, was added
the twisted strips sprayed as they exited the compactor and before they entered the claw. The strips were twisted 11.5 turns per 30.5 cm. The resulting yarn had one
Diameter 9V <ttn about 0.254 cm and a weight of 0.78 g per 25.4 cm.

The table below lists the strengths of various films that have been used to make yarn at various draw ratios, and the
The strengths of the yarns obtained from aolchen films were compared using the methods described in Example 1
were applied.

-Qm,

009838/1972

BATH ORIGINAL

Travel strengths

Movie

Seiss STRENGTH, kg / em ² Γ i » elongation to the point of tearing

Yarn

Load until tearing, kg Kaote strength, kg

Table 1

AWAY

Orientation (draw ratio) 6.5: 1 7.0: 1

3660 4010 340 34 104 118 73 73

7.5: 1

4220 28

118 73

/ "*" A 1.27 om wide sample is clamped in the jaws of an Instrom device, 6.35 cm apart are removed and we stretched at a speed of 25.4 cm / min. the Load when tearing is measured

"" ** * Z ⁺ * ASTM D 1380-62 T

As ASTM D 1380- 62 T, but with a knot in the middle of the 25.4 cm long sample "

OO
OO

to

HO

Example 2

The procedure of Example 1 was repeated, but the strips were cut to half the width, i.e. to about 3 »05 cm, and four strips were used to give a yarn weighing about 0.87 grams per 25.4 om. The diameter of the yarn was about 0.254 cm. The yarn had a tenacity, measured as a load to break, of 123 legs and one Knot strength of 77 kgo

L Example 3

Commercially available polypropylene beads were mixed with the lubricants to be tested in the desired proportions mixed in a Banbury mixer until mixture was relatively homogeneous. In some cases the lubricant was incorporated as a concentrate in polypropylene beads, and these pearls containing the concentrate with the Polypropylene beads mixed in a Banbury mixer. The polypropylene combined with the lubricant became then under the same. Conditions as in Example 1 extruded.

The film was then trimmed and oriented by drawing in which w in Table 2 given draw ratio. Usually a lubricant was sprayed onto these film strips before they were rolled onto the reel. The strips were twisted under the conditions given in Example t. After winding onto the reel, the yarn was wound into a winding which could be used in a binder. The ao wound yarn was then examined for heat resistance and knot strength «

In some cases the twine was used as a twine in one commercial binders used, alfalfa ,. Wheat or barley taken straw and a bale density of

-1t- 00 98 3 8 / T9: 7 2

BATH ORIGINAL

· Was 149-160 kg / m is chosen in the table are the yarn tension upon binding, io mean the percentage efficacy -100 that no failure was about slipped means that no node or yarn crack - and the knot strength and tensile strength of the yarn in kg Load given when tearing

The following table shows the results.

0 0 9 8 3 3/197?

BATH

'.3 orientation Temp.
⁰ C Filmstrip broad weight Tabel CVl Inner. To 25th Winding up Knot »
festkto Binder test Effective
samko Festi ekei Pulling
Relation 135 thickness cm G
25th Sliding m.
Ge w. Io Stretch kg to
. Reisso 75 100 yarn
* S Knot 7.0 / 1 135 τητη 6.1 O ₁ number From s. Poly- 26.5 118 73 Chip
tion 100 100 77 7.0 / 1 135 .0254 5.84 O. Movies
i.Garn Sliding
medium " ¹ " len ₅ 25th 123 75 2 100 95 75 attempt 7.0 / 1 135 .0254 5.84 O,
O, 2 (a) - 23 120 61 2 100 86 68 No CD 7.0 / 1 .0254 4.82 O. 2 (a) Flakes-23 111 2 104 • 70 A. 09838 135 .0254 2 (b) 1 73 2 B. 7.0 / 1 5.84 O, 2 - Molyb
dändi
sulf id
1 107 σ .0254 Per
), 4 cm D. , 37 2 (a) .38 E. .39)
.36) .38 .37

7.0 / 1 135 .0254 3.05 Ο.2θ "

120 82

^ (a) 0.9 parts Carbo.wax 1000) - - * _± water

_o 0.1 parts Nonyloxyphenoxydodecaoxyäthylenalkohol) ^'uew · ^ ⁱⁿ water

5 (b) 1 io nonyloxyphenoxydodecaoxyethylene alcohol in water

= T ++ The weights are average weights for two strips.

r- ₊₊₊ Du Pont "Alathon 4470" with a density of 0.936 ·

++++ Dixon No. 35 graphite,

with a size below 74 microns.

~ 13

Example 4

The procedure described in Example 3 was repeated, but a two-stage was used to orient the film Stretching applied *

The table below gives the draw ratio of the first draw and the total draw ratio, as well the same data as listed in Table 2 ο

-H-009838/1972

Tabel

Orientation 1. "" 27 " Ges ·

Vers. Pulling

3Jr. mated C zieia-

4 m.

Binder test

Filmstrip strength

Thickness Width Weight Number Outer _o Inn « After winding up, chip- % yarn knots

g / films sliding- sliding- "^ kg knoting active kg kg 25.4 iο twine mid-mid. Stretching to tight

mm cm

cm

Hotness

speed

A 3.3 / 1 135 7.6 / 1 B 3.2 / 1 135 7.6 / 1

C 3.2 / 1 135 7.6 / 1

CD CD

D J £ 4.9 / 1 135 7.6 / 1 co

OO

E ^ 4.9 / 1 135 7.6 / 1 co

P ¹ ^ 3.3 / 1 135 7.6 / 1 & 3.3 / 1 135 7.6 / 1

H 3.3 / 1 135 7.6 / 1 I 3 * 3/1 135 8.0 / 1

141 .028 5.08
5-08 0.38)
0.38) 2 yes Gra
phit
++++ 1 30th 1 32 68 5-7 XBEBB 100 141 .028 5.34
5.34 0.37)
0.37) 2 yes Gra
phit
+++ 1 30th 1 32 73 141 .0254 5.34
5.34 0.37)
0.37) 2 no gra
phit
+++ 1 29 1 27 64 141 .028 5.34
5.34 0.37)
C.37) 2 yes gra-
ohit
++ 1 30th 1 32 84 0 114 141 .028 5.34
5.34 0.37)
0.37) 2 no gra
phit
+++ 1 33 1 30th 70 0 109 141 .028 6.1
5.59 0.44)
0.37) 2 yes Gra
phit
+++ 1 1 30th 77 141 .028 5.59
5.34 0.39)
0.39) 2 yes Gra
phit
+++ 1 1 30th 82 141 .0254
.0254 6.1
6.1 0.40)
0.39) 2 yes Gra
phit 1 30th 85 141 o0254
.0254 5.84
5.84 0.39)
0.38) 2 phit
+++ 1 1 20th 73

70

73

Table 3 (continued) Orientation

Pilma strips

Binder test

> · ^ # ^ "- ¹ ^ ¹ U ^{0 ÜJ} " ^C Al OJtX "** ii T * Jü * i ¥" * "^ * Γ * im i *"" ^W

Vera.Zieh- Sea. Thickness Width Weight Number of uaa. Inn, flat winding tension. Yarn knot no. ⁰ O draw- ⁰ G mm cm g / Fifcme Gleit- ffleit - "^ Eg Knot, 4 ratio 25.4 in the yarn middle + middle stretch to fea-

cm weight 96 Reias. tig-

speed

J 3.3 / 1 135 7.6 / 1 141 .0254 5.59 0.41) 2

5.59 0.40)

K 3.3 / I 135 7.6 / 1 141 .03 10.7 0.78 1
L _O 3.V 135 7.6 / 1 141 .066 5.3 0.83 1

CD CO

M £ 4.0 / 1 135 9.5 / 1 141 2

yes gra- 32 138 82
phit
++ 1

yes Graphi-fc +++ 1

yes graphite +++ 1,

yes graphite +++ 1

N '^ 3.2 / 1 134 7.6 / 1 138 .053 7.6 0.96 4 no graphite

κ, +++ 1

Q 4.0 / 1 136 7.6 / 1 HO .028 10.4 0.68 3 none graphite +++ 1

0.79 2 no graphite +++ 1

P 4.0 / 1 136 7.6 / 1 139 .036 9.9

+ 0.9 parts Oarbowax 1000)

0.1 part nonylphena & cydodecaoxyethylene alcohol in water) ++ Dixon "Microfyne" graphite, 95% below 44 microns
l · Acheson "# 39" - Graphite, 98 # under 74 microns
■ r Dixon # 635 graphite, $ 75> under 74 microns

118 77 4-5

114 68 3-4

138 82

134

152

123

Wt. $ In water

Strength 10 kg kg

82

91

145 68

Example 5

Commercially available polypropylene powder (melt flow rate 2.6 ~ 4.5 g at 2160 load and 230 ⁰ C) was mixed with the blowing agent azobisformamide, the -vorlag also as a powder and an internal lubricant in the desired proportions added in a Henschel mixer until the mixture was relatively homogeneous. The polypropylene combined with the blowing agent and lubricant was then extruded under conditions similar to those described in Example 1

The foamed film obtained was then trimmed and stretched at the draw ratio shown in Table 4. the Strips were stretched under the conditions given in Example 1. After being wound on a reel they were wound into a roll that could be used in a binder · The foamed yarn was then tested for tensile strength. The results obtained are shown in Table 4.

- 17 -

009838/1972

orientation Tabel

Filmstrip

Vers β Melt- Drift- Zi-eh- (+1) Ges _e (+1) Durch- Width Density An Auss _e Inn. Strength after

No. Fluid ratio ~ pull- see, «a» ™ ^ number sliding- sliding- winding

% ^υ bewo ⁰ C thickness cm ^{g / cm} stripe, medium medium kg to Seissen

τη τη

A.
B.
C.
D.
E.

speed

i.Garn

3 «3-3«> 7 0.4 4/1 135 7.6 141 »098 2.54 0.78 3.3-3.7 0.25 4/1 135 7.7 141 .080 3.18 0.78

3 3-3ο7 0.15 4/1

2.6 0.15 4/1

4.0 0.15 4/1

4.5 0.10 4/1

135 7.8 141 .057 406 0 "84

135 7.8 141 .124 2.16 0.72

135 7.8 141 .104 2.46 0.78

135 9.1 141 .097 2.49 0.78

2 no + ■ Gra
phit -1 96 2 no + Gra
phit -1 109 2 no + Gra
phit -1 109 2 no + Gra
phit -1 100 2 no + Gra
phit -1 99 2 no + Gra
phit -1 98

+ Graphite particles - 98-100 fo smaller than 74 microns

O O co OO CaJ CO I. CO OD NJ

In some cases, the foamed yarns have been tested as a binding yarn under severe operating conditions. the The knot strength of these foamed yarns was that of unfoamed yarn equivalent, and was in some Cases measurably higher.

From the results of the above tables it can be seen that the polypropylene yarns according to the invention deliver excellent results when binding grain and in their properties equivalent to sisal yarns or are superior. The polypropylene yarns according to the invention not only have an equal or superior knot strength compared to sisal yarn, but allow also an error-free way of working with the conventional machines and also show others Advantages over sisal yarn, such as resistance to rot. The following results show this superiority

Both sisal and polypropylene tie yarns were on their resistance to natural and artificial weather conditions examined. The loss of strength during the duration of the experiment is shown in the following Given in the table

- 19 -

009838/1972 bad original

Table 5

untied yarn

Travel strength (kg)

Requirementg · Klimateater + Polypropylene ( Hours.) Sisal 107 0 H2 44 89 200 61 70 600 9 39 1000 2.3

Discoloration tester ++ sisal polypropylene

Sacramento, California
Sisal polypropylene

107

95

142
116

107
93

= *. CXJ CO ι , O

Climate tester (Weather Ometer): The experiment consists in the fact that one samples for varying periods of time Subjects to light and spraying with water according to the ASTM E42 ~ 57 method using a Type ι D-G devices with two carbon arc lamps and a 102-18 cam; spraying with water took place at Ambient temperature.

Discoloration tests were carried out like the climatic tests, but only a carbon arc lamp was used and no spraying with water carried out

Eb is obvious to the skilled person that in the sense of Yoratehen description and considerations numerous Ab. changes made to the method according to the invention without deviating from the scope of the invention, or from the webs formed by the following patent claims

- 21st

009838/1972

Claims (6)

1. Synthetic yarn made from polypropylene film strips, characterized in that the strips are made from isotactic polypropylene exist, uniaxially oriented at a draw ratio between at least 6.5 and a value just below the fiber formation point are, are substantially continuous and at least 1.27 cm wide, and under conditions in which the strips become a yarn are deformed so ^ are twisted that 3 to 25 turns 30.5 cm length come « 2. Yarn according to claim 1, characterized in that there is a contains internal lubricant. 3. Yarn according to claim 1 or 2, characterized in that it contains Λ an external lubricant. 4. Yarn according to claim 1, 2 or 3 * characterized in that it contains between 1 and 6 strips of polypropylene film. 5. Yarn according to one of the preceding claims, characterized in that that it contains graphite as the internal lubricant and a nonionic surface-active agent as the external lubricant. 6. Yarn according to one of the preceding claims, characterized in that that the film strips at a draw ratio of 7: 1 have been stretched to 10: 1. 7 · yarn according to one of the preceding claims, characterized ä marked by the fact that the film strips of foamed polypropylene exist. For CALIFORNIA RESEARCH CORPORATION San Francisco, Calif. V.St.A. Right 00 9838/1972