U.S. patent application number 10/000288 was filed with the patent office on 2002-09-19 for method of spinning, spooling, and stretch texturing polyester filaments and polyesters thereby produced.
Invention is credited to Dulling, Achim, Klein, Alexander, Mirwaldt, Ulrich, Wandel, Dietmar.
Application Number | 20020132116 10/000288 |
Document ID | / |
Family ID | 27214138 |
Filed Date | 2002-09-19 |
United States Patent
Application |
20020132116 |
Kind Code |
A1 |
Wandel, Dietmar ; et
al. |
September 19, 2002 |
Method of spinning, spooling, and stretch texturing polyester
filaments and polyesters thereby produced
Abstract
The present invention comprises a process for producing and
spooling preoriented polyester filaments comprising at least 90
weight % (relative to the total weight of the polyester filaments)
polybutylene terephthalate (PBT) and/or polytrimethylene
terephthalate (PTMT), preferably of PTMT, wherein, a) the spinning
delay is set in the range of 70 to 500; b) the filaments,
immediately after exiting from the spinning nozzle, pass through a
cooling delay zone from 30 mm to 200 mm in length; c) the filaments
are cooled off to below the solidification temperature; d) the
filaments are bundled at a distance of between 500 mm and 2500 mm
from the lower side of the nozzle; e) the tension of the thread in
front of and behind the removal galettes is set to between 0.05
cN/dtex to 0.20 cN/dtex; f) the thread is spooled with a tension of
the thread of between 0.025 cN/dtex to 0.15 cN/dtex; g) the
spooling speed is adjusted to between 2200 m/min. and 6000 m/min.;
h) and from 0.05 weight % to 2.5 weight % (relative to the total
weight of the filament) of an additive polymer is mixed as an
expansion-promoting agent.
Inventors: |
Wandel, Dietmar; (Hanau,
DE) ; Dulling, Achim; (Koln, DE) ; Mirwaldt,
Ulrich; (Maintal, DE) ; Klein, Alexander;
(Ingelheim, DE) |
Correspondence
Address: |
Michael S. Greenfield
McDonnell Boehnen Hulbert & Berghoff
32nd Floor
300 S. Wacker Drive
Chicago
IL
60606
US
|
Family ID: |
27214138 |
Appl. No.: |
10/000288 |
Filed: |
November 2, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60263013 |
Jan 19, 2001 |
|
|
|
Current U.S.
Class: |
428/364 ;
264/103; 264/211.14 |
Current CPC
Class: |
D01F 6/92 20130101; D01F
6/62 20130101; Y10T 428/2913 20150115 |
Class at
Publication: |
428/364 ;
264/103; 264/211.14 |
International
Class: |
D02G 003/02; D01D
005/088; D01F 006/62 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 3, 2000 |
DE |
100 54 422.3-26 |
Claims
We claim:
1. In a process for producing and spooling preoriented polyester
filaments that comprise at least 90 weight % (relative to the total
weight of the polyester filaments) polybutylene terephthalate (PBT)
and/or polytrimethylene terephthalate (PTMT), the improvement
comprising (a) synthesizing the polyester comprising the PBT and/or
PTMT with from 0.05 weight % to 2.5 weight % (relative to the total
weight of the filament) of a polyester expansion-promoting agent;
(b) spinning the polyester produced in (a) into filaments in a
spinning nozzle with a spinning delay in the range of 70 to 500;
(c) passing the filaments through a cooling delay zone of from 30
mm to 200 mm in length immediately after exiting from the spinning
nozzle; (d) cooling the filaments to below the PBT or PTMT
solidification temperature; (e) bundling the filaments into thread
at a distance of between 500 mm and 2500 mm from the spinning
nozzle; (f) setting the thread tension in front of and behind
removal galettes to between 0.05 cN/dtex to 0.20 cN/dtex; (g)
spooling the thread with a thread tension of between 0.025 cN/dtex
to 0.15 cN/dtex and a spooling speed between 2200 m/min. and 6000
m/min.
2. The process according to claim 1, wherein the PBT and/or PTMT
are used with a limiting viscosity in the range from 0.7 dl/g to
0.95 dl/g.
3. The process according to claim 1, wherein the temperature in the
vicinity of the thread coil during the spooling is
.ltoreq.45.degree. C.
4. The process according to claim 1, further comprising storing the
POY spools for at least 4 hours at 12 to 35.degree. C. and at 40 to
85% relative humidity before further processing.
5. The process according to claim 1, wherein the spooling speed is
set between 2500 m/min. and 6000 m/min.
6. Preoriented polyester filaments wherein after 4 weeks of storage
under normal conditions in accordance with DIN 53802, the filaments
have the following properties: a) an elongation upon tearing
between 90 and 165%; b) a processing shrinkage of at least 30%; c)
a normal uster below 1.1%; d) a double refraction between 0.030 and
0.058; e) a density less than 1.35 g/cm.sup.3, preferably less than
1.33 g/cm.sup.3; f) a coefficient of variation of the maximum
tensile strength of .ltoreq.45%; and g) a coefficient of variation
of the elongation upon tearing of .ltoreq.4.5%.
7. A process for the production of bulky polyester filaments, the
process comprising processing the filaments according to claim 6
into bulky threads in a stretch texturing machine at a speed of at
least 500 m/min. and a stretching ratio of at least 1:1.35.
8. Bulky polyester SET filaments having a resistance to tearing of
more than 26 cN/tex and an elongation upon tearing of more than
36%.
9. Bulky polyester HE filaments having resistance to tearing of
more than 26 cN/tex and elongation upon tearing of more than
30%.
10. Bulky polyester SET filaments made according to the process of
claim 7.
11. Bulky polyester HE filaments made according to the process of
claim 7.
12. The process according to claim 1, wherein the preoriented
polyester filaments comprises at least 90 weight % (relative to the
total weight of the polyester filaments) PTMT.
13. The preoriented polyester filaments according to claim 6, the
density is less than 1.33 g/cm.sup.3.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/263,013, filed Jan. 19, 2001.
BACKGROUND OF THE IVNENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a process for the spinning
and spooling of preoriented polyester filaments using spinning
additives, which filaments comprise (in the amount of at least 90
weight % in relation to the total weight of the polyester filament)
polybutylene terephthalate (PBT) and/or polytrimethylene
terephthalate (PTMT), preferably of PTMT, as well as the
preoriented polyester filaments obtained by the process. In
addition, the present invention relates to a process for the
stretch texturing of the spun and spooled polyester filaments, as
well as the bulky polyester filaments obtained by means of stretch
texturing.
[0004] 2. Summary of the Related Art
[0005] The production of continuous polyester filaments in a
two-stage process, particularly polyethylene terephthalate (PET)
filaments, is known. In this process, smooth, preoriented filaments
are spun and spooled during a first stage and then, during a second
stage, stretched into finished form and thermofixed, or else
stretch-textured into bulky filaments.
[0006] The book "Synthetic Fibers" by F. Fourn (1995), published by
Hanser-Verlag, Munich, provides an overview of this. Only the
production of PET fibers is described by Fourn, and no closed
spinning technology is explained but, instead, this is only an
overview in which the most general characteristics are
described.
[0007] The technical production of various spinable polymers, such
as polypropylene, polyamides, polyesters, among others, is the
object of application document DE-OS 38 19 913. Only the production
of PET fibers is described in the examples, as it can be derived at
the temperature at which the polymer is processed.
[0008] In the production of continuous polytrimethylene
terephthalate (PTMT) or polybutylene terephthalate (PBT) filaments,
the problem exists that preoriented filaments have a considerable
tendency to shrink during storage at ambient temperature, both
immediately after the spinning and upon the spooling, as well as
several hours after the spooling, leading to a shortening of the
fibers. The body of the spool is thereby compressed so that, in the
extreme case, a tight shrinking of the coil forming body on the
spooling mandrel arises, and the coil forming body can no longer be
removed. Furthermore, a so-called saddle unit with hard edges and
an indented middle part forms the coil forming body. By that means,
the characteristic textile values of the filaments, such as the
uster, for example, become unevenly stronger, and there are
unspooling problems during the processing of the coils. Such types
of problems do not appear during the processing of PET fibers.
[0009] Furthermore, it has been observed that, in contrast to PET
filament, preoriented PBT and PTMT filaments show increased signs
of aging during storage. A structural hardening appears, which
leads to such a great reduction of the processing shrinkage that a
subsequent crystallization can be observed. Such types of PBT and
PTMT filaments are only conditionally suitable for further
processing and lead to errors in the stretch texturing as well as
to a significant reduction of the resistance to tearing of the
textured thread.
[0010] These differences between PET on the one hand and PBT and
PTMT on the other are attributable to differences in structures and
properties such as are presented, for example, in Chemical Fibers
Int., page 53, volume 50 (2000) and were the theme of the 39th Int.
Man-Made Fibers Congress, from Sep. 13 to 15, 2000, in Dornbirn. It
is thus assumed that different chain formations are responsible for
the differences in properties.
[0011] First attempts to solve these problems were described in the
patent application WO 99/27168 and the European patent EP 0 731 196
B1. WO 99/27618 discloses a polyester fiber which consists of at
least 90 weight % of polytrimethylene terephthalate and has a
processing shrinkage of between 5% and 16%, as well as an
elongation upon tearing of 20% to 60%. The production of the
polyester fibers described in WO 99/27168 is carried out by means
of spinning and stretching. In this, spinning removal speeds of a
maximum of 2100 m/min. are stated. The process is uneconomical
because of the low spinning speed. Furthermore, the polyester
fibers that are obtained are, as the characteristic constants
indicated show, strongly crystalline and, consequently, are
suitable for stretch texturing processes only to limited
degree.
[0012] European patent EP 0 731 196 B1 claims a process for
spinning, stretching, and spooling of synthetic thread in which the
thread is, after the stretching but before the spooling, subjected
to heat treatment to reduce the tendency to shrink. Usable
synthetic fibers also include polytrimethylene terephthalate
fibers. In accordance with EP 0 731 196 B1, the heat treatment
takes place by closely guiding the synthetic thread (essentially
without contact) along a longitudinally extended heating surface.
The use of a heat treatment makes the process more expensive and
additionally results in synthetic threads with high crystallinity.
Such threads are suitable for stretch texturing only to a limited
extent.
[0013] Stretch texturing of preoriented polytrimethylene
terephthalate filaments at texturing speeds of 450 m/min. and 850
m/min. is described in the article by Dr. H. S. Brown and H. H.
Chuah, "Texturing of textile filament yarns based on
polytrimethylene terephthalate" in Chemical Fibers International,
Volume 47, February 1997, pages 72-74. According to this
disclosure, the lower texturing speed of 450 m/min. is better
suited for polytrimethylene terephthalate filaments since fibers
with better material properties are obtained. The resistance to
tearing of the polytrimethylene terephthalate fibers is stated as
26.5 cN/tex (texturing speed of 450 m/min.) or 29.15 cN/tex
(texturing speed of 850 m/min.), respectively, and the elongation
upon tearing at 38.0% (texturing speed of 450 m/min.) or 33.5%
(texturing speed of 850 m/min.), respectively.
[0014] WO 01/04393 describes PTMT filaments having a processing
shrinkage in the range of 3 to 40%. This value is determined
immediately after the production of the filaments, however. As the
appended FIGURE shows, this value drops to below 20% under normal
conditions after a storage time of 4 weeks.
[0015] The processing shrinkage is a measure of the processability
and degree of crystallization of the fibers. The fibers described
in WO 01/04393 have plastics with a higher degree of
crystallization. The processing of such fibers is significantly
worse and only at lower stretching ratios and/or lower texturing
speeds.
SUMMARY OF THE INVENTION
[0016] The present invention provides a process for spinning and
spooling preoriented polyester filaments that comprise, by at least
90 weight % in relation to the total weight of the filaments, PBT
and/or PTMT, which process simplifies the production and the
spooling of preoriented polyester filaments. In particular, the
preoriented polyester filaments produced by the process of the
invention have values for elongation upon tearing in the range of
90% to 165%, a high uniformity in relation to the characteristic
filament values, as well as a low degree of crystallization.
[0017] The process of the invention for spinning and spooling
preoriented polyester filaments can be carried out on a large
technical scale and in an economical manner. The process in
accordance with the invention permits the highest possible removal
speeds, preferably greater than 2200 m/min., and high thread
weights, of more than 4 kg, on the body of the spool.
[0018] The process of the present invention improves the
storability of the preoriented polyester filaments thereby
produced. These preoriented polyester filaments can be stored for a
longer period of time than prior art filaments (e.g., 4 weeks).
Compression of the spool body during storage, particularly a firm
shrinking of the coil forming body onto the spooling mandrel, as
well as the formation of a saddle with hard edges and indented
middle part, is prevented, to the extent possible, so that no
unspooling problems occur during the processing of the coils.
[0019] In accordance with the invention, the preoriented polyester
filaments can be further processed in a simple way in an extension
or stretch texturing process, particularly at high texturing
speeds, preferably greater than 450 m/min. The filaments obtained
by means of stretch texturing have outstanding material properties,
such as a high resistance to tearing of more than 26 cN/tex, for
example, as well as a high elongation upon tearing of more than 30%
in the case of HE-filaments, or more than 36% for SET
filaments.
[0020] All patents, patent applications, and other publications
recited herein are incorporated by reference in their entirety. In
the event of an inconsistency between the present disclosure and
the disclosures incorporated by reference, the present disclosure
is relied upon herein.
BRIEF DESCRIPTION OF THE DRAWING
[0021] The FIGURE describes the change of the processing shrinkage
for three PTMT-POY spools in dependence on the storage time under
normal climate conditions. In this, the change of the POY
processing shrinkage was investigated for three spools with
different starting values over the storage time at normal climate
conditions. Spools no. 16 and 17, with a high initial value
>40%, show, after 4 weeks, a processing shrinkage above 30%,
preferably above 40%. In the event that the initial value of the
processing shrinkage is greater than 40%, however, then spool 18
shows that this drops below the critical value of 30% after 4 weeks
of storage time.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention comprises a process for producing and
spooling preoriented polyester filaments that comprise polybutylene
terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT)
(preferably of PTMT) in an amount that is at least 90 weight % in
relation to the total weight of the polyester filaments, the
process comprising:
[0023] a) spinning the filaments in a spinning nozzle with a
spinning delay in the range of 70 to 500;
[0024] b) passing the filaments, immediately after exiting from the
spinning nozzle, through a cooling delay zone from 30 mm to 200 mm
in length;
[0025] c) cooling the filaments to below the PBT or PTMT
solidification temperature;
[0026] d) bundling the filaments at a distance of between 500 mm
and 2500 mm from the lower side of the nozzle;
[0027] e) setting the tension of the thread in front of and behind
removal galettes to between 0.05 cN/dtex to 0.20 cN/dtex;
[0028] f) spooling the thread with a tension of between 0.025
cN/dtex to 0.15 cN/dtex and spooling speed of between 2200 m/min.
and 6000 m/min.;
[0029] h) mixing in a polyester expansion-promoting agent in an
amount of 0.05 weight % to 2.5 weight % (in relation to the total
weight of the filament of additive polymer).
[0030] With the process of the present invention we have been able,
in a manner that was simply not foreseeable, to make polyester
filaments with outstanding properties, even after a storage for 4
weeks under normal conditions. No significant worsening of the
uniformity values of the thread resulting from aging or shrinking
of the spun fiber coil on the spool is observed.
[0031] The process in accordance with possesses, at the same time,
a series of additional advantages. These include, among others, the
following:
[0032] The process in accordance with the invention can be
conducted simply, on a large scale, and economically. In
particular, the process permits spinning and spooling at high
removal speeds of at least 2200 m/min., as well as production of
high thread weights (of more than 4 kg) on the spool body.
[0033] Through the use of spinning additives, removal speeds of up
to 6000 m/min. can be achieved. Because of this, the equipment can
be operated in a particularly economic manner.
[0034] The preoriented polyester filaments obtained by means of the
process consequently can be further processed simply, on a large
scale, and in an economical manner, in either an extension or a
stretch texturing process. The texturing can thereby be carried out
at speeds of greater than 450 m/min.
[0035] Because of the high uniformity of the preoriented polyester
filaments obtained through the process of the invention, it is
possible to obtain a good spool design simply, which makes possible
uniform and nearly error-free surface coloring, as well as a
further processing of the preoriented polyester filaments.
[0036] Stretch textured filaments of the invention have high
resistance to tearing (>26 cN/tex) as well as high elongation
upon tearing, >30%) for HE filaments and >36% for SET
filaments.
[0037] The present invention comprises a process of producing and
spooling preoriented polyester filaments that comprise polybutylene
terephthalate (PBT) and/or polytrimethylene terephthalate (PTMT) in
an amount of at least by 90 weight % in relation to the total
weight of the polyester filament. Polybutylene terephthalate (PBT)
and polytrimethylene terephthalate (PTMT) are known in the art.
Polybutylene terephthalate (PBT) can be obtained by
polycondensation of terephthalic acid with equimolar quantities of
1,4-butanediol, and polytrimethylene terephthalate can be obtained
by polycondensation of terephthalic acid with equimolar quantities
of 1,3-propanediol. Mixtures of both polyesters are also
contemplated for use in the invention. In accordance with the
invention, PTMT is preferred.
[0038] The polyesters can be both homo- as well as co-polymers.
Especially preferred as copolymers are those that contain, in
addition to recurring PTMT and/or PBT units, an additional amount
of up to 15 mol. %, in relation to all monomer units of the
polyester, monomers of normal polyester comonomers, such as
ethylene glycol, diethylene glycol, triethylene glycol,
1,4-cyclohexanedimethanol, polyethylene glycol, isopthalic acid,
and/or adipinic acid, for example. Within the framework of the
present invention, however, polyester homopolymers are
preferred.
[0039] Polyesters in accordance with the invention can contain
normal quantities of additional additive substances as admixtures,
such as catalysts, stabilizers, antistatic agents, antioxidants,
flame retarding agents, colorants, colorant absorption modifiers,
light stabilizers, organic phosphites, optical brighteners, and
matting agents. The polyesters preferably contain from 0 to 5
weight % of additives, in relation to the total weight of the
filament.
[0040] Furthermore, polyesters of the invention can also contain a
slight portion of branching components, preferably up to 0.5 weight
% in relation to the total weight of the filament. The branching
components include, among others, polyfunctional acids, such as
trimellitic acid, pyromellitic acid, or tri- to hexavalent
alcohols, such as trimethylolpropane, pentaerythrite,
dipentaerythrite, glycerin, or corresponding hydroxy acids.
[0041] In the framework of the present invention, 0.05 weight % to
2.5 weight % of additive polymers (relative to the total weight of
the filament), are mixed into the PBT and/or PTMT as
expansion-promoting agents. Additive polymers that are particularly
suitable in accordance with the invention include the polymers
and/or copolymers chosen from among the following:
[0042] 1. A copolymer comprising the following monomer units:
[0043] A=acrylic acid, methacrylic acid, or CH.sub.2.dbd.CR--COOR',
whereby R is --H or a --CH.sub.3 group, and R' is a C.sub.1-15alkyl
radical or a C.sub.5-12 cycloalkyl radical or a C.sub.6-14 aryl
radical;
[0044] B=styrol or C.sub.1-3-alkyl-substituted styrols;
[0045] wherein the copolymer consists of 60 to 98 weight % of A and
2 to 40 weight % of B, preferably 83 to 98 weight % of A and 2 to
17 weight % of B and, particularly preferably, from 90 to 98 weight
% of A and 2 to 10 weight % of B (total=100 weight %);
[0046] 2. A copolymer comprising the following monomer units:
[0047] C=styrol or C.sub.1-3-alkyl-substituted styrols;
[0048] D=one or more monomers of Formula I, II, or III: 1
[0049] wherein R.sup.1, R.sup.2, and R.sup.3 are each independently
--H, a C.sub.1-15-alkyl radical, a C.sub.6-14-aryl radical, or a
C.sub.5-12 cycloalkyl radical; and
[0050] wherein the copolymer comprises from 15 to 95 weight % of C
and from 2 to 80 weight % of D, preferably from 50 to 90 weight %
of C and from 10 to 50 weight % of D, and, particularly preferably,
from 70 to 85% of C and from 15 to 30 weight % of D, whereby the
total of C and D together is 100 weight %;
[0051] 3. A copolymer comprising the following monomer units:
[0052] E=Acrylic acid, methacrylic acid, or CH.sub.2.dbd.CR--COOR',
whereby R is an H atom or a CH.sub.3 group and R' is a
C.sub.1-15-alkyl radical or a C.sub.5-12-cycloalkyl radical or a
C.sub.6-14-aryl radical;
[0053] F=Styrol or C.sub.1-3-alkyl-substituted styrols;
[0054] G=One or more monomers of the formulas I, II, or III: 2
[0055] wherein R.sup.1, R.sup.2, and R.sup.3 are each one H atom or
a C.sub.1-15-alkyl radical or a C.sub.6-14-aryl radical or a
C.sub.5-12-cycloalkyl radical;
[0056] H=one or more ethylenic unsaturated monomers, which can be
copolymerized with E and/or with F and/or G, from the group which
consists of .A-inverted.-methylstyrol, vinylacetate, acrylic acid
esters, methacrylic acid esters which are different from E, vinyl
chloride, vinylidene chloride, halogen-substituted styrols, vinyl
ethers, isopropenyl ethers, and dienes;
[0057] wherein the copolymer consists of from 30 to 99 weight % of
E, from 0 to 50 weight % of F, from >0 to 50 weight % of G, and
from 0 to 50 weight % of H, preferably from 45 to 97 weight % of E,
from 0 to 30 weight % of F, from 3 to 40 weight % of G, and from 0
to 30 weight % H and, particularly preferably, from 60 to 94 weight
% of E, from 0 to 20 weight % of F, from 6 to 30 weight % of G, and
from 0 to 20 weight % of H, whereby the total of E, F, G, and H
together yields 100 weight %.
[0058] 4. A polymer from the following monomer unit: 3
[0059] wherein R.sup.1 and R.sup.2 are substituents consisting of
the optional atoms C, H, O, S, P and halogen atoms, and the total
of the molecular weight of R.sup.1 and R.sup.2 is at least 40.
Examples of such monomers are: acrylic acid, methacrylic acid, and
CH.sub.2.dbd.CR--COOR', whereby R is an H atom or a CH.sub.3 group,
and R' is a C.sub.1-15 alkyl radical or a C.sub.5-12-cycloalkyl
radical or a C.sub.6-14-aryl radical, as well as styrol and
C.sub.1-3-alkyl-substituted styrols.
[0060] Specific details for the production of these substances are
described in WO 99/07 927.
[0061] In the framework of the invention, additive polymers and/or
copolymers in the form of bead polymers, the particle size of which
lies within a particularly favorable range, are particularly
preferred. Preferably, the additive polymers and/or copolymers that
are to be used in accordance with the invention, such as by mixing
into the melts of the fiber polymers, for example, are present with
an average diameter of 0.1 to 1.0 mm. Larger or smaller beads or
granulates can also be used, however. The additive polymers and/or
copolymers can also be contained in chips of the matrix polymer, so
that a measured addition can be dispensed with.
[0062] Furthermore, additive polymers and/or copolymers that are
amorphous and insoluble in the polyester matrix are preferred.
Preferably, they have a glass transition temperature from 90 to
200.degree. C., whereby the glass transition temperature is
determined in a known manner, preferably by means of differential
scanning calorimetry. Additional details can be derived from the
state of the art, such as the publication WO 99/07927, for
example.
[0063] Preferably, the additive polymer and/or copolymer is
selected in such a manner that the ratio of the melt viscosities of
the additive polymer and/or copolymer and of the matrix polymer is
0.8:1 to 10:1, preferably from 1.5:1 to 8:1. The melt viscosity is
measured, in the known manner, by means of an oscillation rheometer
at an oscillation frequency of 2.4 Hz and at a temperature which is
equal to the melt temperature of the matrix polymer plus 28.degree.
C. For PTMT, the melt viscosity is measured at a temperature of
about 255.degree. C. Additional details can, in turn, be derived
from the publication WO 99/07927.
[0064] The melt viscosity of the additive polymer and/or copolymer
is preferably higher than that of the matrix polymer, and it has
been shown that the choice of a specific range of viscosity for the
additive polymer and/or copolymer, and the choice of the viscosity
ratio, contribute to the optimization of the characteristics of the
thread that is produced. In one optimized viscosity ratio, one can
minimize quantity of additive polymer and/or copolymer added,
resulting in a more economical process. The polymer mixture to be
spun preferably contains from 0.05 to 2.5 weight %, particularly
preferably 0.25 to 2.0 weight %, of additive polymer and/or
copolymer.
[0065] Through a favorable choice of viscosity ratio, a narrow
distribution of additive polymer and/or copolymer particle sizes in
the polymer matrix is achieved with the desired fibril structure of
the additive polymer and/or copolymer in the thread. The glass
transition temperature of the additive polymer and/or copolymer,
which is high in comparison with the matrix polymer, ensures a
rapid solidification of this fibril structure in the spinning
thread. The maximum particle sizes of the additive polymer and/or
copolymer, immediately after exiting from the spinning nozzle, are
approximately 1000 nm, while the average particle size is 400 nm or
less. After the spinning delay of the thread, the favorable fibril
structure (containing at least 60 weight % of the additive polymer
and/or copolymer in the form of fibrils) is achieved with lengths
in the range from 0.5 to 20 .mu.m and diameters in the range from
0.01 to 0.5 .mu.m.
[0066] The polyesters that are usable in the invention are,
preferably, thermoplastically formable and can be spun and spooled
into filaments. Polyesters that have a limiting viscosity number in
the range from 0.70 dl/g to 0.95 dl/g are particularly
advantageous.
[0067] A polymer melt, for example, can be removed directly from
the end reactor of a polycondensation equipment, or else produced
from solid polymer chips in a melt extruder.
[0068] The spinning additive can be added in to the matrix polymer,
in the known manner, by means of measured addition in either molten
or solid form, distributed homogenously, and dispersed into fine
particles. A device in accordance with DE 100 22 889 can be used
advantageously.
[0069] In the process of the invention, the melt or mixture of
melts of the polyester is pressed into nozzle assemblies by means
of a spinning pump at constant rotational speed adjusted by known
means in such a manner that the desired thread titer is achieved.
The melt is then extruded through the nozzle apertures of the
nozzle plate of the assembly into molten filaments.
[0070] The melts can be produced in an extruder from polymer chips,
for example, whereby it is particularly favorable to dry the chips
in advance to a water content of .ltoreq.30 ppm, particularly to a
water content of .ltoreq.15 ppm.
[0071] The temperature of the melt, which is designated in a
general manner as the spinning temperature and measured in front of
the spinning pump, depends upon the melting point of the polymer or
mixture of polymers used. It preferably lies in the range stated in
Formula 1:
[0072] Formula 1:
T.sub.m+15.degree. C..ltoreq.T.sub.Sp.ltoreq.T.sub.m+45.degree.
C.;
[0073] in which:
[0074] T.sub.m: Melting point of the polyester [.degree.C];
[0075] T.sub.Sp: Spinning temperature [.degree.C].
[0076] The specified parameters serve to limit the hydrolytic
and/or thermal reduction of the viscosity, which should suitably be
as low as possible. Within the framework of the present invention,
a reduction of viscosity by less than 0.12 dl/g, particularly by
less than 0.08 dl/g, is highly desirable.
[0077] The homogeneity of the melt has a direct influence on the
properties of the spun filaments. It is thus preferable to use a
static mixer with at least one element that is installed after the
spinning pump for the homogenization of the melts.
[0078] The temperature of the nozzle plate, which is dependent upon
the spinning temperature, is controlled by means of so-called
associated heating. A spinning bar heated with "Diphyl", or with
additional convection or radiation heaters, for example, may
contribute to associated heating. The temperature of the nozzle
plates is usually around that of the spinning temperature.
[0079] One can Increase the temperature of the nozzle plate by
reducing the pressure in the nozzles assembly. Known derivations,
such as, for example, that by K. Riggert, "Progress in the
production of polyester tire cord thread" in Chemifasern [Chemistry
fibers], 21, page 379 (1971), describe a temperature increase of
approximately 4.degree. C. per 100 bar reduction of pressure.
[0080] In addition, it is possible to control the nozzle pressure
through the application of loose filter media, particularly steel
sand with an average grain size of between 0.10 mm and 1.2 mm,
preferably between 0.12 mm and 0.75 mm, and/or circular filter
blanks with a fineness of .ltoreq.40:, which can be produced from
metal fabrics or membranes.
[0081] In addition, pressure drop in the nozzle aperture
contributes to the overall pressure. The nozzle pressure is
preferably set between 80 bar and 450 bar, particularly between 100
bar and 250 bar.
[0082] The spinning delay i.sub.Sp--that is to say, the quotient of
the removal speed and the injection spraying speed--is computed, in
accordance with U.S. Pat. No. 5,250,245 by means of Formula 2, with
the density of the polymer or mixture of polymers the diameter of
the nozzle aperture, and the titer of the individual filament:
[0083] Formula 2:
i.sub.Sp=2.25.multidot.10.sup.5.multidot.(.delta..multidot..pi.).multidot.-
D.sup.2(cm)/dpf(den);
[0084] in which:
[0085] .delta.: Density of the melt [g/cm.sup.3]; for PTMT=1.12
g/cm.sup.3;
[0086] D: Diameter of the nozzle aperture [cm];
[0087] dpf: Titer of the individual filament [den].
[0088] Within the framework of the present invention, the spinning
delay is between 70 and 500, preferably between 100 and 250.
[0089] The length/diameter ratio of the nozzle aperture is
preferably between 1.5 and 6, especially between 1.5 and 4.
[0090] The extruded filaments pass through a cooling delay zone.
This is configured as a resilience zone directly below the assembly
of nozzles, inside of which the filaments exiting from the nozzle
apertures are protected against the direct effect of cooling gas
and are delayed for deceleration or for cooling. An active portion
of the resilience is provided in the form of an off-set of the
assembly of the nozzles into the spinning bar, so that the
filaments are surrounded by heated partitions. A passive portions
is formed of insulation layers and unheated framework. The lengths
of the active resilience lie between 0 to 100 mm and those of the
passive portion lie between 20 to 120 mm, whereby a total length of
30 to 200 mm, preferably 30 to 120 mm, is maintained.
[0091] As an alternative to an active resilience, a follow-up
heater can be attached below the spinning bar. In contrast to the
active resilience, this zone with cylindrical or rectangular
cross-section then has heating that is independent of the spinning
bar.
[0092] In radial porous cooling systems concentrically surrounding
the thread, cooling delay can be achieved with the help of
cylindrical coverings.
[0093] The filaments are subsequently cooled to temperatures below
their solidification temperature. In accordance with the invention,
"solidification temperature" means that temperature at which the
melt makes a transition to a solid aggregate.
[0094] In the framework of the present invention, it has proven to
be particularly suitable to cool the filaments to a temperature at
which they are essentially no longer sticky. Cooling of the
filaments to temperatures below their crystallization temperature,
particularly to temperatures below their glass transition
temperature, is particularly advantageous.
[0095] Means for cooling the filaments are known in the art. In
accordance with the invention, the use of cool gases, particularly
cooled air, have proven particularly valuable. The cooling air
preferably is from 12.degree. C. to 35.degree. C., particularly
from 16.degree. C. to 26.degree. C. The speed of the cooling air
advantageously lies within the range from 0.20 m/sec to 0.55
m/sec.
[0096] Individual thread systems, which consist of individual
cooling tubes with a perforated partition wall, for example, can be
used for cooling the filaments. Cooling each individual filament is
achieved by means of actively supplying cooling air, or also by
using the self-suctioning effect of the filaments. As an
alternative to individual tubes, known systems that involve
transverse blowing can also be used.
[0097] One particular configuration of the cooling and delay area
consists of supplying the filaments exiting from the delay zone
with cooling air in a zone with a length in the range from 10 to
175 cm, preferably in a zone with a length in the range of 10 to 80
cm. For filaments with a titer upon spooling of .ltoreq.1.5 dtex
per filament, zone length in the range of from 10 to 40 cm is
suitable, and a length of zone in the range from 20 to 80 cm is
particularly well suited for filaments with a titer between 1.5 and
9.0 dtex per filament. Subsequently, the filaments and the air
accompanying them are guided in common through a channel of reduced
cross-section, whereby the ratio of the air speed to the thread
speed of 0.2 to 20:1, preferably 0.4 to 5:1, is set during the
removal by controlling the cross-sectional taper and dimension in
the machine direction of the thread.
[0098] After cooling the filaments to temperatures below the
solidification temperature, they are bundled into a thread. The
distance of the bundling from the lower side of the nozzle suitable
for use in the invention can be determined by methods known in the
art for on-line measurement of thread speed and/or temperature,
such as, for example, by means of a laser/doppler anemometer from
firm TSI/Germany, or an infrared camera from the manufacturer
Goratec/Germany, type IRRIS 160. This is 500 to 2500 mm, preferably
500 to 1800 mm. Filaments with a titer of .ltoreq.3.5 dtex are
thereby preferably bundled at a small distance of .ltoreq.1500 mm,
while thicker filaments are preferably bundled at a greater
distance.
[0099] In the framework of the present invention, it is suitable
that all surfaces that come into contact with the spun filament are
preferably low-friction materials. Formation of thread ends can be
thoroughly avoided in this way, so that higher-valued filaments are
obtained. Low-friction surfaces, such as "TriboFil" from the firm
Ceramtec/Germany, have proven themselves to be particularly well
suited for this purpose.
[0100] Bundling of the filaments is carried out in an oiling unit
that supplies the desired quantity of spinning preparation to the
thread. One particularly suitable oiling unit is characterized by
an intake part, a thread channel with an oil entrance aperture, and
a discharge part. The intake part is expanded in a funnel shape, so
that contact with the filaments, which are still dry, is prevented.
The striking point of the filaments lies inside the thread channel
behind the inflow feed of the preparation. The thread channel and
oil inlet aperture are adjusted in width to the thread titer and
the number of filaments. Apertures and widths in the range of 1.0
mm to 4.0 mm have proven particularly valuable. The discharge part
of the oiling device is designed as a blending segment, which
preferably has oil reservoirs. Such types of oiling devices are
commercially available and can be purchased from the firm
Ceramtec/Germany, or Goulston/USA, for example.
[0101] Uniformity application of oil can be of great importance in
the process of the invention. Uniformity can be determined, for
example, by means of a Rossa measuring device as described in the
journal "Chemiefasern/Textilindustrie" [Chemical Fibers/Textile
Industry], 42/94, November 1992, on page 896. Preferably, in such a
process, values for the standard deviation of the oil application
of <90 units, and preferably <60 units, are obtained. Values
for the standard deviation of the oil application of <45 digits,
particularly of <30 digits, are particularly preferred in
accordance with the invention. A standard deviation of 90 units or
45 units, respectively, corresponds to approximately 6.2% or 3.1%,
respectively, of the coefficient of variation.
[0102] In the framework of the present invention, it has proven to
be particularly advantageous to design lines and pumps for the
prevention of gas bubbles in a self-degassing manner, since these
can lead to a considerable oscillation of the oil application.
[0103] In accordance with the invention, interweaving of the
filaments before spooling the thread is particularly preferred. In
this, nozzles with closed thread channels have proven to be
particularly well suited, since hooking of the thread in the
insertion slot are avoided in such systems, even with low thread
tension and high air pressure. The interweaving nozzles are
preferably positioned between galettes, whereby the thread
discharge tension is regulated by means of different speeds of the
intake and discharge galette. These should not exceed 0.20 cN/dtex,
but primarily have values between 0.05 cN/dtex and 0.15 cN/dtex.
The pressure of the entangling air thereby lies between 0.5 and 5.5
bar at spooling speeds up to 3500 m/min. at a maximum of 3.0
bar.
[0104] Preferably, node numbers of at least 10 n/m are set. In
this, maximum aperture lengths of less than 100 cm and values of
the variation coefficients of the node number of below 100% are of
particular interest. Upon the use of air pressures above 1.0 bar,
node numbers of .gtoreq.15 n/m, which are characterized by a high
uniformity, are advantageously achieved, whereby the coefficient of
variation is less than or equal to 70%, and the maximum length of
aperture is 50 cm. In actual practice, systems of the type LD from
the firm Temco/Germany, the double system from the firm Slack &
Parr/USA, or nozzles of the type Polyjet from the firm Heberlein,
have proven to be particularly well suited.
[0105] The circumferential speed of the galette unit is termed the
removal speed. Additional galette systems can be applied before the
thread is rolled up within the coil unit onto coil forming bodies
(spools) and casing tubes.
[0106] Stable, error-free thread coil forming bodies are essential
for an error-free removal of the thread, as well as for a further
processing that is as free of errors as possible. Thus, in the
framework of the present process, a spooling tension in the range
from 0.025 cN/dtex to 0.15 cN/dtex, preferably in the range of 0.03
cN/dtex to 0.08 cN/dtex, is applied.
[0107] One important parameter of the process in accordance with
the invention is the adjustment of the tension of the thread in
front of and between the removal galettes. This tension, as is
known in the art, essentially composed of the actual orientation
tension in accordance with Hamana, the frictional stress on the
thread guides and the oiling device, and the thread/air friction
stress. Within the framework of the present invention, the tension
of the thread in front of and between the removal galettes is in
the range from 0.05 cN/dtex to 0.20 cN/dtex, preferably between
0.08 cN/dtex and 0.15 cN/dtex.
[0108] Insufficient tension (<0.05 cN/dtex) fails to yield the
desired level of preorientation. If the tension exceeds 0.20
cN/dtex, it triggers a memory effect upon spooling and storage of
the spools, which leads to the worsening of the thread's
properties.
[0109] In accordance with the invention, the tension is controlled
through the distance of the oiling device from the nozzle and the
friction surfaces, and the gap length between the oiling device and
the removal galette. This length of gap advantageously is not more
than 6.0 m, preferably less than 2.0 m, whereby the spinning
machine and the removal machine are positioned, by means of
parallel construction, in such a manner that a straight course of
the threads is guaranteed.
[0110] The conditioning time of the thread between the bundling
point and the spooling are described by means of geometrical
parameters. The relaxation that is proceeding rapidly during this
time influences the quality of the spool design.
[0111] The conditioning time, as defined in such manner, is
preferably selected between 50 and 200 ms.
[0112] In accordance with the invention, the spooling speed of the
POY's is between 2200 m/min. and 6000 m/min. A speed of between
2500 m/min. and 6000 m/min. is preferably chosen. Particularly
preferably, the polymer mixtures are spooled at speeds in the range
from 3500 m/min. to 6000 m/min.
[0113] In an advantageous manner, the temperature in the vicinity
of the thread coil is set to .ltoreq.45.degree. C., particularly
between 12 and 35.degree. C., and the relative humidity is set to
40 to 85%. Furthermore, it is suitable to store the POY spools for
at least 4 hours at 12 to 35.degree. C. and a relative humidity of
40 to 85% before further processing.
[0114] After 4 weeks of storage under normal conditions, the
filament in accordance with the invention has:
[0115] a) an elongation upon tearing of between 90 and 165%,
preferably between 90 and 135%;
[0116] b) a processing shrinkage of at least 30%, preferably
.gtoreq.40%;
[0117] c) a normal uster below 1.1%, preferably less than 0.9%;
[0118] d) a double refraction of between 0.030 and 0.058;
[0119] e) a density of less than 1.35 g/cm.sup.3, preferably less
than 1.33 g/cm.sup.3;
[0120] f) a coefficient of variation of the maximum tensile
strength of .ltoreq.4.5%, preferably .ltoreq.2.5%; and
[0121] g) a coefficient of variation of the elongation upon tearing
of .ltoreq.4.5%, preferably .ltoreq.2.5%.
[0122] The term "normal conditions" is known in the art and is
defined by the norm DIN 53802. At "normal conditions" in accordance
with DIN 53802, the temperature is 20.+-.2.degree. C. and the
relative humidity 65.+-.2%.
[0123] In the framework of the present invention, it is
additionally advantageous that the processing shrinkage when
measured immediately after the spooling is between 50 and 65% and,
after 4 weeks of storage at normal conditions, at least 30%,
preferably .gtoreq.40%. It has been surprisingly shown that POY
spools produced in such a manner can be further processed in an
outstanding manner.
[0124] Processes for the determination of the material properties
are best known to those skilled in the art. They can be found in
the technical literature. Although most parameters can be
determined in a variety of ways, the following methods have, within
the framework of the present invention, proven to be particularly
suitable for the determination of the characteristic values of the
filament.
[0125] The intrinsic viscosity is measured at 25.degree. C. in the
capillary viscosimeter from the firm Ubbelohde and computed in
accordance with a known formula. A mixture of
phenol/1.2-dichlorobenzol is used as a solvent in the weight ratio
of 3:2. The concentration of the solution is 0.5 g polyester to 100
ml of solution.
[0126] A DSC calorimeter from the firm Mettler is used to determine
the melting point and the temperature of crystallization and glass
transition. In this, the sample is thereby first heated to
280.degree. C. and melted, and then suddenly chilled. The DSC
measurement is carried out in the range from 20.degree. C. to
280.degree. C., with a heating rate of 10 K/min. The temperature is
determined by the processor.
[0127] The density of the filaments is determined in a
density/gradient column at a temperature of 23.+-.0.1.degree. C.
n-heptane (C.sub.7H.sub.16) and tetrachloromethane (CCI.sub.4) are
used as the reagent. The result of the density measurement can be
used to compute the degree of crystallization, since the density of
the amorphous polyester D.sub.a and the density of the crystalline
polyester D.sub.k are taken as the basis. The corresponding
computation is known in the art; for example, the following is
valid for PTMT: D.sub.a=1.295 g/cm.sup.3 and D.sub.k=1.429
g/cm.sup.3.
[0128] The titer is determined in the known manner by means of a
precision reeling machine and a weighing device. The pre-stressing
is suitably 0.05 cN/dtex for preoriented filaments (POY's), and to
0.2 cN/dtex for textured thread (DTY).
[0129] The resistance to tearing and the elongation upon tearing
are determined in a Statimat measuring device with the following
conditions: the clamping length is 200 mm for POY or 500 mm for
DTY; the measuring speed is 2000 mm/in. for POY or 1500 mm/min. for
DTY; and the pre-stressing is 0.05 cN/dtex for POY or 0.2 cN/dtex
for DTY. Resistance to tearing is determined by dividing the values
of the maximum tensile strength by the titer, while the elongation
upon tearing is evaluated at the maximum load.
[0130] To determine the processing shrinkage, strands of filaments
are treated, in a tension-free manner, in water at 95.+-.1.degree.
C. for 10.+-.1 min. The strands are produced by means of a reeling
machine with pre-stressing of 0.05 cN/dtex for POY or of 0.2
cN/dtex for DTY; the measurement of the length of the strands
before and after the temperature treatment is conducted at 0.2
cN/dtex. The processing shrinkage is computed in the known manner
from the differences in lengths.
[0131] The determination of the double refraction is carried out in
accordance with the procedure described in DE 19 519 898.
[0132] The characteristic wrinkling values of the textured
filaments are measured, in accordance with DIN 53840, Part 1, by
means of the Texturmat devices from the firm Stein/Germany, at the
development temperature of 120.degree. C.
[0133] The normal uster values are determined with the 4-CX Uster
Tester and stated as uster % values. At a test speed of 100 m/min.,
the test time for this is 2.5 min.
[0134] The POY in accordance with the invention can be further
processed simply and can, in particular, be stretch-textured.
Within the framework of the present invention, the stretch
texturing is preferably carried out at a texturing speed of at
least 500 m/min. and particularly preferably at a texturing speed
of at least 700 m/min. The stretching ratio is preferably at least
1:1.35, and particularly at least 1:1.40. Stretch texturing on a
machine of the high-temperature heater type, such as the AFK from
the firm Barmag, for example, has proven to be particularly
suitable.
[0135] Bulky filaments produced in such a manner have a low number
of thread ends and, depending on the surface coloring under
processing conditions with a carrier-free dispersion colorant, have
both an excellent depth of color and a uniformity of color.
[0136] Bulky SET filaments produced in accordance with the
invention preferably have a resistance to tearing of more than 26
cN/tex and an elongation upon tearing of more than 36%. In bulky HE
filaments, which can be obtained without temperature application in
a second heater, the resistance to tearing preferably is >26
cN/tex, and the elongation upon tearing is >30%.
[0137] The pad and elasticity behavior of the filaments in
accordance with the invention is outstanding.
[0138] The invention will be illustrated in the following by means
of examples, without the invention having to be restricted to these
examples.
EXAMPLES 1 to 3
Spinning and Spooling
[0139] PTMT chips with an intrinsic viscosity of 0.93 dl/g, a melt
viscosity of 325 Pa s (measured at 2.4 Hz and 255.degree. C.), a
melting point of 227.degree. C., a crystallization temperature of
72.degree. C., and a glass transition temperature of 45.degree. C.,
were dried in a dry blend mixing dryer at a temperature of
130.degree. C. to a water content of 11 ppm.
[0140] The chips were melted in a 3E4 extruder from the firm
Barmag, so that the temperature of the melt was 255.degree. C.
Different quantities of polymethylmethacrylate of the commercial
type Plexiglas 7N from the firm Rohm GmbH/Germany, which had
previously been dried to a residual moisture of less than 0.1%,
were added into this melt as an expansion-promoting additive.
[0141] The additive polymer was, in addition, melted by means of a
melt extruder and supplied to the feeding device by means of a
toothed wheel dosing pump and supplied there in the direction of
flow with the polyester components by means of an injection nozzle.
In a static mixer from the firm Sulzer, type SMX, having 15
elements and an internal diameter of 15 mm, both of the melts were
homogenously mixed with one another and finely dispersed.
[0142] The melt viscosity of the type Plexiglas 7N was 810 Pa s
(2.4 Hz, 255.degree. C.), whereby the ratio of the additive- and
polyester melt viscosity was 2.5:1.
[0143] 63 g/min. of melt was transported with a residence time of 6
min., and the quantity added into the assembly of nozzles by
measured addition by means of the spinning pump was set in such a
manner that the POY titer was approximately 102 dtex. Different
spooling speeds were set. An element of a static mixer, type HD-CSE
from the firm Fluitec with an internal diameter of 10 mm, was
installed after the spinning pump and before the entrance into the
nozzle assembly. The associated heating units of the product line
and spinning block, which contained the pump and the assembly of
nozzles, were set at 255.degree. C. The assembly of nozzles
contained the filter media steel sand of the grain size 350 to 500
.mu.m at a level of 30 mm, as well as a 20 .mu.m membrane filter
and a 40 .mu.m fabric filter. The melt was extruded through a
nozzle plate 80 mm in diameter with 34 holes 0.25 mm in diameter
and a length of 1.0 mm. The nozzle pressure was approximately 120
to 140 bar.
[0144] The cooling delay zone had a length of 100 mm, whereby 30 mm
were a heated partition wall, and 70 mm were insulation and
unheated framework. Subsequently, the melt threads were cooled off
in a blowing shaft with a transverse current blowing with a blowing
length of 1500 mm. The cooling air had a speed of 0.35 m/sec., a
temperature of 18.degree. C., and a relative humidity of 80%. The
solidification point of the filaments lay at a distance
approximately 800 mm below the spinning nozzle.
[0145] The threads were provided with spinning preparation and
bundled with the help of a thread oiling device at a distance of
1050 mm from the nozzle. The oiling device had a TriboFil surface
and an intake aperture 1 mm in diameter. The quantity of
preparation applied was 0.40% in relation to the weight of the
thread.
[0146] The bundled thread was then conveyed to the spooling
machine. The distance between the oiling device and the first
removal galette was 3.2 m. The conditioning time was between 105
and 140 ms. The pair of galettes was looped around by the thread in
an S-shaped manner. A Temco interweaving nozzle, which was operated
at an air pressure of 1.5 bar, was installed between the galettes.
Corresponding to the adjustment of the speed, the spooling speed of
the winding device of the type SW6 from the firm Barmag was set in
such a manner that the spooling tension of the thread was 5 cN. The
room climate was set at 24.degree. C. at 60% relative humidity, so
that a temperature of approximately 34.degree. C. was set in the
vicinity of the thread coil.
[0147] A significant increase of the productivity was achieved for
all of the quantities of additives that were mixed in. Ten kg
spools, which could be removed from the spool mandrel without any
problem, were produced. The POY threads were distinguished by a
good temporal consistency of the thread characteristics over the
storage time of 4 weeks at a normal climate in accordance with DIN
53802. Immediately after the spinning and spooling, the processing
shrinkage was determined to be within the range of 51 to 54%. The
texture and uniformity of surface coloring were outstanding. The
stretching ratio applied was surprisingly high for the POY speeds
that were used.
[0148] The additional parameters and characteristic values are
summarized in Tables 1 to 4.
1TABLE 1 Experimental parameters Experimental parameters Example 1
Example 2 Example 3 Concentration of [%] 0.5 0.7 1.0 additives
Removal speed [m/min] 3011 3520 4022 Spooling speed [m/min] 3005
3500 4000 Spinning delay 183 182 181 Thread tensions- In front of
galettes (1) [cN] 13 15.5 16 Between galettes (1) - [cN] 12 13 12.5
max. In front of galettes (2) [cN/dtex] 0.13 0.15 0.16 Between
galettes (2)- [cN/dtex] 0.11 0.13 0.12 max. Spooling tension of the
[cN] 6.3 5.9 6.4 thread (1) Spooling tension of the [cN/dtex] 0.062
0.058 0.062 thread (2) (1) Absolute. (2) In relation to the
titer.
[0149]
2TABLE 2 Materials characteristics of the preoriented PTMT
filaments (1). Materials characteristics: Example 1 Example 2
Example 3 Titer [dtex] 102 102.5 103 Resistance to tearing [cN/tex]
20.2 21.8 22.3 Elongation upon tearing [%] 132.7 115.4 98.2 Normal
uster [%] 0.80 0.90 0.94 Processing shrinkage [%] 48 44 38 Double
refraction .multidot. 10.sup.3 .DELTA.n 36 47 51 Density g/cm.sup.3
1.315 1.318 1.320 CV-maximum tensile [%] 1.7 1.5 2.1 strength
CV-elongation upon tearing [%] 1.9 1.9 3.3 CV: Coefficient of
variation. (1): Measured after 4 weeks of storage at normal
conditions.
Stretch Texturing
[0150] The PTMT filament spools were stored in normal climate for
four weeks in accordance with DIN 53802 and then submitted to a
stretch texturing machine from the firm Barmag, type FK6-S-900. The
test parameters of the stretch texturing for the production of
so-called SET filaments are summarized in Table 3, while the
materials characteristics of the resulting bulky SET filaments are
summarized in Table 4.
[0151] The texturing errors were determined by means of the UNITENS
from the firm Barmag, with the following adjustments of range
finding data:
3 UP/LP = 3.0 cN; UM/LM = 6.0 cN.
[0152]
4TABLE 3 Test parameters of the stretch texturing Experimental
parameters Example 1 Example 2 Example 3 Speed [m/min.] 700 700 700
Stretching ratio 1:1.70 1:1.60 1:1.44 D/Y ratio 2.1 2.1 2.1
Temp[erature] - Heater 1 [.degree. C.] 155 155 155 Temp[erature] -
Heater 2 [.degree. C.] 160 160 160 Texturing error [n/10 km] 0 0 0
Tension of the thread F1, in front of unit [cN] 17 18 19 F.sup.2,
behind the unit [cN] 19 21 21 F.sup.2-CV [%] 0.78 0.93 0.89
F.sup.2-CV: Coefficient of variation of F.sup.2.
[0153]
5TABLE 4 Materials characteristics of the stretch-textured
filaments Materials characteristics Example 1 Example 2 Example 3
Titer [dtex] 67 69 79 Resistance to tearing [cN/tex] 26.9 29.6 28.2
Elongation upon tearing [%] 38.6 37.8 38.0 Visual surface coloring
Uniform Uniform Uniform evaluation Wrinkling resistance [%] 84 85
79 Curling [%] 25 24 23
* * * * *