CA1245841A - Heat-durable spun-like fasciated yarn and method for producing the same - Google Patents
Heat-durable spun-like fasciated yarn and method for producing the sameInfo
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- CA1245841A CA1245841A CA000426179A CA426179A CA1245841A CA 1245841 A CA1245841 A CA 1245841A CA 000426179 A CA000426179 A CA 000426179A CA 426179 A CA426179 A CA 426179A CA 1245841 A CA1245841 A CA 1245841A
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Abstract
HEAT-DURABLE SPUN-LIKE FASCIATED YARN AND METHOD FOR
PRODUCING THE SAME
ABSTRACT OF THE DISCLOSURE
A fasciated yarn, consisting of wholly aromatic polyamide fibers, which is excellent in mechanical properties, especially in creep durability in a high temperature atmosphere and is suitably utilized for industrial usage. The yarn can be produced by a method comprising the steps of: stretch-breaking a filament tow of the wholly aromatic polyamide fibers to form a staple fiber bundle and imparting a false-twist to the staple fiber bundle by a vortex while retaining parallelism of the staple fibers composing the bundle, thereby obtaining the fasciated yarn. Structural characteristics of the yarn reside in a mean fiber length in the range of from 150 mm to 600 mm, a crimpability of less than 5%, a mean degree of parallelism of less than 3°, and a number of wrap fiber groups in a range of from 0.5 to 20 per 1 cm in length of the yarn.
PRODUCING THE SAME
ABSTRACT OF THE DISCLOSURE
A fasciated yarn, consisting of wholly aromatic polyamide fibers, which is excellent in mechanical properties, especially in creep durability in a high temperature atmosphere and is suitably utilized for industrial usage. The yarn can be produced by a method comprising the steps of: stretch-breaking a filament tow of the wholly aromatic polyamide fibers to form a staple fiber bundle and imparting a false-twist to the staple fiber bundle by a vortex while retaining parallelism of the staple fibers composing the bundle, thereby obtaining the fasciated yarn. Structural characteristics of the yarn reside in a mean fiber length in the range of from 150 mm to 600 mm, a crimpability of less than 5%, a mean degree of parallelism of less than 3°, and a number of wrap fiber groups in a range of from 0.5 to 20 per 1 cm in length of the yarn.
Description
~s~
HE~T-DU~LE SPUN-LIKE FASCIATED YARN AND METHOD FOR
PRODUCING THE S~lE
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a spun-like fasci-ated yarn having good heat durability maintaining excel-lent mechanical strength and less creep deformation evenunder a high temperature condition exceeding 300C.
Description of the Prior ~rt It is well-known that wholly aromatic polyamide fibers such as poly-para-phenyleneterephthalamide or poly-meta-phenyleneisophthalamide which is on the market under the trade name "Kevlar ~ " from Du Pont de Nemours and Co. of USA or "Cornex ~ " from Teijin Limited of Japan, has superior mechanical strength and high modulus as well as good heat durability and anti-erosive proper-ties. Due to the above-mentioned advantages, they are widely utilized in the industrial field.
These fibers are used not only in filament form but also preferably in the form of spun yarn. For example, a bag filter is one of the suitable usages of the wholly ~0 aromatic polyamide fibers because the bag filter has to often be e~posed to a high temperature and erosive atmos-phere. In this case, a fabric woven from the spun yarn of such a fiber is expected to be more advantageous than a filament yarn fabric because of a better filtration ~5 ability caused by a relatively looser structure and a larger thickness of the spun yarn than of the filament yarn. However, according to a conventional spinning process, a resultant spun yarn cannot satisfactorily be applied to the aforesaid object due to the reasons explained below.
Since polymers of the above-mentioned heat durable fibers do not show a clear malting point but have a wide range decomposition polnt close to the~former, it is very ,~, ;
di~ficult to adopt a melt spinning system to prepare a fiber. Accordingly, the fiber can be formed only by the dry spinning or wet spinning of a solution in which the polymer is dissolved by a suitable solvent. Under such conditions, it is more advantageous to have a thicker tow for staple fibers than to have a plurality of thinner filament yarns. Since the tow for staple fibers has a very large thickness of, for example, from several dozen thousand denier to several hundred thousand denier, a higher draw ratio is hardly attainable. This insufficient drawing as well as a residual solvent in the fiber unre-moved during the spinning process result in an undesirable lower tensile strength and a lower Young's modulus of the resultant fiber than expected from a structure of a recurring unit of the polymer.
Further, to have a spun yarn, the tows thus obtained are cut into staple fibers after being crimped and~
thereafter, are subjected to a conventional complicated spinning process comprising scutching, carding, drawing, doubling, twisting, etc. As a result, the fibers in the spun yarn are considerably disoriented and deformed.
This causes, along with the crimps thereof, a greater elongation and lower strength of the yarn. Especially, since the wholly aromatic polyamide fiber lacks a spinna-bilty due to its hardness and rigidity, the abovesaidtendency is accelerated. Accordingly, the spun yarn has an undesirable creep deformation, especially in a high temperature atmosphere, compared to a filament yarn.
This is the reason why the conventional spun yarn of the wholly aromatic polyamide fibers is unsatisfactory in the above-mentioned object.
SUMMARY OF THE INVENTION
The present inventors have studied a long time to obtain a spun yarn having none of the drawbacks mentioned above, and succeeded in accomplishing the present inven-tion which provides an excellent spun yarn having a higher mechanical strength and a desirable anti-creep ~5~
property under a high temperature condition relative to those of a filament yarn. Before, it was believed that filament yarn was superior to spun yarn regarding the above~mentioned items due to ~he continuity thereof.
However, the yarn according to the present invention contradicts this belief.
It is an object of the present invention to provide a spun yarn having a good heat durability as well as a higher mechanical strength and anti-creep property.
It is another object of the present invention to provide a novel method for producing the same.
The object of the present invention is attainable by a fasciated yarn consisting of staple fibers of a wholly aromatic polyamide polymer prepared by the stretch--breaking of a tow; comprising a core portion and a plurality of wrap fiber groups wrapped around the core portion, the yarn being characterized in that the staple fiber has a mean fiber length within a range of from 150 mm to 600 mm, a crimpability of less than 5~, and a mean degree of parallelism (~) of less than 3, and that the number of the wrap fiber groups is within the range of from 0.5 to 20 per 1 cm in length of said yarn, and a method for producing a fasciated yarn consisting of staple fibers of a wholly aromatic polyamide polymer comprising the following steps of: stretch-breaking a tot~ o filaments into a bundle of staple fibers taking care not to disturb the parallelism thereof, each filament of said tow having a crimpability of less than 5~; and ~ubjecting said bundle of staple fibers, omitting the crimping process, to a fasciate spinning operation to form said fasciated yarn.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is now more fully described referring to the accompanying drawings, in which Figure 1 shows an enlarged side view of a fasciated yarn according to the present invention;
Fig. 2 is a diagrammatic elevational view of an - ~ -embodiment of an apparatus for carrying out the method according to the present invention;
Fig. 3 shows an enlarged oblique view of another embodiment of the apparatus for carrying out a method according to the present invention;
Fig. 4 is a partially sectional oblique view of a V-belt structure utilizing yarn according to the present invention;
Fig. 5 is a partially broken side view of a hose structure utilizing a yarn according to the present invention; and Fig. 6 is a graph of stress-strain curves of the present invented yarn and a conventional spun yarn of the same polymer fiber.
DESCRIPTION OF THE PREFERRED E~ODIMENTS
yarn according to the present invention is a ~asciated yarn of the same type as those disclosed in U~P No. 3,079,746 by F. C. Field, Jr. and No. 4,265,082 by Y. Sasaki et al. That is, the yarn comprises a core ~0 portion 1 having substantially no twist consisting of staple fibers and a plurality of wrap fiber groups 2 wrapped around the core portion.
The staple fibers composing the core portion 1 have to be substantially, parallel to an axis of the yarn.
HE~T-DU~LE SPUN-LIKE FASCIATED YARN AND METHOD FOR
PRODUCING THE S~lE
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a spun-like fasci-ated yarn having good heat durability maintaining excel-lent mechanical strength and less creep deformation evenunder a high temperature condition exceeding 300C.
Description of the Prior ~rt It is well-known that wholly aromatic polyamide fibers such as poly-para-phenyleneterephthalamide or poly-meta-phenyleneisophthalamide which is on the market under the trade name "Kevlar ~ " from Du Pont de Nemours and Co. of USA or "Cornex ~ " from Teijin Limited of Japan, has superior mechanical strength and high modulus as well as good heat durability and anti-erosive proper-ties. Due to the above-mentioned advantages, they are widely utilized in the industrial field.
These fibers are used not only in filament form but also preferably in the form of spun yarn. For example, a bag filter is one of the suitable usages of the wholly ~0 aromatic polyamide fibers because the bag filter has to often be e~posed to a high temperature and erosive atmos-phere. In this case, a fabric woven from the spun yarn of such a fiber is expected to be more advantageous than a filament yarn fabric because of a better filtration ~5 ability caused by a relatively looser structure and a larger thickness of the spun yarn than of the filament yarn. However, according to a conventional spinning process, a resultant spun yarn cannot satisfactorily be applied to the aforesaid object due to the reasons explained below.
Since polymers of the above-mentioned heat durable fibers do not show a clear malting point but have a wide range decomposition polnt close to the~former, it is very ,~, ;
di~ficult to adopt a melt spinning system to prepare a fiber. Accordingly, the fiber can be formed only by the dry spinning or wet spinning of a solution in which the polymer is dissolved by a suitable solvent. Under such conditions, it is more advantageous to have a thicker tow for staple fibers than to have a plurality of thinner filament yarns. Since the tow for staple fibers has a very large thickness of, for example, from several dozen thousand denier to several hundred thousand denier, a higher draw ratio is hardly attainable. This insufficient drawing as well as a residual solvent in the fiber unre-moved during the spinning process result in an undesirable lower tensile strength and a lower Young's modulus of the resultant fiber than expected from a structure of a recurring unit of the polymer.
Further, to have a spun yarn, the tows thus obtained are cut into staple fibers after being crimped and~
thereafter, are subjected to a conventional complicated spinning process comprising scutching, carding, drawing, doubling, twisting, etc. As a result, the fibers in the spun yarn are considerably disoriented and deformed.
This causes, along with the crimps thereof, a greater elongation and lower strength of the yarn. Especially, since the wholly aromatic polyamide fiber lacks a spinna-bilty due to its hardness and rigidity, the abovesaidtendency is accelerated. Accordingly, the spun yarn has an undesirable creep deformation, especially in a high temperature atmosphere, compared to a filament yarn.
This is the reason why the conventional spun yarn of the wholly aromatic polyamide fibers is unsatisfactory in the above-mentioned object.
SUMMARY OF THE INVENTION
The present inventors have studied a long time to obtain a spun yarn having none of the drawbacks mentioned above, and succeeded in accomplishing the present inven-tion which provides an excellent spun yarn having a higher mechanical strength and a desirable anti-creep ~5~
property under a high temperature condition relative to those of a filament yarn. Before, it was believed that filament yarn was superior to spun yarn regarding the above~mentioned items due to ~he continuity thereof.
However, the yarn according to the present invention contradicts this belief.
It is an object of the present invention to provide a spun yarn having a good heat durability as well as a higher mechanical strength and anti-creep property.
It is another object of the present invention to provide a novel method for producing the same.
The object of the present invention is attainable by a fasciated yarn consisting of staple fibers of a wholly aromatic polyamide polymer prepared by the stretch--breaking of a tow; comprising a core portion and a plurality of wrap fiber groups wrapped around the core portion, the yarn being characterized in that the staple fiber has a mean fiber length within a range of from 150 mm to 600 mm, a crimpability of less than 5~, and a mean degree of parallelism (~) of less than 3, and that the number of the wrap fiber groups is within the range of from 0.5 to 20 per 1 cm in length of said yarn, and a method for producing a fasciated yarn consisting of staple fibers of a wholly aromatic polyamide polymer comprising the following steps of: stretch-breaking a tot~ o filaments into a bundle of staple fibers taking care not to disturb the parallelism thereof, each filament of said tow having a crimpability of less than 5~; and ~ubjecting said bundle of staple fibers, omitting the crimping process, to a fasciate spinning operation to form said fasciated yarn.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is now more fully described referring to the accompanying drawings, in which Figure 1 shows an enlarged side view of a fasciated yarn according to the present invention;
Fig. 2 is a diagrammatic elevational view of an - ~ -embodiment of an apparatus for carrying out the method according to the present invention;
Fig. 3 shows an enlarged oblique view of another embodiment of the apparatus for carrying out a method according to the present invention;
Fig. 4 is a partially sectional oblique view of a V-belt structure utilizing yarn according to the present invention;
Fig. 5 is a partially broken side view of a hose structure utilizing a yarn according to the present invention; and Fig. 6 is a graph of stress-strain curves of the present invented yarn and a conventional spun yarn of the same polymer fiber.
DESCRIPTION OF THE PREFERRED E~ODIMENTS
yarn according to the present invention is a ~asciated yarn of the same type as those disclosed in U~P No. 3,079,746 by F. C. Field, Jr. and No. 4,265,082 by Y. Sasaki et al. That is, the yarn comprises a core ~0 portion 1 having substantially no twist consisting of staple fibers and a plurality of wrap fiber groups 2 wrapped around the core portion.
The staple fibers composing the core portion 1 have to be substantially, parallel to an axis of the yarn.
2~ Distortion of the core portion fibers is represented as a mean degree of parallelism 8 and has to be less than 3 thereof according to the invention. That is, the mean degree of parallelism 8 is an inclination of the staple fiber bundle composing the core portion relative to the axis of the yarn, a measurement being carried out accord-ing to the following steps:
1) preparing a length of 130 cm from the yarn to be measured as a test piece and marking thereon 12 marks at a distance of 10 cm;
2) selecting 10 measuring points on the marks by omitting the two disposed at opposite sides, and, at the points, measuring an inclination angle 3 of the core portion bundle relative to the central axis of the yarn under a field of vision of a microscope; and
1) preparing a length of 130 cm from the yarn to be measured as a test piece and marking thereon 12 marks at a distance of 10 cm;
2) selecting 10 measuring points on the marks by omitting the two disposed at opposite sides, and, at the points, measuring an inclination angle 3 of the core portion bundle relative to the central axis of the yarn under a field of vision of a microscope; and
3) repeating the measurement regarding lO
test pieces and calculating a ~ as a mean value of the obtained data by the following equation (l), The ~ exceeding 3 is not desirable, because the yarn shows an excess elongation corresponding to stress.
Further, the staple fiber composing the core portion has preferably no crimps, if any, a crimpability thereof being at most 5%. In this connection, the crimpability means a value measured according to JIS 1074-65, in which a single fiber of a length of 30 cm to be tested is loaded by a weight of 50 mg/d for 30 seconds and, thereafter, its length Q0 is measured, and the weight is replaced to a lighter one of 2 mg/d and, two minutes later, the length Ql of the fiber is measured, the crimpability CR
being calculated by the following equation (2), Q ~ Ql CR (~) = Q x lO0 ... (2) The average value for 10 test pieces is representa-tive of CR.
It is not preferable that the staple fibers in the core portion have the CR exceeding 5%, because, in such a case, the yarn becomes bulky causing a lower tensile strength and a greater elongation, especially under a high temperature condition.
A mean fiber length L of the staple fiber is neces-sarily within the range of from 150 mm to 600 mm. If thefiber length L is less than 150 mm, the tensile strength does not reach 3 g/d and, while, if the fiber length L is more than 600 mm, the yarn structure is similar to that of a filament yarn which lacks the bulkiness common in spun yarn. Both of them are not unsuitable for the object of the present invention.
The staple fiber composing the wrap fiber group 2 ~5~
ori~inates from ,he same source as the core portion fiber. One end of the wrap fiber is embedded in the core portion 1, and the other end thereof is free, which wraps around the core portion 1 and binds it to retain a yarn structure. The wrap fiber group fibers should have substantially the identical characteristics of the core portion fibers.
A number of wrap fiber groups N must be within the range of from 0.5 to 20 per 1 cm in length of the yarn in the mean value. If the number N is less than 0.5, the ~asciate action to the core portion is too weak to have a compact structure thereof, whereby yarn breakage may occur during a post operation such as weaving or knitting. On the other hand, wrap fiber groups of more than 20 per 1 cm in length naturally cause the decrease of the core portion fibers as well as the mean degree of parallelism ~
exceeding 3, both of which result-in undesirable low mechanical properties of the yarn.
The staple fibers composing the fasciated yarn 2~ according to the present invention consist of wholly aromatic polyamide polymer fibers. The wholly aromatic polyamide polymers herein-described include not only in a narrow sense such as the aforesaid poly-para-phenylene-teraphthalamide or poly-meta-phenyleneisophthalamide but also aromatic polyether amides having linkages defined below, in a wide sense.
That is, the term "aromatic polyether amide fiber"
used herein means a fiber composed of polymers which consist of the recurring units of the following formulas ~1) to (4):
- N - Arl - N - ... (1), Rl R2 - C - Ar2 ~ C - ,,, (2), O O
35 - IN - Ar3 - C - ... (3), and ., .
~2~
- I - Ar4 - Y - Ar3 - N - ... (4) wherein Arl , Ar2 ~ and Ar3 , which may be the same as or different from each other, stand for the aromatic carbo-cyclic rests, the bonding chains of which all extendcoaxially or parallel to the axis, or the aromatic hetero-cyclic rests, which are to be joined to adjacent atoms or grams by the ring atoms of the rests having the greatest distance, or combinations thereof, Ar4 and Ar5 , ~hich may be the same as or different from each other, stand for para- and meta-phenylene rests, Rl to R5 , which may be the same as or different from each other, stand for hydrogen atoms or alkyl rests containing not more than 5 carbon atms, and Y is selected from a group consisting of -O- , -S- , -S02- , -CH2- , -C- , -C-and -N- , wherain R6 is the same as Rl to R5 having the meaning defined above, said recurring units (1) to (4) having substantially the molar equation of (1) + (4~ = (2) and, when it is assumed that (1) + (2) + (3) + (4) = 100 mol%, ~3) = 0 to 90 mol~ and (4) = 50 to 5 mol~, preferably 30 to 10 mol~
As the aromatic carbocyclic rests with bonding chains extending coaxially, there may be mentioned, for example, 1,4-phenylene and 1,4-naphthylene rests. On the other hand, as the aromatic carboxylic rests with bonding chains extending parallel to the axis, there may be mentined, for example, 1,5-napthylene and 2,6-naphthylene.
The aromatic rests may be joined to each other by the rests selected from a group consisting of - N = N -, 3S - N = CH -, - CH = CH -, and - C -- C -. Th~ so joined aromatic rests include, for example, ~l2~
N = N ~ , ~ C C
~ CH = CH ~ and ~ N = CH ~
As the alkyl rests containing net more than 5 carbon atoms, there may be mentioned a methyl, an ethyl, a propyl, a butyl, a pentyl rest, and the like. Of these rests, methyl is preferable.
In the aromatic carbocyclic and heterocyclic rests, the hydrogen atoms bonded to the carbon atoms may be substituted. As such substituents, there may be mentioned halogen atoms (e.g., chlorine, bromine, and fluorine atoms), lower alkyl rests (e.g., methyl, ethyl, iso--propyl, and n-propyl rests), lower alkoxy rests (e.g., methoxy and ethoxy rests), a cyano rest, an acetyl rest, 1~ and a nitro rest. The chlorine atom and the methyl rest are preferable.
Fibers spinning from these polymers are well-known to have surprisingly excellent properties even in a high temperature atmosphere exceeding 300C.
It is not impossible, however, to attain the objects of the present invention by a spun yarn produced by means of the conventional spinning process in which the fibers are rearranged to a sliver form after being crimped and cut to staple fibers, because the abovesaid excellent properties of the fiber itself cannot be Eully utilized in such spun yarn.
In this connection, a novel method for producing the yarn according to the present invention is explained hereunder.
A fiber bundle used for the present inventive method is prepared by the so-called "stretch-breaking" of a filament tow. The fiber bundle thus prepared has to be fasciated while keeping a parallel orientation thereof.
Contrary to this, if using the conventional spinning process`in which the staple fibers prepared by cutting the ~ilament tow by a cutter are randomly mixed and then are rearranged to form a sliver, the orientation of the 5~
staple fiber in the resultant yarn cannot be completely parallelized and, in addition tc this, the crimp of the staple fiber, which is necessary to enhance the spinna-bility thereof, causes an undesirable creep elongation of the yarn relative to a filament yarn. Thus, according to the present invention, it is one of characteristics of the method to prepare the fiber bundle by taking care not to disturb the parallel orientation of the fiber origi-nally e~isting in the tow and not to deform the fiber by 10 crimping.
The stretch-breaking is also effective for the micro--structure of the fiber. That is, since each filament is drawn to the utmost extent by the stretching force to break a filament, the degree of molecular orientation in the micro-structure of the fiber can be greatly improved, thereby the staple fiber thus obtained has superior mechanical properties to those of the original filament.
Prior to the stretch-breaking of the tow, it is necessary to impart a suitable amount of oil and/or water to the tow to be processed due to a rigidity of the aromatic polyamide fiber. The stretch-breaking is carried out between a pair of feed rollers 5 and a pair of stretch rollers 6 rotating at a higher rate than that o the former as shown in Fig. 2, which illustrates an embodiment of the apparatus utilized for practicing the m~thod according to the invention. If the amount of the oil and/or water is too small, the tow may ~ecome charged with electricity which causes disturbance of the fiber parallelism or wrapping of the fibers around a metallic surface of the stretch rollers due to repulsion of the composing filaments. Contrary to this, if the amount of the oil and/or water is too large, slippage between the stretch rollers and the tow may occur, which makes it impossible to stretch-break the tow or, in an extreme condition, damages the apparatus due to frictional heat.
A suitable amount should be within a range af from 0.05 to 0.30~ for the oil and of less than 7% for the water - 10 ~
relative to the weight of the tow. More specifically, for the water, the more preferable range is di~ferent to respective wholly aromatic polyamide fibers due to their intrinsic water absorptions; that is, less than 6% for poly-para-phenylene terephthalamide, and less than 3% for aromatic polyether amide.
The mean fiber length of the staple fi~er stretch--broken from the tow depends on a distance between the eed rollers 5 and the stretch rollers 6 as well as a draw ratio therebetween.
The fiber bundle 4' thus stretch-broken is collec-tively guided to the stretch rollers 6 by a trumpet shaped chute 7 provided upstream of the former, and is thereby drated to a predetermined thickness sliver.
After being delivered from the s~retch roller 6, the fiber bundle 4' is introduced into an aspirator 8 provided downstream of the stretch roller 6 along with a suction flow. Downstream of the aspirator 8 is arranged an air nozzle 9 within which the fiber bundle 4', introduced therein in a ribbon form, is false-twisted by a vortex, so that edge portionfibers thereof entangle around a core portion thereof to form a resultant fasciated yarn. The structure of the air nozzle 9 is disclosed, for example, in the above-mentioned USP No. 3,079,746.
In the above-described false-twist operation in the air nozzle 9, care must be taken not to have any slack in the tension of the fiber bundle 4'~ In order to keep a suitable tension, a feed ratio of the stretch rollers 6 relative to draw-off rollers 10 provided downstream of the former has to be less than +4% preferably less than +1~ including a 0% or minus feed ratio. In case the feed ratio exceeding +4%, the core portion 1 of the resultant yarn is partially twisted in an S or Z direction which causes the mean degree of parallelism to be more than 3 and the number of the wrap fiber groups to be more than ~0 per 1 cm in length, both of which are not desirable as described before.
f~
The resultant fasciated yarn is continuously wound on a cheese 11.
The yarn thus obtained has, as it is, excellent properties suitable for attaining the objects of the present invention. However, the properties can be improved more by heat treatment carried out after the yarn forming.
This heat treatment may be exercised continuously subsequent to the false-twist operation, as illustrated in Fig. 3, by a heat roller 12, to a surface of which the yarn has made contact several times, or separately to the spinning process, may be carried out by an autoclave in which the cheese 11 of the yarn is steamed. The tempera-ture of the heat treatment is preferably more than 200C
and, thereby, the residual shrinkage and creep deformation of the yarn, especially in a high temperature atmosphere, can be improved to be suitable for usage under such conditions.
Tne present invention will be more apparent by the following examples showing the effects of the present invention.
Example 1 A filament tow of 4400 d/3000 f consisting of poly-para-phenyleneterephthalamide fibers was processed by the apparatus shown in Fig. 2. The tow had an oil content and a water content of 0.25% and ~.0~, respec-tively, by weight, and a fiber composing the tow had no crimps at all.
The distance and the draw ratio between the feed rollers 2 and the stretch rollers 6 were adjusted to 750 mm and 25 times, respectively. The tow was stretch~
-broken to a staple fiber bundle having a mean fiber length L of 312 mm and, finally, was formed into a fasciated yarn of 30 S (cotton count) according to the present invention. Air pressures utilized for the aspirator 8 and the air nozzle 9 were 3 kg/cm and 5 kg/cm2, respectively.
Example 2 A ~ilament tow of 3000 d/2000 f consisting of aromatic polyetheramide fibers having no crimps, con-sisting of 25 mol% of para-phenylenediamine, 25 mol% of 3.4'-diaminodiphenylether, and 50 mol% o~ terephthalic acid was processed by the apparatus shown in Fig. 2.
The tow had an oil and water content of 0.1% and 1.6%, respectively, by weight.
The distance and the draw ratio between the feed rollers 2 and the stretch rollers 6 were adjusted to 750 mm and 20 times, respectively. The tow was stretch--broken to a staple fiber bundle having a mean fiber length L of 290 mm and, finally, was formed into a ~a~ciated yarn of 35 S (cotton count) according to the present invention. Air pressures utilized for the aspirator 8 and the air nozzle 9 were the same as Example l.
Example 3 A filament tow of 7000 d/3500 f consisting of poly-meta-phenyleneisophthalamide fibers having no crimps was processed as the same manner described in Examples l and 2. The distance and the draw ratio between the feed rollars 2 and the stretch rollers 6 were adjusted to 600 mm and 26 times, respectively. The tow was stretch--broken to a staple fiber bundle having a mean fiber length L o~ 230 mm and, finally, was formed in-to a ~asciated yarn of 20 S (cotton count) according to the present invention. Air pressures utilized for the aspirator 8 and the air nozzle 9 were 4 kg/cm2, respec-tively.
Comparative Examples l and 2 The tow processings were carried out on the sametow utilized in Example 3 under the same conditions as Examples l and 2, except that the roller distances were 35 adjusted to 280 mm and 1800 mm, respectively, thereby obtaining two comparative yarns having mean fiber lengths L of 103 mm and 710 mm, respectively.
58~
Comparative Example 3 The same filament tow as utilized in Example 3 was crimped, prior to the stretch-breaking operation, to have a crimpability CR of 10% by a stuffer box system without heating. The tow was processed under the same conditions as Example 3, thereby obtaining a comparative yarn of ~xcess crimpability.
Comparative Example 4 The same filament tow as utilized in Example 3 was processed under the same conditions as Example 3 except that the feed ratio between the two pairs of rollers 6 and 10 was adjusted ~o +7%, thereby obtaining a compara-tive yarn of the mean degree of parallelism ~ of 4.
Comparative Examples 5 and 6 Tow processings were carried out with the same tow as utilized in Example 3 under the same conditions thereof, except ~hat the feed ratios between the two pairs of rollers 6 and 10, and the air pressure of the aspirator 8 and the air nozzle 9 were adjusted to the following sets of values: (1) feed ratio -2%, air pressure 2 kg/cm2 respectively, and (2) feed ratio +8%, air pressure 6 kg/cm2 respectively, thereby obtaining two comparative yarns having the number of wrap fiber groups N of 0.42/cm and 23.0/cm, respectively.
Characteristics of the yarns thus obtained by E~amples 1 through 3 and the Comparative Examples 1 through 6 are shown in Table 1, from which the excel-lence, in the mechanical properties, of the yarns according to the present invention is apparent compared to the yarns of the comparative examples.
test pieces and calculating a ~ as a mean value of the obtained data by the following equation (l), The ~ exceeding 3 is not desirable, because the yarn shows an excess elongation corresponding to stress.
Further, the staple fiber composing the core portion has preferably no crimps, if any, a crimpability thereof being at most 5%. In this connection, the crimpability means a value measured according to JIS 1074-65, in which a single fiber of a length of 30 cm to be tested is loaded by a weight of 50 mg/d for 30 seconds and, thereafter, its length Q0 is measured, and the weight is replaced to a lighter one of 2 mg/d and, two minutes later, the length Ql of the fiber is measured, the crimpability CR
being calculated by the following equation (2), Q ~ Ql CR (~) = Q x lO0 ... (2) The average value for 10 test pieces is representa-tive of CR.
It is not preferable that the staple fibers in the core portion have the CR exceeding 5%, because, in such a case, the yarn becomes bulky causing a lower tensile strength and a greater elongation, especially under a high temperature condition.
A mean fiber length L of the staple fiber is neces-sarily within the range of from 150 mm to 600 mm. If thefiber length L is less than 150 mm, the tensile strength does not reach 3 g/d and, while, if the fiber length L is more than 600 mm, the yarn structure is similar to that of a filament yarn which lacks the bulkiness common in spun yarn. Both of them are not unsuitable for the object of the present invention.
The staple fiber composing the wrap fiber group 2 ~5~
ori~inates from ,he same source as the core portion fiber. One end of the wrap fiber is embedded in the core portion 1, and the other end thereof is free, which wraps around the core portion 1 and binds it to retain a yarn structure. The wrap fiber group fibers should have substantially the identical characteristics of the core portion fibers.
A number of wrap fiber groups N must be within the range of from 0.5 to 20 per 1 cm in length of the yarn in the mean value. If the number N is less than 0.5, the ~asciate action to the core portion is too weak to have a compact structure thereof, whereby yarn breakage may occur during a post operation such as weaving or knitting. On the other hand, wrap fiber groups of more than 20 per 1 cm in length naturally cause the decrease of the core portion fibers as well as the mean degree of parallelism ~
exceeding 3, both of which result-in undesirable low mechanical properties of the yarn.
The staple fibers composing the fasciated yarn 2~ according to the present invention consist of wholly aromatic polyamide polymer fibers. The wholly aromatic polyamide polymers herein-described include not only in a narrow sense such as the aforesaid poly-para-phenylene-teraphthalamide or poly-meta-phenyleneisophthalamide but also aromatic polyether amides having linkages defined below, in a wide sense.
That is, the term "aromatic polyether amide fiber"
used herein means a fiber composed of polymers which consist of the recurring units of the following formulas ~1) to (4):
- N - Arl - N - ... (1), Rl R2 - C - Ar2 ~ C - ,,, (2), O O
35 - IN - Ar3 - C - ... (3), and ., .
~2~
- I - Ar4 - Y - Ar3 - N - ... (4) wherein Arl , Ar2 ~ and Ar3 , which may be the same as or different from each other, stand for the aromatic carbo-cyclic rests, the bonding chains of which all extendcoaxially or parallel to the axis, or the aromatic hetero-cyclic rests, which are to be joined to adjacent atoms or grams by the ring atoms of the rests having the greatest distance, or combinations thereof, Ar4 and Ar5 , ~hich may be the same as or different from each other, stand for para- and meta-phenylene rests, Rl to R5 , which may be the same as or different from each other, stand for hydrogen atoms or alkyl rests containing not more than 5 carbon atms, and Y is selected from a group consisting of -O- , -S- , -S02- , -CH2- , -C- , -C-and -N- , wherain R6 is the same as Rl to R5 having the meaning defined above, said recurring units (1) to (4) having substantially the molar equation of (1) + (4~ = (2) and, when it is assumed that (1) + (2) + (3) + (4) = 100 mol%, ~3) = 0 to 90 mol~ and (4) = 50 to 5 mol~, preferably 30 to 10 mol~
As the aromatic carbocyclic rests with bonding chains extending coaxially, there may be mentioned, for example, 1,4-phenylene and 1,4-naphthylene rests. On the other hand, as the aromatic carboxylic rests with bonding chains extending parallel to the axis, there may be mentined, for example, 1,5-napthylene and 2,6-naphthylene.
The aromatic rests may be joined to each other by the rests selected from a group consisting of - N = N -, 3S - N = CH -, - CH = CH -, and - C -- C -. Th~ so joined aromatic rests include, for example, ~l2~
N = N ~ , ~ C C
~ CH = CH ~ and ~ N = CH ~
As the alkyl rests containing net more than 5 carbon atoms, there may be mentioned a methyl, an ethyl, a propyl, a butyl, a pentyl rest, and the like. Of these rests, methyl is preferable.
In the aromatic carbocyclic and heterocyclic rests, the hydrogen atoms bonded to the carbon atoms may be substituted. As such substituents, there may be mentioned halogen atoms (e.g., chlorine, bromine, and fluorine atoms), lower alkyl rests (e.g., methyl, ethyl, iso--propyl, and n-propyl rests), lower alkoxy rests (e.g., methoxy and ethoxy rests), a cyano rest, an acetyl rest, 1~ and a nitro rest. The chlorine atom and the methyl rest are preferable.
Fibers spinning from these polymers are well-known to have surprisingly excellent properties even in a high temperature atmosphere exceeding 300C.
It is not impossible, however, to attain the objects of the present invention by a spun yarn produced by means of the conventional spinning process in which the fibers are rearranged to a sliver form after being crimped and cut to staple fibers, because the abovesaid excellent properties of the fiber itself cannot be Eully utilized in such spun yarn.
In this connection, a novel method for producing the yarn according to the present invention is explained hereunder.
A fiber bundle used for the present inventive method is prepared by the so-called "stretch-breaking" of a filament tow. The fiber bundle thus prepared has to be fasciated while keeping a parallel orientation thereof.
Contrary to this, if using the conventional spinning process`in which the staple fibers prepared by cutting the ~ilament tow by a cutter are randomly mixed and then are rearranged to form a sliver, the orientation of the 5~
staple fiber in the resultant yarn cannot be completely parallelized and, in addition tc this, the crimp of the staple fiber, which is necessary to enhance the spinna-bility thereof, causes an undesirable creep elongation of the yarn relative to a filament yarn. Thus, according to the present invention, it is one of characteristics of the method to prepare the fiber bundle by taking care not to disturb the parallel orientation of the fiber origi-nally e~isting in the tow and not to deform the fiber by 10 crimping.
The stretch-breaking is also effective for the micro--structure of the fiber. That is, since each filament is drawn to the utmost extent by the stretching force to break a filament, the degree of molecular orientation in the micro-structure of the fiber can be greatly improved, thereby the staple fiber thus obtained has superior mechanical properties to those of the original filament.
Prior to the stretch-breaking of the tow, it is necessary to impart a suitable amount of oil and/or water to the tow to be processed due to a rigidity of the aromatic polyamide fiber. The stretch-breaking is carried out between a pair of feed rollers 5 and a pair of stretch rollers 6 rotating at a higher rate than that o the former as shown in Fig. 2, which illustrates an embodiment of the apparatus utilized for practicing the m~thod according to the invention. If the amount of the oil and/or water is too small, the tow may ~ecome charged with electricity which causes disturbance of the fiber parallelism or wrapping of the fibers around a metallic surface of the stretch rollers due to repulsion of the composing filaments. Contrary to this, if the amount of the oil and/or water is too large, slippage between the stretch rollers and the tow may occur, which makes it impossible to stretch-break the tow or, in an extreme condition, damages the apparatus due to frictional heat.
A suitable amount should be within a range af from 0.05 to 0.30~ for the oil and of less than 7% for the water - 10 ~
relative to the weight of the tow. More specifically, for the water, the more preferable range is di~ferent to respective wholly aromatic polyamide fibers due to their intrinsic water absorptions; that is, less than 6% for poly-para-phenylene terephthalamide, and less than 3% for aromatic polyether amide.
The mean fiber length of the staple fi~er stretch--broken from the tow depends on a distance between the eed rollers 5 and the stretch rollers 6 as well as a draw ratio therebetween.
The fiber bundle 4' thus stretch-broken is collec-tively guided to the stretch rollers 6 by a trumpet shaped chute 7 provided upstream of the former, and is thereby drated to a predetermined thickness sliver.
After being delivered from the s~retch roller 6, the fiber bundle 4' is introduced into an aspirator 8 provided downstream of the stretch roller 6 along with a suction flow. Downstream of the aspirator 8 is arranged an air nozzle 9 within which the fiber bundle 4', introduced therein in a ribbon form, is false-twisted by a vortex, so that edge portionfibers thereof entangle around a core portion thereof to form a resultant fasciated yarn. The structure of the air nozzle 9 is disclosed, for example, in the above-mentioned USP No. 3,079,746.
In the above-described false-twist operation in the air nozzle 9, care must be taken not to have any slack in the tension of the fiber bundle 4'~ In order to keep a suitable tension, a feed ratio of the stretch rollers 6 relative to draw-off rollers 10 provided downstream of the former has to be less than +4% preferably less than +1~ including a 0% or minus feed ratio. In case the feed ratio exceeding +4%, the core portion 1 of the resultant yarn is partially twisted in an S or Z direction which causes the mean degree of parallelism to be more than 3 and the number of the wrap fiber groups to be more than ~0 per 1 cm in length, both of which are not desirable as described before.
f~
The resultant fasciated yarn is continuously wound on a cheese 11.
The yarn thus obtained has, as it is, excellent properties suitable for attaining the objects of the present invention. However, the properties can be improved more by heat treatment carried out after the yarn forming.
This heat treatment may be exercised continuously subsequent to the false-twist operation, as illustrated in Fig. 3, by a heat roller 12, to a surface of which the yarn has made contact several times, or separately to the spinning process, may be carried out by an autoclave in which the cheese 11 of the yarn is steamed. The tempera-ture of the heat treatment is preferably more than 200C
and, thereby, the residual shrinkage and creep deformation of the yarn, especially in a high temperature atmosphere, can be improved to be suitable for usage under such conditions.
Tne present invention will be more apparent by the following examples showing the effects of the present invention.
Example 1 A filament tow of 4400 d/3000 f consisting of poly-para-phenyleneterephthalamide fibers was processed by the apparatus shown in Fig. 2. The tow had an oil content and a water content of 0.25% and ~.0~, respec-tively, by weight, and a fiber composing the tow had no crimps at all.
The distance and the draw ratio between the feed rollers 2 and the stretch rollers 6 were adjusted to 750 mm and 25 times, respectively. The tow was stretch~
-broken to a staple fiber bundle having a mean fiber length L of 312 mm and, finally, was formed into a fasciated yarn of 30 S (cotton count) according to the present invention. Air pressures utilized for the aspirator 8 and the air nozzle 9 were 3 kg/cm and 5 kg/cm2, respectively.
Example 2 A ~ilament tow of 3000 d/2000 f consisting of aromatic polyetheramide fibers having no crimps, con-sisting of 25 mol% of para-phenylenediamine, 25 mol% of 3.4'-diaminodiphenylether, and 50 mol% o~ terephthalic acid was processed by the apparatus shown in Fig. 2.
The tow had an oil and water content of 0.1% and 1.6%, respectively, by weight.
The distance and the draw ratio between the feed rollers 2 and the stretch rollers 6 were adjusted to 750 mm and 20 times, respectively. The tow was stretch--broken to a staple fiber bundle having a mean fiber length L of 290 mm and, finally, was formed into a ~a~ciated yarn of 35 S (cotton count) according to the present invention. Air pressures utilized for the aspirator 8 and the air nozzle 9 were the same as Example l.
Example 3 A filament tow of 7000 d/3500 f consisting of poly-meta-phenyleneisophthalamide fibers having no crimps was processed as the same manner described in Examples l and 2. The distance and the draw ratio between the feed rollars 2 and the stretch rollers 6 were adjusted to 600 mm and 26 times, respectively. The tow was stretch--broken to a staple fiber bundle having a mean fiber length L o~ 230 mm and, finally, was formed in-to a ~asciated yarn of 20 S (cotton count) according to the present invention. Air pressures utilized for the aspirator 8 and the air nozzle 9 were 4 kg/cm2, respec-tively.
Comparative Examples l and 2 The tow processings were carried out on the sametow utilized in Example 3 under the same conditions as Examples l and 2, except that the roller distances were 35 adjusted to 280 mm and 1800 mm, respectively, thereby obtaining two comparative yarns having mean fiber lengths L of 103 mm and 710 mm, respectively.
58~
Comparative Example 3 The same filament tow as utilized in Example 3 was crimped, prior to the stretch-breaking operation, to have a crimpability CR of 10% by a stuffer box system without heating. The tow was processed under the same conditions as Example 3, thereby obtaining a comparative yarn of ~xcess crimpability.
Comparative Example 4 The same filament tow as utilized in Example 3 was processed under the same conditions as Example 3 except that the feed ratio between the two pairs of rollers 6 and 10 was adjusted ~o +7%, thereby obtaining a compara-tive yarn of the mean degree of parallelism ~ of 4.
Comparative Examples 5 and 6 Tow processings were carried out with the same tow as utilized in Example 3 under the same conditions thereof, except ~hat the feed ratios between the two pairs of rollers 6 and 10, and the air pressure of the aspirator 8 and the air nozzle 9 were adjusted to the following sets of values: (1) feed ratio -2%, air pressure 2 kg/cm2 respectively, and (2) feed ratio +8%, air pressure 6 kg/cm2 respectively, thereby obtaining two comparative yarns having the number of wrap fiber groups N of 0.42/cm and 23.0/cm, respectively.
Characteristics of the yarns thus obtained by E~amples 1 through 3 and the Comparative Examples 1 through 6 are shown in Table 1, from which the excel-lence, in the mechanical properties, of the yarns according to the present invention is apparent compared to the yarns of the comparative examples.
4~
~ C ~ ~Cx) ~V ''~
~ N ~r O Q t`l ~1 ~ ~ ~I c; o ~'~o ~ (` O O ~I
~1 o _i c; ci , 1 ~r ~
.,~ ~t~ ~ ~ O Q r~ cr~ ~ 1 C~ ~ CO
~ C ~ ~ 3 Cl~ C t`i ~i ~ N C`i ~ ~i ~ .~ ,. `
~ C ~ ~Cx) ~V ''~
~ N ~r O Q t`l ~1 ~ ~ ~I c; o ~'~o ~ (` O O ~I
~1 o _i c; ci , 1 ~r ~
.,~ ~t~ ~ ~ O Q r~ cr~ ~ 1 C~ ~ CO
~ C ~ ~ 3 Cl~ C t`i ~i ~ N C`i ~ ~i ~ .~ ,. `
5 ~ _ ~ _~ o cr~ o Q
~ ~ ~P ~ w ~r ~ o ~7 Z; ~1 ,, o r~ O
~3 ~ O Q U~ ~i cn ~ o ~
.~ _I c~ ~ cr. co ~ o ,~ ~1 ~1 --¦ ,i N ~i ~ C; ~ ~r ~i U7 ~ ~ O O O O O ~ o; O c;
~ 1~ ~ ~N ~ ~ ~
u~ ~ = = = =
fi~
l~ ~ ~
5~
Note:
(l) poly~para-phenyleneterephthalamide (2) aromatic polyether amide (3) poly-meta-phenyleneisophthalamide (~) The mechanical properties were measured on a twisted yarn of 300 t/m.
(5) The creep durability was measured by the method in which a test piece is loaded by a weight of 0.33 g/d in the atmosphere at a temperature of 250C for 2 hours and thereafter an elongation is calculated from the lengths of the test piece before and after loading.
~ ~ ~P ~ w ~r ~ o ~7 Z; ~1 ,, o r~ O
~3 ~ O Q U~ ~i cn ~ o ~
.~ _I c~ ~ cr. co ~ o ,~ ~1 ~1 --¦ ,i N ~i ~ C; ~ ~r ~i U7 ~ ~ O O O O O ~ o; O c;
~ 1~ ~ ~N ~ ~ ~
u~ ~ = = = =
fi~
l~ ~ ~
5~
Note:
(l) poly~para-phenyleneterephthalamide (2) aromatic polyether amide (3) poly-meta-phenyleneisophthalamide (~) The mechanical properties were measured on a twisted yarn of 300 t/m.
(5) The creep durability was measured by the method in which a test piece is loaded by a weight of 0.33 g/d in the atmosphere at a temperature of 250C for 2 hours and thereafter an elongation is calculated from the lengths of the test piece before and after loading.
(6) The heat shrinkage was calculated from the length of the test piece freely shrunk in a dry heat environment of 210C.
l~ Example 4 A filament tow of 7000 d/6000 f consisting of poly-meta-phenyleneisophthale amide fibers having no crimps ~as processed by the apparatus shown in Fig. 2.
The distance and the draw ratio between the feed rollers 2 and the stretch rollers 6 were adjusted to 600 mm and 26 times, respectively. The tow was stretch--broken to a staple fiber bundle having a mean fiber langth L of 230 mm and, inally, was formed into a fasciated yarn A of 20 S (cotton count) by adjusting the 2~ air pressures of the aspirator and the air nozzle to 4 kg/cm2 and 5 kg/cm2, respectively.
On the other hand, the same tow as described in Example 4, was cut to form staple fibers of 2 inch lengths after crimps were imparted by a stufer box 30 system, and the staple fibers were spun to become a spun yarn B as a comparative example by means of a conventional cotton spinning system.
Measurement was carried out on the two yarns A and B
regarding a tensile strength, results of which are shown 35 on the graph in Fig. 6.
As is apparent from the graph, the yarn A according to the present invention shows a dif~erent stress-strain curve ~rom that of the comparative yarn B.
Further, the creep durabilities of both the yarn A
and B were 0.5% and 5.0~, respectively.
Next, how the present invented yarn is utilized in the industrial material field, is explained.
The yarn according to the present invention can be utilized for a bag filter, because of its excellent mechanical strength and creep durability in a high temperature condition. Further, the yarn is suitable for a reinforcing member embedded in a mold material such as rubber because the yarn is rich in fluffs and in inter--fiber porosity which enhance the anchoring effect in the mold material~ The yarn also can be preferably utilized for sewing thread due to its heat radiation ability which serves to suppress the temperature elevation of a sewing needle even at a high sewing speed.
The above-mentioned effects will be more apparent by the following examples.
Example 5 A fasciated yarn of 20 S (cotton count)having a mean fiber length of 230 mm was prepared from a ilament tow of 7000 d/1000 f consisting of poly-meta-phenyleneiso-phthalamide fibers by utilizing the apparatus shown in Fig. ~.
A bag filter C according to the present invention was manufactured from a satin made of the abovesaid yarn.
Densities of the warp and weft were 73 ends/in and 57 picks/in, respectively.
On the other hand, another bag filter D was manu-factured from the same kind of fabric made of the yarn B
as described in Example 4 as a comparative example.
The two bag filters C and D were tested on air permeability and dimensional stability, results of which are tabulated in Table 2.
~ . .
.
Table 2 Air Permeability( ) Dimensional( ) (cc/cm2/sec)_ Stability (%) Note:
~l) The air permeability was measured according to JIS-L 1096-6-27-1-A.
(2) The dimensional stability was calculated from an elongation of the bag filter when being exposed in the atmosphere at a temperature of 200C under a load of 20 ~g~10 cm in width for 7 days.
Example 6 A fasciated yarn of 3.6 S (cotton count) was pro-duced, according to the present invention, from a filament tow of 150,000 d consisting of the same aromatic polyether amide fiber as utilized in Example 2 by means of the apparatus shown in Fig. 2, thereby being knit in a tubular braid. The braid was layered in a hose structure as an inner reinforcement 52 along with an inner rubber layer 51, a polyester filament fabric 53, and an outer ~5 rubber layer 54.
On the other hand, a filament yarn of 1500 d/1000 f consisting of the same polymer fiber as above was knit to form the same tubular braid and, thereafter, was incorpo-rated into a comparàtive hose structure instead of the abovesaid inner reinforcement 52.
Comparison of the two hoses in shown in Table 3.
5~
Table 3 Measured Item Processing Example 6 Comparative Oil Durability Untreated 1803 1712 ,(100)(100) (kglcm~)150C x 100 hr 1803 1712 (~) (100)(100) 150C x 200 hr 1785 1678 ~99) (98) 150C x 500 hr 1767 1644 (98) ~96) Wearability 83.5 68.2 ChemicalUntreated 100 100 Durability N2SO4 g9 96 NaOH 97 9~
Steam Untreated 100 100 Durability 150C x 500 hr 93.6 87,3 in steam The measurements of each item are as follows:
1. Oil Durability Three hoses to be tested were filled with brake oil and were left in the atmosphere at a temperature of 150C for 100, 200, and 500 hours, respectively. Each burst test was carried out on one of the hoses at each time period.
2. Wearability A hose to be tested was subjected to repeated bending motions caused by a pulley, on which the hose was mounted. The pulley had a diameter 15 times of the hose width and was rotated reciprocally at a rate of 10 mtsec.
After 2000 revolutions under a tension of 5 kg/cm, the breaking strength of the hose was measured.
~2~5~
From this value and the strength of the untreateed one, the strength retaining ratio was calculated.
3. Chemical Durabiity ~o hoses to be tested were immersed into a solution of ~0% sulfuric acid at 90C and a solution of 10~ caustic soda at 95C, respectively, for 100 hours From the breaking strengths or the treated hoses and the untreated one, the strength retaining ratios to each chemical were calculated.
4. Steam Durability Throu~h a hose to be tested, super heated steam of 150C was introduced for 500 hours. From the breaking strengths of the treated hose and the untreated hose, the strength retaining ratios were calculated.
Example 7 The same fasciated yarn of 3.6 S (cotton count) as obtained in Example 6 was two-plied with an S twist of 10 t/10 cm to form a cord according to the present inven-tion. The cord was immersed into a first bath, which was followed by drying at 150C for 1 minute and baking at 240C for 1 minute. Then, the cord was ~mmersed into a second bath which was followed by drying at 150C for 1 minute and baking at 240C for 1 minute, thereby obtaining a cohesive cord for a timing belt. Formulas of the first and second baths are as follows:
First bath Denacol ~ FX-611 (NAGASE SANGYO K K.) (sorbitolpolyglycidile ether) 6 parts 3~ Neocol ~ SW-30 (DAIICHI KOGYO SEIYAKU K.K.) (dioctylsulfosuccinate-natrium salt) 4 parts Hylene ~ MP (Du Pont De Nemours & Ço.) (phenol blocked 4,4'-diphenyle-methanediisocyanate) 60 parts 35Nipol ~ 2518FS (Nippon Zeon K.K.J
(vinylpyridine-styrene-butadiene polymer) 125 parts . _ . . .
' ' ~9L5~
Water 805 parts Total 1000 parts Second bath Resorein 15 parts Formalin ~37 weight~)17 parts Caustic Soda Solution (10 weight%) 6 parts Nipol ~ 251FS (40 weight%)400 parts Water 562 parts Total 1000 parts On the other hand, utilizing a filament yarn of 1500 d/1000 f consisting of the same aromatic polyether amide fibers as the above-said invented yarn, another cord was prepared, as a comparative example, according to the same process as described above.
Comparisons between the two cords and ~etween the two timing belts for automobile engine utilizing the each ~ord are shown in Table 4.
Table 4 Comparative Characteristics Example 7 Example ~ORD Breaking Strength (kg) 96 78 Young's Modulus (kg/d) 650 590 Pull-Out Force (kg/cm) 27 16 Wet Heat Durability (%) 98 95 BELT Wearability 100 hr 98 95 (%) 200 hr 96 85 Measurements of each item are as follows:
1. Breaking Strength and Young's Modulus These items were tested by means of a Tensiron st~ess-strain tester provided by TOYO-BALDWIN K.K.
2. Pull-Out Force ` ~
~2~58~
A two-plied cohesive cord to be tested was e~bedded in a rubber layer of 1 cm width composing a timing belt, so that the cord was directed perpendicular to the longitudinal direction of the belt. Then tne belt was vulcanized under a temperature of 160C for 20 minutes. A force was measured, which is necessary to pull out the cord from the structure of the vulcanized belt, at a rate of 200 cm/min.
3. ~et Heat Durability A cord to be tested was treated in an autoclave filled with steam of 150C (6 kg~cm2) for 100 hours.
The str~ngth retaining ratios were calculated from the breaking strengths of the treated cord and the untreated one.
1~ 4. Wearability A cord to be tested was subjected to repeated elongations of 6~ and compressions of 18~, caused by a ~oodrich type disc tester, for 100 hours or 200 hours.
The strength retainin~ ratios were calculated from the ~0 breaking strengths of the treated cord and the untreated one.
Example 8 The same fasciated yarn of 3.6 S (cotton count) as obtained in Example 6 was two-plied with a primary twist of 109 t/m and, then, the resultant yarn was three-plied with a final twist of 227 t/m to form a cord. The cord was incorporated into a V-belt as shown in Fig. 4, in wh~.ch reference numerals 41 and 45 designate cotton fabrics, respectively; 42 and 44 chloroprene rubber layers, respectively; and 43 the cord consisting of the invented yarns.
On the other hand, utilizing a filament yarn of 1500 d/1000 f consisting of the same aromatic polyether amide fibers as the invented yarn, another cord was prepared according to the same process as described above and was incorporated into another V-belt as a comparative example.
~ ~ "
Comparisons between the two V belts are shown in Table 5.
Table 5 Comparative Measured Item Example 8 Example Breaking Strength~kg) 1435 1404 Breaking Elongation~) 1.0 1.5 Young's Modulus(g/d) 540 480 Wearability ~kg) 1390 1260 Creep Durability (%) 0 0 Wet Heat Dimensional Stability (~) 0 0 Untreated 100 100 Chemical Durability (Strength retainingH2SO4 99 96 ratio) (~) NaOH 97 ~4 Measurements of each item are as follows:
1. Breaking Strength, Breaking Elongation, and Young's Modulus ~S These items were tested by means of a Tensiron stress-strain tester provided by TOYO-BALDWIN K.K..
2. Wearability The V-belt to be tested was subjected to repeated bendings caused by a pulley, on which the V-belt was mountted. The pulley had a diameter 15 times of the V-belt width and was rotated at a rate of 10 m/sec. After 109 revolutions in the atmosphere having a temperature of 16C and an RH of 65~ under a tension of 5 kg/cm, the breaking st~ength of the V-belt was measured and the strength retaining ratio was calculated relative to the untreated one.
3. Creep Durability ~5 A creep tester provided by K.K. IW~OTO
S~IS~USHO was utilized.
4. Wet Heat Dimensional Stability The V-belt to be tested was subjected to repeated bendings under conditions of 40C temperature and 100~ RH by the same device as utilized for testing the wearability. After 109 revolutions under a tension of 1 kg/cm, the dimensions of the V-belt were measured and compared to the original ones.
5. ~hemical Durability Two V-belts to be tested were immersed into aqueous solutions of 20% sulfuric acid at 95C, and 10 caustic soda at 95C, respectively, for 100 hours.
From breaking strengths of the teated V-belts and that of the untreated one, the strength retaining ratios to each chemical were obtained.
E~ample 9 The same fasciated yarn of 3.6 S (cotton count) as obtained in Example 6 was chopped to a plurality o pieces 2a of 5 mm in length. The chopped pieces were mixed with a heat durable rubber composition described in Table 6 with a weight ratio of 2.0:100, and the mixed composition was extruded through a slit to form a mold A in a sheet form of 3 mm in thickness. The mold A was processed, according ~5 to the following steps, to have a test piece: preparing two sheets of the above-said rubber composition not containing the chopped pieces, having thicknesses of 5 mm and 2 mm, respectively; interposing a canvas woven from a polyester yarn between the prepared two sheets to form a layered sample of 30 mm in width; peeling the rubber sheet of 5 mm in thickness along a 100 mm length and complementing a separately prepared rubber sheet of 2 mm in thickness of the same composition and the mold A of 3 mm in thickness in a layered manner to have a sample;
and vulcanizing the sample under a pressure of 50 kg/cm2 to make a finished test piece.
The test piece was subjected to repeated bendings of ~58'~
60 H~ by means of a hot pulley of 125C surface tempera-ture and a 75 mm diameter under a tension of 55 kg, and the time required to cause a crack on a surface of the test piece was measured.
On the other hand, as a comparative example, a mold B was prepared by utilizing a filament yarn of 15dO d/1000 f consisting of the same aromatic polyether amide fibers as the yarn utilized in the mold A, and another test piece was obtained in accordance with the 1~ same manner as described above and subjected to the ~racking test.
The results of the tests are tabulated in Table 7 showing data for two test pieces for each of the molds A
and B, one of which was prepared along an orientation of the chopped pieces and the other perpendicular thereto.
In this connection, the chopped pieces in the rubber composition are easily oriented along a flowing direction by being passed through a conduit in a fluid state before extrusion.
Table 6 Component Parts by weight Copolymerized rubber of 70 Ethylene-Hexafluoropropylene Copolymerized Rubber of 20 Ethylene-Propylene Chlorinated Butylic Rubber 10 Carbon 25 Zinc Oxide 5 Stearic Acid 0.5 Antioxidant ) 3 Peroxide ) 2.5 Triallylisocyanurate 1.5 Note: 1) mercaptobenzimidazol 2) PETROXIMON ~ F-400 (NIPPON YUSHI K.K.) Table 7 _ _ Orlentation Test Piece Cracking (hr) Example 9 87 Comparative 74 Example Example 9 61 Comparative 43 Example Example 10 A filament tow of 3000 denier consisting of the same aromatic polyether amide fibers as utilized in Example 2 ~ " .
~2~5~ ~
was processed by the apparatus shown in Fig. 2 to form a fasciated yarn A of 53 S (cotton count) according to the present invention. The yarn A was two-plied with a primary twist of S 700 t/m and the resultant yarn was three-plied with a final twist of Z 450 t/m, thereby obtaininq a sewing thread.
On the other hand, three comparative sewing threads B, C, and D consisting of a polyester filament yarn, a spun yarn of poly-meta-phenyleneisophthalate staple fibers of 50 mm length, and a filament yarn of the same aromatic polyether amide fibers as the yarn A, respec-tively, were prepared.
Sewing tests were carried out on the four sewing threads, and the results thereof are shown in Table 8.
It is apparent from Table 8 that the thread A
according to the present invention shows a constant mechanical strength throughout the sewing operation, and further suggests a possibility to endure a higher sewing rate than the one consisting of the filament yarn.
;~5~ ~
Table 8 Test Piece Example 10 Comparative Examples Measuring Items A B C D
Ti~ist Primary 450 540 450 450 (t/m) Final 700 760 700 700 m ickness (d) 365 360 375 365 Critical Sewing more than Speed (rpm) 5,500 2,000 4,500 5,000 M~chanical Before Breaking 4956 2340 1510 4891 Strength Sewing Strength (g) Breaking 8.7 23.0 27.0 10.5 Elongation (96) Stress (g/d) 13.6 6.5 4.0 13.4 ~fter Breaking 4956 1116 1474 4890 Sewing Strength (g) Breaking 8 7 17 2 30 5 10 5 Elongation (%) ' ' ' Breaking 13.6 3.1 3.6 13.4 Strength Retaining 100 47.5 90.0 100 ., ~,, ~
Conditions of the sewing tests are as follows:
1) Regarding the mechanical strength;
type of sewing machine: DDC-227 provided by JUKI MISHIN K.K.;
sewing needle: DBX 1 ~14;
sewing speed: 4,500 rpm; and fabric to be sewn: four-plied serge fabrics, each woven from a spun yarn consisting of polyester fiber (65%) and rayon fiber (35~);
2) Regarding the critical sewing speed;
type of sewing machine: the same type as above;
sewing needle: DBX 1 #18; and fabric to be sewn: eight-ply fabrics of the same type as above.
l~ Example 4 A filament tow of 7000 d/6000 f consisting of poly-meta-phenyleneisophthale amide fibers having no crimps ~as processed by the apparatus shown in Fig. 2.
The distance and the draw ratio between the feed rollers 2 and the stretch rollers 6 were adjusted to 600 mm and 26 times, respectively. The tow was stretch--broken to a staple fiber bundle having a mean fiber langth L of 230 mm and, inally, was formed into a fasciated yarn A of 20 S (cotton count) by adjusting the 2~ air pressures of the aspirator and the air nozzle to 4 kg/cm2 and 5 kg/cm2, respectively.
On the other hand, the same tow as described in Example 4, was cut to form staple fibers of 2 inch lengths after crimps were imparted by a stufer box 30 system, and the staple fibers were spun to become a spun yarn B as a comparative example by means of a conventional cotton spinning system.
Measurement was carried out on the two yarns A and B
regarding a tensile strength, results of which are shown 35 on the graph in Fig. 6.
As is apparent from the graph, the yarn A according to the present invention shows a dif~erent stress-strain curve ~rom that of the comparative yarn B.
Further, the creep durabilities of both the yarn A
and B were 0.5% and 5.0~, respectively.
Next, how the present invented yarn is utilized in the industrial material field, is explained.
The yarn according to the present invention can be utilized for a bag filter, because of its excellent mechanical strength and creep durability in a high temperature condition. Further, the yarn is suitable for a reinforcing member embedded in a mold material such as rubber because the yarn is rich in fluffs and in inter--fiber porosity which enhance the anchoring effect in the mold material~ The yarn also can be preferably utilized for sewing thread due to its heat radiation ability which serves to suppress the temperature elevation of a sewing needle even at a high sewing speed.
The above-mentioned effects will be more apparent by the following examples.
Example 5 A fasciated yarn of 20 S (cotton count)having a mean fiber length of 230 mm was prepared from a ilament tow of 7000 d/1000 f consisting of poly-meta-phenyleneiso-phthalamide fibers by utilizing the apparatus shown in Fig. ~.
A bag filter C according to the present invention was manufactured from a satin made of the abovesaid yarn.
Densities of the warp and weft were 73 ends/in and 57 picks/in, respectively.
On the other hand, another bag filter D was manu-factured from the same kind of fabric made of the yarn B
as described in Example 4 as a comparative example.
The two bag filters C and D were tested on air permeability and dimensional stability, results of which are tabulated in Table 2.
~ . .
.
Table 2 Air Permeability( ) Dimensional( ) (cc/cm2/sec)_ Stability (%) Note:
~l) The air permeability was measured according to JIS-L 1096-6-27-1-A.
(2) The dimensional stability was calculated from an elongation of the bag filter when being exposed in the atmosphere at a temperature of 200C under a load of 20 ~g~10 cm in width for 7 days.
Example 6 A fasciated yarn of 3.6 S (cotton count) was pro-duced, according to the present invention, from a filament tow of 150,000 d consisting of the same aromatic polyether amide fiber as utilized in Example 2 by means of the apparatus shown in Fig. 2, thereby being knit in a tubular braid. The braid was layered in a hose structure as an inner reinforcement 52 along with an inner rubber layer 51, a polyester filament fabric 53, and an outer ~5 rubber layer 54.
On the other hand, a filament yarn of 1500 d/1000 f consisting of the same polymer fiber as above was knit to form the same tubular braid and, thereafter, was incorpo-rated into a comparàtive hose structure instead of the abovesaid inner reinforcement 52.
Comparison of the two hoses in shown in Table 3.
5~
Table 3 Measured Item Processing Example 6 Comparative Oil Durability Untreated 1803 1712 ,(100)(100) (kglcm~)150C x 100 hr 1803 1712 (~) (100)(100) 150C x 200 hr 1785 1678 ~99) (98) 150C x 500 hr 1767 1644 (98) ~96) Wearability 83.5 68.2 ChemicalUntreated 100 100 Durability N2SO4 g9 96 NaOH 97 9~
Steam Untreated 100 100 Durability 150C x 500 hr 93.6 87,3 in steam The measurements of each item are as follows:
1. Oil Durability Three hoses to be tested were filled with brake oil and were left in the atmosphere at a temperature of 150C for 100, 200, and 500 hours, respectively. Each burst test was carried out on one of the hoses at each time period.
2. Wearability A hose to be tested was subjected to repeated bending motions caused by a pulley, on which the hose was mounted. The pulley had a diameter 15 times of the hose width and was rotated reciprocally at a rate of 10 mtsec.
After 2000 revolutions under a tension of 5 kg/cm, the breaking strength of the hose was measured.
~2~5~
From this value and the strength of the untreateed one, the strength retaining ratio was calculated.
3. Chemical Durabiity ~o hoses to be tested were immersed into a solution of ~0% sulfuric acid at 90C and a solution of 10~ caustic soda at 95C, respectively, for 100 hours From the breaking strengths or the treated hoses and the untreated one, the strength retaining ratios to each chemical were calculated.
4. Steam Durability Throu~h a hose to be tested, super heated steam of 150C was introduced for 500 hours. From the breaking strengths of the treated hose and the untreated hose, the strength retaining ratios were calculated.
Example 7 The same fasciated yarn of 3.6 S (cotton count) as obtained in Example 6 was two-plied with an S twist of 10 t/10 cm to form a cord according to the present inven-tion. The cord was immersed into a first bath, which was followed by drying at 150C for 1 minute and baking at 240C for 1 minute. Then, the cord was ~mmersed into a second bath which was followed by drying at 150C for 1 minute and baking at 240C for 1 minute, thereby obtaining a cohesive cord for a timing belt. Formulas of the first and second baths are as follows:
First bath Denacol ~ FX-611 (NAGASE SANGYO K K.) (sorbitolpolyglycidile ether) 6 parts 3~ Neocol ~ SW-30 (DAIICHI KOGYO SEIYAKU K.K.) (dioctylsulfosuccinate-natrium salt) 4 parts Hylene ~ MP (Du Pont De Nemours & Ço.) (phenol blocked 4,4'-diphenyle-methanediisocyanate) 60 parts 35Nipol ~ 2518FS (Nippon Zeon K.K.J
(vinylpyridine-styrene-butadiene polymer) 125 parts . _ . . .
' ' ~9L5~
Water 805 parts Total 1000 parts Second bath Resorein 15 parts Formalin ~37 weight~)17 parts Caustic Soda Solution (10 weight%) 6 parts Nipol ~ 251FS (40 weight%)400 parts Water 562 parts Total 1000 parts On the other hand, utilizing a filament yarn of 1500 d/1000 f consisting of the same aromatic polyether amide fibers as the above-said invented yarn, another cord was prepared, as a comparative example, according to the same process as described above.
Comparisons between the two cords and ~etween the two timing belts for automobile engine utilizing the each ~ord are shown in Table 4.
Table 4 Comparative Characteristics Example 7 Example ~ORD Breaking Strength (kg) 96 78 Young's Modulus (kg/d) 650 590 Pull-Out Force (kg/cm) 27 16 Wet Heat Durability (%) 98 95 BELT Wearability 100 hr 98 95 (%) 200 hr 96 85 Measurements of each item are as follows:
1. Breaking Strength and Young's Modulus These items were tested by means of a Tensiron st~ess-strain tester provided by TOYO-BALDWIN K.K.
2. Pull-Out Force ` ~
~2~58~
A two-plied cohesive cord to be tested was e~bedded in a rubber layer of 1 cm width composing a timing belt, so that the cord was directed perpendicular to the longitudinal direction of the belt. Then tne belt was vulcanized under a temperature of 160C for 20 minutes. A force was measured, which is necessary to pull out the cord from the structure of the vulcanized belt, at a rate of 200 cm/min.
3. ~et Heat Durability A cord to be tested was treated in an autoclave filled with steam of 150C (6 kg~cm2) for 100 hours.
The str~ngth retaining ratios were calculated from the breaking strengths of the treated cord and the untreated one.
1~ 4. Wearability A cord to be tested was subjected to repeated elongations of 6~ and compressions of 18~, caused by a ~oodrich type disc tester, for 100 hours or 200 hours.
The strength retainin~ ratios were calculated from the ~0 breaking strengths of the treated cord and the untreated one.
Example 8 The same fasciated yarn of 3.6 S (cotton count) as obtained in Example 6 was two-plied with a primary twist of 109 t/m and, then, the resultant yarn was three-plied with a final twist of 227 t/m to form a cord. The cord was incorporated into a V-belt as shown in Fig. 4, in wh~.ch reference numerals 41 and 45 designate cotton fabrics, respectively; 42 and 44 chloroprene rubber layers, respectively; and 43 the cord consisting of the invented yarns.
On the other hand, utilizing a filament yarn of 1500 d/1000 f consisting of the same aromatic polyether amide fibers as the invented yarn, another cord was prepared according to the same process as described above and was incorporated into another V-belt as a comparative example.
~ ~ "
Comparisons between the two V belts are shown in Table 5.
Table 5 Comparative Measured Item Example 8 Example Breaking Strength~kg) 1435 1404 Breaking Elongation~) 1.0 1.5 Young's Modulus(g/d) 540 480 Wearability ~kg) 1390 1260 Creep Durability (%) 0 0 Wet Heat Dimensional Stability (~) 0 0 Untreated 100 100 Chemical Durability (Strength retainingH2SO4 99 96 ratio) (~) NaOH 97 ~4 Measurements of each item are as follows:
1. Breaking Strength, Breaking Elongation, and Young's Modulus ~S These items were tested by means of a Tensiron stress-strain tester provided by TOYO-BALDWIN K.K..
2. Wearability The V-belt to be tested was subjected to repeated bendings caused by a pulley, on which the V-belt was mountted. The pulley had a diameter 15 times of the V-belt width and was rotated at a rate of 10 m/sec. After 109 revolutions in the atmosphere having a temperature of 16C and an RH of 65~ under a tension of 5 kg/cm, the breaking st~ength of the V-belt was measured and the strength retaining ratio was calculated relative to the untreated one.
3. Creep Durability ~5 A creep tester provided by K.K. IW~OTO
S~IS~USHO was utilized.
4. Wet Heat Dimensional Stability The V-belt to be tested was subjected to repeated bendings under conditions of 40C temperature and 100~ RH by the same device as utilized for testing the wearability. After 109 revolutions under a tension of 1 kg/cm, the dimensions of the V-belt were measured and compared to the original ones.
5. ~hemical Durability Two V-belts to be tested were immersed into aqueous solutions of 20% sulfuric acid at 95C, and 10 caustic soda at 95C, respectively, for 100 hours.
From breaking strengths of the teated V-belts and that of the untreated one, the strength retaining ratios to each chemical were obtained.
E~ample 9 The same fasciated yarn of 3.6 S (cotton count) as obtained in Example 6 was chopped to a plurality o pieces 2a of 5 mm in length. The chopped pieces were mixed with a heat durable rubber composition described in Table 6 with a weight ratio of 2.0:100, and the mixed composition was extruded through a slit to form a mold A in a sheet form of 3 mm in thickness. The mold A was processed, according ~5 to the following steps, to have a test piece: preparing two sheets of the above-said rubber composition not containing the chopped pieces, having thicknesses of 5 mm and 2 mm, respectively; interposing a canvas woven from a polyester yarn between the prepared two sheets to form a layered sample of 30 mm in width; peeling the rubber sheet of 5 mm in thickness along a 100 mm length and complementing a separately prepared rubber sheet of 2 mm in thickness of the same composition and the mold A of 3 mm in thickness in a layered manner to have a sample;
and vulcanizing the sample under a pressure of 50 kg/cm2 to make a finished test piece.
The test piece was subjected to repeated bendings of ~58'~
60 H~ by means of a hot pulley of 125C surface tempera-ture and a 75 mm diameter under a tension of 55 kg, and the time required to cause a crack on a surface of the test piece was measured.
On the other hand, as a comparative example, a mold B was prepared by utilizing a filament yarn of 15dO d/1000 f consisting of the same aromatic polyether amide fibers as the yarn utilized in the mold A, and another test piece was obtained in accordance with the 1~ same manner as described above and subjected to the ~racking test.
The results of the tests are tabulated in Table 7 showing data for two test pieces for each of the molds A
and B, one of which was prepared along an orientation of the chopped pieces and the other perpendicular thereto.
In this connection, the chopped pieces in the rubber composition are easily oriented along a flowing direction by being passed through a conduit in a fluid state before extrusion.
Table 6 Component Parts by weight Copolymerized rubber of 70 Ethylene-Hexafluoropropylene Copolymerized Rubber of 20 Ethylene-Propylene Chlorinated Butylic Rubber 10 Carbon 25 Zinc Oxide 5 Stearic Acid 0.5 Antioxidant ) 3 Peroxide ) 2.5 Triallylisocyanurate 1.5 Note: 1) mercaptobenzimidazol 2) PETROXIMON ~ F-400 (NIPPON YUSHI K.K.) Table 7 _ _ Orlentation Test Piece Cracking (hr) Example 9 87 Comparative 74 Example Example 9 61 Comparative 43 Example Example 10 A filament tow of 3000 denier consisting of the same aromatic polyether amide fibers as utilized in Example 2 ~ " .
~2~5~ ~
was processed by the apparatus shown in Fig. 2 to form a fasciated yarn A of 53 S (cotton count) according to the present invention. The yarn A was two-plied with a primary twist of S 700 t/m and the resultant yarn was three-plied with a final twist of Z 450 t/m, thereby obtaininq a sewing thread.
On the other hand, three comparative sewing threads B, C, and D consisting of a polyester filament yarn, a spun yarn of poly-meta-phenyleneisophthalate staple fibers of 50 mm length, and a filament yarn of the same aromatic polyether amide fibers as the yarn A, respec-tively, were prepared.
Sewing tests were carried out on the four sewing threads, and the results thereof are shown in Table 8.
It is apparent from Table 8 that the thread A
according to the present invention shows a constant mechanical strength throughout the sewing operation, and further suggests a possibility to endure a higher sewing rate than the one consisting of the filament yarn.
;~5~ ~
Table 8 Test Piece Example 10 Comparative Examples Measuring Items A B C D
Ti~ist Primary 450 540 450 450 (t/m) Final 700 760 700 700 m ickness (d) 365 360 375 365 Critical Sewing more than Speed (rpm) 5,500 2,000 4,500 5,000 M~chanical Before Breaking 4956 2340 1510 4891 Strength Sewing Strength (g) Breaking 8.7 23.0 27.0 10.5 Elongation (96) Stress (g/d) 13.6 6.5 4.0 13.4 ~fter Breaking 4956 1116 1474 4890 Sewing Strength (g) Breaking 8 7 17 2 30 5 10 5 Elongation (%) ' ' ' Breaking 13.6 3.1 3.6 13.4 Strength Retaining 100 47.5 90.0 100 ., ~,, ~
Conditions of the sewing tests are as follows:
1) Regarding the mechanical strength;
type of sewing machine: DDC-227 provided by JUKI MISHIN K.K.;
sewing needle: DBX 1 ~14;
sewing speed: 4,500 rpm; and fabric to be sewn: four-plied serge fabrics, each woven from a spun yarn consisting of polyester fiber (65%) and rayon fiber (35~);
2) Regarding the critical sewing speed;
type of sewing machine: the same type as above;
sewing needle: DBX 1 #18; and fabric to be sewn: eight-ply fabrics of the same type as above.
Claims (14)
1. A fasciated yarn consisting of staple fibers of a wholly aromatic polyamide polymer prepared by the stretch-breaking of a tow, comprising a core portion and a plurality of wrap fiber groups wrapped around said core portion, said yarn being characterized in that said staple fiber has a mean fiber length within the range of from 150 mm to 600 mm, a crimpability of less than 5%, and a mean degree of parallelism (?) of less than 3°, and that the number of said wrap fiber groups is within the range of from 0.5 to 20 per 1 cm in length of said yarn.
2. A fasciated yarn according to claim 1, in which said wholly aromatic polyamide polymer is selected from a group consisting of poly-para-phenyleneterephthalamide polymers, poly-meta-phenyleneisophthalamide polymers, and aromatic poly-etheramide polymers.
3. A method for producing a fasciated yarn con-sisting of staple fibers of a wholly aromatic polyamide polymer comprising the following steps of:
stretch-breaking a tow of filaments into a bundle of staple fibers taking care not to disturb the parallelism thereof, each filament of said tow having a crimpability of less than 5%; and subjecting said bundle of staple fibers, omitting a crimping process, to a fasciate spinning operation to form said fasciated yarn.
stretch-breaking a tow of filaments into a bundle of staple fibers taking care not to disturb the parallelism thereof, each filament of said tow having a crimpability of less than 5%; and subjecting said bundle of staple fibers, omitting a crimping process, to a fasciate spinning operation to form said fasciated yarn.
4. A method according to claim 3, in which said fasciate spinning operation is carried out under a non-slack state defined by a feed ratio of less than +4%, preferably less than +1% including a tension state.
5. A method according to claim 3, in which said staple fiber bundle is collectively guided by a trumpet shaped chute during said stretch-breaking operation.
6. A method according to claim 3, further com-prising the step of:
heating said fasciated yarn subsequent to said fasciate spinning operation.
heating said fasciated yarn subsequent to said fasciate spinning operation.
7. A method according to claim 3, in which said fasciate spinning operation is carried out by the false twisting action of a vortex.
8. A method according to claim 3, in which said wholly aromatic polyamide is selected from a group consisting of poly-para-phenyleneterephthalamide polymers, poly-meta-phenyleneisophthalamide polymers, and aromatic polyetheramide polymers.
9. A method according to claim 3, in which said tow has an oil content of within the range of from 0.05%
to 0.30% by weight thereof and a water content of less than 7.0% by weight thereof.
to 0.30% by weight thereof and a water content of less than 7.0% by weight thereof.
10. A method according to claim 9, in which said water content is less than 6.0% for said tow of said selected poly-para-phenyleneterephthalamide polymer.
11. A method according to claim 9, in which said water content is less than 3.0% for said tow of said selected aromatic polyetheramide polymer.
12. A fasciated yarn according to claim 1 in the form of a bag filter made from a fabric comprising said yarn.
13. A fasciated yarn according to claim 1 in a rubber product.
14. A fasciated yarn according to claim 1 in the form of a sewing thread.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000426179A CA1245841A (en) | 1983-04-19 | 1983-04-19 | Heat-durable spun-like fasciated yarn and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000426179A CA1245841A (en) | 1983-04-19 | 1983-04-19 | Heat-durable spun-like fasciated yarn and method for producing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1245841A true CA1245841A (en) | 1988-12-06 |
Family
ID=4125049
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000426179A Expired CA1245841A (en) | 1983-04-19 | 1983-04-19 | Heat-durable spun-like fasciated yarn and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1245841A (en) |
-
1983
- 1983-04-19 CA CA000426179A patent/CA1245841A/en not_active Expired
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