CA1055669A - Fibrous structures and process for the manufacture thereof - Google Patents
Fibrous structures and process for the manufacture thereofInfo
- Publication number
- CA1055669A CA1055669A CA218,863A CA218863A CA1055669A CA 1055669 A CA1055669 A CA 1055669A CA 218863 A CA218863 A CA 218863A CA 1055669 A CA1055669 A CA 1055669A
- Authority
- CA
- Canada
- Prior art keywords
- film
- fibres
- needles
- less
- fibrous structure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H13/00—Other non-woven fabrics
- D04H13/02—Production of non-woven fabrics by partial defibrillation of oriented thermoplastics films
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/42—Formation of filaments, threads, or the like by cutting films into narrow ribbons or filaments or by fibrillation of films or filaments
- D01D5/423—Formation of filaments, threads, or the like by cutting films into narrow ribbons or filaments or by fibrillation of films or filaments by fibrillation of films or filaments
-
- D—TEXTILES; PAPER
- D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
- D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
- D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
- D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
- D02G3/06—Threads formed from strip material other than paper
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H13/00—Other non-woven fabrics
Abstract
A B S T R A C T
A fibrous structure of coherent film fibres, of which at least 50% have a dimensional ratio Or 1.5 or less and at least 70% have a dimensional ratio of 2.0 or less, and a process for the manufacture of such fibrous structure comprising contacting a stretched film of a molecularly orientable thermo-plastic polymer having a thickness of 100 microns or less with needles of which the points rotate in the same direction as the movement of the film at the area of contact, with a circumferential speed of 10-60 times the linear speed of the film material, the axis of rotation being in transverse direction and at least some of the said needles being arranged in rows having a needle density of at least 15 per cm.
A fibrous structure of coherent film fibres, of which at least 50% have a dimensional ratio Or 1.5 or less and at least 70% have a dimensional ratio of 2.0 or less, and a process for the manufacture of such fibrous structure comprising contacting a stretched film of a molecularly orientable thermo-plastic polymer having a thickness of 100 microns or less with needles of which the points rotate in the same direction as the movement of the film at the area of contact, with a circumferential speed of 10-60 times the linear speed of the film material, the axis of rotation being in transverse direction and at least some of the said needles being arranged in rows having a needle density of at least 15 per cm.
Description
~LO3S5~ ` ~ :
The inven~ion relates to a novel fibrous structure ~ ~
.
of coherent film fibres having a square or nearly square cross-seGtion. The invention also relates to a process . .. .
for the manufacture of such fibrous structures.
It is known to manufacture fibres of thermoplastic polymeric material by spinning~ i.e., by extruding a melt of the thermoplastic polymer through a spinneret.
Such spun fibres have, generally speaking, a transverse cross-section of non-angular shape and in most cases even a circular cross-section. It is also known to manu-facture thermoplastic polymeric fibres from the base material by routes involving film splitting. In such routes the molten thermoplastic polymer is extruded through a linear or annular slit to form a film which is thereafter converted into a fibrous product of fibres with or without interconnectionO In order to carry out such conversion the film may, for instancel be subjected to a process known in the art as mechanical fibrillation, i.e., the film is ~irst stretched to effect molecular orientation and subsequently subjected to a mechanical treatment, such i as passing it over a rotating cylinder provided on its surface with needles~
The above-mentioned known process of mechanical fibrillation yields a fibrous product which is composed of flat fibres~ i.e., the cross-section of such fibres is not
The inven~ion relates to a novel fibrous structure ~ ~
.
of coherent film fibres having a square or nearly square cross-seGtion. The invention also relates to a process . .. .
for the manufacture of such fibrous structures.
It is known to manufacture fibres of thermoplastic polymeric material by spinning~ i.e., by extruding a melt of the thermoplastic polymer through a spinneret.
Such spun fibres have, generally speaking, a transverse cross-section of non-angular shape and in most cases even a circular cross-section. It is also known to manu-facture thermoplastic polymeric fibres from the base material by routes involving film splitting. In such routes the molten thermoplastic polymer is extruded through a linear or annular slit to form a film which is thereafter converted into a fibrous product of fibres with or without interconnectionO In order to carry out such conversion the film may, for instancel be subjected to a process known in the art as mechanical fibrillation, i.e., the film is ~irst stretched to effect molecular orientation and subsequently subjected to a mechanical treatment, such i as passing it over a rotating cylinder provided on its surface with needles~
The above-mentioned known process of mechanical fibrillation yields a fibrous product which is composed of flat fibres~ i.e., the cross-section of such fibres is not
-2-.
',' : ' ' ' :.: ' ' .... ..
l~SS~6~
only trapezoidal and t~refore angular in shape but their width, being referred to as the longest side of the cross-sectional quadrangle, is several times longer than their thickness, which latter term indicates the cross-sectional dimension perpendicular to that longest side. Many mechanical fibrillation methods, however, yield fibres t having a rectangular or substantially rectangular cross-- section and it will be clear that in such instances the terms width and thickness simply denote the longest and the shortest side of the rectangle, respectively.
Although in many cases the known mechanical fibrillation process and other known methods involving film splitting offer important advantages over spinneret-extrusion and ~hilst f'ilm fibres (i.e., f'ibres made from film) may be useful and sometimes even preferable for certain end-use applications, commercial acceptance of such fibres, particularly in the low denier range, has in some cases -been hampered by properties which to a certain extent seem inherent to the flat cross-sectional shape of the fibres, such as gloss, less constant crimp, and moderate resilience.
It will be clear that these disadvantages are circumvented or at least considerably reduced by film fibres having a high degree of cross-sectional "squareness", but so far such fibres have not been made available or described. : ~
' . . ,~:
',' : ' ' ' :.: ' ' .... ..
l~SS~6~
only trapezoidal and t~refore angular in shape but their width, being referred to as the longest side of the cross-sectional quadrangle, is several times longer than their thickness, which latter term indicates the cross-sectional dimension perpendicular to that longest side. Many mechanical fibrillation methods, however, yield fibres t having a rectangular or substantially rectangular cross-- section and it will be clear that in such instances the terms width and thickness simply denote the longest and the shortest side of the rectangle, respectively.
Although in many cases the known mechanical fibrillation process and other known methods involving film splitting offer important advantages over spinneret-extrusion and ~hilst f'ilm fibres (i.e., f'ibres made from film) may be useful and sometimes even preferable for certain end-use applications, commercial acceptance of such fibres, particularly in the low denier range, has in some cases -been hampered by properties which to a certain extent seem inherent to the flat cross-sectional shape of the fibres, such as gloss, less constant crimp, and moderate resilience.
It will be clear that these disadvantages are circumvented or at least considerably reduced by film fibres having a high degree of cross-sectional "squareness", but so far such fibres have not been made available or described. : ~
' . . ,~:
- 3- :
~ j:
: ~ ' , , , , , ' ` , ~
.. . . . .. . .
~.
~SS669 ~;
Accordingly, the invention provides a fibrous structure of . `
coherent film fibres, in which at least 70% of the fibres have a width/ ; ;
thickness ratio of 1.5 or less and in which each of the fibres has a denier of 10 or less.
The term "dimensional ratio" as used in this specification indicates the ratio between width and thickness, both used in the meaning as explained above.
Preferably, at least 70% of the fibres contained in the fibrous structure according to the invention have a dimensional ratio o~ 1.5 or less.
The advantages of the fibrous structure as now proposed are most evident in the lower fibre denier range. Accordingly, fibrous structures consisting of fibres having a denier per filament (dpf~ of 10 or less are preferred. In most cases an average dpf of 6 or less is found to be advantageous with respect to further processing the fibrous structures, whilst an average dpf of 4 or less is particularly preferred.
A particular advantage of the presently proposed fibrous structure in the lower fibre denier range is the absence of even small amounts of heavy denier fibres. The latter have been known to occur in some of the film fibrillates produced by previously descrlbed film splittine methods, and this phenomenon has been regarded in the past as one of the main disadvantages of film fibres as compared with spun fibres.
..
1~56~
In view of the narrow denier distribution combined with - the low fibre denier in the presently proposed fibrous structure the latter is particularly suitable for blend- `
ing with cotton and/or wool. Such blending may be effected in any of the known systems of staple fibre processing.
Open-end spinning may advantageously be applied for that purpose.
The invention also encompasses articles comprising the novel fibrous structures as hereinbefore described.
Such articles not only include yarns and other textile !~' materials (such as woven, knitted or non-woven fabric,3) as well as ropes, cordage, upholstery, and floor oovering, but also materials beyond the textile field, e.g., cellulosic 0:? synthetic paper and fibre-reinforced concrete. Parti-~cularly preferred articles of the sald type are yarns comprising the novel fibrous structur~sblended with cotton and/or wool, and textile materials comprising such yarns.
As mentioned above, the invention also relates to a process for the manufacture of the novel fibrous structures as hereinbefore described, in which a film material of a molecularly orientable thermoplastic polymer having a `
thickness of 100 microns or less is longitudinally stretched, -transported in the longitudinal direction, and contac~ed ;i.
with a plurality of needles bf which the points rotate in the same direction as the movement of the film at the area ~ .
`: ' ~5~ ~ ~
,' ~ .:
~55669 of contact, with a circumferential spee~ of 10~60 times the linear speed of the film material, the axis of rotation being in transverse direction and at least some o~ the said needles being arranged in rows having a needle density of at least 15 per cm.
The product obtained after the contacting of the film material with the needles in the manner as described may be collected as such for further processing but in many cases it is preferred to subject it to a stretch-breaking treatment subsequent to the contacting with the needles in order to reduce the length of the fibres contained in the structure to the ~esired staple length. Although other methods to reduce the fibre length, i.e., cutting with suit-able means, can also be employed before or during the further processing, stretch-breaking can be effected without destroy-ing cohesion between the fibres in the fibrous structure.
The film material as used in the process according to the invention may be a single film, the term film including tape, ribbon or the like, or it may be a multiple film, -i.e., a film consisting of two or more layers in overlying relationship, each layer being connected to the adjacent layer or layers. In both instances a number of single or multiple films may be simultaneously processed in side-by-side andior overlying relationship, and particularly-in ~5 -~e oommercial operation of the present process to manu-.
~055669 :.
facture fibrous products composed of low denier fibres it is found to be advantageous to use, as the film material, 2-6 films in overlying relationship by con-tacting them simultaneously with the needles, the use in such manner of 4 films being particularly preferred ~ -in some cases. ~ i The needles may comprise, for example, needles, pins teeth of pointed or bladed strips, wires, or wire bristles.
In most cases the needles are positioned in such a way that they have a rearward inclination with respect to the direction of the rotation, which inclination facilitates the disengagement of the needles from the film material after their contact therewith. Suitable needle inclination ;~
angles are within the range of 10-40 degrees, an angle of 3 degrees being generally satisfactory. ~ ~
A suitable method of carrying out the process of the in-vention is to pass the stretched film material under tension over a rotating cylinder, for instance a roller or drum, provided with needles disposed on its surface in rows.
The rows of needles may be straight or bent and may extend to the whole width of the film material to be processed or may be considerably shorter, although in the latter event they should, of course, be present in sufficient number to ascertain contact with needles over the whole width of the film material. Helical rows extending over the `~
'" ' ... .
, .
`~.
cylindrical surface or axial bands of short non-axial rows are suitably employed in some cases. Particularly preferred is the use of a cylinder having axial or substantially axial rows of needles, and under the required process conditions as indicated hereinbefore such use yields a fibrous structure of attractive appearance, being composed of fibres having only a limited number of highly irregular interconnections whilst complying with the above-mentioned ~ -- dimensional requirements.
The operating conditions Or the present process may be varied in many other respects. A speed ratio, i.e., the ratio between the circumferential speed of the needle points and the linear speed of the film material, within the range of 25-40 is advantageously used ln many cases, ~a speed ratio of 30-35 being particularly preferred.
Suitable linear speeds of the film material are normally within the range of 3-20 m/min. and preferably within the ;
range of 5-15 m/min. It has been found that rows having a needle density (i.e., the number of needles per cm) ;
of 20-40 may favourably affect the performance of the ~
present process, whilst generally a needle density of ~ ' 25-35 is most preferred. Particularly advantageous are rows of oval or flat needles arranged with their longest cross-sectional dimension in longitudinal direction, i.e., , in the same or substantially the same ùirection as the . .
`:~
, i . .
:
~55669 :
movement Or the film material. In certain cases two co~
operating contra-rotating rollers with intermeshing straight axial rows of needles and the same rotational speed are suitably used.
The film material as used in the process O:e the in-vention may consist of any thermoplastic polymer which, as indicated hereinbefore, can be molecularly oriented by stretching. Many polymeric materials may suitably be used, for example, homo- and copolymers of vinyl chloride, vinylidene chloride, vinyl acetate, and acrylonltrile, as well as polyesters, polyamides, and polylactones, such as polypivalolactone. Preferred polymeric materlals in¢lude jl.
homo- and copolymers of mono-olefins, such as ethylene and propylene. Film material containing at least 80%w of polypropylene, low pressure polyethylene or a blend thereof ;-is particularly preferred, whilst in some cases additional advantages are obtained if in addition to the said poly-olefin(s) the film material contains 2-20%w of a homo-polymer or block copolymer of butadiene and/or 0.1-~%w of a slip agent. The indication "%w" as used in this specification means percentage by weight with respect to the total composition.
It will be appreciated that two or more different thermoplastic polymers may suitably be used in embodiments of the present process already mentioned hereinbefore, . : .....
;, ~
:.
'' ' ~'''' tC115566~
which involve the processing of a multiple film or of a plurality of single or multiple films in side-by-side and/or overlying relationship. In such cases a bi- or multi-component fibrous structure is obtained. Under suitable conditions such product is particularly at-tractive for further processing in view of its bulk~
owing to spontaneous or heat-induced crimping properties of the fibrous structure or at least a major part of the fibres thereofO
The invention may be illustrated by the following non-restrictive Examples.
E;xampïe _l ' ' .
A film of a polypropylene having a melt index of 105 j.:-(expressed in g/10 min.; determined according to ASTM
D 1238-70, condition E) was extruded via the blown film route in a thickness of 50 microns for each layer of the lay-flat film. The film was stretched at 135 C at a stretch ratio of 1:8 after being cut into tapes having a width of 10 cm.
The stretched film material tdouble layer) was passed at a linear speed of S m/min. over a roller equipped with 6 equispaced axial rows of needles and rotating at a !' .
peripheral speed of 200 m/min.~ each row having a needle density of 32.
l~SS669 A fîbrous structure was obtained consisting of fibres ~
within the denier range of 3.2-6.5, 60% of the fibres ,.
having a dimensional ratio (DR) between 1 and 1l5 and 80%
of the fibres having a DR bet~een 1 and 200.
Exam~le 2 .
Starting from the extruded film as described in Example 1~ a 4-layer system was made by cutting and stretching two lay-flat films under the above-mentioned ~ `
conditions. : ~ .
The stretched film material was fibrillated under the condit:ions as mentioned in Example 1 except a peripheral roller speed of 150 m/minO and a needle density of 39. ..
A fibrous product having the same characterizing .:
features as those given in ~xample 1 was obtained.
A film of the polypropylene as used in Example 1 was ..
extruded in a thickness of 40 microns and subsequently converted into a 4-layer stretched film material and fibrillated as described in Example 2.
A fibrous product was obtained consisting of fibres within ;.
the denier range of 1~8 and 3.7~ whilst 65% of the fibres ~ .
had a DR between 1 and 1.5 and 83% had a DR between 1 and 2.
Example 4 .:
A blend was made by dry tumble mixing the following composition:
~055ti~i9 : .
87%w of the polypropylene as used in Example 1; :
10%w of granulated "CARIFLEX"-TR 1101 (a styrene-butadiene block copolymer), and ,~.
~ 3%w of "UNISLIP" (a slip agent).
This blend was extruded into a lay-flat film, cut, stretched and fibrillated under the conditions as given -in Example 1 except a peripheral roller speed Or 150 m/min. . .
A fibrous product was obtained consisting of very . :
soft hand fibres within the denier range of 3.2-4.9, ~:
82% of the fibres having a DR between 1 and 1.5.
EXAMPLE 5 ..
, Starting from the blend as used in Example 4, the procedure of Example 3 was repeated, yielding a fibrous product consisting of very soft hand fibres within the denier range of 1.8-2.7, whilst 85% of the fibres had a j~
DR between 1 and 1.5. : ~;
'^:
. ~ . , , '.
`
, -12- ~
. '.
.. . .
. , .
. .
'. ' ' : ' ~ ~ ~ , '' ' . ' ' '~ -
~ j:
: ~ ' , , , , , ' ` , ~
.. . . . .. . .
~.
~SS669 ~;
Accordingly, the invention provides a fibrous structure of . `
coherent film fibres, in which at least 70% of the fibres have a width/ ; ;
thickness ratio of 1.5 or less and in which each of the fibres has a denier of 10 or less.
The term "dimensional ratio" as used in this specification indicates the ratio between width and thickness, both used in the meaning as explained above.
Preferably, at least 70% of the fibres contained in the fibrous structure according to the invention have a dimensional ratio o~ 1.5 or less.
The advantages of the fibrous structure as now proposed are most evident in the lower fibre denier range. Accordingly, fibrous structures consisting of fibres having a denier per filament (dpf~ of 10 or less are preferred. In most cases an average dpf of 6 or less is found to be advantageous with respect to further processing the fibrous structures, whilst an average dpf of 4 or less is particularly preferred.
A particular advantage of the presently proposed fibrous structure in the lower fibre denier range is the absence of even small amounts of heavy denier fibres. The latter have been known to occur in some of the film fibrillates produced by previously descrlbed film splittine methods, and this phenomenon has been regarded in the past as one of the main disadvantages of film fibres as compared with spun fibres.
..
1~56~
In view of the narrow denier distribution combined with - the low fibre denier in the presently proposed fibrous structure the latter is particularly suitable for blend- `
ing with cotton and/or wool. Such blending may be effected in any of the known systems of staple fibre processing.
Open-end spinning may advantageously be applied for that purpose.
The invention also encompasses articles comprising the novel fibrous structures as hereinbefore described.
Such articles not only include yarns and other textile !~' materials (such as woven, knitted or non-woven fabric,3) as well as ropes, cordage, upholstery, and floor oovering, but also materials beyond the textile field, e.g., cellulosic 0:? synthetic paper and fibre-reinforced concrete. Parti-~cularly preferred articles of the sald type are yarns comprising the novel fibrous structur~sblended with cotton and/or wool, and textile materials comprising such yarns.
As mentioned above, the invention also relates to a process for the manufacture of the novel fibrous structures as hereinbefore described, in which a film material of a molecularly orientable thermoplastic polymer having a `
thickness of 100 microns or less is longitudinally stretched, -transported in the longitudinal direction, and contac~ed ;i.
with a plurality of needles bf which the points rotate in the same direction as the movement of the film at the area ~ .
`: ' ~5~ ~ ~
,' ~ .:
~55669 of contact, with a circumferential spee~ of 10~60 times the linear speed of the film material, the axis of rotation being in transverse direction and at least some o~ the said needles being arranged in rows having a needle density of at least 15 per cm.
The product obtained after the contacting of the film material with the needles in the manner as described may be collected as such for further processing but in many cases it is preferred to subject it to a stretch-breaking treatment subsequent to the contacting with the needles in order to reduce the length of the fibres contained in the structure to the ~esired staple length. Although other methods to reduce the fibre length, i.e., cutting with suit-able means, can also be employed before or during the further processing, stretch-breaking can be effected without destroy-ing cohesion between the fibres in the fibrous structure.
The film material as used in the process according to the invention may be a single film, the term film including tape, ribbon or the like, or it may be a multiple film, -i.e., a film consisting of two or more layers in overlying relationship, each layer being connected to the adjacent layer or layers. In both instances a number of single or multiple films may be simultaneously processed in side-by-side andior overlying relationship, and particularly-in ~5 -~e oommercial operation of the present process to manu-.
~055669 :.
facture fibrous products composed of low denier fibres it is found to be advantageous to use, as the film material, 2-6 films in overlying relationship by con-tacting them simultaneously with the needles, the use in such manner of 4 films being particularly preferred ~ -in some cases. ~ i The needles may comprise, for example, needles, pins teeth of pointed or bladed strips, wires, or wire bristles.
In most cases the needles are positioned in such a way that they have a rearward inclination with respect to the direction of the rotation, which inclination facilitates the disengagement of the needles from the film material after their contact therewith. Suitable needle inclination ;~
angles are within the range of 10-40 degrees, an angle of 3 degrees being generally satisfactory. ~ ~
A suitable method of carrying out the process of the in-vention is to pass the stretched film material under tension over a rotating cylinder, for instance a roller or drum, provided with needles disposed on its surface in rows.
The rows of needles may be straight or bent and may extend to the whole width of the film material to be processed or may be considerably shorter, although in the latter event they should, of course, be present in sufficient number to ascertain contact with needles over the whole width of the film material. Helical rows extending over the `~
'" ' ... .
, .
`~.
cylindrical surface or axial bands of short non-axial rows are suitably employed in some cases. Particularly preferred is the use of a cylinder having axial or substantially axial rows of needles, and under the required process conditions as indicated hereinbefore such use yields a fibrous structure of attractive appearance, being composed of fibres having only a limited number of highly irregular interconnections whilst complying with the above-mentioned ~ -- dimensional requirements.
The operating conditions Or the present process may be varied in many other respects. A speed ratio, i.e., the ratio between the circumferential speed of the needle points and the linear speed of the film material, within the range of 25-40 is advantageously used ln many cases, ~a speed ratio of 30-35 being particularly preferred.
Suitable linear speeds of the film material are normally within the range of 3-20 m/min. and preferably within the ;
range of 5-15 m/min. It has been found that rows having a needle density (i.e., the number of needles per cm) ;
of 20-40 may favourably affect the performance of the ~
present process, whilst generally a needle density of ~ ' 25-35 is most preferred. Particularly advantageous are rows of oval or flat needles arranged with their longest cross-sectional dimension in longitudinal direction, i.e., , in the same or substantially the same ùirection as the . .
`:~
, i . .
:
~55669 :
movement Or the film material. In certain cases two co~
operating contra-rotating rollers with intermeshing straight axial rows of needles and the same rotational speed are suitably used.
The film material as used in the process O:e the in-vention may consist of any thermoplastic polymer which, as indicated hereinbefore, can be molecularly oriented by stretching. Many polymeric materials may suitably be used, for example, homo- and copolymers of vinyl chloride, vinylidene chloride, vinyl acetate, and acrylonltrile, as well as polyesters, polyamides, and polylactones, such as polypivalolactone. Preferred polymeric materlals in¢lude jl.
homo- and copolymers of mono-olefins, such as ethylene and propylene. Film material containing at least 80%w of polypropylene, low pressure polyethylene or a blend thereof ;-is particularly preferred, whilst in some cases additional advantages are obtained if in addition to the said poly-olefin(s) the film material contains 2-20%w of a homo-polymer or block copolymer of butadiene and/or 0.1-~%w of a slip agent. The indication "%w" as used in this specification means percentage by weight with respect to the total composition.
It will be appreciated that two or more different thermoplastic polymers may suitably be used in embodiments of the present process already mentioned hereinbefore, . : .....
;, ~
:.
'' ' ~'''' tC115566~
which involve the processing of a multiple film or of a plurality of single or multiple films in side-by-side and/or overlying relationship. In such cases a bi- or multi-component fibrous structure is obtained. Under suitable conditions such product is particularly at-tractive for further processing in view of its bulk~
owing to spontaneous or heat-induced crimping properties of the fibrous structure or at least a major part of the fibres thereofO
The invention may be illustrated by the following non-restrictive Examples.
E;xampïe _l ' ' .
A film of a polypropylene having a melt index of 105 j.:-(expressed in g/10 min.; determined according to ASTM
D 1238-70, condition E) was extruded via the blown film route in a thickness of 50 microns for each layer of the lay-flat film. The film was stretched at 135 C at a stretch ratio of 1:8 after being cut into tapes having a width of 10 cm.
The stretched film material tdouble layer) was passed at a linear speed of S m/min. over a roller equipped with 6 equispaced axial rows of needles and rotating at a !' .
peripheral speed of 200 m/min.~ each row having a needle density of 32.
l~SS669 A fîbrous structure was obtained consisting of fibres ~
within the denier range of 3.2-6.5, 60% of the fibres ,.
having a dimensional ratio (DR) between 1 and 1l5 and 80%
of the fibres having a DR bet~een 1 and 200.
Exam~le 2 .
Starting from the extruded film as described in Example 1~ a 4-layer system was made by cutting and stretching two lay-flat films under the above-mentioned ~ `
conditions. : ~ .
The stretched film material was fibrillated under the condit:ions as mentioned in Example 1 except a peripheral roller speed of 150 m/minO and a needle density of 39. ..
A fibrous product having the same characterizing .:
features as those given in ~xample 1 was obtained.
A film of the polypropylene as used in Example 1 was ..
extruded in a thickness of 40 microns and subsequently converted into a 4-layer stretched film material and fibrillated as described in Example 2.
A fibrous product was obtained consisting of fibres within ;.
the denier range of 1~8 and 3.7~ whilst 65% of the fibres ~ .
had a DR between 1 and 1.5 and 83% had a DR between 1 and 2.
Example 4 .:
A blend was made by dry tumble mixing the following composition:
~055ti~i9 : .
87%w of the polypropylene as used in Example 1; :
10%w of granulated "CARIFLEX"-TR 1101 (a styrene-butadiene block copolymer), and ,~.
~ 3%w of "UNISLIP" (a slip agent).
This blend was extruded into a lay-flat film, cut, stretched and fibrillated under the conditions as given -in Example 1 except a peripheral roller speed Or 150 m/min. . .
A fibrous product was obtained consisting of very . :
soft hand fibres within the denier range of 3.2-4.9, ~:
82% of the fibres having a DR between 1 and 1.5.
EXAMPLE 5 ..
, Starting from the blend as used in Example 4, the procedure of Example 3 was repeated, yielding a fibrous product consisting of very soft hand fibres within the denier range of 1.8-2.7, whilst 85% of the fibres had a j~
DR between 1 and 1.5. : ~;
'^:
. ~ . , , '.
`
, -12- ~
. '.
.. . .
. , .
. .
'. ' ' : ' ~ ~ ~ , '' ' . ' ' '~ -
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A fibrous structure of coherent film fibres, in which at least 70% of the fibres have a width/thickness ratio of 1.5 or less and in which each of the fibres has a denier of 10 or less.
2. A fibrous structure as claimed in claim 1, in which the fibres have an average denier per fibre of 6 or less.
3. A fibrous structure as claimed in claim 2, in which the average denier per fibre is 4 or less.
4. A process for the manufacture of a fibrous structure of coherent film fibres in which a film material of a molecularly orientable thermo-plastic polymer having a thickness of 100 microns or less is longitudinally stretched, transported in the longitudinal direction, and contacted with a plurality of needles of which the points rotate in the same direction as the movement of the film at the area of contact, the axis of rotation being in transverse direction and at least some of the said needles being arranged in rows characterized in that the number of needles in the rows is 20-40 per cm and the ratio between the circumferential speed of the needles and the linear speed of the film is 10-60.
5. A process as claimed in claim 4, in which 2-6 films in overlying relationship are used as the film material by contacting the said films simultaneously with the needles.
6. A process as claimed in claim 4, in which the speed ratio between the needle points and the film material is 25-40.
7. A process as claimed in claim 6, in which the said speed ratio is 30-35.
8. A process as claimed in claim 4, in which the rows have a needle density of 25-30.
9. A process as claimed in any one of claims 4, 5 or 6, in which rows of oval or flat needles arranged with their longest cross-sectional dimension in longitudinal direction are used.
10. A process as claimed in claim 4, in which at least 80%w of the thermoplastic polymeric material is polypropylene, law-pressure polyethylene, or a blend thereof.
11. A process as claimed in claim 10, in which the film material contains 2-20%w of a homopolymer or block copolymer of butadiene.
12. A process as claimed in claim 10 or 11, in which the film contains 0.1-4/w of a slip agent.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB6857/74A GB1497540A (en) | 1974-02-14 | 1974-02-14 | Fibrous structures and process for the manufacture thereo |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1055669A true CA1055669A (en) | 1979-06-05 |
Family
ID=9822029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA218,863A Expired CA1055669A (en) | 1974-02-14 | 1975-01-28 | Fibrous structures and process for the manufacture thereof |
Country Status (14)
| Country | Link |
|---|---|
| AR (1) | AR210989A1 (en) |
| BE (1) | BE825425A (en) |
| BR (1) | BR7500794A (en) |
| CA (1) | CA1055669A (en) |
| DE (1) | DE2505710B2 (en) |
| ES (1) | ES434656A1 (en) |
| FR (1) | FR2261128B1 (en) |
| GB (1) | GB1497540A (en) |
| HU (1) | HU174505B (en) |
| IE (1) | IE40637B1 (en) |
| IT (1) | IT1030126B (en) |
| NL (1) | NL7501632A (en) |
| NO (1) | NO143032C (en) |
| ZA (1) | ZA75889B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL7909299A (en) * | 1979-12-22 | 1981-07-16 | Stamicarbon | METHOD FOR MANUFACTURING NETWORK PACKAGES. |
| NL7909298A (en) * | 1979-12-22 | 1981-07-16 | Stamicarbon | METHOD FOR MANUFACTURING OBJECTS FROM WATER-HARDENED MATERIAL |
| US5578373A (en) * | 1990-11-01 | 1996-11-26 | Nippon Oil Co., Ltd. | Split polyethylene stretched material and process for producing the same |
| JP3027225B2 (en) * | 1991-05-27 | 2000-03-27 | 日石三菱株式会社 | Manufacturing method of prepreg |
-
1974
- 1974-02-14 GB GB6857/74A patent/GB1497540A/en not_active Expired
-
1975
- 1975-01-28 CA CA218,863A patent/CA1055669A/en not_active Expired
- 1975-02-07 BR BR794/75A patent/BR7500794A/en unknown
- 1975-02-10 HU HU75SE1766A patent/HU174505B/en unknown
- 1975-02-12 FR FR7504320A patent/FR2261128B1/fr not_active Expired
- 1975-02-12 NO NO750451A patent/NO143032C/en unknown
- 1975-02-12 ZA ZA00750889A patent/ZA75889B/en unknown
- 1975-02-12 IE IE274/75A patent/IE40637B1/en unknown
- 1975-02-12 ES ES434656A patent/ES434656A1/en not_active Expired
- 1975-02-12 NL NL7501632A patent/NL7501632A/en unknown
- 1975-02-12 IT IT67366/75A patent/IT1030126B/en active
- 1975-02-12 AR AR257602A patent/AR210989A1/en active
- 1975-02-12 BE BE1006452A patent/BE825425A/en unknown
- 1975-02-12 DE DE2505710A patent/DE2505710B2/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| IE40637L (en) | 1975-08-14 |
| IT1030126B (en) | 1979-03-30 |
| NO143032C (en) | 1980-12-03 |
| ZA75889B (en) | 1976-01-28 |
| BR7500794A (en) | 1975-11-25 |
| AR210989A1 (en) | 1977-10-14 |
| BE825425A (en) | 1975-08-12 |
| FR2261128A1 (en) | 1975-09-12 |
| NL7501632A (en) | 1975-08-18 |
| AU7812575A (en) | 1976-08-12 |
| DE2505710B2 (en) | 1979-11-22 |
| ES434656A1 (en) | 1976-12-16 |
| IE40637B1 (en) | 1979-07-18 |
| NO143032B (en) | 1980-08-25 |
| GB1497540A (en) | 1978-01-12 |
| HU174505B (en) | 1980-01-28 |
| NO750451L (en) | 1975-08-15 |
| FR2261128B1 (en) | 1978-03-10 |
| DE2505710A1 (en) | 1975-08-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3914365A (en) | Methods of making network structures | |
| US4814131A (en) | Process for producing a shaped article, such as fiber composed of a hydrophobic polymer and a hydrophilic polymer | |
| US3365872A (en) | Yarn wrapped with surface fibers locked in place by core elements | |
| US4420534A (en) | Conductive composite filaments and methods for producing said composite filaments | |
| US6109015A (en) | Process for making poly(trimethylene terephthalate) yarn | |
| US3705070A (en) | Nonwoven fabric and process for preparing | |
| US3470685A (en) | Synthetic textile yarn | |
| US4457973A (en) | Conductive composite filaments and methods for producing said composite filaments | |
| US3496260A (en) | Method for producing fibrous web from polymer film | |
| US3621646A (en) | Composite fibrid yarns and method of manufacture | |
| JP2002505718A (en) | Composite yarn with high cutting resistance for demanding services | |
| US2980982A (en) | Fibrous article | |
| US2399260A (en) | Filamentous product | |
| CA1055669A (en) | Fibrous structures and process for the manufacture thereof | |
| US4274251A (en) | Yarn structure having main filaments and tie filaments | |
| US4207375A (en) | Network structures and methods of making same | |
| AU606357B2 (en) | Biconstituent polypropylene/polyethylene fibers | |
| US4144368A (en) | Network structures having different cross-sections | |
| US3796035A (en) | Semi-continuous filament combination yarn | |
| US4102969A (en) | Method for manufacturing crimped textile elements by fibrillation of films | |
| US3641760A (en) | Foam fibrillated yarn and process | |
| US4182606A (en) | Slit extrusion die | |
| US4179875A (en) | High tenacity, low denier poly(ethylene terephthalate) fibrillated tape yarn | |
| US3422616A (en) | Manufacture of threads,cords,ropes and like articles | |
| US4036003A (en) | Poly(ethylene terephthalate) fibrillated tape sewing thread |