CA1075870A - Process and apparatus for stretching a non-woven web of an orientable polymeric material - Google Patents
Process and apparatus for stretching a non-woven web of an orientable polymeric materialInfo
- Publication number
- CA1075870A CA1075870A CA249,031A CA249031A CA1075870A CA 1075870 A CA1075870 A CA 1075870A CA 249031 A CA249031 A CA 249031A CA 1075870 A CA1075870 A CA 1075870A
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- Prior art keywords
- web
- rollers
- velocity
- stretching
- interdigitating
- Prior art date
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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
- D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
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- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Nonwoven Fabrics (AREA)
- Treatment Of Fiber Materials (AREA)
Abstract
Process and Apparatus For Stretching A Non-Woven Web of An Orientable Polymeric Material Abstract of the Disclosure There is described in a preferred embodiment of the present invention, a process and apparatus of bi-axially stretching a non-woven web of synthetic fibers in a first and second station wherein the first and second stations are provided with sets of rolls having grooves parallel and perpendicular, respectively, to the axis of each set of rolls. The groove pattern of the rolls is generally a sinosoidal wave the web basis weight in grams per square meter.
Description
~L075870 This invention relates to a novel process and apparatus Eor the stretching oE non-woven and spun-bonded webs of synthetic fibers to improve the strength thereof and more particularly to a novel process and apparatus Eor the bi-axial stretching of non-woven webs of orientable, polymeric fibers.
Background of the Invention Many non-woven and (continuous filament) spun-bonded fabrics or webs have found use in the market as substitutes for textile materials. Such webs consist of randomly laid fibers, either in the form of short staple lengths or continuous fila-ments, which are undrawn or only partially drawn, and have there~
fore not obtained their optimum strength. Conventional methods of web stretching, such as Goudet-roll stretching and lateral stretching in tenter-frames, do not lend themselves to stretching of such webs. In longitudinal roll stretching a narrowing of the web occurs, the individual fibers between bcnding points do not undergo molecular orientation. In lateral tenter-frame stretching, tearing at the clamps Erequently destroys the web. In the case of non-woven webs made from short length staple fibers, individual fibers become separated because the stretching tension exceeds the bonding strength of the bonded cross-over points of the fibers.
Objects of the Invention ', It is an object of the present invention to provide a novel process and apparatus for stretching a non-~oven web of synthetic material.
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Another object of the present Lnventlon is to provide a noveL process and apparatus Eor bi-axlally stretching a non-woven web of synthetic material to substantially improve optimum strength.
Various other objects and advantages of the present invention will become apparent from the following detailed description of an exemplary embodiment thereof ~ith the novel features thereof being particularly pointed out Ln the appended claims.
Summary of the Invention In accordance with the present invention, there is provided a process and apparatus for selective stretching a non-woven web of synthetic fibers in a station provided with a set of grooved rolls. The groove pattern of the rolls is general~
ly a sinosoidal wave having a distance between grooves of less than 1.0 millimeters times the web basis weight in gr~ms per square meter. Accordîngly, the web of synthetic material is stretched in a manner to affect uniform stretching betw-een - the bonding points of each individual fiber thereby producing a web of larger dimension in the direction of stretch~ -In accordance with a preferred embodiment of the present invention, there is provided a process and apparatus for bi-axially stretching such a web of synthetic fiber in a first and second station ~herein the first and second stations are provided with sets of rolls having grooves parallel and per-pendicular, respectively, to the axis of each set of rolls.
The groove pattern of each set of rolls is such that the distance between grooves is less than 1.0 millimeters times the web basis weight in grams per square meter. .The non-woven web of synthetic material is stretched in a manner to affect uniform i , 1~7~87~
stretching between bonding points o~ each incliviclual f:Lber there-by producing a web o~ bi-axlally larger dImension and corres-pondingly reduced base we:Lght.
~rief Description of the Drawings The invention will be more clearly understood by reference to the following detailed description of an exemplary embodiment thereof in conjunction with the accompanying drawings wherein, Figure 1 is a schematic side elevational view of the first station of the apparatus and process of the present invention;
Figure 2 is an isometric view oE one of the rollers of the first station;
Figure 3 graphically illustra-tes a sinosoidal curve;
Figure 4 is a schematic side elevational view of the second station; and Figure 5 is a top view of the second station.
Detailed Description of the Invention Drive and support assemblies, timing and fiafety circuits and the like known and used by those skilled in the art have been omitted in the interest of clarity.
~ eferring to Figure 1 illustrating the first station of the process and apparatus oE the present invention, there is provided a supply roll 10 on which is mounted a non-woven web 12 of orientable polymeric fibers (continuous or discontinuous), The web 12 is coursed between a nip 14 of a pair of rollers 16 having a pluraiity of grooves 18 parallel to the axis of the rollers 16; as seen in Figure 2. The web 12 is maintained against the lower grooved roller 14 by a pair of press rollers 21 to ensure that the velocity ( ~) of the web 12 is substantially identical to the surface velocity ( ~) of the grooved rollerfi 16.
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The grooves 13 of the roll.ers 16 are intermeshed like gears, a~
known to those skilled in the art. As the web 12 enters the nip 14, the web 12 assumes the shape of a groove 18 and is stretched by a factor determined by the length of the sinus wave " ~ See Figure 3) of the groove divided b~ the original length of the web "~" between contact points of each respective groove tip, since the web is prevented from slipping by the press rollers 21to prevent the i.ntroduction of more material 7 as is more commonly practiced in the corrugating art.
The draw ratio~ )is calculated by the following equation where a= ~d/2 ~J , and the sinus wave of the groove is /~= J ¦l+a cos2x dx - ~
Thus for d/~ratios of 1.0, 0.75 and 0.5 the draw ratios are 2.35, ~:
Background of the Invention Many non-woven and (continuous filament) spun-bonded fabrics or webs have found use in the market as substitutes for textile materials. Such webs consist of randomly laid fibers, either in the form of short staple lengths or continuous fila-ments, which are undrawn or only partially drawn, and have there~
fore not obtained their optimum strength. Conventional methods of web stretching, such as Goudet-roll stretching and lateral stretching in tenter-frames, do not lend themselves to stretching of such webs. In longitudinal roll stretching a narrowing of the web occurs, the individual fibers between bcnding points do not undergo molecular orientation. In lateral tenter-frame stretching, tearing at the clamps Erequently destroys the web. In the case of non-woven webs made from short length staple fibers, individual fibers become separated because the stretching tension exceeds the bonding strength of the bonded cross-over points of the fibers.
Objects of the Invention ', It is an object of the present invention to provide a novel process and apparatus for stretching a non-~oven web of synthetic material.
:' .' .
.; ~ .
. ~ .' . .
. .
Another object of the present Lnventlon is to provide a noveL process and apparatus Eor bi-axlally stretching a non-woven web of synthetic material to substantially improve optimum strength.
Various other objects and advantages of the present invention will become apparent from the following detailed description of an exemplary embodiment thereof ~ith the novel features thereof being particularly pointed out Ln the appended claims.
Summary of the Invention In accordance with the present invention, there is provided a process and apparatus for selective stretching a non-woven web of synthetic fibers in a station provided with a set of grooved rolls. The groove pattern of the rolls is general~
ly a sinosoidal wave having a distance between grooves of less than 1.0 millimeters times the web basis weight in gr~ms per square meter. Accordîngly, the web of synthetic material is stretched in a manner to affect uniform stretching betw-een - the bonding points of each individual fiber thereby producing a web of larger dimension in the direction of stretch~ -In accordance with a preferred embodiment of the present invention, there is provided a process and apparatus for bi-axially stretching such a web of synthetic fiber in a first and second station ~herein the first and second stations are provided with sets of rolls having grooves parallel and per-pendicular, respectively, to the axis of each set of rolls.
The groove pattern of each set of rolls is such that the distance between grooves is less than 1.0 millimeters times the web basis weight in grams per square meter. .The non-woven web of synthetic material is stretched in a manner to affect uniform i , 1~7~87~
stretching between bonding points o~ each incliviclual f:Lber there-by producing a web o~ bi-axlally larger dImension and corres-pondingly reduced base we:Lght.
~rief Description of the Drawings The invention will be more clearly understood by reference to the following detailed description of an exemplary embodiment thereof in conjunction with the accompanying drawings wherein, Figure 1 is a schematic side elevational view of the first station of the apparatus and process of the present invention;
Figure 2 is an isometric view oE one of the rollers of the first station;
Figure 3 graphically illustra-tes a sinosoidal curve;
Figure 4 is a schematic side elevational view of the second station; and Figure 5 is a top view of the second station.
Detailed Description of the Invention Drive and support assemblies, timing and fiafety circuits and the like known and used by those skilled in the art have been omitted in the interest of clarity.
~ eferring to Figure 1 illustrating the first station of the process and apparatus oE the present invention, there is provided a supply roll 10 on which is mounted a non-woven web 12 of orientable polymeric fibers (continuous or discontinuous), The web 12 is coursed between a nip 14 of a pair of rollers 16 having a pluraiity of grooves 18 parallel to the axis of the rollers 16; as seen in Figure 2. The web 12 is maintained against the lower grooved roller 14 by a pair of press rollers 21 to ensure that the velocity ( ~) of the web 12 is substantially identical to the surface velocity ( ~) of the grooved rollerfi 16.
87~
The grooves 13 of the roll.ers 16 are intermeshed like gears, a~
known to those skilled in the art. As the web 12 enters the nip 14, the web 12 assumes the shape of a groove 18 and is stretched by a factor determined by the length of the sinus wave " ~ See Figure 3) of the groove divided b~ the original length of the web "~" between contact points of each respective groove tip, since the web is prevented from slipping by the press rollers 21to prevent the i.ntroduction of more material 7 as is more commonly practiced in the corrugating art.
The draw ratio~ )is calculated by the following equation where a= ~d/2 ~J , and the sinus wave of the groove is /~= J ¦l+a cos2x dx - ~
Thus for d/~ratios of 1.0, 0.75 and 0.5 the draw ratios are 2.35, ~:
2.0 and 1.6, respectively. ~ :
The web 12 after passage through the nip 14 of the rollers 16 is pulled away by a pair of tension rollers 22 having .
a surrace velocity ( ~ ) greater than the surface velocity of : :
: 20 the rollers 16, but not greater than a factor of th.e draw ratio .:
affected in the nip 14 of the rollers 16.
In accordance with the present invention, the length of the fabric is therefore increased by this factor, It is noted .~ that the web does not undergo narrowing while being longitudinally stretched or extended, as is the case with conventional roller systems. It is apparent to one skilled in the art that the web may sequentially pass through a plurality of pairs of grooved rollers 16 to further stretch lengthwise the web 12.
If stretching is permitted to be carried out beyond the residual elongation of the individual fibers, the fibers will break and ehe web lose tensile stlength. Strength per ' 1(~751~70 fabric basis weight is increased considerably up to the point of breaking fLbers. The maximum permissible draw ratio can easily be determined by measuring the residual elongation oE the individual fibers of the original web. For best results, the grooves 18 of the rollers 16 shou]d be as fine as possible, with groove distance being increased, if heavy basis weight factors are to be orientated. From experience, good results are obtained, if the distance between grooves (in mm) is less than 1.0 times the fabric basis weight (in gramlm ). The larger the groove distance, the more fiber cross~over points are being separated or broken thereby weakening the fabric structure. In the case of non-woven webs made from short stapel fibers, groove distance (d) should be one-half of the fiber length or less.
If the groove distance (d) is larger, fibers are separated out by breaking rather than stretched between the grooves, and the web thereby becomes very weak.
Referring now to Figure 4, the longitudinally stretched web 20 from the first station including press rollers 21 is introduced into a nip 24 formed by a pair of rollers 26 having a plurality of grooves 28 parallel to the circumference of the rollers 26 in a second station of the apparatus. The web 20 is caused to be coursed into the nip 24 by a pair of press rollers 30 which holds the web 20 against the lower roller 26 :~ to thereby prevent the web 20 from narrowing prior to introduction.
Once in the nip 24, the web 20 assumes the shape of the groove pattern and becomes stretched by a factor of the draw ratio determined in a manner similar to the dra~ ratio discussed w~th reference to Figure 1. In the second station, ie., lateral stretching, the web 32 is wound up at about the same velocity as the feed velocity. The crimp pattern is flattened out by stretch-ing the web 32 laterally by means of tenter clamps or curved ~7~870 ~lount ~lope rolls, generaLly lndicated as 34 such as known and used by one skilled in the art wlth the product belng collected on a roller 36. For best results, the longltudlnal and lateral stretchlng steps are repeated alternately through multiple passes each havlng a relatlvely low draw ratlo, until the total permlsslble draw ratio ls reached. The number of longitudinal and lateral passes, as well as the extent of the stepwise draw ratios, can be chosen so that a final fabric is obtained with uniEorm properties balanced in both directions.
With the process and apparatus oE the present invention, non-woven and spun-bonded webs and fabrics can be produced having a much higher tensile tear strength (expressed as grams per centimeter) and tensile tear length (expressed as meters) per basis weight than unstretched fabrics. The fabric basis weight is decreased during the stretching process by a factor of the area draw ratio ( = longitudinal draw ratio x lateral draw ratio). The denier of the individual fibers is reduced similarly, resulting in a web of still bonded but finer fibers. Fabrics processed by the present invention are softer and drapier than the original material and result in completely new types of products.
Examples of the Invention Operation of the process and apparatus is described in the following examples which are intended to be merely illustra- ;
tive and the invention is not to be regarded as limited thereto.
Example I ~ ~-A randomly laid web of partially oriented polypropylene ; fibers (cross-over points of the filaments being most fused during melt blowing step of web formation) produced by a process similar to that described in U.S. Patent No. 3,849~241 having the following properties is processed in accordance w-ith the present .;
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'`'": ' ~5870 invention:
Basis weight : 100 gm/m Filament denier : 1 - 5 Tear strength (tensile) 785 gm/cm. (linear~
Tensile tear length: 785 meters The web is introduced into rollers 16 having a surface velocity of 3.05 meters per minute. Each groove is formed with a depth (d) of 3mm and with a spacing (~ ) of 4mm thereby resulting in a draw ratio of 2Ø The web 20 is pulled from the nip 14 by tension rollers 22 having a surface velocity of 6.10m. per minute.
The web is subsequently passed through similar longitudinal and lateral stretch stations until a total draw ratio of 16.0 is reached at which point the web exhibited the following properties:
Basis weight : 6.2 gm/m Filament denier : 0.1 - 1 Tear strength (tensile) 98.4gm/cm (linear) Tensile tear length : 1587 meters The tensile tear length per basis weight (expressed as meters) of the product is 1587 as compared with that of 785 of the starting polypropylene fibrous material.
Example II
A commercially available spun-bonded web of con-tinuously polyester fiber having the following properties is processed in grooved rollers having a depth of 2.5 mm and a width of 5.0mm (draw ratio is 1.6):
Basis ~eight : 63 gm/m Filament denier : 15 Tear strength (tensile) 1102 gm/cm (linear) Filament elongation: 250 The web is introcluced into the rollers 16 at a surface velocity of ,, .
~L~75~
The web 12 after passage through the nip 14 of the rollers 16 is pulled away by a pair of tension rollers 22 having .
a surrace velocity ( ~ ) greater than the surface velocity of : :
: 20 the rollers 16, but not greater than a factor of th.e draw ratio .:
affected in the nip 14 of the rollers 16.
In accordance with the present invention, the length of the fabric is therefore increased by this factor, It is noted .~ that the web does not undergo narrowing while being longitudinally stretched or extended, as is the case with conventional roller systems. It is apparent to one skilled in the art that the web may sequentially pass through a plurality of pairs of grooved rollers 16 to further stretch lengthwise the web 12.
If stretching is permitted to be carried out beyond the residual elongation of the individual fibers, the fibers will break and ehe web lose tensile stlength. Strength per ' 1(~751~70 fabric basis weight is increased considerably up to the point of breaking fLbers. The maximum permissible draw ratio can easily be determined by measuring the residual elongation oE the individual fibers of the original web. For best results, the grooves 18 of the rollers 16 shou]d be as fine as possible, with groove distance being increased, if heavy basis weight factors are to be orientated. From experience, good results are obtained, if the distance between grooves (in mm) is less than 1.0 times the fabric basis weight (in gramlm ). The larger the groove distance, the more fiber cross~over points are being separated or broken thereby weakening the fabric structure. In the case of non-woven webs made from short stapel fibers, groove distance (d) should be one-half of the fiber length or less.
If the groove distance (d) is larger, fibers are separated out by breaking rather than stretched between the grooves, and the web thereby becomes very weak.
Referring now to Figure 4, the longitudinally stretched web 20 from the first station including press rollers 21 is introduced into a nip 24 formed by a pair of rollers 26 having a plurality of grooves 28 parallel to the circumference of the rollers 26 in a second station of the apparatus. The web 20 is caused to be coursed into the nip 24 by a pair of press rollers 30 which holds the web 20 against the lower roller 26 :~ to thereby prevent the web 20 from narrowing prior to introduction.
Once in the nip 24, the web 20 assumes the shape of the groove pattern and becomes stretched by a factor of the draw ratio determined in a manner similar to the dra~ ratio discussed w~th reference to Figure 1. In the second station, ie., lateral stretching, the web 32 is wound up at about the same velocity as the feed velocity. The crimp pattern is flattened out by stretch-ing the web 32 laterally by means of tenter clamps or curved ~7~870 ~lount ~lope rolls, generaLly lndicated as 34 such as known and used by one skilled in the art wlth the product belng collected on a roller 36. For best results, the longltudlnal and lateral stretchlng steps are repeated alternately through multiple passes each havlng a relatlvely low draw ratlo, until the total permlsslble draw ratio ls reached. The number of longitudinal and lateral passes, as well as the extent of the stepwise draw ratios, can be chosen so that a final fabric is obtained with uniEorm properties balanced in both directions.
With the process and apparatus oE the present invention, non-woven and spun-bonded webs and fabrics can be produced having a much higher tensile tear strength (expressed as grams per centimeter) and tensile tear length (expressed as meters) per basis weight than unstretched fabrics. The fabric basis weight is decreased during the stretching process by a factor of the area draw ratio ( = longitudinal draw ratio x lateral draw ratio). The denier of the individual fibers is reduced similarly, resulting in a web of still bonded but finer fibers. Fabrics processed by the present invention are softer and drapier than the original material and result in completely new types of products.
Examples of the Invention Operation of the process and apparatus is described in the following examples which are intended to be merely illustra- ;
tive and the invention is not to be regarded as limited thereto.
Example I ~ ~-A randomly laid web of partially oriented polypropylene ; fibers (cross-over points of the filaments being most fused during melt blowing step of web formation) produced by a process similar to that described in U.S. Patent No. 3,849~241 having the following properties is processed in accordance w-ith the present .;
:, :
; ::
i ~ .
'`'": ' ~5870 invention:
Basis weight : 100 gm/m Filament denier : 1 - 5 Tear strength (tensile) 785 gm/cm. (linear~
Tensile tear length: 785 meters The web is introduced into rollers 16 having a surface velocity of 3.05 meters per minute. Each groove is formed with a depth (d) of 3mm and with a spacing (~ ) of 4mm thereby resulting in a draw ratio of 2Ø The web 20 is pulled from the nip 14 by tension rollers 22 having a surface velocity of 6.10m. per minute.
The web is subsequently passed through similar longitudinal and lateral stretch stations until a total draw ratio of 16.0 is reached at which point the web exhibited the following properties:
Basis weight : 6.2 gm/m Filament denier : 0.1 - 1 Tear strength (tensile) 98.4gm/cm (linear) Tensile tear length : 1587 meters The tensile tear length per basis weight (expressed as meters) of the product is 1587 as compared with that of 785 of the starting polypropylene fibrous material.
Example II
A commercially available spun-bonded web of con-tinuously polyester fiber having the following properties is processed in grooved rollers having a depth of 2.5 mm and a width of 5.0mm (draw ratio is 1.6):
Basis ~eight : 63 gm/m Filament denier : 15 Tear strength (tensile) 1102 gm/cm (linear) Filament elongation: 250 The web is introcluced into the rollers 16 at a surface velocity of ,, .
~L~75~
3.05 meters per minute and is withdrawn by tenslon rollers 22 at a velocity of ~l.88 meters per mLnute. AEter passage through two complete stretchings operations (both including longitudinal and lateral stations), the web exhibited the followlng properties:
Basis weight : 25 gmlm Filament denier : 6 Tear strength (tensile) 787~4 gm/cm Tensile tear length (meter) of the product is 3149.6 meters as compared to 1749.2 of the starting polyester material.
Example III
A latex bonded randomly laid non-woven web consist-ing of 1.27 cm polyester staple fibers having the following properties is processed in accordance with the present invention:
Basis weight : 32 gm/m Filament denier : 7 Tear strength(tensile) 157.5 gm/cm(linear) The respective rollers were formed with grooves having a depth of lmm and a width of 3mm (draw ratio 1.8). The web after bi-axially stretching followed by pressing between calendar rolls exhibited the following properties:
Basis weight : 18 gm/m Filament denier : 4.0 Tear strength : 177.2gm/cm(linear) The tensile tear length (meter) of the product i5 984.4 as compared with 492.2 of the starting material.
While the present invention has been described with reference to the passage of a web through a first longitudinal stretching station and thence a lateral stretching station, it is apparent that such stations may be altered with the web being first introduced into a lateral stretching station. Further, the apparatus and process of the present invention ~ay be :
10~7587~
arranged to provide Eor :Longitudinal stretching to the limlt oE the material capab:Llities prior to lateral stretchLng. Addit ionally, it :is contemplated that in some instances that it is desirable to stretch the material solely in elther a longitudinal or lateral direction.
While the invent:Lon has been described in connection with an exemplary embodiment thereof, it will be understood that many modifications will be apparent to those of ordinary skill in the art and that this application is intended to cover any adaptations or variations thereoE. Therefore, it is manifestly intended that this invention be only limited by the claims and ehe equlvalents thereof.
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Basis weight : 25 gmlm Filament denier : 6 Tear strength (tensile) 787~4 gm/cm Tensile tear length (meter) of the product is 3149.6 meters as compared to 1749.2 of the starting polyester material.
Example III
A latex bonded randomly laid non-woven web consist-ing of 1.27 cm polyester staple fibers having the following properties is processed in accordance with the present invention:
Basis weight : 32 gm/m Filament denier : 7 Tear strength(tensile) 157.5 gm/cm(linear) The respective rollers were formed with grooves having a depth of lmm and a width of 3mm (draw ratio 1.8). The web after bi-axially stretching followed by pressing between calendar rolls exhibited the following properties:
Basis weight : 18 gm/m Filament denier : 4.0 Tear strength : 177.2gm/cm(linear) The tensile tear length (meter) of the product i5 984.4 as compared with 492.2 of the starting material.
While the present invention has been described with reference to the passage of a web through a first longitudinal stretching station and thence a lateral stretching station, it is apparent that such stations may be altered with the web being first introduced into a lateral stretching station. Further, the apparatus and process of the present invention ~ay be :
10~7587~
arranged to provide Eor :Longitudinal stretching to the limlt oE the material capab:Llities prior to lateral stretchLng. Addit ionally, it :is contemplated that in some instances that it is desirable to stretch the material solely in elther a longitudinal or lateral direction.
While the invent:Lon has been described in connection with an exemplary embodiment thereof, it will be understood that many modifications will be apparent to those of ordinary skill in the art and that this application is intended to cover any adaptations or variations thereoE. Therefore, it is manifestly intended that this invention be only limited by the claims and ehe equlvalents thereof.
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Claims (6)
1. A process for biaxially stretching a non-woven web of thermoplastic orientable polymeric fibers to thereby improve the strength of the web which comprises:
a) introducing said web into a nip of interdigitating rollers having grooves substantially parallel to the axis of said rollers, the distance between grooves being less than one millimeter times the web basis weight in grams per square meter;
b) controlling the velocity of introduction of said web into said nip to assume and maintain the velocity substan-tially identical to the surface velocity of said rollers to pre-vent slipping of said web and thereby longitudinally and uniformly stretch said web between bonding points of each indivi-dual fiber by a deflection of said web into the shape of said grooves;
c) withdrawing said web from said rollers at a velocity greater than the rotational velocity of said rollers;
d) introducing said web into a nip of interdigitating rollers having grooves substantially perpendicular to the axis of said rollers, the distance between grooves being less than one millimeter times the web basis weight in grams per square meter;
e) controlling the velocity of introduction of said web into the said nip to assume and maintain the velocity sub-stantially identical to the surface velocity of said rollers to prevent narrowing of said web prior to introduction into said nip and thereby to laterally and uniformly stretch said web between bonding points of each individual fiber by a deflection of said web into the shape of said grooves;
f) withdrawing said web from said rollers at a velocity substantially corresponding to the velocity of introduction; and g) collecting a biaxially stretched web,
a) introducing said web into a nip of interdigitating rollers having grooves substantially parallel to the axis of said rollers, the distance between grooves being less than one millimeter times the web basis weight in grams per square meter;
b) controlling the velocity of introduction of said web into said nip to assume and maintain the velocity substan-tially identical to the surface velocity of said rollers to pre-vent slipping of said web and thereby longitudinally and uniformly stretch said web between bonding points of each indivi-dual fiber by a deflection of said web into the shape of said grooves;
c) withdrawing said web from said rollers at a velocity greater than the rotational velocity of said rollers;
d) introducing said web into a nip of interdigitating rollers having grooves substantially perpendicular to the axis of said rollers, the distance between grooves being less than one millimeter times the web basis weight in grams per square meter;
e) controlling the velocity of introduction of said web into the said nip to assume and maintain the velocity sub-stantially identical to the surface velocity of said rollers to prevent narrowing of said web prior to introduction into said nip and thereby to laterally and uniformly stretch said web between bonding points of each individual fiber by a deflection of said web into the shape of said grooves;
f) withdrawing said web from said rollers at a velocity substantially corresponding to the velocity of introduction; and g) collecting a biaxially stretched web,
2. The process as defined in Claim 1 wherein steps (d) to (E) are effected prior to steps (a) to (c).
3. An apparatus for bi-axially stretching a non-woven web of orientable polymeric material which comprises:
a) a first station means for stretching said web in a first direction and including a first set of interdigitating rollers formed with grooves having a distance therebetween of less than one millimeter times the web basis weight in grams per square meter, said first set of interdigitating rollers stretching incremental portions of said web in a first direction;
(b) first regulator means for controllably introducing said web into said first set of interdigitating rollers;
(c) a first take-up means for elongating said web in said first direction upon withdrawal of said web from said first set of interdigitating rollers;
(d) a second station means for stretching said web in a second direction and including a second set of interdigitating rollers formed with grooves having a distance therebetween of less than one millimeter times the web basis weight in grams per square meter, said second set of interdigitating rollers stretching incremental portions of said web in a second direction;
(e) a second regulator means for controllably intro-ducing said web into said second set of interdigitating rollers;
(f) a second take-up means for elongating said web in said second direction upon withdrawal of said web from said second set of interdigitating rollers; and collecting means for receiving said web of bi-axially orientated material.
a) a first station means for stretching said web in a first direction and including a first set of interdigitating rollers formed with grooves having a distance therebetween of less than one millimeter times the web basis weight in grams per square meter, said first set of interdigitating rollers stretching incremental portions of said web in a first direction;
(b) first regulator means for controllably introducing said web into said first set of interdigitating rollers;
(c) a first take-up means for elongating said web in said first direction upon withdrawal of said web from said first set of interdigitating rollers;
(d) a second station means for stretching said web in a second direction and including a second set of interdigitating rollers formed with grooves having a distance therebetween of less than one millimeter times the web basis weight in grams per square meter, said second set of interdigitating rollers stretching incremental portions of said web in a second direction;
(e) a second regulator means for controllably intro-ducing said web into said second set of interdigitating rollers;
(f) a second take-up means for elongating said web in said second direction upon withdrawal of said web from said second set of interdigitating rollers; and collecting means for receiving said web of bi-axially orientated material.
4. The apparatus as defined in Claim 3 wherein said first and second set of interdigitating rollers are formed with grooves which are parallel and perpendicular, respectively, to said first and second set of interdigitating rollers.
5. The apparatus as defined in Claim 4 wherein said regulator means include a roller rotating at substantially the same rotational velocity as that of an associated interdigitating roller.
6. The apparatus as defined in Claim 5 wherein said first take-up means are press rollers operated at a rotational velocity proportional to the draw ratio effected in said first set of interdigitating rollers.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US56362375A | 1975-03-31 | 1975-03-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1075870A true CA1075870A (en) | 1980-04-22 |
Family
ID=24251265
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA249,031A Expired CA1075870A (en) | 1975-03-31 | 1976-03-29 | Process and apparatus for stretching a non-woven web of an orientable polymeric material |
Country Status (4)
| Country | Link |
|---|---|
| JP (2) | JPS6026859B2 (en) |
| CA (1) | CA1075870A (en) |
| DE (1) | DE2613822B2 (en) |
| GB (1) | GB1521183A (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4336638A (en) | 1975-05-23 | 1982-06-29 | Netlon Limited | Apparatus for stretching plastic webs |
| CA1123566A (en) * | 1977-02-09 | 1982-05-18 | Eckhard C.A. Schwarz | Process and apparatus for stretching a tubularly-formed sheet of a thermoplastic material and the product produced thereby |
| DE4122121C2 (en) * | 1991-07-04 | 1993-11-11 | Kuesters Eduard Maschf | Wide stretching device |
| JP2003073967A (en) * | 2001-08-31 | 2003-03-12 | Mitsui Chemicals Inc | Soft nonwoven fabric and method for producing the same |
| AR038590A1 (en) * | 2002-02-22 | 2005-01-19 | Clopay Plastic Prod Co | LAMINATED FILM SHEET AND METHODS FOR MANUFACTURING |
| JP4871046B2 (en) | 2006-07-18 | 2012-02-08 | ユニ・チャーム株式会社 | Apparatus for stretching a web formed of a thermoplastic synthetic resin |
| DE102006033998B4 (en) * | 2006-07-22 | 2008-06-26 | Krones Ag | Machine for packaging objects |
| JP4757139B2 (en) * | 2006-08-09 | 2011-08-24 | 花王株式会社 | Sheet manufacturing method and processing apparatus |
| JP4799343B2 (en) * | 2006-09-25 | 2011-10-26 | 花王株式会社 | Sheet manufacturing method and processing apparatus |
| WO2016172357A1 (en) * | 2015-04-21 | 2016-10-27 | First Quality Baby Products, Llc | Manufacturing process for elastomeric laminate |
| CN110670284A (en) * | 2019-10-29 | 2020-01-10 | 上海仪耐新材料科技有限公司 | Mesh stretching and shaping device and method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5029523B2 (en) * | 1971-11-16 | 1975-09-23 | ||
| JPS4936054A (en) * | 1972-08-09 | 1974-04-03 | ||
| JPS4948577A (en) * | 1972-09-12 | 1974-05-10 |
-
1976
- 1976-03-29 CA CA249,031A patent/CA1075870A/en not_active Expired
- 1976-03-29 GB GB1252176A patent/GB1521183A/en not_active Expired
- 1976-03-31 DE DE19762613822 patent/DE2613822B2/en not_active Ceased
- 1976-03-31 JP JP51036685A patent/JPS6026859B2/en not_active Expired
-
1979
- 1979-03-14 JP JP2880779A patent/JPS5567052A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| DE2613822A1 (en) | 1976-10-14 |
| JPS5567052A (en) | 1980-05-20 |
| JPS51123364A (en) | 1976-10-28 |
| GB1521183A (en) | 1978-08-16 |
| DE2613822B2 (en) | 1980-09-11 |
| JPS6026859B2 (en) | 1985-06-26 |
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| MKEX | Expiry |