CA1125973A - Method and apparatus for producing perforated film - Google Patents
Method and apparatus for producing perforated filmInfo
- Publication number
- CA1125973A CA1125973A CA328,166A CA328166A CA1125973A CA 1125973 A CA1125973 A CA 1125973A CA 328166 A CA328166 A CA 328166A CA 1125973 A CA1125973 A CA 1125973A
- Authority
- CA
- Canada
- Prior art keywords
- sheet
- molding element
- length
- major axis
- minor axis
- 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
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
- A61F13/00—Bandages or dressings; Absorbent pads
- A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
- A61F13/15577—Apparatus or processes for manufacturing
- A61F13/15707—Mechanical treatment, e.g. notching, twisting, compressing, shaping
- A61F13/15731—Treating webs, e.g. for giving them a fibrelike appearance, e.g. by embossing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
- B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
- B26F1/26—Perforating by non-mechanical means, e.g. by fluid jet
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/18—Thermoforming apparatus
- B29C51/20—Thermoforming apparatus having movable moulds or mould parts
- B29C51/22—Thermoforming apparatus having movable moulds or mould parts rotatable about an axis
- B29C51/225—Thermoforming apparatus having movable moulds or mould parts rotatable about an axis mounted on a vacuum drum
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/10—Forming by pressure difference, e.g. vacuum
Abstract
Case V-4438 ABSTRACT
METHOD AND APPARATUS FOR PRODUCING PERFORATED FILM
An improved process and apparatus for generating a thermoplastic film of a type suitable for use in disposable garments such as diapers. The method comprises disposing an impervious film of thermoplastic material at an elevated temperature on a rotating molding-perforating surface element, which has regularly arranged, generally contiguous hexagonal depressions terminating in elliptical holes, applying a fluid pressure to the film to cause flow into the depressions and rupture at said elliptical holes.
The elliptical holes are oriented with the major axes in the direction of movement of the rotating surface.
METHOD AND APPARATUS FOR PRODUCING PERFORATED FILM
An improved process and apparatus for generating a thermoplastic film of a type suitable for use in disposable garments such as diapers. The method comprises disposing an impervious film of thermoplastic material at an elevated temperature on a rotating molding-perforating surface element, which has regularly arranged, generally contiguous hexagonal depressions terminating in elliptical holes, applying a fluid pressure to the film to cause flow into the depressions and rupture at said elliptical holes.
The elliptical holes are oriented with the major axes in the direction of movement of the rotating surface.
Description
5~3 l Case V-4438 METHOD AND APPARATUS FOR PRODUCING PERFORATED FILM :-The present invention relates to thermoplastic sheet products and to a method and apparatus for their manufacture.
More particularly, the invention is related to a method and apparatus for perforating a continuous shee~ or film of ~hermoplastic material to produce film having increased strength and reduced edge curl.
Perforated thermoplastic sheets have many use~ul applications. Perforated sheets are used in gardening and farming to prevent the growth of grass and other weeds while permittin~ more moisture to be transmit~ed through the shee~
to the soil beneath the sheet. Perforated sheets are also used for making disposable baby diapers. Koæak, in U. S.
. Patent No. 3,814,lOl discloses diapers employing perforated thermoplastic sheets which permit the low of liquid in the direction of the absorbent material in the diaper but sub-stantially reduce the possibility of flow in the opposite direction, In the Kozak structure the film has a series of inwardly directed "dimples", and the apertures provided are a series of short slits in the film.
In Thompson - U. S. Patent No. 3,929,135 a baby diaper conskruction is shown, which includes a perorated outer film of thermoplastic material. In the Thompson dlsclosure the perforations are in the form of tapered capillaries with an angle of taper about 10 to about 60, a base opening of from about 0.006 to about 0.25 mil (.15 to 6.3 mm) and an apex opening of about 0.004 to about O.lO0 inch (O.l to 2.5 mm) said inwardly projecting capillary apices being in con-tact with absorbent material.
. .... ..
~ ~ .
- . . ; :
~ZS~'~3 While the films an~ composite article of the prior ar~
appear to be entirely Eunctional, certain weaknesses have been observed which are met by the process of the present invention.
In particular, an improved -tactile attri~ute or "hand" was needed on the face side, that is, the final film side opposite the side from which the perforated capillaries project. Moreover, a more attractive visual appearance was desired. In addition, it was desired to avoid a problem of edge curl encountered in prior film webs.
The present invention does provide improvement in these respects. It comprises placing a performed film of thermoplastic material at an elevated temperature against a continually rotating moving element, having depressions and apertures of a particular character and applying a fluid pressure differential to said film to cause flow into said depressions and rupture at the apertures. The depressions are a series o~ generally adjacently spaced hexagonal depressions terminating in elliptical holes oriented with the major axis parallel to the direction of rotation of the molding element.
The above method may be carried out hy way of an apparatus for the manufacture of thermoplastic sheet having elliptical holes comprising: a. a rotatable molding element means for receiving thermoplastic sheet, the molding element means having a series of hexagonal-shaped depressions having centered therein elliptical hole means, the elliptical hole means having a major axis and a minor axis, the major axis being oriented parallel to the direction in which the molding element means is being rotated; b. means for applying a fluid pressure d:ifferential to the surface of the ther~oplastic sheet to force sd/~ -2-, , .
:', . . ' ' the sheet against the molding element means to effect rupturing of the sheet and the formation of elliptical hole means in the sheet; and, c. means for rotating the molding element means.
Furthermore the present invention con-temp]ates a per-forated molding element for the manufacture o~ thermoplastic sheet having elliptical holes comprising a rotatable screen means for receiving thermoplastic sheet to be perforated, the screen means having a series of hexagonal-shaped depressions having centered therein elliptical hole means, the hole means having a major axis and a minor a~is, the major axis being oriented parallel to the direction in which the screen means is rotatable.
The details of the process and apparatus of the invention is given in the urther description below in conjunction with the figures, which include:
FIGURE 1, a perspective, partially cut-away schematic - view of a portion of the apparatus employed in the present invention;
FIGURE 2, an enlarged, partially cut-away section of Figure 1;
FIGURE 3, an enlarged, plan view of the moldiny element of Figures 1 and 2;
FIGURE 4, a cross-sectional view taken along lines 4-4 of Figure 3; and 5~73 FIGURE 5, a cu~-away, enlarged vi.ew of one of the ellipti-cal hGles shown in Figure 3.
- Referring now to Figure 1, a stationary cylindrical drum 10 is shown supported by a cen~rally disposed support or axle 12. The outer cylin~rical surface 13 of drum 10 is preferably formed of highly polished metal ~ut may be made of any other material having a relatively low coefficient : of friction. A molding element or screen 16, having edge ~ 16a, is mounted around surface 13 of drum 10 and is adapted ; 10 to be rotated ~reely thereon. ~olding element 16 may be formed as an integral unit in the shape of a cylinder and adapted to be slipped on drum 10 from an end thereof or it may be wrapped round drum lO and then secured in any suit-able manner. Thus, axle 12 ~orms the cPnterline about which molding element 16 rotates. For the purpose of rotating element 16, a gear drive may be employed which is adapted to mesh with gearing provided on the element itself, or a pulley drive may be connected to the molding element by means o~ caps provided on the ends thereof. I~ desired, element 16 could be rigidly attached to drum 10 and the entire drum could be rotated, thereby rotating element 16.
To form the film perforated in accordance with the present invention, it is necessary that the molding element pattern depicted in Figure 3 be employed. The molding element pattern of Figures 3 thru 5 can be seen to be a series of generally hexagonal-shaped depressions 17 attached at L'~ir edges. The hexagonal depressions have elliptical-shaped holes 18 centered therein and sloping sidewalls 17a as seen in Figure 4. The holes 18 are elliptical in shape and oriented so that the major axis "Y" is parallel to the direction of rotation of the molding element, the direction of rotation being indicated by the arrows "D" in Figures 1 thru 3, and 5. The minor axis "X" of the ellipse is oriented in a direction perpendicular to the direction of rotation of the molding element. Although the elliptical holes may be varied for particular types of film, the preferred ellip-tical hole 18 has a major axis "Y" with a length of from 5~373 about 24 mils to about 26 m;ls (about 0.6 to 0.66 rm~) and a minor axis "X" with a length o~ fLom about l7 mlls to about ]9 miis (about 0.43 to 0.49 mm~; most preferably, maJor axis "Y" has a length oX 25 mils (about .63 mm) and minor axis "X" has a length of 18 mils (abou~ .45 m~
To effect per~oration of the thermoplastic sheet 14, a fluid pressure differential is applied to the surface of sheet 14 to cause the thermoplastic sheet 14 to flow into the hexagonal depressions 17 and onward th~ough elliptical holes 18 to thereby rupture and form Plliptical holes in the film. The pressure differential may be cre-ated by employing a vacuum chamber 20 in drum 10 on the underside of molding elmeent 16 by any means well-known in the art. An example of a typical chamber is shown in U. S. Pat~nt No. 3,054,148, to which re~erence is made.
The vacuum cha~ber 20 is schematically represented in Figures 1 and 2 by dotted lines.
- The thermoplastic shee~ 14 may be heated prior to -contacting molding element 16 if desired or if necessary to effect rup~ure, and molding element 16 may be heated to further soften the film if desired. Furthermore, conven- ~;
tional cooling means may be used to cool film 14 after the film has been perforated.
Any flexible thermoplastic material which may be formed into flexible film or sheets may be used in the ~roductlon of the novel products of the present invention.
Exemplary thermoplastic materials include cellulose ester, e.g., cellulose acetate, cellulose propionate, cellulose butyrate; mixed esters of cellulose; cellulose ethers, e.g., ethyl cellulose; nylon and polymeric materials, e.g., polyvinyl alcohol, polyvinyl alcohol acetals, polyvinyl choloride, polyvinyl chloride acetate, polystyral, methyl methacrylate, polyethylene, polypropylene, and other poly-olefins which may be formed into flexible sheet or film, ;35 and the like. Sheets made rom such materials may be plasticized with suitable plasticizers depending on the physical characteristics of the material employed.
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The perforated molding element 16 may be made of metal or any other suitable materi.al. The molc~ing elernent may be made from a metal sheet ha.ving t;he perforatéd design stamped or otherwise Cllt from the sheet. Furthermore, ;
S the perforation of the sheets may be provided by etching a plate that makes an elllptical hoIe.
:, ~:
, . ~ ' .~
.
.
, . : . ,. .
, ~
: .:. :. . . :
, , ~ ,. : .
,
More particularly, the invention is related to a method and apparatus for perforating a continuous shee~ or film of ~hermoplastic material to produce film having increased strength and reduced edge curl.
Perforated thermoplastic sheets have many use~ul applications. Perforated sheets are used in gardening and farming to prevent the growth of grass and other weeds while permittin~ more moisture to be transmit~ed through the shee~
to the soil beneath the sheet. Perforated sheets are also used for making disposable baby diapers. Koæak, in U. S.
. Patent No. 3,814,lOl discloses diapers employing perforated thermoplastic sheets which permit the low of liquid in the direction of the absorbent material in the diaper but sub-stantially reduce the possibility of flow in the opposite direction, In the Kozak structure the film has a series of inwardly directed "dimples", and the apertures provided are a series of short slits in the film.
In Thompson - U. S. Patent No. 3,929,135 a baby diaper conskruction is shown, which includes a perorated outer film of thermoplastic material. In the Thompson dlsclosure the perforations are in the form of tapered capillaries with an angle of taper about 10 to about 60, a base opening of from about 0.006 to about 0.25 mil (.15 to 6.3 mm) and an apex opening of about 0.004 to about O.lO0 inch (O.l to 2.5 mm) said inwardly projecting capillary apices being in con-tact with absorbent material.
. .... ..
~ ~ .
- . . ; :
~ZS~'~3 While the films an~ composite article of the prior ar~
appear to be entirely Eunctional, certain weaknesses have been observed which are met by the process of the present invention.
In particular, an improved -tactile attri~ute or "hand" was needed on the face side, that is, the final film side opposite the side from which the perforated capillaries project. Moreover, a more attractive visual appearance was desired. In addition, it was desired to avoid a problem of edge curl encountered in prior film webs.
The present invention does provide improvement in these respects. It comprises placing a performed film of thermoplastic material at an elevated temperature against a continually rotating moving element, having depressions and apertures of a particular character and applying a fluid pressure differential to said film to cause flow into said depressions and rupture at the apertures. The depressions are a series o~ generally adjacently spaced hexagonal depressions terminating in elliptical holes oriented with the major axis parallel to the direction of rotation of the molding element.
The above method may be carried out hy way of an apparatus for the manufacture of thermoplastic sheet having elliptical holes comprising: a. a rotatable molding element means for receiving thermoplastic sheet, the molding element means having a series of hexagonal-shaped depressions having centered therein elliptical hole means, the elliptical hole means having a major axis and a minor axis, the major axis being oriented parallel to the direction in which the molding element means is being rotated; b. means for applying a fluid pressure d:ifferential to the surface of the ther~oplastic sheet to force sd/~ -2-, , .
:', . . ' ' the sheet against the molding element means to effect rupturing of the sheet and the formation of elliptical hole means in the sheet; and, c. means for rotating the molding element means.
Furthermore the present invention con-temp]ates a per-forated molding element for the manufacture o~ thermoplastic sheet having elliptical holes comprising a rotatable screen means for receiving thermoplastic sheet to be perforated, the screen means having a series of hexagonal-shaped depressions having centered therein elliptical hole means, the hole means having a major axis and a minor a~is, the major axis being oriented parallel to the direction in which the screen means is rotatable.
The details of the process and apparatus of the invention is given in the urther description below in conjunction with the figures, which include:
FIGURE 1, a perspective, partially cut-away schematic - view of a portion of the apparatus employed in the present invention;
FIGURE 2, an enlarged, partially cut-away section of Figure 1;
FIGURE 3, an enlarged, plan view of the moldiny element of Figures 1 and 2;
FIGURE 4, a cross-sectional view taken along lines 4-4 of Figure 3; and 5~73 FIGURE 5, a cu~-away, enlarged vi.ew of one of the ellipti-cal hGles shown in Figure 3.
- Referring now to Figure 1, a stationary cylindrical drum 10 is shown supported by a cen~rally disposed support or axle 12. The outer cylin~rical surface 13 of drum 10 is preferably formed of highly polished metal ~ut may be made of any other material having a relatively low coefficient : of friction. A molding element or screen 16, having edge ~ 16a, is mounted around surface 13 of drum 10 and is adapted ; 10 to be rotated ~reely thereon. ~olding element 16 may be formed as an integral unit in the shape of a cylinder and adapted to be slipped on drum 10 from an end thereof or it may be wrapped round drum lO and then secured in any suit-able manner. Thus, axle 12 ~orms the cPnterline about which molding element 16 rotates. For the purpose of rotating element 16, a gear drive may be employed which is adapted to mesh with gearing provided on the element itself, or a pulley drive may be connected to the molding element by means o~ caps provided on the ends thereof. I~ desired, element 16 could be rigidly attached to drum 10 and the entire drum could be rotated, thereby rotating element 16.
To form the film perforated in accordance with the present invention, it is necessary that the molding element pattern depicted in Figure 3 be employed. The molding element pattern of Figures 3 thru 5 can be seen to be a series of generally hexagonal-shaped depressions 17 attached at L'~ir edges. The hexagonal depressions have elliptical-shaped holes 18 centered therein and sloping sidewalls 17a as seen in Figure 4. The holes 18 are elliptical in shape and oriented so that the major axis "Y" is parallel to the direction of rotation of the molding element, the direction of rotation being indicated by the arrows "D" in Figures 1 thru 3, and 5. The minor axis "X" of the ellipse is oriented in a direction perpendicular to the direction of rotation of the molding element. Although the elliptical holes may be varied for particular types of film, the preferred ellip-tical hole 18 has a major axis "Y" with a length of from 5~373 about 24 mils to about 26 m;ls (about 0.6 to 0.66 rm~) and a minor axis "X" with a length o~ fLom about l7 mlls to about ]9 miis (about 0.43 to 0.49 mm~; most preferably, maJor axis "Y" has a length oX 25 mils (about .63 mm) and minor axis "X" has a length of 18 mils (abou~ .45 m~
To effect per~oration of the thermoplastic sheet 14, a fluid pressure differential is applied to the surface of sheet 14 to cause the thermoplastic sheet 14 to flow into the hexagonal depressions 17 and onward th~ough elliptical holes 18 to thereby rupture and form Plliptical holes in the film. The pressure differential may be cre-ated by employing a vacuum chamber 20 in drum 10 on the underside of molding elmeent 16 by any means well-known in the art. An example of a typical chamber is shown in U. S. Pat~nt No. 3,054,148, to which re~erence is made.
The vacuum cha~ber 20 is schematically represented in Figures 1 and 2 by dotted lines.
- The thermoplastic shee~ 14 may be heated prior to -contacting molding element 16 if desired or if necessary to effect rup~ure, and molding element 16 may be heated to further soften the film if desired. Furthermore, conven- ~;
tional cooling means may be used to cool film 14 after the film has been perforated.
Any flexible thermoplastic material which may be formed into flexible film or sheets may be used in the ~roductlon of the novel products of the present invention.
Exemplary thermoplastic materials include cellulose ester, e.g., cellulose acetate, cellulose propionate, cellulose butyrate; mixed esters of cellulose; cellulose ethers, e.g., ethyl cellulose; nylon and polymeric materials, e.g., polyvinyl alcohol, polyvinyl alcohol acetals, polyvinyl choloride, polyvinyl chloride acetate, polystyral, methyl methacrylate, polyethylene, polypropylene, and other poly-olefins which may be formed into flexible sheet or film, ;35 and the like. Sheets made rom such materials may be plasticized with suitable plasticizers depending on the physical characteristics of the material employed.
. ., , ! , : ., ' ., ' : ',; '. ' ' , ' '',''' ' .
' , .
L25~73 ~ 5 .~ .
The perforated molding element 16 may be made of metal or any other suitable materi.al. The molc~ing elernent may be made from a metal sheet ha.ving t;he perforatéd design stamped or otherwise Cllt from the sheet. Furthermore, ;
S the perforation of the sheets may be provided by etching a plate that makes an elllptical hoIe.
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.
.
, . : . ,. .
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: .:. :. . . :
, , ~ ,. : .
,
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the manufacture of thermoplastic sheet having elliptical perforations comprising:
a) placing a thermoplastic sheet into contact with a continuously rotating molding element means having hexagonal-shaped depressed means in which a series of elliptical hole means are centered, said hole means having a major axis and a minor axis, said major axis being oriented parallel to the direction in which said molding element means is rotating;
b) subjecting a surface of said thermoplastic sheet to the action of a fluid pressure differential to cause said sheet to flow into said elliptical hole means while maintaining said pressure differential to effect rupturing of said thermo-plastic sheet and the formation of elliptical hole means in said sheet; and, c) continuously removing the molded portions of said sheet from said molding element means.
a) placing a thermoplastic sheet into contact with a continuously rotating molding element means having hexagonal-shaped depressed means in which a series of elliptical hole means are centered, said hole means having a major axis and a minor axis, said major axis being oriented parallel to the direction in which said molding element means is rotating;
b) subjecting a surface of said thermoplastic sheet to the action of a fluid pressure differential to cause said sheet to flow into said elliptical hole means while maintaining said pressure differential to effect rupturing of said thermo-plastic sheet and the formation of elliptical hole means in said sheet; and, c) continuously removing the molded portions of said sheet from said molding element means.
2. The process of claim 1 wherein said thermoplastic sheet is heated to soften said sheet prior to said sheet coming into contact with said continuously rotating molding element means.
3. The process of claim 1 wherein said sheet means is cooled prior to removing said molded portions from said molding element means.
4. The process of claim 1 wherein said major axis has a length of from about 0.6 mm to about 0.66 mm and said minor axis has a length of from about 0.43 mm to about 0.49 mm.
5. The process of claim l wherein said major axis has a length of about 0.63 mm and said minor axis has a length of about 0.45 mm.
6. An apparatus for the manufacture of thermoplastic sheet having elliptical holes comprising:
a) a rotatable molding element means for receiving thermoplastic sheets, said molding element means having a series of hexagonal-shaped depressions having centered therein elliptical hole means, said elliptical hole means having a major axis and a minor axis, said major axis being oriented parallel to the direction in which said molding element means is being rotated;
b) means for applying a fluid pressure differential to the surface of said thermoplastic sheet to force said sheet against said molding element means to effect rupturing of said sheet and the formation of elliptical hole means in said sheet; and, c) means for rotating said molding element means.
a) a rotatable molding element means for receiving thermoplastic sheets, said molding element means having a series of hexagonal-shaped depressions having centered therein elliptical hole means, said elliptical hole means having a major axis and a minor axis, said major axis being oriented parallel to the direction in which said molding element means is being rotated;
b) means for applying a fluid pressure differential to the surface of said thermoplastic sheet to force said sheet against said molding element means to effect rupturing of said sheet and the formation of elliptical hole means in said sheet; and, c) means for rotating said molding element means.
7. The apparatus of claim 6 wherein said major axis has a length of from about 0.6 to about 0.66 mm and said minor axis has a length of from about 0.43 to about 0.49.
8. The apparatus of claim 6 wherein said major axis has a length of from about 0.63 mm and said minor axis has a length of about 0.45 mm.
9. A perforated molding element for the manufacture of thermoplastic sheet having elliptical holes comprising a rotatable screen means for receiving thermoplastic sheet to be perforated, said screen means having a series of hexagonal-shaped depressions having centered therein elliptical hole means, said hole means having a major axis and a minor axis, said major axis being oriented parallel to the direction in which said screen means is rotatable.
10. The apparatus of claim 9 wherein said major axis has a length of from about 0,6 to about 0.66 mm and said minor axis has a length of from about 0.43 to about 0,49 mm.
11. The apparatus of claim 9 wherein said major axis has a length of about 0.63 mm and said minor axis has a length of about 0.45 mm.
12. The apparatus of claim 11 wherein said molding element is formed in the shape of a cylinder and is rotatable about the centerline of said cylinder.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US90911278A | 1978-05-24 | 1978-05-24 | |
| US909,112 | 1978-05-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1125973A true CA1125973A (en) | 1982-06-22 |
Family
ID=25426652
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA328,166A Expired CA1125973A (en) | 1978-05-24 | 1979-05-23 | Method and apparatus for producing perforated film |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5519594A (en) |
| BE (1) | BE876499A (en) |
| CA (1) | CA1125973A (en) |
| DE (1) | DE2921078A1 (en) |
| FR (1) | FR2426556A1 (en) |
| GB (1) | GB2021479B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5492705A (en) | 1992-04-27 | 1996-02-20 | Dowbrands L.P. | Vegetable containing storage bag and method for storing same |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4441952A (en) * | 1981-02-02 | 1984-04-10 | The Procter & Gamble Company | Method and apparatus for uniformly debossing and aperturing a resilient plastic web |
| EP0138601B1 (en) * | 1983-10-17 | 1989-01-11 | The Procter & Gamble Company | Method and apparatus for uniformly debossing and optionally aperturing a moving plastic web |
| US4741877A (en) * | 1983-10-17 | 1988-05-03 | The Procter & Gamble Company | Uniformly debossing and aperturing a moving plastic web using stationary support member in forming area |
| US4839216A (en) * | 1984-02-16 | 1989-06-13 | The Procter & Gamble Company | Formed material produced by solid-state formation with a high-pressure liquid stream |
| SE449298B (en) * | 1984-05-15 | 1987-04-27 | Moelnlycke Ab | ABSORBING PRODUCT, SUCH AS DAMBINDE, BLOW OR WOUND |
| US4681793A (en) * | 1985-05-31 | 1987-07-21 | The Procter & Gamble Company | Non-occluding, liquid-impervious, composite backsheet for absorptive devices |
| US4591523A (en) * | 1985-05-31 | 1986-05-27 | The Procter & Gamble Company | Apertured macroscopically expanded three-dimensional polymeric web exhibiting breatheability and resistance to fluid transmission |
| US4846821A (en) * | 1987-08-24 | 1989-07-11 | The Procter & Gamble Company | Substantially fluid-impervious microbubbled polymeric web exhibiting low levels of noise when subjected to movement |
| US4778644A (en) * | 1987-08-24 | 1988-10-18 | The Procter & Gamble Company | Method and apparatus for making substantially fluid-impervious microbubbled polymeric web using high pressure liquid stream |
| US4772444A (en) * | 1987-08-24 | 1988-09-20 | The Procter & Gamble Company | Method and apparatus for making microbubbled and/or microapertured polymeric webs using hydraulic pressure |
| JP2928665B2 (en) * | 1991-08-21 | 1999-08-03 | ユニ・チャーム株式会社 | Surface sheet for absorbent article and method for producing the same |
| TW252915B (en) * | 1991-12-25 | 1995-08-01 | Kao Corp |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1591921A (en) * | 1925-03-25 | 1926-07-06 | St Annes Board Mill Co Ltd | Suction cylinder or roll of machines for making paper, paper board, mill board, and the like |
| NL114076C (en) * | 1954-06-16 | |||
| US3814101A (en) * | 1970-09-17 | 1974-06-04 | Union Carbide Corp | Disposable absorbent articles |
| US3038198A (en) * | 1956-01-03 | 1962-06-12 | Kendall & Co | Apparatus for perforating thermoplastic sheets |
| US3929135A (en) * | 1974-12-20 | 1975-12-30 | Procter & Gamble | Absorptive structure having tapered capillaries |
| JPS51109068A (en) * | 1975-03-20 | 1976-09-27 | Maruto Kasei Kogyo Kk | KAJITSUTONOYUSOYOPATSUKUO GOSEIJUSHISHIITOOMOTSUTESEIKEISURUHOHO |
-
1979
- 1979-05-23 GB GB7917936A patent/GB2021479B/en not_active Expired
- 1979-05-23 BE BE0/195353A patent/BE876499A/en not_active IP Right Cessation
- 1979-05-23 FR FR7913086A patent/FR2426556A1/en active Granted
- 1979-05-23 DE DE19792921078 patent/DE2921078A1/en not_active Ceased
- 1979-05-23 JP JP6376579A patent/JPS5519594A/en active Granted
- 1979-05-23 CA CA328,166A patent/CA1125973A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5492705A (en) | 1992-04-27 | 1996-02-20 | Dowbrands L.P. | Vegetable containing storage bag and method for storing same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5736130B2 (en) | 1982-08-02 |
| FR2426556B1 (en) | 1984-12-14 |
| DE2921078A1 (en) | 1979-12-06 |
| GB2021479B (en) | 1982-04-15 |
| FR2426556A1 (en) | 1979-12-21 |
| BE876499A (en) | 1979-11-23 |
| GB2021479A (en) | 1979-12-05 |
| JPS5519594A (en) | 1980-02-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |