US4388056A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for continuously making an air-laid fibrous web having patterned basis weight distribution
Assignee: Procter and Gamble Co
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Filing: 1982-07-06
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Granted: 1983-06-14
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Expires: 2002-07-06
Abstract
Abstract An apparatus for continuously forming a cyclically contoured and densified air-laid fibrous web having alternately spaced relatively high basis weight narrow regions and relatively low basis weight wide regions. This web can be severed by spaced transverse cuts into uniform, contoured articles such as fibrous absorbent cores for disposable diapers having relatively thick, narrow and absorbent crotch areas; and relatively thin waistband regions. The apparatus comprises means for producing such a web without stepwise basis weight gradients. In one embodiment, the apparatus comprises an air-laying drum having an endless lay down surface which is partially masked to define a plurality of alternately spaced relatively wide areas and relatively narrow areas. The apparatus further comprises air-flow modulating means which can be adjusted to provide a relatively broad range of pressure differentials across the relatively wide areas of the lay down surface while continuously maintaining a relatively fixed, high pressure differential across the relatively narrow areas of the lay down surface. Thus, the relative basis weight (weight of fibers per unit area of the web) of the wide regions of the web can be controlled through a limited range without substantially affecting the basis weight in the relatively narrow regions of the web, and without precipitating any step-wise gradients in basis weight or step-wise changes in thickness; in particular in the machine direction.
Inventors
- 👤 Franky B. Lee
- 👤 Orin Jobes, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:32
CPC Classifications
A; A61; A61F; A61F13/00; A61F13/15; A61F13/15577; A61F13/15617; A61F13/15658
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
247 words
In an improved apparatus for continuously forming an air-laid fibrous web having oppositely phased, cyclically undulating side edges and a predetermined patterned basis weight distribution which apparatus includes a laydown drum having a forming surface, means for forming and directing a column of air entrained fibers onto said forming surface and depositing fibers on said forming surface, and air flow inducing means for drawing fiber-depleted air through said surface and exhausting it, said laydown drum having a circumferentially segmented annular-shape plenum comprising a multiplicity of circumferentially spaced transverse plenum segments, a partially masked foraminous laydown surface having oppositely contoured, cyclically undulating side edges defining cyclically circumferentially alternately spaced relatively widely masked and relatively narrowly masked sections of said surface and which sections corporately define the radially outwardly facing boundary of said plenum, and said air flow inducing means including constant differential pressure means for drawing air through said surface and said plenum from an air-entrained-fiber deposition chute as said drum is being rotated on its axis of revolution, the improvement comprising stationary adjustable air flow modulating means disposed adjacent the radially inwardly disposed boundary of an arcuate portion of said plenum circumferentially spanning a plurality of said transverse plenum segments so that the pressure drop induced by said means for drawing air through said surface can be adjusted across said relatively widely masked transverse sections of said lay-down surface without substantially affecting the pressure drop induced across said relatively narrowly masked transverse sections of said lay-down surface.
Claim 2
Dependent Claim
247 words
In an improved apparatus for continuously forming an air-laid fibrous web having oppositely phased, cyclically undulating side edges and a predetermined patterned basis weight distribution which apparatus includes a laydown drum having a forming surface, means for forming and directing a column of air entrained fibers onto said forming surface and depositing fibers on said forming surface, and air flow inducing means for drawing fiber-depleted air through said surface and exhausting it, said laydown drum having a circumferentially segmented annular-shape plenum comprising a multiplicity of circumferentially spaced transverse plenum segments, a partially masked foraminous laydown surface having oppositely contoured, cyclically undulating side edges defining cyclically circumferentially alternately spaced relatively widely masked and relatively narrowly masked sections of said surface and which sections corporately define the radially outwardly facing boundary of said plenum, and said air flow inducing means including constant differential pressure means for drawing air through said surface and said plenum from an air-entrained-fiber deposition chute as said drum is being rotated on its axis of revolution, the improvement comprising stationary adjustable air flow modulating means disposed adjacent the radially inwardly disposed boundary of an arcuate portion of said plenum circumferentially spanning a plurality of said transverse plenum segments so that the pressure drop induced by said means for drawing air through said surface can be adjusted across said relatively widely masked transverse sections of said lay-down surface without substantially affecting the pressure drop induced across said relatively narrowly masked transverse sections of said lay-down surface.
Claim 3
Dependent Claim
99 words
The improved apparatus of claim 1 wherein said stationary adjustable air flow modulating means comprises a stationary perforated plate having an array of apertures therethrough, a juxtaposed adjustable-position shutter plate having a field of holes therethrough disposed in corresponding relation to a portion of said array, and means for adjusting the position of said shutter plate with respect to said stationary plate to vary the degree of registration of the field of holes with the apertures of said portion of said array whereby the total effective open area of said stationary plate can be varied through a predetermined range.
Claim 4
Dependent Claim
47 words
The improved apparatus of claim 2 wherein said field of holes is substantially identical to the entire said array of apertures whereby the total open area of said stationary plate can be varied from full closed to the full composite open area of said array of apertures.
Claim 5
Dependent Claim
95 words
The improved apparatus of claim 2 further comprising a second shutter plate substantially identical to said shutter plate, and means for adjustably positioning them in transverse spaced relation and justaposed the oppositely disposed machine-direction edge portions of said stationary plate, said shutter plates being configured to be less than half the width of said stationary plate so that the shutter plates only provide means for modulating the air-flow through the machine-direction extending edge portions of the stationary plate and leave a machine-direction extending central portion of said array of apertures in said stationary plate unmodulated.
Claim 6
Dependent Claim
94 words
The improved apparatus of claim 1, 2, or claim 4 further comprising means for varying the fiber density in the column of fiber entrained air, and means for varying the rate of air flow through said laydown surface to control the average basis weight of said web formed on said relatively narrow areas of said laydown surface substantially independently from adjusting said shutter plate whereby adjusting said shutter plate will effectively control the degree of lesser basis weight of the portions of said web formed on the relatively wider areas of said laydown surface.
Claim 7
Dependent Claim
203 words
In an improved apparatus for continuously forming an air-laid fibrous web having oppositely phased, cyclically undulating side edges which apparatus includes a laydown drum having a forming surface, means for forming and directing a column of air entrained fibers onto said forming surface and depositing fibers on said forming surface, and air flow inducing means for drawing fiber-depleted air through said surface and exhausting it, said laydown drum having a circumferentially segmented annular-shaped plenum comprising a multiplicity of circumferentially spaced transverse plenum segments, a partially masked foraminous laydown surface having oppositely contoured, cyclically undulating side edges defining cyclically circumferentially alternately spaced relatively widely masked and relatively narrowly masked sections of said surface and which sections corporately define the radially outwardly facing boundary of said plenum, and said air flow inducing means including constant differential pressure means for drawing air through said surface and said plenum from an air-entrained-fiber deposition chute as said drum is being rotated on its axis of revolution, the improvement comprising air flow modulating means disposed inwardly of said transverse plenum segments so that the pressure drop through said surface can be adjusted across said lay-down surface such that the air-laid fibrous web has a predetermined patterned basis weight distribution.
Claim 8
Dependent Claim
203 words
In an improved apparatus for continuously forming an air-laid fibrous web having oppositely phased, cyclically undulating side edges which apparatus includes a laydown drum having a forming surface, means for forming and directing a column of air entrained fibers onto said forming surface and depositing fibers on said forming surface, and air flow inducing means for drawing fiber-depleted air through said surface and exhausting it, said laydown drum having a circumferentially segmented annular-shaped plenum comprising a multiplicity of circumferentially spaced transverse plenum segments, a partially masked foraminous laydown surface having oppositely contoured, cyclically undulating side edges defining cyclically circumferentially alternately spaced relatively widely masked and relatively narrowly masked sections of said surface and which sections corporately define the radially outwardly facing boundary of said plenum, and said air flow inducing means including constant differential pressure means for drawing air through said surface and said plenum from an air-entrained-fiber deposition chute as said drum is being rotated on its axis of revolution, the improvement comprising air flow modulating means disposed inwardly of said transverse plenum segments so that the pressure drop through said surface can be adjusted across said lay-down surface such that the air-laid fibrous web has a predetermined patterned basis weight distribution.
Claim 9
Dependent Claim
97 words
The improved apparatus of claim 6 wherein said air flow modulating means comprises a stationary perforated plate having an array of apertures therethrough, a juxtaposed adjustable-position shutter plate having a field of holes therethrough disposed in corresponding relation to a portion of said array, and means for adjusting the position of said shutter plate with respect to said stationary plate to vary the degree of registration of the field of holes with the apertures of said portion of said array whereby the total effective open area of said stationary plate can be varied through a predetermined range.
Claim 10
Dependent Claim
47 words
The improved apparatus of claim 7 wherein said field of holes is substantially identical to the entire said array of apertures whereby the total open area of said stationary plate can be varied from full closed to the full composite open area of said array of apertures.
Claim 11
Dependent Claim
95 words
The improved apparatus of claim 7 further comprising a second shutter plate substantially identical to said shutter plate, and means for adjustably positioning them in transverse spaced relation and juxtaposed the oppositely disposed machine-direction edge portions of said stationary plate, said shutter plates being configured to be less than half the width of said stationary plate so that the shutter plates only provide means for modulating the air-flow through the machine-direction extending edge portions of the stationary plate and leave a machine-direction extending central portion of said array of apertures in said stationary plate unmodulated.
Claim 12
Dependent Claim
94 words
The improved apparatus of claim 6, 7, or claim 9 further comprising means for varying the fiber density in the column of fiber entrained air, and means for varying the rate of air flow through said laydown surface to control the average basis weight of said web formed on said relatively narrow areas of said laydown surface substantially independently from adjusting said shutter plate whereby adjusting said shutter plate will effectively control the degree of lesser basis weight of the portions of said web formed on the relatively wider areas of said laydown surface.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |