Textiles: fiber preparation – Assembling – Article – screen-condensing
Patent
1991-04-26
1992-11-10
Schroeder, Werner H.
Textiles: fiber preparation
Assembling
Article, screen-condensing
28118, 28119, 264517, D01G 2500, A61F 1320
Patent
active
051612836
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method and to apparatus for forming an absorption body, wherein a mould having an air-permeable bottom is filled successively with airborne cellulose-fibres or fibres of some other absorbent material, with the assistance of subpressure, and wherein the absorption body formed in the mould is then pressed-out of the mould with the aid of overpressure.
It is normal practice in the technical field to which this invention pertains to utilize a subpressure for the purpose of filling moulds with absorbent material, by introducing a mixture of air and loose cellulose-fibres or the like into the mould and causing the air to pass through the mould bottom while depositing the fibres in the mould. Because the layers of fibre deposits are airpermeable in themselves, it is possible to deposit successive layers of fibres in this manner until the mould is full.
Swedish Patent Document 455 467 discloses an apparatus of this kind in which a vacuum box for creating a subpressure under a mould is divided into several separate compartments. Each compartment has means for controlling the subpressure and it is known from this publication to have subpressures in the compartments, which are increasing from compartment to compartment as a mould travels past the vacuum box. The filling of the mould is effected during the travel of the mould past the first compartment and the subpressures in the subsequent compartments is chosen for creating a suitable thickness and density of the fiber body in the mould.
In the present day manufacture of absorbent products, such as disposable diapers, incontinence guards, etc., it is a constant endeavour to use thinner and thinner absorption bodies, without losing the absorbency or absorption capacity afforded by the thicker absorption bodies which the thinner absorption bodies are intended to replace. This endeavour can be achieved, inter alia, by imparting different densities to different parts of the absorption bodies, which, among other things, results in improved liquid dispersion and consequently enables a greater part of the available absorption capacity of the body to be utilized more effectively. In this case, the absorption body may be formed from two discrete sub-bodies of mutually different densities, or may consist of a single entity having mutually different densities in different parts thereof.
Consequently, in order to ensure that the progressively more sophisticated configuration of such absorption bodies will actually have the effect intended, progressively higher demands are placed on the homogenity of the cellulose-fluff body produced, this body constituting the starting product on which further manufacturing processes are based.
The object of the present invention is to provide a method and apparatus for forming an absorption body whose mass of cellulose-fluff or corresponding material is essentially homogenous.
Accordingly, a method of the kind described in the introduction is characterized by varying the subpressure beneath the mould bottom in response to the variation in resistance to air-flow of the mould bottom and the cellulose-fluff which collects progressively in the mould. As a result, the air-flow through the mould can be maintained substantially constant and, correspondingly, the number of cellulose-fibres deposited in the mould per unit of time will also be essentially constant and compaction of the various parts of the body will be uniform. In the formation of homogenous absorption bodies, the inventive method enables the apparatus required to put the method into effect to be of simple and uncomplicated construction.
Accordingly, the invention also relates to apparatus for forming an absorption body, comprising a mould having an air-permeable bottom, means for supplying a mixture of air and loose fibres to the surroundings externally of the mould, a subpressure source for creating a subpressure beneath the mould and means for varying the subpressure beneath the mould, the apparatus including a pressure chamber located beneath the b
REFERENCES:
patent: 3177275 (1965-04-01), Brenner
patent: 3717905 (1973-02-01), Furbeck
patent: 4592708 (1986-06-01), Feist et al.
patent: 4627953 (1986-12-01), Johnson
patent: 4666647 (1987-05-01), Enloe et al.
patent: 4904440 (1990-02-01), Angstadt
patent: 4995141 (1991-02-01), Gould
Mohanty Bibhu
Molnlycke AB
Schroeder Werner H.
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