WO1994021437A1

WO1994021437A1 - Method for making an anti-bedsore mattress

Info

Publication number: WO1994021437A1
Application number: PCT/FR1994/000293
Authority: WO
Inventors: Georges Roux
Original assignee: Georges Roux
Priority date: 1993-03-18
Filing date: 1994-03-17
Publication date: 1994-09-29
Also published as: FR2702652A1; FR2702652B1

Abstract

A method for making an anti-bedsore mattress by moulding a mattress (4) out of an anti-bedsore open-cell foam (2), said mattress consisting of a plurality of juxtaposable modules (3). Each module mould has a bottom portion (5) comprising a plurality of raised portions (6) with, on the upper mould surface, a plurality of wafer-like pads, and an upper mould portion forming a lid (8) of which the surface facing the mattress base (7) is provided with a plurality of ripples (10), particularly longitudinal, transverse or intersecting ripples for preventing the formation of oversize air bubbles during moulding. Furthermore, an agent layer (12, 13) is sprayed onto the interface between the mould walls and the foam (2) contacting same before applying the mixture of various liquid components for forming the expanded and moulded foam.

Description

"Method of manufacturing anti-decubitus mattresses"

The present invention relates to a method of manufacturing mattresses for therapeutic applications in the field of prevention and treatment of bedsores.

Anti-decubitus supports aim to minimize overpressure and shearing of an individual's risk areas (occiput, sacrum, shoulders, heels, for example in supine position) during prolonged bed rest.

The known methods mainly reside in the use of sophisticated technologies, such as in particular fluidized beds which increase the surface of the patient's contact areas on the support and reduce the pressure by the action of a fluid, as described in FR-1,516,528; or simpler ones such as waffle-shaped mattresses. These mattresses, in one piece or made up, for easier handling, of modules, the juxtaposed assembly having the dimensions of a mattress, are of cellular foam. Each module comprises a bottom part or sole and an upper part having reliefs of the type of those of a waffle mold, that is to say comprising a plurality of juxtaposed studs produced by cutting or molding. These various lift processes have the respective major drawbacks, one is costly to use and maintain often reserved for serious pathologies such as burns, the other requires cutting operations, either to obtain the final shape, either to eliminate bad aspects of the surface, such as large bubbles or air inclusions a few centimeters deep on the visible face of the sole, operations which require long and costly manipulations.

The present invention proposes to provide solutions making it possible to remedy the drawbacks of the previously known methods.

Consequently, the subject of this invention is a method of manufacturing an anti-decubitus mattress, characterized in that a molding operation is carried out on a mattress, in cellular foam, anti-decubitus consisting of a plurality of modules. juxtaposed, each module mold comprising a bottom part having on its upper face a plurality of reliefs or cells for waffle-type studs and a part of the mold forming a cover, provided on its face facing the bottom with a plurality of undulations in particular longitudinal, transverse or crossed, in order to avoid the formation of air bubbles of excessive volume; it is further provided that prior to the operation of depositing and molding the mixture of the various constituents of the foam, a layer of an agent is projected onto the interface between the walls of said mold and the foam coming into contact.

Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate an embodiment thereof devoid of any limiting character. In the figures:

- Figure 1 is a perspective view of a mattress obtained by the implementation of the method, object of the invention;

- Figure 2 is a sectional view, in front elevation of an unfilled mold, used for the implementation of the method;

- Figure 2a is a detail on a larger scale of the roughness present on the cover;

- Figure 3 is a sectional view, in front elevation of a mold filled with foam; - Figure 4 is a sectional view of a mold being filled with the expanding foam of the future module.

According to a preferred embodiment of the method for manufacturing an anti-decubitus mattress, refer to FIG. 1 on which we can see a mattress obtained according to the implementation of the method, object of the invention; thus, raised studs 2 obtained by separation of the waffle-shaped mold are retained by their respective bases on the extent of a sole 7 made of a material similar to the studs. Each of the modules thus produced is joined by one of their common faces, so as to conform a mattress. Therefore, in a plurality of molds 1, the shape and size of which are adapted to the desired product, a

RULE SHEET 16 molding of a polyurethane foam 16 obtained by the chemical reaction of at least two liquid constituents such as in particular polyol and isocyanate, or latex in order to obtain, after the polymerization reaction has stopped, a plurality 3 juxtaposable modules intended in particular to conform mattresses.

The bottom 5 of each mold 1 is provided with a plurality of reliefs 6 or recesses or hollow studs, directed downwards, in particular of the waffle type, this advantageous configuration eliminates the shearing effects of a patient / mattress contact surface uniform, which generally in this case is a source of pressure ulcer formation.

The liquid mixture of the constituents of the foam is poured or deposited in the same mold 1 in each cell (so as to avoid the problems of migration of the foam in the cells if the deposition was carried out at one or even more points of the mold but not in all the alveoli). The liquid constituents of the foam after reaction between them expand and form a cellular foam which rises in the form of a dome above each cell (FIG. 4) and abuts on the cover leaving the residual inclusions 17; ambient mold air and gas.

In order to minimize the size of the gas bubbles which emerge through the entire volume of said modules during the foaming or polymerization reaction, a plurality of said molds 1 are available and facing the bottom, a plurality of covers 8, each of the internal faces 9 facing the foam 16 is provided with a plurality of asperities 10 shaped in particular in the form of small longitudinal, transverse, crossed corrugations. These asperities 10 in relief make it possible to break up, distribute all the small air bubbles which present themselves and optionally direct them towards a plurality of vents 11 arranged on said covers 8, then towards the atmosphere. These vents 11 are blocked as soon as foam appears on the outside. The quantities of gas trapped at the foam / cover inter ace and particularly in the areas of crossing are minute and thus allow not to touch up, in the present case, by surfacing and by removing material, the seat surface of said modules; the amount of waste therefore becomes negligible. Furthermore, the absence of cavities in the modules of large volume originating from a residual air pocket considerably improves the behavior of said mattress over time; in fact, the patient's weight is distributed uniformly over the entire surface of said mattress, there is no sinking of non-homogeneous areas, the deformation of the mattress is identical in all places.

Provision is also made to provide a few walls constituting the mold modules with these same roughness, the aesthetic effect of the finished product is identical on all its faces.

It is also possible, in order to mask the multitude of tiny air or gas cells which reside on the surface of the foam, to spray a paint 12 called the mold bottom, which can advantageously have curative or hypoallergenic properties, on the whole. walls of said molds 1 and said covers 8, it being understood that this finishing operation will be subsequent to that of the deposition of a demolding wax 13 before the establishment of the foaming mixture. Pouring of this foam is almost always carried out with the lid open so that most of the gas evolution spreads to the atmosphere as quickly as possible and especially before the start of the polymerization reaction, which also facilitates uniform and homogeneous distribution. foam within said modules, it being understood that care will have been taken to distribute the initial mixture uniformly at the bottom of each cell 6 of the mold. Said mold splitting paint which forms the surface coating of the module adheres perfectly to the polymerized foam, it behaves like a skin, thus masking all the small cells. By this advantageous process, it is impossible for said skin to conceal a large cavity which could have remained if said cover had not been put in place.

The surface coating 12 is not very permeable to air. To

E 26 that during the patient's sleeping, the air contained in the mattress can be evacuated, a plurality of holes 14 is provided by cutting, punching or any other process, before or after complete demolding of the thickness of the surface coating preferably on the seat face of said mattress (face least exposed to contamination from the patient) for the evacuation of the air contained in the module of the mattress during bed rest. Depending on the open surface of the holes 14, the air escapes more or less quickly. The present invention is advantageous in its embodiment since such a mattress more or less slowly returns to its original shape after the stress has been removed, it easily replaces mattresses made from memory foam, which are very sensitive to the ambient temperature: thus, for a cold temperature, one obtains a hard foam, while for a hot temperature, one obtains a soft foam, the modifications of reaction of the support facilitating the appearance of bedsores.

According to the invention, the implementation of this process can be applied to the production of any foam envelope contributing to the comfort of an individual, such as cushions, neck rests, backrests, poufs ..., or as a material protection for packaging fragile products.

It remains to be understood that the present invention is not limited to the exemplary embodiments described and shown above, but that it encompasses all variants thereof.

Claims

1 - Method for manufacturing an anti-decubitus mattress, characterized in that a molding operation is carried out on a mattress (4), in foam (16) cellular, anti-decubitus consisting of a plurality of modules ( 3) juxtaposed, each module mold comprising a bottom part (5) having on its upper face a plurality of reliefs (6) or cells for pads of the waffle maker type and a part of the mold forming a cover (8), provided on its face facing the bottom of a plurality of corrugations (10), in particular longitudinal, transverse or crossed, in order to avoid the formation of air bubbles of excessive volume; it is further provided that prior to the operation of depositing and molding the mixture of the various constituents of the foam, a layer of an agent (12, 13) is sprayed onto the interface between the walls of said mold and the foam ( 16) coming into contact. 2 - Process for manufacturing an anti-decubitus mattress according to claim 1, characterized in that a foam (16) of polyurethane type obtained by the chemical reaction of at least two liquid constituents is produced. in particular polyol and isocyanate, or latex with a view to obtaining, after the polymerization reaction has been stopped, a plurality of juxtaposable modules (3) intended in particular to conform mattresses (4).

3 - A method of manufacturing an anti-decubitus mattress according to one of claims 1 or 2, characterized in that, to reduce and distribute as much as possible the size of the air bubbles (17) which emerge through everything the volume of said modules during the foaming and polymerization reaction, there are on all of said molds (1) and facing the bottom, a plurality of covers (8) each of which faces (9) internal facing screw of the foam (16) is provided with a plurality of asperities (10) shaped in particular in the form of small longitudinal, transverse, crossed corrugations. 4 - A method of manufacturing an anti-decubitus mattress according to any one of the preceding claims, characterized in that there is provided a plurality of vents (11) disposed on lesdit covers (8) to evacuate the gases or the air from the chemical reaction to the atmosphere.

5 _ method of manufacturing an anti-decubitus mattress according to any one of the preceding claims, characterized in that a paint (12) is sprayed, which can advantageously have curative or hypoallergenic properties, on all of the walls said modules (1) and said covers (8), it being understood that this finishing operation will be subsequent to: that of the deposition of a demolding wax (13) before the establishment of the foaming mixture, the pouring of this foam (16) practically always carried out with the lid open, thus facilitating the uniform and homogeneous distribution of the foam within said modules.

6 - A method of manufacturing an anti-decubitus mattress according to any one of the preceding claims, characterized in that it is provided that with the surface coating, when the patient is sleeping, the air contained in the mattress can evacuate and a plurality of holes (14) are made on the seat face of said mattress for the evacuation of gases which escape more or less quickly depending on the open surface of the holes.

7 - Mattress obtained by the implementation of the method according to any one of the preceding claims, characterized in that it comprises a series of foam modules provided with asperities (10) and studs (4) in relief and coated on the surface with a layer of paint (12).