WO2014084780A1

WO2014084780A1 - A single-use toilet with a bag containing urea

Info

Publication number: WO2014084780A1
Application number: PCT/SE2013/051390
Authority: WO
Inventors: Anders Wilhelmson
Original assignee: Peepoople Ab
Priority date: 2012-11-27
Filing date: 2013-11-26
Publication date: 2014-06-05
Also published as: SE1251339A1; SE536753C2

Abstract

A single-use toilet intended to be used for urination and defecation, comprising a bag (3) of a size sufficient to be used for relieving oneself and for storing the excrements in the interior thereof,the bag being sealable after use, so as to retain said excrements within an interior volume thereof. An amount of urea is placed into said interior volume of the bag prior to said use, so as to secure sanitization of said excrements after use of the toilet, the sanitization being caused by way of said urea contacting the excrements in the bag,The bag is made from an essentially gas-tight, biodegradable material.A desired amount of urea,in the form of a solid material, is pre-filled into a pouch (4) which is smaller than said bag, and the pre-filled pouch is placed at the inside of said bag, adjacent to the bottom thereof, prior to said use of the toilet. The pouch is made of a material permitting said fluid to make contact with said urea after use of the toilet, whereby at least a major part of said amount of urea, which is soluble in said fluid, will dissolve and diffuse into said fluid, so as to make contact with substantially the total volume of excrements contained in the bag after said usage of the toilet, thereby effecting said sanitization. The new single-use toilet makes it possible to secure that an exact amount of urea is present in the bag, even at high production rates.

Description

A single-use toilet with a bag containing urea

FIELD OF THE INVENTION

The present invention relates to a single-use toilet intended to be used for urination and defecation, comprising

- a bag of a size sufficient to be used for relieving oneself and for storing the excrements in the interior thereof,

- wherein the bag is sealable after use, so as to retain said excrements within an interior volume thereof,

- wherein an amount of urea is placed into said interior volume of the bag prior to said use, so as to secure sanitization of said excrements after use of the toilet, said sanitization being caused by way of said urea contacting said excrements in the bag, and

- wherein the bag is made from an essentially gas-tight, biodegradable material that is impermeable to fluid during a period which is sufficient to inactivate at least a major part of pathogenic organisms, for example eggs and micro-organisms such as bacteria, viruses, parasites, etc., and possible other harmful biological materials being present in said excrements, making the excrements no longer harmful, before the wall material of the bag breaks due to material degradation.

The invention also relates to a method for manufacturing a bag for a single-use toilet. BACKGROUND OF THE INVENTION AND PRIOR ART

Such a single-use toilet is previously known from the international application published under No. WO 2008/105702 Al (PEEPOOPLE AB et al). In this document, it is explained how the toilet will provide a safe and inexpensive device for use at locations where there is inadequate sanitary infrastructure. In particular, the biodegradable bag of the single-use toilet has a number of advantageous properties:

- the bag has a simple structure and is inexpensive to manufacture,

- the bag is safe to handle, even for children, prior to being used as a toilet,

- the used bag, with its contents, is safe to store temporarily as-is, which is advantageous in areas where there are no large-scale garbage disposal arrangements,

- the used bag with its contents can be stored for many weeks, and can thereafter be used as a fertilizer.

A critical feature of the toilet is that the amount of urea in the bag is sufficient to inactivate various pathogenic microorganisms, such as bacteria, viruses, parasites, etc. during a limited period of time, being long enough to ensure that these microorganisms are inactivated when the material of the bag breaks and the contents leak out into the environment. However, the amount of urea should not be too large, for cost reasons and also to avoid excessive amounts of nitrogen-containing substances (in relation to potassium, phosphorus and micronutrients) that would make the material less useful as a fertilizer.

In the above WO document, it is suggested that the urea is applied onto essentially the complete inner surface of the bag, as a sufficiently thick layer, or in the form of a granulate or a powder spread out in the interior of the bag. There is no disclosure on how to feed and distribute the urea into the bag in practical terms, so that a balanced amount will be contained in each bag. Indeed, it will be a time-consuming process to apply an exact amount into each bag, and to spread it evenly into the interior thereof. Therefore, the production will be slowed down considerably. Alternatively, in case the urea is to be inserted manually into the bag by the user, there is a risk that the amount will be too large or too small, or it may be forgotten altogether. There is also a risk that the amount of urea will be positioned in a location where it will be ineffective for the intended sanitization process.

Furthermore, having to apply to a certain amount of a powder or granulate material, such as urea, into a bag will limit the production rate of bags, since the handling of such a material is difficult to keep tidy and precise when the powder or granulate must be mechanically handled by a manufacturing apparatus or machine operating at elevated velocities.

OBJECT OF THE INVENTION

A primary object of the present invention is to provide a single-use toilet with a bag containing an exact amount of urea, and a method of manufacturing such a bag for a single-use toilet, without slowing down the manufacturing process.

SUMMARY OF THE INVENTION

This object is achieved by providing a single-use toilet, wherein

- a desired amount of urea in the form of a solid material is present within a pouch, which is smaller than said bag, and which is situated at the inside of said bag, adjacent to the bottom thereof, and - said pouch has at least one wall portion permitting the fluid, which is present in the excrements, to make contact with said urea after use of the toilet, whereby at least a major part of said amount of urea, which is soluble in said fluid, will dissolve and diffuse into said fluid, so as to make contact with substantially the total volume of excrements contained in the bag after said use of the toilet, thereby effecting said sanitization.

By using a pre-filled pouch, or small inner bag, at least three major advantages are obtained.

First, the dosage can be controlled with exactness, so that a balanced amount of urea is fed into each bag, with a very small variation from bag to bag during manufacturing. Secondly, it is possible to position and attach the pouch as desired at the inside of the bag, to make sure that its contents will be present in a part of the bag where it is useful and will actively interact with the excrements contained in the bag after use of the toilet. Accordingly, it should preferably be mounted adjacent to the bottom of the bag. It would not give any effect if it were located in the uppermost part of the bag, where it might not contact the excrements at all, not even the liquid part of the excrements. Thirdly, using a contained pouch makes it possible to produce large numbers of bags according to the invention at a high production rate, since the handling of pouches rather than free powder or granulate is not mechanically sensitive and prone to dusting.

The invention is based on an insight of the mechanism that will occur when urea, in solid form, contacts the human excrements after use of the toilet. Although the feces are in the form of a relatively solid substance, it does contain a substantial amount of fluid. Therefore this fluid, which is contained in the excrements and which also contains the enzyme urease, will leak into the interior of the pouch and mix with the urea, thereby causing the urea to break down and form carbonates and ammonium, which in turn will act as a microbiocide and achieve the desired sanitization. Ammonium is highly soluble in water and will therefore diffuse into the fluid contents of the excrements and reach all parts of the feces in a relatively short time period. So, it is not necessary to spread the solid urea into all parts of the bag. Rather, it has turned out to work just as well with the solid urea being located in a small region - within the pouch - where it will contact the fluid part of the excrements after use of the toilet. Thus, even though the solid urea is contained within the relatively small pouch, it will dissolve and diffuse in the form of ammonium into the whole contents of the bag after use.

Another advantage is that ammonium, being a volatile compound, will quickly evaporate into the surrounding air, if the bag accidentally breaks before the sanitization process is completed. Therefore, the contents of the bag will present no more danger than ordinary feces, without any microbiocides in it.

Nevertheless, after a number of weeks, typically about four weeks, after use and sealing of the bag, the contents will no longer constitute a health hazard, and it will have transformed into a useful fertilizing substance when the wall material of the bag subsequently breaks and the contents leak out.

Further features and advantages of the invention will become apparent from the description below of a preferred embodiment of the single-use toilet according the invention, and a method of manufacturing such a toilet with a bag containing urea in a pouch.

BRIEF DESCRITION OF THE DRAWINGS

Fig. 1 shows, in a schematic side view, a single-use toilet comprising a flexible bag and an inner pouch;

Fig. 2 shows a portion of the wall of the bag, with a pouch attached to the inside of the wall; and

Fig. 3 illustrates schematically how the bag is manufactured from two coated webs in a machine, indicating a welding station and attachment of a pouch to the inside of one of the webs, before the welding station.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

A single-use toilet in the form of a flexible bag 3, illustrated in fig. 1, is of the kind disclosed in the above-mentioned specification WO 2008/105702 Al (PEEPOOPLE AB et al), The single-use toilet is arranged on a supporting structure 1 having an upper annular flange 2 serving as a seat ring for the user. The flexible bag 3 is dimensioned to accommodate, in its lower part, excrements from a single use by a human being. Its upper part 3b is dimensioned to be folded over the seat ring 2 of the supporting structure 1 and also to be sealed by a simple knot around itself, or by means of a string or some other sealing device (not shown). Typically, the bag 3 has a volume of about 0.8 liter, and a length of about 0.4 m.

In its lowermost part, adjacent to its bottom, the bag 3 has a small pouch 4 which is attached at the inside of the wall 3c of the bag 3. See also fig. 2, where a portion of the wall 3c is shown at a larger scale. The pouch contains an amount of urea, as will be explained further below.

The walls 3c of the flexible bag 3 are made of a biodegradable material. The material is such that it is impermeable to fluids during a period being required to inactivate most or all of the harmful biological materials, in particular pathogenic organisms, for example eggs and micro-organisms such as bacteria, viruses, parasites, etc., being normally present in the excrements after use of the toilet. In the present context, the statement that such harmful biological materials are "inactivated" means that a sufficiently large share of such materials are inactivated so that the contents of the bag 3 can be used as a fertilizer without a significant risk of spreading disease among humans.

The material of the bag 3 should preferably be a non-toxic, compostable material.

As disclosed in said WO document, the material is most preferably a biodegradable material selected from the group of polysaccharides, for example starch, amylopectin, amylose, cellulose derivatives, chitin/chitosan, alginate, carrageenan and aliphatic polyesters, for example poly-∑-caprolactone, polylactide, polyglycolide, polyadipine acid and polyhy- droxycanoates. Also, proteins and polyolefines, for example polyethylene, with suitable known additives, may be used.

It is feasible to use a material which is either a mono-material or a laminate of two or three of the materials mentioned above. Such layers may serve as a gas barrier and/or a moisture barrier. It is also possible that the bag is made of a material that is a copolymer and/or a polymer mixture of two or more of the said materials, or a combination of laminate, copol- ymers and/or polymer mixtures.

Generally, the walls of the bag should be made of a continuous film, a coated web or a sheet material, normally a laminate of two or more materials.

With such a wall material of the bag 3, it will eventually disintegrate. However, once the decomposition process has evolved long enough for the wall material to break open, the contents will leak out. The time to such breaking open of the bag 3 must be longer than the time indicated above, typically about four weeks, until the contents are no longer harmful. Therefore, it is preferred that the time to breaking open of the bag is at least 6 months, preferably 12 months. Before breaking open, the wall material of the bag 3 will prevent gases and fluids from leaking out. Accordingly, there will be no health hazard, because the excrements will be totally contained within the sealed bag 3 during the sanitization process.

As indicated above, the pouch 4 contains an amount of the compound urea (CO( H2)2) in solid form, either in one or more pieces, or as a granulate or a powder. The amount should be exact, so as to make sure that the amount is sufficient to inactivate the pathogenic organisms in the excrements, and yet to limit the amount so as to avoid excessive remaining amounts of nitrogen in the final substance to be used as a fertilizer. The amount of urea in each pouch (and in each bag) should be 2 to 8 g, depending on inter alia the temperature at the location of use and the environmental circumstances, typically 3 to 6 g.

According to the invention, the pouch 4 is placed at the inside of the bag, e.g. by means of an adhesive compound 5 applied to the inside surface of the wall 3 c (fig. 2) or, alternatively, to a surface portion of the pouch itself.

As appears from fig. 3, the bag is preferably manufactured by feeding two films or webs (or continuous sheets, possibly being laminated or coated with a gas-tight film) 8,9 of the bag material from a pair of bobbins 6,7 to a welding station 10, where the two webs are welded together along a line transverse to the webs, to form a closed bottom of each bag, and along the longitudinal edge portions of the webs, so as to close the sides of the bag as well. After the welding station (at a non-shown punching station), the two webs 8,9 are cut off, so that the bag units are separated from each other for easy handling and subsequent distribution and storage.

At least a portion of the wall surfaces of each pouch 4 is provided with a string or one or more patches of the above-mentioned adhesive material 5, which will make the pouch 4 stick to the underlying web 8 when it is pressed onto this web (arrow A in fig. 3), shortly in front of the welding station 10, at a predetermined distance d therefrom. In this way, the pouch 4 will not interfere with the welding process. Also, when the finished bag 3, with the prefilled pouch 4, is opened and made ready for use, the pouch 4 will swing down towards the bottom of the bag, as indicated in fig. 1.

Alternatively, it is possible to apply an adhesive material onto equidistant surface portions of one of the webs before the pre-filled pouches are placed onto these surface portions.

As a further alternative, although this would be rather complicated and possibly less reliable, it would be feasible to insert an end portion (or an attached piece of material) into the weld, so that the weld and the fixation of the pouch are effected in one stroke.

A still further alternative is to attach the pouches to one of the webs by means of a two- sided adhesive tape or pieces of such a tape.

According to an embodiment of the invention, the material of the pouch 4 is soluble in the fluid contained in the excrements, so that the pouch disintegrates quickly after use of the toilet and permits the fluid to mix with the urea. A suitable material for this purpose is polyvinyl-alcohol.

Alternatively, at least some wall portions of the pouch 4 is fluid permeable and is formed by a non-toxic, compostable material, so that the bag with all its contents is safe to store in the open air or at any suitable place, without polluting the environment. Preferably, it should be biodegradable as well, so as to form a part of the fertilizer substance after storage. In such an embodiment, the pouch is preferably made of one of the following materials:

a textile material,

a cellulose based material, a non-woven synthetic material,

a non-woven cellulose based material,

a thermoplastic material, or

a laminated structure of such materials.

The pouch material may be fluid permeable, at least at certain wall portions thereof, so that the material itself permits a flow or diffusion of fluid through it, and the urea in the pouch will make contact with the surrounding fluid being present in the excrements. Alternatively, the material may be structured with perforations, holes, or any kind of openings. Any openings should be small enough to retain the solid material of urea, at least during handling of the pouch before it is mounted at the inside of the bag 3, but large enough to permit the fluid to flow through the openings.

The size of the pouch 4 is not critical. However, it should preferably be substantially smaller than the bag 3, in particular having a length which is less than half of the bag 3 or, preferably, much smaller, such as the size of an ordinary tea bag.

Moreover, the pouch 4 may be integrated with one of the walls of the bag, as an inner pocket. Then, the pocket material may be formed as a pouch material, as specified above, whereas the opposite side of the pocket is formed by the wall of the bag 3 itself. With such a structure, it will be necessary to make a special filling apparatus for pre-filling the pocket with an exact amount of urea before the bag 3 is completed. Such tailor-made apparatus may be economically feasible if very large volumes of bags are to be produced.

Those skilled in the art may find other ways of producing the bags with pre-filled pouches at the inside, within the scope of the independent claims 1 and 11. For example, the bottom of the bags may be sealed by mechanical or chemical methods, rather than welding, and the materials of the bag and the pouch may be varied by those skilled in the art.

In the claims, the word "pouch" is intended to mean any small inner bag, pocket or container having the properties indicated above (permitting urea to make contact with the fluid being present in the excrements). Possibly, it may be suitable to place more than one pouch in each bag. Although it is advantageous to mount the pouch inside the bag at the time of manufacturing the bag itself, it is of course possible to place the pre-filled pouch or pouches at the inside of the bag in a separate step.

Claims

1. A single-use toilet intended to be used for urination and defecation, comprising

- a bag (3) of a size sufficient to be used for relieving oneself and for storing the excrements in the interior thereof,

- wherein the bag is made from an essentially gas-tight, biodegradable material that is impermeable to fluid during a period which is sufficient to inactivate at least a major part of pathogenic organisms being present in said excrements, making the excrements no longer harmful, before the wall material of the bag breaks due to material degradation,

c h a r a c t e r i z e d in that

- said amount of urea in the form of a solid material is present within a pouch (4)* which is smaller than said bag₇ and which is situated at the inside of said bag (3), adjacent to the bottom thereof, and

- said pouch (4) has at least one wall portion permitting the fluid, which is present in the excrements, to make contact with said urea after use of the toilet, whereby at least a major part of said amount of urea, which is soluble in said fluid, will dissolve and diffuse into said fluid, so as to make contact with substantially the total volume of excrements contained in the bag after said usage of the toilet, thereby effecting said sanitization.

2. The single-use toilet defined in claim 1, wherein said pouch (4) is made of a material that is soluble in said fluid, so that the pouch material dissolves and causes the urea to mix with said fluid being present in the bottom portion of said bag after use of the toilet.

3. The single-use toilet defined in claim 2, wherein said material of said pouch (4) is polyvinyl-alcohol, which is soluble in said fluid.

4. The single-use toilet defined in claim 1, wherein said pouch (4) has at least one fluid permeable wall portion, which permits said fluid, being present in the excrements contained in the bottom portion of the bag (3) after being used as a toilet, to flow into said pouch through said at least one wall portion and contact said urea.

5. The single-use toilet defined in claim 4, wherein said pouch (4) is made of a nontoxic biodegradable material.

6. The single-use toilet defined in claim 4 or 5

- wherein said pouch (4) is made of one of the following materials, with structural openings in said at least one fluid permeable wall portion:

- a textile material,

- a cellulose based material,

- a non-woven synthetic material,

- a non-woven cellulose based material,

- a thermoplastic material, or a

- a laminated structure of such materials.

7. The single-use toilet defined in claim 1, wherein said pouch (4) is mounted at the inside of said bag (3).

8. The single-use toilet defined in claim 7, wherein said pouch (4) is mounted adjacent to but at a distance from said bottom of the bag (3).

9. The single-use toilet defined in claim 8, wherein said pouch (4) is mounted with an edge portion being fixed to an inner wall of the bag, at a distance from the bottom end of said bag corresponding to a length of the pouch or less, and the pouch being oriented away from said bottom end, such that the pouch will swing down to a position adjacent to said bottom end when said bag, with said pouch, is opened and made ready for use of the toilet.

10. The single-use toilet defined in claim 1,

- wherein the material of said pouch (4) is adapted to retain said urea in solid form within said pouch, before use of the toilet.

11. A method of manufacturing a bag (3) for a single-use toilet,

- said bag having a size sufficient to be used for relieving oneself and for storing the excrements in the interior thereof,

- said bag being sealable after use, so as to retain said excrements within an interior volume thereof,

- said method comprising the step of placing an amount of urea into said interior volume of the bag prior to said use of the toilet, so as to secure sanitization of said excrements after use of the toilet, said sanitization being caused by way of said urea contacting said excrements in the bag,

- the bag being made from an essentially gas-tight biodegradable material that is impermeable to fluid during a period which is sufficient to inactivate at least a major part of pathogenic organisms being present in said excrements, making the excrements no longer harmful, before the bag breaks due to material degradation,

c h a r a c t e r i z e d in that

said step of placing an amount of urea into said interior volume of the bag comprises

- pre-filling a pouch (4), being smaller than said bag (3), with said amount of urea in solid form, and

- placing said pre-filled pouch (4) at the inside of said bag (3), adjacent to the bottom thereof, in connection with manufacturing the bag,

- wherein said pouch (4) has at least one wall portion permitting said fluid to contact said urea after use of the toilet.

12. The method of manufacturing a bag as defined in claim 11, wherein

- the bag (3) is made from two webs of said gas-tight material being fed to a welding station, where they are welded together into bag units, and

- said prefilled pouches (4) are being placed onto one of said webs before said welding station, at least one pouch for each one of said bag units.

13. The method of manufacturing a bag as defined in claim 12, wherein

- said prefilled pouches (4) are provided with an adhesive material at a surface portion thereof before they are placed onto one of said webs.

14. The method of manufacturing a bag as defined in claim 12, wherein - an adhesive material is applied onto equidistant surface portions of one of said webs before said pre-filled pouches (4) are placed onto said surface portions.