WO2003013261A1 - Sealing animal carcass orifices - Google Patents

Abstract

The present invention relates to a moulding mixture for use in moulding a plug for sealing an orifice of a slaughtered animal carcass the mixture including: (i) 40 to 60 wt% plant fibre pieces optionally combined with about 0 to 2 wt % starch with the plant fibre pieces; and (ii) 10 to 55 wt % water and 3 to 10 wt % one or more water-soluble binding agents or adhesives The invention further relates to the plug manufactured usin.g the moulding-mixture, a process and method for manufacturing the plug by moulding and a method for eviscerating a slaughtei'ed'animal comprising use of the plug.

Description

Sealing Animal Carcass Orifices

Field of the invention

The present invention relates to the slaughtering of animals and more particularly to sealing an orifice of a slaughtered animal carcass.

Background of the invention

In this specification, unless the contrary is expressly stated, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date part of the common general knowledge; or known to be relevant to an attempt to solve any problem with which this specification is concerned

Various methods have been proposed for eviscerating the carcass of a slaughtered animal in a manner which minimises the risk of the contents of various viscera such as the stomach, bowel or urinary tract contaminating the carcass.

It is known to use a plug for sealing an orifice of a slaughtered animal carcass such as the throat, anus or urinary tract. Such plugs have been made from various materials including plastics materials such as polyethylene. After the plug has been secured in place, the carcass can be eviscerated and the viscera removed for subsequent processing.

One example of such prior art is described in International patent application

PCT/AU98/00818 (International Publication Number WO 99/16320) by inventors Finney and Gregor. This Finney and Gregor specification describes a process and anal seal for sealing the anus of the carcass of a slaughtered animal. The anal seal includes a plug for insertion through the anus and into the rectum of the carcass and a clamp retaining means to keep the plug in place to facilitate processing of the carcass. The plug illustrated in Finney and Gregor is a frustoconical plastics moulding.

One of the difficulties with this arrangement is that the plastics anal seal needs to be retrieved from the viscera before the viscera can undergo further processing. To address this problem plugs have been made from recycled paper. However, such recycled paper plugs are prone to absorb liquids which leads to a breakdown in their structural integrity. This in turn can lead to contamination of the carcass as body fluids leak past the saturated plug.

Accordingly, there exists a need for a plug which can maintain its structural integrity in the environment in which it is used and yet which does not need to be retrieved from the viscera following removal from the carcass. Summary of the invention

The present invention accordingly provides, in one embodiment, a plug for sealing an orifice of a slaughtered animal carcass, the plug being formed from a material containing compacted plant fibre pieces bound with one or more binding agents to form a plug capable of absorbing body fluids without loss of structural integrity. Preferably, a plug according to the invention is formed from a moulding mixture including:

(i) 40 to 60 wt% plant fibre pieces and optionally combining 0 to 2 wt% added starch with the plant fibre pieces; and (ii) 10 to 55 wt % water and 3 to 10 wt % one or more water-soluble binding agents or adhesives. The term "body fluids" is used throughout the present specification and claims to include all fluids in a carcass and may include the fluid components of bowel contents and urinary tract contents as well as any other fluid material in the carcass.

The plug is preferably shaped to fit the orifice to be sealed. The plug may have a cap which may be partly hollow. The cap may have a generally conical or frustoconical shape. Preferably, the plug has a somewhat rounded profile to reduce the likelihood of perforating the wall of tissue forming the orifice to be sealed. In one preferred arrangement the plug is bell shaped. The plug may include a shaft or handle depending from the cap. With this arrangement the cap may be inserted into the orifice using the shaft or handle. When the cap is generally bell shaped with a handle extending from within the cap the plug may appear to have a generally mushroom shaped profile.

Alternatively, instead of including a shaft or handle the plug may be shaped so as to removably receive one end of a long handled tool used to insert the plug in an animal carcass. The shaping may include the provision of a flange or seat for receiving the tool. Where the plug is bell shaped, the flange or seat is typically provided adjacent the periphery of the bell shape.

Although the plug preferably does not have any sharp comers liable to tear the tissue forming the orifice, the outer surface of a plug according to the present invention need not necessarily be smooth. It has been found that a somewhat rough surface which can be formed by fibre pieces projecting outwardly from or being recessed inwardly from the general plane of the surface can be advantageously used in accordance with the present invention. The nature and extent of any such projection or recess is preferably such that they do not render the cap liable to tear the tissue forming the orifice. The plug may be formed by a process provided in accordance with another aspect of the present invention. The plug is preferably formed from biodegradable materials. Most preferably the plug is formed from materials which need not be retrieved from the viscera. Accordingly, the present invention provides, in yet another embodiment, a method for removing the viscera from the carcass of a slaughtered animal including the steps of:

(a) inserting a plug provided in accordance with the present invention into one or more orifices of the carcass to substantially seal the orifice against leakage of body fluids therefrom;

(b) severing the viscera from the carcass by cutting the tissue surrounding the orifice; and

(c) removing from the carcass the viscera with the plug sealingly engaged thereto.

It is to be appreciated that in accordance with the present invention not all orifices of a carcass are necessarily sealed.

It is also to be appreciated that in accordance with the invention the plug may be inserted into an orifice after the orifice is severed from the carcass. In this arrangement, step (b) of the above described method would take place prior to step (a).

A plug according to the present invention may be formed by a process as described herein which involves the moulding of a moulding mixture at elevated temperatures and pressures sufficient to compact and bind plant fibre pieces to form a unitary article.

The present invention accordingly provides, in a still further embodiment a moulding mixture for use in moulding a plug according to the present invention, the mixture including:

(i) 40 to 60 wt% plant fibre pieces optionally combined with about 0 to 2 wt % starch with the plant fibre pieces; and

(ii) 10 to 55 wt % water and 3 to 10 wt % one or more water-soluble binding agents or adhesives In another aspect the present invention, provides a process for manufacturing a plug for sealing an orifice of a slaughtered animal carcass, the process comprising the following steps:

(a) preparing a moulding mixture by:

(i) taking 40 to 60 wt % plant fibre pieces and optionally combining 0 to 2wt % added starch with the plant fibre pieces; and (ii)adding thereto 10 to 55 wt % water and 3to 10 wt % one or more water-soluble binding agents or adhesives;

(b) pouring the mixture into a mould, the mould being at a temperature of at least 60°C; (c) subjecting the mixture in the mould to a temperature in the range of 15 to 60 °C and a pressure in the range from 1000 to 7000 PSI for a period of time such that a portion of the water in the mixture is converted to steam which causes the mixture to fill the mould while remaining in a readily mouldable state;

(d) reducing the pressure so that steam forms within the mould without causing an explosion whilst maintaining the mixture in a readily mouldable state;

(e) increasing the temperature and pressure to a temperature in the range from 100 to 300°C and a pressure in the range of 500 to 1500 PSI ;

(f) removing the steam or allowing the steam to escape until the moulded plug is substantially dry; and

(g) removing the substantially dried and moulded plug from the mould.

In a prefeixed embodiment, the process further comprises the steps of:

(h) at least partially coating the moulded plug with one or more binding agents or adhesives; and (i) heating the coated moulded plug to substantially dry and cure the coating.

The invention involves employing the action of the steam to force the mixture to be distributed throughout the mould. Any excess solids material will thus be forced out of the mould by the action of the steam. Once the action of the steam has spread the mixture throughout the mould, the steam is removed or escapes through the gap or a valve. Without this steam action, the solids in the mixture would not spread throughout the mould and may end up being compressed at the bottom of the mould in which case the mixture would no longer be in a readily mouldable state.

Preferably the process comprises a further step of trimming the edges of the plug prior to coating the plug in step (h). Typically, such trimming is conducted using a die-cut machine. Other methods for trimming may also be used within the scope of the invention including polishing and/or sanding down the edges of the plug.

Since the main ingredient in the mixture is plant fibers which are bonded together by an adhesive which hardens as it cures, the cured plug will not disintegrate immediately upon contact with liquid. Depending on the density of the plug (and thus the porosity of the plug), the plug will take a minimum often minutes before it starts disintegrating and could last as long as one hour. The density of the plug is dependent on the pressure applied during formation of the plug. Therefore, the plug is liquid-resistant enough to withstand treatment with fluid resistance agents.

The cured plug can be further treated with a body fluid resistance material A body fluid resistant coating may comprise any appropriate material such as wax or a water soluble latex base. Typically, the coating is non-toxic. For environmental reasons, preferably the coating is a biodegradable material such as a water soluble wax. Alternatively, the coating is a non- biodegradable material such as a wax which is soluble in a non-aqueous solvent, a polymeric material such as a vinyl or polyurethane-based polymer or a conductive paint such as Statichan™. Preferably, the plug is at least partially coated with Neoprene to make it body fluid resistant since this coating has FDA approval and is environmental friendly. The coating process can be by way of brushing, spraying or dipping or any other convenient method. It has been found advantageous in accordance with the present invention to only partially coat plugs with materials suitable to reduce the rate of absorption of body fluids by the plug. In one arrangement according to the present invention that portion of the plug which is to contact the tissue surrounding the orifice is coated. The remainder of the plug preferably remains substantially uncoated with materials effective to resist absorption. In one particularly preferred arrangement according to the present invention the plug is hollow and a body fluid resistance material applied to the internal surface of the hollow plug. In this arrangement it is preferred that no coating is applied to any external surface. A plug according to the present invention may additionally include an absorbing ingredient. The absorbing ingredient may be any ingredient suitable to absorb or adsorb body fluids. A carbon powder such as carbon black is particularly suitable for use as an absorbing ingredient in accordance with the present invention although other desiccants may be suitable such as, for example, silica gel.

The period of time for which pressure in the range from 1000 to 7000 PSI is applied in step (c) is preferably short and most preferably in the range of from 3 to 10 seconds. Preferably, in step (c) the mixture in the mould is subjected to a temperature of about 29 °C. Preferably, the pressure in process step (d) is reduced to a pressure in the range of from 500 to 1500 PSI before the pressure is increased in process step (e). Most preferably the pressure in process step (d) is reduced to atmospheric and then increased in process step (e) to a pressure in the range of from 500 to 1500 PSI more preferably about 1000 PSI. Preferably, the temperature in process step (e) is increased to about 140°C. Process step (f) typically occurs for a period of time in the range of from 10 seconds to 30 minutes or longer till the plug is substantially dry at a temperature in the range of from 100°C to 250°C.

The plant fibers can come from any source. For example, suitable plant fibres may be chosen from the group comprising rice stalks, wheat stalks, sugar cane, com leaves, banana leaves, com crops, roots, grass, flowers, recycled paper or combinations thereof. The size of the fibers affects the texture of the final plug. The requirements of the final plug will dictate the size of- the fibers required. Preferably, the length of the plant fiber pieces used to produce a plug according to the present invention is in the range of from 0.1mm to 5 mm. More preferably, the length should be between 1 mm to 2 mm. However it is possible to use plant fibers which have been ground smaller than 1 mm maximum dimension, eg. powdered.

The binding agents or adhesives which are used to bind the fibres are preferably water soluble and most preferably are environmental friendly and not required to be removed from the viscera. It is preferred that non-biodegradable plastics or synthetic polymers are not used as binding agents in the present invention so that the process provides a biodegradable plug. However, it is to be appreciated that biodegradability of the binding agents or adhesives is not essential. Preferably, water based biodegradable adhesives are used in accordance with the present invention so that the end plug is biodegradable. Preferably, latex -based adhesives, such as Neoprene, are used in accordance with the invention. Preferably, any added starch used in accordance with the present invention is selected from the group comprising tapioca flour, ground sweet potatoes or any other root powder, com starch, flour and combinations thereof. While corn starch and flour are suitable for use as added starch in accordance with the present invention the results are not as good as when other starch sources are used. There is no need to modify any added starch prior to processing.

The fiber and any flour are mixed together initially in process step (a)(i) to produce an even mixture. Further, if the liquid ingredients contact the flour before it is evenly mixed in, the flour will form lumps and this will create holes in the plug as the starch is removed during the process. Once all the ingredients are combined in process step (a)(ii), the mixture is stored in a sealed container until required for process step (b) to prevent the mixture from drying out. The mixture is preferably stored at room temperature prior to use to prevent hardening. The mixture may be stored at a temperature in the range from the freezing point of the mixture to about 25°C. Preferably, the mixture is stored at a temperature in the range from 15 to 25°C. Further, at higher temperatures there is a possibility that mould will form because of the combination of water and an organic mixture. Preferably, process step (a) occurs at a temperature at or below 25°C.

The water used can be of any quality. For example, non-potable water such as sea water may be used as well as normal utility water. The water is converted to steam during the process. This aids in spreading the mixture evenly in the mould. The mixture does not foam because the pressure prevents the mixture from expanding, and the action of the steam is directed towards spreading the mixture throughout the mould. Once the spreading is complete, the steam is removed to allow the plug to dry.

The amount of pressure applied to the mould will affect the density of the final plug. The denser the plug, the harder it is. Therefore, if a more flexible plug is desired then a lower pressure should be used. When the pressure is applied to the mould, any excess material will be squeezed out of the mould. Preferably, the pressure applied in process step (c) is at about 4000 PSI. The strength of the plug will depend on four factors:

(a) The fibre pieces. The finer the pieces, the higher the density and hence the greater the strength of the plug.

(b) The type of adhesive. Different types and grades of adhesives contribute differently to the strength of the plugs. The different crystallization rates and viscosities of different adhesives result in different plugs. Crystallization determines the rate of initial strength development. The faster the rate of crystallization, the faster the rate of strength development. Viscosity influences the inherent strength of the adhesive film, the solution viscosity, and solids content. The higher the polymer viscosity, or the higher the molecular weight, the higher the film strength, the higher the adhesive viscosity, or the lower the solids at a given adhesive viscosity.

(c) The structural design of the mould. The product design may enhance the strength of the overall product. For example, a plug with ribs or flanges will be stronger than one without.

(d) The type of fibre. For example, sugar cane fibre provides a moulded product that is inherently resilient but not brittle. Conversely, rice husks tend to provide a product that is hard, but comparatively brittle. The mould is typically made of metal and consists of two parts - a top and a bottom part. However, it is possible to use moulds which come in three or more parts provided that there is still a top and a bottom part. In use, the mould is preferably compressed vertically, that is, in a downward and upward manner so that the top part is compressed against the bottom part. Typically, there is a gap of 1 mm between the top and bottom mould parts through which the steam and excess mixture can escape.

The surface of the mould is preferably smooth, that is the surface is not rough or feels like sand paper. Any protrusions in the mould must not interfere with the removal of the plug from the mould. The mould must be adapted to enable the steam to escape. For example, the mould may comprise a vent for steam release. The shape and size of the mould will depend on the plug to be produced.

The mould may be heated by attaching heaters to the mould or passing the mould through an oven. The pressure may be provided by any known means including a hydraulic press, pneumatic press or mechanical press. Typically, the pressure is provided by a hydraulic press as these presses provide a consistent pressure.

A plug in accordance with the present invention may be advantageously used during evisceration to minimise the risk of body fluids contained in the viscera contaminating the carcass. When disposed of, plugs produced by the process of the invention will breakdown and disintegrate to form substances which are not detrimental to the environment. This is because all of the materials used are non-toxic and are mostly natural and edible. If the plugs are left to decompose after use, the resultant manure can be used as a fertilizer because of the fact that the main ingredient of the plug is plant fibers.

Further, the plant fibers may be obtained from the unwanted parts of crops such as rice- stalks, sugar cane pulps or any other fibers that are not directly consumed. This helps to dispose of such waste from harvesting sites, factories etc. which would otherwise be disposed of by burning and thus causing air pollution. The use of such raw material helps to reduce this air pollution.

Further, during the process of the invention, bacteria are killed due to the high temperatures being applied.

A mould used in accordance with the present invention may include one or more valves in the top and/or bottom ends of the top and/or bottom parts of the mould to enable steam to be removed wherein the openable valves are closed when the mixture is placed into the mould and then the valves open when the steam needs to be removed. The valves enable the steam to be removed from the mould so that the plug will dry out faster. Further, the steam is removed more quickly and the plug is less likely to be burnt.

The valves are mechanically operated. Once the temperature in the mould has risen above the boiling point of the water, this indicates that mixture will be spread evenly throughout the mould and the valves can be opened to release the steam. By the time that the mixture has spread evenly throughout the mould, it will have hardened just enough so that it does not enter into the valve with the steam. The valves are closed when the mixture is placed into the mould and when the pressure is applied to the mould, thus the mould is-totally closed except the gap between the top and bottom parts of the mould. As the water or moisture in the mixture is converted into steam, this steam will rush upward forcing the mixture to move into all the open spaces thus filling up the whole mould. Extra or excess mixture will be squeezed out of the mould. Normally the mould will be opened in process step (d) when the temperature reaches between 100 and 120 °C and, preferably at about 110°C.

The valves shorten the time for the plug to be dried and thus shorten the processing time.

Further without using any valve, the steam will take longer to escape through the side and out through the gap between the top and bottom parts of the mould. If the steam takes too long to remove, the heat would cook or bum the center portion of the plug while the sides are only just dry.

Preferably, there is one valve every 4 square inches. The valves cannot be placed in the sides of the mould as this would impede the proper spreading of the mixture to be moulded.

If the valve was fixed to the side of the mould, steam would escape through it, thus reducing the pressure inside. This reduced steam pressure may cause the mixture not to flow to the space above the valve and create an incomplete plug.

All proportions in this specification are in percentage weight.

Description of the drawings

The invention will now be further explained and illustrated by reference to the accompanying drawings in which:

Figure 1 is a flow diagram of the process according to the invention; and

Figure 2 is a schematic of an overview of the process.

Figure 3 is a perspective view of a mould open;

Figure 4 is a perspective view of the mould in Figure 3 filled with the mixture;

Figure 5 is a perspective view of the mould in Figure 4 closed and under pressure with the valve closed; Figure 6 is a perspective view of the mould in Figure 5 with the valve now open;

Figure 7 is a perspective view of the mould in Figure 6 opened with the plug removed; and

Figure 8 is a cross-sectional view of a mould according to another embodiment of the invention.

Figure 9 shows a cow throat plug according to a preferred embodiment of the invention wherein:

Figure 9a is a front view of the plug

Figure 9b is a-plan view of the plug of figure 9a, and

Figure 9c is a perspective view of the plug of figure 9a. Figure 10 shows a sheep anal plug according to a preferred embodiment of the invention wherein:

Figure 10a is a front view of the plug

Figure 10b is a plan view of the plug of figure 10a, and

Figure 10c is a perspective view of the plug of figure 10a. Figure 11 shows a pig anal plug according to a preferred embodiment of the invention wherein:

Figure 1 la is a front view of the plug

Figure 1 lb is a plan view of the plug of figure 11a, and

Figure 1 lc is a perspective view of the plug of figure 11a. Figures 12 to 15 are graphs of water content versus time for four different types of animal plugs according to the present invention, wherein

Figure 12a relates to an uncoated sheep anal plug

Figure 12b relates to a sheep anal plug partially coated with Michem emulsion 43040

Figure 13a relates to an uncoated sheep anal plug

Figure 13b relates to a sheep anal plug partially coated with EcoDEX Plus waterbased spray lacquer

Figure 14a relates to a sheep anal plug coated on its inner surface with Michem emulsion 43040

Figure 14b relates to an uncoated pig anal plug

Figure 15a relates to a sheep anal plug coated on its inner surface with EcoDEX Plus waterbased spray lacquer, and

Figure 15b relates to an uncoated pig anal plug. The use of a mould as shown in the drawings will now be described in relation to following example of a preferred embodiment of the process provided by the invention.

Preferred Compositions

Moulding mixtures having compositions according to the present invention were prepared.

The proportions of components present in the mixture are set out as examples 1 to 40 in the following table: Examp Flour/stare Binder Water Fiber Calcium Total % of le h (gm) (gm) (gm) (gm) carbonate (gm)- starch

(gm)

Tapioca Latex Tap water Sugar cane

Flour water base pulp (degradabl e)

1 6.0 10.0 30.0 40.0 0.0 86.0 7.0%

2 6.0 8.0 30.0 40.0 0.0 84.0 7.1%

3 4.0 8.0 28.0 40.0 0.0 80.0 5.0%

4 1.5 8.0 28.0 40.0 0.0 77.5 1.9%

5 1.2 8.0 28.0 40.0 0.0 77.2 1.6%

6 1.0 8.0 28.0 40.0 0.0 77.0 1.3%

7 0.0 8.0 28.0 40.0 0.0 76.0 0.0%

8 0.0 8.0 28.0 40.0 10.0 86.0 0.0%

Latex solvent base

9 6.0 10.0 30.0 40.0 0.0 86.0 7.0%

10 6.0 8.0 30.0 40.0 0.0 84.0 7.1%

11 4.0 8.0 28.0 40.0 0.0 80.0 5.0%

12 1.5 8.0 28.0 40.0 0.0 77.5 1.9%

13 1.2 8.0 28.0 40.0 0.0 77.2 1.6%

14 1.0 8.0 28.0 40.0 0.0 77.0 1.3%

15 0.0 8.0 28.0 40.0 0.0 76.0 0.0%

16 0.0 8.0 28.0 40.0 10.0 86.0 0.0% Water base wax binder

6.0 10.0 30.0 40.0 0.0 86.0 7.0%

6.0 8.0 30.0 40.0 0.0 84.0 7.1%

4.0 8.0 28.0 40.0 0.0 80.0 5.0%

1.5 8.0 28.0 40.0 0.0 77.5 1.9%

1.2 8.0 28.0 40.0 0.0 . 77,2- 1.6%

1.0 8.0 28.0 40.0 0.0 77.0 1.3%

0.0 8.0 28.0 40.0 0.0 76.0 0.0%

0.0 8.0 28.0 40.0 10.0 86.0 0.0%

Solvent base wax

Dinαer

6.0 10.0 30.0 40.0 0.0 86.0 7.0%

6.0 8.0 30.0 40.0 0.0 84.0 7.1%

4.0 8.0 28.0 40.0 0.0 80.0 5.0%

1.5 8.0 28.0 40.0 0.0 77.5 1.9%

1.2 8.0 28.0 40.0 0.0 77.2 1.6%

1.0 8.0 28.0 40.0 0.0 77.0 1.3%

0.0 8.0 28.0 40.0 0.0 76.0 0.0%

0.0 8.0 28.0 40.0 10.0 86.0 0.0%

Solvent base vinyl

K Uιilntl_<ur1CtI*

6.0 10.0 30.0 40.0 0.0 86.0 7.0%

6.0 8.0 30.0 40.0 0.0 84.0 7.1%

4.0 8.0 28.0 40.0 0.0 80.0 5.0%

1.5 8.0 28.0 40.0 0.0 77.5 1.9%

1.2 8.0 28.0 40.0 0.0 77.2 1.6%

1.0 8.0 28.0 40.0 0.0 77.0 1.3% 9 0.0 8.0 28.0 40.0 0.0 76.0 0.0% 0 0.0 8.0 28.0 40.0 10.0 86.0 0.0%

The moulding mixtures of examples 1 to 40 were used to make animal plugs according to the moulding process of the present invention. The animal plugs were of good quality and suitable for use in the method of slaughtering animals according to the present invention. Further moulding mixtures were prepared, analogous with the compositions of examples 1 to 40, except that the sugar cane pulp added as a source of fibre* was replaced with fibre chosen from the group comprising wheat stalks, tea leaves, rice stalks, rice husks mixed with rice stalks, corn cobs including the leaves and the carbonaceous residue of burnt coconut shells.

The moulding mixtures comprising each of the listed sources of fibre were used to make animal plugs according to the moulding process of the present invention. The animal plugs comprising each different type of fibre were compared with the aforementioned animal plugs comprising sugar cane pulp. While there were differences in quality of the animal plugs depending on the type of fibre used, this was not significant because of the design of the plugs and all plugs were found acceptable.Of the aforementioned sources of fibre, only rice husks have any inherent starch content. The rest of the listed fibre sources have no inherent starch content and therefore make no contribution to the starch content of the moulding mixture. Accordingly, when rice husks were used to make the moulding mixtures of examples 1 to 40, the proportion of starch present was slightly greater than the quantities listed in the table.

It is noted that for examples comprising a given type of fibre, varying the nature of the binder does not affect the quality of the animal plug producing according to the present invention. However, based on environmental considerations, water soluble binders are preferred to use in the moulding mixture because they are biodegradable, whereas binders soluble in non-aqueous solvents are generally not biodegradable.

Preparation of the Mixture

Individual mixtures were prepared using fibers of wheat stalks or rice stalks or sugar cane pulp or com leavesin combination with com pulp. The mixtures were ground by a grinding machine to a size in the range of from 0.1 mm to 5.0 mm. . The ground fiber was combined with the starch (when used) of tapioca flour, sweet potato flour or com flour thoroughly in a mixer (a container with fan like blade spinning at a speed of 500 to 700 rpm) to form a moulding mixture. Care was taken to ensure that the starch did not form into lumps when the liquid ingredients were added. Any lumps which do form should be broken up because when the water forms steam, such lumps of starch will be cooked and will foam which will cause an air trap or hole in the mould plug. A water soluble adhesive with a latex base is then added together with water and the mixture further stirred until the whole mixture is mixed evenly. The Mould

The mould 20 shown in the drawings has a top mould part 21 and a bottom mould part 22. The top mould part 21 has a valve 23 located in its upper surface 24. The bottom mould part has a cavity 25 to receive mixture 26. When mould 20 is closed, there is a gap 27 of about 1 mm between the top mould part 21 and the bottom mould part 22. Once closed, pressure is applied to. upper surface 24. The valve 23 is operated either manually or automatically via a controller (not shown). Typically, the valve 23 is opened (see Figure 6) when the temperature of the mould 20 is at about 110°C. Once the article 28 has dried, the mould 20 is opened and the article 28 removed. Manufacturing a Plug from the Mixture

In the flow diagram of Figure 1, the process commences at A with pre-heating the mould 20 to 70°C. This heating is only required the first time that the mould 20 is used because in a continuous process the mould 20 would be at about 140°C from forming the last article 28 and is actually cooled to 70°C at B. Once formed the article 28 is removed from the mould 20 at C to be trimmed, sealed and further treated as desired.

Once the mould 20 is brought to about 70°C, the mould 20 is opened (see D of Figure 2) and overfilled with mixture 26 (see E). The mould 20 is intentionally overfilled to ensure that there is sufficient mixture to evenly and completely fill the mould 20. The mould 20 is not left cold because when the mixture 26 is compressed under pressure, the solids in the mixture would be forced and compressed to the bottom of the mould and water would separate from the mixture and be squeezed out through the gap or air vent. If the temperature goes above 100°C, the moisture will turn into steam too quickly and can cause an explosion. However when the mould 20 is hot (70°C to 100°C) and the materials are compressed, a portion of the moisture will transform into vapor and start to look for a space or gap to escape. This action will move the solids in the mixture into all the open spaces in the mould 20 with excess mixture seeping out of the mould 20. This action typically takes 5 to 10 seconds.

The mould 20 is then closed (see F of Figure 2). When closed, there is typically a gap 27 of about 1 mm between the top 21 and bottom 22 parts of the mould through which steam and excess mixture can escape. Once the mould 20 is closed, a pressure of about 4000 PSI is applied to the top of the mould 20 (see G) for about 3 to 10 seconds until excess mixture starts coming out of the gap 27 between the mould parts 21 and 22. The appearance of the excess material indicates that the mixture 26 has spread evenly throughout the mould 20.

The pressure also ensures that the shape of the plug is maintained (that is, there is no foaming),^' and controls the desired density/porosity of the plug.

Upon seeing the mixture stop overflowing out of the mould 20, and while the mixture is still in a mouldable form the pressure is reduced to atmospheric and then increased back to a pressure iη the range of from 500 to 1500 PSI. In the examples we used a pressure of about

1000 PSI. Then the temperature was increased to about 140°C. The pressure is reduced to prevent an explosion due to the water turning into steam too quickly.

At this point, the steam will be rushing out through all openings and the faster the steam can escape, the faster the plug will cure and this reflects the importance of having a valve 23 being operated to let the steam escape. Once the temperature has reached about 110°C, the valve 23 is opened to increase the rate of steam escaping (see H).

When it has been observed that the escape of steam has effectively ceased, approximately after one to five minutes at a temperature of 140°C (depending the number of valves), the mould 20 is opened and the substantially dried article 28 removed (see I). As there is overflow, the edge of the plug has to be trimmed using a die cutting machine or manually

(see J).

The plug is then optionally coated with further adhesive by spraying or dipping (see K) and heated at 100°C to 140°C for about 10 seconds to 10 minutes to cure the adhesive. In the example we used temperature of about 130°C for about 8 minutes.

The plug may be further coated with Neoprene to further enhance its resistance to fluids (see

L). Typically about 3 grams of Neoprene is used per square foot of the plug. The coating is applied by spraying or dipping..

Figure 8 shows a top part of a mould (100) comprising mould part (101) and valve (102). Valve (102) sits in a complementarily shaped cavity (103) in mould part (101) and is free to move relative to mould part (101). Cavity (103) end in release hole (104) and valve end

(105) is adapted to seal release hole (104) when the valve (102) in its closed position (not shown). Valve (102) is closed by pressure being applied to top end (106). When valve

(102) is in its open position as shown in Figure 8, steam can escape from the mould (100).

Coating

As mentioned previously, the animal plug of the present invention may be at least partially coated to enhance its resistance to fluids.

Tests have been carried out to measure the absorbency of coated, partially coated and uncoated animal plugs made according to the process of the present invention. Each of the plugs tested were separately inserted into balloons filled with an aqueous acidic solution

(orange juice) and the water contents of the plugs were measured periodically.

Plugs fully coated on all surfaces with water soluble coating showed negligible absorption of water over a 5 hour period. The fully coated plugs were then removed from the neck of the fluid filled balloon. The plugs were observed to retained their shape without distortion for more than 3 days.

Figures 12 to 15 record the relative water absorption of 4 types of partially coated and uncoated animal plugs of differing shapes, the shape depending on their intended use.

Figures 12a, 13 a, 14b and 15b relate to plugs coated on their internal surface. Figures 12b,

13b, 14a and 15a relate to corresponding uncoated plugs.

It is readily apparent from comparison of the graphs for each of the 4 types of animal plugs that the partially coated animal plugs absorbed less water over a given time period when compared with equivalent uncoated plugs.

When the absorption measurements had been completed, each plug was removed from the neck of its respective balloon. tThe partially coated plugs were observed to retain their shape without distortion for more than 3 days. Distortion was tested by applying moderate finger pressure to each plug. Conversely the uncoated plugs started to distort and lose their shape within 24 hours of removal from their balloons.The word 'comprising' and forms of the word 'comprising' as used in this description and in the claims does not limit the invention claimed to exclude any variants or additions.

Modifications and improvements to the invention will be readily apparent to those skilled in the art. Such modifications and improvements are intended to be within the scope of this invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A moulding mixture for use in moulding a plug for sealing an orifice of a slaughtered animal carcass the mixture including:

(i) 40 to 60 wt% plant fibre pieces optionally combined with about 0 to 2 wt % starch with the plant fibre pieces; and (ii) 10 to 55 wt % water and 3 to 10 wt % one or more water-soluble binding agents or adhesives.

2. A moulding mixture according to claim 1 wherein the length of the plant fibre pieces is in the range of from 1 to 5 mm

3. A moulding mixture according to claim 2 having an adhesives content in the range of

4. A moulding mixture according to claim 3 wherein the adhesives content is about 4.7 wt%.

5. A moulding mixture according to claim 1 wherein the fibre content is in the range from 45 to 55 wt %.

6. A moulding mixture according to claim 5 wherein the fibre content is about 52 wt %. 1. A moulding mixture according to claim 1 wherein the water content is in the range from 40 to 45 wt %.

8. A moulding mixture according to claim 7 wherein the water content is about 43 wt %.

9. A process for manufacturing a plug for sealing an orifice of a slaughtered animal carcass, the process comprising the following steps:

(a) preparing a moulding mixture by:

(i) taking 40 to 60 wt% plant fibre pieces and optionally combining 0 to 2 wt% added starch with the plant fibre pieces; and

(ii) adding thereto 10 to 55 wt % water and 3 to 10 wt % one or more water-soluble binding agents or adhesives;

(b) pouring the mixture into a mould the mould being at a temperature of at least 60°C;

(c) subjecting the mixture in the mould to a temperature in the range of 15 to 60 °C and a pressure in the range from 1000 to 7000 PSI for a period of time such that a portion of the water in the mixture is converted to steam which causes the mixture to fill the mould while remaining in a mouldable state; (d) reducing the pressure so that steam continues to form within the mould without causing an explosion whilst maintaining the mixture in a mouldable state;

(e) increasing the temperature and pressure to a temperature in the range from 100 to 300°C and a pressure in the range of 500 to 1500 PSI ;

(f) removing the steam or allowing the steam to escape until the moulded plug is substantially dry;

(g) removing the substantially dried and moulded plug from the-mould;

10. A process according to claim 9 further comprising the steps of:

(h) at least partially coating the moulded plug with one or more binding agents or adhesives; and (i) heating the coated moulded plug to substantially dry and cure the coating.

11. A process according to claim 10 further comprising the step of trimming the plug from step (h) prior to coating the plug in step (i).

12 A process according to claim 9 further comprising a step (j) of treating the plug from step (g) with a body fluid resistance material.

13 A process according to claim 12 wherein the body fluid resistance material is applied only to that portion of the plug which is to contact the tissue surrounding the orifice.

14 A process according to claim 12 wherein the plug is hollow and the body fluid resistance material is applied to the internal surface of the hollow plug.

15 A process according to claim 9 wherein the length of the plant fibre pieces in the moulding mixture is in the range of from 1 to 5 mm

16 A process according to claim 9 wherein the adhesives content of the moulding mixture is in the range of from 2 to 5 wt %.

17 A process according to claim 9 wherein the fibre content of the moulding mixture is in the range from 45 to 55 wt %.

18 A process according to claim 17 wherein the fibre content of the moulding mixture is about 52 wt%.

19 A process according to claim 9 wherein the water content of the moulding mixture is in the range from 40 to 45 wt %.

20 A process according to claim 9 wherein latex-based adhesives are used in the moulding mixture. 21 A process according to claim 20 wherein the latex-based adhesive used in the moulding mixture is Neoprene.

22 A process according to claim 9 wherein step (a) occurs at a temperature below about 25°C.

23 A process according to claim 9 wherein the pressure applied within the mould in step (c) is about 4000 PSI.

24 A process according to claim 9 wherein the period of time in step (c) is in the range of from 3 to K) seconds.

25 A process according to claim 9 wherein the reduced pressure in step (d) is in the range from 500 to 1500 PSI.

26 A process according to claim 9 wherein the increased temperature in step (d) is about 140°C.

27 A process according to claim 10 wherein the heating in step (h) occurs for a period of time in the range of from 10 seconds to 10 minutes at a temperature in the range of from lOO°C to l80°C.

28. A plug for sealing an orifice of a slaughtered animal carcass the plug being formed from a moulding mixture including:

(i) 40 to 60 wt% plant fibre pieces and optionally combining 0 to 2 wt% added starch with the plant fibre pieces; and (ii) 10 to 55 wt % water and 3 to 10 wt % one or more water-soluble binding agents or adhesives.

29. A plug formed from a moulding mixture according to claim 28 wherein the length of the plant fibre pieces is in the range of from 1 to 5 mm

30. A plug formed from a moulding mixture according claim 28 having adhesives content is in the range of from 2 to 5 wt %.

31. A plug formed from a moulding mixture according to claim 29 wherein the adhesives content is about 4.7 wt %.

32. A plug formed from a moulding mixture according to claim 28 wherein the fibre content is in the range from 45 to 55 wt %.

33. A plug formed from a moulding mixture according to claim 29 wherein the fibre content is about 52 wt %.

34. A plug formed from a moulding mixture according to claim 28 wherein the water content is in the range from 40 to 45 wt %.

35. A plug formed from a moulding mixture according to claim 29 wherein the water content is about 43 wt %.

36. A plug for sealing an orifice of a slaughtered animal carcass, the plug being formed by a moulding process having the following steps:

(a) preparing a moulding mixture by:

(i) taking 40 to 60 wt% plant fibre pieces and optionally combining 0 to 2 wt% added starch with the plant fibre pieces; and

(ii) - adding thereto 10 to 55 wt % water and 3*to 10 wt %-one or more water-soluble binding agents or adhesives;

(b) ^' pouring the mixture into a mould the mould being at a temperature of at least

60°C;

(c) subjecting the mixture in the mould to a temperature in the range of 15 to 60 °C and a pressure in the range from 1000 to 7000 PSI for a period of time such that a portion of the water in the mixture is converted to steam which causes the mixture to fill the mould while remaining in a mouldable state;

(d) reducing the pressure so that steam continues to form within the mould without causing an explosion whilst maintaining the mixture in a mouldable state;

(e) increasing the temperature and pressure to a temperature in the range from 100 to 300°C and a pressure in the range of 500 to 1500 PSI ;

(f) removing the steam or allowing the steam to escape until the plug product is substantially dry;

(g) removing the substantially dried and moulded plug from the mould;

37. A plug according to claim 36 wherein the moulding process has the following additional steps:

(h) at least partially coating the plug with one or more binding agents or adhesives; and (i) heating the coated moulded plug to substantially dry and cure the coating.

38. A plug formed according to claim 37 wherein the moulding process further comprises the step of trimming the plug from step (g) prior to coating the plug in step (h).

39. A plug according to claim 36 wherein the moulding process further comprises the step of (j) of treating the plug from step (g) with a body fluid resistance material.

40. A plug according to claim 39 wherein the body fluid resistance material is applied only to that portion of the plug which is to contact the tissue surrounding the orifice.

41. A plug according to claim 39 wherein the plug is hollow and the body fluid resistance material is applied to the internal surface of the hollow plug.

42. A plug formed according to claim 36 wherein step (a) of the moulding process occurs at a temperature below about 25°C.

43. A plug according to claim 36 wherein the pressure applied within the mould in step (c) is about 4000 PSI.

44. A plug according to claim 36 wherein the period of time in step (c) is in the range of frbm"3 to 10 seconds.

45. A plug according to claim 36 wherein the reduced pressure in step (d) is in the range from 500 to 1500 PSI.

46. A plug according to claim 44 wherein the increased temperature in step (d) is about 140°C.

47. A plug according to claim 36 wherein the heating in step (h) occurs for a period of time in the range of from 10 seconds to 10 minutes at a temperature in the range of from l00°C to 180°C.

48. A plug according to claim 36 which includes a cap which is generally bell shaped with a handle extending from within the cap.

49. A method for removing the viscera from the carcass of a slaughtered animal including the steps of:

(a) inserting a plug in accordance with claim 28 into one or more orifices of the carcass to substantially seal the orifice against leakage of body fluids therefrom

(b) severing the viscera from the carcass by cutting the tissue surrounding the orifice; and

(c) removing from the carcass the viscera with the plug sealingly engaged thereto.

50. A method according to claim 49 wherein the plug is inserted into an orifice of the slaughtered animal after the orifice has been severed from the carcass.

51. A method for removing the viscera from the carcass of a slaughtered animal including the steps of: (a) inserting a plug into one or more orifices of the carcass to substantially seal the orifice against leakage of body fluids therefrom

(b) severing the viscera from the carcass by cutting the tissue surrounding the orifice; and

(c) removing from the carcass the viscera with the plug sealingly engaged thereto, wherein at least the plug is formed by a process according to claim 9. 52. A method for removing the viscera from the carcass of a slaughtered animal including the steps of:

(a) ^' inserting a plug into one or more orifices of the carcass to substantially seal the orifice against leakage of body fluids therefrom

(b) severing the viscera from the carcass by cutting the tissue surrounding the orifice; and

(d) removing from the carcass the viscera with the plug sealingly engaged thereto, wherein the plug is formed by a process according to claim 14.