PRIORITY DOCUMENTS

[0001] The present application claims priority from Australian Provisional Patent Application No 201 1905054 entitled "CLEANING MATERIAL" and filed on 5 December 2011. The content of this application is hereby incorporated by reference in their entirety.

TECHNICAL FIELD

[0002] The present invention relates to the cleaning of grinding machines. In a particular form, the present invention relates to the cleaning of grinders for foodstuffs and in one example the cleaning of coffee bean grinders.

BACKGROUND

[0003] A by-product of grinding foodstuffs such as pepper, spices and coffee beans is that a residual amount of the foodstuff being ground can remain on the grinding surfaces. This effect can be exacerbated where the foodstuff contains a proportion of oil resulting in a resinous material being deposited on the grinding surfaces. This residual material if it is not cleaned from the grinding surfaces can go off or rancid which will then affect the taste of any subsequent foodstuff that is being ground. Even where the foodstuff is unlikely to go off, the presence of this residual material will contaminate the grinding of a different foodstuff.

[0004] As an example, a spice grinder that first grinds one spice and is then used to grind a different spice without cleaning will often result in contamination of the second spice with residual amounts of the first spice. Where the proportion of oils and fats are high, such as in the case of roasted coffee beans which contain around 13-15% of oil/fat by weight, these oils can adhere directly to the grinding surfaces, in turn binding particulate matter to the surface and reducing the grinder's performance.

[0005] One way to clean the grinding surfaces is to disassemble the grinding machine to allow direct brushing and washing of these surfaces. This is clearly a time consuming task. Taking a coffee bean grinder as an example, this will require almost complete disassembly of the grinder. In the case of super- automatic coffee machines the grinders are difficult to access. Furthermore, as most grinders including coffee grinders are electrically powered, liquid cannot be introduced into the grinder as a cleaning aid. In any event, even if liquid was able to be introduced there is then the difficulty of drying the grinder components.

[0006] One attempt to address this problem has been to introduce a material in the grinder which when ground functions to clean the grinding surfaces before exiting the grinder. Some examples of materials that have been employed in this manner include naturally occurring organic substances such as rice or bulgur wheat to artificially produced products again typically based on organic substances but in either powder or tabletised form. However, these cleaning materials have been found to each have their own disadvantages. Referring now to Figures 1 to 5, there is shown a series of diagrams relating to the grinding of coffee beans by a grinder which will aid in the discussion of these disadvantages.

[0007] Figure 1 depicts a top view of an upper circular burr 100 incorporating a grinding surface 1 10 and central circular aperture 120. The grinding surface 110 in this example comprises three separate regions moving outwardly from central circular aperture 120 including a first coarse grinding region 1 1 1, a second intermediate region 112 and a third fine grinding region 113 located on the periphery of burr 100. Figures 2 and 3 depict sectional views of a grinder 200 formed of an upper circular burr 100A of the type illustrated in Figure 1 and a lower circular burr 100B which differs only from upper circular burr l OOA in that it does not include a central aperture.

[0008] As can be seen in this sectional view, the grinding surfaces 110A, 1 10B of each circular burr 100A, 100B form a concave tapered region which when opposed to each other form a grinding chamber 210 whose vertical dimension reduces moving towards the edge of the grinder 200 to leave a peripheral gap 220 between each burr 1 1 OA, 1 10B. As can be seen in Figure 3, gap 220 may be changed by varying the height of upper burr 100A with respect to lower burr 100B. In this example, lower burr 100B is configured to rotate rapidly as indicated by the arrows while upper burr 100A remains stationary.

[0009] In operation, and as depicted in Figures 4 and 5, coffee beans 300 are introduced into the grinding chamber 210 of grinder 200 through central aperture 120 of upper burr 100 A and travel outwardly to the peripheral edge of upper and lower burrs 100A, 100B via the centrifugal force generated as result of spinning lower burr 100B. As coffee beans 300 move outwardly in the grinding region they meet the initial opposed coarse grinding regions 111 of the upper and lower burrs 110A, HOB where the coffee beans are first broken 310 up to be then ground progressively in turn by the intermediate and fine grinding region 112, 1 13 resulting in fine ground coffee 320. The final coarseness of the ground coffee is determined by the size of gap 220 with a reducing gap size resulting in a finer or more complete grinding of the coffee bean. In this manner, by varying gap 220 the grinder 200 may be configured to deliver ground coffee of varying coarseness.

[0010] As referred to earlier, a number of cleaning materials have been used in an attempt to clean the grinding surfaces of a grinder and in particular a coffee grinder 200 such as depicted here, In the case of materials in the form of powder or crystals these are.found to simply pass through the grinding chamber 210 without engaging the entirety of the grinding surfaces 1 10 in the process producing diist as a waste by product. Similarly, the introduction of raw organic material such as rice or bulgur wheat fails to clean the entirety of the grinding surfaces due to its small size. In addition, uncooked and partially cooked rice is very hard and can cause the grinder to seize during the cleaning process. [001 1] When the cleaner material is in the form of a tablet it crushes substantially to a powder at the point where the tablet dimension equals the gap between the grinding surfaces 1 10. As a result, the tablet remnants move towards the outer edge of the grinding surface without adequately cleaning the intermediate regions between where the tablet was initially crushed and the edge region. Where the organic material for the. tablet employs wheat as a key ingredient then this can introduce gluten into the cleaning process leading to contamination of the grinder chamber 210 or the generation of gluten dust generally. This may pose a risk to users who have severe gluten intolerance such as those who suffer from coeliac disease.

[0012] There is therefore a need for a cleaning material for cleaning the grinding surfaces of a grinding machine that is food safe and convenient to use and/or which provides the consumer with a commercial alternative to products on the market. ¹

SUMMARY

[0013] In a first aspect the present invention accordingly provides a method for forming a cleaning material for cleaning a grinder, including:

forming pellets varying in size from a pelletisable material, wherein the size range of the formed pellets is configured to provide a cleaning action to the grinder in the course of the pellets being ground by the grinder.

[0014] In another form, the pelletisable material is a food safe material. [0015] In another form, the food safe material is an organic material.

[0016] In another form, the organic material is a gluten free material. [0017] In another form, the method includes assessing the fat or oil content of the pelletisable material.

[0018] In another form, if the fat or oil content of the pelletisable material or formed pellets is greater than 10 % then the method further includes extracting oil/fat from the pelletisable material and or the formed pellets.

[0019] In another form, the final fat or oil content of the formed pellets is reduced to a range between 10 % to 5 %.

[0020] In another form, the final fat or oil content of the formed pellets is reduced below 5 %. [0021 ] In another form, if the moisture content of the formed pellets is greater than 10 %, then the method further includes reducing the moisture content of the formed pellets.

[0022] In another form, the final moisture content of the pellets is reduced to a range between 10 % to 5 %.

[0023] In another form, the final moisture content of the pellets is reduced below 5 %.

[0024] In another form, the gluten free material is a combination of rice germ or bran.

[0025] In another form, the gluten free material is either rice germ or bran.

[0026] In another form, the gluten free material is comprised of rice hulls or husks.

[0027] In another form, the gluten free material is comprised of rice stalks.

[0028] In another form, the pellets are substantially cylindrical having a substantially constant diameter and varying in length.

[0029] In another form, the pellets have a substantially constant diameter of 5 mm.

[0030] In another form, the pellets vary in length between 2 mm and 15 mm.

[0031] In another form, the pellets are substantially cylindrical varying in diameter and having a substantially constant length.

[0032] In another form, the pellets are substantially cylindrical and vary in both diameter and length. [0033] In another form, the grinder is a coffee bean grinder.

[0034] In a second aspect the present invention accordingly provides a cleaning material in the form of pellets produced in accordance with the first aspect of the present invention.

[0035] In a third aspect the present invention accordingly provides a method for cleaning a grinder, the method including:

introducing a predetermined amount of pellets formed as a result of the method in accordance with the first aspect of the present invention; and

grinding the predetermined amount of pellets.

[0036] In another form, the grinder is a coffee grinder and the predetermined amount is 50 ml to 100 ml. BRIEF DESCRIPTION OF DRAWINGS

[0037] Illustrative embodiments of the present invention will be discussed with reference to the accompanying drawings wherein:

[0038] Figure 1 is a top view of a circular burr for grinding coffee beans depicting the grinding surfaces;

[0039] Figure 2 is a figurative sectional view of a grinder for grinding coffee beans including the circular burr illustrated in Figure 1 ;

[0040] Figure 3 is a figurative sectional view of the grinder illustrated in Figure 2 where the gap between the upper and lower burrs is reduced to reduce the size of the ground coffee beans;

[0041] Figure 4 is a figurative sectional view of the grinder illustrated in Figure 2 depicting the introduction of coffee beans into the grinding chamber;

[0042] Figure 5 is a figurative sectional view of the grinder illustrated in Figure 3 depicting the progressive grinding of the coffee beans to a smaller size as they move to the periphery of the grinder; and

[0043] Figure 6 is a flowchart view of a method for forming a cleaning material for a grinder in accordance with an illustrative embodiment of the present invention.

[0044] In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings.

DESCRIPTION OF EMBODIMENTS

[0045] The following description contains specific information pertaining to the implementation of the present invention. One skilled in the art will recognize that the present invention may be implemented in a manner different from that specifically discussed in the present application.

[0046] Referring now to Figure 6, there is shown a flowchart view of a method 600 for forming a cleaning material according to an illustrative embodiment of the present invention. In this illustrative embodiment, the grinder that is being sought to be cleaned is a coffee grinder for grinding coffee beans but as would be appreciated by those of ordinary skill in the art the present invention may be applied to other types of grinders consistent with the principles described in this document.

[0047] At step 620 a pelletisable material 610 is formed into pellets of varying size 630 where the size range of the formed pellets provides a cleaning action to the grinder in the course of the pellets being ground by the grinder. In one illustrative embodiment, the pelletisable material is a food safe material and in a further embodiment the food safe material is an organic gluten free material in the form of non-grain rice matter or by-products. In a further embodiment, the non-grain rice matter is a combination of rice germ and bran. In this non-limiting example, the rice germ and bran is obtained by polishing the raw rice material. In another embodiment, the rice germ and bran may be further refined into the germ and bran components and the pelletisable material based on either one of these components.

[0048] In one illustrative embodiment, the forming of pellets involves the following steps

• processing if required the pelletisable material into smaller pieces which can then be more easily managed;

• sterilising the pelletisable material to kill micro-organisms by in one embodiment heating the pelletisable material (e.g. 120 °C for one hour for a rice germ and bran combination);

• milling the pelletisable material to a particle size range as determined in part by the size of the resulting pellets (e.g. between 4-8 mm);

• conditioning the pelletisable material With steam to soften it resulting in improved quality of pellet formation;

• pelleting with a pellet machine;

• cooling of the warm plasticised pellets produced by the pellet machine; and

• sieving the pellets to remove any under or oversized pellets and fines.

[0049] As would be appreciated by those of ordinary skill in the art, all of the above steps may not be necessary and will depend on the original pelletisable material being sought to be processed into a cleaning material.

[0050] As shown at optional step 650, an assessment may be made of the oil/fat content of the pel lets or pelletisable material and in this embodiment where the pelletisable material is a combination rice germ and bran and the oil/fat content is approximately greater than 10 % then a further step of oil/fat extraction may be undertaken. An example oil extraction process applicable to a combination of rice germ and bran is the use of n-hexane or other appropriate solvent which is mixed with the pelletisable material and then separated by either filtration or centrifuging to retain the defatted combination of rice and germ bran. The oil extraction process may also be undertaken wholly or partially after pelletisation has occurred. In one embodiment, extraction is carried out to reduce the final oil/fat content of the pellets between 10 % and 5 % and in another embodiment to below 5 %. Depending on the mode of oil extraction further drying of the pelletisable material or pellets may be required to drive off excess solvents after the defatting process.

[0051] In another embodiment, and as shown at optional step 640, an assessment is made of the moisture content of the formed pellets and where the moisture content is above 10 % drying processes can be introduced to reduce the final moisture content of the pellets to between 10 % and 5 % and in another embodiment to below 5 %.

[0052] Pellets 630 are formed by a pellet machine. In one embodiment, pellet machine is based on an inner mixing chamber residing within an outer annular chamber where steam is introduced as referred to above to facilitate the pelletisation process. The pelletisable material is extruded through an annular die lying between the mixing chamber and the outer chamber by the action of rollers that press the pelletisable material through the die. Located on the outside of the annular die is a plurality of pellet cutting knives which cut the material extruded through the die into individual pellets.

[0053] The die may be configured to extrude pellets of either constant or varying diameter as the case may be. One example of a pellet machine of this type is manufactured by the California Pellet Mill company of Indiana, USA. This is simply one example of a pellet machine and other configurations exist such as those based on an augur arrangement forcing pelletisable material through a die where a guillotine arrangement then slices or cuts extruded pellets from the die.

[0054] As a result of the above process the resultant pellets are configured to have a moisture content of approximately 9 % and an oil content of approximately 6 %. In this illustrative embodiment based on rice bran, the size range found to effectively clean a coffee grinder includes cylindrical pellets of

approximately 5 mm in diameter and varying in length between 2 mm to 15 mm. It has been found that this configuration provides a cleaning material that effectively cleans the entire grinding surface when used in the coffee bean grinder.

[0055] In other embodiments, the cylindrical pellets may be of a diameter of approximately 4 mm or

6 mm and the cleaning material may consist of cylindrical pellets of the same diameter but varying length or cylindrical pellets of differing diameter and the same length or of both varying length and diameter. As would be appreciated by those or ordinary skill in the art the cleaning material could consists of pellets of differing sectional profile.

[0056] In another illustrative embodiment, the pelletisable material is based on the rice stalks. Unlike rice bran, this material is originally low in oil/fat content (i.e. < 2 %) and does not require any oil extraction as a separate step. Again cylindrical pellets of approximately 5 mm in diameter and varying in length between 2 mm to 15 mm have been found to provide a cleaning material that effectively cleans the entire grinding surface when used in a coffee bean grinder. [0057] In order to clean a coffee grinder, a predetermined amount of pellets are introduced and then ground. The amount may vary depending on the size and frequency of cleaning but the applicant has found that a predetermined amount of between 50 ml to 100 ml of pellets is sufficient.

[0058] In another embodiment, the pelletisable material is based on rice hulls or husks. In yet another illustrative embodiment, a mixture of rice bran, stalks and husks or hulls may be utilised.

[0059] As would be appreciated by those of ordinary skill in the art, the use of rice based organic materials provides a gluten free cleaning material which may be used in those environments where gluten intolerance may be issue. In yet another illustrative embodiment, directed to a gluten free pelletisable material, psyllium husks may be used. Another gluten free material that may be utilised is alfalfa. Should the presence of gluten not be an issue, then other organic based products including, but not limited to, oats, wheat, barley, maize or corn, may be used as the basis for the pelletisable material.

[0060] The applicant has also found that the use of the pelletisation process results in a substantially harder cleaning material being produced as compared to a tablet based material. This is thought to be due to the intrinsically higher pressures used in the pelletisation which may be further facilitated by the introduction of steam during the forming of pellets as compared to standard tableting process. This added hardness increases the effectiveness of the cleaning material as any grinder will have to grind the harder material for a longer duration. In addition, pelletisation is a process which may be scaled more readily than tabletisation which requires individual moulds for each tablet and where manufacturing of large, quantities of small grain-based tablets will have to be performed on high speed machines with accompanying low tablet pressure resulting in very soft tablets.

[0061 ] It will be understood that the term "comprise" and any of its derivatives (e.g. comprises, comprising) as used in this specification is to be taken to be inclusive of features to which it refers, and is not meant to exclude the presence of any additional features unless otherwise stated or implied.

[0062] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

[0063] Throughout the specification and the claims that follow, unless the context requires otherwise, the words "comprise" and "include" and variations such as "comprising" and "including" will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers.

[0064] It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the invention is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.