GB2033204A

GB2033204A - Removing Surface Fibres from Animals

Info

Publication number: GB2033204A
Application number: GB7934831A
Authority: GB
Original assignee: Australian Wool Corp
Current assignee: Australian Wool Corp
Priority date: 1978-10-06
Filing date: 1979-10-08
Publication date: 1980-05-21
Also published as: AU526898B2; NZ191768A; FR2437913A1; GB2033204B; FR2437913B1; AU5148479A

Abstract

Surface fibres are removed from live animals, carcasses or hides, and particularly wool is removed from sheep, by a broad fibre impacting member 9 having a plurality of spaced shallow indentations which is rotated so as to strike successive groups of fibres in a direction transverse to the direction of the fibres. The fibre impacting members 9, are connected to rotating blades 1 and 2 which are rotatably driven within a housing 8 having a wool intake opening 12 and a fibre and air discharge opening 13. The blades have means 11 which create air movement within the housing into which the removed fibres are entrained for removal to the discharge opening 13. If desired a separate air stream may be created for the same purpose. The apparatus is particularly suitable for use in the removal of chemically weakened wool from sheep but is equally applicable to the removal of fibres from carcasses and hides. <IMAGE>

Description

SPECIFICATION Removal of Surface Fibres from Sheep and other Animals This invention relates to methods and apparatus for removing the surface fibres which form the coat of wool bearing animals such as sheep and of hair bearing animals such as goats and cattle. The invention also relates to methods and apparatus for removing the surface fibres from carcasses or hides of such animals.

Considerable research has been conducted into the development of economical and practical methods of biochemically or chemically producing a break or a controlled tenderness or weakness in the wool fibres of sheep. Most chemical treatments result in a temporary interruption of follicle activity which produces a weakened zone in most of the fibres. In certain cases, some of the fibres remain unaffected, but these usually represent a small minority of fibres in any one area of the animal's coat. During subsequent growth of the fibres, the weakened zone emerges from the skin and it is preferred that dewoolling take place after a small amount of growth (say 6mm) has occurred.Research has also been conducted into the genetic development of breeds producing naturally weakened fibres and into the weakening of fibres by dietary control or by exposure of the animal to natural conditions such as weather.

Varying degrees of success have been experienced in these researches with the main problem being the controi of the weakening of the fibre to such an extent that the same dewoolling technique can be used for all animals. It has been found difficult to obtain reproducible results in which the weakness in the wool fibre is suitably balanced between substantially weakened or completely broken fibres which are easily removed by various techniques but which suffer serious field losses, often resulting in nude sheep, and insufficiently weakened fibres which are difficult or impossible to remove by known techniques without serious discomfort to the animals.

It has been found that most of the dewooling techniques tested to date are unsuitable for the wide ranges of fibre weaknesses produced by the presently known chemical and other fibre weakening techniques.

Problems have also been encountered in the development of efficient techniques for removing wool and hair from carcasses and hides. Even though the well-being and comfort of the animal is not a consideration in this case, difficulties have been encountered in developing a method which lends itself to an automated dewooling or dehairing operation and which removes the wool or hair without damaging the skin of the carcass or hide.

Many different methods and apparatus for dewoolling sheep having weakened fibres have already been proposed. A considerable amount of research has been conducted into systems based on known feather plucking and animal carcass dehairing apparatus of the type in which rubber fingers extending from a rotating drum are used to frictionally contact the wool and skin of the sheep to place the wool fibres under sufficient tension to cause fracture at the point of weakness. This method has been found to achieve fibre fracture where the weakening of the fibres is adequate, but where the weakening of the fibres is inadequate the tendency is for the fibre to be pulled from the skin of the animal causing serious discomfort.Further discomfort and skin damage is also caused by contact between the fingers and the skin of the sheep and for this reason the method is not altogether satisfactory even for the dewooling or dehairing of carcasses or hides.

Another serious disadvantage of this method is that the frictional contact between the fibres and the rubber fingers removes individual fibres which tend to wrap around the fingers and the drum and tangle together because of the rotary movement of the drum. Furthermore, even if wrap and entanglement can be avoided, the separated individual fibres are difficult to collect and are not suitable for the necessary subsequent processing to which wool must be subjected. It is highly desirable and even essential for the wool fibres to be removed in staples, the larger the better, otherwise great difficulties are experienced in the subsequent processing operations.

Other dewoolling techniques which have been tested include counter-rotating rollers which grip the fibres and pluck them from the sheep (for example, see U.S. Patent No. 3,608,153), and elongate rotating fingers which comb through the fibres in a manner similar to the techique for combing goats' hair disclosed by V. F. Petrov in Ovtsevodstvo. U.S.S.R 1969(11 )(38-39).

Neither of these techniques has been found to successfully remove wool without serious discomfort to the animal. Furthermore, both methods suffer from practical difficulties. In the case of the counter-rotating rollers, it is difficult to ensure that the wool feeds in between the rollers at the proper rate and in the case of the comb arrangement, fibre tangle is likely to result.

It is the object of the present invention to provide a method and apparatus for removing the surface fibres of animals, carcasses and hides. A more specific object is to provide a method and apparatus for removing the surface fibres of animals such as sheep in which fracture of the fibres is achieved for a wide range of fibre weaknesses of the type.produced by chemical, genetic or natural means, and which results in removal of the fibres in staples.

In its broadest aspect, the invention provides a method of removing the surface fibres from animals, carcasses or hides comprising striking successive groups of the fibres with a broad fibre impacting member so that the impacted fibres are removed by impacting forces.

The fibre impacting member preferably has a direction of movement which is transverse to the length of the fibres such that broad fronts of the fibres are successiveiy impacted by the fibre impacting member.

It should be pointed out that the method described above is not suitable for the removal of weakened wool since it does not result in removal of the fibres in staples. However, the method is suitable for the removal of surface fibres from animals, carcasses and hides where it is not important for staple removal to be achieved.

In an aspect of the invention which relates to the dewoolling of sheep having a point of weakness in some or all of their fibres, or sheep carcasses or hides having weakened or unweakened fibres, the method of removing the fibres includes the steps of aggregating adjacent groups of fibres on a region of the sheep's coat, and striking the aggregated groups of fibres with a fibre impacting member whereby the combined action of aggregation and impact achieves fracture of staples of the fibres at their points of weakness and/or at their fibre follicles.

Where the animal has been subjected to chemical treatment, a small minority of the fibres may not be weakend in which case the method of the present invention will cause these fibres to be parted from their fibre follicles at the same time as the weakened fibres are fractured from their remaining fibre roots. Thus, the coat of the animal may be substantially completely removed by the method of the present invention without any unreasonable discomfort to the animal.

The movement of said fibre impacting member may be rotary or reciprocating such that successive regions of the weakened fibres on the animal are repeatedly aggregated and impacted by the said fibre impacting member.

The fractured fibre staples and other individual fibres may be removed from the reigion of impact by various means. For example, where the fibre impacting member rotates, the rotary movement thereof may be sufficient to remove the fractured fibre staples and other individual fibres to another region from which the fibres may be transported to a collection point. Alternatively, the fibre staples may be removed by means of a gas stream passing over said fibres in the region of impact fracture.

As mentioned above, the invention is equally applicable to the removal of unweakened fibres from animal carcasses, the only difference being that most of the fibres are fractured from their fibre follicles or at any naturally occuring zones of weakness.

In another aspect, the invention provides an apparatus for removing the surface fibres from animals, carcasses and hides comprising a broad fibre impacting member, means for moving said fibre impacting member in a manner such that the impact of said fibre impacting member against said fibres causes fracture of said fibres.

Where the fibres have chemically or otherwise introduced weaknesses at specific points along their lengths, fracture will occur at these points.

However, where the fibres are not weakened, such as in the case of an untreated carcass or hide, the fibres will fracture at their fibre follicles.

More specifically, the invention provides an apparatus for dewoolling sheep having a point of weakness in some or all of their fibres, or for dewoolling sheep carcasses or hides having weakened or unweakend fibres, comprising means for aggregating adjacent groups of fibres in a region of the sheep's coat, a broad fibre impacting member, and means for moving said fibre impacting member to strike the aggregated fibres to cause fracture of the fibres in staples.

The means for moving said fibre impacting member may be in the form of any suitable rotary or reciprocating drive and the apparatus preferably includes means for removing the fractured fibre staples and any individual fibres from the region of impact between the fibre impacting member and the fibres.

in a preferred embodiment, the fibre impacting member carries the means for aggregating adjacent groups of the fibres. In one form the fibre aggregating means comprises shallow indentations in the leading surface of the fibre impacting member, which indentations serves to collect the fibres in groups as the impacting member strikes the fibres.

In one preferred embodiment of the invention which is suitable for use either with live sheep having induced weaknesses in their wool fibres or with sheep and other animal carcasses or hides generally, the fibre impacting member is in the form of a bar having a plurality of short closely spaced teeth, said means for moving said fibre impacting member comprising one or more rotary or reciprocating members having a said bar secured to or formed at or near the free ends thereof, said rotary or reciprocating members being connected to means for driving said members at a velocity sufficient to cause impact fracture of the fibres in staples.

In one specific embodiment, the rotary members are in the form of blades secured to or forming part of a central shaft or drum and extending generally radially therefrom with a said bar secured to or forming part of the free end of the or each blade, each said bar having a fibre impacting face which is preferably arranged in a plane generally perpendicular to the direction of travel of said blade.

In one form of bar, the teeth may be between about 0.5 mm and 6 mm in height, although this range of heights is by no means essential.

However, in practical terms, the height of the teeth should not exceed about 10 mm. The bar is preferably formed with scalloped regions between adjacent teeth, for example as shown in Figures 2 and 3, to reduce fibre retentiaon between the teeth and to aggregate and cup the fibres in staples between adjacent teeth. This aggregation and cupping action is believed to assist in the achievement of efficient fracture of the fibres at any points of induced weakness or at the fibre follicles.

The rotating blades preferably have convex leading faces whereby the fractured staples tend to be thrown clear of the blades by the rotary action. In addition, the blades may be formed to induce air flow over the region of impact between the fibres and the fibre impacting member to assist in removing the fractured staples from this zone.

The blades are preferably rotatably mounted in a housing having a wool intake opening arranged forwardly of a vertical plane containing the axis of rotation of said blades, said housing being spaced from the blades forwardly of the wool intake opening to provide a region into which the fractured fibre staples may be thrown by the rotary action of the blades. The base of the housing rearwardly of the intake opening is preferably shaped to receive the contours of the animal's body and the intake opening extends from a position just forward of the lowest point in the path of the blades to prevent direct contact between the blades and the body of the animal.

The housing is also preferably formed with a discharge opening located rearwardly of the rotating blades and the housing has an air scroll shape between the intake opening and the discharge opening to facilitate adequate movement of air and fibre staples through the housing.

It will be appreciated that the above described embodiment represents only one of the many forms in which the present invention may be realised. For example many different forms of rotary and/or reciprocating members may be used to achieve impact fracture of the fibre staples. For example, the fibre impacting means may be formed on or attached to a drum whereby negligible air flow is created on rotation of the device. In this arrangement it may be desirable to provide a separate air or gas flow, for example an air blower delivering an air flow to the wool intake or adjacent thereto, or an air suction source connected to the discharge opening. The air blower or suction source in either of the above cases may for example be connected to a number of dewoolling devices.

The fibre impacting bars may have various tooth configurations and pitches and may be made from any suitable rigid, semi-rigid or reiatively soft material. For example, it may be necessary for the bar to have teeth with a wide pitch for fibres with a high degree of induced weakness, while bars having teeth with a narrow pitch may be necessary for fibres having a low degree of induced weakness. By designing an impacting bar having a combined wide pitch/narrow pitch or some form of intermediate tooth pitch arrangement, it may be possible to allow for most fibre weaknesses.

One presently preferred form of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a side elevation of a prototype apparatus for dewoolling sheep (approximate scale: half size), Figure 2 is a sectional elevation along the line A-A in Figure 1, and Figures 3, 4, 5 and 6 show various impacting bar profiles (approximate scale: full size).

Referring to Figures 1 and 2 of the drawings, the dewoolling apparatus comprises two blade members 1, 2 extending radially from a shaft 3 which is rotatably supported by bearings 4, 5 which are in trun supported by spider members 6, 7 secured to the sides of a housing 8 enclosing the blades 1, 2. Each blade 1, 2 has a rigid metal fibre impacting bar 9 secured to the free edge thereof in alignment with the leading face of each blade and having a plurality of short spaced teeth along its length. in the embodiment shown, the fibre impacting bars 9 are separately formed and secured by means of bolts 10 to the blades 1, 2 although it will be appreciated that the teeth may be formed integrally in the edges of the blades 1, 2.

The blades 1, 2 preferably have a convex leading face to assist in removing the severed fibre staples from the region of severance. Each blade 1, 2 also has a lateral extension blade 11 which are formed with a rake which creates air movement into the housing 8. Another function of the extensions 11 is to prevent fibres from wrapping around the shaft 3.

The housing 8 is formed with a wool intake opening 12 and a fibre and air discharge opening 13. The intake opening 12 extends from a position just forwardly of the lowest point in the travel of the blades 1, 2 to a position spaced from the path of rotation of the blades 1, 2. The housing is formed with an air scroll configuration extending between the intake and discharge openings to ensure that the air flow generated by the blades 1, 2 and the blade extensions 22 moves freely through the housing 8.

The housing 8 is formed with a concave base member 14 which, as best seen in Figure 2, receives the contours of the body of the animal being dewoolled. It will be appreciated that the blades 1, 2 and the toothed impacting bars 9 may be shaped to conform with the configuration of the base member 14 for more efficient dewoolling of the animal.

The shaft 3 is in use connected to the output of a motor drive 1 5 which, in the present prototype, is hand held and drives the blades at between 3,000 and 4,000 rpm. In experiments conducted with the above described prototype operating at 4,000 rpm and using the tooth configuration and height shown in Figures 2 and 3 of the drawings, it was found that impact fracture of adequate fibre staples from a sheep having a majority of its fibres chemically weakened in the manner described above was efficiently achieved. The machine was found to be substantially self clearing with substantially no fibre tangle or wrap-around and it was possible to proceed with dewoolling at a relatively rapid rate.

The blade dimensions and spacing shown were found to be suitable for treated, merino sheep having average wool growth of about 7 cm to 10 cm. Where the sheep has longer wool, it may be necessary to increase the length of the blades to prevent wrap-around.

It is believed that the success of the apparatus in achieveing impact fracture of fibre staples is due mainly to the provision of short fibre aggregating teeth on the bars 9. In experiments leading up to the present invention, it was found that plain blades achieved only individual fibre removal whereas when the toothed bars 9 were fitted to the blades, staple removal resulted.

In the above embodiment, the leading face of bar 9 is approximately perpendicular to the direction of travel of the blades. However the bars may be inclined to achieve improved or different fracturing characteristics.

To assist in clearing the fractured fibre staples from the blades, it may be possible to arrange a series of air nozzles so as to direct an air blast at the trailing edge of the blades whereby any fibres on the blades after fracture will be positively detached by the air blasts.

It will be appreciated from the preceding description that it is not essential that the blades be formed to generate air movement within the housing since this may be achieved by a separate blower connected to the housing near the wool intake opening or by a suitable air suction device connected to the discharge opening. In this situation it may be desirable for the rotary member supporting the toothed impacting bars to create little or no air flow and this may be achieved by securing the bars to the surface of a drum or by forming blades in a neutral paddle configuration. Similarly, instead of a rotary device, reciprocating toothed impacting bar members may be used in conjunction with some form of air removal arrangement.

It will also be appreciated that more than two blade/impact bar member combinations may be used with the possibility of reducing the speed of rotation proportionately.

Any one of the tooth profiles shown in Figures 3 to 6 may be used with the profiles having small tooth pitches being more suitable for fibres having low levels of induced weakness. As mentioned above, it may be possible to design a hybrid tooth profile which is suitable for a wide range of induced fibre weaknesses or it may be necessary to change the toothed bars depending on the induced weakness of the fibres encountered during the dewoolling operation.

Similarly, it may be possible to- make the toothed impacting bars from semi-rigid or quite pliable materials. For example, it is envisaged that it may be possible to form the teeth from a resilient material such that the pitch of the teeth is momentarily reduced at or near the point of impact with the fibres whereby fibre staples are positively gripped by the teeth during the fibre fracturing operation.

In another embodiment of the invention suitable for removal of wool and hair from carcasses and hides, the toothed impacting bars may be removed. In this embodiment individual fibres are removed from the face of fibres impacted by the blades.

Claims

1. A method of removing the surface fibres from live animals, carcasses or hides, comprising striking successive groups of said fibres with a broad fibre impacting member having a direction of movement which is transverse to the length of the fibres, whereby said groups of said fibres are impacted by said fibre impacting member and said impacted fibres are removed by impacting forces.

2. The method of claim 1, further comprising the step of aggregating adjacent regions of each group of fibres immediately prior to striking each said group of fibres with said impacting member.

3. The method of claim 2, wherein said step of aggregating said fibres is achieved by plurality of spaced shallow indentation in the fibre impacting member separated by narrow raised projections which penetrate said groups of fibres and cause said adjacent regions of fibres to aggregate in said indentations.

4. The method according to claim 1, 2 or 3, further comprising the step of collecting said removed fibres from the region in which impact between said fibres and said impacting member occurs by creating a gas stream in said region and into which said fibres are entrained for removal to a remote position.

5. A method of dewoolling sheep having a point of weakness in at least a majority of their fibres, including the steps of aggregating adjacent groups of fibres on a region of the sheep's coat, and striking the aggregated groups of fibres with a fibre impacting member whereby the combined action of aggregation and impact achieves fracture of staples of the fibres at their points of weakness and/or at their fibre follicles.

6. The method of any preceding claim wherein said fibre impacting member is rotated or reciprocated and moved such that successive regions of the fibres are impacted by said fibre impacting member.

7. The method according to claim 5 or 6, further comprising the step of collecting said removed fibres from the region in which impact between said fibres and said impacting member occurs by creating a gas stream in said region and into which said fibres are entrained for removal to a remote position.

8. An apparatus for removing the surface fibres from animals, carcasses and hides comprising a broad fibre impacting member, and means for moving said fibre impacting member in a direction which is transverse to the length of said fibres, such that the impact of said fibre impacting member against said fibres causes fracture of said fibres.

9. The apparatus of claim 8, further comprising means for aggregating adjacent regions of fibres immediately prior to engagement between said impacting member and said fibres.

10. The apparatus of claim 8, wherein said broad fibre impacting member is formed with a plurality of spaced shallow indentations separated by narrow raised projections, said projections operating to penetrate said groups of fibres and cause aggregation of adjacent groups of said fibres in said indentation immediately prior to said impacting member engaging said fibres.

1 1.The apparatus of claim 10, wherein said fibre impacting member is in the form of a bar having a plurality of short closely spaced teeth, said means for moving said fibre impacting member comprising one or more rotary or reciprocating members having a said bar secured to or formed at or near the free ends thereof, said rotary or reciprocating members being connected to means for driving said members at a velocity sufficient to cause fracture of the fibres in staples.

12. The apparatus of claim 1 wherein a plurality of said bars are secured at the periphery of a rotating body. ~~~~~~~~~~~~~~~~

13. The apparatus of claim 8, 9, 10 or 11, further comprising means for creating a gas stream in the region in which impact between said fibres and said impacting member occurs and into which said fibres are entrained for removal to a remote position.

14. The apparatus of any one of claims 8 to 12, wherein the or each said fibre impacting member is mounted on a rotatable member within a housing having a fibre intake located forwardly of a vertical plane containing the axis of rotation of said member(s), said housing having a discharge opening and a path between said openings for a gas stream into which said fibres are entrained for removal to a remote position.

1 5. The apparatus of claim 14, further comprising means on said rotatable member for creating an air stream along said path and into which said fibres are entrained.