The presently used processes for treating animal hides so as to produce leather or pelts or to retrieve wool in the fell mongering process involve treating the hides with chemicals in a fluid, particularly a liquid. The chemicals used may include depilitants for de-wooling or de-hairing, various acids and other fluids for tanning or dyeing purposes. The conventional method of treating hides is to immerse the hides in a vessel containing a volume of liquid with the active chemicals in the liquid. The hides are left immersed in the liquid in the vessel for substantial periods of time, such as up to thirty hours in tanning of hides. The liquids in the vessel may be agitated to accelerate the penetration of the liquids into the hides.

The batch nature of the processing together with the treatment times needed make the treatment of hides an uneconomic proposition for most abattoirs where the green hides are recovered from freshly slaughtered animals. Frequently the green hides are simply salted and/or dried and exported or conveyed to remote tanning and fell mongering works with low monetary return to the abattoirs.

The batch process results in large volumes of the treatment liquids being inefficiently used and the spent liquids present a substantial pollution problem if they are not extensively processed before discharge.

It is an object of the present invention to provide a process and apparatus for treating hides which enables very effective and relatively rapid treatment of hides with treatment fluids.

It is a further and preferred object of the present invention to provide a process and apparatus for treatment of hides with treatment fluids which can be economically used to process relatively small numbers of hides, e.g. at or in the vicinity of relatively small abattoirs.

It is a further preferred object of the present invention to provide a process and apparatus for treatment of hides with treatment fluids and which enables the substantially continuous processing of individual hides. According to the present invention there is provided a process for treating a hide with a fluid, the process comprising the steps of: stretching a portion of the hide so as to extend the hide in at least one dimension; and, while the hide is in a stretched condition, applying a treatment fluid to the portion of hide so that the fluid penetrates into the hide.

Preferably the step of stretching the portion of hide comprises stretching in two orthogonal directions so as to increase the surface area of the portion of hide. The stretching of the hide is preferably sufficient to open the hide structure which has been found to promote penetration of the fluid into the hide as a result of the opening of the hide structure.

The step of stretching the portion of hide preferably comprises stretching by at least three percent, more advantageously by at least five percent, and most advantageously by at least ten percent, but preferably by less than twenty five percent, and most preferably by less than twenty percent.

The step of stretching the portion of hide may comprise feeding the portion of hide from an upstream pair of driven nip rollers to a downstream pair of driven nip rollers spaced from the upstream pair and rotating at a greater rotational speed than the upstream pair of driven nip rollers so as to stretch the hide in the general direction of advance of the hide, the step of applying the treatment fluid taking place between the upstream and downstream pairs of rollers. The downstream pair of driven rollers may comprise left and right hand pairs of co-operating rollers, both the left and right hand pairs of rollers being angled at an acute angle to the general line of advance of the hide so that the hide is stretched in a direction transverse to the general direction of advance as it passes through the angled pairs of rollers. In an alternative possible embodiment the step of stretching the portion of hide comprises clamping the hide along clamping lines arranged at an acute angle to a general centre line and subsequently

moving each of the clamping lines towards respective lines at ninety degrees to the centre line so as to thereby stretch the hide in a direction transverse to the centre line.

The step of applying treatment fluid may comprise directing a stream of fluid under pressure into contact with the hide. The fluid may comprise a liquid and the step of directing the stream comprises directing the liquid from beneath the hide so that excess liquid can fall from and be collected beneath the hide. Alternatively the step of applying the treatment liquid may comprise contacting the surface of the hide with a liquid bearing applicator, such as a porous compressible applicator bearing the liquid, the applicator being compressed under pressure against the hide surface so that the liquid held by the applicator is applied to the hide surface.

According to the present invention there is also provided an apparatus for treating a hide with a fluid, the apparatus comprising: stretching means for stretching a portion of the hide so as to extend the hide in at least one dimension; and fluid applying means operative to apply a treatment fluid to the hide when the hide is in the stretched condition so that the fluid penetrates into the hide. In a first possible embodiment of the apparatus the stretching means comprises an upstream set and a downstream set of locating and transferring means operative to locate the hide and to transfer the hide past the locating means, the upstream and downstream sets of locating and transferring means being spaced apart and the downstream set being operative to transfer the hide at a greater speed than the upstream set so that the hide is stretched between the upstream and downstream sets. Preferably the upstream and downstream sets each comprise co-operating nip rollers between which the hide is passed.

The downstream set of nip rollers may comprise a left side pair of nip rollers and a right side pair of nip rollers, the axes of the left and right hand pairs being non-colinear and at least one pair being angled at an acute angle to a general line of advancement of the hide in the upstream direction so as to be effective to stretch the hide transverse to the line of advancement as it passes through the angled rollers. Preferably both the left and right side pairs of nip rollers are arranged at an acute angle to the general line of advancement of the hide. The angled rollers may be arranged at an

angle of between 70° and 87° to the general line of advancement of the hide.

In a second possible embodiment of the apparatus the stretching means comprises at least two clamping means for clamping the hide at spaced points and moving means for moving the clamping means relatively apart so as to stretch the hide. The clamping means may comprise means for clamping the hide at at least two points separated in the general direction of the centre line so that the moving means causes stretching of the hide in the direction of the centre line. The clamping means may comprise means for clamping the hide at multiple points on each of two sides of a general centre line of the hide, the moving means being operative to move the clamping points relatively apart in a direction transverse to the centre line. Some of the multiple points are preferably nearer to the centre line than others and the points nearer to the centre line are relatively moved apart to a lesser degree than the clamping points further from the centre line.

Preferably the multiple clamping points on each side of the centre line lie in a respective general line extending away from the centre line at an acute angle to the general centre line, the clamping means being movable by the moving means so as to increase the angle to the centre line towards 90° and thereby stretch the hide between the clamping points on opposite sides of the centre line. In this embodiment the clamping means comprises upper and lower clamping edges co-operable to clamp and hold the hide between the edges, the edges on the opposite sides ^' of the general centre line defining a shallow V-shape, the moving means being operable to move the clamping edges with a hinging movement so as to cause the shallow V-shape to approach a straight line. The clamping means may comprise a plurality of adjacent spaced generally parallel sets of co-operating upper and lower clamping edges, the fluid applying means being located between adjacent sets of clamping edges.

The apparatus may further include conveying means for conveying the hide into a position between the opposed clamping means. The conveying means preferably comprises a conveyor composed of a plurality of longitudinally extending strands on which the hide is carried, the strands being movable apart laterally during operation

of the stretching means to effect lateral stretching of the hide. In this embodiment, and where the clamping means comprises a lower clamping edge engageable with an undersurface of the hide, the clamping edge preferably has a plurality of notches therein, the strands of the conveyor passing through the notches so as to be movable apart as the angle of the clamping edge to the general longitudinal line of the strands changes from an acute angle towards an angle of 90°.

Possible and preferred features of the present invention will now be described with particular reference to the accompanying drawings. However it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention. In the drawings: Fig. 1 shows a perspective view of the principal components of an apparatus for treating hides according to a first preferred embodiment of the present invention,

Fig. 2 is a simplified plan view of the apparatus of Fig. 1, Fig. 3 is a perspective view of a second apparatus for treatment of hides according to a further preferred embodiment of the present invention, and

Fig. 4 is a simplified plan view of a section of the apparatus shown in Fig. 3.

Referring to Fig. 1, there is illustrated an apparatus for treating a hide 10 with a fluid. The apparatus comprises stretching means 11 for stretching a portion of the hide 10 so as to extend the hide and at least one dimension. Fluid applying means 30 is operative to apply a treatment fluid to the hide 10 when the hide is in the stretched condition so that the fluid penetrates into the hide. The stretching of the hide 10 occurs to an extent sufficient to open the hide structure. This promotes and allows rapid penetration of the fluid into the hide 10 as a result of the opening of the hide structure. The stretching comprises stretching by at least 3% in at least one dimension, preferably by at least 5% and most preferably by at least 10%. It is believed that stretching less that 25% and most preferably less than 20% is desirable.

The apparatus includes an upstream set of locating and

transferring means 12 and a downstream set of locating of transferring means 13 which are operative to locate the hide 10 and to transfer the hide 10 past the locating means 12, 13. The upstream and downstream sets 12, 13 are spaced apart and the downstream set 13 is operative to transfer the hide 10 at a greater speed than the upstream set 12 so that the hide 10 is stretched between the upstream and downstream sets. In the embodiment of Figs. 1 and 2 the upstream and downstream sets 12, 13 comprise co-operating sets of nip rollers 14, 15 respectively between which the hide 10 is passed. The downstream nip rollers 15 are driven at a greater rotational speed than the upstream nip rollers 14. The fluid applying means 30 is located between the upstream and downstream rollers 14, 15. The drive means 33, 34 for the rollers is illustrated schematically in Fig. 2. The downstream set of rollers 15 comprises a left side pair of nip rollers 16, 17 and a right side pair of nip rollers, 18, 19. The axes of the left and right hand pairs, 16, 17 and 18, 19 are non-colinear as best seen in Fig. 2. Both pairs are angled at an acute angle to the general line of advancement 20 of the hide 10 in the upstream direction so as to be effective as to stretch the hide 10 laterally as it passes through the angled rollers. This lateral stretching results from the fact that the left side pair of rollers 16, 17 are tending to draw the hide 10 therethrough in the direction of arrow A while the right side rollers 18, 19 are tending to draw the hide 10 through in the direction of arrow B.

In Figs. 1 and 2 both the upstream set of rollers 14 and the downstream set of rollers 15 comprise left and right side pairs of rollers angled to the line of advancement 20 of the hide 10. The upstream rollers 14 comprise a left side pair of rollers 21, 22 and a right side pair of rollers 23, 24.

The mounting of the rollers and the driving of the rollers may be achieved in any convenient manner. In Fig. 1 there is schematically illustrated a mounting arrangement for the upper rollers 16, 18 of the downstream rollers 15. This mounting arrangement for roller 18 comprises mounting bar 24 to which bearings 25 at the ends of the roller 18 are mounted, the bar 24 in turn being supported on arms 26 which are pivotally mounted at their ends remote

from the bar 24 to a frame 27 of the apparatus. The upper rollers 16, 18 may be capable of being raised and also the pressure being applied between the co-operating upper and lower rollers may be selectively variable by means of the air ram 29, or other convenient vertical movement means. The upper rollers 21, 23 of the upstream set of rollers 14 may be similarly mounted although for clarity this mounting is not shown in Fig. 1. The lower rollers 17, 19, 22, 24 may be mounted directly to other portions (not shown) of the apparatus frame 27. Lower rollers 19, 24 are shown as being driven by electric motors 33, 34 in any convenient manner. The relative speeds of the motors 33, 34 are selectively variable so that the speed differential between the upstream and downstream rollers can be controlled as desired. For example, the downstream rollers may be driven at a rotational speed about 25% higher than the upstream rollers so that, with some degree of slipping of the hide as it passes through the rollers, an elongation of the hide in the general line of advancement 20 greater than 10% and less than 25% is produced. The spacing between the upstream and downstream sets of rollers 14, 15 in the direction 20 may be any convenient distance such as in the order of 50cm. The width of the roller assembly may be, say, 200cm. The angle that the rollers define with the line of advance 20 of the hide 10 may be greater than 60° and less than 90° and preferably between 70° and 85°, e.g. about 80° has been found effective. The angle may be selectively variable to enable operator control of the degree of lateral stretching of the hide 10. The other parameter which will affect the degree of lateral stretching is the pressure applied between the upper and lower rollers since this will control the extent of slipping of the hide. Pressures variable between 200 and 600 kPa may be used. The speed differential between the upstream and downstream sets of rollers affects the degree of longitudinal stretching of the hide.

In the space between the upstream rollers 14 and downstream rollers 15 there is located the fluid applying means 30 which applies fluid in the form of a stream under pressure. The fluid comprises a liquid and the stream is directed into contact with the hide 10 from beneath the hide so that excess liquid can fall from and be collected

beneath the hide 10. The liquid applying means 30 is shown as a manifold 31 having a plurality of nozzles 32 for directing sprays or jets of liquids upwardly, the manifold 31 being supplied from a source of fluid and a pump (not shown) through supply line 31a. An alternative form of liquid supplying means 30 shown in broken line in Fig. 2 comprises a liquid bearing applicator 35 which may be in the form of a porous compressible applicator 35 bearing the treatment liquid. The applicator 35 may be in the form of a roller and may be pressured upwardly against the hide surface so that the liquid held by the applicator 35 as applied to the hide surface. This can make economical use of the treatment fluids. Application of treatment liquid to all parts of the surface, including both sides of the hide surface, is not believed necessary since the stretching of the hide and opening of the hide structure makes the hide porous and the liquid will migrate throughout the hide by capillary action in the manner of liquid migrating through blotting paper.

In a second possible embodiment shown in Figs. 3 and 4, the stretching means 11 comprises clamping means 40, 41 for clamping the hide 10 at spaced points and moving means 42 for moving the clamping means 40, 41 relatively apart to stretch the hide 10. In Fig. 3 the clamping means 40, 41 are separated in the general direction of the centre line 20 of the hide 10 and the moving means 42 separates the clamping means 40, 41 in any convenient manner to cause stretching of the hide 10 in the direction of the centre line 20. The clamping means in Figs. 3 and 4 is also operative to stretch the hide 10 transverse to the centre line 20 and for this purpose comprises means 45, 46 for clamping the hide 10 at multiple points on each of two opposite sides of the centre line 20 of the hide 10, the moving means 42 being operative to move the clamping points relatively apart in a direction transverse to the centre line 20. The clamping means.45, 46 comprise upper and lower clamping edges 45u, 451 and 46u, 461 which can be firstly moved relatively towards each other from the position shown in Fig. 3 to clamp and hold the hide 10 between the edges. The clamping edges clamp the hide 10 at multiple points on each side of the centre line 20, the lines of clamping extending away from the centre line 20 at an acute angle α to the centre line 20 as best seen in Fig. 4. The moving

means 42 is operable to move the clamping means 45, 46 to increase the angle α towards 90° and thereby stretch the hide 10 in a direction transverse to the centre line 20. In particular, as seen in Fig. 4, the edges 45u, 451 and 46u, 461 on opposite sides of the centre line 20 define a shallow V-shape, the moving means 42 being operable to move the clamping edges with a hinging movement in the direction of arrows C and C to cause the shallow V-shape to approach the straight line 49. With this arrangement, the clamping points nearer to the centre line 20 are relatively moved apart to a lesser Q degree than the clamping points further from the centre line 20 so that the stretching of the hide 10 in the lateral direction can be relatively uniform.

In the embodiment of Figs. 3 and 4 the clamping means comprises a plurality of adjacent generally parallel sets of co-operating upper and lower clamping edges 45u, 451, 46u, 461, etc. spaced apart in the direction of the centre line 20. The fluid applying means 30 is located between adjacent sets of clamping edges so that the hide 10 is contacted with the treatment fluid when the moving means 42 operates to stretch the hide 10. The apparatus in Figs. 3 and 4 also includes conveying means 50 for conveying the hide 10, the conveying means comprising a plurality of longitudinally extending strands 51 on which the hide 10 is carried. The strands 51 are movable apart laterally during operation of the stretching means to effect lateral stretching of the hide 10. This is achieved by providing the lower clamping edges 451, 461 with a plurality of notches 52 therein, the strands 51 of the conveyor passing through the notches 52 so as to be movable apart as the angle α of the clamping edges 451, 461 to the general longitudinal line 20 of the strands 51 changes from an acute angle towards an angle of 90°.

In use of the apparatus shown in Figs. 3 and 4, the hide 10 on the conveyor 50 can be advanced to the position between the separated upper and lower clamping edges 45u, 451, etc. and the conveyor 50 can then be stopped and the upper and lower clamping edges 45u, 451, etc. brought together to clamp the hide. Longitudinally spaced sets 40, 41 of clamping means can be moved apart to the desired degree to stretch the hide 10 longitudinally. At the same time the left and

right hand sets 45, 46 of clamping means can be hinged to increase the acute angle α towards 90° to thereby laterally stretch the hide 10. When the hide is in a stretched condition, the liquid can be sprayed into contact with the undersurface of the hide. The apparatus in Figs. 3 and 4 may be utilised with modifications to enable more user control of the degree and location of stretching. For example, in one possible embodiment, clamping edges may be operative to engage only with edge regions of a hide, the clamping edges then being relatively separated to flatten and 0 effect some stretching of the hide at the edges. After this, further clamping edges can be engaged with the hide substantially across the entire width and along the length of the hide, generally as shown in Figs. 3 and 4, and the apparatus operated to stretch across substantially the entire width and along substantially the entire 5 length of the hide.

In the drawings, the fluid applying means 30 has been illustrated as a manifold with nozzles along its length. Greater amounts of liquid may desirably be applied to different parts of the hide. For example, some hides have a greater thickness along the 0 general centre of the back compared to the flanks and therefore a greater volume of liquid may need to be applied along the general central region of a hide. For this purpose the apparatus may include a plurality of manifolds and associated nozzles, some manifolds being relatively short in length and located in regions beneath the hide 5 where more liquid is to be applied. For example in the embodiment of Figs. 3 and 4, in addition to the manifold 31 illustrated, the may be provided one or more further manifolds (not shown) of shorter length but symmetrically extending on opposite sides of the centre line 20 so that more liquid will be applied to the general central region of 30 the hide 10. Also it is possible that the liquid applying means 30 could be movable beneath the hide instead of being in a fixed location as illustrated. For example, particularly in Figs. 3 and 4, a manifold 30 may be mounted on a carriage which can move in the general direction of the centre line 20 beneath the clamping means 35 40, 41, etc. so that the hide is stationary and held in a stretched condition while liquid is sprayed along the length of the hide from beneath.

In the preferred embodiments liquid is sprayed onto the undersurface of the hide, but is is possible to spray the upper side or both sides. The hide may be arranged in a generally vertical plane during stretching and application of liquid so that excess liquid runs off the bottom edge.

It has been found that depilitant liquids can be effectively applied to only the side of the hide having hair or wool, whereas in the past it was not believed possible to apply depilitants from that

10 side of the hide only because the hair or wool would prevent or retard the liquid reaching the follicles. However the spreading opens the spaces between the hair or wool allowing the liquid to be sprayed so as to easily reach the follicles and start reacting quickly. This enables a de-hairing operation to be carried out a , r short time after application of the liquid and the hide can be scraped, to remove the hair or wool while relatively dry compared to a saturated hide resulting from soaking or application of liquids to the inside of the hide.

Other apparatus for stretching the hide could be used according

20 to the invention. For example, the hide could be stretched by clamping at its edges and the clamping means moved apart, although this apparatus may not be so adaptable to different sizes of hides as the apparatus illustrated. Another apparatus possibly usable for stretching a hide could comprise double helical rollers having O helical formations of opposite hand on each side of a centre of the rollers so that the skin is stretched laterally by the action of the roller as it passes through, preferably with some restraint on the hide so that there is slipping of the hide and the movement of the helical formations across the hide surface promotes lateral 0 stretching.

The hide treatment time using the present invention can be reduced substantially. The time that the hide is exposed directly to the application of treatment fluid may be less than one minute, but this is variable according to the particular conditions, e.g. hide 5 type (e.g. merino skins are heavily wrinkled and may need longer exposure times for sufficient liquid to be applied) , concentration of chemicals being applied, degree of stretching which can affect speed

of liquid penetration, type of treatment being carried out (de-hairing, tanning, dyeing, etc.). The hide can be stored at a waiting station where the chemical action of the fluids on the hide takes place, e.g. for a time up to two hours. The hide can then be further treated e.g. by removing wool or hair, or washing or neutralising of the chemicals, etc.

The entire treatment of the hide from being a green hide freshly obtained from abattoirs to a de-haired and tanned hide can be in the order of a few hours.

Hides can be processed on a substantially continuous basis. In the embodiment of Figs. 1 and 2, hides can be joined end to end, e.g. by stapling, to form a continuous elongated "sheet" of hides which can be fed continuously through the rollers. In Figs. 3 and 4, individual hides can be laid on the conveyor and fed to the apparatus one at a time on a continuous basis.

The preferred process and apparatus of the present invention enables efficient use of the treatment chemicals with a potentially significant reduction of the pollution caused by discharged liquids in the known hide treatment processes.

It is to be understood that various alterations, modifications and/or additions ma ^{^} be made to the features of the possible and preferred embodiment(s) of the invention as herein described without departing from the spirit and scope of the invention.