BACKGROUND OF INVENTION Skins and hides have been treated to produce Kellatier for centuries, and a typical tanning process generally includes the curing of the green skin or hide by salting or drying prior to shipping to the tannery. At the tannery the cured skin are soaked in water to remove the salt and also any blood and dirt. This soaking may take from hours to seven days depending on the condition of the skins. The flesh is then removed from the inner surface and to loosen the hair or wool the skin immersed in a solution of lime and sodium sulphide from one to up to nine days following which the hair or wool is-removed by a dehairing machine.

Also it is often necessary to pass the skin or hide through a dry cleaning solution to remove the fats and proteins from the skin or hide.

The skins or hides are then soaked in a weak solution of acid and simultaneously most skins are subjected to a baling process. Following this the skins or hides are tanned, either by vegetable tanning which may take several weeks or months, or by chrome tanning which maybe completed in a single day, the tanning involving the immersion of the skins or hides in two different liquors in a tumbling drum.

The leathers can then be lubricated and dyed, with a final drying on stretching frames.

In our previous application PCT/AU97/00262 there is described a process and apparatus for the treatment of skins or hides which includes the selection of a skin or hide, stretching the skin or hide by toggles on a frame to a desired configuration and applying a chamber to the upper side of the skin or hide, sealing the chamber to the skin or hide and applying a pressurised liquor in the chamber so that the liquor penetrates the skin or hide. Means are

provided on the undersurface of the skin or hide to support the distended skin or hide and also to sense the presence of the liquor penetration the skin or hide to provide control of the treatment of the skin or hide.

However the treatment liquor must be applied to the inside of the skin or hide, that is the side opposite to the outer or wool or hair side of the skin or hide.

Thus in the above specification the liquor is applied to the upper side of the skin or hide and the lower side of the skin or hide has the hair or wool attached thereto.

In tanning operations it is necessary for the wool or hair to be removed from the skin or hide, and in the above described process this can only be done when the skin or hide is removed from the toggles and the hair or wool removed before the next tanning process and the skin again attached to the toggles to maintain the stretched condition during the subsequent tanning or other treatment processes by being passed from one treatment station to the next.

Reference is also made to our previous patent application PCT/AU/98/00629 which describes a process and apparatus for the treatment of skins or hides.

The skin or hide is placed on a frame with the flesh side adjacent the frame.

The skin or hide is manually stretched and pinned to pins protruding from the upper surface of the frame. The edges of the skin or hide are then sealed by pressure sealing to the frame at which time treatment liquor under pressure is applied between the skin or hide and the frame to distend and stretch the skin or hide to open the structure of the skin or hide to permit penetration of the treatment liquor into the skin or hide.

However this manual operation of stretching and pinning the skin or hide to the frame is an operation which includes skill and dexterity to ensue that the operator is not stabbed or pierced by a pin.

BRIEF STATEMENT OF THE INVENTION It is an object of this invention to provide a process and apparatus which removes the necessity of retaining the stretched skin or hide by pins until it is sealed to the frame.

Thus there is provided according to the invention a method of treating skins and hides including the steps of providing a grid or mesh supported by a support frame, positioning a green or soaked skin or hide flesh side down onto the grid or mesh such that the grid or mesh holds the skin or hide in an un- stretched or relaxed condition, positioning a sealing frame to seal the hide or skin against the support frame, and supplying a treating liquid under pressure through the grid or mesh to stretch the skin or hide to permit penetration of the treating liquid into the skin or hide.

Also there is provided according to the invention an apparatus for treating skins or hides including a peripheral support frame, a grid or mesh supported by the peripheral frame, a sealing frame adapted engage in sealing relationship with the support frame, means to supply under pressure a treating liquid through the grid or mesh from the side of the grid or mesh opposite to the sealing frame, whereby the grid or mesh holds and locates a skin or soaked hide in position in a relaxed state on the grid or mesh and overlying the support frame until sealed against the support frame by the sealing frame.

The mesh preferably is such that with a woven wire mesh, the wires should be of a dimension and spacing that the green or soaked skin or hide will when in contact therewith or when manually pressed into engagement, the surface of the hide or skin will penetrate slightly into the spaces of the mesh, and due to the plurality of the wires and spacing the skin or hide will be maintained in position until sealed by the mechanical sealing members around the edge of the skin or hide.

BRIEF DESCRIPTION OF THE DRAWINGS In order to more fully describe the invention reference will now be made to the accompanying drawings in which:- Figure 1 is a schematic view of the frame, skin or hide and sealing frame, Figure 2 is a side view of one form of the invention, Figure 3 is a side view of a further form of the invention, Figure 4 is a partial view of the skin or hide prior to sealing,

Figure 5 is a side view of the seals, and Figure 6 is a view of the skin or hide being sealed to the frame.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to Figure 1, the support 1 which for simplicity is illustrated as a frame 1, has a fixed seal 2, to be described in more detail later, generally in the shape of the skin or hide to be treated. The skins or hides are sorted into various sizes and thus the skin or hide will generally be of a size to be treated according to the invention. Across the frame 1 there is provided an open mesh 4 extending to the fixed seal 2. The purpose of the mesh 4 is to support and maintain the skin in position until the edges are sealed by the sealing frame 5 to the frame 1. Preferably the sealing frame in this embodiment is an open frame so that during the process of the invention the skin or hide can stretch under inflation as shown in dotted lines in Figure 2.

The skin or hide 3 is placed on the mesh 4 of the frame and pressed onto the mesh so that the skin is gripped by the mesh. The sealing frame is then lowered and seals the skin to the frame. Although not shown, the sealing frame may be mounted on the frame, for example by a parallel linkage arrangement so that it can be raised and swung away from the frame.

Alternately the sealing frame can be mounted on vertical posts which may be telescopic to enable the sealing frame to be raised and lowered.

A funnel shaped port 6 or collection chamber is provided below the mesh 4 through which treating liquor is supplied under pressure. The skin is thus distended and stretched, the degree of stretch being up to 15% or more. The stretch thus opens the skin and the fibres are thus separated which permits the entry of the treating liquor to penetrate into the skin or hide. The skin or hide maybe fully penetrated within a few minutes or less, compared with the many hours with conventional processes. After treatment the treating liquor is drained through the same opening as used for supplying the pressurized liquor.

Figure 3 illustrated a further embodiment of the invention for the treatment of sheep skins. The skin 7 is placed in position, and a hood 8 having an inlet 9 is then placed over the skin and seals onto the sealing frame 5. While the skin is

stretched with the treatment liquor, a scouring liquid is then passed into the hood to scour the wool. In this way the scouring can take place as part of the treatment process of the skin without having the scouring to be undertaken as a separate process. Also if desired as shown in Figure 3, the treatment liquor can be recirculated by means of a pump, so that there is a continuous supply of treatment liquor, and which circulation assists in removing material obtained from the hide or skin during the treatment process.

Also it is preferred that the treatment liquor be continually passed over the surface of the skin, preferably by a turbulent motion. A baffle or baffles may be positioned adjacent the inlet or a recirculating inlet to create a turbulent flow, and also to prevent direct impingement of the pressurised liquid onto the skin.

These baffles may have holes therethrough to assist in creating the degree of turbulence. Furthermore there may be a plurality of inlet orifices which may be directed to produce a turbulent flow across the surface of the skin.

Figures 4 to 6 show a preferred seal 2 and co-operating seal 11 in the frame 5.

The seal 2 includes a serrated member or blade 12 attached to or clamped in position on the frame 11 by annular members 13. The co-operating seal 11 on the frame 5 includes a resilient ring of rubber or silicon rubber or other resilient material 14 positioned to be above the serrated member 12 in the sealing position. The seal 11 includes a downwardly facing serrated member 15 spaced inwardly of the serrated member 12 so that in the sealing position the skin or hide is deflected around the serrated member 15 ensuring that the skin or hide is securely held by the two co-operating serrated members 12 and 15. It has been found that due to the nature of a wet hide or skin a suitable seal or clamp must be such that it will grip the skin or hide which is under tension due to the pressure under the skin or hide. Thus to ensure that the seal grips the skin or hide, the seal must include members which are rough or serrated so that the gripping member at least partially indents or protrudes into the surface of the skin or hide. As shown a serrated member is satisfactory and preferably the serrated member can be in the form of a continuous band which can be bent as desired to the contour of the skin or hide.

In a further embodiment the frame 5 may be a separate frame not mounted on the frame 1 to which the skin or hide is attached prior to the separate frame being positioned on the frame 1. The frame which is mounted on the frame 1 or a separate pressure applying frame is then lowered and seals on the

separate frame and the frame 1. In this way skins or hides may be attached to a separate frame and then the frame with the skin or hide attached may be removed for removal of the skin or hide from the frame, or for further processing.

Although it is preferred the skins or hides be supported on a mesh, it is to be realized the skins or hides may be supported by a grid like structure having serrated or otherwise shaped surfaces on the top edges of the structure of the grid.

In the treatment of skins or hides, it will be seen that most if not all of the steps necessary for the treatment or tanning of the skins or hides can be carried out in a quick and efficient manner, reducing the time required from days to hours and even minutes for some treatments.

After positioning the skin or hide, the skin or hide can first be treated with a detergent or dry cleaning procedure to remove the fats. By removing the fats the time for the ensuring treatments is greatly reduced due to the fact that the presence of fats hinders the penetration of the treatment liquor. Also the process permits the removal of hair or wool from the skin or hide to be treated to be leather. The dehairing liquor is applied to pressurise the skin or hide, the dehairing liquor thus penetrating the skin or hide to destroy the hair or wool follicles. With the skin or hide in the stretched condition the hair or wool can be removed by brushing or by a vacuum pump. However, if the sheep skin is to be treated with the wool remaining to produce products such as rugs or mats, or items of clothing, the wool is not removed but is scoured as described above.

Thus by sequential addition and removal of liquors with the skin in the stretched condition, the skin or hide can be treated. Also by the process it is possible to have complete control of the time of treatment of each skin or hide.

If desired a cleansing solution of either water or detergent can be applied between each operation of the process to remove the previous liquor and to flush away any matter removed during that step in the process.

The skin or hide can be stretched up to 15% and in order to retain the skin or hide in the stretched condition, the skin or hide is dried while it is in the stretched condition. Additionally a skin or hide on a separate portable frame

may then be positioned on a further frame for the drying operation. Also a further stretching may be applied to the portion of the hide or skin in the area of the seal.

It has been found that with most hides and skins the thickness is greater along the back in the spine area. To produce a hide or skin of uniform thickness, if desired, the skin or hide can be stretched longitudinally along the central area by tensioning the skin or hide longitudinally when being positioned on the mesh.

In some instances the skin or hide maybe positioned with the skin having folds on the hide, the skin or hide being positioned on the mesh and over the seal area, the skin or hide being retained in position by the mesh until the sealing frame is lowered to seal the edges on pressurisation by the treating liquor, the folds are not a detriment, for the infusion will remove the folds and stretch the skin.

Also it is preferred that the treatment liquor be continually passed over the surface of the skin, preferably in turbulent motion, this being more desirable when removing the fats and proteins by a detergent solution. It has been found that the pressure of the liquid under the skin or hide need only be in the order of 1 psi, although higher pressures maybe desirable in some instances.

Also it is within the scope of the invention that the skins or hides may be green skins or hides, without having been salted for preservation.

Also it is noted that the liquors are recycled and stored for the next treatment operation, thus being more environmentally friendly. Additionally the liquor used for the removal of the fats and proteins can be subject to a further treatment to remove the fats and proteins which themselves are a valuable commodity.

Although the above describes the treatment of the skin or hide with a treatment liquor, it is noted that water maybe used in some instances, such as for rinsing the surface of the skin or hide to remove traces of the previous treating liquor.

Thus in the following claims the term treatment liquid is used, and this is intended to include both treatment liquor and also water.

Thus it will be seen that there is provided according to the invention a process and apparatus for the treatment of hides and skins by which processing the treatment times are greatly reduced.