EP1033412A1 - Method and device for dehairing rodent skins - Google Patents

Abstract

Process for separating the hair from the skins of small rodents involves vigorously beating the rolled-up or open skins in water to detach the hairs, including the bulb portion, and separating the floating hairs from the surface of the water. An Independent claim is also included for an apparatus for separating the hair from the skins of small rodents, comprising means for beating the skins and means for selectively recovering the detached hairs and skins.

Description

The invention relates to a method and a device for separating skin hairs. small animals obtained from the slaughterhouse, for further processing, for example to obtain wool or hair.

PRIOR ART AND PROBLEM POSED

We conventionally know devices in this area, the most often applied to the treatment of sheep skin or ungulates. They include for example passages on tables, or between rollers ( may in particular cite patent documents in this area: FR 2,348,974, for a "skin stripping machine", EP 0 012 089, for a "machine for skinning depilating the skin of abattoir animals ", FR 2 370 096, for a" device for treatment of hides and skins ", US 5,088,999, for a hair removal device, FR 2 518 574, for a "treatment plate for a hair removal device can enchaussenées ", and DE 26 42 500 A1).

With regard to the skins of rabbits, it is notable that the most a large part of the rabbit skins produced by slaughterhouses are unused and destroyed. Techniques exist however to depilate these skins.

They usually use knives that shave the skin, which must be laid flat, and placed on a suitable support (we can cite in this area the patents SU 1 325 077 A1, SU 1 837 074 A1 and RU 2 046 829 C1). This also requires cutting these skins to make a "sheet", so that the skins from slaughterhouses are, as we understand, presented under in the form of an inverted sleeve, the hairs of which are situated inside, and the flesh outside.

It is obvious that the multiplicity of these operations complicates the task separating the hairs from the skin, requires the design of complex machines, and therefore makes the recovery of rabbit hair economically unattractive (or more generally small rodents).

The invention relates to a method and an associated device, to solve the above problems.

STATEMENT OF THE INVENTION

To this end, the invention provides a method for separating the hairs from skins of small rodents, especially rabbits, applied to skins from slaughterhouses in the form of sleeves or open skins, characterized in that it includes a step of detaching the hairs from the skin at the level of the bulb by vigorous mixing in water and a step of separation of the hairs detached and skins in water by density difference, the hairs rising to the surface.

It is understood that the method according to the invention is characterized by the fact that the hairs are detached from the skin at the level of the hair bulb, and not cut flush with the skin, as in previous techniques. This Obviously allows to obtain a hair length greater than what is obtained with traditional techniques, and also simplifies the fitting used, no longer requiring the cutting of the "sleeves" of skin from the slaughterhouse, their drying and putting them substantially flat to pass a blade of cutting hairs. Furthermore, detachment by mixing and separation by difference in hair and skin density allows continuous operation of the process.

Preferably, the step of detaching the hairs from the skin is preceded by fermentation phases of the skins, then wet inflation, and is made by mixing in a humid environment.

This provision corresponds to a favorable implementation of the process, by facilitating the detachment of the hair at the level of the bulb, thanks to a preliminary work of the skin.

• la phase de fermentation est réalisée en étuve dans des caisses aérées ou non, pendant une durée de un à quelques jours, selon une progression inverse de la température ambiante.
• la phase de gonflage humide est réalisée pendant une durée allant de quelques dizaines de minutes à une journée environ, dans un bac rempli d'eau.
• la phase de brassage est réalisée par des groupes de batteurs mus en mouvement oscillant dans une cuve de séparation comportant une alimentation en eau et en peaux préalablement gonflées d'eau. Elle est réalisée à température ambiante, et de l'eau et de l'air sont injectés dans la cuve de séparation.
• le procédé comporte en outre une phase de récupération à la surface de la cuve de séparation des poils détachés de la peau.
• l'alimentation en eau et en peaux de la cuve de séparation est réalisée par pompage par une pompe à piston d'un fluide mêlant de l'eau et des peaux gonflées, stocké dans un réservoir.
• le procédé comporte une phase de récupération et une phase d'essorage des peaux épilées.
• le procédé comporte le recyclage sensiblement en boucle fermée de l'eau de la cuve de séparation.

According to preferential provisions, possibly used in conjunction:

• the fermentation phase is carried out in an oven in ventilated boxes or not, for a period of one to a few days, according to a reverse progression of the ambient temperature.
• the wet inflation phase is carried out for a period ranging from a few tens of minutes to approximately one day, in a tank filled with water.
• the brewing phase is carried out by groups of drummers moving in oscillating motion in a separation tank comprising a supply of water and skins previously swollen with water. It is carried out at room temperature, and water and air are injected into the separation tank.
• the method also includes a recovery phase on the surface of the separation tank for hairs detached from the skin.
• the water and skins are supplied to the separation tank by pumping, by a piston pump, a fluid mixing water and swollen skins, stored in a tank.
• the process includes a recovery phase and a wringing phase for depilated skins.
• the process involves recycling the water in the separation tank substantially in a closed loop.

These different provisions correspond to an implementation simple and efficient process, using known phases as much as possible in the treatment of other skin types, to make it simpler and economical the implementation of the process. Likewise, the devices used are as far as possible compatible with existing installations, in the same concern for simplicity and reuse of existing factories. This then allows a very significant saving of initial investment.

The invention also relates to a device for separating the hairs from skins of small rodents, applied to skins from slaughterhouses in the form of sleeves, characterized in that it comprises a means for mixing the skins and means for selective recovery of hair and skin.

• la figure 1 est un organigramme du procédé d'épilage selon l'invention,
• la figure 2 est un schéma fonctionnel du dispositif d'épilage selon l'invention.
• la figure 3 est une vue d'une variante de moyen de sortie des peaux épilées.

The description and the drawings of a preferred embodiment of the invention, given below, will make it possible to better understand the aims and advantages of the invention. It is clear that this description is given by way of example, and is not limiting. In the drawings:

• FIG. 1 is a flow diagram of the depilation process according to the invention,
• Figure 2 is a block diagram of the epilating device according to the invention.
• Figure 3 is a view of an alternative means of output of depilated skins.

DESCRIPTION OF THE PROCESS

The depilation process according to the invention mainly comprises a step of detaching the hairs from the skin at the level of the bulb by stirring in water, and a step of separating the detached hairs and the skins by density difference.

To reach the stage of detaching the hairs from the skin, work preliminary of said skin is necessary, to facilitate this detachment.

In the method according to the invention, rabbit skins are provided for example by a slaughterhouse, in the form of "sleeves" turned undried, the skin being outside, and the hairs inside the sleeve, due to the mode of operation of slaughterhouses. It is clear that this situation contributes to the complexity of the problem of hair removal.

The only parts that may be cut and removed before treatment are the parts containing hairs of an unacceptable color (for example example black tail when the rest of the hair is substantially white).

When received (at the slaughterhouse outlet), the sleeves are placed in heaps in preferably ventilated boxes, for example of length 140 cm, width 75 cm and height 30 cm, stacked one on top of the other, leaving an air layer of 5 to 6 centimeters between the boxes to ventilate the sleeves. It is clear that these dimensions are given as a preferred example purely indicative, any other dimension being a priori possible.

The first stage of the process is then a stage of fermentation of sleeves, carried out in an oven, according to a technique of a type known to man of art. In such an oven, which is here a room in which are placed a few cases of sleeves, the temperature may be controlled to speed up or slow down the fermentation of the sleeves.

In a practical way, a correct fermentation of the sleeves, resulting in bacterial work, in particular at the level of the hair bulbs, skins whose hairs can be plucked by hand quite easily by handle, is obtained in five to seven days at a temperature of -5 ° C to 10 ° C (winter), or in about two to three days at a temperature of about 20 ° C (in summer).

We see that the fermentation time changes in inverse function the ambient temperature of the oven. It is clear that the temperature of the oven can be increased or cooled as required for skin treatment (acceleration or slowing down of the flow of treated skin).

The fermentation state of the sleeves must be checked in order to achieve a sleeve whose hairs are easily detached, but whose holding of the skins is enough not to tear to shreds (rotting of the skin), which would make it more difficult to separate hairs and skins.

In the second step of the process, once these skin sleeves suitably steamed (and therefore fermented) rabbit, they are transferred to basins (or vats or wagons) with a capacity of a few cubic meters, filled with room temperature water. This step causes swelling of the skins, which soak up water, which further facilitates the detachment of hairs.

The duration of stay of the sleeves in water is of the order of a few tens of minutes (for an ambient temperature of around 18 ° C), but can be extended to approximately one day without significant change in mechanical characteristics of the sleeves.

The third stage of treatment is then a vigorous mixing of sleeves in a separation tank 1 also filled with water. Typically, a few hundred inflated sleeves are vigorously brewed in a water volume of a few cubic meters. Brewing is carried out by groups beaters moving in oscillating motion in the separation tank 1.

This mixing has the effect of rubbing the inflated sleeves against others. Brewing provides hair and skin with energy mechanical enough to cause their detachment from the skin at the level of the bulb. It should be noted that this mixing allows the detachment of the hairs, even when the sleeves are turned over, with the hairs located inside the muff. Naturally, the process also works on skins open.

A flow of air (a few tens of m3 per hour) and water (20 m3 per hour, variable from 10 to 50 m3), injected substantially at the bottom of the tank separation 1, then causes the detached hairs (of density less than that of skins, and tending to float anyway) towards the surface of the tank separation 1.

Permanent injection of water and air at the bottom of the separation tank 1 causes a permanent overflow of the separation tank 1, on one side chosen lower height, causing a surface movement resulting loose hairs, and where the loose hairs are collected, for example on a narrow grid allowing water to pass through.

The feed water is recycled substantially in a closed loop, from so that only about a few cubic meters of water are used per hour by the separation tank, which increases the "load" of water (mainly in fat) before its treatment in a unit adapted and conventional treatment near the epilation units.

The brewing time of each sleeve is of the order of approximately twenty to thirty minutes, after which a very large proportion of the hairs are found detached from the skin.

In a later step which goes beyond the scope of the present invention, the loose hairs are optionally washed and dried in a conventional manner, before spinning or other processing.

The skins are collected at the end of a separation tank 1. They are almost completely free of hair, and can therefore be used for glue or collagen, fertilizer, etc. manufacturing applications according to techniques also known per se, and outside the scope of the present invention.

DESCRIPTION OF THE DEVICE

The device used for this mixing will now be described, by way of non-limiting example, with regard to FIG. 2. It consists of a partition 1, of substantially parallelepiped shape, or slightly flared as seen in Figure 2, with a capacity for example of a few cubic meters (depending on the desired yield), and conventionally made of metal. The dimensions of the separation tank 1 are here 2 meters in length, 80 centimeters in width, and 1 meter in height.

This separation tank 1 has a water supply pipe 3 and in skins previously swollen with water, which is a metallic tube of diameter approximately 15 cm.

The supply consists in the present nonlimiting example of a tank 4 with a volume of approximately 1 m3, permanently supplied with water.

In the lower part of this tank, a 15 cm metal pipe 5 diameter approximately is connected to a piston pump 6 of conventional type, of power 3 to 10 kW approximately, which injects the "mixture" of water and inflated sleeves of water in the separation tank 1 via the pipe 3, which ends in the lower part of said separation tank 1. It is clear that the speed of operation of the piston pump 6 is adjusted according to the volume of sleeves that you want to inject into the separation tank at any time.

At the lower part of the separation tank 1 (below the inlet of the supply pipe 3) is arranged a low grid 7, intended to constitute a limit for movements of the sleeves. This low grid 7, placed at about 10 cm from the bottom of the separation tank 1, determines a lower part 8 of tank comprising air and water inlets 9 to be injected, and a part upper 10 of tank, intended to accommodate the sleeves to be brewed. Grid low 7 allows good diffusion of the air and water injected into the separation 1.

Upstream of the air and water inlets 9 to be injected, produced in the form of pierced pipe extending over the entire bottom length of the separation tank 1, a conventional device for injecting water and air into the separation tank allows continuous or pulsed injection, as required.

The stirring device also includes a stirring means, which includes several groups of drummers 11 (also called ramps brewing) inserted, immersed in the upper part 10 of the tank (represented in symbolic form by slashes interspersed on the figure 2). Each mixer 11 has a length of 80 cm, and is made, in the this example, in the form of a steel tube with a square section of 5 x 5 cm.

For each group of beaters 11, the beaters 11 are joined by their upper part to an upper bar 14, which allows their training simultaneous in movement in the separation tank 1.

These groups of drummers 11 are moved in lateral oscillating movement. by a gear motor 12 (or by a jack) and a mechanical mounting 13 of the type classic that causes the beater groups 11 to oscillate to a adjustable frequency and around 60 to 140 movements per minute.

In the example described without limitation and adapted to the treatment of around 1000 skins per hour, four groups of drummers are trained in a sense and four group of beaters 11 in the opposite direction through the gear motor 12 with four cylinders and four connecting rods. The amplitude of movement of beaters 11 in the separation tank 1 is a few tens of centimeters (typically 20 to 40 cm).

The spacing between the drummers 11 of the different groups is a few millimeters (4 to 7 mm typically), which prevents the pieces from skins to rise to the surface with loose hairs.

A horizontal water injection (not shown in Figure 2) is placed under the surface of the separation tank 1 along one of its sides, to create a surface movement of the water, and thus cause the hairs detached supernatant.

The separation tank 1 also includes a zone of overflow 15 located opposite this side, and a narrow grid (not shown) which retains loose hairs but lets water overflowing from the separation tank 1.

Below the level of the surface of the separation tank 1, a outlet 16 for shaved skin is planned, with a diameter of approximately 15 cm. It is connected to a piston pump 17, of conventional type, which injects the skins into a wringing device 18, making it possible to recover a large volume of water, then reinjected into the separation tank 1 or into the tank 4. This device for example consists of a vertical perforated cylinder 19 integrated in a second sealed external cylinder 20. In the lower part of this cylinder watertight exterior 20, a hose 21 brings the spin water back to the separation 1.

The wrung skins are transferred by a pipe 22 secured to the upper part of the perforated cylinder 19 in a storage tank 2 for treatment subsequent classic type.

The same wringing system can be used to wring out the hairs detached after their recovery.

The invention applies in particular to the skins of rabbits, which are produced regularly by rabbit slaughterhouses, which are very often destroyed for lack of being able to be correctly treated. But the present invention also applies to the treatment of the skins of other animals such as rodents.

VARIANTS

Many variations can be considered depending on the Terms of use.

In a variant implementation of the method, the recovery of loose hairs on the surface of the separation tank 1 can be facilitated by the creating a movement on the surface of the separation tank is achieved by injection of a horizontal water flow just below the surface of the separation tank 1 along one of its sides.

In another variant, this recovery of loose hairs is performed by a regular scraping device from the surface of the separation 1. In yet another variant, a treadmill placed flush with the surface permanently pulls loose hairs out of the separation tank 1.

The process can naturally be carried out either continuously, with a permanent water supply and inflated sleeves, and continuous recovery separate hairs and skins. In this case, the supply of water and skins of the separation tank is produced by pumping by a piston pump of a fluid mixing water and swollen skins, stored in a tank 4.

On the contrary, it can be carried out in batches of a few cubic meters (a few hundred skins), the separation tank 1 being emptied of the skins shaved inside, after each batch has been brewed for a period of a few tens of minutes.

In an alternative method of inflating the skins, a air supply is also provided at the bottom of the inflation tank, to speed up the process.

It is clear that, as a variant, many brewing devices can be considered, for example: hydraulic cylinders connected to arms or sheets articulated in the tank, means for tilting the tank itself, a rotation device inside the tank.

In an alternative embodiment of the stirring device, this mixing is carried out by oscillating movements in a direction substantially vertical, for example of a group of bars arranged in comb, moved by a hydraulic cylinder

In another variant of the stirring device, the detachment of the hair is obtained by an ultrasonic process. In this case, one or more ultrasonic devices are attached to the walls of the tank and facilitate by vibrations induced detachment of the hairs.

In yet another variant, several pulsed air jets created in the separation tank 1 in different directions create by themselves a brewing movement.

These different variants can optionally be combined.

In a variant of the stirring device, the volume of the separation 1 is increased (with dimensions for example of 6 meters length, 1.5 meters in width and 1 meter in height), so as to allow simultaneous treatment of approximately 2000 skins, and therefore reach a flow of 5000 to 6000 skins per hour. The sleeves are then injected at one end of the tank. separation 1, and the shaved hairs and skins are continuously recovered to each other end of the separation tank 1.

In yet another variant implementation of the method, the same pumping device by piston pump and 15 cm diameter hose approximately is used for the transfer of the sleeves from the ovens to several inflation tanks 4 (similar to a large tank), this which further reduces the handling to be performed, and allows better process automation.

In this variant, each inflation basin 4 can be sized to accommodate 40,000 skins during inflation, each pool having a valve, and a mobile pump 6 secured to flexible hoses 3, 5 allowing to choose among the basins 4 the source of supply of the tank of separation 1 at a given time. Such an arrangement makes it possible to envisage a continuous treatment up to more than 100,000 skins per day.

In a variant of the process not using stirring in the medium wet, the sleeves, once steamed and inflated, are hung in a chain, and passed between cylinders with rubber blades for example, which carry out the work of detaching the hair at the level of the bulb, in a similar manner to a manual removal.

In yet another variant (FIG. 3), the skins are removed on the entire width of the tank, and this tank fills up suddenly, allowing improved skin advancement. In this case, the outlet pump is in permanently in operation. A sliding door 23 (or door fixed by suction cup or other conventional means) is secured to an opening means 24 and chain, sprocket, gearmotor closure. It is opened very quickly on along slides 25, and stays open for about 20 seconds. A counter blade 26 is arranged opposite the sliding door 23, to improve the functioning of the whole.

The tank then fills very quickly. The door is then closed, also quickly, and remains closed for a period of, for example, two minutes twenty seconds (tank emptying time). Then the cycle resumes with a new opening of the door etc.

The scope of the present invention is not limited to the details of the embodiments above considered by way of example, but extends to contrary to modifications within the reach of ordinary skill in the art.

Claims (21)

Process for separating the hairs from the skins of small rodents, especially rabbits, applied to skins from slaughterhouses in the form of sleeves or open skins, characterized in that it includes a step of detachment of the hairs from the skin at the level of the bulb by vigorous mixing of the sleeves or open skins in water and a hair separation step detached and skins in water by density difference, the hairs rising to the surface. Method according to claim 1, characterized in that the step of detachment of hair from the skin is preceded by fermentation phases of skins, then wet swelling. Method according to claim 2, characterized in that the phase of fermentation is carried out in an oven, for a period of one to a few days, according to a reverse progression of the ambient temperature. Process according to any one of Claims 2 to 3, characterized in that the wet inflation phase is carried out during a duration ranging from a few tens of minutes to about a day, in a bin filled with water. Process according to any one of Claims 1 to 4, characterized in that the vigorous mixing is carried out by groups of beaters moving in oscillating motion in a separation tank (1) comprising a water supply (3) and skins previously swollen with water. Method according to claim 5, characterized in that the mixing vigorous is carried out at room temperature, and in that water and air are injected into the separation tank (1). Process according to any one of Claims 5 to 6, characterized in that the mixing of the skins lasts a few tens of minutes for a frequency of movement of groups of drummers of the order about 60 to 140 movements per minute. Process according to any one of Claims 1 to 7, characterized in that it also includes a recovery phase on the surface of the separation tank (1) of the detached hairs raised to the surface. Method according to claim 8, characterized in that the recovery is achieved by creating a movement on the surface of the tank separation (1) causing the loose hairs to a recovery means. Method according to claim 9, characterized in that the creation movement on the surface of the separation tank (1) is achieved by injection of a horizontal water flow just below the surface of the separation tank (1) along one of its sides. Process according to any one of Claims 5 to 10, characterized in that the supply of water and skins to the separation tank (1) is produced by pumping by a piston pump (6) a fluid mixing water and swollen skins, stored in a tank (4). Process according to any one of Claims 1 to 11, characterized in that it includes a recovery phase and a phase wringing of depilated skins. Method according to claim 12, characterized in that the phase wringing of the depilated skins is carried out by pumping the skins in a perforated cylinder (19) with water. Method according to any one of claims 7 or 13, characterized in that it involves substantially closed-loop recycling of water from the separation tank. Device for separating the hairs from the skins of small rodents, applied to skins from slaughterhouses in the form of sleeves or skins open, characterized in that it comprises a means of mixing (11 to 15) of the skins and means for the selective recovery of loose hairs and skins shaved. Device according to claim 15, characterized in that it is consisting of a separation tank (1) comprising a supply means (3 to 6) in water and in skins previously swollen with water, and in that the means of brewing comprises groups of beaters (11) moved in oscillating motion. Device according to any one of Claims 15 to 16, characterized in that it comprises continuous or pulsed injection means (9) water and air in the separation tank (1). Device according to claim 17, characterized in that it comprises a low grid (7) in the separation tank (1), disposed between a lower part (8) of the tank comprising air and water inlets (9) to be injected, and an upper part (10) of the tank, intended to receive water containing skins. Device according to any one of Claims 16 to 18, characterized in that it includes a means for driving (12, 13) groups beaters (11) at a frequency of the order of about 60 to 140 movements per minute. Device according to any one of Claims 16 to 19, characterized in that the means for supplying water and skins to the tank separation (1) comprises a tank (4) filled with water and skins, and a pump piston (6) connected to the tank (4) and to the separation tank (1) by pipes (3, 5) about 15 cm in diameter. Device according to any one of claims 15 to 20, characterized in that the means for selective recovery of the hairs comprises a means for injecting a horizontal flow of water just below the surface of the separation (1) along one of its sides, a continuous overflow zone (15) located opposite this side.

Images