CH616056A5 - Method for calibrating a continuous envelope (casing) stuffed with a food product - Google Patents

Abstract

It is aimed to obtain satisfactory regulating of the stuffing of a continuous and pleated envelope (casing) with a food product. The envelope (casing) (11) is unpleated by drawing over a calibrating disk (15). This envelope (casing) is then contracted by passing into the opening (21) of a retention ring (19) as it is stuffed with a food product (23) introduced by a mandrel (13) mounted centrally in the disk (15) and the ring (19). The width of the edge (17) of the disk is determined relative to the diameter of the latter, so as to permit prior adjustment of the diameter to which the envelope (casing) (11) is stuffed. The use relates to the production of sausages. <IMAGE>

Description

The invention relates to a method for calibrating the size of an envelope during stuffing with a food product and a calibration disk for implementing the method.

In the meat packaging industry, there are processes for automatic and semi-automatic filling of various types of envelopes with a viscous meat emulsion. In general, these methods consist in positioning a section of pleated envelope, consisting of a continuous film, on a tamping mandrel, then in continuously unfolding the envelope and filling it with a viscous emulsion of meat introduced under pressure. in the tamping mandrel and in the envelope. The expression envelope or tubular envelope designates an envelope or a hose made of natural or synthetic material, and the expression section of envelope designates a continuous length of tubular envelope. Pleated tubular casings are sometimes called sticks, the latter being made up of long lengths of casing of relatively large diameter, pleated and compressed into short and rigid sections. As a variant, the sticks may consist of a cartridge comprising a pleated and compressed envelope, surrounded by a retaining sleeve. There are known apparatus and methods for producing pleated tubular cellulosic envelopes for food products, as described, for example, in United States Patent Nos. 2983949 and 2984574. These apparatuses can be used for the preparation of pleated and compressed tubular envelopes, for which the compression ratios (ratio between the non-pleated length and the pleated length) are of the order of at least 40 and can reach approximately 100 or more. Suitable machines for stuffing foodstuffs can be used to fill lengths of envelopes and form chains or strings of sausages or other products of unit dimensions, consisting of viscous particulate or minced materials, for example meat emulsions or others.

For the production of sausages and other food products, the finely divided meat compositions, generally called emulsions, are conventionally introduced into long tubular casings which, as mentioned previously, can be made of natural or synthetic materials. Large diameter sausages, marketed in the form of packaged multiple slices, are generally produced in envelopes ranging in diameter from around 75 to 130 mm. For the production of these sausages, an envelope of predetermined length, closed at one end by a staple or a clamp is first threaded manually on the end of a tamping mandrel, then filled with a food emulsion. When the tamping operation progresses, the closed end of the envelope moves towards the outside of the mandrel and the envelope unfolds and resumes its initial length or a very similar length. The envelope thus filled is thus ligated, twisted or stapled into cylindrical sections of predetermined unit length.

The food emulsion thus wrapped and packed is then cooked and smoked by the implementation of one of several conventional processes, chosen according to the product to be produced, then it is then generally cut into slices and packaged to form articles of a predetermined weight and containing a given number of slices for retail sale. The high speed cutting devices used for these packaging operations are preset to cut a number of slices of predetermined weight, in order to produce packages of the same weight. Consequently, it is important from a commercial point of view that large diameter sausages have, in the final state, an approximately uniform diameter from one end to the other and from one piece to another. , with the same nominal dimensions. In addition, the diameter of the slices must be uniform and precise, so that these slices can be placed in rigid prefabricated and frequently used packaging.

The two rounded, roughly hemispherical ends of a large-diameter sausage casing filled with a food emulsion are generally not used for the production of packages of uniform weight and are discarded or reused. It is therefore also important to produce sausages of large diameter with straight and uniform ends, so as to reduce the quantity of food product cut and rejected from the uniform cylindrical section.

The use, for many years, of envelopes of manufactured sausages, for example made of loose cellulose or reinforced with fibers, has made it possible to determine optimal conditions of stuffing and processing for various types of sausages. These usually need to be wrapped or filled to initial diameters or untreated, chosen and recommended for optimal results. In commercial practice, a recommended packing diameter for each size and type of envelope has been established and calculated in recommended working procedures, determined by the envelope manufacturer for the guidance of the sausage manufacturer.

When an envelope is insufficiently filled and its diameter is less than the recommended initial diameter, the result is a product whose diameter is not uniform from one end to the other and from one part to another. In addition, this product has an undesirable wrinkled appearance and the treated sausage may have an emulsion rupture, causing undesirable pockets of fat or liquid to appear.

When an envelope is filled in excess, beyond the recommended initial diameter, it may split or cut in the tamping station or thereafter, during its transport or during the cooking and / or smoking operations. The result

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costly loss of emulsion and labor costs for cleaning.

The apparatuses and processes implemented for many years for the preparation of wrapped food products and, in particular, food products surrounded by large diameter envelopes, rely largely, but not exclusively, on manual intervention for the control of stuffing. food emulsion to form chains or strings of sausage each having a predetermined length. Progress has recently been made on the introduction of the automatic control of the tamping operation for the preparation of wrapped products of uniform dimensions, as described, for example, in United States Patent Nos. 2871508, N ° 2999270, N ° 3264679, N ° 3317950, N ° 3454980, N ° 3547588, N ° 3553769, N ° 3621513 and N ° 3751764. French patent application N ° 76.32925, filed on October 29, 1976 by Vytautas Kupcikevicius and Anton Leroy Mika describes an interesting embodiment in this area.

The automatic sausage stuffing process, summarized in the aforementioned French patent application No. 76.32925, involves the use of a ring or a calibration disc placed inside the envelope during stuffing and cooperating with an annular retaining ring disposed outside the envelope, at an adjustable distance from the calibration disc along the envelope. The diameter of the outside edge of the calibration disc is greater than the inside diameter of the envelope and the inside diameter of the retaining ring is less than the outside diameter of the finished sausage. The calibration disc and the retaining ring are aligned coaxially with the stuffing mandrel of the sausage production apparatus and a device adjusts the linear spacing between this disc and this ring.

By reducing this linear spacing, the envelope, passing from its stretching diameter which it presents when it is unfolded on the calibration disc to its prescribed diameter, which it presents when passing between the external surface of the mandrel jamming and the inner edge of the retaining ring, undergoes an abrupt change in direction and this results in an increase in the friction forces in the areas where this envelope comes into contact with these control elements. The resistance to advancement of the envelope or the retaining force exerted on the latter therefore increases. Conversely, by increasing the linear spacing between the calibration disc and the retaining ring, the casing, passing between these two elements with which it comes into contact, undergoes a less abrupt change in direction than previously and results in a reduction of the friction forces in the contact zones and, consequently, a reduction in the resistance opposed to the advancement of the envelope or in the retaining force exerted on the latter. It therefore appears that, for a given and coherent group of operating parameters, including the type and state of the envelope, the consistency of the emulsion, the speed and the pressure under which the emulsion is discharged from the pump. and, for example, the state of wear of the parts of the tamping device, the increase in the retaining force exerted on the envelope tends to raise the tamping pressure of this envelope and to increase the diameter of this last, while a decrease in the retaining force tends to lower the packing pressure and reduce the diameter of the product.

Since it is desired to keep the product at a constant diameter for the reasons indicated above, the linear spacing between the calibration disc and the retaining ring is modified in a controlled manner, in order to compensate for the variations and fluctuations of the other parameters indicated above and whose control is not as easy as that of the disc and the ring.

Thus, in the prior art and as described in the aforementioned French patent application No. 76.32925, the adjustment of the retaining force exerted on the envelope is carried out by controlling the spacing between the calibration disc and the retaining ring.

Improvements made to the apparatus and to the process described in the aforementioned application have shown that it was necessary to increase the degree of control and the range of variation of the diameter of the products, not to obtain products of more varying diameter, but to increase the possibilities of compensation presented by the stuffing apparatus as a function of uncertain variations in the compositions and materials constituting the envelope, variations in meat emulsions and other operating parameters. From the point of view of technical development, this constituted an objective to be achieved in order to allow the envelope to be stuffed insufficiently and / or in excess during any filling operation, to a degree greater than that which can be obtained previously and with an adjustment and improved accuracy. It has also appeared and it has been justified that, while an increase in the diameter of the calibration disc results in an increase in the retaining force exerted on the casing and can raise, to a certain extent, the excess stuffing limit of the controlled range, such a measure has no effect on the insufficient stuffing limit and, if it is too accentuated, it can cause the envelope to be stretched to a diameter sufficiently greater than that of the finished sausage, to that the elastic limit of the envelope is exceeded or that the envelope is otherwise affected. In the case where an undersized calibration disc is used to push the limit of insufficient padding of the controlled range, the results obtained are different from the previous ones, but also undesirable, because the envelope is not stretched enough to present a uniform size, in the stretched state, and to obtain a stuffed product having a uniform and precise diameter.

The invention is designed and developed to increase the degree of control and the controlled range between the diameters resulting from excess stuffing and those resulting from insufficient stuffing of a food product envelope.

The invention makes it possible to significantly increase the adjustment capacity to compensate for and correct a greater number and a greater variety of variable operating parameters, adjustment faults and faults resulting from the wear of the parts used for the stuffing of an envelope with a food product.

The invention relates to the calibration method defined in claim 1, as well as to the calibration disc defined in claim 3.

The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting examples and in which:

fig. 1 is a schematic elevation, with partial section, of the disc according to the invention mounted on a tamping device, and FIGS. 2 to 5 are partial and schematic cross sections showing various embodiments of calibration discs according to the invention.

Fig. 1 shows in section a section of casing 11 for food products, placed on the mandrel 13 for stuffing a filling machine. Only the parts of this machine necessary for understanding the operation of the invention are shown in this figure. The envelope 11 is shown in the pleated state to the right of the figure. It is unfolded and filled by moving from right to left. The left side of fig. 1 shows this stuffed envelope.

A calibration disc 15 is mounted concentrically on the tamping mandrel 13, inside the envelope 11, so that its outer circumferential edge 17 slides against the inner circumferential surface of the envelope 11, near the pleated section. of the latter.

A retaining ring 19, which has an opening 21, the diameter of which is less than the outside diameter of the finished sausage, is arranged concentrically on the tamping mandrel 13, near the end of the latter, as shown in

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fig. 1. In the embodiment shown, the retaining ring 19 assumes a second function which consists in keeping the envelope applied tightly and hermetically against the external surface of the mandrel, in order to prevent any backflow of the emulsion into the non-stretched section. filled, but unfolded, with the envelope. It should be noted that the calibration disc described can be used advantageously with other embodiments of retaining rings. It is not essential, for example, that the opening 21 of the retaining ring is small enough to carry the envelope hermetically on the tamping mandrel. It is sufficient that the opening 21 of the retaining ring is small enough to contract the envelope to the desired degree and necessary for obtaining dimension control in the desired range.

When an emulsion 23 of food product, discharged under pressure by a pump (not shown), is introduced into the casing 11 by the stuffing mandrel 13, this casing 11 is filled as shown on the left in FIG. 1. The envelope 11, pleated, is stretched and expanded continuously passing over the edge 17 of the calibration disc 15, then it is contracted circumferentially and folded back to pass into the opening 21 of the retaining ring 19. By combining the adjustment of the distance X indicated in fig. 1, the diameter D of the calibration disc and the relationship between the width W of the edge of this disc and its diameter D, according to the W / D ratio, it is possible to determine the amplitude of the retaining force or of the resistance exerted on the envelope when it is stretched passing over the edge 17 of the calibration disc 15, then tightened in the opening 21 of the retaining ring 19 and finally advanced until it is completely packed. When the distance X is increased, as described above, the resistant or retaining force exerted on the envelope decreases and the stuffing of the latter tends to decrease, while a decrease in the distance X tends to increase this stuffing.

Experience has shown, during the period of development of the disc described, that it was desirable to be able to stuff in excess the product in order to increase the diameter by 0.25 mm, and also to be able to carry out an insufficient stuffing. causing a reduction in diameter of 1.5 mm compared to the tamping diameter recommended in the industry. As described above, it appeared that an increase or a decrease in the diameter D of the calibration disc does not make it possible to obtain this result. It also appeared that the maximum variation of the distance X which can be obtained practically between the calibration disc 15 and the retaining ring 19 also does not allow the desired objective to be achieved, any more than the combination of these variable parameters. It was therefore thought that an increase in the width of the surface of the edge of the calibration disc could produce the desired result.

Work has focused on the testing of calibration discs with a diameter varying between 3.8 and 12.5 cm. For each diameter tested, discs with edges of a width equal to 0.32, 0.64, 1.27, 1.91, 2.54, 3.81 and 7.62 cm were used.

These tests have led to the conclusion that calibration discs having an edge with a width of less than 0.64 cm and greater than 3.81 cm do not allow the desired result to be obtained, but that substantially different jams are obtained. with calibration discs which, at all the diameters tested, have an edge width of between 0.64 and 2.54 cm. These tests also showed that, for the diameters of the discs used, the width of the edge allowing the most efficient results to be obtained is equal to 1.91 cm.

From the data thus obtained, the range of ratios between the width W of the edge of the calibration disc and the diameter D of the latter, that is to say the W / D ratio, is calculated. The lower limit of this range, corresponding to the value W / D = 0.05, is calculated by dividing the smallest width of the edge, namely 0.64 cm, by the maximum diameter of the calibration disc, c ' i.e. 12.7 cm, and the upper limit of the range, corresponding to the value W / D = 1, is calculated by dividing the largest edge width equal to 3.81 cm, by the smallest diameter of the disc in question, namely 3.81 cm also.

Likewise, the narrowest and preferred range for these ratios is calculated by dividing the largest width of the edge of the calibration disc, i.e. W = 1.91 cm, by the largest diameter of the disc, at know D = 12.7 cm, so that. get the value 0.15 for the lower limit of this range. The width W = 1.91 cm is then divided by the smallest diameter of the disc considered, namely D = 3.81 cm, so as to obtain 0.5, this value constituting the upper limit of the preferred range.

The calibration disc 15 shown in FIG. 1 appears in the form of a cup. Figs. 2 to 5 show other embodiments of the calibration disc according to the invention. Fig. 2 represents this disk in the form of a solid ring,

while fig. 3 shows it in a form opposite to that of the disc 15 of FIG. 1. Fig. 4 shows a calibration disc having a cross section in T, and FIG. 5 shows a variant of the calibration disc with a T-shaped cross section. All these embodiments, as well as others not shown, fall within the scope of the invention, provided that the criteria establishing the relationships between the width of the edge of the disc and the diameter of the latter are respected.

The calibration disc described above can advantageously be made of polyethylene, styrene and stainless steel. It can however be made of other materials, although those mentioned have given satisfaction during the tests.

The calibration disc according to the invention can be used satisfactorily with certain variants of tamping devices, including devices in which retaining rings have a relatively large opening 21 through which the tamping mandrel passes. The calibration disc according to the invention, in particular in these embodiments comprising an edge projecting in the direction of advance of the envelope during filling, is particularly advantageous to be implemented in the apparatus and the method of control of the dimensions to which an envelope is stuffed with a food product, described in the patent application of the United States of America No. 686425, filed on May 14, 1976 by Paul Howard Frey and Vytautas Kupcikevicius.

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1 sheet of drawings

Claims (6)

616,056 1. Method for calibrating an envelope during stuffing with a food product, the envelope having in the unstretched state a given internal diameter, and being first expanded by internal circumferential contact, then contracted by external circumferential contact , the method being characterized in that it consists in continuously maintaining the circumferential contact and in maintaining the width over which this contact is made at a value of between 0.05 and 1 times the internal diameter presented by the envelope to the location of said inner circumferential contact, and to maintain the latter on a diameter (D) greater than the given internal diameter. 2. Method according to claim 1, characterized in that it consists in maintaining the width of the circumferential contact at a value between 0.15 and 0.5 times the diameter presented by the envelope at the location of this circumferential contact interior. 2 3. Calibration disc for implementing the method according to claim 1, the envelope having in the unstretched state a given internal diameter, characterized in that it has a diameter (D) greater than the given internal diameter of the envelope in which it is placed, the width of the circumferential edge of this disc being between 0.05 and 1 times the overall diameter of the disc. 4. Disc according to claim 3, characterized in that the width of its edge is between 0.15 and 0.5 times its overall diameter. 5. Disc according to claim 3 or 4, characterized in that it is made of stainless steel. 6. Disc according to claim 4 or 5, characterized in that it is made of polyethylene or styrene.