Abstract: A vacuum apparatus for industrial hide driers with multiple beds (2) includes a circuit with an open end (17) having arranged in a series: a vapor manifold (7) for each bed; a first condenser (8) inserted in each manifold; a first condensate separator (10) at the output of the various condensers (8); a main vacuum pump (16) to gradually reduce the absolute pressure in the circuit to a first upper value (Ps). A particular feature of the system consists of the fact that it has a secondary aspiration device (19) which is arranged upstream of the main vacuum pump (16) to operate in series to this pump when the first value of the absolute pressure (Ps) is reached, so as to further reduce the pressure of the circuit to a second lower value (Pi). The upper value (Ps) of the absolute pressure is 40 to 100 mbar; the second lower value (P1) of the absolute pressure is 15 to 1 mbar. The device (19) is a high-capacity, low-head blower.

Abstract: The method includes the steps of: preheating a selected volume of product to a temperature proximate to the maximum temperature of the treatment; irradiating the product with an alternating electromagnetic field in order to heat the product to approximately 50.degree. C.; maintaining the product at a substantially constant temperature for a set time; cooling the product to a temperature close to the packaging temperature. An apparatus for performing the above method includes a pair of facing emitting surfaces connected to the terminals of an oscillator operating below 1 GHz and set to heat the product to a maximum temperature of approximately 50.degree. C. The apparatus also includes a thermally insulated region to maintain the product at the maximum temperature of the treatment for a selected time adapted to ensure the complete destruction of the bacterial and sporal loads.

Abstract: A method for softening and stretching tanned hides, in a substantially manner, by applying on both sides of the hides opposite and reciprocating forces with a predetermined stroke which are substantially perpendicular to the surfaces of the hides, such forces being applied, on one side of the hides, by means of rigid elements acting on mutually spaced portions of the work area and, on the other side, by means of an elastically yielding planar uniform support acting on the entire work area. The rigid elements have active dome shaped portions with a radius of curvature which is greater than the stroke of application of the opposite forces.

Abstract: The present invention relates to a vacuum drying machine for tanned skins, with multiple work surfaces, which comprises a fixed framework with at least two substantially vertical uprights which extend to the side of a plurality of vertically movable stacked platforms, each of which upwardly defines a work surface, and is provided below with a cover for the underlying platform. The vacuum drying machine is characterized in that at least one of the platforms is characterized in that at least one of the platforms is coupled to the movable liners of at least two linear double-action cylinders, each one being located at one of the uprights, the upper ends of the stems thereof being connected to the top of the matching upright.

Abstract: The present invention relates to a vacuum drying machine with multiple tables for drying industrial hides and similar products, including a fixed supporting frame which supports a plurality of controllably vertically movable horizontal work tables. Each of the tables has, on its upper face, a supporting and heating plate for supporting and heating the hides and, on its lower face, a closing cover which can sealingly engage the upper face of the underlying table so as to define a vacuum drying chamber. An intermediate supporting structure is provided so as to be vertically movable inside the fixed supporting frame. The tables are vertically movable in the intermediate supporting structure so as to move telescopingly with respect to the fixed supporting frame.