Plant for drying pretreated flexible sheet products

Abstract

A drying plant (1) for drying pretreated flexible sheet products, having at least one side on which a layer of a chemical compound has previously been deposited, said system (1) comprising feeding means (2) for feeding the sheet products in a direction (L), drying means (3) for drying the products as they are being fed, which have at least open operating unit (5) with a chamber (6) through which the feeding means (2) are designed to pass, and with at least one applicator (10) connected to a respective generator (11) for application of an alternating electromagnetic field in the RF range and acontrol unit (1 6), for controlling the generator (11) and / or the applicator (10). The field has an oscillation frequency that ranges from 300 kHz to 300MHz and is preferably 27.12 MHz at least one air blowing means (18) (18) for delivering hot air and / or at least one suction means (19) are provided. The control unit (16) is configured to change the speed of the feeding means (2) or to change theelectromagnetic field application time. Sensor means are further provided, for detecting one or more physical and / or thermodynamic parameters of the operating unit (5) and the temperature of the sheetand for controlling the means (2, 18, 19) separately from or in combination with each other and carry out complete drying of the chemical compound layer.

Description

technical field [0001] The present invention generally finds application in the field of tanning and relates in particular to an apparatus for drying pretreated flexible sheet products such as industrial hides, skins, artificial leather or leather derivatives. Background technique [0002] After various tanning, retanning and dyeing treatments, hides and skins are known to often exhibit surface defects that develop naturally during the life of the animal (scratches due to puncture wounds, contact with barbed wire or thorns) marks), or from poor preservation of the leather after peeling. [0003] In these cases, once the hides have been dried, they undergo a surface treatment commonly referred to as finishing, whereby the imperfections are removed or made less visible for better use of the hide. [0004] During chemical finishing, compounds, usually in liquid form, are deposited on the hide to form a grain layer that can be of varying thickness or have elasticity or toughnes...

AI Technical Summary

Problems solved by technology

[0017] The first disadvantage of this setup is that the device does not allow for feedback-responsive adjustment of the operation of the generator and applicator according to the operating conditions of the drying unit

[0018] An added downside is that the hides have to go through two drying processes to achieve the best results

This disadvantage involves an increase in overall tooling costs

[0019] Another disadvantage is that the electrodes are arranged in the drying unit in a conventional geometry, which cannot be changed to optimize the application of the electromagnetic field on the hides as they are fed

[0020] Another disadvantage is that using a single radio frequency limits the drying efficiency of the compound and hides and leads to a build-up of residual moisture in the drying unit

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