SU687124A1 - Method of stretching and softening of leathers - Google Patents

Description

(54) METHOD OF TRIQUE AND MAGNIFICATION OF THE SKIN

one

The invention relates to light industry, in particular to the leather industry, and is intended for use in the operation of tightening and softening leather.

There is a known method of pulling and softening leathers, in which the skin is subjected to repeated stretching and bending with the help of mechanical vibrating softening tools equipped with 1.

However, in this way, the skin is subjected to an uneven contact impact of spikes across the entire area, leading to local compaction of its surface layer. The deformation of the skin occurs instantly with greater acceleration, which leads to a partial disruption of the structure and causes a decrease in its strength.

There is also known a method of pulling and softening the skin, which involves pressing the skin against the base with holes and deforming the skin by acting on it with a gaseous medium during the relative movement of the skin along the base 2.

The disadvantage of this method is the inability to perform multiple deformations of the treated skin by alternating pressure and discharging the gaseous medium acting on the skin, which does not allow to intensify the treatment process.

The purpose of the invention is to intensify the process of tightening and softening. This is achieved due to the fact that exposure of the skin to the gaseous medium is carried out on both sides of the skin with alternating pressure and discharge of the gaseous medium.

FIG. Figures 1 and 2 show variants of the technical implementation of the method of tightening and softening the skin.

Claims (2)

In the first embodiment (see Fig. 1), the skin 1 is moved in the working area in which the cylinders 2 are arranged in two rows, for example in a slanting order so that the outlets of the upper and lower cylinders coincide. Mentioned lower tier cylinders form the base. After pressing the skin with the cylinders of the upper rus to the cylinder of the lower rus, the skin areas bounded around the perimeter of the upper and lower pairs of cylinders are exposed to gaseous medium, such as air, alternately on both sides of the skin with alternating pressure and discharge of the gaseous medium. The gaseous medium is compressed due to the movement of the pistons 3 in one cylinder in one direction, and the discharge due to their movement in the other cylinders in the other, opposite direction. At the same time, skin areas, like a membrane, experience tensile and bending forces. As the skin progresses and with repeated alternation of pressure and discharge in the cylinders, the entire skin intensively softens and stretches. Since the pressure and discharge of the gaseous medium is accompanied by a smooth transition from one state to another, the load on the skin areas also smoothly changes from zero to maximum. At the same time there is no local contact sealing of the superficial layers of the skin. The degree of compression and discharge is regulated, for example, by decreasing or increasing the stroke of the piston in the cylinders. In the second embodiment (see Fig. 2), the cylinders can be located in one Rus. At the same time, the skin areas moving over the cylinder openings also experience tensile and bending forces. The skin I, transported by the rollers 4, is simultaneously held by them over the openings of the cylinders 2 during processing. At the experimental facility, made in VNIILtekmash, samples of various types of chrome leather were processed. The optimal treatment effect is achieved when pressure is alternated and discharged in cylinders with a frequency of 3-5 Hz at a pressure (19.62-49.05). 10 Pa. The larger of the indicated values of frequency and pressure corresponded to the skin treatment regimes developed from the skins of heavy weights (bychins, adroit). The proposed method of pulling and softening the leathers by affecting the material being processed with a smoothly growing contactless load, provides, along with the intensification of the process, an improvement in the quality and marketable properties of the finished leather, as well as an increase in their yield. Claims method of tightening and softening the skin, including pressing the skin against the base with holes and deforming the skin by acting on it with gaseous medium during relative movement of the skin along the base, characterized in that, in order to intensify the process of tightening and softening, the effect gaseous medium is applied to the skin on two sides of the skin with alternating pressure and discharge of the gaseous medium. Sources of information taken into account during the examination 1. USSR author's certificate No. 297674, cl. From 14 to 1/40, 1969. 2. German patent number 243088, cl. 28 to 13, published. 1912.