US3144760A

US3144760A - Surface of suede leather

Info

Publication number: US3144760A
Application number: US183053A
Authority: US
Inventors: Fuchs Hermann
Original assignee: Carl Freudenberg KG
Current assignee: Carl Freudenberg KG
Priority date: 1962-01-30
Filing date: 1962-03-28
Publication date: 1964-08-18
Anticipated expiration: 1981-08-18

Description

United States Patent Offi e 3,144,760 Patented Aug. 18, 1964 3,144,760 SURFACE F SUEDE LEATHER Hermann Fuchs, Weinlieim an der Bergstrasse, Germany,

assignor to Carl Frendenberg, Weinheim an der Bergstrasse, Germany, a German corporation No Drawing. Filed Mar. 28, 1962,, Ser'. No. 183,053 Claims priority, application Germany Jan. 30, 1962 Ciaims. (Cl. 69-'-21) The present invention relates to improvements in the surface of suede leather, and more particularly to the branding of patterns in suede lether so as to impart geometrical designs covering at most about 50 percent of the total surface area of the leather being treated.

Suede leather is known to have many advantageous applications, but these are in part offset by the recognized disadvantages of this type of leather. Such disadvantages are emphasized in the Handbuch der Gerberei, Chemieund Lederfabrication, vol. 3, part 1, page 1104. In this manual of tanning, chemistry, and manufacture of leather, it is stated that a prerequisite for obtaining a satisfactory suede product lies in the selection of leather raw materials free from veins, uniformly blended or shaded, having full streaks, etc. A suede leather having a greasy luster is particularly to be avoided. In view of the fact that in the production of leather only a small portion is found free from veins and blemishes, a great part of leathers used in the production of suede leather must be rejected as waste in the process It is an object of the present invention to overcome the drawbacks previously encountered and to provide suede leather having improved surface properties.

Other and further objects of the invention will become apparent from a study of the within specification.

It has been found in accordance with the present invention that improvements in the surface of suede leather may be effectively provided by a process which comprises hot-compressing leather with a pattern of geometrical designs, each design having a surface area u pto about 1 cm. and the combined area of said designs with respect to the surface of the leather amounting to at most about 50 percent of the total surface area of the leather being treated.

In accordance with the preferred embodiment of the invention, the designs will be discrete from one another and will form a repeating pattern, in some cases more than one discrete design being used whereby the plural designs together will form a repeating pattern. The heat-impressing is generally carried out at a temperature between about 400 and 800 C. without excess pressure.

Thus, the hot-impressing may be carried out in a particular manner by passing the leather along a traveling path and against a rotating hot roller having design impressing raised surface areas to obtain the designs in the leather.

Accordingly, the branding of patterns in suede leather is achieved so as to form a suede leather with improved surface properties, the finished leather having a surface pattern of impressed geometrical designs, wherein each design represents a surface area up to about 1 cm. and the combined area of the design on the surface of the leather amounts to at most about 50 percent of the total surface area of the leather bearing the designs.

Advantageously, the process of the present invention may be applied for the improvement of the surface of suede leathers of various kinds and especially those containing veins therein by simply branding patterns or designs into the leather surface. As aforesaid, the particular pattern or geometrical design may be of any kind, such as a pattern or design in the shape of lines, curves, triangles, rectangles including squares, diamonds, parallelograms, etc., combinations of one or more of these,

etc., such as in repeating patterns, etc. It is only essential for achieving the desired result that the size of an individual pattern does not exceed a surface area of 1 cm. while on the other hand the total surface of all patterns applied to the suede leather surface should not amount to more than about 50 percent of the total surface of the suede leather.

It is surprising that under the foregoing conditions of treatment the qualities of the leather, such as resistance to tearing, flexibility, etc., are not in the least impaired. These results are particularly surprising when it is realized that fat particles present in the leather normally burn or scorch under the application of heat, thus adversely affecting the surface qualities of the product. 'Of course, the ordinary branding process is known for treatment of leather, but in this instance the treatment presupposes the use of hot fat with completely dry leather whereby products are obtained which are used mainly for the greasing of leathers used for driving belts, connecting rotating machine parts, etc. Hence, the temperature of the fat used in treating the leather should not exceed C., since otherwise the most severe damage will occur as may be noted from the Handbuch der Gerberei, Chemi'eund Lederfabricatio'n, volume 3, part 1, page 653. V

In contrast thereto, in accordance with the present invention, a roller may be effectively used for the branding or hot impressing of patterns in the surface of suede leather, the roller carrying in raised form the pattern or design to be transferred tothe leather. Therefore, rollers are used having a pattern or design in the form of relief or elevated portions, whereby upon heating the roller to between 400 and .800? C., the desired branding may be carried out by rolling the hot roller over the piece of leather being treated. A special pressure is not required for the hot impressing of the leather as the weight of the roller is sutficient under the reaction conditions.

Advantageously, not only is there a lack of deterioration of the mechanical properties of the leather, but also, the patterns which are transferred to the suede leather are distinguished therein by extremely sharp contours and contrasts. Such results were not to be expected since the temperature of between 400 and 800 C. exists in the roller, not only along the elevated or raised portions, but also along the recesses or depressions thereof, the raised portions having a surface only a few millimeters radially outwardly of the surface representing the recesses or depressions. In such instance, it would have been assumed that in rolling the embossing or design-empressing roller over a piece of leather that the entire surface of such leather would burn or become scorched by reason of the hot condtion of the roller, or that at least the contours of the branded patterns would be extremely blurred, but such results do not occur in accordance with the invention.

Naturally, in place of the heated metal embossing roller having a temperature of between 400 and 800 C., other embossing means may be used, such as for example even a hot wire which may be simply pressed against the surface of the leather to be treated.

What is claimed is:

1. Process for providing suede leather with improved surface properties wich comprises hot impressing suede leather with a pattern of geometrical designs, each design having a surface area up to about 1 cm. and the combined area of said designs with respect to the surface of the leather amounting to at most about 50 percent of the total surface area of the leather being treated.

2. Process according to claim 1 wherein said designs are discrete from one another and form a repeating pattern.

3. Process according to claim 2 wherein more than one discrete design is used, said designs together forming a repeating pattern.

4. Process according to claim 1 wherein the hot impressing is carried out at a temperature of between about 400 and 800 C.

5. Process according to claim 4 wherein the hot impressing is carried out by passing the leather along a traveling path and against a rotating hot roller having design-impressing raised surface areas corresponding to the designs to be impressed for direct contact with said raised surface areas to obtain the designs in the leather.

6. In the process for providing suede leather with improved surface properties by branding, the improvement which comprises branding suede leather with a pattern of geometrical designs at a temperature between about 400 and 800 C., each design having a surface area up to about 1 cm. and the combined area of said designs with respect to the surface of the leather amounting to at most about 50 percent of the total surface area of the leather being treated, by passing the leather along a traveling path and against a rotating hot roller having design-impressing raised surface areas corresponding to the designs to be impressed for direct contact with said raised surface areas to obtain the designs in the leather.

7. Suede leather with improved surface properties,

having a surface pattern of impressed geometrical designs, each design representing a surface area up to about 1 cm. and the combined area of said designs on the surface of the leather amounting to at most about percent of the total surface area of the leather bearing the designs, said pattern having been made by the process which comprises hot impressing suede leather at a temperature between about 400 and 800 C. with a pattern of geometrical designs, each design having a surface area up to about 1 cm. and the combined area of said designs with respect to the surface of the leather amounting to at most about 50 percent of the total surface area of the leather being treated.

8. Leather according to claim 7 wherein said designs are discrete from one another and form a repeating pattern.

9. Leather according to claim 8 wherein more than one discrete design is used, said designs together forming a repeating pattern.

10. Leather according to claim 9 wherein said designs include at least two of straight line-, curved line-, triangular-, rectangular-, diamond-, and parallelogramshaped designs.

References Cited in the file of this patent UNITED STATES PATENTS 795,359 Moore July 25, 1905 1,657,889 Manns Jan. 31, 1928 2,581,361 Craighead Jan. 8, 1952

Claims

1. PROCESS FOR PROVIDING SUEDE LEATHER WITH IMPROVED SURFACE PROPERTIES WHICH COMPRISES HOT IMPRESSING SUEDE LEATHER WITH A PATTERN OF GEOMETRICAL DESIGNS, EACH DESIGN HAVING A SURFACE AREA UP TO ABOUT 1 CM.2 AND THE COMBINED AREA OF SAID DESIGNS WITH RESPECT TO THE SURFACE OF THE LEATHER AMOUNTING TO AT MOST ABOUT 50 PERCENT OF THE TOTAL SURFACE AREA OF THE LEATHER BEING TREATED.

7. SUEDE LEATHER WITH IMPROVED SURFACE PROPERTIES, HAVING A SURFACE PATTERN OF IMPRESSED GEOMETRICAL DESIGNS, EACH DESIGN REPRESENTING A SURFACE AREA UP TO ABOUT 1 CM.2 AND THE COMBINED AREA OF SAID DESIGNS ON THE SURFACE OF THE LEATHER AMOUNTING TO AT MOST ABOUT 50 PERCENT OF THE TOTAL SURFACE AREA OF THE LEATHER BEARING THE DESIGNS, SAID PATTERN HAVING BEEN MADE BY THE PROCESS WHICH COMPRISES HOT IMPRESSING SUEDE LEATHER AT A TEMPERATURE BETWEEN ABOUT 400 AND 800*C. WITH A PATTERN OF GEOMETRICAL DESIGNS, EACH DESIGN HAVING A SURFACE AREA UP TO ABOUT 1 CM.2 AND THE COMBINED AREA OF SAID DESIGNS WITH RESPECT TO THE SURFACE OF THE LEATHER AMOUNTING TO AT MOST ABOUT 50 PERCENT OF THE TOTAL SURFACE AREA OF THE LEATHER BEING TREATED.