METHOD FOR MARKING HIDES, SKINS AND SIMILAR SHEET-LIKE MATERIALS

Abstract: For identifying a skin (1) during and after its tanning and processing it may be provided with a binary punch code (2, 8, 9) or a signal code comprising eg. radioactive or magnetic trace elements. The holes (2, 8, 9) as well as the trace elements are through-going for preserving the code intact in any split skins (3) made thereof. At its beginning and end the code is provided with a reference signal (8, 9) that may be used for showing dimensional changes during the processing. The code is moreover made on a line for facilitating the reading thereof which may take place by means of a manually operated measuring carriage (6) which is carried over the code.

Description: METHOD FOR MARKING HIDES, SKINS AND SIMILAR SHEET-LIKE MATERIALS The invention relates to a method for marking hides, skins and similar sheet-like materials. When processing hides, skins and the like the material is usually subjected to a chemicai processing e.g. in connection with tanning, dyeing etc as well as a mechanical processing in the form of splitting, ie. lamination, folding, embossing, punching, cutting etc. The processing proper takes place in a complex flow where raw skin lots are being worked up. This is not always in parallelly running production lines because according to requirements some objects are being col¬ lected in intermediate stocks and others are being partially processed. At the same time a grading as to quality, dimensions etc takes place into a number of different lots. During such processing there is a requirement for being able to relate a given sk,in or a given lot to a defi- nite delivery of raw material or to a definite prod¬ uction process since by deviations from the norm it is absolutely necessary to intervene quickly to be able to correct the process or processes causing the de¬ viation. With a view to economy and quality it is therefore desirable that the individual skin can be identified at any time during the process. Various types of identification for marking skins are known. Usually the required data are pressed or embossed into the skin surface by means of a die for identifi¬ cation purposes. Each individual skin, however, must be embossed which means that in practice split skins must be embossed after the splitting which is trouble- some and inexpedient. There is moreover a considerable risk of wrong marking of the individual skins since it may be difficult to read and control the marking during the production process. Furthermore, an em¬ bossing is easily destroyed or blurred during the processing and so consequently difficult to read. It is the object of the invention to remedy these drawbacks by the known marking of skins and this is achieved by a method where the material is provided with a code extending through the entire thickness of the material and which remains unchanged in any split parts thereof. In this way it is ensured in a simple and inexpensive manner that any marked skin at any stage of the production process can be iden- tified and so related to a given raw skin or finished article made thereof. A single coding is therefore sufficient because this coding is permanent through the entire thickness of the skin. This substantially simplifies the marking while at the same time in- creasing security against wrong marking. By making holes in the skin as disclosed in claim 2, the coding may be performed by a simple punching of small through-going holes and by means of optoelec- tronic measuring instruments and light through these holes the punch code can be read in a reliable and simple manner. By using through-going signallers as disclosed in claim 3 > it is possible by means of suitable reading instruments to read the code in a similar manner with¬ out having to perforate the skin. By using magnets such as plastic magnets as signallers as disclosed in claim 4, the code may be read with a simple measuring instrument. By beginning and ending the code with a reference signal as disclosed in claim 5, compensation may be made for any deformations occurring chemically or mechanically during the processing of the skin. Finally, it is advantageous that the marking is on a straight line as disclosed in claim 6, since the read¬ ing becomes more reliable because deformations may occur in several planes and directions. The invention will be further described in the follow- ing with reference to the drawing, wherein Fig. 1 is a top view of a skin after the coding, Fig. 2 is an enlarged cross-section of the skiri" seen in the direction II-II in Fig. 1, and Fig. 3 is the skin placed in a reading apparatus. The method will be described by a preferred embodiment shown in Figs. 1 and 2 and which consists in coding the skin 1 by means of through-going holes 2, 8, 9. As will appear from Fig. 1, a line of holes 2 has been OMPI 4Λ„ WIPO made in a skin at one of its corners. These holes may of course be placed at any other place of the skin where they cause the least inconvenience. The holes are preferably punched in the skin by gen¬ erally known means, ie. punching tools, mechanical boring, hole burning and the like. In the shown example the code itself is built up as a binary punch code wherein a hole means logical 1 and no hole logical 0. By using this punch code each individual skin may be marked with ia. a serial number and a date number. Moreover, it is possible to encode eg. the right or left side of the skin but any desired piece of information can be encoded in this manner. At the beginning and end of the code there is encoded a reference hole 8, 9 being arranged at a given mutual distance. It is thus possible at a later date on read- ing the code to show any deformation in the logitu- dinal direction thereof. As will appear from Fig. 1 all holes 2, 8, 9 are placed in a straight line thus facilitating the en- coding as well as the subsequent reading of the skin since the reading is easier along a line that at this time may deviate from a straight line. Fig. 2 shows a cross-section of a hole 2 and the dot- ted lines moreover indicate that the skin 1 by being split can be split in a number of parts 3 that will all contain the given punch code. Fig. 3 shows an embodiment of a reading apparatus O PI comprising a light table 4 with a light cabinet 5. The skin 3 is placed on this light cabinet so that light can penetrate the punch code 2, 8, 9. By means of a generally known optoelectronic measuring carriage 6, the carriage can be carried manually over the punch code. The carriage 6 has- a decoder for measuring the dis¬ tance between the individual holes in the code. The • measured distance between the reference holes 8, 9 is compared by means of a calculation program with the original distance between these holes 8, 9« Any pos¬ sible deviation is used for correcting the longitu¬ dinal deformation that may have occurred during the processing of the skin. Photocells in the measuring carriage 6 are activated and the signals processed and stored by means of a data program. By means of an additional keyboard 7 which may be mounted on the table 4, it is possible to store information such as lot number, grade class, tanning process etc. The date read and stored in this manner can in a generally known manner be stored on magnetic tape, floppy discs and the like from where. said data can be transferred. The described method can also be performed by means of other than a punch code. By using radioactive or mag¬ netic trace elements that can either be embedded by pressing in a rod or be injected by means of a solu¬ tion, it is possible in a similar manner to mark skins and read the code by means of a generally known suit¬ able apparatus.

Claims: P A T E N T C L A I M S 1. Method for marking hides, skins and similar sheet¬ like materials, c h a r a c t e r i s e d i n that the material (1) is provided with a code (2, 8, 9) extending through the entire thickness of the material (1) and which remains unchanged in any split part (3) thereof. 2. Method according to claim 1, c h a r a c t e r ¬ i s e d i n that the coding is performed by making a number of through-going holes (2, 8, 9) in a pre¬ determined pattern. 3. Method according to claim 1, c h a r a c t e r - i s e d i n that the coding is performed by intro- ducing a number of through-going signallers in a pre¬ determined pattern which signallers are cut when splitting the material (1). 4. Method according to claim 3 » c h a r a c t e r - i s e d i n that the coding is performed by intro¬ ducing a number of through-going magnets in a pre¬ determined pattern which njagnets are cut when split- ting the material (1). 5. Method according to any of the preceeding claims, c h a r a c t e r i s e d i n that the code begins and ends with a reference signal (8, 9). 6. Method according to claims 1-5, c h a r a c t e r- i s e d i n that the code (2, 8, 9) is placed on a line.

Inventors: AOHLUND CHRISTER, AOHLUND, CHRISTER
Applicants: NORDISK LAEDERFORSKNINGSRAOD T, NORDISK LAEDERFORSKNINGSRAOD TEKNOLOGISK INSTITU
Application year: 1984
Main classification: C14B1
IPC codes: C14B1