Machine readable characters are used for a variety of different applications. Particularly, bar codes are employed in identifying products in stores. In these applications, one number or bar code is applied to all identical articles. The bar codes are almost always printed on the packaging.
Bar codes can also be used as a means for inventory control and identification and location of goods or other articles. This may require a separate bar code for each and every item. This is possible where the bar code is printed on a paper material that has an adhesive backing. This will not work, however, in applications where the bar code must be applied to a cloth substrate which is subjected to an industrial laundry. Mere pressure sensitive adhesives will not withstand any laundering. The extreme conditions of an industrial laundry cause even most heat activated transfers to separate from the article of clothing, delaminate or cause the indicia to dissolve.
A bar code must be clear and sharp. If the bar code or other indicia is not clearly discernible, it cannot be machine read. It also will be very unattractive.
It is possible in many applications to preprint a bar code within a laminant so that separate lamina are on either side of the bar code. These laminae protect the bar code. A problem with this, however, is delamination. Again, particularly with commercial laundry conditions, delamination is an extremely significant problem.
Mahn U.S. Pat. No. 4,610,904 discloses a heat activated transfer having a bar code which does not delaminate. But the bar code must be produced by a screen printing process or similar manner. The bar code may also have to be overcoated with an outer clear layer. This would work if one was applying the same bar code to hundreds of items. But this is impractical for applying a different bar code to each different item.
Thus, for a coded label to function on an item subjected to an industrial laundry, it must withstand the conditions of the commercial laundry. There must also be an effective way to apply the code onto the label. Further, the bar code must not delaminate or fade and must be clear and machine readable.