CA1335936C - Label - Google Patents

Abstract

The present invention is directed to improvements with respect to articles which are to be folded about an edge of a substrate. In particular, the invention is useful in multiple layer labels which have a plastic film cover of high tensile strength. These types of labels, when wrapped about the edge of a substrate, have a tendency to return to a less folded condition and thus, the adhesive layer which maintains the label in contact with the substrate must continuously offset this internal force. According to the present invention, this is overcome by structurally weakening the label at a predetermined location during the manufacture of the label to allow folding of the label in this predetermined location. This structure reduces the internal stress forces which tend to urge the label to a less folded condition. The invention also has application with respect to reinforcing films or other reinforcing materials which have a tendency, when folded, to return to a less folded condition.

Description

TITLE: IMPROVED LABEL

FIELD OF THE INVENTION
The present invention relates to improvements in adhesively adhered labels or strip material applied or to be applied about an edge of a substrate and adhered to opposed sides of the substrate. In particular, the invention relates to an improvement which reduces internal stresses normally produced during wrapping of the label or strip material about a substrate edge, such that the resulting product is less prone to separate from the substrate.

BACKGROUND OF THE INVENTION
Reinforcing film for file folders and multi-layered labels for file folders are well known in tne filing art and have had application with respect to repair of file folders and the labelling of file folders, both during the initial manufacture of the file folder for customers or as a post-manufacturing operation carried out by the customers.
Examples of particularly useful reinforcing film and of labels are disclosed in our United States Patents 4,183,779, 4,204,639, 4,240,848, 4,294,644, 4,329,191, 4,588,463 and 4,749,121.
With respect to multi-layered labels, as disclosed above, the outer plastic film cover of the labels have a relatively high tensile strength to provide protection to the label and have proved particularly satisfactory in the marketplace. As can be appreciated, a label which is applied about the edge of a substrate is exposed to excessive wear, and particularly the portion of the label covering the edge of the substrate is particularly prone to wear. The reinforcing films used with these labels have proven particularly satisfactory and do not normally suffer from damage due to this demanding environment. Labels of this type typically use a pressure sensitive adhesive which secures the label either side of the substrate. The portion -about the edge of the substrate is continuous.
Unfortunately, the excellent wear characteristics of the plastic film introduces an additional disadvantage in that this plastic film tries to separate the label from the substrate to relieve internal stresses created during the wrapping of the label about the edge of the substrate.
These internal stresses are opposed by the adhesive bonding of the label either side of the substrate which during original application are more than sufficient for maintaining the label. Unfortunately, witn aging of the adhesive and exposing the labels to abuse, some labels may partially separate from the substrate due to these internal stresses which overcome the reduced adhesive force on a section of the label. Once the label is partially separated, it is then extremely prone to full separation. Therefore, the desirable high wear characteristics of the plastic film introduce the disadvantage of the internal stress forces of the label urging the label to at least partially separate from the substrate to which it is applied.
Attempts to use better adhesives or possibly using a nonpressure sensitive adhesive have not proven entirely satisfactory and the convenience of a pressure sensitive adhesive for applying labels, particularly in a retrofit application, has led to this type of system being necessary.
There remains a need for providing a reinforcing film or label which is desiyned to be applied to either siae of a substrate and about the edge of a substrate which has the desired high wear characteristics, but does not develop the high internal stresses which tend to cause labels to separate from the substrate during the passage of time. It must be appreciated that colour coding systems of the type referred to in the above patents often have files with a life of ten years or more. Colour coding systems essentially read the edge of the file folder as opposed to the indicia along the sides of the substrate and removal of a label defeats this purpose entirely.

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SUMMARY OF THE INVENTION
A reinforcing film or a label for application about the edge of a substrate and in adhesion with either surface of the substrate, according to the present invention, is improved by having in the area which is to be applied about the edge of the substrate a structurally weakened area produced during the manufacture of the substrate which permits both the convenient folding of the substrate or label about the edge in this weakened area in combination with a structure which develops less internal stress forces which would tend to cause at least a portion of the label or reinforcing film to separate from one of the opposed surfaces of the substrate.
According to an aspect of the invention, the reinforcing film or label is scored on an interior surface of the plastic film, such that the outer surface of the film remains continuous while the interior surface has been structurally weakened and folds readily about this weakened area.
According to a further aspect of the invention, the label or reinforcing film has been scored in parallel lines in the predetermined region which extend generally in the direction of the desired fold and at least four separate score lines are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in the drawings, wherein:
Figure 1 is a partial perspective view of a label applied about the edge and either side of a substrate;
Figure 2 is a sectional view through a label which has been applied about the edge and either side of a substrate;
Figure 3 is a partial exploded sectional view of a label;

Figure 4 is a partial cutaway perspective view of the label; and Figure 5 is a top view of a label partially applied to a substrate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODI~ENTS
The invention is shown with respect to multi-layered labels, however, the same principles are applicable to reinforcing substrates such as the reinforcing films disclosed in United States Patent 4,588,463. In the case of the reinforcing film, the paper layer may or may not be present, however, the film would still include an adhesive layer and a plastic film layer.
The label, generally shown as 2 in Figure 1, is applied either side of a substrate 4 and about the edge 6 of the substrate 4. The label includes the indicia, generally shown as 18, visible to either side of the substrate 4. In colour-coded labels as shown in Figure 4, tne indicia is duplicated to be visible either side of the substrate and the background 19 provided about the indicia also implies a coding significance. This background colour will also be present in the folding region, generally shown as 12 in Figure 4.
The label 2 has a first section 8 and a second section 10 for application to opposite sides of the substrate separated by the fold region 12. The label has a clear plastic reinforcing outer layer 14, a paper substrate having the indicia 18 and 19 thereon identified as 16, and a lower adhesive layer 20.
The fold region 12, as best shown in Figures 2, 3 and 4, has a number of slits 24 through the paper substrate 16 and the adhesive layer 20 with the clear plastic reinforcing outer layer 14 being scored at the internal point 26 of the slits. These slits 24 structurally weaken the high tensile strength film in the folded region, but maintain a continuous outer surface of the film which will remain highly resistant to wear. The structural strength of the label is further weakened by cutting of the paper substrate and the adhesive layer. In the embodiment shown, six slits 24 have been shown in very close proximity, one to the other. The spacing between the slits is constant and the overall width between the outer slits is about 1/4 inch.
The label, as shown in the drawings, exhibits the desired structural characteristics of excellent wearability due to the continuous outer surface of the plastic film 14 in combination with the reduced tendency of the label to try to separate from one surface of the substrate to relieve internal stresses. This tendency of the label has been reduced due to weakening of the label in the fold region and in a manner to maintain the continuous outer surface. In addition to having these desirable characteristics, the label, due to the slitting of the various surfaces and the scoring of the plastic film, is more suitable for the automatic application of the label to a file substrate, as generally shown in Figure 5.
Machines for the automatic application of labels are already known as exemplified in our United States Patent 4,183,779. Although it is desirable to always accurately place the label on a file folder or substrate, it is not always possible due to misalignment of the label on its initial feed substrate or due to the slight shifting of the label during application to the edge of the substrate.
Thus, it can be appreciated that some misalignment of the fold region 12 with the edge of the substrate can occur and problems can result when the label is wrapped about the substrate edge. Some folds may occur in the fold region, thus producing an extended portion of the label which projects from the substrate edge 6. It has been found that the weakening of the fold region in the manner described above provides a forgiveness in wrapping of the label about the edge of a substrate and reduces any fold projections of the label from the edge of the substrate. Thus, a smoother -WH-7807-89 - 6 - 3172~/0078F

wrap of the label about the edge of a substrate is produced and the adhered label, even if it has been misaligned, is not as prone to damage. The weakening of the label in the fold region and making the weakened area oversized relative to the thickness of the edge of the substrate to which it is applied accommodate a margin of error in the application of the label to the substrate without creating the problems discussed above and allows an effective wrap of the label about the substrate edge 6.
The slits, in addition, have been found to maintain the colour of the background 19 about the fold region 12.
This is a result of the outer surface of the paper substrate not being stretched in tension, as the slits accommodate what would otherwise be a compressive force at the lower surface of the paper substrate.
The invention has been described in detail with respect to the label 2, however, the wrapping of a reinforcing film about the edge of a substrate can also be difficult and the problems associated with misalignment are even more common. The weakening of the reinforcing substrate in the fold region achieves the desired result of a continuous outer plastic film having excellent wear characteristics while providing a substrate which is more forgiving and easier to apply automatically. Even if reinforcing films are applied to one surface of a substrate and the substrate and film folded intermediate the width of the film as disclosed in United States Patent 4,588,463, the advantage of less internal stress force can be realized by structurally weakening the film as disclosed above and folding of the substrate and film within this region.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

Claims (5)

1. In a label having a number of layers, said label being of the type for folding at a predetermined location across the label for placing the label about the edge of a substrate, said label at said predetermined location being structurally weakened over a zone during the manufacture thereof to easily fold upon itself, said structural weakening in said predetermined location including structural weakening of said layers whereby the internal stress forces trying to return the label from a folded position to a less folded condition are reduced, said zone being of a width to allow folding therethrough in a non-perpendicular manner to accommodate minor misalignment of a label folded about an edge of a substrate.

2. In a label as claimed in claim 1, wherein the structural weakening in said predetermined area includes a lower surface of said label terminating short of an upper face of said label.

3. In a label as claimed in claim 2, wherein said structural weakening includes a plurality of slits through all layers of the label other than a plastic film top layer which is only scored and wherein said slits extend across the width of the label.

4. In a label as claimed in claim 3, wherein said label includes at least three slits extending across the label.

5. In a label as claimed in claim 4, wherein said label includes at least six slits extending across the label.