Background of the Invention
Field of the Invention
[0001] This invention relates to linerless labels, and to methods of making linerless labels.
Brief Description of the Prior Art
[0002] In a prior art method of making linerless labels a longitudinally extending label
web was perforated at longitudinally spaced transverse lines to provide lines of perforations.
The underside of the label web was printed with registration marks. The underside
was thereafter coated with pressure sensitive adhesive. Thereafter, a release coating
such as silicone was applied to the face side of the label web. During the manufacturing
process especially when the label web was under tension, the holes formed by the perforations
would open up and the adhesive would migrate from the underside through the holes
and would adhere to the cut edges at the perforations. Following silicone coating,
the label web was slit into narrow label webs which were then wound into rolls. When
the label web was subsequently unwound from the roll, the adhesive that migrated into
the holes caused the web to unwind unevenly, in a jerky manner, which affected print
quality when the web was printed.
SUMMARY OF THE INVENTION
[0003] It is a feature of the invention to provide an improved linerless label web and an
improved method of making a linerless label web.
[0004] In accordance with a specific embodiment of a linerless label web of the invention,
there is provided a longitudinally extending web of label material having a face side
and an underside. There are longitudinally spaced laterally or transversely extending
lines of perforations across the web, and the perforations have cut edges and through-openings
at at least some of the perforations. There is a coating of pressure sensitive adhesive
on the underside of the web. A release coating on the face side of the web preferably
coats the entire face side including the fibers at the cut edges. After slitting the
web into narrow webs, the narrow webs are wound into rolls. As the web is subsequently
being used from the roll, typically in a printer, the convolutions of the web are
paid out from the roll. The adhesive on the underside of one convolution adheres releasably
to the release coating on the underlying convolution. Because the cut edges of the
web were coated with the release coating and the adhesive was applied to the web after
the perforations were made, release of the web from the roll is enhanced.
Brief Description of the Drawings
[0005]
FIGURE 1 is a side elevational view of a linerless label web in roll form in accordance
with the invention;
FIGURE 2 is a diagrammatic side elevational view illustrating a method according to
the invention;
FIGURE 3 is a top plan view of the label web along line 3―3 of FIGURE 2;
FIGURE 4 is a bottom plan view of the portion of the web shown in FIGURE 3;
FIGURE 5 is a sectional view taken along 5―5 of FIGURE 2; and
FIGURE 6 is a sectional view taken generally along line 6―6 of FIGURE 2.
Detailed Description of the Preferred Embodiment
[0006] With reference to the drawings, there is shown a roll R of a wound-up web W of linerless
labels L. As shown, the web W has wraps or convolutions 9, one upon the other. The
web W extends longitudinally as shown in FIGURES 3 and 4 for example and has a face
side 10 and an underside 11. There are longitudinally spaced laterally extending lines
of weakening caused by perforations 12 across the web. The perforations 12 are preferably
made by spaced knife cuts 13 separated by uncut portions or lands 14. Thus, a label
L can be manually torn from the remainder of the web W. There is a coating of pressure
sensitive adhesive 15 on the underside 11 of the web W. The adhesive 15 is preferably
in a uniform coating, however, the coating 11 can alternatively be of the patterned
type. There is a release coating C, typically a silicone coating, on the face side
10 of the web W. There are registration marks 16 printed directly on the underside
of the web W. The marks 16 are disposed between the web W and the adhesive 15. The
adhesive 15 is preferably transparent or at least translucent.
[0007] With reference to FIGURE 2, there is shown diagrammatically a method by which the
linerless web roll R of the invention is made. A wide web W' of label material is
fed between a printing roll 17 and a back-up roll 18. The printing roll 17 prints
the registration marks 16 on the underside 11 of the web W' in a longitudinal and
transverse pattern. From there, the web W' passes between a perforating roll 19 and
a back-up roll 20. The roll 19 makes the transverse lines of weakening, specifically
perforations, across the web W'. From there the web W' passes between a release coating
roll 21 and a back-up roll 22. The release coating roll 21 applies the release coating
C to the face side 10 of the web W'. From there, the web W' passes between an adhesive
coating roll 23 and a back-up roll 24. The adhesive 15 is thus applied to the underside
11 of the web W', however, if desired the adhesive 15 can be applied over the release
coating C. From there, the web W' is slit into narrow label webs W as the web W' passes
between a slitting roll 25 and a back-up roll 26. From there the narrow webs W are
wound into the rolls R.
[0008] It is seen in FIGURE 5 that the perforating roll 19 makes spaced apart cuts 13 in
the web W'. In a typical production environment, the depths and widths of the cuts
can vary substantially. When the perforations are being cut, as by the perforating
roll 19, some of the cuts 13 may be completely through the web W to provide openings
10'. Other cuts 13 may terminate short of the underside 11 and provide to a heavy
score, and even in this event the cuts 13 may open up to provide openings 10' later
in the production process due to web tension. In all such cases, there are exposed
uncoated fibers at the cut edges. In the present invention, the release coating C
covers the cut edges 27 and 28. Adhesive "cold flow" can occur when the web W has
been wound into roll R. Such cold flow causes the adhesive 15 to flow into the cuts
13 including openings 10'. Because the cut edges 27 and 28 have been coated with the
release coating, the adhesive 15 on the underside of one convolution of the web W
releases more easily and smoothly from the cut edges of the underlying convolutions
during unwinding of the roll R. This is conducive to the web W unwinding smoothly
from the roll R during any subsequent processing and/or printing. A typical printer
for printing on the face side 10 of the web W is disclosed in U.S. patent 5,486,259,
assigned to Monarch Marking Systems, Inc. By applying the release coating C before
the adhesive 15 is applied as depicted in FIGURE 2, the adhesive 15 can only releasably
adhere to the coated cut edges 27 and 28.
[0009] Other embodiments and modifications of the invention will suggest themselves to those
skilled in the art, and all such of these as come within the spirit of this invention
are included within its scope as best defined by the appended claims.
1. Method of making a roll of linerless labels, comprising the steps of: providing a
longitudinally extending web of label material having a face side and an underside,
perforating the web along longitudinally spaced laterally extending lines across the
web, wherein the perforating step results in exposed cut edges and in through-openings
at at least some of the perforations, thereafter coating the face side of the web
including the exposed cut edges with a release coating, thereafter coating the underside
of the web with pressure sensitive adhesive, thereafter winding the web into a roll
having convolutions, and wherein the adhesive on the underside of one convolution
adheres releasably to the release coating on the underlying convolution.
2. A roll of linerless labels, comprising: a longitudinally extending web of label material
having a face side and an underside, longitudinally spaced laterally extending lines
of perforations across the web, wherein the perforations provide cut edges and through-openings
at at least some of the lines of perforations, a coating of pressure sensitive adhesive
on the underside of the web, a release coating on the face side of the web and coating
the cut edges, the web having been wound into a roll having convolutions, and wherein
the coating on the cut edges enhances the release of one convolution from the underlying
convolution when the roll is being unwound.