Method and apparatus for removing the printed layer of labels from semirigid containers

An apparatus and method are provided for delaminating the top printed layer from a three layer paper label adhesively bonded to a semi-rigid plastic or metal container. An underlying pulp layer of the three layer paper is selectively removed leaving only a smooth adhesive layer of the paper label and thereby providing a smooth unprinted surface for relabeling. An apparatus and method are also provided for simultaneously delaminating both the top printed layer and the bottom adhesive layer of a two layer label bonded to a semi-rigid container.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to label removing and label stripping 
machines of the type adapted to remove printed matter from labels that 
have been placed on semi-rigid and/or flexible containers. 
More particularly, the present invention relates to a novel semi-automatic 
label removing machine which will remove printed matter from labels on 
soft containers without damaging the container material. 
2. Description of the Prior Art 
Heretofore, it was known that printed paper, foil or plastic labels could 
be removed from cylindrical glass containers. My U.S. Pat. No. 4,122,734 
shows and describes a label stripping machine for spirally cutting and 
removing an adhesive label from a glass container which created label 
trash when removing the labels. 
My U.S. Pat. No. 5,152,865 shows and describes a label peeling machine for 
removing both a label and its adhesive layer as an integral unit from 
glass containers. 
The above mentioned label stripping and peeling machines cannot be used to 
remove labels from semi-rigid or soft containers including plastic bottles 
and aluminum containers as the blades used in both of the above mentioned 
machines are hard and would damage the container material. 
It has been suggested that labels could be soaked and then scrapped from 
plastic or aluminum containers, however, problems associated with leaching 
of plastic containers, oxidizing of metal containers and scratching these 
containers have rendered these suggested practices unusable, inoperable or 
not feasible when permanent pressure sensitive adhesives have been 
employed to affix the labels on the containers. 
It would be extremely desirable to provide a method and an apparatus that 
would remove all traces of printed matter from labels to provide a print 
free surface for relabelling when the above mentioned permanent pressure 
sensitive adhesives have been employed with labels placed on semi-rigid 
containers as well as rigid glass containers. 
SUMMARY OF THE INVENTION 
It is a principal object of the present invention to remove the entire 
printed surface of a label applied to a soft or semi-rigid container. 
It is a principal object of the present invention to remove the entire 
printed surface of a printed label and substantially all of the pulp layer 
of a three-layer paper label, leaving a surface acceptable for 
relabelling. 
It is a principal object of the present invention to remove the entire 
printed layer and the entire adhesive layer of a two-layer plastic label. 
It is a principal object of the present invention to remove the entire 
label and adhesive of an overlapping wrap-around label after being slit 
with a tool. 
It is a principal object of the present invention to remove at least the 
top printed layer of an adhesive label from a container and to store it 
for future verification of removal. 
It is a principal object of the present invention to apply a predetermined 
amount of heat to a label having heat-sensitive adhesive to soften the 
adhesive to facilitate removal. 
It is a principal object of the present invention to apply heat to a 
heat-sensitive overlapping wrap-around label to cause it to shrink while 
on the container so as to expose the container surface between opposing 
edges of the shrunken label. 
According to these and other objects of the present invention, there is 
provided a novel method and apparatus for removing the printed layer of a 
label on a rigid or semi-rigid containers. The method comprises 
positioning the label on the container to be removed juxtaposed a 
delaminating adhesive tape and pressing a pressure pad against the back of 
the tape forcing the adhesive side of the delaminating tape against the 
printed label and simultaneously moving the container relative to the 
delaminating adhesive tape with a force applied thereto to simultaneously 
transfer the label material from the container to the delaminated adhesive 
tape.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In my U.S. Pat. No. 5,152,865 it was explained that paper and plastic 
labels having permanent pressure sensitive adhesives could be successfully 
removed from glass bottle containers. When such labels are placed on 
semi-rigid containers such as plastic containers or aluminum containers 
there is no safe, economical or practical way to remove the label without 
damaging the container. 
Refer now to FIGS. 1 and 2 showing isometric drawings in schematic form of 
a preferred embodiment apparatus for removing the printed surface layer of 
adhesively bonded labels on semi-rigid containers. The delaminating 
machine 10 is provided with a reel of delaminating tape 11 which passes a 
delaminating station 12 and is taken up on a take-up reel 13. A forcer 14 
comprising a pair of resilient rollers 15 positioned behind the tape 11 
and forces the adhesive side 16 of the tape 11 into engagement with a 
label 49 on a container 50. The tape 11 is despooled from the supply reel 
17 by a pair of pinch rollers 18. The take-up reel 13 is continuously 
driven through shaft 19 by a friction clutch 20 which in turn is driven by 
a pulley 21 and belt 22 driven by shaft 23 of motor M which also drives 
the pinch rolls 18. In the preferred embodiment of the present invention, 
the means for supplying containers is shown as a bottle feed disk 24 which 
supplies semi-rigid labeled bottles to indexing positioner 25, shown as an 
indexing wheel having a plurality of stations for receiving bottles from 
disk 24 via adjustable parallel guides 26. Circumferential guides (not 
shown) retain bottles 40 within their workstations until removed. 
In this preferred embodiment, a first motor drive 27 has a pulley 29 on 
shaft 28 which is employed to drive pulley 31 via belt 32. Shaft 33 is 
vertically mounted on frame 34 and drives pulley 35 and friction drives 
autofeed disk 24. Pulley 35 drives an electromechanical clutch 36 via belt 
37, and when engaged, the clutch 36 drives shaft 38 on which a Geneva 
driver 39 is mounted. The Geneva driver is operable by Geneva gear 41 and 
provides intermittent rotary motion as is well known in the art. Shaft 42 
coupled to Geneva gear 41 imparts intermittent rotary motion to index 
positioner 25. Programmed logic controller 30 provides selectable machine 
operation, timing and sequencing. From the aforementioned description, it 
will be understood that labeled semi-rigid bottles 40, with printed labels 
49 adhesively bonded thereto, are moved from bottle feed disc 24 to index 
positioner 25 which carries bottles to a plurality of workstations to be 
described hereinafter. 
Refer now to FIG. 2 showing a schematic drawing and plan view of the 
indexing positioner 25 showing plurality of work stations. Work station 43 
is located opposite the adjustable parallel guides 26 where bottles enter 
into the indexing wheel or positioner 25. Station 44 is shown as the work 
station for a label slitting device 45 and a hot air blower 60. Work 
station 46 is the main delaminating station where bottles are rotated and 
heated in their work station and the printed layer of the label is 
transferred to the delaminating tape 11 while the delaminating tape is 
forced by forcer 14 into engagement with the label 49. The forcer 14 
comprises an air cylinder actuator 47 and a yoke assembly 48 on which are 
mounted two resilient rollers 15. As will be explained in greater detail 
hereinafter, labeled bottle 50 is rotated in work station 46 as the 
delaminating tape 11 is moved from left to right, while being forced into 
engagement with the label 49 on bottle 50 by forcer 14. This action will 
cause the adhesive side 16 of delaminating tape 11 to lift at least the 
top printed layer as will be described hereinafter. Hot air blowers 60 are 
supplied hot air by generators 59. The hot air softens heat sensitive 
adhesives to facilitate delamination. After the top layer of the label is 
removed, the pulp and/or the adhesive layer of the label is removed. The 
container is electronically scanned at scan work station 51. The scan 
station comprises video camera 52 which will generate an electrical signal 
indicative of the reflective light surface of the container which is 
transferred to microprocessor 53 that has been programmed with sufficient 
information to determine if the quality of label removal desired has been 
achieved. If quality is insufficient, a reject bottle 50 is moved past 
exit work station 54 and on to work station 55 for reprocessing. If 
quality of label removal is sufficient, bottle 50 is moved to work station 
54 and moved by retractable guide 56 actuated by air cylinder 57 into 
accumulator 58. 
Refer now to FIG. 3 showing an enlarged isometric view of a preferred label 
slitter 45 of the type employed at slitter station 44. The label slitter 
45 comprises a air cylinder 61 having a piston rod 62 which imparts a 
radial force to slitter block 63 which is movably mounted on frame 34. The 
slitter block 63 is shown having a vertical mounted air cylinder 64 which 
has a slitter blade 66 mounted on its movable rod 65. The programmed logic 
controller 30 is preferably employed at the slitter station 44 and may 
also be employed to actuate air cylinders 61 and 64 when a slitting 
operation is desired. In the preferred embodiment of the present 
invention, different types of bottles that require slitting are usually 
run at the same continuous operation and each bottle being processed would 
be programmed to have a slitting operation performed on the label. 
Refer now to FIG. 4 showing an enlarged isometric view of a container 50 
having a printed label 49 adhesively bonded thereon. The aforementioned 
resilient pressure rollers 15 are pressed upon the back of the tape 11 
with sufficient pressure to conform the adhesive layer 16 to the contour 
of the printed label. When the pressure sensitive adhesive 16 is selected 
to be of sufficient strength to overcome the bond of label 49, the tape 
adhesive 16 will lift the edge 67 of the label 49 and delaminate it from 
the container 50. Different types of labels will require different 
operations to remove the printed layer, the pulp layer, and in some cases, 
the adhesive layer to be described hereinafter. 
Refer now to FIG. 5 showing a greatly enlarged section taken through a 
three-layer paper label 49 of the type commonly employed on plastic 
bottles with a contiguous layer 68 of permanent pressure sensitive 
adhesive on the back of the label. The printed layer 69 is the top layer. 
The adhesive layer 68 is the bottom layer. The top layer and the bottom 
layer are separated by a pulp paper layer 70.. It has been found that when 
the adhesive bond between the tape adhesive layer 16 is stronger than the 
bond between top layer 69 and pulp layer 70 the printed layer 69 will be 
transferred to the tape adhesive 16 as it passes through the delaminating 
station 46. If the initial delaminating process does not remove all three 
layers shown in FIG. 5, it will at least remove the printed layer 69 and a 
portion of the pulp layer 70. Successive delaminating operations will 
remove substantially all of the pulp layer 70 leaving a smooth unprinted 
surface suitable for subsequent relabelling. 
Refer now to FIG. 6 showing a greatly enlarged section taken through a 
two-layer plastic label of the type commonly employed on plastic, metal 
and glass containers using pressure sensitive adhesives 68. The top 
plastic printed layer 69 usually comprises a strong plastic film such as 
mylar or vinyl which will support printing thereon. The adhesive layer 68 
is of a type that is often employed with plastic films used in the 
pharmaceutical and diagnostic industries. It has been found that the 
plastic layer 69 shown in FIG. 6 can be removed with its adhesive layer 68 
as an integral unit employing the delaminating process described 
hereinbefore. 
Refer now to FIG. 7 showing an isometric view of a bottle 50 with attached 
label 49 of the type shown in FIGS. 5 or 6. Opposing label edges 67 
provide a gap 71 exposing surface of bottle 50 therebetween. An edge 67 
must be lifted to start the delamination process. 
Refer to now to FIG. 8 showing an isometric view of an overlapping 
wrap-around label 72 of the type commonly used on syringes or ampule 
containers 50A employing an adhesive layer 68. The plastic label 72 is 
wrapped around itself and does not provide a gap 71 or edges 67 of the 
type shown in FIG. 7. When such plastic labels are to be removed, they are 
first slitted to form a gap 71 at the slitting station 44 employing the 
slitter device 45. 
When two-layer plastic labels are employed as shown in FIG. 6, and said 
labels are wrap-around and overlapping, it has been shown that shrinking 
with hot air will effectively provide a gap 71. It will be understood that 
the delaminating process starts at label edge 67 whether provided 
initially, or by the slitter, or by heat shrinking. Once delamination 
starts, the complete label 72 can be removed usually in a single 
rotational pass over delaminating tape adhesive 16. 
Refer now to FIG. 9 which shows another preferred embodiment of the 
invention in isometric view wherein labeled container 50 is frictionally 
rotated on adhesive side 16 of delaminating tape 11 by resilient friction 
pad 73 movably mounted on slide plate 74 by rod 80 and cylinder 75. Guide 
pin 76 position pad 73 when actuated downward toward container 50 by 
piston rod 80 of air cylinder 75. Horizontal movement of resilient pad 73 
is caused by retraction of air cylinder rod 77 within air cylinder 90 
mounted to frame 78. It will be understood that the downward resilient 
force of friction pad 73 and simultaneously horizontal movement across 
tape 11 by retracting air cylinder rod 77 of air cylinder 90 causes 
container 50 to rotate the exposed label 49 to tape adhesive 16 on tape 11 
that is supported by resilient pressure plate 79. 
Delaminating tape 11 is supplied by tape supply reel 81 rotatably mounted 
on frame 78. Idler rollers 82 rotatably mounted on frame 78 keep tape 11 
positioned on plate 79. Tape take-up reel 83 rotatably mounted on frame 78 
is driven by belt 85 attached to drive motor Preferably take-up reel 83 
pulls tape 11 from supply reel 81 and positions an unused portion of 
delaminating tape between idlers 82 on plate 79. After completing a label 
delamination operation, the used tape is advanced by motor 84 onto takeup 
reel 83. Hot air generator 88 may supply hot air through hot air nozzle 87 
to soften heat sensitive adhesives 16 and/or 68 prior to delamination. 
Separator plate 86 separates delaminated containers 50 from the adhesive 
on tape 11. Air cylinder 90, air cylinder 75, motor 84 and hot air 
generator 88 are controlled by program logic controller 89 of the type 
explained hereinbefore. 
Having explained a preferred embodiment and a modification of the present 
invention in an apparatus that has sufficient flexibility to process 
numerous types of labels that are placed on rigid or semi-rigid containers 
it will be appreciated that the delaminating apparatus and method 
described hereinbefore will remove from semi-rigid containers numerous 
types of labels which could not be removed before. Thus, the present 
invention permits relabeling of containers which contain valuable 
ingredients which could not be reused before.