CA1220764A - Self adhesive labels and the manufacture thereof - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A method for applying adhesive labels to articles whereby labels continuously joined to each other and having adhesive on one side are fed continuously to the nip of two co-operating and continuously rotating rollers which act as a severing station to sever the labels in sequence. The cut labels are then held to the first roller by applying a vacuum through the circumference of said roller, and transported by the first roller to an appli-cation station whereby the labels are pressed onto articles.

Description

~2~0764 1 This is a divisional of applicati~n serial number 417,832, filed December 15, 1982 This invention relates to self adhesive labels and the manufacture thereof, and in particular concerns labels which are supplied in roll form. The labels will ma:inly be for application, using suitable machinery, to indivi-dual articles or objects and to this end the invention also provides a method of and mean~ for applying labels to articles or objects, or the labels may simply be for detachment individually by hand as is the case when labels are provided, for example, for office use.
It is in fact in the field of produce marketing that pressure sensitive labels find widest application be-cause, for example, in supermarkets and other stores the products on sale are typically priced by means of a small pressure sensitive label which is applied to the product, and frequently these labels have to be changed because of price change, making cons~ption of: the labels enormous Also, huge quantities of labels which are applied to con-tainers such as bottles and cans are used, an indeed there are many areas of application for pressure sensitive labels Typically, pressure sensitive labels are mounted on a carrier or backing web which is normally a web of paper coated with a suitable release material such as a silicone compound. The adhe:;ive labels are applied to this carrier or backing web for transportation, storage and utilisation, but the labels can readily be peeled from the backing web as there is much a stronger bond between the adhesive and the material of the label, than between the adhesive and the release material . .

iZ~ 4 Not only is the ba~kin~ web superfluous after the labels have been peeled therefrom and consu~ed, but the manufacture of the backinc~ ~eb is a specialist process, and must be performed under carefully controlled 05 conditions The equipment to produce the backin~ web is expensive, and is extremely large, so that only a very few companies are able to finance and perform the backing strip manufac~ure~ rl~hi~ ari~es due to the fact that the release material ~hen applied to the backing 10 paper is largely absorbed by the paper (bein~ a fibrou~, ab~orbent material), and considerable quanti~ies must be applied and in carefully controlled conditions in order to achieve an outer surface layer of the release coat m~t~rial which will perform the required unction. 'rhe relase coat material is a polyerisa~le ma~erial an requires ~o ~e- h~ated after application ~o the paper. The heating time, in order to polymerise the material i~ re~ated to the cluantity applied, and ~ecause of the absorbency of the paper we~
20 a long period of heatiny is required to produce the finished product.

'rhere have been proposals to eliminate the backing strip in adhesive labels, ~ut such proposals h~ve not 25 met with any commercial success. One o~ tbese proposals as set fortil in U.S. Paten~ blo. 3,575,7~
wherein a backless roll of lab~ls is produced by printiny on clay coated paper on one side with ~ nitro cellulose base ink, and ~y coverin~ the ink with a hea~
- cured ther~lo ~etting silicone resin rele~se coating, tbe other side haviny a pressu~e sensitive adhesive appliea thereto. 'lhe silicone release coatin~ is cured at a temperature of 350~ to 500~.

At such tcmperatures, there would be a considerable tendency for the paper to wrinkle, and i.t i~ believed that for this reason, this proposal ila~ not reached ~: "
' .

.

, -` ~ZZ()764 commercialisation. In any case, the extra step of applyins the nitro cellulose ink increa~es the plant size, time o~ production and cost of production. ~or whatever reason other proposals ~or backless labels do 05 not appear to have been commercialised, because ther~
are no backless pressure sensitive labels on the market.

The present invention is concerned with novel fornls of pressure sensitive labels, and with a method for producin~ pressure sensitive labels which adapts itself to the utilization of relatively simple and relatively small dimen~ion machiner~, enablincJ ttle in~house production of pressure sensitive la~els by the manufacturer~ of the basic substr~te m~teri~l. Such a manu~acturer ~ypica~1~ is re~erred to as a "convertor"
in that he conver~s the raw material into sheet~ and webs. The invention also relate~ to machiner~ for producin-J the labels ar~d a method of and means for applyins of such labels to produ~ts.

Accordiny to a first aspect of ~he invention there is ~rovided ahesive labels in roll form deflned by a web of non-porous material which is substar ially non-etensible, said web having at one side ~' the we~ apressure sensitive~ adhesive an~ havin~ at the other side o~ the web a pressure sensitive ad~lesive release coatin~3 w~ereby the web can be rolled up without the nee~ for a bac~iny strip.
The u~e o~ a non-porous web preger,t~ the considera~le advantage that when the release coating is a~plie~
thereto, it can be ap~lied in relatively small amounts, which means that the curing tilne for the release coatin~ is reduced, and lower curing temperatures (~s compared to the curing temperatures used in U.S. Patent t~lo. 3,575,7~8 can be uscd). ~1oreover, it i5 not ~Z~ ;4 necessary to apply a nitrocellulose base inl~ to the web bef ore ap~lication of the release coating.

It is preferred that the web s~lould be other than OS cellulose fibre based as cellulose fibre webs have the disadvantages as aforesaia.

The web is preferably o a relatively norl-eY.tensible material so as to enable the individual labels to be cut therefrom.

The pressure sensitive adhesive may cov~r the entire surface area or parts of the surface area which in certain cases minin~ises the risk of the pressur~
~ensitive a~hesive being ~ueezed from the coil of la~els to interrere with the unwin~ing of ~he w~b and can increase the ~ase with whi~h the ~e~ of la~els can be applie~ t~ the ~roduct. Preerably, the ~7eb is. die cut to ~e~ine individ~al labels therein and the release coatiny i~ applied over the cuts to provide eY~tra retention ~trength holdiny the labels toyether or to the remainder of the web The perforation~ or other lines of weakeniny causea by the die cuttincJ may define the l~bels so that wh~n the labels are removed from ~he web there rem~ins a skeletal wa6te of the web Illaterial, but it is also within the scope of the invention that the perforations or other lines of weakening should be arranged so that the entire web area defines l~b~ls, ~tith no ~urplus.

The web ll~ay be ~rinted to define the labels, the printin~ being on the side of the ~eb to ~J}liCh the release coatiny is a~lied. Prefera~ly, the ~e~ is ~f a synthetic resinous material contairinc~ an inorganic filler ~uch as talc or chalk.

lZ~()764 According to another aspect of the invention there is provided adhesive labels in roll form comprising a ~eb o~ base material, a pressure sensitive adhesive on one side of the web and a pressure sellsitive adhesive 05 release coating on the other side so that the ~leb cc~n be rolled up without the use of a backing strip, the web havincJ defined therein, by die cutting or t~le like, individual labels, which can be individually detached from the roll, and by virtue of ~he adhesive, attache~
to articles to be labelled, In this aspect of'the invention, the web may be fibrous or non-fibrous, the novel feature beiny that the web has individual labels defined therein ~or removal therefron~, each having pressure sensitive adhesive on one side and release coating material on the other web.
Preferably, the release coatiny i5 a~plied to the web after the die cuttin~ or the like, so th~t the release coating fill~ the cuts to lessen the tendency o~ the labels to detach from the web as unrolling of the web is taking place.

Also, according to the invention there is provided a method of manufacturing labels wherein a web of non-fibrous material which i5 relatively inex~ensible isprinted to define individual labels therein, ~ pressure sensitive adhesive i5 applied tb one sic'le o~ ~he weh and a pressure sensitive adhesive release coating is applied to the other side of the web so that the web of labels can be rolled up without re~uiring a bac:kin~
strip, the adhesive and release coating ~eing subjected, if necessary, to tr~atment to dry/and cure the same before rollincJ the ~ into roll form.
.
Preferably also, the release coating is a heat curable material, and the web is passed through a hot air oven at a tem~erature of 110C to cure the release coating.

~IJ';'t;4 It is ~referred that the web ~hould travel in a continuous path through a release coating stationt a release coatiny curiny station, an ~dhesive application station and an adhesive drying station, but not ~5 neccessarily in that order.

According to yet a further a~pect of the invention there is provided a method of app~ying labels ~s aforesaid to articles wherein the web is advanced to a unit operating in synchronisn~ with the feed of articles to which the labels are to be applied, said unit taking labels one by one from the web and applying same to the moving articles.

The web material defininy the labels will be of ~
~hickn~ss consis~ent with th~ tnickncss of the la~els as conventionally used and Jnay ~e provided ~lith sprocket fee~ holes at the edge~ tnereof.

20 For t~e application of the labels which are defined in the web and are reînovable from the ~7eb to leave a ~keletal waste, there may be an applicator arran~ed to punch a portion of the label from the ~leb to cause that portion to adhere to the appropriate article, and the article and we~ are r~latively movable from this position so that the relative movement causes the remainder of the label to be removed fr~m t~le web.

Where the said labels are defined by perforations, these may be such as to leave sufficient "catchpoints"
between the label and the remainder of the web so ~hat the label will remain in position of the web until such times as it is forceably removed or dis~ ced therefrom. The leading edge of the label, which is first attache~ to the product or article may be free of such catch points so that it will deflect readily out of the web to sin~plify application.

~ 7 -1 The release coating may be applied to the web b~ rollers~
gravure cylinders or hot melt applicators to provide a surface having a release characteristic. The coating may for example contain non-migrant repellants, and in par-ticular, polymerisable silicone polymers. The coating may for example be a soluent heat cured coating, an aqueous system, solvent free or W cured, examples of the above are as follows:

Solvent Heat Cured A) Silcolease* ~TM) 425 (30~) (ICI~ 100 parts by weight Catalyst 62A (ICI~ 4 parts by weight Catalyst 62B (ICI) 4 parts by weight Toluene 200 parts by weight 15Curing Time at 120C 10 seconds 100C 15 seconds 90C 20 geconds Dry of solvent prior to cure approx. 5 seconds.
B) a) Sylo* 7046 Basic polymer dispersion.
b~ DowCorning* 7047 Curing agent or Q2-7046*.
a~ and b) are used in ratio o 10:1 typically.
c) Q2-7090* ~Dow Corning) Premium release additive. Is used in varying proportions to lower release levels o basic Q2-7046*.
d) Q2-7089* ~Dow Corning) Release modifying ' ~ *Trade Mark ,, , ' ' ~u~

d) Q2-7089 (Do~l Corning) Rele~e ~nouifyiny ~gent. C~n b~ us~d in varyincJ amounts to L~i~e1eve lo f releas~ of Q2-7046 05 and give~ ~table modified relea~e levels.

e) Q~-7127*lDow Corni.ng) ~ccelerator for ~2-7046. Is wsed in ~ninute cluantities to ~ccelerate the cure rate of ~2-70~6.
Especially u~e~ul or lowte~hperature curin~ on su~trates such as ~olyethyl~ne film.

20 f) Syloff 297 (Dow Corning~ Anchorage ad~itive.
~ecess~ry to provioe a~rasion r~si~tance for off-line worl.
~xce~t u~ing P~K).
In the following proportiorl~ by vol~me.
3 1 4 5 r ~ i Syloff 7046 20 20 1~ 16 13.~
Crosslinker 7047 2 2 1 2.2 3.2 Q2-7090 _ _ _ _ 2 Q2-70~9 _ _ _ ~ _ Q2-7127 _ _ 0.0~ _ 0.0 SylOL L 297 _ 0.2 _ 0.2 ~olvent 7~ 1 7~ ~9 ~0 ~2 ,~,. _ .
~ * Trade Mark )'7~4 _l - Stclnclclrd bat~- for in-line use or of~-line on cert~in ~;ubstrates such as PI~K.

~t~_~ - Standard bath for o~f-line use, usincJ Syloff 297 anchorage additive.
()~
~5~_3 - Special 10~7 solids batl~ or coatiry ~ilr,s such as polyethylene. Solvent choic~ important ~nd ethyl ~cet~te be~t. Uses Q2-7127 as _ accelerator.
- Controlled release bath. Features Q2-70S9 as release modifier and Syloff 2g7 as anchorage additive.

B~t~_5 - Premiul.l release orlllulatior~ involvin~
incorporation ~-7~gO low visco~ity fluid ~nd a~ditional ~2-7127 to res~ore catalyst level.

T~lese ~re only typical baths and l~vel~ o~ accel~rator, release modi~ier and premium release additivc- can all be varied to satis~y custonler d~mands.

ÇU~ Çll~ ;iQD ';
~5 Bath 1 alld 2 cure in 8-12 seconds at 140C dependin~ on substr~te nature.

Bath 3 will cure in 1~-20 seconas ~t 7~C, ~at~ 4 cures typically in 15 seconds a~ 140C.

Ba~ 5 cures irl 30 seconds ~t 100C or 1~ seconds at 140C.

Q~ y~tg~

A__&__~__ SYL OF~ 1171* (50%) (Dow Corning) Organopolysiloxan~ 14 parts by weiyht.

C.M.C. (Carboxy methyl cellulose) 2 parts by weiyht.

Catalyst 1171A*(Dow Corning3 Orgarlo tin Acylate 1.4 parts by weight.

or Catalyst 164* (Dow Corning) Organo-tin ~ercaptoacet~te 3.5 parts by weight.

Water To ~ive 100 ~arts b~
wei~ht.

Cure tilile 10 seconds at 120C

~Qlyg~ L~ icQ~g A) Syloff 7044 S100%) SDow Cornin~) 100 par~s by weight.
Crosslinker 7048 ~100%) SDow Corning) 4 parts ~y 2S weic~ht.

B) Coating Q2-7069 SloO~) SDow Corning) 1~0 ~rt~ ~j weight .
Crosslinker 704~ (100%) ~Dow Corniny) 4 ~art~
weight.

Cure time A) 40 seconds at 120C 10 seconds at 170C.
B) 3U seconds at 170C
3~ -* Trade Mark lZZ~J76~ ' ~_Ç~e~

A) Silicone Dehasiv VP 1502 (100~) (Wacker) 100 parts by weight.
05 Crosslinkiny Agent VP 1503 (100~ acker) 4 parts by weight.
Catalyst OL (100%) (Wacker)0.4 parts by weiyht.

10 B) Silicone X-62-7004 (100%) (Shin-Etsu Chemical Co.
Ltd) 100 parts by weight.
Catalyst X-92-095 (100~ tshin-Etsu Chemical Co.
Lt~) 10 parts by weight.

Cure rate 0.6 secon~s with high pressure n-ercury ~apour U. V l~mp ~160 W/c~,).

The amount of release coating applied may be in th~
order of 0.1 to 1.5 grams/sq. metre depending upon the web. The pre~sure sensitive adhe&ive Jnay be applied by conventional means~ and typicallay may be a ~olvent or water based emulsion of which the solvent or water is dried from the web after application. The ~ressure sensitive adhesiv~ may ~or example be hot melt, water based, or 501vent ba~ed, example~ of which are as follow~:

~QS~

309 Elvax *40-P (Du Pont) (Ethylene-vinyl aceta~e resin) 40 parts by weight.
. , Piccovar* L-60 (Hercules Inc.) (Hydrocar~on resin) 60 parts by wei~ht.
Irganox *1010 (Ciba Geiyy) (~ntioxidant) - 0.5 parts by weight.
* Trade Mark Q~

Indatex SE2229S (Industrial Adhesives Ltd) fi~lye~t Vinalak*5150 (Vinyl Products Ltd) The labels may be colour printed by any suitable rnetho~
such as letter press, flexoyraphic, gravure or of~set litho.

For the web material, it is preferred to use ~olypro~ylene or high d~nsity polyethylene filln, including substan~ial propor~ions o~ particulate inorganic material.

Typically, the inorganic material may be included in the range 20 to 50% o~ the web by volume, and in the preferred case the web is polypropylene ethylene sequential copolymer, a~ de~cribe~ in our British Patent ~o. ~1544,143) filled with 40~ talc.

~mbodiments of the present inven~ion will no~7 ~e described, by way of example, with reerence to the accompanying diagrammatic drawings, wberein:-Fig. 1 is a perspective view of ~ roll of labels according to the present invention;

Fig. 2 is an enlarged seçtional elevation of th~ we~shown in Fig. l;

Fig. 3 illustrates diagrarnmatically one en~bodirnent of how the labels are a~plied to individual cans;
- * Trade Mark Fig. 4 ~hows the process of Fiy. 3 in side elevation, ~ig. 5 S}IOWS a roll of labels accordiny to a second en,bodiment of the invention;

Piy~ 6 shows in perspective view how a roll of la~els is u~ilised in accordance with ~nother aE)se~ct o~ the invention;

E'i~. 7 illustrates how the labels of Fig. 1 are applied - to box shaped products;

~ig. 8 illustrates apparatus ~or the coatiny of the web oE lab~ls with pres~ure se-lsitive adhesi~e and release 15 coating accordin~ to one r.l~thod;

Fiys~ 9 ~nd 10 illustr~e appar~us ~or the said coatincJ accordin~ to two other m~t~lods, and Fig. 11 illustrate~ apparatus which is a modilication of the Fig. 10 apparatus.

Referriny firstly to Figs 1 to 6 of the drawincJ~, in Fig. 1 there is shown a web 10 having perforations 12 definincJ individual labels 14, each ~rovid~d with printin~ 16. Catchpoints 18 serve to hold the labels to the rern~inder of the ~leb lO,~ut the catch~oints can ~e burst or cut to enable remov~l of label~ 14 leaving a resi~ual skeletal waste.

As show~ Fig. 2, the web 10 is madé u~ o~ a central su~stra~e web 20 which is of a non-fi~rou~ and su~stantially ine~.tensibl~ material alld on one side o~
which i~ a~plied a pressure sensitive adhesive coatincJ
22, ar.clon the other ~iee is applied a r~lease coatinc~
24. ~rl.~ we~ i~ shown in ~reatly enlar~eci ~imension in Fig. 2, to il]ustrate the slits 12 ana also to illu~rate how t~le COati nC~ materials ~2 ~nd 2~ rniyr~te into the said slits 12. The substratge ~0, aahesive coating 22 a~d release coating 24 are of a nature as described herein, and the web is wound so that the adhesive coatiny ~2 is to the inner side of e~ch coil 05 and cont~cts directly on the release coatir,g 24 of the adjacent inner coil. This arr~ngement enable~ the web 10 to be e~sily unrolled. The web may ~e wound on a suitable core 26.

In produciny the we~ 10 as illustrated in Fi~. 1, the printing 16 (single or multi coloured ~nd o~ any desire~l pattern and~or content) i!; ~pplied to the subs~ratc 20 prior to the appliation o the coa ting 24 and in addition, the perfor~tisns or ~lits 12 are ~orlne~ prior to the application o~ the ~aid coatin~ 2~.
The coatin~ 24 in rac~ n~ the e~Iect o~ assi~tincj the holdin~ o~ ~he labels 14 in ~osition in the web until ~hey are remove~ for a~plica~ion to articles. ~'he coating 24 also serves the purpose o~ preventin~
migr~tion of the adhesiv~ 22 though the slits 12 ~,1hen th~ web i~ wound on core 26. This tendency to nligrate will depend upon how tightly the roil is wound on core 26.

25 Figs. 3 and 4b illustrate diagramlo~tically how the individual labels 14 ~ay be removed from the we~ 10 and auplied to can bodies such a~ can body 28. In fi~. 3, the web 10 is shown â~ travelling round a yuide druln30 in the directisn of arrow 32, wit~- the~ pre~sure 30 sensitive adhesiv~ coating side out~rmost. E~ch can 2~
to be labelled col;le~ into con~act with th~ pres~ure sensitive side or the web 10, and a label 1~ i5 remoYed from the web 10 and applied to the can ~ody 28, as shown in Fi~. 4.llow thi~ is achieved will depend upon the design of tlle equipment, but it is envisayed ~ha the we~ 10 will '~e held ~y suitable s~rocke~ wheels or roll~rs enyayiny lioles a~ èach side of the web and tbe web ~lill b~ indeY.ed forwards to~rd~ th~ product to be labelled. The leading edc~e of the label, h~vin~ re~ard to its airection of movement ~arro~s 32), can be released from the web by a suitable knife or by virtue 05 of chan~ing the direction of movement of the web sharply. The contact pressure between the ~ressure sensi~ive surface and the p~oduct beiny l~belled can be used to efect or assist the coin~lete removal of the label frol~ the web. The removal may if necessary be assisted by severiny the remainincJ catchpoints 18 by means o~ suitable knives positioned a~propriately. lhe skeletal ~7aste of the web 10 may be wound up into a suitable coil or disposal.

The web shown in ~iy. 1 has the labels d~fined the~ein by t~e perforations or slit~ 1~, which are arranyed to leav~ a skeletal waste, ~u~ in t~le arr~n~emenr o~ Fic~.
5, tne ~lit~ 12 define lin~s of weakeninc~ ext~ndirJg across the entire width of the roll, so that the individual labels 14 con~titute the entire ~7eb ~7ithout any wast~ge. The feed and applic~tor apparatu~ or handling this forll~ of web m~y }~ave to be modified as there is no resulting skeletal waste, and if necessary, the corners of the labels rn~y be profiled as indicated by referencc numeral 34. '~he ~7eb 10 of the roll o labels shown in Fig. 5 is constructed in the sarne manner a~ the web described in rel~tion to Figs. 1 ~n~

In t~le arranger,lent shown in Fig. 6, a web 10 carries printil~ 16 which rcpeats at pitch l~ngth~ P, ~u~ the web has no perforations or line~ of weakénincJ. The wen defines contiguous labels which have to be cut from the web by suitable cuttiny equipment located in thc- region 3S of the applicatioll head 36 so t~lat individual l~bels are cut frorn the web imlllediately prior to or durinc application of the label to the drticle ~ to ~hich th~

;4 label is being a~plied. q~e individual la~els can nlal.e up the entire web as illust~ated in the arranyement of Fig. 5, or can be portions to be cut ~rol~ the ~7eb as indicated in Fig. 1, ~ut in this arrangement also no 05 carrier sheet is required, as the web lo will be constructed in the same fashion as ~he web 10 illustrated in Fig. 1. Fig 7 shows, in so~ne~lhat ~reater detail how labels in roll orm as shown in ~iy.
1 may be applied to boY. shaped products 40. ~rhe roll o~ labels is indicated by numeral ~2 and is un~ourlcl rom this roll by a tractor unit 44 haviny a suitable sprocket feed device which engaycs the holes in the margins of the web 10 ~the said holes are not sho~n in the drawinc~s) an~ is fed through a removal and application station 46. The skeletal residue o the web 10 i~ wound in~o roil fornlas sho~tn ~y nllmeral 4~.

The a~hesive side of the ~eb 10 is the upper side and all surface~ which contact this adhesive side ~re re~uired tO ~e of a nature so as not to adhere to thf~
adhesive. Such suraces may ~e defined by silicone release material.

The rernoval and application station 46 com~rises an uppc-r ~r~sure nip roller 50 ~silicone coate~) and a lower vacuum cylinder 52 around which the wfb 10 laps slightly as shown in Fig. 7, and which ~la~ ~ plurality of circum~erentially spaced ports 54 which connect with axially extending pas~ages 55, which ~re selectively connectable to a source of vacuum or, when at detachment position 56, ~7ith a blast of air under pressure. ~ valve plate 5~ at one end of the cylinaer controls the col~nection of the passaye 55 to the source or VaCUUli~ and the blast of air in-that said plate 5 has an arcuate ~ort 60 coupled to the source of vacuum ar.d a ~or~ hole at ~osition 56 connected to the air under ~lr~ssure~ In use, tne~ cylinder 52 rota~es in ~he 43~;4 direction of arcow 62 ~ ilst the plate 58 remains stationery an~ each passage 55 w~lich re~isters with port 60 is connected to the source of vac~um. Each passage 55 whic~) leave~ register with slot 60 arrives 05 first at position S6 where it receives ~ blast of air under pressure, and then the pass~ge is blanked o~f until i~ once more reaches the port 60.

Operation of th~ unit ~6 will be under~too~ from the above. The individual l~bels L are det~ched by the vacuum at the nip between roll~r 50 an~ cylinder 52, and tra~el round with the cylinder 52 until they re~ch station 56 a~ whic}~ they are proc~resively applied to the produ~ts 40 which are moviny as indicated by arrow 63, ir- ~ynchronism with ~I)e feed of the l~bels. To thi~ end the labels and pro~uct~ may be fcd on an i~dexincJ or contir~ou~ ba~is, witll int~rlirl~in~ controls en~uring that the op~ration proc~eds only wh~n the presencc o~ a la~el and a ~roduct has been cletect~d.
The arranyernent shown in Fig. 7 could be mo~ified to handle a roll of labels such as shown in Fig. 6, which are re~uired to b~ cut from the w~, and a ~uitable die cuttincJ rnean~ would be provided in the re~ion of the application st~tion.

It is estilna~ed tha~ the a~paratus sho~n in Fig.7 will be capa~le of applying label~ at the rate o ~prox.
200/min in part because the la~el roll h~ no ~acking ~trip.

Refc-rence is now r"ade to Figures 8 to 11, whic~l sho~
m~thods of manufacturing labels accor~ing to the in~ntion.
l~elerrinc~ to Fig. 8 of the drawings, a roll 110 o~
stocl; n\aterial in which la~els are to be form(:d may lZZ0764 1~

suitably l~e of a ~"idth of 450 millimetres ~nci thic~;ness 80 micron, the material may be a l~lo~Jn rilm manu~actured from a filled plastics mat~rial o~ t~e nature set out in ~ritish P~ent~lo. 1,55~,143, but in 05 any event should be a nor,-f ibrous and substan'cially non-extensible material. The web passes f rom roll 110 throucJh silicone comp~und coatiny assembly 112 at ~hici-, release coatin~ is applied to one side (the ~irst side) of the web, and then the web travels t~rou~h a heat~ r,g 10 chamber 116 which is divided into t~70 comp~rtmellts 118 ~ and 120 by means of a horizontal partition 122. The release coating is cured by passing the web back an~
forth through the chamber 118 with the first side initially ~ace ~ownwards then face up~ards. The web emer~es from the chamber 11~, after a traverse time of 20 seconds in an enviror.ert~ ~aintaine~ at 1~0C, ana the web is engaged by a pair o~ yuide rolls 1~4 arld 126.

The web next passes throu~h a pressre sen~itive adhesive coater assembly 12~ of the form s~lown ~1hich applies pressure sensitive adhesive com~osition to the other and secon~ side of the web. The web is Ied b~
mean~ of feed convèyor 130 into the upper heating chamber 1~0 which isl~aint~ineu at 110C, in order to drive o~ thc solvents o~ the a~hesive coa~inys, to ~r~
same. The emergent web ~asses over guide rolls 13~ and 134 ~134 being silicone coated so that it will not stic~ to the adhcsive side or the web which it contacts) ~nd then passes ~hrou~h die cuttir~ rolls 3S, 138 (138 beinc~ silicone coate~) which def ine the individual labels in the web, and the web is ~oun~ illtO
roll 140~

Com~ared to conventional methods of applyin~ silicone coating to webs for the production of lai~els, ~hé above equipment is e~tremely simple and can ~e o~era~e~ ~y 0'7ti 9 convertors of raw ma~erial on ~n in-house basis, the entire treatrnent havin~ a cyle time of no more than half a minute to one rninute and the overall lenyth of the a~paratus being no ~reater than ~-10 l~letres. The 05 web material 110 will usually bc pre-printed to de~ine the label printed Matter, and the silicone composition is applied over the printed side of the web. The rollers 124 and 126 may be the rotary die cut~ing rollers in order to define the individual labels in the web by cutting throuyh the ~leb to define the labels but also to leave catch points whereby the labels re-nain connected to the web stock materiâl until ~isplaced therefrom, instead of rollers 134 ana 136.

lS In the arrangement shown in Fig 9, tile silicone r~lease ~oating is an ultra violet curable r.a,eria~, and there~ore ~fter the coatin-~ is applie~ 2e ~leb is passed tSlrouyh an ul~ra violet dryer 140, ~7hich is quicker and less ~xpensive tharl hot air dryin~. ~rhe adhesive is applied and dried as before.

Tn the arrangement of Fig. 10, bot~ the silicone release coating and the adhesive ar~ ultra vio~et curable and therefore there are t~to ultra violet driers 140 and 142 respectively for the silicor,e release coating and the adhesive, throug~l which the ~teb passes in turn af ter application of the respective coatin-Js.
Fig. 11 shows an arrangelllent similar ~o ~ig. 10 i-l that ultra violet dryers are used. Only the pa~h o~ tra~el o the web is different~ The parts of trle a~r~ara~u~ in Figs 9, 10 and 11 already referred to ir, ~iy. ~ are designated with t~le sa!ne reference numerals. Irl e~ch of the arrangements shown in Fi~s ~ to 11, ti-~e ~teb travels first through the silicone coater 112 and secon~i throuyh the adhesive coatcr~ This ordc-r could be reversed if ~esired. ~lso, an arran~emcn herein a UV dryer is used for the a~hesive and a hot air dryer is use~ for the release coatil-y ean b~ adoptc-~.
another form of dryer which can ~e used at l~a~t for the adhe~ive i~ a radio frequency dryer.

~5 In t}-e ~roduction flow ~a~h in an-~ o~ the apE~r~1us ~f Fiqs 8 to 11, after the ~tage of aypli~âtion of the adhesive, all of the rollers wrlich conia~t ihe adh~sive side are ~rovided with a silicone coating irlorder to prevent stickin~ of the rollers to the adhesive, and of course it i5 ~o~ible in accor~ance With the invention directly to wind the we~ 110 after the adhe~ive and silicone materials have been applied in t~at t}
silicone side of the web will not adhere to the a~hesive in the coiling and uncoilin~ of the we~.
'l'he ~ced and simplicity of production i~ acr~icvc-a r,-i selectin-J a web ma~eri81 w~liCh i~ noll-f i~ous arld t~lerefore will not absorb exces~ive of am~urlts ol the silicone material, which ha~ens when ~a~er ~Je~bs are coated a~ in the conventinal method of ~roducin~
adhesive labels.

The web 110 may be yrovide~ with apertures in the nlargins thereof to enable the fee~iny ~ tne we~ ir.tne a~par~tu~ for removal OL the la~elæ fro~ the web fvr application to articles before or after bei;l~J coated.
The said apertures may a~so serve for the drivin~ o~' the web throuyh the~ equi~jJnent shown in FicJs ~ to 11, Wh~n ti~ ~ilicon~ coating is heat cureaJ the temperature at which the curing o~ the silicorJe co~tir~c;
takes place will ~e dictated in fact ~y thcJIlat~ri~l of the web, ~he ~eed of the web an~ the thickne~s or t~e coatin~. Clear~, alt~louyh the curin~ ti~"e carl he reduced by increasin~ the curin~ tempera~ure, the temyera~ure canno~ be so hi~h ~s ~o cause ~i~irlte(~r2tion of the web Illateri~l itself, ()764 1 It is preferred that the operation will process on a continuous basis, but it can be arranged to take place on a step by step basis with dwell times during which the silicone is cured ana the adhesive is dried.
Any suitable form of pressure sensitive adhesive can be usea .
The thickness of the web can depend upon the application, but typically labels are manufactured in a thickness of approximately 25 to 250 micronsl with the fillea plastics material web being typically 80 microns. The quantity of silicone coating which is required for such labels typically would be as little as 2 gms. per square metre, whereas with paper webs as much as 40 gms. per square metre may be re-quired.
As concerns the method of producing the labels, an ad-vantage of thé preferred method of the invention resides in that the polymerisable release coating, which may be a silicone compound, can be polymerised in a relatively short time by virtue of the fact that the substrate web matérial is non-fibrous and therefore will not absorb the reIease coat material when applied. This means that only a fraction of thé amount of release coat material normally applied will be used (as little as 5~ as compared to the conventional method) and correspondingly the curing time is significantly reduced. With a slow curing time, correspon-dingly simpler and therefore smaller machinery can be employed for the manufacture of the labels.
Tests using a silicone release coating material applied in amounts of 2 gm/sq metre have shown that 10 seconds in a chamber heated to 120C achieves satisfactory cure of the silicone release coat material.

Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of applying labels to articles comprising the steps of:
a) moving the articles in sequence past an application station, b) unrolling a web of material having adhesive on one side, c) feeding the web of material continuously to a severing station defined by the nip of first and second co-operating and continuously rotating rollers, d) severing labels in sequence from the web of material to leave a skeletal waste web, e) leading the skeletal waste away from said nip and winding it on a take up roll, f) holding the severed labels in turn to said first roller by applying a vacuum through the circumference of the first of said severing rollers, g) transporting the labels by said first of the severing rollers to the application station, and h) adhering the labels to said articles by said adhesive by pressing the labels thereto.

2. A method according to claim 1, wherein the web has the adhesive to one side and a release characteristic on the other side and rolled without a carrier web.

3. A method according to claim 1, wherein the labels are applied directly from the vacuum drum to the articles by the pressure contact in sequence between the vacuum drum and the articles.

4. A method according to claim 3, wherein the vacuum drum is also connected to a source of fluid pressure which is used to blow the labels from the drum when they reach the application station.

5. A method accordinng to claim 1, 2 or 3, wherein the web is fed at a speed permitting the application of labels to articles at a rate of the order of 200 per minute.