CA1089615A

CA1089615A - Method and apparatus for making self-adhesive covering and insulating films

Info

Publication number: CA1089615A
Application number: CA255,469A
Authority: CA
Inventors: Heinrich Beck; Heinrich Schaperklaus; Fritz Konermann; Hartmut Upmeier; Werner-Josef Zimmermann
Original assignee: Bischof and Klein SE and Co KG; Windmoeller and Hoelscher KG
Current assignee: Bischof and Klein SE and Co KG; Windmoeller and Hoelscher KG
Priority date: 1975-06-23
Filing date: 1976-06-22
Publication date: 1980-11-18
Also published as: YU150876A; IT1066972B; JPS524563A; FR2315388A1; YU40456B; HU177171B; FR2315388B1; CH627492A5; DE2527942A1; GB1553881A; BR7603872A

Abstract

ABSTRACT OF THE DISCLOSURE

In a method of making a self-adhesive composite web, a carrier layer of thermoplastic material and an adhesive layer of a solvent-free non-cross-linkable elastomer are brought into face-to-face relationship whilst in a heated condition. The component layers may be extruded separately and subsequently brought together, smoothed and then coiled, or they may be produced in contact with one another by co-extrusion through a two-layer nozzle and then smoothed and coiled, or they may be produced simultaneously by a tube blowing apparatus from which the composite tube is taken off, flattened and slit before coiling.

Description

108g6~5 Ihe l~ntion relates to a method of makin~ ~elf-adha~ive oover-ing and lnsulatin~ film~ compri~lng a carrier of thermopla~t1o ~aterial and an adhe3ive layer of non-cro~s-linkable, ~olve~t-free elastomeri~ -material, a~ well as an apparatus for oarIying out this method.
In ma~y ~pect8 0~ daily life, on buildi~g ~ites a8 well aB for ~-:
in & strial produot~ one require~ large qu~ntltia~ of ~el~-aaha~ive ~ :
~trips for ~ealin~, ~oining and insulatio~ agalnst humldit~ or electri-city. The actual strips can oon~ist o~ the most ~sried material~, . -for e~ample ~upporting fabri¢s, tha~moplastio films that may possibly be stretohsd, thr~ad layer~ or metallic BtripB-Tb ~ake ~el~-aahe~iYe fil~a and strlp~ it is know~ to apply to tbe oarrier strip unoro~-linked or no~-o~oos-linkable ~atural or synthetio rubber~ (elastomer~) out of a solution~ to evaporats the ~ -solv~nt o~ d to ooll the re~ultant strip for desp~tch a~d fbrther u~e. ~br the p~rpose of msstiol~in~, i.e. a oal~ulated molecule : -xedl¢tion, ~h- ela~omer i~ u~ed in a more adheei~e for~ a~d poa3ibly ~odified b~ the addition of other resi~. In the kllDWn m~bhod~ ~or makin~ ~dheslYe stripe, the u3e o~ solvant~ re~ults 1~ conaider~bl0 diaad~ant~g~s. Ihe layer of u~oro~s-llnked or non-oro~s~ kable ela~
mer~ applied wi~h a eolv~nt gQnerslly ~o~ t~ o~ about up to 7G~
~olvent~ wblo~ mu8t be ev~porat~d off. ~he e~aporation ~qui~e~ not only an increaee in the oo~t of maohiner~ but ie al~o a ~ir~ hazard and may l~ad to envlrcn~ntal pollu~ion. ~ furthe~ disad~anta~e of the :
m~thod of makin~ a~ha~l~e tapa~ wl~h a aol~eat re~ides ia the ~low pro-os~aing ~paed ~ade nece~a~y by ~he lon~ evaporating time f~r the :
~ol~ent. lhi3 ba0i~ally aselude~ the po~ibillty Or ~norea~ing the ou~put an~ result~ in a comparatively hi~ prloe fox the aaheolve tap~ ~aae b~
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L0~9~;15 the known method.
The invention aims to avoid the aforementioned disad- -vantages by providing a method of making self-adhesive covering and insulating films in which the self-adhesive layer does not have to be applied out of a solvent.
According to -the invention, this is achieved in that the carrier web of thermoplastic ma-terial and the adhesive layer of non-cross-linkable elastomeric material are co-extruded from a two-layer nozzle, cooled and subsequently coiled. By combining the two layers in the thermoplastic range, one obtains excellent ~
adhesion between the layers, whilst the surface adhesion can be ~ ;
influenced in the desired manner to meet requirements by modifying the elastomeric material.
By means of the method according to the invention, self-adhesive covering and insulating films can be produced in a simple and economical manner and thus the field of application of the films can be extended. For example, the films according to the `
invention can be used for insulating building works, for which purpose different materials have for the most part been used prev-iously.
To improve the surface adhesion, it is desirable to apply out of a solution a thin layer of a modified elastomer onto the relatively thick adhesive layer of non-cross-linkable elasto-meric material applied by the extrusion process. With this very .
thin layer applied out of a ~-." ~ .: ' ~
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solution, no problems ari~a during evaporation or dryinæ. ~his appli-cation of a thin ~dhe~ive layer out of a ~olution offera advantages when thick adheaive layers with optimum surface adhe~ion are required, for example when it is necessary to cement axti¢le~ having a vsry uneven ~urface or which are partially soiled.
Another po~sibilit~ of inoreasing the adhesion i9 obtained in a¢cordan¢e with a development of the in~ention in that the aurfaoe adhe~ion is lnorea~ed in the extruder for the non-cros~-linkable elastomerio ms~ by ohane~ng the proces~ing temperature 3nd/or by a calc~lated mastici~iu~ proce~s (molecule reduction). Dhe te~perature ¢an be ea~ily pre~oribed b~ a predetermined progr~mme for the extr~der that prooe~ses the ela~tomeriG ma~s.
In another embodim~nt of the inr~ntion, the re~ultin~ marelnal strip~ of wa~te thermopla~tlo carrier material havin~ a tightly adher-inB slaatomeric lay~r o~ adhe~ive are regranulated, mixed wi~h the fresh the~mopladtic mat~rial and formed as the carrier web by the extruder for the thexm~pla~tio material. Daring the produstion of ~he ~elf-adhesi~e films it i~ u~ual for a mareinal strip to eoour a~
~aste and this can be ut~ ed to improve the desired aahe~ive ~trip propertie~. ~y mixing thi~ mareinal ~trip into the fre~h materiQ- for tha tharmopl~o~ie oarrier film, ~h3 latter will eæhibit a ~mall pero~n~
tage of ela~tomeri¢ non-oross-liDkable compo~ant~ wh~oh~ ~fter a ~hert etor~ng period, migrate to bhe aurfaos of the oarrier ~trip and thereby lmprove the adhe~abili~y of ~uoh a film. Ihi~ e~fe¢t i~ of partioul~r lmportano3 when ~rtiole~ are to b~ helioally taped, ~or example ~or in~ulation ag~ln~t bumidi~yl wher~ good adhe~ion i~ bo occur to the articla being taped as ~ell a~ to the e~po~ed ~urfaoe o~ ~he oarrier web. ~part frcm improving the proce~ability of ~uoh ~ coverin~ a~d ~-~nsulating tape, t~ia me~hod permit~ ~he o~herwi~e annoglng marginal ~ waste to be ~sed up ~n a simple manner by reo~ollng.

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An apparatus for carrying ou-t the me-thod according to the present invention is characterised according to the invention by a two-layer wide-slit nozzle for forming the carrier layer from thermoplastic material and the self-adhesive layer from non-cross-linkable elastomeric material, a downstream pair of rollers of a smoothing device, a cooling section formed by cooling rollers for guiding the self-adhesive web of film, as well as a downstream coiling station.
The method according to the invention can also be carried out by co-extrusion of the thermoplastic carrier web and the non-cross-linkable elastomeric mass from a two-layer annular nozzle in a film blowing process, the carrier web being either on the inside of the tubular film and the non-cross-linkable elastomeric layer on the outside of the film or these two layers being reversed in rela-tion to the positiion of the tubular film bubble.
Other advantageous features of the invention are des- -cribed in more detail in the subsidiary claims.
Examples of the invention will now be described with reference to the drawing, wherein~
20 ~ Fig. 1 is a diagrammatic representation of an apparatus for coating a carrier web of thermoplastic material with an adhesive layer by an `^-~

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extru~ion prooe~s;
~ig. 2 i~ a dia~rammatio represffntation of a two-layer wide-slit nozzle or plate apparatu~ for the co-extrusion of the thermopla~tio carrier web and the no~-oro~-linkable ela~tomeri¢ layer;
Fig. 3 i8 a diagrammatio repres~ntation of a two-layer film blowln~ plant with the th~rmoplastic caxrier web on the in~ide o~ the tlbular film and tha no~-oross-linkable elastomerio adhe~i~e layer o~ the outside of the tubular film, and ~1~. 4 ia a diagramnatio representatio~ of an installatio~
oorre~p~nd~n~ t~ Fig. 3 ~ith the thermopla~tio carrier lay~x on the out~ide of the tubular film and the non-cro3s-linkable ela~omeric :
adhe~ive layer on the in~ide of the tubular film. ;~
In the ext~u~ion coatine plant aooording to ~1~. 1, the n~n-or~s- ;~
linkable elastomerio maberial io oon~ayed by m~ans of ~he sorew extruder 1 ~hown in ~impli~ied fo~m, heat~d and pla~tioi~ed asd ~ed -through the conneotDr 2 intD the wide-~lit no~zle 3 kav~ng the distri~
blti~ pa~Eag9 3~. ~he carrier tape of thermoplastio material i3 fed : :
from ~he ooil 6 over the ooolin~ roller 4 of the ~moothin~ devioe 4, 5, pa~t the heat E~Iroe 7 in a manner known per ~e into the ~oller nip of the smoo~hing d~vice 4, 5 where the web of non-cro~ ksble el~3to-merio materisl 1B applied in ~he form of a flat film. ~he pre~3ure roller 5 of the 8othiJ45 devioe ~or the ela~tomerio aahs~ de of ~he wsb i6 pref0rably pro~id~d wibh a regellent surf~e suoh a~ a ~ilioon rubber ooating whioh pre~se~ ~he tw~ layer~ to6ebher, oalibrates bh3m (bring~ ~hem to a unlfoxm thiskne~) and ~imultaneo~ly 00018 them. ~he resulting ooated we~ of ~he carrier material 8 and the adhesi~e laDer 9 ie led throu~h a cooling ~eotion havlng ~he ~upporting ~oller~ 10 and fed over a direotion ohaaglng roller 11 to the ooil~
apparatus 12. If exoessi~e adhe~io~ hamper~ u~ooiling dur~g ~uxther prooec~ing or even m~e~ it in~D00ible th~, if de~ired, a suitabls :

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~8~311;~5 eepæating web 13 of a coated material or a coated film tape can be included in the ooil 12.
An alternative to Fig. 1 in the form of a oo-extruded n at web iB shoMn in ~ig. 2. ~hs diagrammatically illus~rated ~oraw extruder 1 oon~ey~, heats and plaaticlzes the non-oross-linkable elasto~erio mater~al and feed~ it through the conn~otsx 2 into the ~wo-layer uid~-slit nozzle 16 and then i~to the distributin~ pas~age 161. The dia~ammatically indicated ~orew ext~uder 14 feeds the thermoplastic material ln a mslten Qondition thrnugh the connec~or 15 into the :
distributing paHsa4e 16~ of the hou~ing o~ ths wida-slit nozzle 16.
~he expelled two-layer tapa oonsisting of ~he ca~rier material 8 ~ :
and the adhesira layer 9 is, a~ in the case of Fig. 1, oalibrated by the ~moobhing device 4, 5 having the cooline rollers 4 and the roller 5 p~ovided with the r~pellent surface, taken off and cooled along a .~ :
oooling section having the supporting rnllers 10 and fed over the direction-changin~ roller 11 to the ¢oil 12, it al80 being po~sible : .
in thi8 oa~e to include, if desired, a separating web 13 in the coil if ~he adhesive foroe i8 too ~reat to permit trouble-free un~olling.
If thi~ separatin~ web 1~ i8 ba~ioally required~ the xepell~nt slrfaos of the roller 5 of the ~moothing device 4, 5 can be dlspen~ed with by pa~s~n~ t~e ~eparating web 13 over the roller 5 of the smeothin~ de~ioe, althou4h ~his avolds the nead for equlpping the roller 5 with a repellent sur~a¢e, the cooling bahaviour of ~he co-e~truded ~eb 8, 9 i~ inferior. :
me layout of ~ig. 3 ~mplog~ the known two-layer film blowing prooes~. ~he diaeramma~ieall~ indicated ~orew extruder 1 feed~9~he : -plasticized ela~tomerio material of ~he adhe~ive lag~r throu6h the oo~nector 2 into the housing of the two-layer film blowhead 17 havin~ :
the annnl&r paasage 17~. ~he thermopla~tie material of the oarrier web is fed by mean~ of the diaeramratieal].y indioated ~ore~ extruder 14 and :. . - . . . . : , .

~)8961~

led through the connector 15 into the di~tributi~g pa~age 17 of tha fi~m blowhead 17. In addition to the exterior ¢ooling 2~, the expelled two-layer tubular film i3 praferably cooled from the inside by means of the known interior coolin~ apparatu~ 19 in which the internal cooling air 18 i~ pa~ed through the concentric annular pa~sage into the interior cooling apparatus 19, leave~ at the ~lot~ ~0 and i~ preferablg led at the upper re~ion of the tubular bubble 20 by mean~ of the ~uotion tube 21 &nd a~pelled as heated air 22 by mQans :
of a suotion blower (not ~ho~n). ~he tubular bubble of film havlng ~he aahe~ive layar di~posed on the outside oa~ be brou~ht to the de~ired nomi~al dimension~ by mean3 of ~he calibratine appara~us 32, :~
the eupportin~ elemeats havin~ a repellent sur~ace BUCh a~ of ~ilicon rubber, a~ do all the subsequent roller~ 10, 24~, 25 and 27 comin~ -into contaot with the a~ha3ive layer.
~fter oooling, the tubular film 8, 9 i~ taken off from the - :
n attening elemant~ 24 whioh preferably comprise rotar~ flattenin~ -roller~ 24~ and by mean~ of the palr of take-off roller~ 25, fed over the guide roller3 10 to the ooiler and, a~ter bhe edg~ of the flat- . ; :
t~ned tubular ~ilm 8~, 9~ hav~ been ~lit open by mean~ of the diagrammatioally indioat3d ~litting knives 26, fed o~er ~he palr of roll~r3 27 to tho bwo o~iling ~tations 12~, 12i7, ~he rolleIa 27 : -preferably be~ng in the for~ o~ driven ~aed rvller~. In thi~ arrange-ment a ~eparating web 1~ 13l~ can alBO ~U~ into the 00118 127, 12 lf required~
~ie. 4 desoribe3 an alternati~e tD bhe aforementioned two-la~er film blowine plant i~ whioh1 bowover, the carrier web of the~moplaatio mat~rial 8 i8 dl~posed o~ ths out~ide of the ~ubular ~ilm ~nd ~he adhe~ive layer 9 o~ ~Dn-oro~-liDkable ela3tomeric matexial i~ dispo~ed on the in~ide of the tubnl2r film. qhe tubular ~ilm 8, 9 fo~ed by ~he t~o-lagex film blowheaa 17 i8 cooled by the ~nter~al cooling apparatus .., . - .: ' . . , ' , . , ~L138'3t~1S

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19 and the outer oooling ring 23. In oo~tra~t with the ~ig. 3 apparatus, the internal cooling air 20 iB led pa~t the ba~fle plate 29 whlch iB connected .to the internal oooling apparatus 19 by the holding element~ 2a and the diameter of which determ~n0~ the diameter of the tubular film according to the baffle cushion principle. The heated internal cooling air 22 flows to atmo~phere after passing the b~ffle plate 29.
A~ter adequate cooling of the bubble of tubular film, lt is ~lit opon by two oppo~ed slitting knive3 30, spread out over au~iliary rollers 311, 31tl and taken of~ b~ the two pairs of t~k~-off rOllerB
25~ 25ll. Eaoh takq-off roller lying on ~he adhesive Bide must be : ~-provided wlth ~ r~pellent ~urface ~silicon rubbar or the like). A~
in the previou~ e~ample, t~ $ini~hed ~elf-adhe~ive web of filn i8 fed over fhrther guide rollers 1019 loll to the coiling stat~on~ 12 12~1, it again being po~sible to include separating web~ 131, 13l~
This apparatus ha~ the advan~age that ~ewer gNide rollers come into ~.
contaot with the adhasiva ~ide of the finished web of ~ilm but on the other hand bhe baffle plate 29 must be replaced wh~n the ~ize i~ :
ch~ngsd (ad~ustm~nt of width).

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method of making self-adhesive covering and insu-lating films comprising a carrier of thermoplastic material and an adhesive layer of non-cross-linkable solvent-free elastomeric material, in which the carrier web of thermoplastic material and the adhesive layer of non-cross-linkable elastomeric material are co-extruded from a two-layer nozzle, cooled and coiled, and a thin layer of a modified elastomer is applied out of solution onto the relatively thick adhesive layer of non-cross-linkable elastomeric material applied by the extrusion process to improve surface adhesion.

2. A method according to claim 1 in which the surface adhesion is increased in the extruder for the non-cross-linkable elastomeric mass by changing the processing temperature and/or by a calculated masticizing process (molecule reduction).

3. A method according to claim 1 in which marginal strips of thermoplastic carrier material having a tightly adhering elastomeric layer of adhesive are removed as waste from the films so formed and are regranulated, mixed with the fresh thermoplastic material and formed as the carrier web by the extruder for the thermoplastic material.