COUVRE-MURS

WALLCOVERINGS

Abrégé anglais

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ABSTRACT
TITLE: WALLCOVERINGS
Pieces (15) of prepasted foamed wallcovering are made in a
two-location process. At the first location a web of paper substrata
(10a) with a formable coat (10b) is given a print (10c). At the
second location the printed web is given a pre-paste coat (10d) with
an adhesive capable of providing remoistanable features after tolera-
ting heat conditions to be encountered during a subsequent foaming
step, and the pasted, printed web is then given at the same location
any subsequent treatment required (such as embossing) including heat-
ing to generate the foam.

Revendications

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THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for making printed foamed wallcoverings in
piece-wound form in which the completed wallcovering has
a rear surface having a coating of a dry paste which can
be water-wetted to provide a wet adhesive surface prior
to hanging, and a front face having a chemically foamable
material which is foamed by a heating step, the process
comprising:
(a) at one location, unreeling a base web carrying said
foamable material, printing said base web and
re-reeling the base web,
(b) at a further location, applying to the said base web
a paste coating capable of tolerating heat in a
subsequent heating-to-foam step,
(c) heating the resulting coated base web to perform the
foaming, and
(d) piece winding the resulting treated base web.
2. A process as claimed in Claim 1 further charaterized by:
(a) providing the reeled base web with a foamable PVC
coating, and
(b) gravure or flexo printing the web.
3. A process as claimed in Claim 1 further charecterized by:
(a) providing a paper substrate for the reeled base web,
(b) providing two screen printed foamable coats of
differing colours applied at the second location.

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4. A process as claimed in Claim 3 further including:
(a) providing the paper substrate with a ground coat.
5. A process as claimed in Claim 3 or 4 further including:
(a) embossing the printed and pasted web prior to the
said heating-to-foam step.
6. A process as claimed in Claim 1, 2 or 3 in which:
(a) foaming the web in a temperature range of between
180° C to 220° C for 15 to 40 seconds.

Description

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WALLCDVERING5
Thia invsntlon rslatas to wallcoverings.
Tha invsntion i~ concsrnsd with th~ subjact of prspastad wall-
cnv~ring~ and i~ aimsd at providing apparatu~ and a proc3~s for ma~lng
prspaRtsd chsmically foamed wallcovsring~.
A proca~ already ussd ~or making prspastad foamed wallcovsring
involvs~ conducting sub procassas at thres location~, namsly:
Location No. 1 Un-rssl foamabl~ ~eb; print; rs-rsel and
tak6 to Locatian No. 2.
Location No. 2 Un-raol printed foamabla wsb; hsat to foam;
rs-rasl.
Location No. 3 Un-rssl pri~tsd ~oamabls web; prapasts;
pisca wind.
This alrsady u~ed procsss has potantial problsm points. For
example, any damage occurring aftsr printing (such a~ may ari~e in
hand}ing, transport and storags o~ rssls) i3 damag~ to a product to
which qignificant value, namely the printing, ha~ besn addsd. Any
damage occurring aftsr foaming involves 1089 of ~vsn grsater valus.
Fùrth~r a foamad web i9 soft and bulky and i~ quscsptibla to damags
and i8 not suitabla tor convsntional ~torags as a rsel fr~-Rtanding
on a floor as ths ~oam in proximity to ths floor bscomss crushad.
Thus it i~ ths practica to support rael~ of ~oamsd wsb ~n csntrs
~upports mountsd on block~ which i~ mora troublssoms than fras-~tanding
4torags.
Ths invsntion disclossd in our application No. 81~7022 (G8 2110
956A) provide~ an improvsd proca~s which, whilst not removing all ths
problem point~, at lea~t r~ducss them. Th~ pressnt invsntion di~closa~
a furthsr lmprov~d proca~s in which damag~ hazard3 ~uch as may ariss in
.~

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handling, transport and storaga of rselsd products are raducad. Tha
new procass also aims gsnarally to follow ths procadura o~ printing prior
to prapasting and henca problsm3 that can arise dua to adhasiva inadvar-
tantly raaching tha print surfaca, disturbanca to tha printing surfaca
dua to an intermadiate procsss impairing print~ and inability to sustain
registsr due to prasancs o~ prepasta on the rsvarsa sida o~ tha web, ara
minimisad or avoidad.
Tha procss~ according to tha presant invsntion is a procass which
raq~iras at tha most, two locations with one rewind batwaan locations
as follows:
Location No. 1 Unrael basa web, print, and reel.
Location No. 2 Apply prapasta with an adhasiva capabls of
providing remoistenabla featuras aftar tolara-
ting heat conditions to bs sncountared during
a subsaquent foaming step (typically 180
22ûC for 15 to 40 seconds), complata ramain-
ing treatmant of printad and prepastsd web,
i~ raquirad~ foam, and pieca wind.
(For ra~3rsnca purposas tha aarly art procassas of prepasting
ars sean in G8 s88 554, 605 438, 606 648, 626 290, a2s 752, 869 422.
These pr~cssses hava be~n gsnarally rsplacad with a two-ccat systsm
di3closed in USP 3 122 445 which, in turn, is likely to be raplaced
by prepasting with 2dhasivss derivad from invarss smulsions as
disclosad in EP 0 008 213 and G3 2 054 ~28A).
Two examplas of tha invantion will now ba descriobad with .sfa_-
ence to tha accompanying drawing3 which ara flow lina diagrams of two
procasses according to the invention raspectivsly numbsrsd F19. 1 and

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Fig. 2.
In Fig. 1 a rsel 10 of ba~s web ronsisting of paper ~ub~trata lOa
having a foamabls PVC coating lOb 3upplies a gravurs (or flaxo) printing
~nit~ 11 whars a print lOc i9 applied and ths web ~torsd on a rsal 12.
This rsprasant~ location No. 1.
Ths rssl 12 i9 next movsd to luration No. 2 whsra it i~ givan, at
a gravura ~1BXO or scrssn machina 13, an applied prspa3tH c~at lDd and
thsn pa~3d through a blowing oven 14 whsrs the PVC coating lOb becomas
~oamad and formR coat lOe FrDm the ovan, ths ~inishsd wab i~ wound as
pi~C9~3 15.
In Fig. 2 a reel 20 o~ basa wab consisting of a paper substrats
20a with, pra~erably, a ground coat 20b ~upplias a gravurs (or fl0xo)
printing unit 21 whara a print 20c i-~ appliad and tha wsb ~torad on a
reel Z. This repressntq location No. 1.
Ths rsel 22 i9 next moved to lDcation No. 2 whsra it is givan, at
a gravure flsxo or ~craen machins 23, an appliad prspasta coat 20d. Ths
ramaining treatmant o~ embos~ing(i~ requirsd) the printed and prapasted
web takss placs at an emboasing station 26 ~ollowsd by ~cresn prin'ing
two foamable plastic-~ coats 208 and 2Uf o~ differing colour at atations
27a and 27~. The web then pas~ed a blowing ovan 24 and i5 wound as
piacse 25 with a foam coat 20q abovs print 20c on a coat 20b on a sub-
strats 2ûc with a prspasta 20d.
Ths adhs~i~s (lOd or 20d) i9 ~ormulatad tD b~ tolarant to tha
tsmpsraturs sncountsrsd In the ~aaming ovsns and may typically bs on~
of the "Colla~ixi' ranga of adhssives ~arkatad by Alliad Colloids Ltd.
"Collafix" is a trade mark.
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