Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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18291
ME~HO~ OF A~D ~PPARATUS FOR T~E PRODUC~ION OF
E~OSS~D LA~INA~E ~OARD
SPECIFI~ATION
My presen~ invention relates to a met~od of ma~in~
laminate board formed from a laminate ~tack ~mpregnated with
or containing a hardenable synthe~ic res~n and, more
particularly, to a m~thod of ma~ng s~ch lam~na~e board in a
single-level platen press, especlally ~or çm~ossed or
decora~ive laminate board. The invention also rel~te~ to an
apparatu~ ~or produ~ing such ~oard and, in particular, ~o a
single-level platen press ~or ~he purpose.
e- ~
I~ i8 known to pr~vide deco~ l~mlnate board, i.e. lamlnate
board which i~ pxovided on one of lts ~ur~aaes with a
partic~lar tex~ure, pa~tern or d~coration, referred to here as
embossing, by pressing a laminate containing a hardenable
synthetiq resin either as an impregnating agent ~or the
ma~erial forming the laminate or as a material ~pon the
material which con~titutes the laminate under he~t ~nd
pres~ure inJ ~or example, a pla~en press. The lamina~e is
pressed in part agains~ an embossing s~rface WhiCh lmpart~ the
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18291
pattern to a ~a~e o~ the laminate an~ ~he press can be held
closed ~or a period o ~ime su~ficien~ to ~llow hardening of
the resin and the transformation of the laminate into the
em~ossed board.
It is known in the production of embossed laminate board
to provide a stack ~onsisting of ~wo lam$n~tes separated by an
intervening layer, referred to herein as a separat~ng layer,
and to press this stack in a multilevel platen pr~s~.
Press-charging and dis¢harging units are provided ~or t~e
multilevel pl~ten press which are ~imilar in con~truction and
oper~tion to the press-charging and pre~s-disaharging units
u~ed in t~e produ~tion o~ pre~ed board, fiber boa~d, particle
board and the li~e in mul~ile~el presse5.
Decor laminate board, as a rule, i~ ~ormed fro~ a
mult~layer as6em~1y, i.e. ~ a lam~nate compos~d o~ a
multiplicity of làyers wnich must ~e assembled to ~orm ~he
stack. The intermediate layer~ ~a~ be oomposed o~ 80-called
~ra~t paper and the layers which are pro~ided with ths deco~
. ~ruct~re, i.e. which are embos~ed or patterned, referred to
generally as so-called overlays, can be compo~ed of 6yn~hetic
resin foil.
The kra$t paper layer~ may b~ ~ynthetic re~in impregnated
papers ~hich are s~acked to form the lam~na~e and covered by
an overlay.
The lamînate 1~ subjected ~o the pressuxe and heat o~ the
press to ~ransform the lamina~e into the board by hardening o~
the s~nthe~ic re~in sy6~em.
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In practice it is de~ira~le to llmi~ the num~er of
patt~rns w~i~h are to be applied ~ince each chan~ of pattern
requ~res a change of the pre~ pla~en~ whioh are used and ~hus
rPplaceable pattern plates have been developed for use in the
platen press. These p~ern plates may be comparativel~ thin,
i.e. have a xelatively small thickness ~y compaxison with the
thi~kness o~ the platen.
~ he earlier teahniques, therefore, reguired presses
de~ined ~or the production of single patterns and whic~
~emained in operation ~or lon~ period~ of time while more
recent techniques effe~t more frequent changes of pat~ern by
changes of the pat~erning plate~ for partiçular lot~ o~ ~he
laminate boa~d. As a conseg~enae, there i~ increaslng
ten~ency to use single-level presses by contra~t to multilevel
pre~ses since the pattern chanseover can be ~o~e rapid.
Both sin~le-level presses and multilevel pres~es oan be
re~erred ~o as cycling presse~ and it should be reaognized
that it is also possible ~o ~abrlcate decor laminate board in
¢ontlnuous presce~, i.e. be~ween two steel belts in a steel
~o belt press. In this ca6e, the press belt~ or at ~east one of
the prQss belts must ~ pro~ided wlth the ~tructure or pattern-
ing for the em~ossing of the lam~nate. Such pre~s bel~s do
not always of~er a satisfa~tory l~fe when used for the
production o~ decorati~e laminate~ of the ~ype described.
~5 ~eplace~ent of st~el press belts i~ al~o ~xtraordinarily ~ime
consuming so that, as a pr~otical ma~ter, suc~ presses ~annot
be utilized ~or ~h~ produc~ion of decorative laminate boards
in 6mall lo~. Th~ same ~pplles ~or multilevel pla~en
presses .
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18291
It should also b~ noted that different teahnologie~ are
invol~ed e~en in the produ~tio~ of decorati~e laminate board3
in ~o-called cycling pres~es, l.e~ multilevel pla~en pre~ses
as opposed to ~ngle-le~el platen pres~es. Proces~e~ whlch
use ein~ level platen pre~se~ can be described as short
cycle processes. A similar technology i~ involve~ a in ~he
case o~ lamination of pres~ed board ~r the li~e. Single-leve
platen pre~ses re~ulre special chargin~ and discharging
~y~tems which make use of cl~ping arrangement~ a~ w~ll b~
apparen~ fxom German Patent Documents ~E 2209901 and D~
1911764. These systems cannot, however, operate with two
laminates ~ed to a ~gle l~vel pres~ s~multaneously or for
the rQmoval o~ ~Wo pressed board3 in a ~tack with a separ~tor
between them. The problems encoun~ered Wit~ ~ese earlier
system~ ln e~orts to us~ them under ~uch ~ondition~,
espeaial~y in a ~hort cyale op~ration, i8 that upon ~h~ rapid
opening o~ the press, air enter~ the space between the pla~ens
~nd causes uncontrolled movemenk of the individual bo~rd~,
there~y m~ing it di~icult if not impossibl~, t~ remove ~he
board~ wi~h these aonventional sys~ems~
Thi~ particular problem may not characterlze multile~e~
presses and the charging and dischar~lng ~ystemC which are
normally used th~rewi~h.
It i~, there~o~e, ~he principal objec~ o~ the inv~ntion to
provide an improved ~ethod o~ producing decora~ive laminate
board and, aonco~itten~ly, an improved method of operating a
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1829~
single-level plate~ pres~ for that purpose, which prevents
un~on~rolled movement of ~e l~minat~ board and, there~ore,
eliminates problem~ hitherto encountexed in the production o~
lamina~e board with a single-level platen press.
Another ob~ect of the in~ention i~ to provide an apparatus
incl~ding a ~ingle-leYel ~laten press and a pre~s-di~charqing
unit which c~n allow rapid cycl~ng produation of decorati~e
lam~nate board.
Sti~l another ~b~ec~ o~ ths invention is to provide an
improved me~hod o~ and apparatU5 ~or ~he production of
decorati~e laminate board in a single l~el platen presR,
whereby disadva~tages o~ earlier ~ystems are a~oided.
These o~ect~ and others WniCh wlll bçco~e app~rent
h~einafter are attained, in accordance wi~h the invention in
a sys~em ~n whi~h two laminates capabl2 o~ pro~iding the
decorative laminate boards, ~ith a separator between them are
inserted as a stack into a single-level platen press which can
have repla~eable embossing plates or shee~s along the ~de~ of
~0 ~h~ plat~s con~ronting the faces o~ the two laminates to be
embossed~ The ~tac~ is lnsert2d w~th the aid o~ a aharging
devi¢e with the press ~ully opened and the maxlmum spacln~
between ~he press sur$a~es~ When th~ ~tack is laid in~o the
press, the latter is closed and held closed ~or ~hQ
p~e~etermining ~ardening time of the ~ynthetic resin under the
hea~ ~nd pressure applied ~y t~e press and the ~wo lam~na~e
~oards ~hi~h result are then drawn by a di~charging unit.
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18291
A~cording to the invention, th~ ~ta~ is ~o inserted into
the pre~s thA~ a~ lea~t along the longitudinal edges of the
stack regio~s re~ain exposed or free upon alo~ing o~ the
press. ~ese regions o~ the stack before pre s open~ng or
upon pre~s opening are engaged by the pickup elements o~ the
discha~ge unit so that the entire ~tack can be removed and the
plates thereof trimmed.
~ecause the stac~ can be engaged by the ~iakup deviaes of
the dischar~e unit before the pres~ is f~lly opened or during
lo the clo~ed condition of the pxe~s, beaause of the s~ack
rem~ning exposed e~en whe~ the pre&~ i~ closed, for ~u~
en~a~ement, ~here is no possi~ ty tha~ t~e boards w$11 mo~e
relative ~o one another before they a~e engaged b~ t~e pickup
e~ement~. These ~egions ~ the ~aak can thu~ be engaged
durin~ the pre~ing operation ant pr~ox to opening of the
prQSS, thereby precludi~g uncontrolled movement~ of the boards
and enabling the cyclin~ time ~or production o~ the boards to
be lncreased.
The processes o~ the invention can be carried out by
simply pe~mitting lon~itudinal edge z~nes of the staak to pro~
~e~t beyond the platens and emboss~ng plate~ for engagement by
alampin~ elem~n~s or by ~orming the platen3 and the emb~ssing
plates with c~tout~, poc~ets or 4hamber~ into which the
clampin~ elements can eng~ge e~en when the press ~ closed.
~or~ par~iculaxly, the me~hod o~ inven~ion can compris~
the steps of:
(a) ~orming a ~tack o~ a sandwi~h stru~ture of two
laminates aont~ining a hardenabl~ synthetic re~ln, and a
~eparating laye~ bet~een the laminate~;
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~82~1
(b~ insert~n~ the ~ta~k bet~een two pres3 platen~ O~ an
open ~ingle-level platen pres havlng e~Po~ing sur~ares
juxtaposed with opposite faces o~ t~e s~ck and positi4ning
tl~e ~t~ck in t~e press 50 ~hat at least ~lon~ one
longitudin~l ed~e of ~he 6tacX at lea~t ~paced apart portions
o~ the ~ta~:k remain free upon cl~sure of the pres~;
(a~ c:losing the press, ther~by compres~ing th~ stack
between the sura~es, maintainin~ thB pres~ closed f~r a
~eriod of time ~ufficient to effec~ embossi~g ~ the op~osite
fa~e~ and hardening of the laminates into boards, and
thereupon opening the press;
(d) su~sequent ~ the c~osing of the pres~ and ~t least
upon open~ng o~ ~he press, ~ripping the portions of the
~taak w~th engag~ng members of a pr~s3-discharging unit and,
upon opening o~ the press, withdrawing the boards with the
separating layer therebe~ween from the press; and
(e) thereafte~ tri~ing at least the portionE; from th~
boards.
~he apparatus for carrying out the method can comprise:
a single-le~el platen press having two press pla~en~
~o~med with embossing ~ur~aces juxtaposable with t~ppo~ite
~aces of a stack of a sandw~ ch structure o2 two laminates
containing a hardenable ~ynthe~i~ resin and a separatlng layer
}: etween ~he laminates;
2 5 me~ns for ins~rtinq t~e stacJc be~w~en the embo~sing
6urface~ upon opening of the single-l~vel platen pre6s 60 that
th~ e~bossin~ surfase~ are ~uxtaposed with tha opposi~e
~aces o~ the s~ack and the staçk i~ posi~ioned in the press
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~o that at leas~ along ~ne longituain~l e~ge oX th~3 ~ta~k at
lea~t ~paced apaxt portion~ o~ the ~taclc remain free upon
closure of the pres6; and
~ press-dl6char~ing uni~ provlded wit~ engaging members
~or gripping the ~ortions of the s~ack subsequent ~o th~
clo~ing of the press and at least upon openin~ of the press
and, upon openlng of the pres~, with~rawing boards ~ormed by
¢ompre~sion of side ~ta~k between the ~urfaces and hardening
of the lami~ates, with the separating layer ther~ betwe~n
from the press.
Prefexably, the press platens a~e formed with cham~ering
on their longitudinal ~ides into whi~h clamping elemen~g pas~
with the press to seize the ~tack before the p~e~s is opened.
Brie~ Desc~ ion Q~_the Drawina
The above and ot~er ob~ec~s, feature6 ~d adv~n~age~ o~ my
inven~ion will become more readily ~pparent from the following
description, reference being made to the accompanying h~ghly
diagxammatic drawing in which:
~ XG, 1 is a pla~ view showin~ two clo~ed pr~s pla~en~ o~
~0 ~ ~ingle level platen press is carryirlg out the method of th~
in~ention, to~ether with the pre~ scharging un~t;
FIG~ 2 i~ a view o~ a por~ion of the press taken generally
along t~e line XI-II o~ FI~. 1;
FIG. 3 is a view simil~r to FX~ 1 illustrating another
~5 embodiment of the inventionî and
FIG. 4 is a ~ross ~c~ional view alonq thQ line IV-IV
drawn to a l~rger ~cale,
;~049397
18~1
The platen ~res~ ~hown in the drawing compr~se~ a lower
pres~ platen 1 and ~n upper pr~s~ platen 2 o~ a heated single
pxess pl~ten, the hydra~lic mean~ for open~ng and closlng the
platens ha~ing not been illustra~ed but being conven~ional in
the art. ~IGS. 2 and 3 show the heating p~ssage~ 3 through
which ~:~perhe~ted steam, for example, can be fed.
As can bo seen from FIGS. 2 and 4, moreover, assembled
lami~tes 4, i.e. multilayer laminates o~ the type de~cribed,
~orming a sandwich str~ture ~ith a sep~rator 5, ~an
con~titute a staok which ~ placed between the platen~ 1 and 2
and ~an be inserted into ~he press by a chargin~ device ~hich
c~n be similar to the disaharging deYice described in gr~ater
de~ail below. The press platens l and 2 are lined with
embossing shee~s 5 shown to have an und~latin~ or corrugated
pattern applying the decor pattern ~o ~he laminate board which
is produced. The presses have been shown in ~IGS. 2 and 4 in
t~e closed ~tA~e in whi~h the two lamlna~es 4 are pre~sed to
f~m the de~or lamin~te board and receive the ~mbossing
str~qture imparted by the embos~ing pla~es 5.
As ~ comparison of FIGS. ~ and 2 or the respective F~GS. 3
and 4 will show, the re3pecti~e ~tacks are ~o inser~ed into
the single le~el pla~en pre~s tha~ longitudinal zone~ 7 remain
fully e~po~ed along their entire lengt~ ~FI~S, 1 and 2) or
are expo~ed w~thin ¢hambers 9 which can extend all along the
pla~ens (~IGS. 3 and 4) or only a~ ~paced ~part locat~ons
thPrealong. These zones 7 thus remain free or e~posed ~ven
when the pres~ is closed so that they c:an be en~aged by ~he
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18291
clamplng element~ 8 of ~he dischargin~ unit wh~ch ~a~ been
represented qenerally at 10 in the everal ~gure~. Th~
di~chaxging unit can be moved in the longit~dinal direction to
carry the ~tack out of the pre~s once it i5 f~lly opened ~nd,
of course, with appropriate travel can be used as char~ing
unit to bring a new stack in~o the pres~. A~ FIGS. ~ and 4
il~ustra~e, ~he clamp~ 8 can eng~ge the ~tac~ befor~ opening
o~ the ~ingle level press 60 that uncontrolled movement of the
lamlnate board ~ormed from the stack~ 4 a~ a result of air
entering the pr~ss during the openi~g opera~ion, cannot occur.
Once the boards are withdrawn fr~m the press, they can be
eparated from the layer 5 which can be compo~ed of sta~nless
s~eel or other mate~ial (e.g. a synthetic re~in coating or
foil) to whic~ the lamin~tes do not adhere, and the unpressed
portion~ of the board, ¢o~responding to the
~S regions 7, may b~ trimmed from the board by th~ conventi~nal
trimming proces~ utilizin~ co~ventional trim~ing ~aw~.
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