CA2049397A1

CA2049397A1 - Method of and apparatus for the production of embossed laminate board

Info

Publication number: CA2049397A1
Application number: CA002049397A
Authority: CA
Inventors: Wolfgang Gotz
Original assignee: Individual
Current assignee: G Siempelkamp GmbH and Co KG
Priority date: 1990-08-17
Filing date: 1991-08-16
Publication date: 1992-02-18
Also published as: DE4026046A1; JPH04226721A; JPH0659660B2; IT1251172B; FI913889A0; ITMI912248A0; FI913889A; ITMI912248A1

Abstract

ABSTRACT OF THE DISCLOSURE

Laminates are pressed into laminate board under heat and pressure and embossed in a laminate press into which a stack of two laminates with a separator between them is introduced so that along longitudinal edges of the stack at least portions remain free when the press is closed for engagement with clamping device of the press discharging unit. As a result, the stack can be engaged while the press is closed so that the opening of the press will not cause relative shifting of the two boards and interfere with the discharge of the press. Once the boards are removed from the press the unpressed portions can be trimmed from the board.

Description

Z0~93~7 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 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.

ZOa~939 182~1 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 .

;2()49397 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 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.

2 0 ~93 97 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~;

~0~ 3397 ~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 1~291 ~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 493~

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~.

Claims

1. A method of making embossed laminate boards, comprising the steps of:
(a) forming a stack of a sandwich structure of two laminates containing a hardenable synthetic resin, and a separating layer between said laminates:
(b) inserting said stack between two press platens of an open single-level platen press having embossing surfaces juxtaposed with opposite faces of said stack and positioning said stack in s id press so that at least along one longitudinal edge of said stack at least spaced apart portions of said stack remain free upon closure of said press;
(c) closing said press, thereby compressing said stack between said surfaces, maintaining said press closed for a period of time sufficient to effect embossing of said opposite faces and hardening of said laminates into boards, and thereupon opening said press;
(d) subsequent to the closing of said press and at least upon opening of said press gripping said portions of said stack with engaging members of a press-discharging unit and, upon opening of said press, withdrawing said boards with said separating layer therebetween from said d press; and (e) thereafter trimming at least said portions from said boards.

2. The method defined in claim 1 wherein said stack is inserted into said press in step b so that all of said longitudinal edge remains exposed upon closure of said press for engagement by said engaging members.

3. The method defined in claim 1 wherein said press platens are chambered to leave said spaced apart process of said stack exposed upon closure of said press.

4. The method defined in claim 1 wherein said stack is inserted into said press by engagement of said stack at an opposite longitudinal edge thereof by engaging members of a stack-inserting unit and at least a portion of said opposite longitudinal edge remains free from closure of said press.

5. The method defined in claim 1 wherein at least spaced apart portions of said stack remain free upon closure of said press along opposite longitudinal edges of said stack.

6. An apparatus for making embossed laminate boards, comprising:
a single-level platen press having two press platens formed with embossing surfaces juxtaposable with opposite faces of a stack of a sandwich structure of two laminates containing a hardenable synthetic resin and a separating layer between said laminates;
means for inserting said stack between said embossing ditgsvrd upon opening of said single-level platen press so that said embossing surfaces are juxtaposed with said opposite faces of said stack and said stack is positioned in said press so that at least along one longitudinal edge of said stack at least spaced apart portions of said stack remain free upon closure of said press; and a press-discharging unit provided with engaging members for gripping said portions of said stack subsequent to the closing of said press and at least upon opening of said press and, upon opening of said press, withdrawing boards formed by compression of side stack between said surfaces and hardening of said laminates, with said separating layer there between from said press.

7. the apparatus defined in claim 6 wherein said press platens are formed with chambers along longitudinal edges thereof leaving said spaced apart portions free upon closure of said press.

8. The apparatus defined in claim 7 wherein said elements are clamps receivable in said chambers.

9. the apparatus defined in claim 8 wherein said surfaces are formed on replaceable embossing plates receiveable in said press and satisfied to be disposed along said platens.