SE193556C1

SE193556C1 -

Info

Publication number: SE193556C1
Authority: SE
Publication date: 1964-01-01

Description

Uppfinnare: M F Fronka Prioritet begtird fran den 10 augusti 1961 (USA) Foreliggande uppfianing hanfor sig gene-relit till Tramstallning av polymerprodukter med skumstruktur. Inventor: M F Fronka Priority begtird from 10 August 1961 (USA) The present invention relates generally to the frame production of polymer products with a foam structure.

Det liar blivit alltmer vanligt att framstalla artiklar sasom modesaker, leksaker, floten, isoleringar och liknande produkter av polymeranaterial med skummad, cellfarmig struktur. Sa.dana artiklar kan lampligen framsthllas pa deft satt, .soan beskrives i den amerikanska patentskriften 2 744 291. Enligt namnda patentskrift placeras expanderbara polymerpartiklar, i vilka inkorporerats 5-15 % jasmedel i en form och upphettas exempelvis genam iniblasning av anga till en temperatur Over jasmedlets kokpunkt men under polymerens smaltpunkt. Under inverkan av var.- met expanderar partiklarna, vaxer ihop och smaller ,sainntan tills formen fylles riled skummat polymermaterial. Forrmen kyles darefter till en temperatur, vid vilken den skumformiga strukturen blir bestfiende och produkten avlagsnas ur formen. It has become increasingly common to produce articles such as fashion items, toys, floats, insulations and similar products from polymeric materials with a foamed, cellular structure. Such articles can be conveniently prepared as described in U.S. Pat. No. 2,744,291. According to the said patent, expandable polymer particles are placed in which 5-15% of blowing agent is incorporated in a mold and heated, for example, by blowing steam into a temperature. Above the boiling point of the blowing agent but below the melting point of the polymer. Under the influence of the heat, the particles expand, grow together and narrow, until the mold is filled with foamed polymeric material. The mold is then cooled to a temperature at which the foamy structure becomes best enemy and the product is removed from the mold.

Expanderbara polymerpartiklar är tillgangliga pa maarknaden under olika handelsnamn, sasom exempelvis jasbar polystyren, soma saljes under varumarkesbeteckningen iDylitem. Jasbara polymerer kan lampligen framstallas pa ,det satt, som beskrives av D'Alelio i den ,amerikanska patentskriften 2 983 692. De expanderbara polymerpartiklarna benamnes »kora» (beads), eftersom de kan expandera mellan 10 och 30 ganger sin ursprungliga storlek. Om expanderade partiklar (virgin particles) anvandes, fylles for-men exempelvis till mindre an en tiondel av sin volym. Pa grund av de expand erade kornens h5ga isolationsformaga medfor detta den nackdelen, att vane korn eventuellt icke blir fullstandigt expanderat, eftersom det joke utsatts for varmen i tillracklig grad. Expandable polymer particles are available on the market under various trade names, such as jasbar polystyrene, which are sold under the iDylitem brand name. Meatable polymers can be conveniently prepared in the manner described by D'Alelio in U.S. Pat. No. 2,983,692. The expandable polymer particles are termed "beads" because they can expand between 10 and 30 times their original size. If expanded particles (virgin particles) are used, the mold is filled, for example, to less than one tenth of its volume. Due to the high insulation capacity of the expanded grains, this has the disadvantage that habitual grains may not be completely expanded, since the joke is exposed to the heat to a sufficient degree.

For avhjalpande av namnda nackdel bru kar man forexpandera kornen, dvs. man upphettar kornen Over jasmedlets kokpunkt men under polymerens smaltpunkt under omrorning utan hindrande auordningar, varvid kornen expanderar till nara slutlig storlek. For-men kan darefter fullstandigt fyllas med de partiellt .expanderade kornen. Vid pafoljande upphettn.ing expanderar kornen vidare, vaxer ihop och smalter saanman till bildning av en massa med forrnens kontur. Masson kyles darefter till en temp eratur, vid vilken polymermaterialet blir sjalvbarande, dvs. behaller sin cellstruktur, nar det avlagsnas ur for-men. Framstallningen av artiklar med skumpolymerstru.ktur innebar vanligen en formningscykel, soma ondattar fOrvarmning av for-men, fyllning ay formen med jasbara polymerartiklar, varmning av partiklarna i for-men och darefter kylning av den resulterande skuraprodukten till en tempera-bur, vid vilken materialet behaller sin skuinstruktur. I en typisk formningscykel fOrdelar sig den under cykeln anvanda tiden pa fOljande satt: fOrvarmning erfordrar omkring 16 % av tidscykeln, pafyllning av .formen kraver omkring 6 % av tiden, uppvarmning av polymerpartiklarna tager omkring 2 % av tiden, medan for kylning av den fardiga produkten, sa att den kan avlagsnas ur formen, 'AUL' oartkring 76 % av tiden. Kylningen av den fardiga produkten varierar och beror av artikelns form och storlek saint tatheten hos den resulterande sktmistrukturen. Under i ovrigt lika betingelser kommer formgods med hogre tat-het att fordra langre kyltid an sadant med lagre tathet och gods med tjockare tvarsnitt att krava langre kyltid an sadant med tunnare. Om former', Oppnas innan skalet har hardnat eller den inre .delen kylts ned tillrackligt, kommer en efterexpansion att intriffa resulterande i distorsion av det for- 2— — made foremalet. Eftersom skurnpolymermaterial är eri utmarkt varmeisolator, är kylningsdelen i cykeln uteslutande det langsta steget i formningsproceduren. Medan ovriga delar i formningsprocessen forloper ph nagra sekunder kan kylningsdelen krava sh anycket som flera minuter. To remedy the aforementioned disadvantage, one can forexpander the grains, ie. the grains are heated above the boiling point of the blowing agent but below the melting point of the polymer with stirring without obstruction, whereby the grains expand to near final size. The mold can then be completely filled with the partially expanded grains. Upon subsequent heating, the grains expand further, grow together and melt together to form a mass with the contour of the furnace. Masson is then cooled to a temperature at which the polymeric material becomes self-supporting, i.e. retains its cellular structure when it is removed from the mold. The production of articles having a foam polymer structure usually involved a molding cycle, which was intended to preheat the mold, fill the mold with fermentable polymeric articles, heat the particles in the mold and then cool the resulting scrubbing product to a temperature cage at which the material retains its oblique structure. In a typical forming cycle, the time used during the cycle is distributed as follows: preheating requires about 16% of the time cycle, filling the mold requires about 6% of the time, heating the polymer particles takes about 2% of the time, while cooling the finished the product, so that it can be removed from the mold, 'AUL' around 76% of the time. The cooling of the finished product varies and depends on the shape and size of the article and the tightness of the resulting mold structure. Under otherwise equal conditions, molded goods with higher density will require longer cooling time than those with lower density and goods with thicker cross-sections will require longer cooling time than those with thinner. If molds are opened before the shell has hardened or the inner part has cooled down sufficiently, a subsequent expansion will occur resulting in distortion of the molded mold. Since scouring polymer material is an excellent thermal insulator, the cooling part of the cycle is exclusively the longest step in the molding procedure. While other parts of the forming process take a few seconds, the cooling part may require as little as several minutes.

Det har nu befunnits, att langden pa kylningsdelen i cykeln kan minskas i stor utstrackning genom behandling av de forexpanderade kornen enligt uppfinningen innan de fylles pa formen. Denna behandling omfattar for-jasning av kornen till en forutbestamd skrymdensitet, krossning av de just for-jasta kornen och darefter fornyad jasning av de krassade kornen till onskad skrymdensitet. Derma behandling ger expanderade korn, som latt ,formas men kraver 40-60 % mindre tid i kylningsdelen at cykeln an som normalt erfordras, innan godset kan avlagsnas ur for-men i sjalvbarande tillstand. It has now been found that the length of the cooling part of the cycle can be greatly reduced by treating the forexpanned grains according to the invention before they are filled into the mold. This treatment comprises pre-fermenting the grains to a predetermined bulk density, crushing the just-pre-grained grains and then re-fermenting the crushed grains to the desired bulk density. This treatment gives expanded grains, which are easily formed, but requires 40-60% less time in the cooling part than the bicycle normally requires, before the goods can be removed from the mold in a self-supporting condition.

Enligt foreliggande uppfinning astalkommes ett forfarande for behandling av jasbara polymerpartiklar, sá att den erforderliga tiden for kylningsdelen i .formningscykeln minskas, vilket forfarande omfattar partiell expansion av polymerpartiklarna, krossning av partiklama och darefter fornyad partiell expansion av partiklama. According to the present invention, there is provided a method of treating fermentable polymer particles so as to reduce the time required for the cooling portion of the forming cycle, which method comprises partial expansion of the polymer particles, crushing of the particles and then renewed partial expansion of the particles.

Foreliggande uppfinning avser aven framstallning av jasta polymerpartiklar, som behandlats enligt den ,angivna metoden. The present invention also relates to the preparation of yeast polymer particles which have been treated according to the method indicated.

For att uppfinningen skall kunna lattare Rastas och praktiseras, beskrives densamma nedan mar detaljerat under hanvisning till bifogad ritningsfigur, vilken schematiskt illustrerar apparaturen for utforandet av forfarandet enligt uppfinningen. In order that the invention may be more readily practiced, the same is described in more detail below with reference to the accompanying drawing figure, which schematically illustrates the apparatus for carrying out the method according to the invention.

Det i ritningsfiguren visade systemet omfattar generellt tvd serieforbundna fOr-jasare ,och 11, en. forvaringsbehallare 12 och en form 13. En ledning 15 forbinder for-jasarna och 11, en ledning 19 forbinder for-jasaren 11 tried forvaringsbehallaren 12 och en ledning 21 forbinder forvaringsbehallaren 12 med formen 13. The system shown in the drawing figure generally comprises two series-connected pre-jasers, and 11, one. storage container 12 and a mold 13. A conduit 15 connects the pre-jacks and 11, a conduit 19 connects the pre-jacket 11 to the storage container 12 and a conduit 21 connects the storage container 12 to the mold 13.

Anginblasningsroren 27A och 27B matar korn av jasbar polymer Iran matartrattarna 23A och 23B genom ledningarna 25A och 25B in i for-jhsaren. I allmanhet utg8res den angvarmda for-jasaren av ett isolerat, cylindriskt karI av rostfritt sto, i vilket en axiell omrorare av rostfritt sta.]. drives ,av en motor. Omroraren utgores av en axel utrustad med radiellt utgaende omrorarstanger. Fasta horisontella stanger anbragta pa cylindern griper in mellan omrorarstangerna. Anga och jasbarn polymerpartiklar inkommer i karlet vid dess batten. Da de jAsbara polymerpartiklarna inkommer i karlet expanderar de pa grand av varmet fran h.ngan och undantranger de mer fullstandigt jasta partiklarna och tyingar pa sa ,saft de jasta partiklarna att rora sig uppat och matas ut genom overflodesrannor na 29A och 29B. Kamen artdrar tathet alit eftersam de expanderar eller biases upp. Motorerna 31A och 31B astadkommer =naming av kornen, for fOrhindrande av clessas agglomeration under denna del ay jasningsprocessen. The blow-in tubes 27A and 27B feed granules of jasbar polymer Iran feed hoppers 23A and 23B through the conduits 25A and 25B into the preheater. In general, the heated preheater consists of an insulated, cylindrical vessel of stainless steel, in which an axial stirrer of stainless steel. driven, by an engine. The stirrer consists of a shaft equipped with radially extending stirrer rods. Fixed horizontal rods mounted on the cylinder engage between the stirrer rods. Anga and jasbarn polymer particles enter the vessel at its batten. As the fermentable polymer particles enter the vessel, they expand to a great extent by the heat from the hanger and displace the more completely fermented particles and so on, allowing the fermented particles to move upwards and be discharged through overflow channels 29A and 29B. Kamen speciesdrar tathet alit eftersam they expand or biases up. The motors 31A and 31B provide for the removal of the grains, to prevent the agglomeration of the grains during this part of the fermentation process.

Enligt uppfinningen bringas de partiellt jasta polymerpartiklarna if ran rannan 29A att passera mellan krossvalsarna 37, efter vilket de matas vidare till for-jasaren 11, ddr de krossa:de konnen ater expanderas. According to the invention, the partially fermented polymer particles from the groove 29A are caused to pass between the crushing rollers 37, after which they are passed on to the pre-mixer 11, where the crushed cans are expanded.

Valsarna 37 kan vara lath och ihaliga. Exempelvis hat valsar av diametern 30 cm och langden 60 cm framstallda av gjutna rostfria stalror befunnits tillfredsstallande. Valsarna kan drivas at en konventionell elektrisk motor och exempelvis framdrivas at en drivkalla ph 3/4 hhstkraft ,med variabel hastighet. En valshastighet ph 110 vary per minut medger krossning av korn med en tathet av 16-32 g/dm3. The rollers 37 may be lath and hollow. For example, rollers 30 cm in diameter and 60 cm long made of cast stainless steel have been found to be satisfactory. The rollers can be driven by a conventional electric motor and, for example, driven by a driving cold ph 3/4 hhst power, with variable speed. A rolling speed ph 110 vary per minute allows crushing of grains with a density of 16-32 g / dm3.

Det är viktigt, att de for-jasta kornen icke krossas fifir inycket. For erhallande av basta resultat bOr skrymdensiteten ph de for-jasta kornen ej okas rner an tva och en halt gang under krossningssteget. Om man t. ex. onskar forma ett material med tathet 16 g/dms, bar de oexpanderade km-nen jasas till en tathet ay 16 gidm3 i jasaren ,och darefter krossas till en tathet av 32-40 g/dm3. Darefter jases materialet hter till en tathet av 16 g/dm3. It is important that the pre-fermented grains are not crushed beforehand. In order to obtain the best results, the bulk density of the pre-fermented grains should not be increased by two and a half times during the crushing step. If one e.g. wanting to form a material with a density of 16 g / dms, the unexpanded km were jasmed to a density of 16 gidm3 in the jasper, and then crushed to a density of 32-40 g / dm3. Then the material is heated to a density of 16 g / dm 3.

Eftersom kornen expanderar hastigt i jasaren 11 imnatas Tuft genom en ledning 35 tillsammans Hied angan for att minska dei varmemangd, som overfores till kornen och for att minska komens uppehallstid i forjasaren. Overflodet fran r5.nnan 29B pa forjasaren 11 ledes site deist ledningen 19 till forvaringsbehallaren 12, dar partiklarna lampligen fddras. Under aldrandet forblir partiklarna i behallaren 6 till 10 tinunar, varunder de synbarligen blir fyllda med atmosfarisk luft. Genom en sacian aldring undviker man. krympning av skumprodukten fran. formen. As the grains expand rapidly in the blast furnace 11, Tuft is fed through a conduit 35 together to reduce the heat transfer to the grains and to reduce the residence time of the grains in the blast furnace. The overflow from the pipe 29B on the blower 11 is routed to the site 19 to the storage container 12, where the particles are suitably fed. During aging, the particles remain in the container 6 to 10 thaws, during which they are apparently filled with atmospheric air. Through a sacian aging one avoids. shrinkage of the foam product from. the form.

Partiklarna phfylles darefter en form 13 ay onskad. kontur. Fanmen 13 kan vara av kanventionell typ, exempelvis en sadan, som beskrives ph sidan 3B i broschyren »Dylite>> tryckt 1953 i USA. Anga, som inledes i for-men far partiklarna aft expandera, smalta samman och vaxa ihop till bildning av ett foremal i overensstammelse med formens utseende. Foremalet kyles darefter tills det kommit ned i en temperatur tillraeklig fOr att skumstrukturen skall hibehallas. Artikeln aylagsnas darefter ur formen. Den erforderliga smalttiden for formning ay de krossade och for-jasta kornen Or identisk med den lid, som fordras for normalt okrossat material. Det oaktat resulterar behandlingen enligt uppfinningen av kornen en. kylningstidsreduktion ph narmalt 50 % i jamfdrelse med standardtekniken. The particles are then filled into a mold 13 ay unwanted. contour. Fanmen 13 may be of the conventional type, for example one such as described on page 3B of the brochure "Dylite" printed in 1953 in the USA. The form which is introduced into the mold causes the particles to expand, fuse together and wax together to form a mold in accordance with the appearance of the mold. The form is then cooled until it has come down to a temperature sufficient for the foam structure to be maintained. The article is then removed from the form. The required melting time for forming the crushed and pre-fermented grains is identical to that required for normally uncrushed material. Nevertheless, the treatment according to the invention of the grains results one. cooling time reduction ph narmalt 50% in comparison with the standard technique.

For att askadliggOra uppfinningen forvarm- — —3 des en form for 'framstallning av skumpolyinermaterial med dimensionen 30X30X5 cm i 35 sekunder och fylldes sedan med forexpanderad, jastbar polystyren (skid under handelsnanmet »Dylite») samt upphettades med anga pa konventionellt Ott. Tiden, sem atgiek for pAfyllning av formen med jasbar polystyren, var 15 sekunder och tiden under vilken for-men uppyaraudes genom paslapp av anga 6 till 8 ,sekunder. Artikeln kyldes clarefter tills materialet kunde avlagsnas utan kollaps eller vidareexpansion av skumprodukten. Nedan angives kyltiderna for partiklar av jasbar polystyren, vilka behandlats enligt uppfinningen. In order to damage the invention, a form of production of foam polyiner material measuring 30x30X5 cm was heated for 35 seconds and then filled with forexpanded, adjustable polystyrene (ski under the trade name "Dylite") and heated with conventional oil. The time required to fill the mold with jasbar polystyrene was 15 seconds and the time during which the mold was raised by a pass slip of about 6 to 8 seconds. The article was then cooled until the material could be deposited without collapse or further expansion of the foam product. The cooling times for particles of jasbar polystyrene, which have been treated according to the invention, are given below.

Forexpan- Ex.derad, tat- gl dm' 32 6 2 16 32 2 3 16 4 16 16 2 Skillnaden. visas ocksa 1 foljande exempel, i vilka 30 cm kuber formades 16 _ ____ 17 6 16 36 16 7 7 16 _ _ 14 I det foregaende har angivits en ny metod for framstallning av foremal med skumpolymerstruktur. Enligt fOreliggande upp finning Ran en normal forms produktionskapacitet okas genom minskning av den kyltid som er fordras for ,att formgodset skall bibehalla sin skumstruktur. Forexpan- Ex.derad, tat- gl dm '32 6 2 16 32 2 3 16 4 16 16 2 The difference. 1 is also shown in the following examples, in which 30 cm cubes were formed 16 _ ____ 17 6 16 36 16 7 7 16 _ _ 14 In the foregoing, a new method for producing molds with foam polymer structure has been given. According to the present invention, the production capacity of a normal mold is increased by reducing the cooling time required for the molded material to maintain its foam structure.

Claims

Patent claim:

A method of treating fermentable polymer particles to reduce the time required. for kytningsdeleu i formningseykela, kannetecknat av alt polymerparitiklarna partial jases, krossas och thereafter Ater partial jases.

2. A method according to claim 1, characterized in that the particles are crushed to a Whet of 2.5 times the partially fifth particles.

Method according to claim 1 or 2, characterized in that the particles are crushed indistinguishably after the partial fermentation and while the particles are still selected.

4. A process according to any one of the preceding claims, characterized in that the particles, after being crushed and partially fermented, are filled into a desired contour and heated to a temperature above the boiling point of the jam but below the melting point of the particles and the resulting foam product is cooled and a-vliigsnas ur formen. Listed publications: