IT8323278A1

IT8323278A1 - EQUIPMENT AND PROCEDURE FOR COATING THE ENDS OF STEEL AND / OR ALUMINUM OF JARS WITH A SEALANT COMPOUND

Info

Publication number: IT8323278A1
Application number: IT1983A23278A
Authority: IT
Original assignee: Grace W R & Co
Priority date: 1982-10-14
Filing date: 1983-10-12
Publication date: 1985-04-12
Also published as: ES516492A0; IT8323278A0; AU1955183A; ES8308721A1; IT1171756B; PH22603A; BR8305604A; AU563618B2; MX160806A; JPS5993606A; NZ205834A

Description

DESCRIZIONE DESCRIPTION

La presente descrizione riguarda una apparecchiatura ed un procedimento per sigillare coperchi, "barattoli di acciaio e/o alluminio con un composto sigillante, atti ad essere impiegati nella fabbricazione di barattoli o "lattine". The present description relates to an apparatus and a process for sealing lids, "cans of steel and / or aluminum with a sealing compound, adapted to be used in the manufacture of cans or" cans ".

Tradizionalmente i barattoli metallici per bevande, cibi ed altri prodotti sono stati ricavati da un corpo cilindrico Bui quale vengono serrati due elementi di chiusura (generalmente noti come coperchi del barattolo) , uno a ciascuna estremit?# Il produttore del barattolo provvede a serrare in posizione uno dei coperchi del barattolo ed invia i barattoli vuoti ed i coperchi per la sommit? dei barattoli al confezionatore. Una volta che i barattoli siano stati riempiti con il prodottogli confezionatore provvede al serraggio dell'altro coperchio. In questi ultimi anni barattoli cosiddetti in due pezzi sono stati introdotti e largamente adottati. Con questo tipo di barattolo, il corpo ed uno Traditionally, metal cans for drinks, food and other products have been obtained from a cylindrical body where two closing elements (generally known as can lids) are tightened, one at each end. one of the lids of the jar and send the empty jars and lids to the top? of the jars to the packer. Once the cans have been filled with the product, the packer tightens the other lid. In recent years so-called two-piece cans have been introduced and widely adopted. With this type of jar, the body and one

dei coperchi vengono formati come un pezzo unico per mezzo di un processo di imbutitura e formatura della parete oppure di imbutitura e re-imbutitura/per cui non si richiede che un solo coperchio per il barattolo. In qualsiasi tipo di barattolo, il coperchio del barattolo fornisce una chiusura ermetica al corpo del barattolo, onde prevenire l'ingresso di batteri o la dispersione del contenuto del barattolo. Per ottenere detta chiusura ermetica ? necessario rivestire il canale del coperchio del barattolo con un materiale (generalmente noto come composto sigillante od ermetizzante")# Questa operazione viene eseguita dal produttore del barattolo durante il processo di fabbricazione dei coperchi. Il materiale viene applicato al canale del coperchio del "barattolo in forma liquida iniettandolo entro il canale Btessot quando quest'ultimo gira ad alta velocit? in modo che la forza centrifuga consenta una opportuna distribuzione del composto sigillante nel canale del coperchio. Lids are formed as a single piece by means of a deep drawing and wall forming or drawing and re-drawing process whereby only one lid is required for the can. In any type of jar, the jar lid provides an airtight seal to the jar body to prevent bacteria from entering or dispersing the jar contents. To obtain this hermetic seal? It is necessary to coat the can lid channel with a material (generally known as a "sealing or sealing compound") # This is done by the can manufacturer during the lids manufacturing process. The material is applied to the "can in liquid form injecting it into the Btessot channel when the latter rotates at high speed? so that the centrifugal force allows a proper distribution of the sealing compound in the lid channel.

I composti sigillanti o ermetizzanti possono essere di due tipi, che sono convenzionalmente noti come composti a base di acqua e composti a base di solvente? Il composto a base di acqua consiste in una dispersione dei componenti del materiale in acqua^mentre il composto a ba*-se di solvente consiste in una soluzione di alcuni dei componenti ed in una dispersione di altri in un mezzo liquido organico, di solito esano* Dopo cheil coperchio del barattolo sia stato sigillato con il composto liquido ? necessario separare la fase liquida per poter ottenere un giunto solido. Nel caso dei composti a base di solventi ci? si effettua semplicemente lasciando evaporare l'esano in condizioni ambiente* Nel caso dei composti a base di acqua,tradizionalmente il composto sigillante veniva essiccato mediante applicazione di calore facendo passare i coperchi previamente sigillati attraverso un forno di qualche tipo? Generalmente si impiegano due tipi di forno, noti come forno a tunnel e forno verticale. Can sealing or sealing compounds be of two types, which are conventionally known as water-based compounds and solvent-based compounds? The water-based compound consists of a dispersion of the components of the material in water while the solvent-based compound consists of a solution of some of the components and a dispersion of others in an organic liquid medium, usually hexane. * After the lid of the jar has been sealed with the liquid mixture? it is necessary to separate the liquid phase in order to obtain a solid joint. In the case of solvent-based compounds there? it is done simply by letting the hexane evaporate under ambient conditions. Generally two types of kiln are used, known as tunnel kiln and vertical kiln.

II forno a tunnel ? costituito da un lungo forno riscaldato mediante aria calda, proveniente di solito da un bruciatore a gas, con un nastro trasportatore che attraversa il forno* Pile di coperchi vengono disposte sul nastro e quindi convogliate attraverso il forno, di regola per un tempo di permanenza o trascorrenza di 20 minuti* All'uscita dal forno, le pile di coperchi vengono separate a mano ed immagazzinate in un qualsiasi modo opportuno per l 'uso interno allo stabilimento o per la spedizione al confezionatore? The tunnel oven? consisting of a long oven heated by hot air, usually coming from a gas burner, with a conveyor belt running through the oven * Piles of lids are placed on the belt and then conveyed through the oven, usually for a residence time or 20 minutes * After leaving the oven, are the stacks of lids separated by hand and stored in any suitable way for internal use in the factory or for shipment to the packer?

Il forno a vite ? costituito da coppie di viti senza fine ruotanti che sono disposte verticalmente e contenute entro im forno ad aria calda? I coperchi dei barattoli vengono alimentati dalla macchina sigillatrice dove il' composto ? gi? stato applicato automaticamente alle viti senza fine , ed il movimento giratorio di queste ultime convoglia i coperchi verticalmente , i coperchi venendo separati dal passo del filetto delle viti ? Il tempo di permanenza in un forno a vite ? generalmente di 4 minuti ? La lunghezza consueta delle viti verticali ? quella necessaria a dare un tempo di trasporto di 1 minuto per ciascun coperchio di barattolo, dal fondo alla sommit? delle viti . Pertanto, i forni di questo tipo presentano generalmente quattro serie di viti^con serie alternate a filettatura destrorsa e filettatura sinistrorsa? I coperchi dei barattoli vengono trasferiti meccanicamente dalle estremit? di una serie di viti all'inizio della serie successiva? In corrispondenza dell'uscita dal forno i coperchi vengono alimentati automaticamente per essere infilati secondo una disposizione prefissata, di dove vengono prelevati manualmente per l'utilizzazione nello stabilimento o per la spedizione al confezionatore? The screw oven? consisting of pairs of rotating worm screws which are arranged vertically and contained within a hot air oven? The lids of the cans are fed from the sealing machine where the 'compound? already? been applied automatically to the worm screws, and the rotational movement of the latter conveys the covers vertically, the covers being separated by the thread pitch of the screws? The residence time in a screw oven? generally 4 minutes? The usual length of vertical screws? the one necessary to give a transport time of 1 minute for each jar lid, from the bottom to the top? screws. Therefore, furnaces of this type generally have four series of screws with alternating series with right-hand thread and left-hand thread? The lids of the jars are transferred mechanically from the ends? of one set of screws at the beginning of the next set? At the exit from the oven, the lids are automatically fed to be inserted according to a predetermined arrangement, from where are they manually taken for use in the factory or for dispatch to the packer?

Il forno del tipo a tunnel risulta meccanicamente affidabilissimo, poich? ? costituito semplicemente da un nastro trasportatore che attraversa il forno stesso, ma richiede un ingente apporto di manodopera in quanto le pile di coperchi devono essere caricat e manualmente in corrispondenza di una estremit? e raccolte in corrispondenza dell'altra estremit?* I forni del tipo a vite non richiedono un intervento di manodopera altrettanto ingente, ma per contro sono estremamente suscettibili di avarie meccaniche principalmente a motivo del meccanismo di trasferimento dei coperchi di barattolo da una serie di viti alla serie successiva? Questi problemi meccanici rappresentano una perdita di tempo operativo e riducono perci? l?efficienza globale del processo di fabbricazione dei coperchi? The tunnel type oven is mechanically very reliable, since? ? consists simply of a conveyor belt that crosses the oven itself, but requires a large amount of manpower as the stacks of lids must be loaded manually at one end? and collected at the other end * The screw type ovens do not require as much labor, but on the other hand they are extremely susceptible to mechanical failures mainly due to the mechanism of transfer of the can lids by a series of screws to the next series? These mechanical problems represent a waste of operational time and therefore reduce? the overall efficiency of the lids manufacturing process?

Nel caso dei composti a base di solvente , questi non richiedono alcun tipo di forno, poich? i coperchi vengono trasferiti automaticamente dalla macchina sigillatrice ad un breve impianto trasportatore, e dal trasportatore i coperchi vengono trasferiti manualmente ad una forma qualsiasi di imballaggio idoneo a consentirne l' inqpiego nello stabilimento o la spedizione al confezionatore? La maggior parte del solvente organico evapora mentre i coperchi di barattolo si trovano sull?impianto traspoiN-tatore e la piccola quantit? che ne rimane evapora durante il mag&zzinaggio. In the case of the solvent-based compounds, these do not require any type of oven, as they are Are the lids automatically transferred from the sealing machine to a short conveyor system, and from the conveyor are the lids manually transferred to any form of packaging suitable for use in the factory or shipping to the packer? Most of the organic solvent evaporates while the jar lids are on the conveyor system and the small amount of water evaporates. what remains of it evaporates during storage.

Dalla descrizione sopra fornita apparir? evidente come composti a base di solvente siano il tipo di composto pi? idoneo all 'uso dal punto di vista del produttore dei barattoli? Tuttavia, la presenza del solvente organico costituisce un problema nei paesi nei quali vigono leggi concer nenti la tossicologia ambientale e le condizioni di sicurezza sul posto di lavoro? Ovviamente si ha vapore di esano nell' atmosfera circondante la macchina rivestitrice e la concentrazione di esano ammissibile nell'aria ? in molti paesi oggetto della legislazione? Inoltre in molti paesi esistono limiti concernenti la quantit? di vapore organico che pu? essere emesso da un irrqpianto, come ad esempio quello proveniente da vernici a base di solvente e composti sigillanti per barattoli? Pertanto molti paesi stanno abbandonando l'uso dei comporti a base di solvente? Tuttavia esi^ ste una notevole resistenza da parte dei fabbricanti per quanto rigiarda la conversione ai forni per l'essiccazionedi composti a base di acquat cui si associano i problemi Bopra citati? Inoltre, anche i fabbricanti di barattoli che usano generalmente composti a base di acqua con forni convenzionali conseguirebbero vantaggi notevoli se potessero fare a meno di questi forni? From the description provided above will appear? evident how solvent-based compounds are the type of compound pi? suitable for use from the can manufacturer's point of view? However, is the presence of the organic solvent a problem in countries with laws regarding environmental toxicology and safety conditions in the workplace? Obviously there is hexane vapor in the atmosphere surrounding the coating machine and the permissible concentration of hexane in the air? in many countries subject to legislation? Furthermore, in many countries there are limits on the quantity? of organic vapor that can? be emitted by an irrigator, such as that from solvent-based paints and sealing compounds for cans? So many countries are abandoning the use of solvent-based behaviors? However, is there considerable resistance on the part of manufacturers regarding the conversion to the kilns for the drying of aquat-based compounds associated with the Bopra problems mentioned? In addition, would can makers who generally use water-based compounds with conventional ovens also reap significant benefits if they could do without these ovens?

In vista di queste considerazioni, ? stato messo a punto un nuovo tipo di conqposto a base di acqua con un elevato tenore di solidi, il (piale pu? essere essiccato senza dover far uso di un forno, mentre fornisce anche un giunto con tutte le caratteristiche per una soddisfacente sigillatura ermetica dei barattoli? Tuttavia/nonostante il fatto che questo composto pu? essere essiccato all'aria, il tempo necessario per essiccare il giunto dipende in larga misura dalle condizioni ambiente nello stabilimento di fabbricazione dei barattoli, cio? dalla temperatura e dall'umidit? relativa dell'aria, nonch? dal procedimento con il quale i coperchi di barattoli vengono imballati e raagazzinati dopo l'operazione di sigillatura. Data chiesta limitazione l'invenzione concern e un procedimento sviluppato per eliminare questa incertezza per quanto riguarda il tempo di essiccazione senza dover far ricorso ad un convenzionale forno? Il presente processo combina perci? i vantaggi dell'agevole manipolazione di un composto a base di solvente, con i vantaggi di un composto a base d'acqua per quanto riguarda la tossicit? e la contaminazione ambientale? In view of these considerations,? A new type of water-based compound with a high solids content has been developed, the pial can be dried without having to use an oven, while also providing a joint with all the characteristics for a satisfactory hermetic sealing of the However / despite the fact that this compound can be dried in air, the time it takes to dry the joint depends to a large extent on the ambient conditions in the can manufacturing plant, i.e. the temperature and relative humidity of the can. air, as well as from the process by which the lids of cans are packaged and stored after the sealing operation. Given the requested limitation, the invention concerns a process developed to eliminate this uncertainty regarding the drying time without having to make using a conventional oven - this process therefore combines the advantages of easy handling of a solvent-based compound , with the advantages of a water-based compound in terms of toxicity? and environmental contamination?

Il concetto su cui si basa questo procedimento prevede il riscaldamento dei coperchi prima che essi vengano sigillati in modo che il composto venga applicato ad un coperchio pre-ri se aidato* Se il coperchio ? sufficientemente caldo, parte dell' acqua presente nel composto evapora immediatamente all'atto dell' applicazione del composto al coperchio, e la maggioranza dell'acqua evapora mentre i coperchi vengono trasferiti lungo l'impianto trasportatore che ? simile a quello usato con il composto a base di solvente? Di conseguenza, quando i coperchi vengono rimossi dall' im pianto trasportatore e imballati per l' immagazzinaggio, l?umidit? rimanente nel giunto ? sufficientemente bassa da permettere alla rimanenza di evaporare durante il magazzinaggio entro un breve periodo di tempo? The concept on which this procedure is based involves heating the lids before they are sealed so that the compound is applied to a pre-supplied lid. * If the lid? sufficiently hot, part of the water present in the compound evaporates immediately upon application of the compound to the lid, and the majority of the water evaporates while the lids are transferred along the conveyor system which? similar to that used with the solvent-based compound? Consequently, when the lids are removed from the conveyor system and packed for storage, the humidity is remaining in the joint? low enough to allow the remainder to evaporate during storage within a short period of time?

A motivo del fatto che i coperchi vengono riscaldati prima della sigillatura anzich? dopo la sigillatura, come si verifica nel caso dei forni convenzionali, il processo ? noto come di "pre-riscaldamento", e l'unit? che provvede a riscaldare i coperchi ? nota come "pre-riscaldatore"? Si potrebbe concludere che non si ha vantaggio nel riscaldare i coperchi prima della loro sigillatura anzich? dopo? Tuttavia, non ? (questo il caso*Nel processo convenzionale,, se il processo di essiccazione del composto sigillante si svolge repentinamente a temperatura altissima nell'arco di un breve periodo di tempo, il composto tende a formare vescicole? Ci? si deve al fatto che la superficie del composto essicca per prima formando una cort?ccia che impedisce l'evaporazione dell' acqua dall' interno e provoca perci? la formazione di vescicole sotto la corteccia? Di conseguenza esiste un limite per quanto riguarda la rapidit? di essiccazione dei coperchi sigillati in un forno, il che significa che esistono limiti alla temperatura impiegabile? Inoltre, con i convenzionali corrqjosti a base d'acqua ? necessario accertarsi che il composto sigillante sia completamente seoco quando i coperchi lasciano il forno? Queste limitazioni impongono un limite minimo alle dimensioni del forno? Tuttavia, con l'unit? pre-riscaldatrice, e dato che i coperchi non sono sigillati quando vengono riscaldati; non si hanno limiti alla velocit? alla quale essi possono essere riscaldati, e pertanto il riscaldamento pu? essere effettuato con tutta la rapidit? necessaria, in modo che l'unit? possa essere fabbricata in ima forma completamente compatta. L'unit? pre-riscaldatrice pu? essere installata sopra ?* apparecchiatura esistente usata per la sigillatura dei coperchi di barattoli, in luogo della macchina nel punto in cui i coperchi vengono alimentati all' interno della macchina; il che significa che non occorre ulteriore spazio a pavimento, come nel caso del forno? Due to the fact that the lids are heated before sealing instead of? after sealing, how does the process take place in the case of conventional ovens? known as "pre-heating", and the unit? who warms the lids? known as "pre-heater"? Could it be concluded that there is no advantage in heating the lids prior to sealing them instead? after? However, don't you? (this is the case * In the conventional process, if the drying process of the sealing compound takes place abruptly at very high temperatures over a short period of time, does the compound tend to form vesicles? of the compound dries first, forming a cortex that prevents the evaporation of water from the inside and therefore causes the formation of vesicles under the bark? Consequently there is a limit regarding the speed of drying of the sealed lids. an oven, which means there are limits to the usable temperature? Also, with conventional water-based corrqjosti? you need to make sure that the sealing compound is completely dry when the lids leave the oven? These limitations impose a minimum limit on the size of the oven. However, with the pre-heater unit, and since the lids are not sealed when heated; there is no limit to the speed ocit? to which they can be heated, and therefore the heating can? be carried out with all the rapidity? necessary, so that the unit? can be manufactured in a completely compact form. The unit pre-heater pu? be installed on top of? * existing equipment used for sealing can lids, in place of the machine at the point where the lids are fed into the machine; which means that there is no need for additional floor space, as in the case of the oven?

A seconda di se i coperchi sono di acciaio o di alluminio, vengono impiegate due configurazione diverse di pre-riscaldatore. In entrambi i casi i coperchi vengono riscaldati dall 'azione di aria calda su di essi, l'aria calda provenendo da un ventilatore dopo essere passata attraverso resistenze elettriche? Nel caso dei coperchi di acciaio e a motivo della bassa conduttivit? termica dell ' acciaio ? necessario separare i coperchi in modo che possa essere soffiata aria calda fra di essi? Ci? si ottiene usando una tramoggia magietica? La tramoggia magietica consiste in un tubo cilindrico d'acciaio inossidabile con una serie di magieti permanenti disposti su entrambi i lati del tubo? Il cangio magietico creato fra i due magieti induce magietismo nei coperchi di acciaio, per cui essi si respingono reciprocamente e vengono automaticamente separati* La distanza fra i singoli coperchi pu? essere regolata per mezzo della separazione dei ma^ieti? I coperchi vengono rimossi dal fondo di questa tramoggia magietica mediante il meccanismo di avanzamento della macchina sigillatrice e alimentati alla stazione di sigillatura, mentre al tempo stesso i coperchi vengono alimentati in alto da un nastro trasportatore che procede dalla pressa che produoe i coperchi* Durante il passaggio dalla sommit? alla base della tramoggia magietica i coperchi vengono riscaldati da aria calda che viene soffiata attraverso di essi? Depending on whether the lids are made of steel or aluminum, two different pre-heater configurations are used. In both cases the lids are heated by the action of hot air on them, the hot air coming from a fan after passing through electrical resistances? In the case of steel covers is it because of the low conductivity? thermal of steel? need to separate the lids so that hot air can be blown between them? There? is obtained by using a magic hopper? Does the magietic hopper consist of a cylindrical stainless steel tube with a series of permanent magieties arranged on both sides of the tube? The magietic change created between the two magieties induces magietism in the steel lids, whereby they repel each other and are automatically separated * The distance between the individual lids can? be regulated by means of separation of the heaths? The lids are removed from the bottom of this magic hopper by the feed mechanism of the sealing machine and fed to the sealing station, while at the same time the lids are fed at the top by a conveyor belt which proceeds from the press that produces the lids * passage from the top? at the base of the magic hopper are the lids heated by hot air which is blown through them?

Nel caso di coperchi di alluminio; e a motivo della loro molto maggiore conduttivit? temica rispetto ai coperchi di acciaio, non ? necessario provvedere a separarli e, pertanto, il pre-riscaldator.e per coperchi di alluminio consiste essenzialmente in una incamiciatura cilindrica isolata entro la quale viene soffiata lateralmente aria calda, che fuoriesce poi dalla sommit?# Una serie di paratie viene usata all'intexno di questa camera cilindrica allo scopo di assicurare la corretta circolazione dell' aria? In entrambi i tipi di pre-riscaldatore , l'aria calda che fuoriesce dal pre-ri scaldatone pu? essere riciclata alla soffiante allo scopo di migliorare l'efficienza termica globale del processo? In the case of aluminum lids; and because of their much greater conductivity? temica compared to steel lids, isn't it? it is necessary to separate them and, therefore, the pre-heater. for aluminum lids essentially consists of an insulated cylindrical jacket into which hot air is blown sideways, which then comes out from the top. # A series of bulkheads is used inside of this cylindrical chamber in order to ensure correct air circulation? In both types of pre-heater, the hot air that escapes from the pre-heater can? be recycled to the blower in order to improve the overall thermal efficiency of the process?

Nel caso del pre-ri scaldato re per coperchi di acciaio , il trasfer? merimento di calore dall'aria calda ai coperchi dipende in larga misura dalla separazione fra i coperchi? Di conseguenza, per assicurare un buon controllo della tenqjeratura ? necessario controllare con precisione questa separazione* Il normale criterio di esercizio della macchina sigillatrice che viene alimentata automaticamente con coperchi da una pressa, consiste nel fare operare la macchina sigillatrice ad una velocit? leggermente superiore a quella della pressa; per esempio^ se la pressa produce 300 coperchi al minuto, la macchina sigillatrice verr? regolata per produrre 310 coperchi al minuto? L' alimentazione dei coperchi dalla sigillatrice prevede la presenza di rivelatori di prossimit? per rilevare l' altezza della pila di coperchi? Quando la pila raggiunge un limite inferiore fissato, l' alimentazione dei coperchi dalla pila alla stazione di sigillatura viene automaticamente ritardata finche la fine della pila raggiunge un limite superiore fissato? In questo modo la pressa opera in continuit?^ma la macchina sigillatrice opera ad intermittenza? Ovviamente ? possibile far combaciare la velocit? delle due apparecchiature con esattezza? E' pi? difficile far operare ad intermittenza una pressa ed ? preferibile che la macchina sigillatrice operi pi? rapidamente della pressa, anzich? il contrario? Quando detto impianto viene usato con il p re-ri scaldato re per coperchi di acciaio, il numero dei coperchi nella tramoggia magnetica varia in continuit?, il che fa a sua volta variare la separazione fra i singoli coperchi? Per poter risolvere questo problema ? stato sviluppato un<? >contatore elettronico bidirezionale che opera nel seguente modo; un rivelatore di prossimit? rivela i coperchi mano a mano che i coperchi vengono alimentati alla parte superiore della tramoggia magnetica, mentre l'altro rivelatore di prossimit? rivela i coperchi mano a mano che questi lasciano la macchina sigillatrice? Il numero di coperchi richiesto viene alimentato nel pre-riscaldatore per fornire la nfecessaria separazione fra i coperchi e quindi, ima volta che siano state fatte intervenire la pressa e la macchina sigillatrice, il contatore bidirezionale conta il numero dei coperchi alimentati al pre-riscaldatore e quelli che fuoriescono dalla macchina sigillatrice? Quando questi numeri si discostano da una quantit? prestarbilita, per ??????? 4/ l'alimentazione dalla <">base della tramoggia viene interrotta e fatta ripartire dopo che siano stati alimentati alla sommit? della tramoggi a quattro coperchi? Di conseguenza il numero dei coperchi nella tramoggia non varia mai di pi? di 4? per cui la separazione fra le estremit?non cambia sigiificativamente? In the case of the pre-heater for steel lids, the transfer? Does the merit of warm air from the hot air to the lids depend to a large extent on the separation between the lids? Consequently, to ensure good temperature control? it is necessary to precisely control this separation. slightly higher than that of the press; for example ^ if the press produces 300 lids per minute, the sealing machine will come? set to produce 310 lids per minute? Does the feeding of the lids from the sealing machine foresee the presence of proximity detectors? to detect the height of the stack of covers? When the stack reaches a fixed lower limit, is the feeding of covers from the stack to the sealing station automatically delayed until the end of the stack reaches a fixed upper limit? In this way the press operates continuously but the sealing machine operates intermittently. Obviously ? possible to match the speed? of the two devices exactly? It is more? difficult to operate intermittently a press and? preferable that the sealing machine operates more? quickly of the press, instead? the opposite? When said plant is used with the pre-heater for steel lids, the number of lids in the magnetic hopper varies continuously, which in turn causes the separation between the individual lids to vary. To be able to solve this problem? was developed a <? > bidirectional electronic counter which operates in the following way; a proximity detector? reveals the lids as the lids are fed to the top of the magnetic hopper, while the other proximity detector? reveal the lids as they leave the sealing machine? The required number of lids is fed into the pre-heater to provide the necessary separation between the lids and then, once the press and sealing machine have been operated, the bidirectional counter counts the number of lids fed to the pre-heater and those that come out of the sealing machine? When do these numbers deviate from a quantity? prestarbilita, for ??????? 4 / is the feed from the bottom of the hopper interrupted and restarted after they have been fed to the top of the four-lid hopper? Consequently, the number of lids in the hopper never varies by more than 4? the separation between the extremities does not change significantly?

E* da notare che la tramoggia magietica usata con ima unit? preriscaldatrice per coperchi di acciaio non ? di per se stessa nuova? Tramojj ge magietiche sono in uso industrialmente da parecchi .anni come mezzo per ridurre il peso della pila di coperchi sul meccanismo di alimentazione di una macchina sigillatrice? Note that the magic hopper used with a unit? preheater for steel lids not? in itself new? Are magietics in use industrially for several years as a means of reducing the weight of the stack of lids on the feed mechanism of a sealing machine?

Una volta che i coperchi siano stati sigillati e siano usciti dalla macchina sigillatrice, essi vengono trasferiti lungo un inqpianto trasportatore alla stazione di imballaggio? Questo impianto trasportatore ? costituito di solito da un canale semicircolare? Se detto canale viene, usato con il processo a pre-riscaldatorep il vapor d'acqua che evapora dai coperchi caldi non pu? sfuggire e si condensa al fondo del canale, cosicch? per poter garantire una rapida evaporazione dell'acqua sul trasportatore, l'impianto trasportatore sar? tale da permettere una buona circolazione d' aria attorno ai coperchi? Si ? scoperto che il modo migliore di assicurare questa circolazione consiste nel sostituire il canale semi cilindri co con un sistema a 4 rotaie, come indicato negli annessi disegni? Once the lids have been sealed and exited the sealing machine, are they transferred along a conveyor plant to the packing station? This conveyor plant? usually consisting of a semicircular canal? If this channel is used with the pre-heater process, the water vapor that evaporates from the hot lids cannot be used. escape and condenses at the bottom of the channel, so that? in order to ensure rapid evaporation of the water on the conveyor, the conveyor system will be? such as to allow good air circulation around the lids? Yup ? discovered that the best way to ensure this circulation consists in replacing the semi-cylindrical channel with a 4-rail system, as indicated in the attached drawings?

Le normali condizioni di funzionamento del pre-riscaldatore per coperchi di acciaio si basano sul riscaldamento dei coperchi ad tuia temperatura compresa fra 60 e 120?C al momento della sigillatura? Tuttavia, l'effettiva temperatura necessaria per assicurare che i coperchi siano essiccati entro il tempo specificato dipende da parecchi fattori^quali le dimensioni del coperchio il peso del composto nel coperchio e l'ef? fettivo procedimento di imballaggio e immagazzinaggio dei coperchi adottato inun particolare impianto? Nel caso dei coperchi di alluminio ? possibile adottare temperature bassisime, generalmente comprese fra 50 <e >120?C, grazie al fatto che quando i coperchi di alluminio vengono sigillati, l?impianto trasportatore dalla macchina sigillatrice ? di solito molto lungo in quanto i coperchi vengono alimentati all?altra installazione per l'acqui-Bizione della caratteristica di apertura facilitata? The normal operating conditions of the steel lid pre-heater are based on heating the lids to a temperature between 60 and 120 ° C at the time of sealing? However, the actual temperature required to ensure that the lids are dried within the specified time depends on several factors such as the size of the lid, the weight of the compound in the lid and the ef? Is the actual lids packaging and storage process adopted in a particular facility? In the case of aluminum lids? It is possible to adopt very low temperatures, generally between 50 <and> 120 ° C, thanks to the fact that when the aluminum lids are sealed, the conveyor system from the sealing machine? usually very long as the lids are fed to the other installation for the acquisition of the easy opening feature?

L'oggetto dell'invenzione apparir? pi? chiaramente comprensibile dalla lettura del teeto della descrizione congiuntamente agli annessi disegni dove: The object of the invention will appear? pi? clearly understandable from the reading of the description together with the attached drawings where:

la figura 1 ? una vista schematica in elevazione dell'appareochiatura secondo l'invenzione; figure 1? a schematic elevation view of the apparatus according to the invention;

la figura 2 ? una vista schematica in elevazione del pre-riscaldatore per coperchi di alluminio; figure 2? a schematic elevation view of the pre-heater for aluminum lids;

la figura 3 ? una vista schematica in elevazione e laterale del pre-riscaldatore per coperchi di acciaio; figure 3? a schematic elevation and side view of the pre-heater for steel lids;

la figura 4 ? una vista simile alla figura 3 in cui compaiono i sensori di controllo della macchinar figure 4? a view similar to Figure 3 showing the machine control sensors

La figura 1 ? una vista schematica nella quale la pressa che forma i coperchi ? stata indicata con 1; 2 ? il dispositivo per il trasporto dei coperchi dalla pressa all'unit? pre-riscaldatrice, 3 ? la macchina sigillatrice; 4 ? l'unit? pre-riscaldatrice; e 5 ? un secondo dispositivo trasportatore che raccoglie i coperchi per 1'imballaggio? Figure 1? a schematic view in which the press forming the lids? was indicated with 1; 2 ? the device for transporting the covers from the press to the unit? pre-heater, 3? the sealing machine; 4? the unit? pre-heater; and 5? a second conveyor device that collects the lids for packaging?

Claims

1 Apparatus for sealing steel and / or aluminum lids of cans with a sealing compound, characterized in that it comprises: a conveyor device at room temperature for lids coming from a manufacturing press; thuja sealing machine; a unit? pre-heater installed in the machine that heats the lids arriving from the conveyor before sealing; a counter device that counts the lids fed to the pre-heater and those that come out of the sealing machine; a second conveyor device that collects the lids from the sealing machine and takes them to a packing station, where they are suitably arranged for the completion of the drying process?

2 Apparatus according to claim 1, characterized in that the unit? or pre-heater for steel lids? consisting of the magnetic hopper for lids, consisting of a tube or cylindrical chamber of stainless steel with two permanent magnets arranged to face each other and outside the chamber, and which, by means of the magnetic field created between the two, separates the co because of each other automatically so as to allow air to be blown between the lids; the lids being heated with the air, which coming from a blower? previously heated.

3 Apparatus according to claims 1 and 2, characterized in that the heating of the lids takes place laterally thanks to the fact that the blower passes air through at least one vertical opening in the cylindrical chamber of the pre-heater.

4 Apparatus according to claims 1 and 3, characterized in that the unit? pre-heater for aluminum lids comprises an insulated cylindrical chamber in which hot air is blown in at the base and exits at the top, the chamber presenting a series of bulkheads that ensure correct air circulation ?

5 Apparatus according to claims from. 1 to 4? characterized in that the bidirectional electronic counter device includes a proximity detector for the height of the stack of lids which reveals the lids as they come to the mit? magnetic pre-heater hopper and a second proximity detector which reveals the lids as they leave the sigil machine? latricej and that when the press and compound applicator machine are running, the bidirectional counter counts the number of lids fed to the pre-heater and those that leave the machine for compound application?

6. Apparatus according to the preceding claims, carat? terrified by the fact that the normal operating conditions of the pre-heater of steel lids include heating the lids to a temperature of 60-120 ° C, at the time they are sealed, while the temperature for aluminum lids oscillates between 50 and 120 ? C.

7 Apparatus for sealing steel and / or aluminum lids of cans with a sealing compound / essentially as described below. above and illustrated in the accompanying drawings

6. Process for applying a water based sealing compound to steel and / or aluminum can lids prior to? the union of said lids with said jars, characterized in that the lids are heated prior to the application of the sealing compound thereto to immediately initiate the evaporation of water from the compound;

Process according to claim 8, wherein after applying the sealing compound to the pre-heated lid, the lids are transferred along a conveyor, during which step further evaporation of the compound occurs.

The present deaeration relates to an apparatus and a pr? -. failure to seal lids, steel and / or aluminum cans with a sealing compound, suitable for use in the manufacture of cans or "cans".

Traditionally, metal cans for drinks, food and other products have been obtained from a cylindrical body on which two closing elements (generally known as can lids) are tightened, one at each end. The jar manufacturer locks one of the jar lids in place and sends the empty jars and lids to the top. of the jars to the packer. Once the jars have been filled with the product! packer tightens the other lid. In recent years so-called two-piece cans have been introduced and widely adopted. With this type of jar, the body and unp

Lids are formed as a single piece by means of a deep drawing and wall forming or drawing and re-drawing process whereby only one lid is required for the jar. In any type of jar, the jar lid provides an airtight seal to the jar body to prevent bacteria from entering or dispersing the jar contents. To obtain this hermetic seal? Do you need to coat the can lid channel with a material (generally known as a "sealing or wandering compound")? This is done by the can manufacturer during the lids manufacturing process. The material is applied to the "jar lid channel." liquid form injecting it into the channel itself, when the latter rotates at high speed? so that the centrifugal force allows an appropriate distri? bution of the sealing compound into the lid channel?

Can sealing or sealing compounds be of two types, which are conventionally known as water-based compounds and solvent-based compounds? The water-based compound consists of a dispersion of the components of the material in water, while the compound a? if the solvent consists of a solution of some of the components and a dispersion of others in an organic liquid medium, usually hexane? After the lid of the jar has been sealed with the liquid mixture? need to separate the liquid phase in order to obtain a solid joint? In the case of solvent-based compounds there? it is carried out simply by letting the hexane evaporate in ambient conditions. In the case of the water-based compounds, traditionally the sealing compound was dried by the application of heat by passing the previously sealed lids through an oven of some kind? Are two types of kilns generally used, known as tunnel kiln and vertical kiln?

The tunnel oven? consisting of a long oven heated by hot air, usually coming from a gas burner, with a conveyor belt running through the oven? Piles of lids are placed on the tank and then conveyed through the oven, usually for a residence time of 20 minutes. When they come out of the oven, are the stacks of lids separated by hand and stored in any suitable node for internal use in the factory or for shipment to the manufacturer?

The screw oven? consisting of pairs of rotating worm screws which are arranged vertically and contained within a hot air oven? The lids of the cans are fed from the sealing machine where the compound? already? been applied automatically to the worm screws, and the rotational movement of the latter conveys the covers vertically, the covers being separated by the thread pitch of the screws? The residence time in a screw oven? generally 4 minutes? The usual length of vertical screws? that necessary to give a transport time of 1 minute for each jar lid, from the bottom to the top of the screws. Therefore, ovens of this type generally have four series of screws with alternating series with right-hand and left-hand thread? Are the lids of the cans mechanically transferred from the ends of a series of screws to the beginning of the next series? At the exit from the oven, the lids are automatically fed to be stacked according to a predetermined arrangement, from where they are picked up manually for the use in the factory or for dispatch to the packer?

The tunnel type oven is mechanically very reliable, since ? simply constituted by a conveyor belt that crosses the oven itself, but it requires a large amount of manpower as the stacks of lids must be loaded manually at one end? and collected at the other end. The screw-type ovens do not require manual intervention? doper? equally large, but on the other hand are they extremely susceptible to mechanical failures mainly due to the mechanism for transferring the can lids from one set of screws to the next set? These mechanical problems represent a waste of operational time and therefore reduce? the overall efficiency of the lid manufacturing process?

In the case of the solvent-based compounds, these do not require any type of oven, as they are Are the lids automatically transferred from the labeling machine to a short conveyor system, and from the conveyor are the lids manually transferred to any form of packaging suitable for use in the factory or shipping to the packer? Most of the organic solvent evaporates while the jar lids are on the conveyor system and the small amount? what remains of it evaporates during storage.

From the description provided above will appear? evident how solvent-based compounds are the type of compound pi? suitable for use from the can manufacturer's point of view? However, is the presence of the organic solvent a problem in countries with laws regarding environmental toxicology and safety conditions in the workplace? Obviously there is hexane vapor in the atmosphere surrounding the coating machine and the permissible concentration of hexane in the air? in many countries subject to legislation? Furthermore, in many countries there are limits on the quantity? of organic vapor that can? be emitted from a facility, such as that from solvent-based paints and can sealing compounds? So many countries are moving away from solvent-based compounds? However, is there considerable resistance on the part of manufacturers regarding the conversion to furnaces for drying water-based compounds, associated with the problems mentioned above? Furthermore, even can manufacturers who generally use water-based compounds with conventional ovens would achieve substantial benefits if they could do without these supplies.

In view of these considerations,? has been developed a new type of water-based compound with a high solids content, which can? be dried without having to use an oven, while also providing a joint with all the characteristics for a satisfactory hermetic sealing of the cans? However, despite the fact that this compound can? be air dried, the time it takes to dry the joint largely depends on the ambient conditions in the can manufacturing plant, i.e. from the temperature and humidity? relative of the air, as well? from the process by which the lids of cans are packaged and stored after the sealing operation. Given this limitation, does the invention relate to a process developed to eliminate this uncertainty as regards the drying time without having to resort to a conventional oven? The present process therefore combines? the advantages of the easy handling of a solvent-based compound, with the advantages of a water-based compound in terms of toxicity. and environmental contamination?

Does the concept behind this process involve heating the lids before they are sealed so that the compound is applied * to a pre-heated lid? If the lid? sufficiently hot, part of the water present in the compound evaporates immediately upon application of the compound to the lid, and the majority of the water evaporates while the lids are transferred along the conveyor system which? similar to that used with the "solvent-based compound?" Consequently, (when the lids are removed from the conveyor system and packed for storage ^ the moisture remaining in the joint is low enough to allow the remainder to evaporate during storage within a short period of time?

Due to the fact that the lids are heated before sealing instead of? after sealing, how does the process take place in the case of conventional ovens? known as "pre-heating", and the unit? who warms the lids? known as "pre-heated? re"? Could it be concluded that there is no advantage in heating the lids prior to sealing them instead? after? However, don't you? This is the case. In the conventional process, if the drying process of the sealing compound takes place abruptly at very high temperatures over a short period of time, does the compound tend to form vesicles? There? it is due to the fact that the surface of the compound dries first, forming a curtain that prevents the evaporation of the water from the inside and therefore causes? the formation of vesicles under the cortex? Consequently there is a limit regarding the speed? drying of sealed lids in an oven, which means that there are limits to the usable temperature? Also, with conventional "water-based compounds? Do you need to make sure that the sealing compound is completely dry when the lids leave the oven? These limitations have a minimal limit on the size of the oven. * However, with the preheater unit , and since the lids are not sealed when heated there is no limit to the rate at which they can be heated, and therefore the heating can be done as quickly as necessary, so that the unit can be heated. be manufactured in a completely compact form The pre-heater unit can be installed on top of existing equipment used for sealing can lids, in place of the machine where the lids are fed into the machine which means that no additional floor space is needed, as in the case of the oven?

Depending on whether the lids are made of steel or aluminum, are two different configurations of pre-se aiders used? In both cases the lids are heated by the action of hot air on them, the hot air coming from a fan after being passed attracts towards electric resistances * In the case of steel lids and because of the low conductivity? thermal of steel? it is necessary to separate the lids so that hot air can be blown between them * Ci? is obtained by using a magic hopper? Does the magic hopper consist of a cylindrical stainless steel tube with a series of permanent magnets arranged on both sides of the tube? Does the magietic field created between the two magieties induce magietism in the steel lids, so that they repel each other and are automatically separated? The distance between the individual covers can? be adjusted by means of the separation of the magnets? Are the lids removed from the bottom of this magic hopper by the 'feed mechanism of the sealing machine and fed to the sealing stationJ while at the same time the lids are fed up by a conveyor belt which proceeds from the press that produces the lids? During the passage from the top? at the base of the magnetic hopper are the lids heated by hot air which is blown through them?

In the case of aluminum lids, is it because of their much higher conductivity? thermal compared to steel lids t not? It is necessary to separate them and, therefore, the pre-heater for aluminum lids essentially consists of an insulated cylindrical jacket into which hot air is blown sideways, which then comes out from the top. Is a series of bulkheads used inside this cylindrical chamber in order to ensure proper air circulation? In both types of pre-heater, the hot air that escapes from the pre-heater can escape. be recycled to the blower in order to improve the overall thermal efficiency of the process?

In the case of the pre-rewelding machine for steel lids, the transfer? merit of heat from the hot air to the lids depends on. large extent from the separation between the lids? Accordingly, to ensure good temperature control? need to precisely control this separation? The normal operating criterion of the sealing machine, which is automatically fed with lids from a press, consists in making the sealing machine operate at a speed? slightly higher than that of the press} for example ^ if the press produces 300 lids per minute, the sealing machine will come? set to produce 310 lids per minute? Does the feeding of the lids from the sealing machine foresee the presence of proximity detectors? to detect the height of the stack of covers * When the stack reaches a fixed lower limit, is feeding the covers from the stack to the sealing station automatically delayed until the end of the stack reaches a fixed upper limit? In this way the press operates continuously but the sealing machine operates intermittently. Obviously ? possible to match the speed? of the two devices exactly? It is more? difficult to operate intermittently a press and? preferable that the sealing machine operates more? quickly of the press, instead? the opposite? When said plant is used with the pre-heater for steel lids, the number of lids in the magnetic hopper varies continuously, which in turn causes the separation between the individual lids to vary. To be able to solve this problem? a bidirectional electronic counter has been developed which operates in the following way: a proximity detector? reveals the lids as the lids are fed to the top of the magnetic hopper, while the other proximity detector? reveal the lids as they leave the sealing machine? The required number of lids is fed into the pre-heater to provide the necessary separation between the lids and then, once the press and sealing machine have been operated, the bidirectional counter counts the number of lids fed to the pre-heater and those that come out of the sealing machine? When do these numbers deviate from a quantity? prestarfcilita, for example 4 / the feeding from the base of the hopper is interrupted and restarted after they have been fed to the top? of the four-lid hopper? Consequently, the number of lids in the hopper never varies more? of 4? so the separation between the ends does not change significantly?

Note that the magic hopper used with a unit? preheater for lids d? steel not? in itself new? Magnetic trimmings have been in industrial use for several years as a means of reducing the weight of the stack of lids on the feed mechanism of a marking machine?

Once the lids have been sealed and exited the labeling machine, are they transferred along a conveyor system to the packing station? This conveyor plant? usually consisting of a semicircular canal? If this channel is used with the pre-heater process, the water vapor evaporating from the hot lids cannot be used. escape and condenses at the bottom of the channel, so that? in order to ensure rapid evaporation of the water on the conveyor, the conveyor system will be? such as to allow good air circulation around the lids * Yes? discovered that the best way to ensure this circulation consists in replacing the semi-cylindrical channel with a 4-rail system, as indicated in the attached drawings?

Normal operating conditions of the pre-heater for steel lids are based on heating the lids to a temperature between 60 and 120 ° C at the time of sealing. However, the actual temperature required to ensure that the lids are dried within the specified ten ^ o depends on several factors ^ such as the size of the lid? the weight of the compound in the lid and the actual packaging and storage process of the lids adopted in a particular facility? In the case of aluminum lids? Is it possible to adopt low sime temperatures, generally between 50 and 120 ° C, thanks to the fact that the aluminum lids are sealed, the conveyor system from the sealing machine? usually very long when the lids are fed to the other installation for the acquisition of the facilitated opening characteristic.

Will the object of the invention appear? pi? clearly understandable from reading the text of the description together with the attached drawings where:

figure 1? a schematic elevation view of the apparatus according to the invention;

figure 2? a schematic elevation view of the pre-heater for aluminum lids;

figure 3? a schematic elevation and side view of the pre-heater for steel lids;

figure 4? a view similar to Figure 3 in which the control sensors of the machine appear

Figure 1? a schematic view in which the press forming the lids? been indicated with i; 2 ? the device for transporting the covers from the press to the unit? pre-heater, 3? the sealing machine; 4? the unit? pre-heater; and 5? a second conveyor device that collects the lids for packaging

1 ?? (^ ?? a sealing for the sealing of steel and / or aluminum lids of cans with a sealing compound, characterized by comprising: a conveyor device at room temperature for lids coming from a manufacturing press; a sealing machine; a pre-heating unit installed in the machine that heats the lids arriving from the conveyor before sealing; a counter device that counts the lids fed to the pre-reheater and those that come out of the sealing machine; a second conveyor device that collects the lids from the originating machine and takes them to a packing station / where are they suitably arranged for the completion of the drying process?

2. OPERATION according to claim 1, characterized by the fact that the unit? or pre-heater for steel lids? consisting of the magnetic hopper for lids, consisting of a tube or cylindrical chamber of stainless steel with two permanent magnets arranged to face each other and outside the chamber, and which, by means of the magnetic field created between the two, separates the co_ because of each other automatically so as to allow air to be blown between the lids; the lids being heated with the air, which coming from a blower? been previously heated.

3. PERFORMANCE According to claims 1 and 2, characteriz? zatfc in that the reheating of the lids takes place laterally due to the fact that the blower passes air through at least one vertical opening in the cylindrical chamber of the preheater.

4 "PERF EZI ONAMENT O claims 1 and 3 | characterized by the fact that the pre-heating unit for aluminum lids comprises an insulated cylindrical chamber in which hot air is blown inside at the base and exits at the base. of the top, the room presenting, a Berie of bulkheads that ensure the correct circulation of the air?

? IMPROVEMENT according to claims 1 to 4, characterized? by the fact that the bidirectional electronic counter device includes a proximity detector? for the height of the stack of lids which provides to reveal the lids as they are fed to the som? mit? of the magnetic hopper of the pre-heater, and a second detector of proximity? which detects the lids as they leave the sealing machine and that when the press and compound applicator are in operation the bidirectional counter counts the number of lids fed to the pre-heater and those that leave the machine for the application of the compound. composed*

6 {<? according to the preceding claims, characterized? from the fact that the normal operating conditions of the pre-rieca Maker of steel lids foresee the heating of the lids to a temperature of 60-1200C, at the time they are sealed, while the temperature for aluminum lids oscillates between 50 and 120 ° C ?

7. Apparatus for sealing steel and / or aluminum lids of cans with a sealing compound / essentially as described below. above and illustrated in the attached drawings *