CH376651A - Method for producing a hollow body and hollow body produced by this method - Google Patents

Method for producing a hollow body and hollow body produced by this method

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Publication number
CH376651A
CH376651A CH8233559A CH8233559A CH376651A CH 376651 A CH376651 A CH 376651A CH 8233559 A CH8233559 A CH 8233559A CH 8233559 A CH8233559 A CH 8233559A CH 376651 A CH376651 A CH 376651A
Authority
CH
Switzerland
Prior art keywords
hollow body
intermediate electrode
welding
electrode
welded
Prior art date
Application number
CH8233559A
Other languages
German (de)
Inventor
Girtanner Viktor Dr Chem
Baehni Hermann
Original Assignee
Kunststoff Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kunststoff Ag filed Critical Kunststoff Ag
Priority to CH8233559A priority Critical patent/CH376651A/en
Publication of CH376651A publication Critical patent/CH376651A/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/04—Dielectric heating, e.g. high-frequency welding, i.e. radio frequency welding of plastic materials having dielectric properties, e.g. PVC
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C27/00—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas
    • A47C27/08—Fluid mattresses or cushions
    • A47C27/081—Fluid mattresses or cushions of pneumatic type
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C27/00—Spring, stuffed or fluid mattresses or cushions specially adapted for chairs, beds or sofas
    • A47C27/08—Fluid mattresses or cushions
    • A47C27/10—Fluid mattresses or cushions with two or more independently-fillable chambers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/004—Preventing sticking together, e.g. of some areas of the parts to be joined
    • B29C66/0042—Preventing sticking together, e.g. of some areas of the parts to be joined of the joining tool and the parts to be joined
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/01—General aspects dealing with the joint area or with the area to be joined
    • B29C66/05—Particular design of joint configurations
    • B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
    • B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
    • B29C66/112—Single lapped joints
    • B29C66/1122—Single lap to lap joints, i.e. overlap joints
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B29C66/432—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B29C66/432—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms
    • B29C66/4322—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms by joining a single sheet to itself
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/49—Internally supporting the, e.g. tubular, article during joining
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/73—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset
    • B29C66/739—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset
    • B29C66/7392—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of at least one of the parts being a thermoplastic
    • B29C66/73921—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the intensive physical properties of the material of the parts to be joined, by the optical properties of the material of the parts to be joined, by the extensive physical properties of the parts to be joined, by the state of the material of the parts to be joined or by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of the parts to be joined being a thermoplastic or a thermoset characterised by the material of at least one of the parts being a thermoplastic characterised by the materials of both parts being thermoplastics
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/71—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the composition of the plastics material of the parts to be joined
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/83—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools
    • B29C66/832—Reciprocating joining or pressing tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
    • B29K2027/06—PVC, i.e. polyvinylchloride
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2022/00—Hollow articles
    • B29L2022/02—Inflatable articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/751—Mattresses, cushions

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Resistance Welding (AREA)

Description

       

  



  Verfahren zur Herstellung eines Hohlkörpers und nach diesem Verfahren hergestellter Hohlkörper
Hohlkörper, wie Bälle, Kissen, Matratzen, Schwimmtiere, Flüssigkeitsbehälter, Schläuche usw., werden üblicherweise aus thermoplastischer Folie, insbesondere aus Folie aus   weichgemachtem    Polyvinylchlorid (PVC) oder PVC-Mischpolymerisaten oder aus mit thermoplastischem Material   beschichte-    tem Gewebe durch Verschweissen der Nahtstellen im   Hochfrequenzfeld    hergestellt.



   Bei Druckbeanspruchung eines solchen Hohlkörpers, z. B. durch Aufblasen mit Luft oder durch Füllen mit Flüssigkeit wird die Schweissnaht auf Kerbwirkung beansprucht und reisst leicht auf. Aus der Praxis ist es bekannt, dass z. B. Matratzen aus Weich-PVC-Folie sehr häufig zu Reklamationen Anlass geben, weil die Schweissnähte aufplatzen.



  Dabei wären solche Matratzen wegen der Unempfindlichkeit gegenüber Licht und Wasser besonders als Schwimmatratzen sehr gesucht und den bisher verwendeten Matratzen aus gummierten Stoffen wegen deren Anfälligkeit gegen Sonne, Wasser und Alterung weit überlegen. Bis jetzt konnten sich aber z. B.   Schwimmatratzen    aus Thermoplastmaterial wegen den unzuverlässigen Schweissnähten nicht durchsetzen. Die Erfindung betrifft ein Verfahren zur Herstellung eines Hohlkörpers durch   Verschwei-      ssen    einer Folie aus thermoplastischem Kunststoff oder von mit solchem Kunststoff beschichtetem Gewebe, welches Verfahren dadurch gekennzeichnet ist, dass die Schweissnaht unter Zuhilfenahme einer Zwischenelektrode durch Überlappung hergestellt wird.



   In der Zeichnung sind Ausführungsbeispiele dargestellt.



   Fig.   1    zeigt eine Elektrodenanordnung, wie sie bei der Durchführung des Verfahrens verwendet werden kann. Aus der PVC-Folie   A    wird durch Umbiegen und   Uberlappen    der Seitenränder ein Schlauch gebildet. Dieser Schlauch wird zwischen die   Elektro-    den E und F gelegt. In den Schlauch wird unter die zu bildende   SchweS3naht    die Zwischenelektrode Z eingeführt. Unter Wirkung des   Hochfrequenzfeldes    wird zwischen der Elektrode E und der Zwischenelektrode Z eine Schweissnaht gebildet.



   Die   Zwischenelektrode    hat zweckmässig eine   GTunldfläche bz¯ 1, 1 bE, wobei bE    die Grundfläche der einen Aussenelektrode E bedeutet. Dadurch ist die der Schweissnaht gegenüberliegende Folie am Schweissprozess nicht   mitbeteiligt,    und die Schweissstelle wird nicht   durchmarkiert.   



   Fig. 2 zeigt einen Querschnitt durch einen   erfin-      dungsgemäss hergestellten    Schlauch. Wird dieser aufgeblasen, ist die Naht in Richtung der Pfeile auf Scherwirkung beansprucht. Eine solche Naht kann bei den praktisch auftretenden Beanspruchungen nicht aufreissen.



   Versuche an einer 0,4 mm starken,   weichgemach-    ten   Polyvinylchloridfolie    von der Zusammensetzung : 100 Teile PVC, 50 Teile Dioctylphthalat, 2 Teile Stabilisator haben folgende Festigkeiten   der Schweiss-      naht engeben.   



   Nach üblichen Verfahren Erfindungsgemäss geschweisst geschweisst
Zerreisskraft Zerreisskraft    I    cm breiter Streifen   1    cm breiter Streifen Versuch 1 5,2 kg Versuch 5 8,0 kg* Versuch 2 5,0 kg Versuch 6 8,4 kg* Versuch 3 4,8 kg Versuch 7 9,0 kg* Versuch 4 5,1 kg Versuch 8 9,4 kg* Versuch 5 4,8 kg Versuch 9 8,0 kg Mittel 5,0   kg Mittel    8,4 kg   *    Folie zerrissen, Schweissnaht intakt. 



   Eine nach dem neuen Verfahren hergestellte Schweissnaht weist deshalb   eine etwa 70 /o höhere    Festigkeit auf als eine gewöhnliche Schweissnaht, wobei in den meisten Fällen beim Zerreissversuch die Schweissnaht intakt bleibt und die Folie selbst reisst. Bei der herkömmlichen Schweissmethode ist in jedem Fall die Schweissnaht die   schwächste Stelle.   



   Der Fortschritt dieser Schweissnaht ist   eklatant    und ermöglicht erstmals die Herstellung von stark beanspruchten Hohlkörpern, wie Schläuche, Matratzen, Behälter, ohne dass ein Aufreissen der   Schweiss-    naht befürchtet werden muss.



   Die   Zwischcnelektrodekami    wie in Fig. 3 und 4 veranschaulicht ausgebildet sein, wobei die Grundfläche wiederum   zweckmässig bz  >  1, l bE beträgt.   



   Die   Zwischenelektrode    kann auch aus einer Metallfolie bestehen (Fig. 5), wobei ihre Höhe   hz      zweck-    mässig mindestens   0,    01 mm betragen soll. Als Metall kann z. B. Kupfer,   Messin,    Aluminium verwendet werden.



   Weiterhin kann die   Zwischenelektrode    auch aus einem starren oder flexiblen Isoliermaterial   1    (z. B.



     Phenolharz, phenolharzgetränkte    Papiere, Karton, Thermoplastfolie mit hohem Erweichungspunkt) bestehen, welches ein-oder zweiseitig mit einem Metalllack L beschichtet ist.



   Alle offenen Hohlkörper können nach diesem Verfahren mit stabilen   Zwischenolektroden    geschweisst werden. Geschlossene e Hohlkörper können entweder so geschweisst werden, dass als Zwischenelektrode ein   Metallfolienband    (Fig. 5) oder ein flexibles metallackbeschichtetes Isoliermaterialband (gemäss Fig. 6) verwendet wird, welches nach der Schweissung im Hohlkörper verbleibt. Oder es wird mit stabiler   Zwischenelektrode    so weit geschweisst, bis noch eine so grosse Öffnung verbleibt, dass die Zwi  schenelektrode    gerade noch herausgenommen werden kann. Die verbleibende Offnung wird hierauf mit Hilfe einer Metallfolie oder eines   metallackbeschich-      teten    Isoliermaterials zugeschweisst.



   Beispiel
Eine Matratze mit Zwischenstegen (gemäss Fig. 7) kann wie folgt hergestellt werden :
Um eine Scherbeanspruchung in den Schweissnähten zu erzielen, müssen die Zwischenstege 1 und 2 auf jeder Seite auf die Grund-und Deckfolie aufgeschweisst werden. Dabei können die Zwischenstege aus zwei separaten Folien bestehen (Fig. 8) oder aus einem einzigen   Doppel-T-Profil      (Fig.    9).



   Der Mittelsteg   1    wird nach bekannter Methode in ein, zwei oder vier Arbeitsgängen eingeschweisst.



   Der Steg 2 kann nun so geschweisst werden,   dal3    für die innere Seite eine bei a und   b      teilbare      Zwischenelektrode verwendet    wird (Fig. 10), so dass der ganze Steg 2 bis auf zwei Offnungen bei a und   b    von je 8 cm Länge in einem Schweissvorgang zwischen zwei Elektroden verschweisst wird. Die Zwi  schenelektrode    wird hierauf getrennt und die zwei Hälften nacheinander durch die Öffnungen a und b gestossen und durch Drehen aus den Kammern entfernt. Hierauf werden die Öffnungen a und b durch Einlage einer   0,    08 mm dicken, 3 cm breiten und 12 cm langen Aluminiumfolie mittels einer 10 cm langen   Stabelektrode    zugeschweisst.

   Gleichzeitig mit der innern Seite wird mit einer   gleichgeformten    Elektrode (Fig. 10) auch die äussere Naht des Steges 2 verschweisst, ebenfalls mit Auslassung von Öffnungen bei a und b, welche nach Entfernung der innern   Zwischenelektrode    zugeschweisst werden.



   Die Ventile   V,    V können nun auf   iibliche    Weise oder aber erst nach Fertigstellung der Matratze mittels einer   Metallfolienzwischenelektrode    einge  schweisst    werden.



   Die Schweissnaht 3 wird nun entweder unter Zuhilfenahme eines Aluminiumfolienstreifens in einem Arbeitsgang verschweisst oder aber mit einer teilbaren, stabilen   Zwischenelektrode,    welche wie bei Fig. 10 zwei Öffnungen frei lässt, welch letztere nach Entfernen der stabilen   Zwischenelektrode    mittels eines   Aluminiumfolienstreifens zugeschweisst werden.  



  



  Method for producing a hollow body and hollow body produced by this method
Hollow bodies, such as balls, pillows, mattresses, swimming animals, liquid containers, hoses, etc., are usually made of thermoplastic film, in particular film made of plasticized polyvinyl chloride (PVC) or PVC copolymers or from fabric coated with thermoplastic material by welding the seams in the High frequency field established.



   When such a hollow body is subjected to pressure, e.g. B. by inflating with air or by filling with liquid, the weld seam is stressed to notch effect and tears easily. From practice it is known that, for. B. mattresses made of soft PVC film very often give rise to complaints because the weld seams burst.



  Because of their insensitivity to light and water, such mattresses would be in great demand, especially as swimming mattresses, and would be far superior to the mattresses made of rubberized materials previously used because of their susceptibility to sun, water and aging. Until now, however, z. B. not enforce floating mattresses made of thermoplastic material because of the unreliable weld seams. The invention relates to a method for producing a hollow body by welding a film made of thermoplastic or fabric coated with such a plastic, which method is characterized in that the welding seam is produced by overlapping with the aid of an intermediate electrode.



   Exemplary embodiments are shown in the drawing.



   1 shows an electrode arrangement as can be used when carrying out the method. A tube is formed from the PVC film A by bending and overlapping the side edges. This hose is placed between electrodes E and F. The intermediate electrode Z is inserted into the hose under the weld seam to be formed. Under the effect of the high frequency field, a weld seam is formed between the electrode E and the intermediate electrode Z.



   The intermediate electrode expediently has a GTunldfläche bz¯ 1, 1 bE, where bE means the base area of one outer electrode E. As a result, the film opposite the weld seam is not involved in the welding process, and the welding point is not marked through.



   2 shows a cross section through a hose produced according to the invention. If this is inflated, the seam is subjected to shear in the direction of the arrows. Such a seam cannot tear open under the practical stresses that occur.



   Tests on a 0.4 mm thick, plasticized polyvinyl chloride film with the composition: 100 parts of PVC, 50 parts of dioctyl phthalate, 2 parts of stabilizer gave the weld seam strengths as follows.



   Welded according to the invention using conventional methods
Tear force Tear force I cm wide strip 1 cm wide strip Experiment 1 5.2 kg Experiment 5 8.0 kg * Experiment 2 5.0 kg Experiment 6 8.4 kg * Experiment 3 4.8 kg Experiment 7 9.0 kg * Experiment 4 5.1 kg trial 8 9.4 kg * trial 5 4.8 kg trial 9 8.0 kg average 5.0 kg average 8.4 kg * foil torn, weld seam intact.



   A weld seam produced according to the new process therefore has a strength that is around 70% higher than a normal weld seam, whereby in most cases the weld seam remains intact and the film itself tears during the tear attempt. With the conventional welding method, the weld seam is always the weakest point.



   The progress of this weld seam is striking and for the first time enables the manufacture of heavily stressed hollow bodies, such as hoses, mattresses and containers, without fear of the weld seam tearing open.



   The intermediate electrode chambers can be designed as illustrated in FIGS. 3 and 4, the base area in turn being expediently bz> 1, l bE.



   The intermediate electrode can also consist of a metal foil (FIG. 5), whereby its height hz should expediently be at least 0.01 mm. The metal can be, for. B. copper, brass, aluminum can be used.



   Furthermore, the intermediate electrode can also be made of a rigid or flexible insulating material 1 (e.g.



     Phenolic resin, paper impregnated with phenolic resin, cardboard, thermoplastic film with a high softening point), which is coated on one or both sides with a metal lacquer L.



   All open hollow bodies can be welded with stable intermediate electrodes using this process. Closed hollow bodies can either be welded in such a way that a metal foil tape (FIG. 5) or a flexible metal lacquer-coated insulating material tape (according to FIG. 6) is used as the intermediate electrode, which remains in the hollow body after welding. Or it is welded with a stable intermediate electrode until there is still an opening large enough for the intermediate electrode to just be removed. The remaining opening is then welded shut with the aid of a metal foil or an insulating material coated with a metal lacquer.



   example
A mattress with dividers (according to Fig. 7) can be produced as follows:
In order to achieve a shear stress in the weld seams, the intermediate webs 1 and 2 must be welded onto the base and cover foil on each side. The intermediate webs can consist of two separate foils (Fig. 8) or a single double-T profile (Fig. 9).



   The central web 1 is welded in using a known method in one, two or four operations.



   The web 2 can now be welded in such a way that an intermediate electrode that can be divided at a and b is used for the inner side (Fig. 10), so that the entire web 2 except for two openings at a and b, each 8 cm long in one Welding process is welded between two electrodes. The intermediate electrode is then separated and the two halves pushed one after the other through the openings a and b and removed from the chambers by turning. The openings a and b are then welded shut by inserting a 0.08 mm thick, 3 cm wide and 12 cm long aluminum foil using a 10 cm long stick electrode.

   Simultaneously with the inner side, the outer seam of the web 2 is also welded with an identically shaped electrode (FIG. 10), likewise with the omission of openings at a and b, which are welded shut after the inner intermediate electrode has been removed.



   The valves V, V can now be welded in the usual way or only after the mattress has been completed by means of an intermediate metal foil electrode.



   The weld seam 3 is now either welded with the aid of an aluminum foil strip in one operation or with a divisible, stable intermediate electrode which, as in FIG. 10, leaves two openings free, the latter being welded shut by means of an aluminum foil strip after the stable intermediate electrode has been removed.

Claims (1)

PATENTANSPRÜCHE I. Verfahren zur Herstellung eines Hohlkörpers durch Verschweissen einer Folie aus thermoplastischem Kunststoff oder von mit solchem Kunststoff beschichtetem Gewebe, dadurch gekennzeichnet, dass die Schweissnaht unter Zuhilfenahme einer Zwischenelektrode überlappt hergestellt wird. PATENT CLAIMS I. A method for producing a hollow body by welding a film made of thermoplastic material or fabric coated with such a material, characterized in that the weld seam is produced in an overlapping manner with the aid of an intermediate electrode. IL Hohlkörper, hergestellt nach Patentanspruch I, dadurch gekennzeichnet, dass er die zum Schweissen verwendete Zwischenelektrode enthält. IL hollow body, produced according to claim 1, characterized in that it contains the intermediate electrode used for welding. UNTERANSPRÜCHE 1. Verfahren nach Patentanspruch I, dadurch gekennzeichnet, dass man eine Zwischenelektrode verwendet, deren Grundfläche mindestens 1,1 mal die Fläche einer Aussenelektrode und deren Höhe mindestens 0, 01 mm beträgt. SUBCLAIMS 1. The method according to claim I, characterized in that an intermediate electrode is used whose base area is at least 1.1 times the area of an outer electrode and whose height is at least 0.01 mm. 2. Verfahren nach Patentanspruch I, dadurch gekennzeichnet, dass man als Zwischenelektrode eine Metallfolie verwendet. 2. The method according to claim I, characterized in that a metal foil is used as the intermediate electrode. 3. Verfahren nach Patentanspruch I, dadurch gekennzeichnet, dass man als Zwischenelektrode eine mit Metall beschichtete Folie aus Isoliermaterial verwendet. 3. The method according to claim I, characterized in that a metal-coated film made of insulating material is used as the intermediate electrode. 4. Verfahren nach Patentanspruch I, dadurch gekennzeichnet, dass man die Zwischenelektrode nach Beendigung des Schweissens im Hohlkörper belässt. 4. The method according to claim I, characterized in that the intermediate electrode is left in the hollow body after the welding has ended.
CH8233559A 1959-12-24 1959-12-24 Method for producing a hollow body and hollow body produced by this method CH376651A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2674074B1 (en) 2012-03-02 2020-02-12 Intex Marketing Ltd. Inflatable product with an internal tensioning structure
US11421434B2 (en) 2013-07-18 2022-08-23 Intex Marketing Ltd. Inflatable spa

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2674074B1 (en) 2012-03-02 2020-02-12 Intex Marketing Ltd. Inflatable product with an internal tensioning structure
US11421434B2 (en) 2013-07-18 2022-08-23 Intex Marketing Ltd. Inflatable spa

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