DE2549475C3 - Method and device for connecting molded bodies made of polytetrafluoroethylene - Google Patents

Method and device for connecting molded bodies made of polytetrafluoroethylene

Info

Publication number
DE2549475C3
DE2549475C3 DE2549475A DE2549475A DE2549475C3 DE 2549475 C3 DE2549475 C3 DE 2549475C3 DE 2549475 A DE2549475 A DE 2549475A DE 2549475 A DE2549475 A DE 2549475A DE 2549475 C3 DE2549475 C3 DE 2549475C3
Authority
DE
Germany
Prior art keywords
heated
polytetrafluoroethylene
ptfe
strip
temperature
Prior art date
Legal status (The legal status 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 status listed.)
Expired
Application number
DE2549475A
Other languages
German (de)
Other versions
DE2549475A1 (en
DE2549475B2 (en
Inventor
Guenter 6230 Frankfurt Freitag
Alfred Dr.-Ing. 6236 Eschborn Krahl
Gerhard Dipl.-Ing. 6080 Gross- Gerau Ullmann
Guenter 6233 Kelkheim Wenzel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sigri GmbH
Original Assignee
Sigri Elektrograhit GmbH
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 Sigri Elektrograhit GmbH filed Critical Sigri Elektrograhit GmbH
Priority to DE2549475A priority Critical patent/DE2549475C3/en
Priority to IT29034/76A priority patent/IT1063650B/en
Priority to GB45932/76A priority patent/GB1570686A/en
Priority to JP51131799A priority patent/JPS5263275A/en
Priority to FR7633413A priority patent/FR2330518A1/en
Publication of DE2549475A1 publication Critical patent/DE2549475A1/en
Publication of DE2549475B2 publication Critical patent/DE2549475B2/en
Priority to US05/867,533 priority patent/US4197149A/en
Application granted granted Critical
Publication of DE2549475C3 publication Critical patent/DE2549475C3/en
Expired legal-status Critical Current

Links

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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/82—Pressure application arrangements, e.g. transmission or actuating mechanisms for joining tools or clamps
    • B29C66/826—Pressure application arrangements, e.g. transmission or actuating mechanisms for joining tools or clamps without using a separate pressure application tool, e.g. the own weight of the parts to be joined
    • B29C66/8264—Pressure application arrangements, e.g. transmission or actuating mechanisms for joining tools or clamps without using a separate pressure application tool, e.g. the own weight of the parts to be joined using the thermal expansion 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
    • 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
    • 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
    • B29C65/14—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation
    • B29C65/1429—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface
    • B29C65/1445—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface heating both sides of the joint
    • 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
    • B29C65/14—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation
    • B29C65/1429—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface
    • B29C65/1464—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface making use of several radiators
    • B29C65/1467—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using wave energy, i.e. electromagnetic radiation, or particle radiation characterised by the way of heating the interface making use of several radiators at the same time, i.e. simultaneous welding
    • 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
    • B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
    • B29C65/50—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding using adhesive tape, e.g. thermoplastic tape; using threads or the like
    • B29C65/5057—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding using adhesive tape, e.g. thermoplastic tape; using threads or the like positioned between the surfaces 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
    • B29C66/02—Preparation of the material, in the area to be joined, prior to joining or welding
    • B29C66/022—Mechanical pre-treatments, e.g. reshaping
    • 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
    • B29C66/03—After-treatments in the joint area
    • B29C66/032—Mechanical after-treatments
    • 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
    • B29C66/114—Single butt joints
    • B29C66/1142—Single butt to butt 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
    • B29C66/01—General aspects dealing with the joint area or with the area to be joined
    • B29C66/348—Avoiding melting or weakening of the zone directly next to the joint area, e.g. by cooling
    • 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
    • B29C66/70—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
    • B29C66/81—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps
    • B29C66/818—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps ; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps
    • B29C66/8181—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps ; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps characterised by the cooling constructional aspects
    • B29C66/81815—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps ; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps characterised by the cooling constructional aspects of the clamps
    • 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
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
    • B29C66/914—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux
    • B29C66/9141—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the temperature
    • B29C66/91411—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the temperature of the parts to be joined, e.g. the joining process taking the temperature of the parts to be joined into account
    • 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
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
    • B29C66/914—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux
    • B29C66/9141—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the temperature
    • B29C66/91431—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the temperature the temperature being kept constant over time
    • 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
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
    • B29C66/914—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux
    • B29C66/9161—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the heat or the thermal flux, i.e. the heat flux
    • 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
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
    • B29C66/919—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux characterised by specific temperature, heat or thermal flux values or ranges
    • 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
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
    • B29C66/919—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux characterised by specific temperature, heat or thermal flux values or ranges
    • B29C66/9192—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux characterised by specific temperature, heat or thermal flux values or ranges in explicit relation to another variable, e.g. temperature diagrams
    • B29C66/91921—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux characterised by specific temperature, heat or thermal flux values or ranges in explicit relation to another variable, e.g. temperature diagrams in explicit relation to another temperature, e.g. to the softening temperature or softening point, to the thermal degradation temperature or to the ambient temperature
    • B29C66/91931—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux characterised by specific temperature, heat or thermal flux values or ranges in explicit relation to another variable, e.g. temperature diagrams in explicit relation to another temperature, e.g. to the softening temperature or softening point, to the thermal degradation temperature or to the ambient temperature in explicit relation to the fusion temperature or melting point of the material of one of the parts to be joined
    • B29C66/91933—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux characterised by specific temperature, heat or thermal flux values or ranges in explicit relation to another variable, e.g. temperature diagrams in explicit relation to another temperature, e.g. to the softening temperature or softening point, to the thermal degradation temperature or to the ambient temperature in explicit relation to the fusion temperature or melting point of the material of one of the parts to be joined higher than said fusion temperature
    • 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
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/92—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools
    • B29C66/924—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools by controlling or regulating the pressure, the force, the mechanical power or the displacement of the joining tools
    • B29C66/9241—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools by controlling or regulating the pressure, the force, the mechanical power or the displacement of the joining tools by controlling or regulating the pressure, the force or the mechanical power
    • 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
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/92—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools
    • B29C66/929—Measuring or controlling the joining process by measuring or controlling the pressure, the force, the mechanical power or the displacement of the joining tools characterized by specific pressure, force, mechanical power or displacement values or ranges
    • 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
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/94—Measuring or controlling the joining process by measuring or controlling the time
    • B29C66/949—Measuring or controlling the joining process by measuring or controlling the time characterised by specific time values or ranges
    • 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
    • B29C53/00—Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor
    • B29C53/36—Bending and joining, e.g. for making hollow 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
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
    • B29C65/4805—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding characterised by the type of adhesives
    • B29C65/481—Non-reactive adhesives, e.g. physically hardening adhesives
    • B29C65/4815—Hot melt adhesives, e.g. thermoplastic adhesives
    • 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
    • B29C66/02—Preparation of the material, in the area to be joined, prior to joining or welding
    • B29C66/022—Mechanical pre-treatments, e.g. reshaping
    • B29C66/0224—Mechanical pre-treatments, e.g. reshaping with removal of material
    • B29C66/02241—Cutting, e.g. by using waterjets, or sawing
    • 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
    • B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
    • 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
    • B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
    • B29K2027/18—PTFE, i.e. polytetrafluorethene, e.g. ePTFE, i.e. expanded polytetrafluorethene
    • 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
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0037—Other properties
    • B29K2995/0065—Permeability to gases
    • B29K2995/0067—Permeability to gases non-permeable
    • 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
    • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0037—Other properties
    • B29K2995/0068—Permeability to liquids; Adsorption
    • B29K2995/0069—Permeability to liquids; Adsorption non-permeable
    • 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
    • B29L2023/00—Tubular articles
    • B29L2023/22—Tubes or pipes, i.e. rigid

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Health & Medical Sciences (AREA)
  • Electromagnetism (AREA)
  • Toxicology (AREA)
  • Plasma & Fusion (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Description

Die Erfindung betrifft ein Verfahren und eine Vorrichtung zum Verbinden von Formkörpern aus gesintertem Polyfluoräthylen im Stumpfstoß, nach welchem die aneinandergepreßten Stoßflächen auf eine Temperatur oberhalb von 327° C erhitzt werden.The invention relates to a method and a device for connecting molded bodies from sintered polyfluoroethylene in the butt joint, after which the butt surfaces pressed together on a Temperature above 327 ° C are heated.

Aus Polytetrafluoräthylen (PTFE) bestehende und vorwiegend PTFE enthaltende Formteile werden wegen ihrer hervorragenden thermischen und chemischen Stabilität in zunehmendem Maße als korrosionsbeständige Auskleidung, z. B. für Chemieapparate, wie Wärmeaustauscher, Kolonnen und Behälter, verwendet. Dabei ist es — besonders für Apparate mit größerem Innendurchmesser — notwendig, Formteile, z. B. Platten oder Folien, gas- und flüssigkeitsdicht miteinander zu verbinden, da die Herstellung von PTFE-Rohren größeren Durchmessers durch Ram- oder Pastenextrusion nicht möglich ist. Weitere Beschränkungen entstehen dadurch, daß für jeden Durchmesser ein eigenes Pressenmundstück erforderlich ist und das Verhältnis Wanddicke/Durchmesser nur beschränkt variiert werden katin.Molded parts made of polytetrafluoroethylene (PTFE) and mainly containing PTFE are made Because of their excellent thermal and chemical stability, they are increasingly resistant to corrosion Lining, e.g. B. for chemical apparatus, such as heat exchangers, columns and containers used. It is - especially for apparatus with a larger inner diameter - necessary to make molded parts such. B. Plates or to connect foils to one another in a gas- and liquid-tight manner, since the manufacture of PTFE pipes larger diameter by ram or paste extrusion is not possible. Further restrictions arise from the fact that a separate press mouthpiece is required for each diameter and that The wall thickness / diameter ratio can only be varied to a limited extent.

Wegen der schlechten Benetzbarkeit des Polytetrafluoräthylens und der vergleichsweise geringen thermischen und chemischen Beständigkeit von Klebstoffen ist es bisher auch nicht gelungen, geklebte Verbindungen in einer etwa für Chemieapparate notwendigen Qualität, insbesondere mit einer hohen thermischen und chemischen Beständigkeit, herzustellen. Auch nach vorherigem Ätzen der zu verbindenden PTFE-Flächen reicht die Qualität der Verbindung für den genannten Verwendungszweck nicht aus. Die zum Verbinden von herkömmlichen thermoplastischen Kunststoffen gebräuchlichen Schweißverfahren, nach denen aneinandergepreßte Teile über den Schmelz- bzw. Erweichungspunkt des Kunststoffes erhitzt werden, sind für Polytetrafluoräthylen nicht brauchbar. Nach diesem Verfahren sind jedoch zwischen dünnen PTFE-Folien Verbindungen mit Oberlappstoß hergestellt worden, die sich für Behälterauskleidungen wegen der Materialverdickung an der Überlappung weniger gut eignen. Besonders bei Verwendung von dickeren Foliea oder Platten ist die Abdichtung derartiger Nähte, beispielsweise an Flanschbördeln, schwierig und aufwendig. Zur Herstellung von Dichtungsringen ist es schließlich nach der österreichischen Patentschrift 2 20 440 bekannt, Bandstreifen aus Polytetrafluoräthylen durch gemeinsanie Einwirkung von Hitze und Druck stumpf aneinander zu schweißen, wobei die Schweißtemperatur etwa 3700C und der Druck etwa 20 N/cm2 betragen. Das Verfahren eignet sich jedoch nur zum Verbinden von Folien verhältnismäßig geringer Dicke, etwa von 0,4 mm. Verbindungen zwischen dickeren PTFE-Folien ohne Überlappungen werden nach der französischen Offenlegungsschrift 21 63 420 dadurch hergestellt, daß V-förmige Nahtfugen zwischen zwei auf einer Unterlage fixierten PTFE-Platten mit einem PTFE-Pulver gefüllt werden und das Pulver durch stempeiförmig ausgebildete, auf den Stoß gepreßte Heizelemente erhitzt wird. Eine streichende und reproduzierbare Schweißgüte, die u. a. in komplizierter Weise von der Pulverqualität und -körnung sowie von der Packungsdichte abhängt, ist nach diesem Verfahren nur bei sorgfältiger, unter normalen Betriebsbedingungen kaum möglicher Beachtung sämtlicher Einflußgrößen zu erreichen. Nachteilig für die Schweißgüte ist schließlich die durch die Anordnung der Unterlage unterhalb derBecause of the poor wettability of polytetrafluoroethylene and the comparatively low thermal and chemical resistance of adhesives, it has so far not been possible to produce bonded connections in the quality necessary for chemical apparatus, in particular with high thermal and chemical resistance. Even after the PTFE surfaces to be connected have been etched beforehand, the quality of the connection is not sufficient for the stated purpose. The welding processes customary for joining conventional thermoplastics, according to which parts pressed together are heated above the melting or softening point of the plastic, cannot be used for polytetrafluoroethylene. According to this method, however, connections with a top lap joint have been produced between thin PTFE foils, which are less suitable for container linings because of the thickening of the material at the overlap. The sealing of such seams, for example on flange flanges, is difficult and expensive, especially when using thicker films or plates. For the production of sealing rings it is finally known according to Austrian patent specification 2 20 440 to butt-weld strips of polytetrafluoroethylene by the joint action of heat and pressure, the welding temperature being about 370 ° C. and the pressure about 20 N / cm 2 . However, the method is only suitable for joining foils of a relatively small thickness, for example 0.4 mm. Connections between thicker PTFE foils without overlaps are made according to the French laid-open specification 21 63 420 in that V-shaped seams between two PTFE sheets fixed on a base are filled with a PTFE powder and the powder is applied to the butt by means of a star-shaped design pressed heating elements is heated. A smooth and reproducible welding quality, which depends in a complicated way on the powder quality and grain size as well as the packing density, can only be achieved with this method if all influencing variables are carefully considered, which is hardly possible under normal operating conditions. Finally, the disadvantage for the welding quality is that due to the arrangement of the base below the

JS Schweißnaht bedingte unsymmetrische Temperaturverteilung im SchweißgutJS weld seam caused asymmetrical temperature distribution in the weld metal

Es ist eine Aufgabe der Erfindung, ein für Formkörper beliebiger Dicke und Größe geeignetes Verfahren zum Herstellen einer Verbindung im Stumpfstoß mit hoher Schweißgüte zu schaffen. Eine weitere Aufgabe der Erfindung betrifft die Schaffung einer Vorrichtung zur Durchführung des Verbindungsverfahrens.It is an object of the invention to provide a method suitable for moldings of any thickness and size Establishing a connection in the butt joint with high welding quality. Another task of the The invention relates to the creation of a device for carrying out the connection method.

Zur Lösung der Aufgabe wird erfindungsgemäß ein Verfahren der eingangs genannten Art vorgeschlagen, nach welchem die zu verbindenden Formkörper bis auf einen schmalen, die Stoßflächen einschließenden Streifen zwischen gekühlten Spannbacken eingespannt werden, der Streifen durch Strahlung und/oder konvektiv berührungslos erhitzt wird, beim Zusammenpressen der Stoßflächen eine Nahtverdickung erzeugt wird und die Verdickung anschließend abgearbeitet wird.To achieve the object, a method of the type mentioned is proposed according to the invention, according to which the shaped bodies to be connected except for a narrow strip enclosing the abutting surfaces be clamped between cooled jaws, the strip by radiation and / or convection is heated without contact, a seam thickening is generated when the abutting surfaces are pressed together and the thickening is then worked off.

Zur Erzeugung einer hochwertigen Verbindung ist es nach den der Erfindung zugrunde liegenden Erkenntnissen erforderlich, die Stoßflächen unter Druck auf eine Temperatur oberhalb des Kristallitschmelzpunktes von PTFE zu erhitzen und Temperatur und Druck bis zur Ausbildung einer Nahtverdickung auf die Verbindungsflächen einwirken zu lassen. Es ist weiterhin erforderlich, die Temperaturverteilung in dem erhitzten PTFE-Streifen zwischen den Spannbacken derart zu bernessen, daß ein Ausknieken des frei überstehenden PTFE-Streifens als auch zu breite oder zu schmale Aufschmelzzonen vermieden werden oder mit anderen Worten, daß unabhängig von den jeweiligen geometrisehen Formen und Maßen der zu verbindenden Körper eine Aufschmelzzone gerade ausreichender Breite erzeugt und während der Dauer des Schweißvorgangs aufrechterhalten wird. Nach der Erfindung ist esIn order to produce a high-quality connection, it is according to the knowledge on which the invention is based required, the abutment surfaces under pressure to a temperature above the crystallite melting point of To heat PTFE and to allow temperature and pressure to act on the connecting surfaces until a seam thickening is formed. It is still necessary the temperature distribution in the heated PTFE strip between the clamping jaws increases Bernessen that a kneeling of the freely protruding PTFE strip as well as too wide or too narrow Melting zones are avoided or, in other words, that are independent of the respective geometries Shapes and dimensions of the bodies to be connected a melting zone of just sufficient width is generated and maintained for the duration of the welding process. According to the invention it is

schließlich erforderlich, zur Entfernung von schädlichen Oberflächenkerben die Nahtverdickung etwa durch Hobeln oder Abziehen abzuarbeiten. Die Wirkung des erfindungsgemäßen Verfahrens ist insoweit überraschend, als das im Bereich der Stoßflächen aufgeschmolzene PTFE trotz der zur Herstellung einer hochwertigen Verbindung notwendigen und angewendeten verhältnismäßig hohen Drücke und langen Einwirkungszeitrn nicht abtropft oder ausfließt Die unerwartete mechanische Stabilität der Schmelze ist ebenfalls die Grundlage für eine einfache und sehr flexible Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens.finally necessary to remove damaging surface notches through the thickening of the seam Planing or peeling off. The effect of the method according to the invention is surprising to the extent that than the PTFE melted in the area of the abutment surfaces, despite the need to produce a high-quality connection necessary and applied relatively high pressures and long Exposure time does not drip or flow out. The unexpected mechanical stability of the melt is also the basis for a simple and very flexible device for carrying out the invention Procedure.

Besonders zweckmäßig werden die Stoßflächen auf eine Temperatur zwischen 340 und 4300C erhitzt Unterhalb dieses Temperaturbereichs sind die notwendigen Schweißzeiten verhältnismäßig lang, während oberhalb des Breichs zwar sehr kurze Schweißzeiten erzielt werden können, andererseits aber die Möglichkeit einer partiellen Zersetzung des Polytetrafluoräthylens wächst. Anpreßdruck und SchwenSzeiten betragen vorzugsweise 30 bis 150 N/cm2 bzw. 10 bis 520 min, wobei die Parameter Temperatur, Druck und Zeit bis zu einem gewissen Grade gleichartig wirken, so daß ein niedriger Wert des einen Parameters durch Erhöhung der anderen Parameter in diesem Substitutionsbereich ausgeglichen werden kann. Es ist weiterhin für die Einstellung einer gleichförmigen Temperaturverteilung im Verbindungsstoß zweckmäßig, die Breite des auf eine Temperatur oberhalb der Schmelztemperatur erhitzten PTFE-Streifens in ein bestimmtes Verhältnis zur Dicke der zu verbindenden Körper zu setzen. Günstige Ergebnisse werden etwa bei einem Verhältnis 0,2 :1 bis 2 :1 und insbesondere 1 :1 erzielt.It is particularly expedient, the abutment surfaces are heated to a temperature of 340-430 0 C. Below this temperature range, the necessary welding times are relatively long, while above the Breichs although very short welding times, the possibility of partial decomposition can be achieved, on the other hand, the polytetrafluoroethylene is growing. Contact pressure and swing times are preferably 30 to 150 N / cm 2 or 10 to 520 min, the parameters temperature, pressure and time acting to a certain extent in the same way, so that a lower value of one parameter by increasing the other parameters in this one Substitution area can be compensated. In order to set a uniform temperature distribution in the joint, it is also useful to set the width of the PTFE strip heated to a temperature above the melting temperature in a certain ratio to the thickness of the body to be joined. Favorable results are achieved for example at a ratio of 0.2: 1 to 2: 1 and in particular 1: 1.

Eine Vorrichtung zur Ausführung des erfindungsgemäßen Verfahrens ist dadurch gekennzeichnet daß die Polytetrafluoräthylenkörper haltenden und gegeneinanderpressenden Spannbacken mit Kühlvorrichtungen zur geregelten Ableitung der Überschußwärme aus dem erhitzten Prlytetrafluoräthylenstreifen versehen sind «o und zur Regelung des Anpreßdrucks während des Schweißvorgangs in wenigstens einer zur Stoßfläche im wesentlichen senkrechten Richtung verschiebbar sind. Längs der Schweißnaht sind zwischen den Spannbakkenpaaren zum berührungslosen Erhitzen des freien PTFE-Strei?ens Heizstrahler, z. B. in Form von Heizbändern oder Heizdrähten, angeordnet oder zum Erhitzen des freien Streifens werden in den durch die Spannbackenpaare gebildeten Spalt heiße Gase, insbesondere Luft, auf die PTFE-Oberfläche geblasen. Die so PTFE-Körper sind zweckmäßig derartig eingespannt, daß die gegeneinandergcpreßten Stoßflächen von jedem der Spannbackenpaare etwa gleich weit entfernt sind. Der Verlauf der Stoßflächen und die Gestaltung der Schweißnaht sind für das Verfahren weitgehend unkritisch. Die Stoßflächen können in einem beliebigen Winkel die Körperoberfläche schneiden, konkav und konvex ausgebildet sein oder beliebige Profile aufweisen. Die Schweißnähte sind in ihrer Längserstreckung geradlinig oder gekrümmt gestaltet. Es ist ebenso μ möglich, die Stoßflächen auf der gesamten Länge der Schweißnaht oder in bestimmten Abschnitten miteinander zu verzahnen verzahnen. Der zum Verschweißen der PTFE-Teile notwendige Druck wird unter Berücksichtigung der thermischen Dehnung des PTFE-Strei- b5 fens von außen autgebracht, auf einem bestimmten Betrag gehalten oder während der Schweißzeit nach einem vorgegebenen Programm geändert. Eine Kammerung des freien PTFE-Streifens ist dabei trotz der oberhalb des Schmelzpunktes liegenden Temperatur und des über längere Zeit aufrechterhaltenen Drucks nicht erforderlich, da insbesondere wegen der geregelten Temperaturverteilung in dem Streifen nur sehr schmale Zonen beiderseits der Stoßflächen erweichen. Die fehlende Kammerung ermöglicht die vorteilhafte Erhitzung des Polytetrafluoräthylens durch einfache Heizstrahler oder durch erhitzte Gase und vereinfacht somit das Verbindungsverfahren.An apparatus for carrying out the invention The method is characterized in that the polytetrafluoroethylene bodies hold and press against one another Clamping jaws with cooling devices for the controlled dissipation of excess heat from the heated prlytetrafluoroethylene strips are provided and for regulating the contact pressure during the Welding process are displaceable in at least one direction substantially perpendicular to the abutment surface. Along the weld seam are between the pairs of clamping jaws for contactless heating of the free PTFE strip radiant heater, e.g. B. in the form of heating bands or heating wires, arranged or for heating the free strip are placed in the through the Clamping jaw pairs formed gap hot gases, especially air, blown onto the PTFE surface. The so PTFE bodies are expediently clamped in such a way that the abutment surfaces pressed against one another by are approximately the same distance from each of the pairs of clamping jaws. The course of the abutting surfaces and the design the weld seam are largely uncritical for the process. The abutting surfaces can be in any Angle cut the body surface, be concave and convex or have any profile. The length of the weld seams is straight or curved. It is also μ possible to join the butt surfaces along the entire length of the weld or in certain sections to interlock interlock. The pressure required to weld the PTFE parts is taken into account the thermal expansion of the PTFE strip applied from the outside, on a certain Amount held or changed during the welding time according to a preset program. A chamber of the free PTFE strip is in spite of the temperature lying above the melting point and the pressure that is maintained over a longer period of time is not necessary, especially because of the regulated Temperature distribution in the strip soften only very narrow zones on both sides of the abutting surfaces. The lack of chambers enables the polytetrafluoroethylene to be advantageously heated by simple Radiant heaters or heated gases, thus simplifying the connection process.

Die Vorrichtung ist grundsätzlich ebenfalls für das Verbinden anderer thermoplastischer Kunststoffe, insbesondere von fluorhaltigen Thermoplasten mit einem höheren Erweichungspunkt und von hochschmelzenden Polymeren, wie z. B. von Polyimiden, geeignet Die für die einzelnen Kunststoffe vorteilhaften Verfahrensparameter, wie Temperatur, Druck und Zeit lassen sich jeweils durch einfache Versuche ermitteln.The device is basically also for connecting other thermoplastics, in particular of fluorine-containing thermoplastics with a higher softening point and of high-melting ones Polymers such as B. of polyimides, suitable for the individual plastics advantageous process parameters, such as temperature, pressure and time determine in each case by simple experiments.

Das erfindungsgemäße Verfahren ermöglicht in einfacher Weise die Herstellung vor stoffschlüssigen Verbindungen im Stumpfstoß von und an Formkörpern aus PTFE mit unterschiedlichen geometrischen Formen, wie Platten, Stäbe, Folien, Hohlzylindern, Hohlkegeln und dergleichen. Der als Schweißfaktor bezeichnete Quotient aus der bei Raumtemperatur ermittelten Reißfestigkeit der Verbindung und der Reißfestigkeit des massiven Ausgangsmaterials ist fast 1. Die Schweißnähte beeinträchtigen nicht die Permeabilität einer durch Verbinden mehrerer PTFE-Teile hergestellten Hohlform und ebenso wird die Beständigkeit von PTFE gegen korrosiv wirkende Stoffe durch die Verbindung nicht verändert Weitere Vorteile des Verfahrens sind die hervorragende Reproduzierbarkeit die gleichmäßige Nahtgüte und schließlich die einfache HandhabbarkeitThe method according to the invention enables the production of material connections in a simple manner Connections in the butt joint of and on molded bodies made of PTFE with different geometric shapes, such as plates, rods, foils, hollow cylinders, hollow cones and the like. The one called the sweat factor Quotient of the tensile strength of the connection determined at room temperature and the tensile strength of the solid raw material is almost 1. The weld seams do not affect the permeability a hollow shape made by joining several PTFE parts and also the resistance of PTFE against corrosive substances is not changed by the connection. Further advantages of the Process are the excellent reproducibility, the uniform seam quality and finally the simple Manageability

Die Erfindung wird im folgenden durch eine Zeichnung und durch Beispiele erläutert:The invention is illustrated below by means of a drawing and examples:

In der Figur ist der Schnitt durch eine Schweißvorrichtung schematisch dargestellt 1 und 2 sind zwei zu verbindende im Verbindungsstoß 3 gegeneinander gepreßte PTFE-Körper. die von den Spannbackenpaaren 4 gehalten sind, wobei die aufgebrachten Kräfte durch Pfeile A dargestellt sind Zum Aufbringen des notwendigen Schweißdrucks sind die Backen 4 in Richtung des Verbindungsstoßes 3 verschiebbar und pressen mit der durch Federn, hydraulische Mittel oder Gewichten und dergleichen erzeugten Kraft B die Stoßflächen gegeneinander. Zwischen den Spannbakken sind zum Erwärmen des Polytetrafluoräthylens im Bereich des Verbindungsstoßes 3 Heizstrahler S angeordnet. Zur Regelung der Temperaturvcrteilung im Schweiß- und Einspannbereich enthalten die Spannbakken 4 Kühlvorrichtungen 6 oder Kühlmittel mit einer hohen Wärmekapazität oder die Wärmekapazität der Spannbacken selbst ist hinreichend groß, um während des Schweißvorgangs eine bestimmte Temperaturverteilung zwischen Spannbacken und Verbindungsstoß aufrechtzuerhalten.In the figure, the section through a welding device is shown schematically. 1 and 2 are two PTFE bodies to be connected in the joint 3 pressed against one another. which are held by the clamping jaw pairs 4, wherein the applied forces are illustrated by arrows A are to apply the necessary welding pressure, the jaws 4 in the direction of the connecting joint 3 movable and presses with by springs, hydraulic means or weights, and the like generated force B, the abutment surfaces against each other. Between the clamping jaws 3 radiant heaters S are arranged for heating the polytetrafluoroethylene in the area of the connecting joint. To regulate the temperature distribution in the welding and clamping area, the clamping jaws 4 contain cooling devices 6 or coolant with a high thermal capacity or the thermal capacity of the clamping jaws themselves is large enough to maintain a certain temperature distribution between the clamping jaws and the joint during the welding process.

Die Funktionsweise der Vorrichtung wird anhand des folgenden Beispiels näher erläutertThe method of operation of the device is explained in more detail using the following example

Beispielexample

Zur Auskleidung eines Trichters mit öffungsdurchmessern von 1400 mm bzw. 500 mm und einer Höhe von 1000 mm wurde ei/is zugeschnittene und an den Stoßflächen plangehobelte PTFE-Folie mit einer Dicke von 4 mm derartig in die Vorrichtung nach der Figur gespannt, daß der Verbindungsstoß etwa gleich weitFor lining a funnel with opening diameters of 1400 mm or 500 mm and a height of 1000 mm was cut to size and attached to the Butt surfaces planed PTFE film with a thickness of 4 mm in this way in the device according to the figure excited that the connection joint is about the same distance

von den Spannbackenpaaren entfernt war und parallel zu den Backen verlief. Der Abstand der Spannbacken betrug 10 mm. Die Zone beiderseits des VerbindungsstoBes wurde durch die Heizstrahler auf ca.4000C erhitzt, bei der ein Gleichgewicht zwischen der durch Strahlung in die etwa 5 mm breite Schweißzone eingebrachte und durch Leitung über die Spannbacken abgeführte Energie bestand. Die Temperatur und ein Druck von 60 N/cm2 wuHen für 40 min. aufrechterhalten und die Schweißzone dann unter Druck au Raumtemperatur abgekühlt. Die sich beiderseits de Stoßflächen ausgebildeten Nahtverdickungen wurdet dann abgehobelt und kerbenfreie Oberflächen geschaf fen. Im Vergleich zu nichtverschweißtem PTFE hatti die Schweißnaht folgende Eigenschaftenwas removed from the pairs of jaws and ran parallel to the jaws. The distance between the clamping jaws was 10 mm. The zone either side of the VerbindungsstoBes was heated by the heater to about 400 0 C at which an equilibrium between the radiation introduced into the approximately 5 mm wide fusion zone and dissipated by conduction through the clamping jaws consisted energy. The temperature and a pressure of 60 N / cm 2 were maintained for 40 minutes and the welding zone was then cooled to room temperature under pressure. The thickened seams formed on both sides of the abutment surfaces were then planed off and notch-free surfaces were created. Compared to non-welded PTFE, the weld seam has the following properties

Bruchfestigkeit
BruchdehnungBreaking strength
Elongation at break

>0.8
>0,9> 0.8
> 0.9

Hierzu 1 Blatt Zeichnungen1 sheet of drawings

Claims (4)

Patentansprüche:Patent claims: 1. Verfahren zum Verbinden von Formkörpern aus gesintertem Polytetrafluorethylen im Stumpfstoß, nach welchem die aneinandergepreßten Stoßflächen auf eine Temperatur oberhalb von 327° C erhitzt werden, dadurch gekennzeichnet, daß die Formkörper bis auf einen schmalen, die Stoßflächen einschließenden Streifen zwischen gekühlten Spannbacken eingespannt werden, der Streifen durch Strahlung und/oder konvektiv berührungslos erhitzt wird, beim Zusammenpressen der Stoßflächen eine Nahtverdickung erzeugt wird und die Verdickung anschließend abgearbeitet wird.1. Process for connecting molded bodies made of sintered polytetrafluoroethylene in a butt joint, after which the abutting surfaces pressed together to a temperature above 327 ° C are heated, characterized in that the shaped body except for a narrow one, the Strips enclosing abutment surfaces are clamped between cooled clamping jaws, the Strip is heated without contact by radiation and / or convectively when the Joint surfaces a seam thickening is generated and the thickening is then processed. 2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß Temperatur und Druck im Schweißstoß 10—120 Minuten aufrechterhalten werden.2. The method according to claim 1, characterized in that the temperature and pressure in the weld joint Maintained for 10-120 minutes. 3. Verfahren nach Anspruch 1 bis 2, dadurch gekennzeichnet, daß die Breite des erhitzten Streifens das 9,2- bis 2fache, vorzugsweise das 1 fache der Körperdicke beträgt.3. The method according to claim 1 to 2, characterized in that the width of the heated Strip 9.2 to 2 times, preferably 1 times the body thickness is. 4. Vorrichtung zur Durchführung des Verfahrens nach Anspruch 1, dadurch gekennzeichnet, daß die die Polytetrafluoräthylenkörper haltenden und gegeneinanderpressenden Spannbacken mit Kühlvorrichtungen zur geregelten Ableitung der Wärme aus dem erhitzten Polytetrafluoräthylenstreifen versehen sind und zur Regelung des Anpreßdrucks während des Schweiß Vorgangs in wenigstens einer zur Stoßfläche iniwesentlichen senkrechten Richtung verschiebbar sind.4. Apparatus for performing the method according to claim 1, characterized in that the holding the polytetrafluoroethylene bodies and pressing them against one another The clamping jaws are provided with cooling devices for the controlled dissipation of heat from the heated polytetrafluoroethylene strips are and for regulating the contact pressure during the welding process in at least one are displaceable in an essentially perpendicular direction to the abutment surface.
DE2549475A 1975-11-05 1975-11-05 Method and device for connecting molded bodies made of polytetrafluoroethylene Expired DE2549475C3 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
DE2549475A DE2549475C3 (en) 1975-11-05 1975-11-05 Method and device for connecting molded bodies made of polytetrafluoroethylene
IT29034/76A IT1063650B (en) 1975-11-05 1976-11-03 PROCESS AND DEVICE TO CONNECT BODIES FORMED IN POLYTETRAFLUOROETHYLENE
GB45932/76A GB1570686A (en) 1975-11-05 1976-11-04 Joining of polytetrafluoroethylene bodies
JP51131799A JPS5263275A (en) 1975-11-05 1976-11-04 Method for connecting formed products consisted of polyyfluorooethylene and apparatus therefor
FR7633413A FR2330518A1 (en) 1975-11-05 1976-11-05 METHOD OF ASSEMBLING MOLDED OBJECTS BASED ON POLY- (TETRAFLUORETHYLENE) AND DEVICE INTENDED FOR ITS IMPLEMENTATION
US05/867,533 US4197149A (en) 1975-11-05 1978-01-06 Method for joining together shaped bodies of polytetrafluoroethylene

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2549475A DE2549475C3 (en) 1975-11-05 1975-11-05 Method and device for connecting molded bodies made of polytetrafluoroethylene

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DE2549475A1 DE2549475A1 (en) 1977-05-18
DE2549475B2 DE2549475B2 (en) 1977-11-24
DE2549475C3 true DE2549475C3 (en) 1979-04-19

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DE2549475A Expired DE2549475C3 (en) 1975-11-05 1975-11-05 Method and device for connecting molded bodies made of polytetrafluoroethylene

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JP (1) JPS5263275A (en)
DE (1) DE2549475C3 (en)
FR (1) FR2330518A1 (en)
GB (1) GB1570686A (en)
IT (1) IT1063650B (en)

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Publication number Priority date Publication date Assignee Title
US4283448A (en) * 1980-02-14 1981-08-11 W. L. Gore & Associates, Inc. Composite polytetrafluoroethylene article and a process for making the same
CA1243169A (en) * 1984-07-09 1988-10-18 Michael L. Osgar Welding fluoropolymer pipe and fittings
DE3708705A1 (en) * 1987-03-18 1988-10-06 Gruber Alois & Sohn Agru METHOD AND DEVICE FOR WELDING TUBULAR PLASTIC PARTS
US4990296A (en) * 1989-08-21 1991-02-05 Garlock Inc. Welding of filled sintered polytetrafluoroethylene
FR2655533A1 (en) * 1989-12-13 1991-06-14 Lefebvre Jean Marie FILTER CATHETER.
US6086806A (en) * 1996-04-05 2000-07-11 Ronald H. Ball Method of splicing thermoplastic articles
KR102620420B1 (en) * 2019-09-24 2024-01-03 다이킨 고교 가부시키가이샤 weld body
GB2623080A (en) * 2022-10-03 2024-04-10 Shearwell Data Ltd Method for joining parts of animal identification tag

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2914438A (en) * 1956-03-26 1959-11-24 Du Pont Bonding polytetrafluoroethylene resins
FR1207226A (en) * 1958-10-31 1960-02-15 Applic Mecaniques Soc Et Hoop for physical training, dance, games and similar purposes
FR1221831A (en) * 1959-01-15 1960-06-03 Improvements in the manufacture of hollow bodies with a convex surface, in particular in polytetrafluoroethylene
US3207644A (en) * 1959-07-20 1965-09-21 Garlock Inc Method of making a fluorocarbon resin jacketed gasket
FR2036084A5 (en) * 1969-03-04 1970-12-24 Resines Extrudees Moulee Welding polytetrafluorethylene sheets and - pieces
DE2311096C3 (en) * 1973-03-06 1981-08-20 Hoechst Ag, 6000 Frankfurt Process for connecting molded articles containing polytetrafluoroethylene

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DE2549475A1 (en) 1977-05-18
FR2330518B1 (en) 1981-12-11
FR2330518A1 (en) 1977-06-03
DE2549475B2 (en) 1977-11-24
IT1063650B (en) 1985-02-11
JPS5263275A (en) 1977-05-25
GB1570686A (en) 1980-07-09

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