GB2082500A - A method and apparatus for welding sheets of thermoplastic material - Google Patents

A method and apparatus for welding sheets of thermoplastic material Download PDF

Info

Publication number
GB2082500A
GB2082500A GB8122383A GB8122383A GB2082500A GB 2082500 A GB2082500 A GB 2082500A GB 8122383 A GB8122383 A GB 8122383A GB 8122383 A GB8122383 A GB 8122383A GB 2082500 A GB2082500 A GB 2082500A
Authority
GB
United Kingdom
Prior art keywords
wedge
sheets
thermoplastic material
overlapping edges
hot
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.)
Withdrawn
Application number
GB8122383A
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.)
Gundle Holdings Pty Ltd
Original Assignee
Gundle Holdings Pty Ltd
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 Gundle Holdings Pty Ltd filed Critical Gundle Holdings Pty Ltd
Publication of GB2082500A publication Critical patent/GB2082500A/en
Withdrawn legal-status Critical Current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
    • 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
    • B29C65/40—Applying molten plastics, e.g. hot melt
    • B29C65/42—Applying molten plastics, e.g. hot melt between pre-assembled parts
    • 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
    • B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
    • B29C65/20—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools with direct contact, e.g. using "mirror"
    • 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
    • B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
    • B29C65/22—Heated wire resistive ribbon, resistive band or resistive strip
    • B29C65/221—Heated wire resistive ribbon, resistive band or resistive strip characterised by the type of heated wire, resistive ribbon, band or strip
    • B29C65/224—Heated wire resistive ribbon, resistive band or resistive strip characterised by the type of heated wire, resistive ribbon, band or strip being a resistive ribbon, a resistive band or a resistive strip
    • 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
    • B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
    • B29C65/24—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools characterised by the means for heating the tool
    • B29C65/26—Hot fluid
    • 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
    • B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
    • B29C65/24—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools characterised by the means for heating the tool
    • B29C65/28—Flame or combustible material
    • 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
    • B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
    • B29C65/24—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools characterised by the means for heating the tool
    • B29C65/30—Electrical means
    • B29C65/32—Induction
    • 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
    • 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
    • B29C65/52—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 way of applying the adhesive
    • B29C65/524—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 way of applying the adhesive by applying the adhesive from an outlet device in contact with, or almost in contact with, the surface of the part 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
    • B29C65/72—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by combined operations or combined techniques, e.g. welding and stitching
    • 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
    • B29C66/70—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
    • B29C66/80—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
    • B29C66/836—Moving relative to and tangentially to the parts to be joined, e.g. transversely to the displacement of the parts to be joined, e.g. using a X-Y table
    • B29C66/8362—Rollers, cylinders or drums moving relative to and tangentially to 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
    • B29C66/90—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
    • B29C66/912—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux
    • B29C66/9121—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux by measuring the temperature
    • B29C66/91211—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux by measuring the temperature with special temperature measurement means or methods
    • B29C66/91212—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux by measuring the temperature with special temperature measurement means or methods involving measurement means being part of the welding jaws, e.g. integrated in the welding jaws
    • 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
    • B29C66/912—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux
    • B29C66/9121—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux by measuring the temperature
    • B29C66/91231—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux by measuring the temperature of the joining tool
    • 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
    • B29C66/91421—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 joining tools
    • 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
    • B29C66/91651—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 by controlling or regulating the heat generated by Joule heating or induction heating
    • 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
    • B29C66/91651—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 by controlling or regulating the heat generated by Joule heating or induction heating
    • B29C66/91655—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 by controlling or regulating the heat generated by Joule heating or induction heating by controlling or regulating the current intensity
    • 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
    • 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
    • B29C65/1403—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 type of electromagnetic or particle radiation
    • B29C65/1412—Infrared [IR] radiation
    • 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
    • B29C65/18—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated tools
    • B29C65/22—Heated wire resistive ribbon, resistive band or resistive strip
    • B29C65/228—Heated wire resistive ribbon, resistive band or resistive strip characterised by the means for electrically connecting the ends of said heated wire, resistive ribbon, resistive band or resistive strip
    • 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
    • B29C66/024—Thermal pre-treatments
    • B29C66/0242—Heating, or preheating, e.g. drying
    • 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
    • B29C66/91651—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 by controlling or regulating the heat generated by Joule heating or induction heating
    • B29C66/91653—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 by controlling or regulating the heat generated by Joule heating or induction heating by controlling or regulating the voltage, i.e. the electric potential difference or electric tension
    • 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
    • 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
    • B29C66/95—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94
    • B29C66/953—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94 by measuring or controlling the humidity
    • B29C66/9532—Measuring or controlling the joining process by measuring or controlling specific variables not covered by groups B29C66/91 - B29C66/94 by measuring or controlling the humidity of the parts to be joined, i.e. taking the humidity 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
    • B29C66/96—Measuring or controlling the joining process characterised by the method for implementing the controlling of the joining process
    • B29C66/961—Measuring or controlling the joining process characterised by the method for implementing the controlling of the joining process involving a feedback loop mechanism, e.g. comparison with a desired value

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)

Abstract

Sheets of thermoplastic material are welded together by passing a hot wedge 5 between overlapping edges 3, 4 of the sheets so as to melt the surfaces 1, 2 of the sheets in contact with the wedge, adding a small amount of molten thermoplastic material between the overlapping edges and thereafter pressing the edges together, e.g. by a roller 7, so that when they have cooled any voids and creases are filled with the additional thermoplastic material. The wedge 5 may be heated by an induction coil 6, Fig. 1, or by the passage of a high amperage low voltage electric current therethrough, Fig. 2 (not shown). The temperature of the wedge is controlled by a controller connected to a temperature sensing device 8 located at the pointed end of the wedge. The additional thermoplastic material may be supplied through a nozzle (18), Fig. 3 (not shown), near the pointed end of the wedge. Alternatively, this material is introduced at the side of the wedge and the roller, Fig. 4 (not shown). <IMAGE>

Description

SPECIFICATION A method and apparatus for welding thermoplastic material THIS INVENTION relates to a method for welding thermoplastic material and more particularly thermoplastic sheets or panels and to an apparatus effecting this method.
In the overlap welding of thermoplastic sheets or panels the overlapping edges or facing surfaces thereof are generally welded in one of the following ways: (a) The surfaces are heated to above melting temperature by a heated metal wedge which is passed over them. The melted surfaces are then pressed together until the material has dropped below the melting point and has solidified.
(b) The surfaces are heated to a specified temperature usually below the melting point using a preheater. Th ensure proper melting of the sheets for welding additional heat is then supplied by adding further molten thermoplastic material in a sufficient quantity and at a high enough temperature to ensure melting of the surfaces of two sheets to be joined.
The surfaces are then pressed together so that welding takes place as the temperature of the material drops to below its melting point.
Thus in the above cases the heat for melting and/or preheating is supplied in known manner by either: (i) a hot metal wedge to which heat is supplied by conduction; the heat source being typically an electric element, a direct flame, or a hot gas; (ii) a jet of hot gas such as air, which is heated typically by an electric element or a flame; (iii) radiation typically in the infrared part of the spectrum but also including radiation of other suitable wave lengths.
To ensure a constant welding temperature in cases (ii) and (iii) it is necessary to sense the temperature of the thermoplastic sheets to be welded and to vary the heat input so as to compensate for temperature variations. Temperature sensing does not however cope with factors such as moisture on the sheets which requires additional heat for vaporisation thereby causing the surface temperature to be lower than required.
To ensure a constant welding temperature where the hot wedge is in contact with the sheet in cases (a) and (i) above, it is sufficient to sense the temperature of the wedge as near to the working surface of the wedge as possible and to compensate for temperature variations by adjusting the heat input. The time lag caused by conduction of the heat into the wedge can result in inconsistent welding.
Another problem typical to welding/joining method (a) arises where the joint has to be both mechanically sound, and leakproof.
Where the edges of the sheets to be joined are not absolutely flat, small waves of material form ahead of the welding wedge. These waves occasionally pass over the welding wedge as a crease which is not welded and thus forms a passage for fluid.
An object of this invention is to provide an improved process and apparatus for welding sheets of thermoplastic material together.
According to the invention a method of welding sheets of thermoplastic material to gether comprises the steps of: (i) positioning two sheets to be welded such that they are substantially adjacent each other with a pair of their edges in overlapping relationship; (ii) passing a hot wedge between the overlapping edges to contact the adjacent surfaces of both sheets, the wedge being at a temperature high enough to melt both surfaces; (iii) adding an amount of molten thermoplastic material between the overlapping edges and (iv) pressing the overlapping edges together and allowing them to cool, so that the surfaces are joined substantially completely by the thermoplastic material of the sheets and any voids or creases are filled by the additional amount of thermoplastic material.
Further according to this aspect of the invention the additional thermoplastic material is added between overlapping edges at a position substantially adjacent the part of the surfaces melted by the hot wedge.
According to a second aspect of the invention a hot wedge for use in welding the overlapping edges of thermoplastic sheets comprises: a wedge of suitable material and means for heating the wedge in the form of a controlled induction coil or the like.
According to a third aspect of the invention a hot wedge for use in welding the overlapping edges of thermoplastic sheets comprises: a wedge of suitable material and resistance heating means for the wedge including means for passing a high amperage, low voltage, current through the wedge.
Further according to the invention the wedges of both the second and the third aspect of the invention include a temperature sensing device embodied therein for controlling the heating means for the wedge.
Three embodiments of the invention described by way of example only follow with reference to the accompanying drawings in which: Figure 1 is a schematic elevation of overlapping sheets of thermoplastic material being joined by a wedge of the first embodiment; Figure 2 is a schematic elevation of overlapping sheets of thermoplastic material being joined by a wedge of the second embodiment; Figure 3 is a schematic elevation of overlapping edges of thermoplastic material being joined together using additional thermoplastic material; Figure 4 is an end elevation of two overlapping sheets of thermoplastic material the edges of which have been joined together using a hot wedge and additional thermoplastic material.
In the first embodiment of the invention as shown in Fig. 1 the adjacent surfaces 1 and 2 of the overlapping edges 3 and 4 of two sheets of thermoplastic material are joined together using a hot wedge 5. This hot wedge 5 is heated using an externally placed induction coil 6.
The hot wedge is moved between the surfaces 1 and 2 in the direction shown by arrow X. As it moves it melts the surfaces which are then squeezed together by means of a roller 7. In this way the molten material of the surfaces 1 and 2 are brought into contact and solidify together as the temperature of the material drops below its melting point, thus welding the sheets together.
To control the temperature of the hot wedge 5 a temperature sensing device 8 is located in the hot wedge as near as possible to the pointed end 9 thereof. This device is connected to a controller (not shown) which controls the induction coil 6 which heats the hot wedge.
In the second embodiment of the invention as shown in Fig. 2 two sheets of thermoplastic material are joined together in the same manner described above, however in this case a different type of hot wedge is used. The hot wedge 10 of this embodiment comprises a shell 11 of suitable resistance material. This shell 11 is connected at its ends 12 and 13 to electrical leads 14 and 15. A high amperage, low voltage current is supplied to the hot wedge by the leads 14 and 15 thereby heating the hot wedge to a suitable temperature.
As in the previous embodiment a temperature sensing device 16 is positioned near the tip 17 of the wedge. This device 16 controls the current flowing through the wedge in known manner and in this way controls the temperature of the wedge.
In both of the embodiments described above, a small amount of additional molten thermoplastic material may be introduced between the surfaces 1 and 2 after they have been melted by the wedge but prior to squeezing by the roller 7. This material may be introduced via a nozzle 18 located near the tip or trailing edge 19 of a wedge 20 as shown in Fig. 3.
As the roller squeezes the two sheets of material together their molten surfaces 1 and 2 are contacted in the manner described above. The additional molten thermoplastics material collects in any voids or creases where the two surfaces have not welded, thereby ensuring continuity and completeness of the weld.
One cause of such creases which may lead to leaks in the join is shown in Fig. 3. As the two sheets move under the roller 7 it often happens that a small wave of material builds up in one of the sheets in front of the roller 7.
These waves occasionally pass under the roller in the form of a crease 21. The additional material 22 collects in and seals these creases as described above.
An alternative to this embodiment is shower in Fig. 4. Here instead of introducing the additional thermoplastic material at a position" between the tip of the wedge and the roller it is introduced to the side of these two devices.
As the roller squeezes the surfaces together this additional thermoplastic material collects in the form of a bead 23 beside the welded surfaces thus sealing off any leaks or voids which may be present. Here it should be noted that the heat from the additional molten material melts the surfaces thereby effecting a similar welding mechanism.
From the embodiments described above it is apparent that the invention provides a novel method for welding together the overlapping edges of sheets of thermoplastic material.
Furthermore this welding is done in an efficient, leak proof manner using hot wedges the temperatures of which may be easily and relatively accurately controlled.
Other embodiments are envisaged within the scope of the invention.

Claims (7)

1. A method of welding sheets of thermoplastic material together comprising the steps of: (i) positioning two sheets to be welded such that they are substantially adjacent each other with a pair of their edges in overlapping relationship; (ii) passing a hot wedge between the overlapping edges to contact the adjacent surfaces of both sheets, the wedge being at a temperature high enough to melt both surfaces; (iii) adding an amount of molten thermoplastic material between the overlapping edges and (iv) pressing the overlapping edges together and allowing them to cool, so that the surfaces are joined substantially completely by the thermoplastic material of the sheets and any voids and creases are filled by the additional amount of thermoplastic material.
2. A method as claimed in claim 1 in which the additional thermoplastic material is added between the overlapping edges at a position substantially adjacent the part of the surfaces melted by the hot wedge.
3. A hot wedge for use in welding the overlapping edges of thermoplastic sheets comprising a wedge of suitable material and means for heating the wedge in the form of one of a controlled induction coil and means for passing a high amperage law voltage current through the wedge.
4. A hot wedge as claimed in claim 3 which includes a temperature sensing device embodied therein for controlling the heating means for the wedge.
5. An apparatus including a hot wedge as claimed in either of claims 3 and 4; means for introducing additional molten plastics material between the overlapping edges after passage of the hot wedge and means for pressing the overlapping edges together after introduction of the molten plastics material.
6. A method substantially as herein described with reference to any of the accompanying drawings.
7. An apparatus substantially as herein described with reference to any of the accompanying drawings.
GB8122383A 1980-08-22 1981-07-21 A method and apparatus for welding sheets of thermoplastic material Withdrawn GB2082500A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
ZA805190 1980-08-22

Publications (1)

Publication Number Publication Date
GB2082500A true GB2082500A (en) 1982-03-10

Family

ID=25574889

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8122383A Withdrawn GB2082500A (en) 1980-08-22 1981-07-21 A method and apparatus for welding sheets of thermoplastic material

Country Status (9)

Country Link
JP (1) JPS5772814A (en)
AU (1) AU7315781A (en)
BR (1) BR8105241A (en)
DE (1) DE3132273A1 (en)
FR (1) FR2488828A1 (en)
GB (1) GB2082500A (en)
IL (1) IL63415A0 (en)
IT (1) IT1138164B (en)
NL (1) NL8103851A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1990009270A1 (en) * 1989-02-15 1990-08-23 Coloplast A/S A method and an apparatus for welding together plastics foil strips
EP0414414A2 (en) * 1989-08-10 1991-02-27 Shaw Industries Ltd. Heat shrinkable protective sheets and methods for their manufacture
US5134000A (en) * 1989-08-10 1992-07-28 Shaw Industries Ltd. Heat shrinkable protective sheets and methods for their manufacture
ITMI20081418A1 (en) * 2008-07-30 2010-01-31 Sestese Off Mec WELDING DEVICE FOR PASSING FOR A PLASTIC STRAP AND ITS WELDING METHOD.
EP1866142A4 (en) * 2005-04-08 2015-03-04 Nat Res Council Canada Resistance welding of thermoplastics
CN112739528A (en) * 2018-07-16 2021-04-30 阿科玛法国公司 Method for welding thermoplastic material parts
FR3108553A1 (en) * 2020-03-24 2021-10-01 Arkema France Welding process of parts based on thermoplastic material
US12076937B2 (en) 2019-11-27 2024-09-03 Arkema France Method for evaluating an assembly by welding of parts based on thermoplastic materials

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04364926A (en) * 1991-06-11 1992-12-17 Adoheya Sansho Kk Method for bonding waterproof sheet and waterproof cloth
JPH06327096A (en) * 1993-11-16 1994-11-25 Sony Corp Electroacoustic transducer
DE19741686B4 (en) * 1997-09-18 2005-10-13 Andreas Schmidt Device and method for joining, in particular hot wedge overlap welding, of plastic sheets
CN104889613B (en) * 2015-05-15 2017-03-15 江苏金晟元特种阀门股份有限公司 Intelligent welding technique
US10703049B2 (en) 2018-06-20 2020-07-07 Spirit Aerosystems, Inc. System and method for welding thermoplastic components to create composite structure
FR3083733A1 (en) * 2018-07-16 2020-01-17 Arkema France Method of induction welding of parts based on thermoplastic material
FR3083734B1 (en) * 2018-07-16 2021-12-24 Arkema France INDUCTION WELDING PROCESS FOR PARTS BASED ON THERMOPLASTIC MATERIAL
FR3083732A1 (en) * 2018-07-16 2020-01-17 Arkema France Method for welding parts based on thermoplastic material

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1990009270A1 (en) * 1989-02-15 1990-08-23 Coloplast A/S A method and an apparatus for welding together plastics foil strips
EP0414414A2 (en) * 1989-08-10 1991-02-27 Shaw Industries Ltd. Heat shrinkable protective sheets and methods for their manufacture
EP0414414A3 (en) * 1989-08-10 1991-11-06 Shaw Industries Ltd. Heat shrinkable protective sheets and methods for their manufacture
US5134000A (en) * 1989-08-10 1992-07-28 Shaw Industries Ltd. Heat shrinkable protective sheets and methods for their manufacture
EP1866142A4 (en) * 2005-04-08 2015-03-04 Nat Res Council Canada Resistance welding of thermoplastics
ITMI20081418A1 (en) * 2008-07-30 2010-01-31 Sestese Off Mec WELDING DEVICE FOR PASSING FOR A PLASTIC STRAP AND ITS WELDING METHOD.
CN112739528A (en) * 2018-07-16 2021-04-30 阿科玛法国公司 Method for welding thermoplastic material parts
US11685125B2 (en) 2018-07-16 2023-06-27 Arkema France Method for welding parts made of thermoplastic material
US12076937B2 (en) 2019-11-27 2024-09-03 Arkema France Method for evaluating an assembly by welding of parts based on thermoplastic materials
FR3108553A1 (en) * 2020-03-24 2021-10-01 Arkema France Welding process of parts based on thermoplastic material

Also Published As

Publication number Publication date
JPS5772814A (en) 1982-05-07
IT8123596A0 (en) 1981-08-21
BR8105241A (en) 1982-04-27
IT1138164B (en) 1986-09-17
DE3132273A1 (en) 1982-04-01
NL8103851A (en) 1982-03-16
AU7315781A (en) 1982-02-25
FR2488828A1 (en) 1982-02-26
IL63415A0 (en) 1981-10-30

Similar Documents

Publication Publication Date Title
GB2082500A (en) A method and apparatus for welding sheets of thermoplastic material
US4913772A (en) Portable thermoplastic welding machine
EP0387512B1 (en) An arrangement for continuous induction welding
EP0281347B1 (en) Bonding thermoplastic layers
US4695335A (en) Method for developing a predetermined fusing temperature in thermoplastic items
US3106630A (en) Sealing apparatus
DK0430762T3 (en) Method and apparatus for detecting the heating state of a portion of thermoplastic material and connector for welding plastic material elements
US4353770A (en) Method for welding the inner layers of multi-layer paper sacks
EP0480405B1 (en) An apparatus for induction welding
US3016085A (en) Apparatus for heat sealing a thermoplastic web in which the heat is controlled by the speed of the web
US1857505A (en) Method of butt welding by means of alpha flashing electric arc
US2157732A (en) Method of joining sheets
US4771151A (en) Self-heating lid for soldering to a box
EP0610762B1 (en) Method for production weld planishing of plastic sheet and joint
CA1168138A (en) Welding of plastics material
US3080910A (en) Hot gas thermoplastic welding apparatus
JPS62288029A (en) Vessel made of resin and bonded by fusion, and fusion bonding thereof
US6524434B1 (en) Tubular device in a bagging machine
US3146564A (en) Apparatus for closing and sealing bag tops
US4243449A (en) Process for sealing a plurality of polybutylene sheets
SE8304252L (en) HEAT WELDING OF THERMOPLASTIC MATERIAL
JP2003191922A (en) Method and apparatus for peeling sealed part of paper container
SU1204395A1 (en) Method of butt welding of thermoplastic materials
JPS6262734A (en) Jointing of thermoplastic resin with laser
JPH04339999A (en) Waterproof sheet

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)