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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F3/00—Severing by means other than cutting; Apparatus therefor
  • B26F3/06—Severing by using heat
  • B26F3/08—Severing by using heat with heated members
  • B26F3/12—Severing by using heat with heated members with heated wires
• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C66/00—General aspects of processes or apparatus for joining preformed parts
  • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
  • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
  • B29C66/43—Joining a relatively small portion of the surface of said articles
  • B29C66/431—Joining the articles to themselves
• • 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
  • B29C66/9141—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
  • B29C66/91641—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 the heat or the thermal flux being non-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
  • 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
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B61/00—Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages
  • B65B61/04—Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages for severing webs, or for separating joined packages
  • B65B61/06—Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages for severing webs, or for separating joined packages by cutting
  • B65B61/10—Auxiliary devices, not otherwise provided for, for operating on sheets, blanks, webs, binding material, containers or packages for severing webs, or for separating joined packages by cutting using heated wires or cutters
• • 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

Definitions

• Packing machine such as a packing table for wrapping up goods in a plastics foil.
• the present invention relates to a packing machine such as a packing table for wrapping up goods in a plastics foil taken off from a supply, and where pro ⁇ vision is made of a heatable tear-off edge for separating from the supply, by thermal action on the foil, a piece of foil to be used for the wrapping.
• a packing machine such as a packing table for wrapping up goods in a plastics foil taken off from a supply
• pro ⁇ vision is made of a heatable tear-off edge for separating from the supply, by thermal action on the foil, a piece of foil to be used for the wrapping.
• the heating wire or rod which acts as a cutting or tear-off edge is a resistance wire or a hollow rod provided with a resistance heating element of con ⁇ ventional type heated by passage of current, and when the foil which for instance is drawn in the desired lengths from a supply roller is brought into contact with the heating wire, it will be separated or cut at the area of contact as a result of the decomposing action of the heat on the plastics material.
• the temperature at which the heating wire or rod acts on the plastics foil is, however, very critical. If the temperature is too low, the cutting effect will be insufficient and if it is too high, the decomposition of the plastics material may result in a combustion producing vapours and/or gases and also in many cases ashes, which is troublesome and sometimes detrimental to the operator of the machine and, in any case, unacceptable when the packing machine is used for wrapping up articles of food, e.g. meat products, which may be contaminated thereby.
• the invention has for its object to provide a packing machine such as a packing table which prevents effectively the formation of injurious gases or vapours, when plastics foil lengths are cut or torn off by thermal action thereon and which therefore can also be used for packing articles of food, said' machine being nevertheless of simple, cheap and robust construction, so that it can stand a rough treatment.
• the machine according to the invention is charac ⁇ terized in that the tear-off edge is provided with one or more PTC elements as a heating body.
• the invention utilizes the fact that whereas the resistance/temperature characteristic of ordinary resistance materials is practically continuous, this characteristic shows for PTC materials, which ar.e ceramic materials on the basis of barium titanate, an abrupt and very steep increase at a definite temperature, the so- called Curie temperature, the level of which can be adjusted when preparing the material, the resistance value increasing very strongly when the temperature exceeds this Curie temperature.
• PTC materials ar.e ceramic materials on the basis of barium titanate
• Curie temperature the level of which can be adjusted when preparing the material
• the passage of current is thereby limited correspondingly and the production of heat connected therewith too, so that a temperature balance is established at the Curie temperature.
• Fig. 1 shows a packing table having a tear-off edge in the form of a heating rod according to the invention
• Fig.2 the heating rod dismounted from the packing table shown in Fig.1
• Fig.1 shows a packing table having a tear-off edge in the form of a heating rod according to the invention
• Fig.3 a sectional view of the heating rod of Fig.2.
• the packing table shown in Fig.1 comprises a packing surface A provided, on its side turning away from the operator, with a supply roll B with the plastics foil to be used for wrapping up goods such as articles of food.
• the supply roll B rests on two rollers E extending across the width of the packing table, and the free end of the foil is led down in front of the rollers E or between these and passes underneath the packing surface A until it reaches the front of said surface, where provision is made of an additional roller F over which the foil can be drawn up to the top side of the packing surface.
• the operator places the article to be wrapped up on the packing surface A and then draws a suitable length of foil towards the front of the packing surface, over the roller F and over the article which is then taken from above and moved towards the operator onto a surface C which may possibly be a heat plate, if the foil is of the shrinking type.
• a surface C which may possibly be a heat plate, if the foil is of the shrinking type.
• the heating rod D is shown dismounted and with a current supply wire in Fig. 2, and a longitudinal section of a central part of the heating rod is shown in Fig.3.
• the heating rod D comprises a tubular envelope 1 which may be of aluminium or any other heat resistant material and may have a triangular, circular or rectangular profile.
• an insulating layer 2 which may be an extruded silicone rubber profile inserted in the envelope 1.
• electric conductors 3 are inserted in the rubber profile, which conductors may be aluminium or brass foil strips extending along the whole length of the heating rod and being insulated from each other. These conductors 3 are connected each to one pole of the electric feed voltage source (not shown) , e.g. via a wire with a plug as shown in Fig.2. Between the electric conductors 3 and in contact therewith, heating elements 5 of PTC material are inserted in the heating rod, said elements being, in the embodiment shown, kept at a distance from each other by means of insulating- spacers 4 which may be made of silicone rubber and are practically filling up the intervals between the PTC elements. In principle, the heating rod could also be filled up with PTC material,
• the number of PTC heating elements 5 per unit of length or the degree of filling of the heating rod depends on the Curie temperature of the PTC material and of the desired surface temperature of the heating rod. If the Curie temperature of the PTC material corresponds practically to the desired cutting temperature determined by the plastics foil material, the heating rod can be filled up with this PTC material, and if the Curie temperature is higher than the desired cutting temperature, the degree of filling of the heating rod is chosen proportionally lower, which can take place by inserting two or more smaller PTC elements at a suitable distance from each other in the heating rod, for instance as shown in Fig.3.
• the heating rod D is connected to the feed voltage, e.g. via an electric wire as shown in Fig.2, and the rod will very quickly reach the desired surface temperature at which the plastics used as wrapping material is just decomposed but not burnt.
• the heating rod is so dimensioned as to produce this surface temperature depending on the wrapping material used.
• the desired surface temperature of the heating rod will be reached but not exceeded to an appreciable extent, so that even after an operative break where no cutting and thus no cooling of the heating rod has taken place, the wrapping foil will be cut solely by decomposition of the plastics material but without combustion of said material and consequently, without " formation of unpleasant and possibly injurious vapours and gases, and without production of ashes.
• a packing table according to the invention is thus extremely cleanly in use, because the cutting of the plastics foil produces no waste at all, and even very severe sanitary regulations as those imposed in particular by the veterinary services for the packing of articles of food may be met safely and without difficulty.
• the invention provides a tear-off edge of very simple construction, working in a safe and reliable manner and requiring practically no maintenance.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Forests & Forestry (AREA)
• Containers And Plastic Fillers For Packaging (AREA)
• Auxiliary Devices For And Details Of Packaging Control (AREA)
• Auxiliary Apparatuses For Manual Packaging Operations (AREA)
• Basic Packing Technique (AREA)
• Resistance Heating (AREA)
• Package Closures (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8106579

Family Applications (1)

Country Status (5)

Citations (3)

Family Cites Families (1)

• 1980
  • 1980-04-16 DK DK161780A patent/DK145076C/da not_active IP Right Cessation
• 1981
  • 1981-04-15 EP EP81901154A patent/EP0049290B1/en not_active Expired
  • 1981-04-15 JP JP56501347A patent/JPH036056B2/ja not_active Expired - Lifetime
  • 1981-04-15 WO PCT/DK1981/000040 patent/WO1981003005A1/en not_active Ceased
  • 1981-12-09 NO NO814196A patent/NO153958C/no unknown

Patent Citations (3)

Also Published As

Similar Documents

Legal Events