GB703756A - Improvements in or relating to the manufacture of bags from thermoplastic sheet material - Google Patents

Improvements in or relating to the manufacture of bags from thermoplastic sheet material

Info

Publication number
GB703756A
GB703756A GB27546/50A GB2754650A GB703756A GB 703756 A GB703756 A GB 703756A GB 27546/50 A GB27546/50 A GB 27546/50A GB 2754650 A GB2754650 A GB 2754650A GB 703756 A GB703756 A GB 703756A
Authority
GB
United Kingdom
Prior art keywords
webs
transverse
bags
along
heating
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
GB27546/50A
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.)
Cellophane SA France
Original Assignee
Cellophane SA France
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 Cellophane SA France filed Critical Cellophane SA France
Publication of GB703756A publication Critical patent/GB703756A/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
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B29C66/432—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • 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
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/78—Means for handling the parts to be joined, e.g. for making containers or hollow articles, e.g. means for handling sheets, plates, web-like materials, tubular articles, hollow articles or elements to be joined therewith; Means for discharging the joined articles from the joining apparatus
    • B29C65/7841—Holding or clamping means for handling purposes
    • B29C65/7847—Holding or clamping means for handling purposes using vacuum to hold at least 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
    • B29C66/003—Protecting areas of the parts to be joined from overheating
    • 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
    • B29C66/4312—Joining the articles to themselves for making flat seams in tubular or hollow articles, e.g. transversal seams
    • 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
    • B29C66/8182—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 thermal insulating constructional aspects
    • B29C66/81821—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 thermal insulating constructional aspects of 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
    • B29C66/80—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
    • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
    • B29C66/8341—Roller, cylinder or drum types; Band or belt types; Ball types
    • B29C66/83411—Roller, cylinder or drum types
    • 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
    • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
    • B29C66/8341—Roller, cylinder or drum types; Band or belt types; Ball types
    • B29C66/83411—Roller, cylinder or drum types
    • B29C66/83413—Roller, cylinder or drum types cooperating rollers, cylinders or drums
    • 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
    • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
    • B29C66/8341—Roller, cylinder or drum types; Band or belt types; Ball types
    • B29C66/83411—Roller, cylinder or drum types
    • B29C66/83415—Roller, cylinder or drum types the contact angle between said rollers, cylinders or drums and said parts to be joined being a non-zero angle
    • 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
    • B29C66/834—General aspects of machine operations or constructions and parts thereof characterised by the movement of the joining or pressing tools moving with the parts to be joined
    • B29C66/8351—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws
    • B29C66/83511—Jaws mounted on rollers, cylinders, drums, bands, belts or chains; Flying jaws jaws mounted on rollers, cylinders or drums
    • 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
    • B29C66/84—Specific machine types or machines suitable for specific applications
    • B29C66/851—Bag or container making machines
    • B29C66/8511—Bag making machines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B70/00—Making flexible containers, e.g. envelopes or bags
    • 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
    • B29C2795/00—Printing on articles made from plastics or substances in a plastic state
    • B29C2795/002—Printing on articles made from plastics or substances in a plastic state before shaping
    • 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
    • B29C66/70—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
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B2155/00—Flexible containers made from webs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B2155/00—Flexible containers made from webs
    • B31B2155/002—Flexible containers made from webs by joining superimposed webs, e.g. with separate bottom webs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B2160/00—Shape of flexible containers
    • B31B2160/10—Shape of flexible containers rectangular and flat, i.e. without structural provision for thickness of contents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B—MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
    • B31B70/00—Making flexible containers, e.g. envelopes or bags
    • B31B70/14—Cutting, e.g. perforating, punching, slitting or trimming
    • B31B70/16—Cutting webs
    • B31B70/18—Cutting webs longitudinally

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Making Paper Articles (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)

Abstract

703,756. Making thermoplastic bags. CELLOPHANE SOC. ANON. Nov. 10, 1950 [Nov. 22, 1949] No. 27546/50. Class 94 (2) [Also. in Group VIII] In a process for the manufacture of bags from a thermoplastic material, or other material coated with a thermoplastic, two webs of the material, of a width which is a multiple of the depth or height of the bags to be made. are superimposed edge to edge and united by heat applied along the coincident edges 1, along one or more intermediate longitudinal lines 2, and also along transverse lines 3, the individual bags being obtained by cutting along the centres of the lines 2 and, as shown in Fig. 1, along transverse lines z, z' adjacent to the, transverse welds 3. Alternatively the webs anay be cut along a longitudinally welded line m, m<SP>1</SP>, Fig. 4, and along a line v, v<SP>1</SP> midway between the welded longitudinal edges and the weld line m, m<SP>1</SP> the transverse cuts then being made along the centre lines t, t' of the transverse welds, so that the mouths of the bags thus produced are at the longitudinal cut v, v<SP>1</SP>. - Instead of the cuts v, v<SP>1</SP> a succession of transverse cuts intermediate adjacent pairs of transverse cuts t, t' may be made. The heat-sealing and cutting- apparatus may be arranged following a printing machine which prints designs &c. on one of the thermoplastic webs, after which the webs are superposed and passed over a metal roller covered with a material of low heat conductivity, e.g. fabric or vulcanized fibre, and under narrow heating-rollers which may have a smooth, knurled, or engraved rim, and are formed with a central groove which provides a narrow unwelded stripe. A series of successively arranged heating rollers may be mounted adjacent to the periphery of the under roller to ensure satisfactory longitudinal welds. The webs are next guided around another roller mounted below a heating-bar which bears upon the webs transversely and may be arranged to travel a short distance in contact with the webs. For high speed operation a series of transverse heating bars 20, Fig. 3, may be-mounted between a pair of endless chains 19, the spacing of the bars being equal to the spacing of the bags, and their movement such that they accompany the web while forming the weld. The longitudinal cutting of the webs and subsequent transverse cutting is effected by passing them around rollers associated with slitters and a cutter operating in known manner. Alternatively the several rollers associated with the welding and cutting operations may be replaced by. a single drum of large diameter with the. requisite operating devices mounted.adjacent to its periphery. In a modification, Fig. 6, the transverse welds are formed after the cutting. The longitudinal welds and cuts are effected by devices 21, 15 respectively, and transverse cuts by a rotary knife 23. Simultaneously with the latter cutting operation, the leading edges of the length thus cut are gripped between a pair of heated jaws such as 25, 25' mounted in the periphery of a rotary drum 26. Pairs of similar jaws 27, 28 are spaced equally around the drum. The jaw 25 is fixed, while the co-operating jaw 25<SP>1</SP> is carried by a lever 39-40 pivoted to the drum and operable by a fixed cam 38 in opposition to a tensioned spring 42. Heat-insulating bars 31 confine the heating to the gripped edges of the bags, which are welded while being carried around by the drum until released upon a conveyer 30. The conveyer may comprise an endless felt band 32 moving over a. perforated casing 33 connected to a suction fan. The ends of the heating jaws may be cut away to form narrow non-heating gaps opposite the centres of the longitudinal welds to prevent re-uniting of the longitudinally severed portions of the webs.
GB27546/50A 1949-11-22 1950-11-10 Improvements in or relating to the manufacture of bags from thermoplastic sheet material Expired GB703756A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR703756X 1949-11-22

Publications (1)

Publication Number Publication Date
GB703756A true GB703756A (en) 1954-02-10

Family

ID=9062897

Family Applications (1)

Application Number Title Priority Date Filing Date
GB27546/50A Expired GB703756A (en) 1949-11-22 1950-11-10 Improvements in or relating to the manufacture of bags from thermoplastic sheet material

Country Status (1)

Country Link
GB (1) GB703756A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3224915A (en) * 1962-08-13 1965-12-21 Cavitron Ultrasonics Inc Method of joining thermoplastic sheet material by ultrasonic vibrations
US3272682A (en) * 1962-08-13 1966-09-13 Cavitron Ultrasonics Inc Apparatus for joining thermoplastic sheet material with ultrasonic rotary vibrators
US4497679A (en) * 1981-10-13 1985-02-05 Hathaway Charles T Method of forming plastic envelopes
WO1998028123A1 (en) * 1996-12-20 1998-07-02 Kimberly-Clark Worldwide, Inc. Method and apparatus for full width ultrasonic bonding
EP1346818A3 (en) * 1996-12-20 2007-01-17 Kimberly-Clark Worldwide, Inc. Method and apparatus for full width ultrasonic bonding

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3224915A (en) * 1962-08-13 1965-12-21 Cavitron Ultrasonics Inc Method of joining thermoplastic sheet material by ultrasonic vibrations
US3272682A (en) * 1962-08-13 1966-09-13 Cavitron Ultrasonics Inc Apparatus for joining thermoplastic sheet material with ultrasonic rotary vibrators
US4497679A (en) * 1981-10-13 1985-02-05 Hathaway Charles T Method of forming plastic envelopes
WO1998028123A1 (en) * 1996-12-20 1998-07-02 Kimberly-Clark Worldwide, Inc. Method and apparatus for full width ultrasonic bonding
US5817199A (en) * 1996-12-20 1998-10-06 Kimberly-Clark Worldwide, Inc. Methods and apparatus for a full width ultrasonic bonding device
EP1346818A3 (en) * 1996-12-20 2007-01-17 Kimberly-Clark Worldwide, Inc. Method and apparatus for full width ultrasonic bonding

Similar Documents

Publication Publication Date Title
CA1161679A (en) Method and apparatus for producing plastics bags
US2688356A (en) Multiple unit laminating apparatus
US3581457A (en) Wrapping method and apparatus
US3257256A (en) Device for welding and cutting thermoplastic webs
US3748205A (en) Method and apparatus for making a profile bag structure
US3967767A (en) Device for severing and feeding flaccid wrapping sheets
GB703756A (en) Improvements in or relating to the manufacture of bags from thermoplastic sheet material
US2229121A (en) Method and apparatus for operating on sheet material
US2423187A (en) Bag making machine
GB1600114A (en) Apparatus for the manufacture of bags
US3765989A (en) Apparatus for crosslaying web materials
US2465044A (en) Apparatus for making bags
GB1054644A (en)
GB1147466A (en) Method and apparatus for producing bags from tubular film
US3007835A (en) Method of forming edge-united laminar articles and apparatus therefor
US3233527A (en) Bag making machine
US3693319A (en) Wrapping individual slices of food
GB1321587A (en) Stacking apparatus for flattened thermoplastic bags
GB1578568A (en) Apparatus for perforating synthetic plastics film
US2909877A (en) Container wrapping assemblage
GB978075A (en) Mechanism for seaming or welding thermoplastic web material
US1753967A (en) Veneer trimmer
US3863549A (en) Gripper-transfer device for plastic bags
US2640540A (en) Cutting shoe for bagmaking machines
GB837420A (en) Apparatus for forming seams in sheet material