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EP-4467325-B1 - MULTI-PURPOSE SEALING MODULE FOR PLASTIC FILM BASED BAGS

EP4467325B1EP 4467325 B1EP4467325 B1EP 4467325B1EP-4467325-B1

Inventors

  • Mistry, Hemang Rameshchandra
  • Pithava, Janak Keshavlal

Dates

Publication Date
20260513
Application Date
20231114

Claims (6)

  1. A multi-purpose sealing module (20) for a machine (10) to manufacture heat-sealed plastic film based bags and pouches, comprising a. a servo motor driven common drive shaft (30) in keyed connection with eccentric cams (40a, 40b) and eccentric cams (50a, 50b) such that eccentricity is equal and in opposite directions; b. crank arms (60a, 60b) connected to the eccentric cams (40a, 40b) though bearings (80a, 80b) and through bearings (120a, 120b) to linear guide rods (100a, 100b); c. the linear guide rods (100a, 100b) in connection with upper seal beam (140); d. crank arms (70a, 70b) connected to the eccentric cams (50a, 50b) though bearings (90a, 90b) and through bearings (130a, 130b) to Connecting Rods (110a, 110b); e. the Connecting Rods (110a, 110b) in rigid connection with lower seal beam (150); f. movement of the lower seal beam (150) guided by the linear guide rods (100a, 100b); and g. angular movement of the drive shaft (30) giving simultaneous linear movement in opposite directions to the upper seal beam (140) and the lower seal beam (150) controlling the gap between a sealing jaw connected to the upper seal beam (140) and a sealing jaw connected to the lower seal beam (150); and seal time and seal pressure of sealing of plastic film based bags and pouches; and angular movement of the drive shaft (30) controlled by a programmable controller; characterised in that the linear guide rods (100a, 100b) are in rigid connection with the upper seal beam (140).
  2. The multi-purpose sealing module (20) as claimed in claim 1 wherein the common drive shaft (30) is driven by pneumatic rotary actuators.
  3. The multi-purpose sealing module (20) as claimed in claim 1 wherein the common drive shaft (30) is connected with eccentric cams (40a, 40b) and eccentric cams (50a, 50b) using clamping bushes.
  4. A multi-purpose sealing module (220) for a machine (210) to manufacture heat-sealed plastic film based bags and pouches, comprising: a. a servo motor driven common drive shaft (230) in keyed connection with eccentric cams (240a, 240b) and eccentric cams (250a, 250b) such that eccentricity is equal and in opposite directions; b. crank arms (260a, 260b) connected to the eccentric cams (240a, 240b) though bearings (280a, 280b) and through bearings (320a, 320b) to linear guide rods (300a, 300b); c. the linear guide rods (300a, 300b) in connection with front seal beam (340); d. crank arms (270a, 270b) connected to the eccentric cams (250a, 250b) though bearings (290a, 290b) and through bearings (330a, 330b) to Connecting Rods (310a, 310b); e. the Connecting Rods (310a, 310b) in rigid connection with rear seal beam (350); f. movement of the rear seal beam (350) guided by the linear guide rods (300a, 300b); and g. angular movement of the drive shaft (230) giving simultaneous linear movement in opposite directions to the front seal beam (340) and the rear seal beam (350) controlling the gap between a sealing jaw connected to the front seal beam (340) and a sealing jaw connected to the rear seal beam (350); and seal time and seal pressure of sealing of plastic film based bags and pouches; and angular movement of the drive shaft (230) controlled by a programmable controller; characterised in that the linear guide rods (300a, 300b) are in rigid connection with the front seal beam (340).
  5. The multi-purpose sealing module (220) as claimed in claim 4 wherein the common drive shaft (230) is driven by pneumatic rotary actuators.
  6. The multi-purpose sealing module (220) as claimed in claim 4 wherein the common drive shaft (230) is connected with eccentric cams (240a, 240b) and eccentric cams (250a, 250b) using clamping bushes.

Description

FIELD OF THE INVENTION The current invention relates to high speed machines to manufacture heat-sealed plastic film based bags and pouches. The present invention more particularly relates to multi-purpose sealing modules for high speed machines for manufacturing heat-sealed plastic film based bags and pouches. PRIOR ART AND THE PROBLEM TO BE SOLVED Plastic converting and flexible packaging industries are mainly engaged with producing plastic bags and pouches that have light weight, good strength, durability, are cost-effective and environmentally friendly. Plastic bags and pouches are used for containing and transporting goods such as foods produce, powders, magazines, chemicals, waste, etc. Conventionally, plastic bags and pouches are made by heat-sealing, where two heated sealing jaws are brought in close proximity or contact with the plastic films to be joined that may be multi-structured or even laminated and pressing them in a controlled manner for certain time period. Depending on the sealing requirement, either both the sealing jaws have open-close movement or only one sealing jaw is moved and another sealing jaw remains fixed and act as seal base. Sealing jaw movement is conventionally achieved by pneumatic cylinder actuation; motorized ball screw movement; timing belt-pulley drive; or a variety of mechanical linkages. Plastic material has poor thermal conductivity. Therefore, for sealing to take place between two inside layers of plastic films, energy has to flow from the outer layers in contact with the sealing jaws to the inner layers where sealing occurs. If the process is not carried out precisely, it deteriorates or damages the appearance of the pouch/bag in the sealing area, producing bad pouches/bags. Pouches/bags with clear seal finish and leak proof sealing are the industry's requirements. US Patent No. 6,550,255 B1 discloses a method and apparatus for obtaining individual web sections from a web of sheet material. In the invention disclosed therein, pressure and possibly heat is applied by means of blocks to opposite faces of an end portion of each flattened bag length as it passes through a sealing station. The heater bars disclosed therein are mounted on lightly spring loaded mounting blocks. Deflection of springs does not remain consistent for a long period especially, after high speed use. As a result, the quality of the bags produced is compromised. Also, for different material of the sheet, mechanical adjustments have to be made to the apparatus. US Patent Application No. 2022/0242080 A1 discloses a bag making machine and bag making method wherein a heat-generating head of a sealing device is reciprocated via a link member and thermally fuses the multi-layer film. Such mechanism having a link member reciprocating the sealing device requires mechanical adjustments to be made to the machine for different material of the film. US Patent No. 4,753,629 discloses a thermoplastic film heat bonding apparatus wherein reciprocating motion of a heated seal bar is supported by a support member with a resilient coupling between the support member and the heated seal bar. The resilience of such couplings does not remain consistent for a long period especially, after high speed use. As a result, the quality of the bags produced is compromised. Also, for different material of the sheet, mechanical adjustments have to be made to the apparatus. EP 3 374 153 A1 discloses a bag-forming apparatus comprising a pair of opposed sealing bars positioned on opposite sides of a forming plane. Each sealing bar is mounted on a guide arm that extends from a first end, through the forming plane, to a second end. The guide arms are movably mounted to a frame, and a drive shaft is connected to the second end of each arm. Rotation of the shaft moves the sealing bars into and out of engagement with a web of bag-forming material traveling therebetween in the forming plane. The drive shaft can be translatable relative to the mounting frame to adjust a closure gap between the pair of opposed sealing bars. AT 502 740 A2 discloses a device for filling, closing and separating containers containing bulk material from a tubular structure of thermoweldable sheet arranged concentrically to a supply conduit for the bulk material, comprising means for controlled lowering of the tubular structure on the outside of the conduit, two welding bars provided with cutting means supported by respective movable slides on respective guides for sliding in a plane orthogonal to the axis of the conduit, below its end, and means for conferring said reciprocating slides in a reciprocal movement, comprising said means two parallel crazy trees orthogonal to the guides and linked to rotate together, each supporting at least one cam having a profile symmetrical with that of the cam supported by the other shaft, each slide comprising at least one cam follower slidable on the cam of the nearest tree. Hence, there is a need for a multi-purpose sealing