Heat sealing jaw with asymmetric teeth
By designing an asymmetrical peak and valley sealing gripper structure, the sealing strength of the packaging film is enhanced, solving the problem of insufficient sealing area in existing technologies and achieving a more robust packaging seal.
Patent Information
- Application Number
- CN202610072022.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2019-10-03
- Filing Date
- 2020-09-08
- Publication Date
- 2026-02-24
AI Technical Summary
In existing technologies, the sealing strength of packaging films is insufficient, especially during the heat sealing process. The design of the grippers cannot effectively enhance the mechanical interlocking between films, resulting in insufficient sealing area.
A pair of mating sealing jaws were designed, wherein the sealing surface of each jaw has an asymmetrical peak and valley structure with different peak angles, and the jaws close intermittently to form a seal, thereby enhancing the interlocking effect between the membranes.
The asymmetrical peak and valley design increases the sealing area and strength, improves the mechanical interlocking effect of the packaging film, and forms a more robust seal.
Smart Images
Figure CN121553484A_ABST
Abstract
Description
[0001] Divisional application statement
[0002] This application is a divisional application of Chinese invention patent application filed on September 8, 2020, with application number 2020800697989 and invention title "Thermo-sealing gripper with asymmetric teeth". Technical Field
[0003] This disclosure relates to food packaging and forming equipment, and in particular to sealing grippers for forming such packaging. Background Technology
[0004] Many goods are packaged on forming, filling, and sealing packaging machines. Packaging bags are formed on these machines from rolls of materials such as polymers and metal foil films, or combinations thereof. The bags are formed, filled, sealed, and then disconnected from the advancing flow of bags being formed on the packaging machine.
[0005] Typically, one or more layers of film forming the inner side of the bag are designed by the film manufacturer to soften and flow when subjected to heat and pressure. The side seals and transverse seals of the forming, filling, and sealing bag packaging machine heat and pressurize the front and rear films together to adhere the corresponding films to each other. Typically, during heating and pressurization through the sealing section, the inner layers of the packaging film soften and flow, causing them to adhere to each other to seal the front and rear films together to form the bag.
[0006] To enhance the seal between the front and rear membranes, the sealing surfaces of the sealing strip (whether side or transverse) are typically knurled with a "serrated" or "square wave" pattern. This stretches the membranes about the area where they are sealed together. This stretching increases the sealing surface area between the membranes and, to some extent, mechanically interlocks the front and rear membranes.
[0007] The most common packaging films are heat-sealable polymer compositions. Several variables exist during the heat-sealing process, but the most important are the pressure applied by the grippers, the residence time (i.e., the duration of pressure application), and the sealing temperature. The sealing temperature is typically determined by the packaging material. However, the applied pressure and residence time are parameters that the operator can control. It should be understood that there is a relationship between the applied pressure and residence time, and thus, controlling these two is generally desirable to enable the production of a larger quantity of packages. Summary of the Invention
[0008] According to one aspect of this disclosure, a pair of mating sealing jaws for forming a seal between opposing heat-sealable surfaces includes a first jaw and a second jaw, the second jaw having a sealing surface complementary to the sealing surface of the first jaw. The jaws intermittently close to form a seal as opposing heat-sealable materials traverse the pair of mating sealing jaws.
[0009] The first gripper has a sealing surface comprising at least two peaks (ridges) separated by valleys (grooves). Each peak comprises a first face and a second face. An imaginary line bisects the valley, defining a first angle between the imaginary line and the first face, and a second angle between the imaginary line and the second face. The first angle differs from the second angle. In some cases, the difference between the first angle and the second angle is in the range of about 10° to about 30°.
[0010] In one embodiment, the pair of grippers includes complementary cutting grooves. In some embodiments where cutting grooves are present, the sealing surface of the first gripper on a first side of the cutting groove has a profile that is a mirror image of the sealing surface on a second side of the cutting groove.
[0011] In some cases, the first surface of each peak defines a leading surface, while the second surface of each peak defines a following surface. When a tool groove is provided, on the first side of the tool groove, the first angle will be greater than the second angle, while on the second side of the tool groove, the first angle will be less than the second angle. Because the second gripper has a sealing surface complementary to the sealing surface of the first gripper, the first angle will be less than the second angle on the first side of the tool groove, while on the second side of the tool groove, the first angle will be greater than the second angle.
[0012] Other aspects, embodiments, and features of the invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings. The drawings are not intended to be drawn to scale. In the drawings, each identical or substantially similar component shown in the various figures is generally represented by a number or symbol. For clarity, not every component is labeled in every figure. Not every component of every embodiment of the invention is shown where the description is not essential for enabling those skilled in the art to understand the invention.
[0013] The invention extends to kits and apparatuses of methods, systems, components, and parts that are substantially as described herein and / or as shown with reference to the accompanying drawings.
[0014] This invention extends to any novel aspects or features described and / or illustrated herein. Furthermore, apparatus aspects can be applied to method aspects, and vice versa. Moreover, any, some, and / or all features of one aspect can be applied in any suitable combination to any, some, and / or all features of any other aspect.
[0015] It should also be understood that specific combinations of the various features described and defined in any aspect of the invention may be implemented and / or provided and / or used independently. Attached Figure Description
[0016] The following description is taken in conjunction with the accompanying drawings, all of which are given by way of non-limiting example, which can be used to understand how the described methods and systems can be embodied.
[0017] Figure 1 It is a perspective view of a prior art filling device.
[0018] Figure 2 This is an isometric view of an embodiment of a pair of mating sealing jaws.
[0019] Figure 3 yes Figure 2 The image shows a side view of a pair of mating sealing jaws, with the two jaws placed together in a relatively parallel alignment, and depicts an embodiment of peaks and valleys.
[0020] Figure 4 It is a side view of another embodiment of a pair of mating sealing jaws, wherein the two jaws are placed together in a relative, parallel alignment, and another embodiment of peaks and valleys is depicted.
[0021] Figure 5 It shows Figure 3 The enlarged portion of the sealing gripper that cooperates with it.
[0022] Figure 6 It shows Figure 4 The enlarged portion of the sealing gripper that cooperates with it. Detailed Implementation
[0023] Figure 1 A typical vertical forming, filling, and sealing packaging machine is shown. This type of machine forms bags from film stored on rollers (not shown) and pulled along a film path extending through a set of tensioners and passing through a forming collar that allows the film to wrap around the outer surface of the forming unit. The film path is a set of predetermined positions along which the film travels; for example, the path the film takes through the machine when manipulating the film from a generally planar shape factor to a filled bag. The film is pulled along the length of the forming unit by a set of pull belts while a vertical sealer seals the longitudinal edges of the film together to form a film tube. A transverse seal is formed in the film tube by mating sealing jaws, described below, located downstream of the pull belts and on the opposite side of the film path.
[0024] In operation, a partially formed bag is filled with product, which is first weighed, then passed through a funnel, then through a forming device, and then deposited into the partially formed bag. The partially formed bag, now filled with product, is sealed at the upstream end by mating sealing jaws and removed from the membrane tube to form a bag filled with food. In one embodiment, the mating sealing jaws are configured to receive a cutter or knife that separates the downstream bag from the upstream membrane tube when a lateral seal is formed, or shortly after the lateral seal is formed.
[0025] Now go to Figure 2This diagram illustrates a pair of mating heat-sealing jaws for forming a seal between opposing heat-sealable surfaces. More specifically, a first sealing jaw 10 is disposed on a first side of a film path F, and a second sealing jaw 12 is disposed on a second (opposite) side of the film path and positioned opposite the first sealing jaw 10. The first jaw 10 has a first sealing surface 14, while the second jaw 12 has a second sealing surface 16, the first and second sealing surfaces being complementary to each other. Each jaw has corresponding and complementary slots 50, 52 configured to receive a blade (not shown) to separate the formed package from a subsequently formed package.
[0026] Now for reference Figure 3 An embodiment of a pair of mating heat-sealing jaws is shown. The structure of each jaw will be generally described with reference to the first jaw 10, as it should be understood that the second jaw 12 has a complementary structure. As described above, the first jaw 10 has a first sealing surface 14, which is provided with at least two peaks 20 (also referred to as ridges or lands) separated by valleys 26 (also referred to as grooves). Although Figure 3 The diagram shows the first gripper 10 having two peaks 20 (and the second gripper 12 having three peaks 120), but it should be understood that the sealing surface can be provided with a greater number of peaks. For example, Figure 4 Another embodiment of the mating sealing jaws is shown, wherein the first jaw 10 has four peaks 20 (and the second jaw 12 has five peaks 120). It should be understood that by providing a greater number of peaks and valleys compared to jaws with fewer peaks and valleys, a larger area of the package will be sealed, and therefore a greater amount of film will be used to form the package.
[0027] Back Figure 3 Each peak 20 of the first gripper 10 has a first surface 30 and a second surface 34. In this respect, it should be understood that when opposing heat-sealable surfaces approach and cross a pair of mating heat-sealable grippers in the film direction F, the first surface 30 can be considered as the leading surface 32 and the second surface can be considered as the following surface 34.
[0028] Similarly, each peak 120 of the second jaw 12 has a first face 130 and a second face 134. In this respect, it should be understood that when the opposing heat-sealing surfaces approach and traverse a pair of mating heat-sealing jaws, the first face 130 can be considered as the leading face 132 and the second face can be considered as the following face 134.
[0029] The first gripper 10 is provided with a first cutting groove 50, and the second gripper 12 is provided with an opposing second cutting groove 52. Both the first cutting groove 50 and the second cutting groove 52 are configured to receive a knife (not shown) that will separate the completed package from the package to be completed. Typically, and as... Figure 3As shown, the first cutting groove 50 and the second cutting groove 52 are respectively located approximately at the middle of the first gripper and the second gripper. Therefore, referring to the first gripper 10, two peaks 20 are provided on the first side 54 of the first cutting groove 50 (the leading portion of the first gripper 10 (in the membrane travel direction F)) and two peaks 20 are provided on the second side 56 of the first cutting groove 50 (the following portion of the first gripper 10 (in the membrane travel direction)).
[0030] Similarly, referring to the second gripper 12, three peaks 120 are provided on the first side 154 (the leading portion of the second gripper 12 (in the membrane travel direction F)) of the second groove 52, and three peaks 120 are provided on the second side 156 (the following portion of the second gripper 12 (in the membrane travel direction F)) of the second groove 52. Because the first gripper 10 and the second gripper 12 are complementary, it should be understood that when the first gripper and the second gripper move toward each other, the peaks 20 on the first sealing surface 14 approach the valleys 126 on the second sealing surface 16, and vice versa.
[0031] Now go to Figure 5 , showed Figure 3 The enlarged portions of the first and second sealing jaws are shown. It should be understood that the top of each peak 20, 120 is flat (22, 122) to provide a trapezoidal shape for each peak 20. Similarly, each valley 26, 126 is flat (27, 127). Alternatively, and Figure 5 The best way to show, Figure 5 yes Figure 4 The enlarged portions of the first and second sealing jaws shown in the diagram have curved tops (24, 124) for each peak 20, 120. Similarly, each valley 26, 126 is curved (29, 129).
[0032] As previously described, each peak 20, 120 has a first surface 30, 130 (leading surface 32, 132) and a second surface 34, 134 (following surface 36, 136). Imaginary lines 40, 140 that bisect valleys 26, 126 (i.e., divide valley 26 into two equal parts) define a first angle A and a second angle B, whereby the first angle A is the angle generated by the imaginary lines 40, 140 and the first surface 30, 130, and the second angle B is the angle generated by the imaginary lines 40, 140 and the second surface 34, 134.
[0033] The first surfaces 30 and 130 and the second surfaces 34 and 134 are formed such that the first angle A is different from the second angle B. In some cases, the difference between the first angle A and the second angle B is in the range of about 10° to about 30°, and in some cases the difference is about 20°.
[0034] It should be understood that the peaks and valleys on the first sides 54 and 154 of the cutting grooves 50 and 52 form the bottom of the package, while the peaks and valleys on the second sides 56 and 156 of the cutting grooves 50 and 52 form the top of the previous package. Therefore, it is advantageous if the shape profiles of the peaks 20 and 120 and the valleys 26 and 126 on the first sides 54 and 154 of the cutting grooves 50 and 52 are mirror images of the peaks 20 and 120 and the valleys 26 and 126 on the second sides 56 and 156 of the cutting grooves 50 and 52.
[0035] In this respect, in one embodiment and referring to the first gripper 10, on the first side 54 of the cutter groove 50, angle A is greater than angle B. In this case, angle A is in the range of about 25° to about 60°, or about 35° to about 55°, or about 40° to about 50°, and in some cases about 45°. Angle B is in the range of about 15° to about 35°, or about 20° to about 30°, or about 25°.
[0036] When the shape profile of the peaks and valleys on the second side 56 of the first cutter groove 50 is a mirror image of the shape profile of the peaks and valleys on the first side 54 of the first cutter groove 50, angle A is smaller than angle B. In this case, angle A ranges from about 15° to about 35°, or from about 20° to about 30°, or about 25°. Angle B ranges from about 25° to about 60°, or from about 35° to about 55°, or from about 40° to about 50°, and in some cases is about 45°.
[0037] As previously described, the second gripper 12 is complementary to the first gripper. Therefore, on the first side 154 of the second cutter groove 52, angle A is smaller than angle B. In this case, angle A ranges from about 15° to about 35°, or from about 20° to about 30°, or about 25°. Angle B ranges from about 25° to about 60°, or from about 35° to about 55°, or from about 40° to about 50°, and in some cases is about 45°.
[0038] When the shape profile of the peaks and valleys on the second side 156 of the second cutter groove 52 is a mirror image of the shape profile of the peaks and valleys on the first side 154 of the second cutter groove 52, angle A is greater than angle B. In this case, angle A is in the range of about 25° to about 60°, or about 35° to about 55°, or about 40° to about 50°, and in some cases about 45°. Angle B is in the range of about 15° to about 35°, or about 20° to about 30°, or about 25°.
[0039] With the aforementioned configuration of peaks and valleys, particularly when the defined angles A and B are asymmetrical, it should be understood that each peak 20, 120 (bore or ridge) will be "eccentrically" positioned within its opposite and complementary valley 26, 126. This arrangement is believed to generate higher tension in areas where angle A or angle B is smaller, and consequently, a stronger seal. Those skilled in the art will understand that, in this configuration, the stronger portion of the seal will originate from the leading edge inside the packaging.
[0040] While the concepts of this disclosure are capable of various modifications and alternatives, specific exemplary embodiments of this disclosure have been shown by way of example in the accompanying drawings. However, it should be understood that this disclosure is not intended to limit the concepts to the specific forms disclosed; the invention is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
[0041] In general, a pair of mating sealing jaws for forming a seal between opposing heat-sealing surfaces is described. The mating sealing jaws include a first jaw having a sealing surface comprising at least two peaks separated by valleys. Each peak includes a first face and a second face such that an imaginary line bisects the valley defines a first angle between the imaginary line and the first face and a second angle between the imaginary line and the second face, such that the first angle differs from the second angle. A second jaw is provided having a sealing surface complementary to the sealing surface of the first jaw.
[0042] Various aspects of the invention are also set forth in the following numbered clauses, wherein:
[0043] 1. A pair of mating sealing jaws, said pair of mating sealing jaws for forming a seal between opposing heat-sealable surfaces, said pair of mating sealing jaws comprising:
[0044] A first gripper, the first gripper having a sealing surface, the sealing surface including at least two peaks separated by valleys, wherein each peak includes a first face and a second face, and wherein an imaginary line bisecting the valley defines a first angle between the imaginary line and the first face, and defines a second angle between the imaginary line and the second face, such that the first angle is different from the second angle; and,
[0045] The second gripper has a sealing surface that is complementary to the sealing surface of the first gripper.
[0046] 2. The sealing gripper as described in Clause 1, wherein the dimensional difference between the first angle and the second angle is in the range of about 10° to about 30°.
[0047] 3. The sealing jaws according to Clause 1 or Clause 2, wherein the first jaw includes a cutting groove, and the second jaw includes a cutting groove opposite to the cutting groove of the first jaw.
[0048] 4. The sealing jaw according to any one of the preceding clauses, wherein the sealing surface of the first jaw on a first side of the cutting groove of the first jaw has a profile, the profile being a mirror image of the sealing surface on a second side of the cutting groove of the first jaw.
[0049] 5. The sealing jaw according to any one of the preceding clauses, comprising at least two peaks separated by valleys on the sealing surface of the first jaw on the first side of the cutting groove of the first jaw and at least two peaks separated by valleys on the second side of the cutting groove of the first jaw.
[0050] 6. The sealing jaws according to any one of the preceding clauses, wherein, when the opposing heat-sealing surfaces traverse the pair of mating sealing jaws, the first face of each peak on the first jaw defines a leading face, and the second face of each peak on the first jaw defines a following face.
[0051] 7. The sealing gripper according to any one of the preceding clauses, wherein on the first side of the tool groove, the first angle is greater than the second angle, and on the second side of the tool groove, the first angle is less than the second angle.
[0052] 8. In a pair of mating sealing jaws for forming a seal between opposing heat-sealing surfaces, wherein each jaw has at least two peaks separated by valleys, the improvement is to include an imaginary line bisecting the valleys defining a first angle between the imaginary line and a first facet of the peaks, and defining a second angle between the imaginary line and a second facet of the adjacent peaks, such that the first angle is different from the second angle.
Claims
1. A vertical forming, filling, and sealing packaging machine comprising heat-sealing jaws for forming a seal between opposing heat-sealable surfaces, the heat-sealling jaws comprising: (a) A first gripper disposed on a first side of the membrane path, the first gripper comprising: (i) A first cutting groove disposed approximately at the middle of the first gripper, defining a first side of the first gripper disposed on one side of the first cutting groove and a second side of the first gripper disposed on the other side of the first cutting groove, and (ii) The sealing surface of the first gripper includes at least two peaks separated by valleys on each of the first and second sides of the first gripper, wherein - Each peak includes a leading surface and a following surface, such that the leading and following surfaces of adjacent peaks create valleys between them. - An imaginary line bisects each valley defines a first angle (A) between the imaginary line and the leading surface, and defines a second angle (B) between the imaginary line and the following surface, such that the profile of the sealing surface of the first gripper on a first side of the first gripper is a mirror image of the profile of the sealing surface on a second side of the first gripper. - On the first side of the first gripper, the first angle (A) is greater than the second angle (B), and on the second side of the first gripper, the first angle (A) is less than the second angle (B); and, (b) A second gripper having a sealing surface complementary to the sealing surface of the first gripper, such that during the heat sealing process, each peak will enter a relative and complementary valley at an eccentric position.
2. The vertical forming, filling, and sealing packaging machine according to claim 1, wherein, The second gripper is disposed on the opposite side of the membrane path, and the second gripper includes: (a) A second cutting groove disposed approximately at the middle of the second jaw, defining a first side of the second jaw disposed on one side of the second cutting groove and a second side of the second jaw disposed on the other side of the second cutting groove, and (b) The sealing surface of the second jaw, which includes at least two peaks separated by valleys on each of the first and second sides of the second jaw, wherein (i) Each peak includes a leading surface and a following surface, such that the leading and following surfaces of adjacent peaks create valleys between them. (ii) An imaginary line bisecting each valley defines a first angle (A) between the imaginary line and the leading surface, and defines a second angle (B) between the imaginary line and the following surface, such that the profile of the sealing surface of the second jaw on the first side of the second jaw is a mirror image of the profile of the sealing surface on the second side of the second jaw, and (iii) On the first side of the second gripper, the first angle (A) is greater than the second angle (B), and on the second side of the second gripper, the first angle (A) is less than the second angle (B).
3. The vertical forming, filling, and sealing packaging machine according to claim 1 or 2, wherein, The dimensional difference between the first angle (A) and the second angle (B) is in the range of about 10° to about 30°.
4. The vertical forming, filling, and sealing packaging machine according to claim 2, wherein, The second cutting groove is opposite to the first cutting groove of the first gripper.
5. The vertical forming, filling, and sealing packaging machine according to claim 1, wherein, On the first side of the first gripper, the first angle (A) is between 25° and 60°, and on the second side of the first gripper, the first angle (A) is between 15° and 35°.
6. The vertical forming, filling, and sealing packaging machine according to claim 5, wherein, On the first side of the first gripper, the second angle (B) is between 15° and 35°, and on the second side of the first gripper, the second angle (B) is between 25° and 60°.
7. The vertical forming, filling, and sealing packaging machine according to claim 5, wherein, On the first side of the second gripper, the first angle (A) is between 15° and 35°, and on the second side of the second gripper, the first angle (A) is between 25° and 60°.
8. The vertical forming, filling, and sealing packaging machine according to claim 7, wherein, On the first side of the second gripper, the second angle (B) is between 25° and 60°, and on the second side of the second gripper, the second angle (B) is between 15° and 35°.
9. The vertical forming, filling, and sealing packaging machine according to claim 6, wherein, On the first side of the second gripper, the first angle (A) is between 15° and 35°, and on the second side of the second gripper, the first angle (A) is between 25° and 60°.
10. The vertical forming, filling, and sealing packaging machine according to claim 9, wherein, On the first side of the second gripper, the second angle (B) is between 25° and 60°, and on the second side of the second gripper, the second angle (B) is between 15° and 35°.