CN118475444A

CN118475444A - Cutter, filling machine and method for filling and sealing packages

Info

Publication number: CN118475444A
Application number: CN202280086958.XA
Authority: CN
Inventors: 戈兰·赫莫德森; 乌尔夫·莫斯贝里; 迈克尔·格尔贝里
Original assignee: Tetra Laval Holdings and Finance SA
Current assignee: Tetra Laval Holdings and Finance SA
Priority date: 2021-12-30
Filing date: 2022-12-14
Publication date: 2024-08-09
Also published as: EP4205925A1; WO2023126175A1

Abstract

A knife (200) for slitting a body of packaging material at a transverse sealing area of the body. The tool (100) comprises: a serrated edge (210) having a plurality of cutting teeth (211, 214) for slitting the packaging material to form a first cutting surface (112) and a second cutting surface (218) of the packaging material (101). The first blade surface (204) and the second blade surface (206) extend from respective sides of the serrated edge (210); and the serrated cutting edge (210) comprises kerf cutting teeth (212) arranged to cut a kerf (108) in the first cutting surface (112).

Description

Cutter, filling machine and method for filling and sealing packages

Technical Field

The present invention relates to packaging technology. More particularly, it relates to a knife for cutting open packaging material, a filling machine comprising such a knife and a method for filling and sealing packages.

Background

Reel-fed packaging machines are well known in the packaging field, in particular in the field of liquid food packaging. A well-known example in the field of liquid food packaging is the company rile (Tetra) Filling machines (also called packaging machines) were introduced to the market in the 40 s of the 20 th century. In short, these are now available in TetraA3 name receives a reel of cardboard-based packaging material in a machine. Once stopped on the filling machine, the web of packaging material is unwound from the reel. After sterilization by use of hydrogen peroxide or the like, the web is formed into a tube. The tube is filled with food (e.g., milk) via a product filling tube extending from above the tube to the interior while the tube is held upright. By continuously and transversely sealing and cutting into small pieces from the lower end of the tube, packages of filled food products can be formed at a surprising speed.

Over the years of use of reel-fed packaging machines, various knives have been used for severing packages. Today, it is known to use tools with serrated edges. It is also known to have an edge with a raised edge middle portion. By having this raised intermediate portion, the tube of packaging material is first cut at the intermediate portion of the tube, followed by cutting of the two peripheral ends of the tube. It is known to use serrated edges in combination with raised intermediate portions to achieve reliable cutting.

All knives used for cutting are not manufactured for completely severing the package. Cutters for providing perforation patterns are also known. By using such a tool, a plurality of packages connected to each other is provided, i.e. a string of packages can be formed. The consumer can then tear from the string, one by one, along the perforation pattern created between the packages by the knife.

While different knives are known for cutting a tube of packaging material to form individual packages, there is still a need to provide improved knives that impart better or additional functionality during the packaging process or to the package itself.

Disclosure of Invention

It is an object of the present invention to at least partially overcome one or more of the above limitations of the prior art. In particular, it is an object to provide a knife which helps to provide a package that is easy for the consumer to open, but which can still be produced in a cost-effective and food safe way in a reel-fed packaging machine. Another object is to provide a knife which allows the production of such packages and which can be installed in existing filling machines.

According to a first aspect, a knife for slitting a body of packaging material at a transverse sealing region of the body is provided. The cutter comprises: a serrated edge having a plurality of cutting teeth for slitting the packaging material, thereby forming a first cutting surface and a second cutting surface of the packaging material; first and second blade surfaces extending from respective sides of the serrated edge; and at least one attachment portion for securing the cutter to the cutting device. The serrated cutting edge comprises kerf cutting teeth arranged to kerf a kerf in the first cutting surface.

An advantage of having a slit cutting tooth enabling to provide a slit in the first cutting surface is that the slit facilitates the opening of the package by the consumer. More specifically, the cut provides a starting point for tearing the package. This provides cost effectiveness since the cut can be made at the same time as the two subsequent packages are separated, rather than in separate equipment. From an environmental point of view, the cutter has the advantage that an opening device with a low carbon footprint can be achieved, since the cut-out can form part of the opening device of the package without involving any plastic material.

The kerf cutting tooth may be longer than the cutting tooth as seen in the cutting direction of the tool. The kerf cutting tooth may be at least 25% longer than the cutting tooth. The kerf cutting tooth may be at least 1mm longer than the cutting tooth.

The kerf cutting tooth may comprise a first tooth surface which is flush with the first blade surface and which extends beyond the tip of an adjacent cutting tooth in the cutting direction of the tool.

By arranging the kerf cutting teeth in this manner, a sharp kerf can be formed in the first cutting surface. Furthermore, by arranging the cutters in this manner, the length difference between the kerf cutting teeth and the cutting teeth (i.e., the other teeth of the serrated edge) required to form the kerf is small.

The kerf cutting tooth may comprise a second tooth surface which is flush with the second blade surface and extends beyond the tip of an adjacent cutting tooth in the cutting direction of the tool.

The first tooth surface, which is flush with the first blade surface, may extend at least 1mm beyond the tips of adjacent cutting teeth in the cutting direction of the cutter.

The first tooth surface, which is flush with the first blade surface, may have a width D3 in a direction transverse to the cutting direction of the tool, which width D3 is at least 0.4mm.

The kerf cutting tooth may comprise a leading edge which is inclined with respect to the cutting direction of the tool by an angle alpha in the range of 80 deg. -100 deg..

The cutting tooth may be a single bevel, wherein the bevel is located on the same side as the first blade surface.

The cutting teeth may comprise respective leading edges which are inclined at an angle in the range 25 ° -65 ° relative to the cutting direction of the cutter.

All cutting teeth may have the same length or have a corresponding length that deviates by at most 10% from the average of the cutting tooth lengths.

The attachment portion may be arranged for securing the knife to the cutting device with the first blade surface facing upwards such that it faces the uppermost one of the first and second cutting surfaces of the packaging material.

According to a second aspect, a filling machine for filling and sealing packages is provided. The filling machine includes: a longitudinal sealing unit arranged to form a tube from a web of packaging material; a product filling tube arranged to fill the food product into the tube; and a cutting and sealing unit comprising a cutting device arranged to transversely seal and cut the tube to form individual packages filled with the food product. The cutting and sealing unit comprises a knife according to the first aspect.

The filling machine may further comprise a tube guiding unit arranged relative to the knife guiding tube such that the guide wire of the packaging material is aligned with the incision cutting tooth of the knife.

The advantage of having a tube guiding unit is that the tube can be guided such that the incision provided during cutting is aligned with a guide wire provided in the packaging material before cutting, e.g. in a converting plant producing the packaging material.

According to a third aspect, a method of filling and sealing a package is provided. The method includes forming a tube from a web of packaging material, filling the food product into the tube, and transversely sealing and cutting the tube to form individual packages filled with the food product. Cutting comprises cutting the tube with a cutter according to the first aspect.

The method may further comprise guiding the tube relative to the knife such that the guide wire of the packaging material is aligned with the kerf cutting teeth of the knife.

As mentioned above, an advantage over knife guiding tubes is that the tube can be guided such that the cut provided during cutting is aligned with a guide wire provided in the packaging material before cutting, e.g. in a converting plant producing the packaging material.

Other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

Drawings

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which

Fig. 1 is a perspective view of the upper part of the package.

Fig. 2 is a cross-sectional view of the transverse sealing unit.

Fig. 3 is a perspective view of the knife and tube prior to cutting.

Fig. 4 is a perspective view of the knife and tube of fig. 3 after cutting.

Fig. 5 is a perspective view of the tool.

Fig. 6 is a top view of the tool of fig. 5.

Fig. 7 is a bottom view of the knife of fig. 5.

Fig. 8 is an enlarged view of the kerf cutting tooth of the knife of fig. 5.

Fig. 9 is a cross-sectional view taken along line A-A of fig. 6, showing the kerf cutting tooth.

Fig. 10 is a cross-sectional view taken along line B-B of fig. 6, showing the cutting teeth.

Fig. 11 is a schematic view of a filling machine.

Fig. 12 is a flow chart illustrating a method for filling and sealing a package.

Detailed Description

Fig. 1 illustrates an upper portion of a package 100. The package 100 may be a paperboard package, i.e. a package made of a paperboard based packaging material 101.

As shown, the package 100 includes a top fin 102 and a body 104 in which the food product is contained. Although not shown, bottom fins may be provided at the opposite end of the package 100 in a similar manner. There is a transverse seal 106 in the top fin 102. The transverse seal 106 may be achieved in different ways. For example, by using so-called induction heating, an electric current can be induced in the packaging material 101, such that the plastic layer of the packaging material melts. By pressing the tubes horizontally together, the molten plastic layer of the packaging material 101 may be formed into a transverse seal 106.

Unlike known food packages, the package 100 shown in fig. 1 is provided with a cut-out 108. The benefit of having the cut-out 108 is that this may facilitate opening the package 100. In other words, the cutout 108 allows the top edge (also referred to as the first cutting surface 112) of the top fin 102 to be divided into two portions. This has the advantage that the slit 108 helps to tear the top fin 102 at the location where the slit 108 is located when a consumer grasps one portion of the top fin 102 with one hand and the other portion of the top fin 102 with the other hand and pulls the two portions apart. By providing the slit 108, the package 100 is opened more controllably. Furthermore, by providing the incision 108, an elderly person or other person with limited muscles may be able to open the package 100 without the need for a pair of scissors or other tools.

In addition, a guide wire 110 may be provided for the convenience of the consumer as a guide for tearing the package 100, i.e., tearing the top fin 102 and part of the body 104. The guide line may be a line that has been printed on the packaging material, or may be a perforation line, a crease line or a line formed of a plastic material. When the guide line 110 is a crease line or a semi-perforated line, it also acts as a line of weakness. The line of weakness may be provided by a plurality of perforations placed one after the other in the cardboard layer of the packaging material 101. In addition to the paperboard layer, the packaging material 101 may also comprise at least an inner plastic layer and an outer plastic layer, between which the paperboard layer is laminated.

When producing the package 100 shown in fig. 1, a transverse sealing unit, i.e. a cutting and sealing unit 809, can be used, as also shown in fig. 2 and also in fig. 11. As shown in fig. 11, a transverse sealing unit 809 may be placed downstream of the longitudinal sealing unit 804, in which longitudinal sealing unit 804 the web of packaging material 101 is folded into a tube and provided with a longitudinal seal to form the tube.

By using the transverse sealing unit 809, the top fin 102 and the bottom fin can be formed simultaneously. In the illustrated example, this is achieved by placing a heat sealing unit 502 (e.g., an inductor) on one side of the tube 201 of packaging material 101 (also referred to as the packaging material body) and an anvil 504 on the opposite side. The anvil 504 may be provided with two vertically spaced apart carts 506a, 506b. A space is provided between the two carts 506a, 506b for placing the cutting device 500 including the cutter 200. The knife 200 may be fed in a cutting direction C through a horizontal channel 510 of the anvil 504, through the tube 201 and into a groove 508 provided in the heat sealing unit 502. The cutting direction C is a direction transverse to the direction L in which the edge of the cutter 200 extends. When the cutter 200 has a serrated edge, the cutting direction C is a direction transverse to the direction L in which the serrated edge extends. The cutting direction may then also be the direction in which the cutting teeth 211, 214 of the serrated edge extend. By using knife 200, when tube 201 is sealed together in transverse sealing region 207, transverse sealing region 207 may be cut into two parts, forming top fin 102 of one package and bottom fin of the other package.

Although a transverse sealing unit is exemplified herein, other types of cutting and sealing units 809 may be used. Furthermore, although explained above with respect to induction heat sealing, other types of sealing techniques, such as ultrasonic sealing, may be used.

Separate devices may also be used to provide transverse sealing and cutting. If such a method is chosen, the cutting apparatus 500 comprising the knife 200 and the motor for moving it back and forth may be provided as a separate device downstream of the transverse sealing device comprising the heat sealing unit 502, the anvil 504 and the motor for moving both between the closed and the open state.

Fig. 3 shows a perspective view of the knife 200 and the tube 201 separated prior to cutting, i.e. prior to the knife 200 dividing the tube 201 in the transverse sealing region 207. The knife 200 can be seen as a cutting blade provided with a ridge 203 facing away from the tube 201 during cutting and a serrated edge 210 facing the tube 201 during cutting and extending in a longitudinal extension L perpendicular to the cutting direction C. During operation, i.e., when installed in a transverse sealing unit or other cutting device 500, the first blade surface 204 may face upward and the second blade surface 206 may face downward. To ensure that the tool 200 is securely fixed, attachment portions 208a, 208b (holes are exemplified herein) may be provided.

Serrated edge 210 has cutting teeth 211 and in order to be able to form kerfs 108 during cutting, kerf cutting teeth 212 are provided. As shown in more detail in fig. 3 and 8, the kerf cutting tooth 212 may be longer than the cutting tooth 211 as seen in the cutting direction C.

Fig. 4 shows another perspective view of the knife 200 separated from the tube 201 but after cutting. As shown, due to the kerf cutting teeth 212, the kerf 108 can be formed in the package 100. In addition, a second cutting surface 218, i.e., a bottom edge, is also formed. Although the package 100 is formed upside down in the illustrated example, the package may be formed upright.

By arranging the attachment portions 208a, 208b to interact with the cutting device 500, the knife 200 may be firmly mounted, so that the position of the incision 108 in the first cutting surface 112 may be controlled in detail. The attachment portions 208a, 208b, possibly in combination with the contour of the knife, may be arranged such that the knife 200 can only be mounted with the first blade surface 204 facing upwards, thereby reducing the risk of the slit 108 being erroneously disposed in the second cutting surface 218 (i.e. in the bottom fin of the package 100).

Fig. 5 shows the tool 200 in more detail. As shown, the kerf cutting teeth 212 may be longer than the cutting teeth 211, 214 of the serrated edge 210. The kerf cutting teeth 212 may be at least 25% longer than the cutting teeth 211, 214. The difference in length between the kerf cutting teeth 212 and the cutting teeth 211, 214 may be at least 1mm in absolute number.

As shown, the tool 200 may be single bevel. In other words, the cutting teeth 211, 214 may be a single bevel, with the bevel being located on the first blade surface 204.

The cutting teeth 211, 214 may have the same length, i.e. all teeth of the serrated edge 210 except for the kerf cutting teeth 212 may have the same length. If the lengths of the cutting teeth 211 are not equal, they may each differ by less than + -5% from the average length of the cutting teeth 211, 214.

Fig. 6 shows the knife 200 seen from above, with the first blade surface 204 facing upwards, i.e. in accordance with the arrangement of the knife in the transverse sealing unit 500 shown in fig. 2. On the other hand, fig. 7 shows the tool 200 seen from below, showing the second blade surface 206.

Figure 8 shows the kerf cutting tooth 212 and adjacent cutting teeth 211, 214 in further detail. The kerf cutting tooth 212 may include a first tooth surface 2121 that forms a portion of the first blade surface 204 or, in other words, that is flush with the first blade surface 204. Further, the first tooth surface 2121 may be arranged to extend beyond the tip 2111 of an adjacent cutting tooth 211 in the cutting direction C. The first tooth surface 2121 may extend at least 1mm beyond the tip 2111 of the adjacent cutting tooth 211.

The kerf cutting tooth 212 may also include a second tooth surface 2122 (see fig. 7 and 9), the second tooth surface 2122 forming part of the second blade surface 206 or, in other words, being flush with the second blade surface 206. As shown, cutting tooth 212 may have a length D1 from a base line BL of serrated edge 210 to a kerf cutting tooth tip line NL, and adjacent cutting teeth 211, 214 may have a length D2 from base line BL to an end line EL (i.e., cutting tooth tip line). As shown, the length D1 of the cutting teeth 212 may be greater than the length D2 of the cutting teeth 211, 214. Furthermore, as shown, all of the cutting teeth 211, 214 may have the same length D2.

Furthermore, the first tooth surface 2121 can have a width D3 in a direction L transverse to the cutting direction C, the width D3 being at least 0.4mm.

Fig. 9 shows a cross-sectional view along the line A-A shown in fig. 6. As shown, the leading edge 2123 of the notch cutting tooth 212 may not have a bevel. The leading edge 2123 may also be provided with a bevel, but with a bevel less than the bevel of the cutting teeth 211, 214 or the bevel on the second blade surface 206. The leading edge 2123 may be inclined at an angle α in the range of 80 ° to 100 ° relative to the cutting direction C.

Fig. 10 shows a cross-sectional view of a cutting tooth similar to cutting teeth 211, 214, as seen along line B-B of fig. 6.

As shown, the cutting teeth may include respective leading edges 2113 that are inclined at an angle β in the range of 25 ° -65 ° relative to the cutting direction C. The cutting teeth 211, 214 adjacent to the kerf cutting tooth 212 may be sloped in the same manner.

Fig. 11 shows a filling machine 800. A web 802 of packaging material 101 may be provided, which may be provided from a packaging material reel, for example. In the longitudinal sealing unit 804, the web 802 may be formed into a tube 201 by guiding the web 802 and also continuously providing a longitudinal seal, i.e. connecting together the two longitudinal edges of the web. By keeping the tube 201 upright, the food item 807 can be filled into the tube through the product filling tube 806. Starting from the longitudinal sealing unit 804, the tube 201 may be guided through a tube guiding unit 808 into a cutting and sealing device 809, as shown in more detail in fig. 2.

In addition to the cutting device 500, the heat sealing unit 502, and the anvil 504 shown in fig. 2, the cutting and sealing device 809 (which may also be referred to as a transverse sealing unit) may comprise one or more motors 810 arranged to move the heat sealing unit 502 and the anvil 504 towards each other and away from each other during production of the package 100. Prior to sealing, anvil 504 is moved in anvil direction D-a and heat sealing unit 502 is moved in sealing unit direction D-S opposite anvil direction D-a. Consistent with other examples described herein, package 100 is produced upside down, with first cutting surface 112 having cut 108 facing downward and second cutting surface 218 facing upward.

Fig. 12 is a flow chart illustrating a method 900 for filling and sealing package 100. In a first step 902, the tube 201 may be formed from a web of packaging material 101. In a second step 904, a food product 807 may be filled into the tube 201. In the third step 906 and the fourth step 908, the package 100 may be formed by transversely sealing the tube 201, and then cutting the tube 201 into the package 100. For cutting, the knife 200 described above may be used.

Optionally, in a fifth step 910, the tube 201 may be guided relative to the knife 200 such that the guide wire 110 of the packaging material 101 is aligned with the kerf cutting teeth 212 of the knife 200 such that the kerf 108 of the first cutting surface 112 is aligned with the guide wire 110.

From the foregoing description, it will be appreciated that while various embodiments of the invention have been described and shown, the invention is not limited thereto but may be otherwise embodied within the scope of the subject matter defined in the following claims.

Claims

1. A knife (200) for slitting a body (201) of packaging material (101) at a transverse sealing region (207) of the body (201), the knife (100) comprising:

-a serrated edge (210) having a plurality of cutting teeth (211, 214) for slitting the packaging material (101) to form a first cutting surface (112) and a second cutting surface (218) of the packaging material (101);

A first blade surface (204) and a second blade surface (206) extending from respective sides of the serrated edge (210); and

At least one attachment portion (208 a, 208 b) for securing the knife (200) to a cutting device (500), wherein

The serrated cutting edge (210) comprises kerf cutting teeth (212) arranged to cut a kerf (108) in the first cutting surface (112).

2. The knife (200) of claim 1, wherein the kerf cutting tooth (212) is longer than the cutting tooth (211).

3. The cutter (200) according to any one of the preceding claims, wherein the kerf cutting tooth (212) is at least 25% longer than the cutting tooth (211).

4. The cutter (200) according to any one of the preceding claims, wherein the kerf cutting tooth (212) is at least 1mm longer than the cutting tooth (211).

5. The cutter (200) according to any one of the preceding claims, wherein the kerf cutting tooth (212) comprises a first tooth surface (2121), the first tooth surface (2121) being flush with the first blade surface (204) and extending beyond a tip (2111) of an adjacent cutting tooth (211) in the cutting direction (C) of the cutter (200).

6. The knife (200) of claim 5, wherein the kerf cutting tooth (212) comprises a second tooth surface (2122), the second tooth surface (2122) being flush with the second blade surface (206) and extending beyond the tip (2111) of an adjacent cutting tooth (211) in the cutting direction (C) of the knife (200).

7. The cutter (200) according to claim 5 or 6, wherein the first tooth surface (2121) flush with the first blade surface (204) extends beyond the tip (2111) of an adjacent cutting tooth (211) by at least 1mm in the cutting direction (C) of the cutter (200).

8. The tool (200) according to any one of claims 5-7, wherein the first tooth surface (2121) flush with the first blade surface (204) has a width (D3) of at least 0.4mm in a direction (L) transverse to the cutting direction (C) of the tool (200).

9. The tool (200) according to any one of the preceding claims, wherein the cutting tooth (211) is a single bevel, wherein the bevel is located on the same side as the first blade surface (204).

10. The tool (200) according to any one of the preceding claims, wherein all cutting teeth (211) have the same length (D2) or have a respective length (D2) that deviates at most 10% from the average of the lengths of the cutting teeth (211).

11. The knife (200) according to any one of the preceding claims, wherein the attachment portion (208 a,208 b) is arranged for securing the knife (200) to a cutting device (500) with the first blade surface (204) upwards such that it faces an uppermost cutting surface (112) of the first (112) and second (218) cutting surfaces of the packaging material (101).

12. A filling machine (800) for filling and sealing packages (100), the filling machine (800) comprising:

A longitudinal sealing unit (804) arranged to form a tube (201) from a web of packaging material (101);

A product filling tube (806) arranged to fill a food product (807) into the tube (201); and

-A cutting and sealing unit (809) comprising a cutting device (500) arranged to seal and cut the tube (201) laterally to form individual packages (100) filled with the food product (807); wherein the cutting and sealing unit (809) comprises:

The tool (200) according to any one of the preceding claims.

13. The filling machine of claim 12, comprising:

-a tube guiding unit (808) arranged to guide the tube (101) relative to the knife (200) such that a guide wire (110) of the packaging material (201) is aligned with the kerf cutting teeth (212) of the knife (200).

14. A method (900) for filling and sealing a package (100), the method comprising:

Forming (902) a tube (201) from a web of packaging material (101);

Filling (904) a food product (807) into the tube (201); and

Transversely sealing (906) and cutting (908) the tube (201) to form individual packages (100) filled with the food item (807); wherein the cutting (908) comprises cutting the tube (201) with a knife (200) according to any one of claims 1-13.

15. The method as claimed in claim 14, comprising:

-guiding (910) the tube (201) relative to the knife (200) such that a guide wire (110) of the packaging material (101) is aligned with the kerf-cutting teeth (212) of the knife (200).