Packaging sealing tool

Abstract

: A packaging sealing tool, packaging sealing jaw and packaging machine for providing improved sealing performance. The packaging sealing tool, sealing jaw and packaging machine are suitable for providing a robust and hermetic seal with paper based packaging. The packaging sealing tool comprises a first sealing jaw comprising a first sealing profile and a second sealing jaw comprising a second sealing profile. The first and second sealing jaws are configured to move between a disengaged arrangement, in which the first and second sealing profiles are separated, and an engaged arrangement, in which the first and second sealing profiles engage for sealing a packaging. The first sealing jaw comprises an elastomer strip and the elastomer strip forms part of the first sealing profile. The method of operating a packaging sealing tool, comprises: installing an elastomer strip into a sealing profile of a sealing jaw, using the sealing jaw to seal packaging, removing the elastomer strip from the sealing jaw without disassembling the sealing jaw and replacing the removed elastomer strip with a second elastomer strip without disassembling the sealing jaw.

Description

[0001] Packaging Sealing Tool

[0002] FIELD

[0003] The present invention relates to a packaging sealing tool.

[0004] BACKGROUND

[0005] There is a growing need for sustainable packaging solutions. In order to meet this demand, paper based packaging is seeing increased attention and use across a range of food and other consumer good sectors. Paper based packaging is used in a range of formats, including bags and pouches. Such packaging will often require sheets of material to be closed and sealed in some arrangement - for example at the top and bottom.

[0006] The secure closure and sealing of flexible packaging, such as bags and pouches used for food and other consumer goods, is crucial for maintaining product freshness, preventing contamination, and ensuring consumer safety. There is a challenge in providing robust and hermetic seals for packaging, and in particular paper based packaging, in a reliable manner. This is particularly challenging at transitions between different numbers of layers of packaging - e.g. at a “triple point” where a seal is provided across a step from two to four layers of material. Existing devices and methods are unable to guarantee a hermetic seal across such transitions, in particular without damaging the material of the seal itselL

[0007] Traditional packaging sealing methods and tools include heat sealing and crimp sealing. Heat sealing involves applying heat and pressure to localised areas of the packaging film, creating a melted or bonded closure. While heat sealing can be effective, precise temperature control is necessary to avoid scorching or weakening the film. Excessive heat will often damage the packaging material; this is particularly the case for paper based packaging. Heat sealing is also not appropriate for all material types.

[0008] Crimp sealing relies on the deformation of the packaging material to create a tight bond. Crimp sealing provides unreliable sealing characteristics, particularly with variations in film thickness or bag filling levels. Additionally, crimp sealing techniques often require high force application - which may potentially damage delicate packaging materials such as paper based packaging material and may also lead to inconsistent or inadequate sealing.

[0009] Packaging machines often have jaws for engaging the packaging and providing the seal. Jaws in current packaging sealing machines are designed to provide seals in metallic or plastic based materials. Their geometries are therefore designed for these materials. Paper based packaging materials have very different material properties and jaws suitable for use with metallic or plastic packaging are typically unsuitable for paper based packaging, often damaging the packaging material or failing to provide a hermetic seal. There therefore exists a desire to provide a packaging sealing tool that mitigates at least one problem with existing packaging sealing tools and provides a robust and hermetic seal for paper based packaging in a reliable manner.

[0010] SUMMARY OF INVENTION

[0011] According to the disclosure is a packaging sealing tool. The packaging sealing tool comprises a first sealing jaw comprising a first sealing profile and a second sealing jaw comprising a second sealing profile. The first and second sealing jaws are configured to move between a disengaged arrangement, in which the first and second sealing profiles are separated, and an engaged arrangement, in which the first and second sealing profiles engage for sealing a packaging. The first sealing jaw comprises an elastomer strip. The elastomer strip forms part of the first sealing profile.

[0012] The packaging sealing tool provides improved sealing characteristics, in particular for paper based packaging. The sealing tool is able to provide a seal up to 100% tight, while reducing damage to the packaging. The first and second sealing jaws other than the elastomer strip may be made of metal. The use of an elastomer strip improves the pressure distribution over the sealing zone, improving the quality of the seal.

[0013] The packaging sealing tool may be for installation in a packaging machine and may be configured to receive material, e.g. film, between the sealing jaws. In order to provide the seal, heat and pressure may be applied to the packaging located between the sealing jaws in order to bond a heat seal layer of the packaging. The packaging sealing tool may be a paper based packaging sealing tool. The sealing tool provides an improved seal with paper based packaging while minimising heat and physical damage to the packaging. Such paper based packaging may comprise a film including a number of layers, wherein the majority of the film thickness is comprised of paper. Other layers may include a metallic layer, coating layer and sealing layer, for example.

[0014] The first and second sealing jaws may be configured to oppose each other and move between the disengaged and engaged arrangements, perpendicular to the sealing profiles. A separation is provided between the sealing profiles when in the disengaged arrangement, such that material (e.g. film layers) to be sealed can be located between the jaws. In the engaged arrangement, the jaws move together such that the sealing profiles engage to provide a seal between the film layers. In the engaged arrangement, the first and second sealing profiles engage to provide the seal.

[0015] The elastomer strip improves the sealing performance of the sealing tool by providing a robust and homogeneous seal while minimising physical and heat damage to the packaging.

[0016] The elastomer strip may form only part of the first sealing profile. The elastomer strip may comprise between 10 and 40% or 20 and 30% of the sealing profile (e.g. my surface area or width), for example.

[0017] The elastomer strip may have a round cross-section. Alternatively, the elastomer strip may be prismatic with a triangular, square, rectangular or otherwise polygonal crosssection.

[0018] The elastomer strip may have a diameter of between 1 mm and 4mm, or 2mm and 3mm, for example. The elastomer strip may have a diameter of about 2.5mm.

[0019] The elastomer strip may be made of any one, or a combination of, the following materials: rubber, silicone, neoprene, fluorocarbon rubber or elastomer.

[0020] The elastomer strip may have a density between: 1 .1 and 2.5 g / cm3, 1 .5 and 2.4 g / cm3or 2.0 to 2.3 g / cm3. The elastomer strip may have a thermal resistance of between 180 to 310°C.

[0021] The elastomer strip may have a compression set (ISO 815 Type B - e.g. ISO 815- 1 :2019) <20% - 24h at 175°C.

[0022] The elastomer strip may have a thermal conductivity of less than or equal to 0.3 W / m / K

[0023] The elastomer strip having these material properties may provide a particularly strong seal while maximising usable lifetime of the elastomer strip.

[0024] The elastomer strip may be food grade. That is, the elastomer strip may be suitable for coming into contact with food safely. The elastomer strip may meet the requirements of EC1935 / 2004 food contact materials (FCM) regulation in Europe or FDA 21 CFR 177.2600 in the USA.

[0025] The elastomer strip may have a hardness, e.g. a shore hardness, between 60A - 90A, 70A - 80A, or 73A - 77A. The elastomer strip may have a hardness of 75A. The hardness may be measured using a shore durometer according to ASTM D2240 type A as of July 23, 2021 , ISO 7619-1 Shore A ou DIN ISO 48-4 (Hardness shore A).

[0026] The elastomer strip may be food grade; and / or have a shore hardness between 70A - 80A as measured using a shore durometer according to ASTM D2240 type A as of July 23, 2021 ; and / or be made out of silicone or fluorocarbon elastomer or rubber.

[0027] The first sealing jaw may be configured such that the elastomer strip is replaceable without disassembling the first sealing jaw.

[0028] In this way, the packaging sealing tool has improved up-time. That is, time required for maintenance and replacement of the elastomer seal is greatly reduced, increasing overall packaging system efficiency.

[0029] In use, the elastomer strip may become damaged or worn. In order to replace the elastomer strip, the packaging machine must be shut down. Being able to replace the elastomer strip without disassembling the first sealing jaw greatly reduces the amount of time it takes to replace the elastomer strip; this in turn increases machine uptime and improves efficiency. The amount of downtime may be reduced by a factor of 20, 30 or more than 30.

[0030] The first sealing profile may comprise a pair of opposing flanges, between which a chamber is defined for receiving the elastomer strip.

[0031] The flanges and chamber may be configured to receive and support the elastomer strip during use. The chamber may have substantially the same dimensions, e.g. diameter, as the elastomer strip. The chamber may be accessible from the first sealing profile, thus negating the need to disassemble the first sealing jaw to replace the elastomer strip. The opposing flanges may be configured to define a reduced-diameter entrance to the chamber, such that the elastomer strip must be deformed in order to enter the chamber. The flanges may therefore hold the elastomer strip in the chamber and prevent the elastomer strip from unintentionally leaving the chamber during normal use. Instead, a user may need to activity pull the elastomer strip (thus deforming it) to remove it from the chamber.

[0032] The first and second sealing profiles may be configured to define a clearance between the sealing profiles (or between parts thereof) when in the engaged arrangement. The clearance may be a spacing between the profiles and it may reduce or eliminate damage to the packaging being sealed.

[0033] The first and second sealing profiles may be configured such that, in the engaged arrangement, a clearance between the elastomer strip and the second sealing profile is less than the clearance between the rest of the first sealing profile and the second sealing profile.

[0034] The clearance between the elastomer strip and the second sealing profile, in the engaged arrangement, may be zero. That is, there may be contact.

[0035] The first and second sealing profiles may be configured such that, in the engaged arrangement, the only contact between the first sealing profile and the second sealing profile is between the elastomer strip and the second sealing profile.

[0036] Naturally, discussion relating to contact between the elastomer strip and the second sealing profile refers to an arrangement in which no packaging is present between the sealing jaws and is referred to herein in order to describe the geometry of the sealing jaws. As such, the “engaged arrangement” discussed herein may refer to an engaged arrangement in which no packaging is present, e.g. for illustrative purposes.

[0037] The elastomer strip may be responsible for providing the tightest seal location in the packaging. That is, the first sealing profile may be configured such that the elastomer strip is comes into contact with the second sealing profile before any other part of the first sealing profile, as the sealing jaws move from the disengaged arrangement towards the engaged arrangement.

[0038] The elastomer strip may be configured to define a seal point between the first and second sealing profiles. The seal point may be the location of minimum clearance between the first sealing profile and the second sealing profile, for sealing packaging located therebetween.

[0039] The clearance defined between the first sealing profile other than the elastomer strip and the second sealing profile, in the engaged arrangement, may be between 0.2 and 0.5mm, 0.25 and 0.4mm, or 0.3 and 0.35mm. The clearance may be around 0.32mm. These clearances may vary depending on the material thickness of the packaging. The listed clearances may be suitable for material with a thickness of between 60 to 100 microns, for example.

[0040] Avoiding contact between the first sealing profile and second sealing profile - other than by the elastomer strip - minimises damage to the packaging. This is particularly true where the first and second sealing profiles (other than the elastomer strip) are made of metal, e.g. stainless steel.

[0041] In the engaged arrangement, the elastomer strip may be configured to oppose a recess of the second sealing profile. The elastomer strip may be configured to define a seal point between the elastomer strip and a flank or flank edge of the recess. A seal point may be defined as the location of minimum clearance between the first sealing profile and the second sealing profile, for sealing packaging located therebetween.

[0042] The recess opposing the elastomer strip may have two flanks and a base. The elastomer strip may contact the two flanks (or the edges of said flanks) in the engaged arrangement. This contact may provide the seal points, at which location the packaging is sealed most tightly. The recess opposing the elastomer strip may have substantially flat flanks (and optionally a flat base). This arrangement may provide a particularly tight seal.

[0043] Each of the first and second sealing profiles may define a length and a width. The first and second sealing profiles may define a plurality of teeth and recesses. The plurality of teeth and recesses may be configured to engage when the first and second sealing jaws are in the engaged arrangement. The teeth and recesses may be defined across the width and extend along the length of the respective sealing profile. The elastomer strip may extend along the length of the first sealing profile.

[0044] The length may be arranged in the plane and perpendicular to the feed direction of packaging passing between the sealing jaws during use. The width direction may be parallel to the feed direction through the sealing jaws. The width of the first and / or second sealing profile may be around 10mm.

[0045] The first and second sealing profiles may define a plurality of intermeshing teeth and recesses, configured to provide the seal.

[0046] The teeth of the first sealing profile may have rounded tips.

[0047] The teeth and recesses of the second sealing profile may define a substantially squarewave profile. The teeth and recesses (e.g. tips, flanks and roots) of the second sealing profile may have substantially flat surfaces.

[0048] The second sealing profile may have tapered teeth.

[0049] The use of rounded teeth on the first sealing profile and teeth with substantially flat tips, sides and roots on the second sealing profile may allow a robust seal to be provided (e.g. between the elastomer strip and the second sealing profile), but minimise damage to the packaging (e.g. between the rest of the first sealing profile and the second sealing profile).

[0050] The flanks of the teeth / recesses of the second sealing profile may define an angle therebetween of between 10 and 30 degrees, 15 and 25 degrees or 20 and 25 degrees. The flanks of the teeth / recesses of the second sealing profile may define an angle of 22 degrees. The teeth / recesses of the second sealing profile may comprise rounded edges and corners.

[0051] The elastomer strip may be located adjacent a tooth of the first sealing profile. The tooth may be configured to oppose a recess of the second sealing profile in the engaged arrangement. The first sealing jaw and second sealing jaw may be configured such that a clearance is defined between the tooth of the first sealing profile and the second sealing profile when the first and second sealing jaws are in the engaged arrangement such that there is no contact between the tooth of the first sealing profile and the second sealing profile.

[0052] The elastomer strip may be located between two teeth of the first sealing profile. The first sealing profile may comprise two teeth with the elastomer strip located therebetween. The second sealing profile may comprise four teeth and three recesses defined therebetween. Three recesses of the second sealing profile may be arranged to oppose two teeth and the elastomer strip of the first sealing profile in the engaged arrangement.

[0053] A tooth of one of the first sealing profile and second sealing profile and an opposing recess on the other of the first sealing profile and second sealing profile may be configured such that a cavity is defined between a tip of the tooth and the opposing recess when the first and second sealing jaws are in the engaged arrangement.

[0054] Such a cavity may be defined between each tooth and opposing cavity pair.

[0055] The cavity may be a hollow space located between a tip of a tooth of one of the first and second sealing profile and the root of a recess of the other of the first and second sealing profile. The presence of the cavity minimises damage to the seal in the event that particles (e.g. of foodstuffs) are located within the region of the packaging to be sealed. The cavity may provide a space within the seal region in which particles can be located without damaging the packaging or seal integrity.

[0056] The cavity may be an area of increased clearance between the first and second sealing profiles - e.g. defining a larger gap than is otherwise present between the first and second sealing profiles in the engaged arrangement. The cavity may define a space two, three, four, five or more than five times larger than the clearance otherwise provided between the first and second sealing profiles.

[0057] Further according to the disclosure is a packaging sealing jaw comprising a first sealing profile configured to engage a second sealing profile of a second packaging sealing jaw, for sealing a packaging; and an elastomer strip; wherein the elastomer strip is configured to form part of the first sealing profile.

[0058] The packaging sealing jaw may be according to the first sealing jaw described herein.

[0059] Further according to the disclosure is a packaging machine comprising a packaging sealing tool as described herein or a packaging sealing jaw as described herein.

[0060] Further according to the disclosure is a method of operating a packaging sealing tool, comprising: installing an elastomer strip into a sealing profile of a sealing jaw; using the sealing jaw to seal packaging; removing the elastomer strip from the sealing jaw without disassembling the sealing jaw; and replacing the removed elastomer strip with a second elastomer strip without disassembling the sealing jaw.

[0061] The method of operating a packaging sealing tool may comprise operating the packaging machine described herein, the packaging sealing tool described herein or the packaging sealing jaw described herein.

[0062] BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 is a perspective view a packaging machine including a packaging sealing tool;

[0064] Figure 2 is of a package, specifically a pillow bag;

[0065] Figure 3A is a partial view of a pillow bag, showing the seal;

[0066] Figure 3B is a partial view of Figure 3A;

[0067] Figure 3C is a schematic cross-section of Figure 3B;

[0068] Figures 4A and 4B are perspective views of a first and second sealing jaw, respectively; Figure 5 is of a packaging sealing tool in a disengaged arrangement;

[0069] Figure 6 is of the packaging sealing tool of Figure 6, in an engaged arrangement;

[0070] Figure 7 is of the packaging sealing tool of Figure 5, with the elastomer strip removed;

[0071] Figure 8 is a partial view of Figure 6; and

[0072] Figure 9 is a cross-section of a second packaging sealing tool.

[0073] DETAILED DESCRIPTION OF DRAWINGS

[0074] Figure 1 shows a packaging machine 10. The machine 10 is configured to form and fill a package 20, in this case a pillow bag, as shown in more detail in Figure 2. The packaging machine 10 receives film from a film roll 12 and product to be fed into the packaging at a product in-feed 14. The film passes along a film path 16 and is fed through the machine by a film feeder 18. A vertical sealing device 22 seals a side of the packaging 20. The end seal 26 of the package 20 is formed by a packaging sealing tool 30 comprising a pair of sealing jaws. The seal is provided, in this example, by the application of a combination of pressure and heat. Once sealed, the package 20 is discharged at a machine discharge.

[0075] Figure 2 shows a package 20, specifically a pillow bag. The pillow bag 20 includes a vertical side seal 24 along the side of a package 20 and an end seal 26 along an end of the package 20.

[0076] Figure 3A is a view of a part 28 of a pillow bag such as that shown in Figure 2. The partial view is of the end seal 26. It can be seen that the end seal 26 has a corrugated form, provided by the sealing tool’s 30 pair of sealing jaws (discussed in more detail with respect to Figure 5).

[0077] Figure 3B is a partial view of area 32 of Figure 3A, and Figure 3C is a schematic crosssection of Figure 3B along line A-A. Figures 3B and 3C show the intersection of the side seal 24 and end seal 26. This is often referred to as the “triple point” seal. It is located at the intersection of three pieces of material. It is a particular challenge to achieve a complete and robust seal at this location without damaging the film material. In prior art examples, it is common for an incomplete seal to be provided at-at least one of a first interface 34, second interface 36 or third interface 38 - most often the first interface 34.

[0078] As shown schematically in Figure 3C, the packaging machine 10 described herein provides a complete and robust seal at all three locations. One factor in achieving this is the application of a more uniform sealing force across the triple point seal, perpendicular to the surface of the film, as shown by arrows 40. The inclusion of the elastomer strip provides this improved force distribution.

[0079] The end seal 28 is provided by the packaging sealing tool 30, which comprises a pair of sealing jaws. The packaging sealing tool 30 is shown in more detail in Figures 4A to 8. Figures 4A and 4B are perspective views of a first sealing jaw 42 and second sealing jaw 44 respectively. Figures 5 through 7 are cross-sectional views of the packaging sealing tool. Figure 8 is an enlarged view of part of the first sealing jaw 42. The below description refers collectively to Figures 4A to 8.

[0080] The packaging sealing tool 30 comprises a first sealing jaw 42 and a second sealing jaw 44. The first sealing jaw 42 has a first sealing profile 46. The second sealing jaw 44 has a second sealing profile 48. The first and second sealing jaws 42, 44 (including the majority of the first and second sealing profiles 46, 48) are typically made of metal, for example stainless steel.

[0081] The first and second sealing profiles 46, 48 in the present case are surfaces between which a seal is provided. The first sealing jaw 42 and second sealing jaw 44 are configured to move between a disengaged arrangement, as shown in Figure 5 in which the first and second sealing profiles are separated, and an engaged arrangement as shown in Figure 6. In the disengaged arrangement, material to be sealed (e.g. films) can be received between the sealing profiles 46, 48. In the engaged arrangement, the first and second sealing profiles 46, 48 engage for sealing packaging.

[0082] The packaging sealing tool 30 comprising the sealing jaws 42, 44 is configured to be installed as part of a packaging machine 10, for example as describe with reference to Figure 1. The packaging machine 10 is configured to support the sealing jaws 42, 44 and move them between a disengaged and engaged arrangement as film is fed into and through the sealing jaws 42, 44. In order to connect to the rest of the packaging machine 10, the first and second sealing jaws 42, 44 comprise mechanical connectors which will not be discussed here. Hole 50 is configured to receive a guiding screw, for example to assist with positioning of the jaw. Connector 51 is configured to interface with a heat tube for heating the sealing jaws 42, 44.

[0083] The first sealing jaw 42 comprises an elastomer strip 52. The elastomer strip 52 forms part of the first sealing profile 46. In the shown packaging tool 30, the elastomer strip 52 has a circular cross-section. In other examples other cross-sections may be used.

[0084] The elastomer strip 52 is replaceable. The elastomer strip 52 can be readily removed from the first sealing profile 46 without dissembling or otherwise modifying or interfering with the first sealing jaw 42. The elastomer strip 52 can be readily removed simply by pulling it out of the first sealing profile 46. This allows a user to easily and quickly replace the elastomer strip 52, for example if it becomes damaged or worn. It also allows a user to replace the elastomer strip 52 in the event that an elastomer strip 52 with different physical properties is required, for example to seal a different type of package. The ease and speed with which the elastomer seal 52 can be replaced minimises downtime, which is critical for the efficient operation of a packaging machine 10.

[0085] In Figure 7, the first sealing jaw 42 is shown with the elastomer strip 52 removed. It can be seen that first sealing profile 46 comprises a chamber 54 for receiving the elastomer strip. The chamber 54 is defined between two flanges 56, 58. The two flanges 56, 58 cooperate to define an entrance to the chamber 54. The entrance has a reduced width compared to the internal diameter of the chamber 54 (i.e. in the width direction of the first sealing profile 46). This reduced width provides a gripping effect on the elastomer strip 52, whereby the elastomer strip 52 is gripped by the flanges 56, 58 once the elastomer strip 52 is located within the chamber 54. The elastomer strip 52 is thus held within the chamber 54 and a force needs to be exerted on the elastomer strip 52 to deform it to remove it from the chamber 54 - this means that it does not fall out during normal use.

[0086] The elastomer strip 52 of the present example has a circular cross section, in this case with a diameter of 2.5mm. This example of the elastomer strip is made of a fluorocarbon elastomer - a fluorocarbon-based elastomer. In other examples the elastomer strip may be made of silicone. The elastomer strip is certified as being food grade. The elastomer strip in the present example has a shore hardness between 70A - 80A as measured using a shore durometer (e.g. according to ASTM D2240 type A as of July 23, 2021 ). The elastomer strip 52 forms part of the first sealing profile 46. The first sealing profile 46 opposes the second sealing profile 48 on the second sealing jaw 44. The first and second sealing profiles 46, 48 define a length L and width W. The width extends in a direction parallel to the direction in which film is fed between the first and second sealing jaws 42, 44. The length extends in the place of packaging passing between the jaws 42, 44, transverse to the direction in which film is fed between the first and second sealing jaws 42, 44. The width W of the first and second sealing profile 46, 48 is between 8 - 12mm. For example 10mm. Typical sealing jaws have sealing profiles with a width of 14mm. In the present example, the width is reduced by way of a chamfered section. The reduced width increases the seal pressure and reduces the material consumption.

[0087] The first sealing profile 46 and second sealing profile 48 are complementary in shape. Broadly speaking, in the present example, the first and second sealing profiles 46, 48 define undulating profiles. The undulating profiles include teeth and recesses arranged across the width, extending along the length, of the sealing profiles 46, 48. The first and second sealing jaws 42, 44 are configured such that the teeth of the first sealing profile 46 oppose (and are aligned with, for example) recesses of the second sealing profile 48 when the first and second sealing jaws 42, 44 are in the engaged arrangement. As such, the first and second sealing profiles 46, 48 interlace in the engaged arrangement. The elastomer strip 52 of the example of Figures 4A to 8 essentially serves as a tooth of the first sealing profile 46.

[0088] In the present example, the first sealing profile 46 comprises two teeth 60 (and the elastomer strip 52). The teeth 60 are rounded and they protrude from a substantially flat surface. As such, the first sealing profile 46 of this example includes two rounded teeth 60 and substantially flat roots (i.e. flat bottomed recesses) 62 adjacent the teeth 60. The elastomer strip 52 services as a tooth and so has such recesses 62 on either side. The elastomer strip 52 is arranged between two teeth 60. In some examples, a sealing profile may comprise one, three, four or more than four such teeth.

[0089] In the present example, the second sealing profile 48 comprises a plurality of teeth - here four teeth 46. The teeth 64 comprise substantially flat tips. The teeth 64 are configured to oppose the recesses 62 of the first sealing profile 46 when in the engaged arrangement. In between the teeth 64 are recesses 66. The recesses 66 have a substantially flat bottom, or root. The recesses 66 are configured to oppose the teeth 60 and elastomer strip 52 of the first sealing profile 46 when in the engaged arrangement.

[0090] The second sealing profile 48 defines a substantially square-wave profile. The flanks of the teeth 64 and recesses 66 of the second sealing profile 48 in the present example are angled (e.g. with respect to the direction of engagement between the first and second sealing profiles). The teeth 64 are therefore tapered. The taper angle of the present example is 22 degrees. In other words, the angle of each flank is 11 degrees to the perpendicular, as shown in Figure 8. In other examples, the taper angle may be anywhere between 10 and 35 degrees, for example.

[0091] In this packaging sealing tool 30, the amplitude of the second sealing profile 48 (i.e. peak to trough height of the teeth 64 and recesses 66) is larger than that of the first sealing profile 46. A cavity 70 is defined between the tip of a (or each) tooth 60 of the first sealing profile 46 and the opposing recess 66 when the first and second sealing jaws 42, 44 are in the engaged arrangement. This cavity 70 reduces damage to the packaging seal during use - for example if contamination or particles are present in the sealing area. In other packaging sealing tools, a cavity may be defined between the tip or tips of the second sealing profile 48 and the recesses of the first sealing profile 46.

[0092] In the engaged arrangement, with packaging located between the sealing jaws 42, 44, a clearance may be defined between the first and second sealing profiles 46, 48. The presence of a clearance reduces damage to the packaging seal. The clearance between the elastomer strip 52 and the second sealing profile 48 is less than the clearance between the rest of the first sealing profile 46 and the second sealing profile 48. That is, the smallest gap between the first and second sealing profiles 46, 48 is defined by the elastomer strip 52 - the elastomer strip 52 is closer to the second sealing profile 48 than the rest of the first sealing profile 46. This provides a very robust seal while also minimising damage to the packaging.

[0093] It may be that the first and second sealing profiles 46, 48 are configured such that the elastomer strip 52 contacts the second sealing profile 48 in the engaged arrangement. In this case, the elastomer strip 52 is the only part of the first sealing profile 46 that contacts the second sealing profile 48. Where present, the clearance between the elastomer strip 52 and the second sealing profile 48 may be between 0.1 and 0.2mm, for example 0.14mm. The clearance between the rest of the first sealing profile 46 and second sealing profile 48 - e.g. between the recesses 62 of the first sealing profile 46 and the teeth 64 of the second sealing profile - may be between 0.3 and 0.4mm, e.g. 0.32mm.

[0094] The location of closest approach between the first and second sealing profiles 46, 48 is referred to herein as the seal point 72. It is the location where the best seal is provided. The seal point 72 of the present example is located between the elastomer strip 52 and the second sealing profile 48 (regardless of whether there is contact or not). More specifically, a seal point 72 is provided on either side of the elastomer strip 52 - between the elastomer strip 52 and the flanks 68 or edges of the flanks 68 (of an opposing recess) of the second sealing profile 48.

[0095] Figure 9 is a cross-section of a second example of a packaging sealing tool 130. There are a lot of similarities between the tool 130 of Figure 9 and that described with reference to Figures 4A to 8. Only the differences will be discussed here. Corresponding reference numerals are used in Figure 9 as those for the previous example, albeit incremented by 100.

[0096] In the packaging sealing tool 130 of Figure 9, two elastomer strips 152 are provided. The two elastomer strips 152 are located towards either end of the first sealing profile 146 in the width dimension. In addition to having two elastomer strips 152, the packaging sealing tool 130 of Figure 9 includes more teeth and recesses than that of Figure 5.

[0097] The present invention has been described above purely by way of example. Modifications in detail may be made to the present invention within the scope of the claims as appended hereto. Furthermore, features from one example may be combined with an alternative example unless such a combination is explicitly precluded.

Claims

1. CLAIMS:1 . A packaging sealing tool comprising: a first sealing jaw comprising a first sealing profile and a second sealing jaw comprising a second sealing profile; wherein the first and second sealing jaws are configured to move between a disengaged arrangement, in which the first and second sealing profiles are separated, and an engaged arrangement, in which the first and second sealing profiles engage for sealing a packaging; wherein the first sealing jaw comprises an elastomer strip; and the elastomer strip forms part of the first sealing profile.

2. The packaging sealing tool of claim 1 , wherein the first sealing jaw is configured such that the elastomer strip is replaceable without disassembling the first sealing jaw.

3. The packaging sealing tool of claim 1 or claim 2, wherein the first sealing profile comprises a pair of opposing flanges, between which a chamber is defined for receiving the elastomer strip.

4. The packaging sealing tool of any of the preceding claims, wherein the first and second sealing profiles are configured such that, in the engaged arrangement, a clearance between the elastomer strip and the second sealing profile is less than a clearance between the rest of the first sealing profile and the second sealing profile.

5. The packaging sealing tool of any of the preceding claims, wherein the first and second sealing profiles are configured such that, in the engaged arrangement, the only contact between the first sealing profile and the second sealing profile is between the elastomer strip and the second sealing profile.

6. The packaging sealing tool of any of the preceding claims, wherein, in the engaged arrangement, the elastomer strip is configured to oppose a recess of the second sealing profile and define a seal point between the elastomer strip and a flank or flank edge of the recess; wherein a seal point is defined as the location of minimum clearance between the first sealing profile and the second sealing profile in the engaged arrangement, for sealing packaging located therebetween.

7. The packaging sealing tool of any of the preceding claims, wherein each of the first and second sealing profiles defines a length and a width; and the first and second sealing profiles define a plurality of teeth and recesses configured to engage when the first and second sealing jaws are in the engaged arrangement; wherein the teeth and recesses are defined across the width and extend along the length of the respective sealing profile; and the elastomer strip extends along the length of the first sealing profile.

8. The packaging sealing tool of claim 7, wherein: the teeth of the first sealing profile have rounded tips; and the teeth and recesses of the second sealing profile define a substantially squarewave profile with tapered teeth.

9. The packaging sealing tool of any of the preceding claims, wherein the elastomer strip is located adjacent a tooth of the first sealing profile; the tooth is configured to oppose a recess of the second sealing profile in the engaged arrangement; and the first sealing jaw and second sealing jaw are configured such that a clearance is defined between the tooth of the first sealing profile and the second sealing profile when the first and second sealing jaws are in the engaged arrangement such that there is no contact between the tooth of the first sealing profile and the second sealing profile.

10. The packaging sealing tool of any one of claims 7 to 9, wherein a tooth of one of the first sealing profile and second sealing profile and an opposing recess on the other of the first sealing profile and second sealing profile are configured such that a cavity is defined between a tip of the tooth and the opposing recess when the first and second sealing jaws are in the engaged arrangement.1 1 . The packaging sealing tool of any preceding claim, wherein the elastomer strip has a round cross-section.

12. The packaging sealing tool according to any of the preceding claims, wherein the elastomer strip is a fluorocarbon elastomer with a density between 1.1 and 2.5 g / cm3.

13. A packaging sealing jaw, comprising: a first sealing profile configured to engage a second sealing profile of a second packaging sealing jaw, for sealing a packaging; and an elastomer strip; wherein the elastomer strip is configured to form part of the first sealing profile.

14. A packaging machine comprising a packaging sealing tool according to any of claims1 to 12 or a packaging sealing jaw according to claim 13.

15. A method of operating a packaging sealing tool, comprising: installing an elastomer strip into a sealing profile of a sealing jaw; using the sealing jaw to seal packaging; removing the elastomer strip from the sealing jaw without disassembling the sealing jaw; and replacing the removed elastomer strip with a second elastomer strip without disassembling the sealing jaw.

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