GB2544852A

GB2544852A - System and method for applying a coating to a film

Info

Publication number: GB2544852A
Application number: GB1615249.8A
Authority: GB
Inventors: Sheikh Shahid; D'Souza Shane
Original assignee: CLIFTON PACKAGING GROUP Ltd
Current assignee: CLIFTON PACKAGING GROUP Ltd
Priority date: 2015-10-01
Filing date: 2016-09-08
Publication date: 2017-05-31
Anticipated expiration: 2036-09-08
Also published as: GB2543038A; GB2545050B; GB201616802D0; GB2543038B; GB2544852B; GB201615249D0; GB201517379D0; GB2545050A

Abstract

The apparatus includes a reservoir 232 containing an antibacterial solution 230 and cylinders 220, 240, at least one of which guides the plastics film 210. The method comprises submerging a cylinder 240 within the reservoir to coat the exterior surface of the cylinder with the antibacterial solution and guiding the plastics film over the exterior surface to coat a surface of the film with the antibacterial solution. The preferred apparatus includes a gravure cylinder 240 or flexo plate (360, figure 3). Preferably the solution 230 also contains an indicator. The preferred method involves heat drying or ultraviolet (UV) curing the coated film. The film is used for sealing wet protein food products.

Description

DESCRIPTION

SYSTEM AND METHOD FOR APPLYING A COATING TO A FILM

Field

The disclosure describes a method and system for applying a coating to a film. Background

Contamination of food products by bacteria such as by Campylobacter is a known problem in food preparation and packaging industries. The issue is particularly relevant to food packaging industries for fresh food products such as wet protein products including raw poultry. Whilst many measures are in place to reduce the risk of bacterial contamination, including the use of machine automation, anti-bacterial sprays, and anti-bacterial wipes, risks remain.

The sale of raw meat, in particular poultry, more particularly chicken, typically involves packaging made out of 3 components. A tray, such as a rigid plastic or polystyrene tray or container on which the meat is placed, a plastic film and a conventional wrap label are all required. Such packages are sometimes called tray lidded CAP (controlled atmosphere packaging) packs. Such packages are typically sold in the chiller cabinets of supermarkets as a fresh product.

One area of concern is contamination of the exterior of food packaging by bacteria. This may be caused, for example, by the presence of small amounts of raw wet protein matter on the exterior of the packaging. Such contamination can occur during filling of the food packaging, or may occur at other stages of the packaging process. As an example, for tray lidded CAPs, these typically require manual handling during filling to ensure that the product is orientated the correct way in the packaging. Manual handling can cause cross contamination including transfer of uncooked meat juices or products to the outside of the tray, lid, conventional wrap, staff and all ancillary equipment.

The presence of such bacterial matter on the exterior of the food packaging can cause further cross contamination. For example, if the exterior of a fresh wet protein packaging is contaminated with bacteria, when bought by a consumer, the packaging can cross contaminate other food items and packaging into which the contaminated packaging has been brought into contact with. Additionally, contamination can occur in store or within shopping trolleys etc. Given that (in supermarket consumer trolleys in particular) such food packaging can be in close contact with foodstuffs intended for raw consumption, such as fruit and vegetables, and the risk of cross contamination becomes clear.

As noted above, current measures such as antibacterial sprays and wipes do not fully solve the issue and may require additional stages in the production process, which is undesirable. It is also, at present, difficult for a retailer to determine whether antibacterial measures have been applied to a product. It is an object of the present disclosure to alleviate these issues.

Summary

According to a first aspect of the present disclosure, there is provided a system for applying a coating to a film for sealing a wet protein food product, said system comprising: a plurality of cylinders for applying one or more coatings to the film, wherein at least one of said coatings is an antibacterial coating.

In an embodiment, at least one of said coatings may contain a tracer indicative of the presence of the antibacterial coating. Said coating may be a luminescent tracer or a photosensitive tracer as defined in relation to the first aspect.

The anti-bacterial coating may be applied by a sandwich printing technique. In one embodiment, said cylinder for applying the antibacterial coating may be a gravure cylinder. In an alternative embodiment, said cylinder for applying the antibacterial coating may be a flexo plate. Other known printing techniques may be used to coat the film with the antibacterial coating.

In embodiments, the antibacterial coating may be provided as an antibacterial solution in a reservoir such that the cylinder rotates within the reservoir to coat the cylinder with the antibacterial solution. The cylinder may then contact a surface of the film to print or apply the antibacterial solution to the film. The solution may be applied to the one or both surfaces of the film.

In embodiments, the system may include a dryer for drying the applied antibacterial coating to the film. Heat may be used. Additionally or alternatively, ultra-violet light may be used to cure the antibacterial coating.

According to a second aspect of the present disclosure, there is provided a method for applying an antibacterial coating to a plastics film, said method comprising the steps of: providing a reservoir containing an antibacterial solution; providing one or more cylinders for guiding the plastics film; submerging at least one cylinder within the reservoir to coat the exterior surface of the cylinder with the antibacterial solution; and guiding the plastics film over the exterior surface to coat a surface of the film with the antibacterial solution.

As described above, the method may further comprise drying or curing steps using heat from a heater or cured with light, such as ultra-violet light from an ultra-violet lamp.

For both the first and second aspects, the antibacterial coating is applied as a separate process to printing of the film with graphics or the like, film lamination or other processes. Such lamination and printing processes typically occur before the film is supplied to the system of the second or third aspect to apply the antibacterial coating and optionally the tracer/taggent.

According to a further aspect of the present disclosure, there is provided packaging for storing and displaying raw wet protein portions, said packaging comprising: a tray for containing one or more portions of raw wet protein; and a film sealing the tray, wherein the film is provided with an antibacterial coating.

In embodiments, the antibacterial coating may be provided to the exterior of the film. Applying the antibacterial coating to the exterior of the film helps to prevent cross contamination between the food product and other items that the food product may come into contact with.

Additionally or alternatively, the film and/or the coating may be transparent to allow the food product in the tray to be seen through the film. The film may be flow wrap, pouches or other suitable material, typically laminated plastics.

An example of the antibacterial coating includes coatings that may comprise silver ions. Other antibacterial coatings include chemical coatings such as triclosan containing coatings. It can be appreciated that the composition of the anti-bacterial coating can be selected based on the intended use and/or the expected bacterial contaminate. The antibacterial coating may comprise an antibacterial powder, a solvent for dissolving the powder and ensuring an even coverage of antibacterial coating on the film, and a lacquer for protecting the coating and/or for ensuring that the antibacterial coating is impregnated in the film.

In embodiments the antibacterial coating may comprise a tracer (also known as a taggent) indicating presence of the coating. The use of a tracer or taggent provides a means of authenticating and testing for the presence of the antibacterial coating. The tracer may be a photosensitive tracer that allows visual detection by a laser pen or a suitable detector.

For example, the tracer or taggent may be sensitive to infra-red light. This allows a detector to be used configured to detect the presence of or lack of presence of a response from the film to infra-red light. In this manner, the detector may illuminate the film with infra-red light having a particular wavelength, that may be narrowly defined, and detect reflection and/or absorption characteristics of the light.

In embodiments of the packaging, the tracer may be provided as a coating to the film. Alternatively, the tracer may be combined with the antibacterial coating as an additive or may be intrinsic to the antibacterial coating (i.e. the antibacterial coating has properties that allow it to be used as a tracer, such as photo-sensitivity).

In embodiments, the tracer may be provided to the exterior of the film. The tracer may be a luminescent tracer. The luminescent tracer may be configured to emit light when illuminated with light of a particular wavelength. The light may be of a particular frequency or wavelength. Alternatively or additionally, the tracer may be reflective and configured to reflect light of a particular wavelength.

Exemplary substrates include one or more plastics, such as polyethylene (PET) and its derivatives and/or polyester (CPP) and its derivatives. In embodiments, the film may be a laminated substrate. Said laminated substrate may be a laminate of two or more plastics, such as one or more layers of PET and one or more layers of CPP.

According to an aspect of the present disclosure, there is provided a method of detecting antibacterial food packaging, said method comprising the steps of: providing food packaging coated concomitantly with an antibacterial coating and a tracer coating; providing a reader for detecting presence of the tracer, wherein a positive reading indicates presence of the tracer.

These and other aspects of the disclosure will be apparent from, and elucidated with reference to, the embodiments described hereinafter.

Brief description of Drawings

Embodiments will be described, by way of example only, with reference to the drawings, in which figure 1 is a schematic of packaging having a film with an antibacterial coating according to an embodiment of the present disclosure; figure 2 is a cross-sectional schematic of an embodiment of a system for coating film with an antibacterial coating; figure 3 is a cross-sectional schematic of an alternative embodiment of a system for coating a film with an antibacterial coating; figure 4a is a detector configured to detect the presence of a tracer indicating application of the antibacterial film for a film that does not have an antibacterial coating; and figure 4b is a detector configured to detect the presence of a tracer indicating application of the antibacterial film for a film that does have an antibacterial coating.

It should be noted that the Figures are diagrammatic and not drawn to scale. Relative dimensions and proportions of parts of these Figures have been shown exaggerated or reduced in size, for the sake of clarity and convenience in the drawings. The same reference signs are generally used to refer to corresponding or similar feature in modified and different embodiments.

Detailed description of embodiments

Figure 1 shows packaging 100 for storing and presenting food stuffs. In particular, the packaging comprises a tray 110 with a substantially flat bottomed portion 112 and a film 120 configured to form a closure to seal the tray 110. The film 120 is located against a lip 122 of the tray and is typically heat shrunk against the tray to melt the film 120 to the tray 110. The tray typically is used to contain and present raw wet protein food stuffs, such as poultry, more particularly chicken.

The film 120 is typically a laminate film (although a standard film may be used) and is made from a combination of one or more plastics, such as polyethylene (PET) and its derivatives and/or polyester (CPP) and its derivatives. The type and composition of the plastics used can be tailored to the required application. Some plastics are more suitable to heat shrinking, whilst others are better to print graphics and text to.

The film is treated with an antibacterial coating 130. The antibacterial coating 130 is typically a composition containing silver ions, although chemical compositions, such as triclosan, may be used. The antibacterial coating 130 ensures that any stray food stuffs from within the tray 110 and not sealed by the film 120, for example, contaminants during packaging of the food stuffs into the tray 110 prior to sealing, do not pose a bacterial contamination threat.

The antibacterial coating 130 is typically applied as will be described below in relation to figures 2 and 3. The antibacterial coating 130 is typically a powder containing the antibacterial agent, which is combined with a solvent to dissolve the powder and to aid even coating when applied to a plastics film. In addition, a lacquer is typically used to ensure a smooth finish. The coating 130 is typically dried or cured onto the film 120 as will be described below.

Additionally, the antibacterial coating 130 can contain a tracer that acts as a marker to provide proof that the antibacterial coating 130 has been successfully applied to the film 120. Such tracers may be photosensitive compounds, such as reflective compounds configured to reflect light of a known wavelength, luminescent markers, or the like. For laminate films 120, the tracer may be applied to the same layer or side of the film 120 as the antibacterial coating 130, or it may be applied to different layers or sides. Additionally, the tracer may be combined with the antibacterial coating 130.

Figure 2 shows an exemplary embodiment of a system 200 for applying an antibacterial coating 130 to a film 210. It can be appreciated that the film 210 may have been processed in printing and/or lamination systems and processes prior to being provided to the system 200. The general process is a gravure printing system. The film 210 is passed through the system 200 in the direction shown 212 by an impression cylinder 220 rotating in an anticlockwise direction 222 (in this example). Concomitantly, a gravure cylinder 240 is immersed within a reservoir 232 in which an antibacterial solution 230 is provided. Rotation of the gravure cylinder 240 collects antibacterial solution 230 into the surface 242 of the gravure cylinder 240. The surface 242 becomes impregnated with antibacterial solution 230. A doctor blade 260 removes excess solution 230 from the surface 242 and returns it to the reservoir 232. A core 244 coupled to a drive mechanism rotates the surface 242 in the direction shown 245. The gravure cylinder 240 and the impression cylinder 220 are configured to meet at point 246. Due to the relative movement between the cylinders 220, 240 and the saturation of antibacterial solution 230 in the surface 242 as shown by 248, the lower surface 270 of the film 210 is coated with the antibacterial solution as it is passed through the system 200.

An alternative mechanism and system 300 is shown in figure 3. Like references are used for like parts of figure 2. Figure 3 depicts a flexo coating process. A central impression chamber 320 receives a film 310 and drives the film 310 through the system 300. It can be appreciated that the film 210 may have been processed in printing and/or lamination systems and processes prior to being provided to the system 200. Like figure 2, a reservoir 332 contains antibacterial solution 330 and a pick-up roller 340, with surface 342 and core 344. The roller 340 is immersed within the reservoir 332 and rotates 345 to coat and saturate the surface 342 with the antibacterial solution 330 as shown in 348.

The antibacterial solution is transferred to an anilox roller 350 via contact point 354. The anilox roller rotates 352 and contacts and transfers the antibacterial solution on its surface 356 to the surface 362, 366 of a flexo plate 360 via contact point 364 as the two rollers 350, 360 rotate relative to each other. Excess antibacterial solution on the surface 356 is removed by a doctor blade 358.

The flexo plate 360 rotates 365 and antibacterial solution present on the surface 366 of the flexo plate 360 is transferred to the surface 370 of the film 310 via contact point 368 as the film 310 is fed through the system 300. After coating, the surface 369 of the flexo plate 360 is substantially free of antibacterial coating.

Once applied to the film 210, 310 by either system 200, 300, dryers and/or curing equipment can dry/cure the coated surface 270, 370. Heat can be used as a drying agent and ultra-violet light as a curing agent.

As noted above, the antibacterial solution 240, 340 may contain a tracer compound. Alternatively, a tracer compound may be coated onto the surface of the film 210, 310 in a similar manner to that used to coat the surfaces of the film 210, 310 with antibacterial solution. A detector can be used to indicate the presence of the tracer compound. An example is shown in Figure 4a, 4b.

Figure 4a shows a tray 410 with a film 412 that has not been coated with the antibacterial or tracer coatings. For this example, the tracer is considered to be within the antibacterial coating. When a detector 414 is placed on the film 412, no signal is emitted by the indicator 416. This result indicates that no antibacterial coating is present because no tracer compound has been detected by the detector.

Figure 4b shows an alternative tray 420 that has a film 422 which has been coated with the antibacterial and tracer coating. Upon placing of the detector 414 onto the surface of the film 422, the indicator 416 lights, providing an indication that the antibacterial coating is present.

The detector 414 typically operates by emitting a light of a known wavelength onto the film and detecting the presence (or absence) of transmission of the light. The wavelength may be a tightly defined wavelength, such as infra-red light. A positive result is provided if the tracer is present in the coating of the film, i.e. if the tracer transmits the emitted light back to the detector 414. Photosensitive or luminescent tracers may be used, with the detector 414 configured accordingly. A laser pen may be used with some tracer/taggent coatings, wherein visual detection is possible by analysing the reflection characteristics.

From reading the present disclosure, other variations and modifications will be apparent to the skilled person. Such variations and modifications may involve equivalent and other features which are already known in the art of, and which may be used instead of, or in addition to, features already described herein. For example, although wireless signals are typically referred to, the skilled person would appreciate the application of the present disclosure to nonwireless signals, particularly those that utilise interleaving.

Although the appended claims are directed to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the present invention.

Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. The applicant hereby gives notice that new claims may be formulated to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom.

For the sake of completeness it is also stated that the term "comprising" does not exclude other elements or steps, the term "a" or "an" does not exclude a plurality, a single processor or other unit may fulfil the functions of several means recited in the claims and reference signs in the claims shall not be construed as limiting the scope of the claims.

Claims

1. A system for applying a coating to a film for sealing a wet protein food product, said system comprising: a plurality of cylinders for applying one or more coatings to the film, wherein at least one of said coatings is an antibacterial coating.

2. A system according to claim 1, wherein at least one of said coatings contains a tracer indicative of the presence of the antibacterial coating.

3. A system according to claim 1 or claim 2, wherein said cylinder for applying the antibacterial coating is a gravure cylinder.

4. A system according to claim 1 or claim 2, wherein said cylinder for applying the antibacterial coating is a flexo plate.

5. A system according to any preceding claim, wherein the antibacterial coating is provided as an antibacterial solution in a reservoir such that the cylinder rotates within the reservoir to coat the cylinder with the antibacterial solution.

6. A method for applying an antibacterial coating to a plastics film, said method comprising the steps of: providing a reservoir containing an antibacterial solution; providing one or more cylinders for guiding the plastics film; submerging at least one cylinder within the reservoir to coat the exterior surface of the cylinder with the antibacterial solution; and guiding the plastics film over the exterior surface to coat a surface of the film with the antibacterial solution.

7. The method of claim 6, further comprising the step of: drying the surface of the film using heat; or curing the surface of the film using ultra-violet light.