Flow wrapper with forming guides and fold plates and related methods

Abstract

The invention relates to a flow wrapper and a method of packaging items. The flow wrapper includes a transport mechanism configured to carry items in sequence and a former for receiving and shaping wrapping material into a tube. The tube is configured for receiving items and wrapping them for subsequent handling. The wrapping material has  two oppositely disposed outside edge regions which are brought together by the former as the wrapping material is drawn through the former. The former has forming guides which extend lengthwise in the direction of flow and are secured substantially vertically, forming the side walls of the tube. The former also includes fold plates which fold the side portions of the tube with the lower portion of the tube and are configured to bring the outside edges of the wrapping material together to be secured to one another.

Description

Field of the invention The invention pertains to flow wrappers such horizontal form fill and seal (HFFS) machines. Background and prior art known to the Applicant(s) The field of packaging machinery, specifically flow wrappers such as horizontal form fdl and seal (HFFS) machines, is a critical area in the packaging industry. These machines are typically used to wrap products in a continuous and efficient manner. The products, often arriving on a conveyor belt, are wrapped by a film that is shaped into a tunnel-like structure by a former. The two outside edge regions of the film are then sealed together using various techniques such as heat sealing or pressure sealing. One of the challenges in this field is the need to use inherently opaque material such as paper and to be able to provide the product with sufficient apertures for the product to be visible yet retained within the packaging. This is particularly important for products that need to be visible to the consumer, even when wrapped. However, traditional formers and sealing techniques may not be suitable for films with large apertures or perforations, as these could potentially damage the film or compromise the integrity of the packaging as the wrapping material is pulled through the former at relatively high velocities. The prior art machines tend to result in tears and other damage during to film or wrapping material being pulled through the former during the wrapping process. Furthermore, the use of different materials for the film, such as paper or polypropylene, can present additional challenges. These materials have different properties and may require different forming and sealing techniques. For instance, paper can be more prone to tearing or damage, especially when formed into complex shapes or when subjected to pressure. Therefore, there is a need for improvements in the design and operation of HFFS machines and formers, to address these challenges and to provide more versatile and effective packaging solutions. SUMMARY OF THE INVENTION In a first broad independent aspect, the invention provides a flow wrapper comprising: a transport mechanism configured to carry items in sequence; a former for receiving wrapping material and shaping the wrapping material into a tube which is substantially rectangular or square in cross-section; the tube comprising an upper portion, two side portions and a lower portion; the wrapping material having two oppositely disposed outside edge regions which are brought together by the former as the wrapping material is drawn through the former and as items are wrapped by the wrapping material; the former having a leading surface which gradually tapers to form the width of the upper portion of the tube; the former having side extensions separated from the leading surface by respective bends; whereby as the wrapping material is drawn through the former the material starts to form the bend between the upper portion of the tube and the side portions of the tube; the former having forming guides which extend lengthwise in the direction of flow and which present a substantially vertical forming surface; whereby the side walls of the tube are formed against the forming guides; the former further comprising fold plates which fold the side portions of the tube with the lower portion of the tube and are configured to bring the outside edge regions of the wrapping material together to be secured to one another. This configuration is particularly advantageous in certain embodiments as it may provide square or rectangular tube configurations for wrapping items whilst at the same time minimise or entirely doing away with the risk of the wrapping material tearing. It also in preferred embodiments facilitates the safe use of paper with large apertures to form packs which contain the product whilst allowing it to be at least partially visible. In a subsidiary aspect, the former has an aperture through which the tube is formed and the forming guides extend through said aperture. This further improves the definition of the edge in the tube whilst minimizing the risk of tearing the wrapping material. In a further subsidiary aspect, the fold plates act in a direction substantially perpendicular to the forming guides. This configuration is particularly advantageous in order to form rectangular tubes for wrapping around items. In a further subsidiary aspect, the fold plates comprise internal edges which are initially spaced apart and gradually come together in the direction of flow to bring the outside edge regions of the wrapping material together. This configuration further minimises the risk of tears in the wrapping material. In a further subsidiary aspect, the flow wrapper further comprises one or more rollers to present the wrapping material to the former in an initial flat configuration. In a further subsidiary aspect, the wrapping material is a film with apertures. This configuration is particularly advantageous for covering items with opaque material whilst at the same time avoiding or at least minimising the risk of the wrapping material tearing. In a further subsidiary aspect, the wrapping material is of paper. This configuration is particularly advantageous when considered in combination with the preceding aspects as the flow wrapper forms paper based tubes for wrapping items with reduced or no risk of tearing the paper. In a further subsidiary aspect, the tube has defined fold lines forming longitudinal edges at the junction between side portions and the upper portion and / or at the junction between side portions and the lower portion of the tube. This configuration is particularly advantageous in terms of mechanical strength of the packaging produce by the flow wrapper in question. In a further broad independent aspect, the invention provides a method of packaging items, comprising the steps of: conveying items in sequence to be wrapped by wrapping material; shaping the wrapping material into a tube which is substantially rectangular or square in cross-section; the wrapping material having two oppositely disposed outside edge regions which are brought together by a former as the wrapping material is drawn through the former and as items are wrapped by the wrapping material; the former having a leading surface which gradually tapers to form the width of the upper portion of the tube; the former having side extensions separated from the leading surface by respective bends; drawing the wrapping material through the former so that the material starts to form the bend between the upper portion of the tube and the side portions of the tube; providing the former with forming guides which extend lengthwise in the direction of flow and which present a substantially vertical forming surface; whereby the side walls of the tube are formed against the forming guides; further providing the former with fold plates which fold the side portions of the tube with the lower portion of the tube and thereby bringing the outside edge regions of the wrapping material together to be secured to one another. In a subsidiary aspect, the former has an aperture through which the tube is formed and the forming guides extend through the aperture. In a further subsidiary aspect, the method further comprises the step of disposing the fold plates to act in a direction substantially perpendicular to the forming guides. In a further subsidiary aspect, the fold plates comprise internal edges which are initially spaced apart and gradually come together in the direction of flow to bring the outside edge regions of the wrapping material together. In a further subsidiary aspect, the method comprises the step of further providing one or more rollers and presenting the wrapping material to the former in an initial flat configuration. In a further subsidiary aspect, the method provides wrapping material as a film with apertures. In a further subsidiary aspect, the wrapping material is of paper. In a further subsidiary aspect, the method comprises the step of shaping the tube to have defined folded longitudinal edges at the junction between side portions and the upper portion and / or at the junction between side portions and the lower portion of the tube. BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows a forward facing perspective view of a flow wrapper in accordance with an embodiment of the invention. Figure 2 shows a forward facing perspective view of a flow wrapper in accordance with an embodiment of the invention. Figure 3 shows a backward facing perspective view of a flow wrapper in accordance with an embodiment of the invention. Figure 4 shows a plan view of a flow wrapper in accordance with an embodiment of the invention and a plan view of the combination of the guides and the fold plates. Figure 5 shows a forward facing front view of the flow wrapper. Figure 6 shows a schematic side elevation of the former and its longitudinal guides. DETAILED DESCRIPTION The process will now be illustrated with reference to the figures. It begins with providing a conveyor belt that is configured to transport produce in sequence. This involves setting up a mechanical system, such as a roller conveyor, chain conveyor, or slat conveyor, that can move items from one place to another in a specific order. The conveyor belt serves as the transport mechanism for the produce that is to be packaged. The conveyor mechanism can be best viewed with reference to figure 2. Next with reference in particular to figures 1 and 3, a former generally referenced 1 is provided for receiving a flat wrapping material 2. The former is a shaping component that is designed to shape the wrapping material into a specific form. The wrapping material may be a plastic film, aluminium foil, paper or any appropriate composite material, that is used to wrap around the produce. The wrapping material is then presented into the shape of a tunnel which wraps around the produce. This involves manipulating the material in such a way that it forms a tunnellike or tubular structure that can encase the produce. The former plays a crucial role in this step as it shapes the wrapping material into the desired form. The wrapping material is received in an upper section 3 of the former. The wrapping material may be drawn from a roll of material. A number of guide rollers such as guide rollers 20 and 21 may be provided in the upper section of the wrapper to present the wrapping material in an initial substantially flat form. The process involves feeding the wrapping material into the former from the top so that it can be shaped into the tunnel form. The former presents a front face 4 which gradually tapers to form the width of the subsequently formed tube. This means that the former has a surface that narrows down to create the width of the tube that is formed from wrapping material. The former also comprises two wings 5 and 6 which are separated from the front face by respective bends 7 and 8. These wings are side extensions of the former that diverge from the front face. The wings help in shaping the wrapping material into a tube as it travels against the former. The wrapping material is drawn through the former so that the material starts to be formed into a tube as it travels against the former. This involves pulling the wrapping material through the former in such a way that it starts taking the shape of a tube or tunnel. The former is equipped with tunnel guides 9 and 10 which extend lengthwise in the direction of flow and are secured substantially vertically. These guides, which could be guide rails, guide bars, or guide plates, help in shaping the side walls of the resulting tube and assist in folding the side portions 11 and 12 of the tube relative to the upper and lower portions 13 and 14. In certain embodiments, in particular when, the wrapping material is of paper, the upper edge of the guides serve to define a fold in the resulting tube whereby the tube may have a substantially rectangular or square cross-section. The folds such as fold 22 may be viewed in figure 3. The guides 9 and 10 may incorporate a plate which is secured to the support structure 23 of the flow wrapper. As show in figure 2, the guide may preferably be secured to the support structure through one or more fasteners of known kind. Optionally, the guides may be displaced relative to one another to vary the spacing between them. This may be achieved by a displacement mechanism or actuator. As shown in figure 6 in particular, the guides may protrude significantly from both sides of the former's leading surface in order to smoothly form the upper and lower longitudinal edges of the resulting tube which is rectangular or square in cross-section. An aperture or apertures are provides between respective guides and wings 5 and 6 of the former through which the wrapping material may be drawn to start the forming process into a tube or tunnel. In particular, the upper folded edges of the tube are formed between the outermost surface of the guides and the inner most surface of the wings as can be seen in figure 3. The former is provided with fold plates 15 and 16 which draw the outside edge regions 17 and 18 (see figure 1) of the material together to form a fin 19 (see figure 3). These fold plates 15 and 16, which could also include folding arms, folding blades, or folding rollers, pull the outside edges of the wrapping material together to seal the tube. As can be best seen in figure 3, the fold plates collaborate with the guides 9,10 and the wings 5, 6 to form the lower longitudinal fold lines or longitudinal edges of the tube. Furthermore, as best seen in figure 4, the fold plates 15, 16 comprise internal edges 24, 25 which are initially spaced apart and gradually come together in the direction of flow to bring the outside edge regions of the wrapping material together to form the fin 19 of figure 3. As shown in figure 3, the principal surfaces of interaction with the wrapping material of the fold plates 15 and 16 are substantially horizontal whilst the principal surfaces of interaction with the wrapping material of the guides are substantially vertical, this combination facilitates the formation of a tube which is substantially rectangular or square in cross-section. In a similar fashion to the guides, the fold plates may also be adjustable relative to one another to vary the shape of the resulting package. Furthermore, the fold plates will be releasably fastened to the surrounding supporting structure.

Claims

low wrapper comprising:a transport mechanism configured to carry items in sequence;a former for receiving wrapping material and shaping the wrapping material into a tube which is substantially rectangular or square in cross-section; the tube comprising an upper portion, two side portions and a lower portion; the wrapping material having two oppositely disposed outside edge regions which are brought together by the former as the wrapping material is drawn through the former and as items are wrapped by the wrapping material;the former having a leading surface which gradually tapers to form the width of the upper portion of the tube;the former having side extensions separated from the leading surface by respective bends; whereby as the wrapping material is drawn through the former the material starts to form the bend between the upper portion of the tube and the side portions of the tube;the former having an aperture through which the tube is formed, the former having forming guides in the form of plates located either side of the transport mechanism and which extend lengthwise through the aperture of the former in the direction of flow and which present a substantially vertical forming surface; said plates being separate plates configured to be adjustable relative to one another to vary the shape of the resulting tube; whereby the side walls of the tube and the substantially rectangular comers of the tube are formed against the forming guides;the former further comprising fold plates which fold the side portions of the tube with the lower portion of the tube and are configured to bring the outside edge regions of the wrapping material together to be secured to one another.

2. The flow wrapper of claim 1, wherein the fold plates act in a direction substantially perpendicular to the forming guides.

3. The flow wrapper of any one of the preceding claims, wherein the fold plates comprise internal edges which are initially spaced apart and gradually come together in the direction of flow to bring the outside edge regions of the wrapping material together.

4. The flow wrapper of any one of the preceding claims, further comprising one or more rollers to present the wrapping material to the former in an initial flat configuration.21 01 255. A method of packaging items, comprising the steps of:conveying items in sequence to be wrapped by wrapping material;shaping the wrapping material into a tube which is substantially rectangular or square in cross-section; the wrapping material having two oppositely disposed outside edge regions which are brought together by a former as the wrapping material is drawn through the former and as items are wrapped by the wrapping material;the former having a leading surface which gradually tapers to form the width of the upper portion of the tube;the former having side extensions separated from the leading surface by respective bends; drawing the wrapping material through the former so that the material starts to form the bend between the upper portion of the tube and the side portions of the tube;providing the former with an aperture through which the tube is formed, the former having forming guides in the form of plates located either side of the transport mechanism and which extend lengthwise through the aperture of the former in the direction of flow and which present a substantially vertical forming surface; said plates being separate plates configured to be adjustable relative to one another to vary the shape of the resulting tube; whereby the side walls of the tube and substantially rectangular corners of the tube are formed against the forming guides;further providing the former with fold plates which fold the side portions of the tube with the lower portion of the tube and thereby bringing the outside edge regions of the wrapping material together to be secured to one another.

6. The method of claim 5, further comprising the step of disposing the fold plates to act in a direction substantially perpendicular to the forming guides.

7. The method of either claim 5 or claim 6, wherein the fold plates comprise internal edges which are initially spaced apart and gradually come together in the direction of flow to bring the outside edge regions of the wrapping material together.

8. The method of any one of claims 5 to 7, further providing one or more rollers and presenting the wrapping material to the former in an initial flat configuration.

9. The method of any one of claims 5 to 8, providing wrapping material as a film with apertures.

10. The method of claim 9, wherein the wrapping material is of paper.

11. The method of any one of claims 5 to 10, comprising the step of shaping the tube to have defined folded longitudinal edges at the junction between side portions and the upper portion and / or at the junction between side portions and the lower portion of the tube.21 01 25

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