Patent Application
20150044339
The invention pertains to the art of coating food products and, more specifically, to a system and method of coating bottom portions of food products conveyed upon a solid belt.
In the manufacturing of certain food products, it is sometimes desired to provide a surface coating on the food products. For instance, topical coatings are quite common on a wide range of food products. The overall coating process can significantly vary, particularly depending on the coating material being employed and the food product surfaces to be coated. For instance, in the case of topical coatings, whether in particulate or liquid form, it is common to provide a feed hopper or other dispenser above the food product as the product moves along a conveyor. In such an arrangement, the conveyor belt is generally formed of interconnected metal wires or links which enables most of the excess coating material to fall or flow through the conveyor belt and collected for reuse. If it is desired to coat the bottom and even sides of a food product, the conveyor belt can be directed into a container of the coating material, essentially dipping the food product and mesh conveyor belt in the coating material. In the art, this type of coating system which enables coating of multiple surfaces of a food product is often referred to as an enrober.
Known enrobers are considered to be quite expensive and complicated. In addition, in the food industry, the conveyors must be cleaned at regular intervals, which can be important for various reasons including allergins. At least in the case of liquid coating enrobers, cleaning the links of the conveyor is extremely difficult and time consuming. By way of example, in the range of twenty to thirty-five hours of man-time is often required to clean an open mesh conveyor of an enrober system used to apply chocolate to the bottom of chewy grain bars. Obviously, this represents a significant amount of downtime for a production line.
The invention is directed to a system and method for enrobing at least bottom and partial side portions of food products by utilizing a conveyor unit employing a solid belt at a coating station. More specifically, the invention provides for a product conveying system including at least first and second, sequentially arranged conveyor belts, with at least the second conveyor belt being constituted by a solid belt. Interposed in a gap between the first and second belts is a dispenser head of a coating manifold. An upper surface of the second conveyor belt is arranged in a plane just below a plane of an upper surface of the first conveyor belt such that the dispenser head spans the gap, with an elongated outlet portion of the dispenser head being exposed, in a downstream direction of the system, to an upper surface of the second conveyor belt.
During operation, the manifold receives a liquid coating material and dispenses the coating material directly onto a predetermined percentage of the overall width of the second, solid belt while spaced food products are directed from the first belt into the coating material on the second belt. In accordance with an aspect of the invention, the coating material is thick so as to not ready flow off the belt, thereby avoiding the need for any lateral containment structure on the solid belt. With this arrangement, the coating material coats the bottom or lowermost side of the food product, as well as extending up and coating side portions of the food product to a degree dependent upon the food product being coated and the coating thickness or height applied to the solid belt. Downstream of the dispenser head, the coated food product is removed from the solid belt and the excess coating material is scraped from the belt, collected, filtered and recycled back to the manifold.
In accordance with a particular embodiment of the invention, the coating material is thick, melted chocolate which is applied onto the solid belt with a low pressure drop (e.g., less than 0.1 psig) across the horizontal portion of the head and a higher pressure drop (e.g., preferably in the range of 2-30 psig and, more preferably, 7-12 psig) across the vertical portion of the dispenser head to provide a uniform layer thickness across the belt. The layer thickness depends on the desired coating weight and is preferably about 6-9 mm for bottom coating chewy grain bars and 2-5 mm for bottom coating of crunchy baked bars. Layer thickness is primarily varied by how much coating is applied to the belt. Upon reaching a downstream end of the second belt, the coated bars are automatically transferred onto a third conveyor belt which is also solid and constitutes a cooling or chill belt, establishing a predetermined cooling temperature and residence time. Still, the invention has applicability to a wide range of coatings and products, basically coating materials which can be heated and cooled to alter viscous characteristics thereof and food products which can be sheeted and conveyed. In any case, additional objects, features and advantages of the invention will become more readily apparent from the following detailed description when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
With initial reference to
As will become more fully evident below, the present invention can be used in coating bottom and partial side portions of various products. In one particular embodiment, coating system 2 is used in coat food products 45 in the form of chewy grain bars, each having a bottom surface 47, a front side surface 48, a rear side surface 49, lateral side surfaces 50 and 51, and a top surface 52. As shown, the previously prepared food products 45 have been deposited on upper surface 21 in rows and columns for transport by conveyor belt 12 from transfer station 6 to a downstream coating station 55. Coating station 55 includes a second conveyor unit 59 employing a second conveyor belt 63 having, in the position illustrated, a first longitudinal end 66 supported by a roller 67 and a second longitudinal end 68 supported by a roller 69, with conveyor belt 63 establishing an upper surface 73 between first and second longitudinal ends 66 and 68. From upper surface 73, conveyor belt 63 leads to a down-turned portion 76 extending around a drive roller 79 of a drive unit 82, which may include a pulley 84 such as for a common drive with drive unit 32, and an upturned portion 88 leading back to first longitudinal end 66.
For reasons which will be detailed more fully detailed below, it is important in accordance with the present invention that second conveyor belt 63 is constituted by a solid conveyor belt, without any associated open mesh metal wires or links. In the embodiment shown, conveyor belt 63 is formed entirely from a polymeric material, such as a polyester base provided with a polyurethane topcoat. That is, in order to not depart from the invention, conveyor belt 63 must be solid, at least across a majority of the lateral dimension or width of conveyor belt 63. However, prior to further detailing this important aspect of the invention,
As best shown in
Prior to describing the overall operation of coating system 2, further structure associated with the present invention will now be described in connection with the illustrated embodiment. Initially, as shown in
In accordance with a particular embodiment of the invention, the coating material is thick, melted chocolate which is applied onto the solid belt with a low pressure drop (e.g., less than 0.1 psig) across the horizontal portion (not separately labeled) of dispenser head 164 and a higher pressure drop (e.g., preferably in the range of 2-30 psig and, more preferably, 7-12 psig) across the vertical portion (not separately labeled) of dispenser head 164. This assures an even flow, with food products 45 becoming partially immersed in coating material 180 such that coating material 180 will become enrobed on at least bottom surface 47 and portions of front, rear and side surfaces 48-51. The layer thickness depends on the desired coating weight and is preferably 6-9 mm for bottom coating chewy grain bars and 2-5 mm for bottom coating of crunchy baked bars. At the same time, presser unit 188 can further assure that an appropriate tap-down force is applied on food products 45 for proper coating. Once reaching second longitudinal end 68, the coated food products 298 are transferred onto third conveyor belt 113 of cooling station 105, while excess coating material 180 is delivered into hopper 253 in conjunction with scraper device 265. Any tailing of the coating material 180 associated with the transfer to cooling station 105 is avoided by the presence of spinner device 276.
The length of first conveyor unit 9 will depend on the overall manufacturing configuration. On the other hand, the length of second conveyor unit 59 can actually be quite short, such as less than 2 meters, along with a preferably commensurate width. The length of third conveyor unit 110 will depend on the time need to cool and further solidify coating material 180. In the case of chocolate, a rather long cooling period is typically needed, such as about a 3 minute residence time. With this in mind, this length can be from 12-25 meters, but can be advantageously reduced to about 3 meters utilizing certain conveyor material and a flat, aluminum plate cooling system. To this end, a thin, high heat transfer material, such as TEFLON, having a thickness in the order of about 0.025 cm (10/1000 of an inch) can be advantageously employed as the conveyor material such that this overall chilling arrangement can reduce the cooling time to approximately 40 seconds.
Although described with reference to exemplary embodiments of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, other than applying chocolate, various other coating materials which can be heated and cooled could be employed, including yogurt, marshmallow, fruit and cheese. In addition, other food products which can be sheeted and conveyed could be coated, including candy, dough, cereal, cookies and ice cream. Most importantly, it has been found that completely avoiding mesh metal conveyor materials but rather utilizing the solid and small length (less surface area) conveyor belt as discussed above for the coating operation enables the cleaning time to be significantly reduced, basically from about thirty-five hours to about four hours, thereby representing a major efficiency enhancement.
