Patent Application
20100101682
1. Technical Field
The present invention relates to a method and apparatus for reducing product breakage in a packaging machine.
2. Description of Related Art
Breakage is a problem with virtually any process wherein a package is filled with product, such as a food product. Often, the amount of breakage is dependent on the fragility of a product. Typically homogenous products are less likely to experience breakage as they often comprise less “weak points” which exhibit a tendency to break. The product geometry also affects the tendency of the product to break. Regardless of the product, however, the extent of the breakage is dependent on the process used to package the product.
There are a variety of methods and apparatuses employed to deliver product into a package which are known in the prior art. Many comprise a series of tunnels or chutes which guide and direct the product into a package 107.
Product from the statistical weighers 101 is typically transferred into a series of funnels and tubes until it has finally reached its packaging bag 107. These funnels and tubes vary in diameter and size. Often the funnels are separated by a distance of 3 feet or more in which the product can accumulate significant vertical velocity. The chutes can be funnels, as illustrated in
Referring again to
The final product conduit 106 used may comprise a variety of means for depositing a product into a package 107. As illustrated, the final product conduit 106 comprises a simple funnel. However, the prior art discloses that the conduit 106 may include sophisticated moving parts such as jaws which are used to simultaneously fill and form the package. Often the packaging machines comprise an absorber which allows product to be softly received into the package. In other words, the package is held in place in such a way as to absorb a portion of the product momentum and reduce breakage. Regardless, typically a conduit 106 is employed to deposit the product into the package.
Unfortunately, when employing a filling apparatus such as the one discussed, the product often becomes broken at some point after the statistical weighers 101. Accordingly, when a consumer opens the package there is often several broken product pieces as well as a volume of crumbs or scraps of product accumulated in the bottom of the package. This is obviously objectionable for a variety of reasons. First, it is almost always desirable to have a whole product. For example if the product is a chip, a chip is desirable as the consumer may be dipping the chip. Further, breakage is undesirable because the broken product tends to collect at the bottom of the package, giving the appearance of a less full bag. A package comprising whole product pieces appears fuller to the consumer and thus more desirable. Accordingly, it is desirable to find an apparatus or a method wherein the product breakage is eliminated or reduced. Further, it is desirable to have a method or apparatus which results in a package which has the appearance of being fuller when opened. It is desirable that any method or apparatus not severely limit the speed in which bags can be made and filled. Furthermore, because many packages involve a vertical, form, fill and seal machine, it is desirable that this product be flexible enough for use on such a machine, preferably with only minor modification.
An apparatus and method for reducing product breakage while filling a product into a package is provided. The invention describes reducing the momentum of product falling through a filling apparatus to reduce collisions of the product with other product and with the apparatus, thus reducing breakage. In one embodiment, the apparatus comprises at least one funnel, a steering funnel, which comprises steering vanes. These steering vanes, located on the face of the funnel, impart a swirling motion upon the product dropped within the funnel. Thus, a swirling motion is imparted onto the product which reduces the vertical momentum of the product and which reduces the number and strength of the collisions.
In another embodiment, the apparatus comprises a funnel and a product conduit used for depositing the product into the package located downstream of the funnel. A bumper which is in substantially the same vertical plane as the exit end of the tunnel is suspended somewhere above the lower end of the product conduit but below the exit end of the funnel. As product falls through the funnel it encounters the bumper. The bumper is flexible to absorb momentum without itself causing breakage. Because of the reduced momentum, the strength of the collisions is reduced which likewise reduces the product breakage.
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
Several embodiments of Applicants' invention will now be described with reference to the drawings. Unless otherwise noted, like elements will be identified by identical numbers throughout all figures.
Generally, this invention relates to a method and apparatus for preventing breakage during packaging. A goal is to reduce breakage by reducing the high velocity of the product and more specifically by elimination of the high momentum product-to-product collisions as well as the high momentum product-to-apparatus collisions. The invention can suitably be used on a standard vertical form, fill, and seal machines known well in the art. However, the invention is not limited to vertical form, fill, and seal machines, as the instant invention can be utilized on virtually any packaging apparatus. Referring back to
It should be noted that while Applicants generally refer to the filling apparatus of
Referring now to
While
The steering vanes 201 illustrated in
The steering vanes 201 impart a swirling motion to the product. This is contrasted to the prior art wherein the product follows the slope of the funnel and is directed in the most directly vertical path wherein there is great velocity in the vertical or Y direction and comparatively little velocity in the horizontal or X direction. The steering vanes 201 impart a swirling motion to the product wherein a portion of the vertical momentum is transferred into horizontal momentum, and more specifically into a rotational or helical momentum as the product swirls. The height, length, and orientation of the steering vanes 201 can be adjusted to achieve a desired swirling motion. As can be appreciated, as the swirling motion is increased, the vertical velocity is decreased. As a result, the throughput of product per unit time through the second funnel 103, and consequently through the entire filling process is decreased. This has a direct effect on the number of packages which can be filled in a given time. Thus, those skilled in the art will appreciate that a given product can be optimized for optimal throughput in terms of bags per unit time and acceptable breakage.
In the depicted embodiment the steering vanes 201 extend beyond the exit end of the funnel. This provides an opportunity to provide an increased swirling motion to the product. In another embodiment the steering vanes 201 extend only for the length of the funnel, whereas in other embodiments the steering vanes 201 do not extend for the entire length of the funnel. In still other embodiments the steering vanes 201 begin straight but later curve, while in other embodiments the steering vanes 201 begin curved but later straighten. Often such embodiments are used to accommodate existing equipment which cannot be replaced or modified. Those skilled in the art will appreciate that process, apparatus, and product circumstances may dictate minor changes in the location, orientation, geometry, length, etc. of the steering vanes 201. Thus, the many variables surrounding the steering vanes 201 may be adjusted to optimize a variety of parameters in a process including breakage and product throughput.
In
As discussed, the steering vanes 201 give the product a swirling motion. Thus, as product is dumped from statistical weighers 101 into the first funnel 102 and into the second funnel 103, the product begins to swirl. It should be noted that while statistical weighers 101 are discussed in one embodiment the instant invention is not so limited. The instant invention may successfully be employed in virtually any weigher including volumetric weighers, single bucket drops, and continuous product streams.
Because the product begins to swirl, when it encounters the third funnel 104 along with product tube 105, not all of the momentum is concentrated on the impact point 108. Instead the product swirls in a circular direction down the tube. This slightly decreases throughput and greatly reduces breakage at the impact point 108.
Likewise, Applicants offer another improvement to reduce the effect of the impact point located near the junction of the product tube 105 and the product conduit 106. As discussed above, often the product tube 105 has a circular cross section whereas the product conduit 106 often has a square cross section. To decrease the effect of the transition from a round cross section to a square transition, in one embodiment the cross section of the product tube 105 gradually transitions to a square cross section at the junction with the product conduit 106. Likewise, in other embodiments the product conduit 106 gradually transitions to a circular cross section at the junction with the product tube. Such changes reduce the possible impact points which can result because of the change in cross sections.
As will be discussed below, the speed of packaging is a function of several factors including, but not limited to, the product type, uniformity of product, density of the product, geometry of the product, length and orientation of the steering vanes, product spread, as well as the acceptable product breakage. With regard to one flat and uniform, cracker-like product, bag rates of about 1 to about 60 bags per minute have been achieved. Again, however, the bag rates are product dependent, thus these examples should not be deemed limiting as higher bag rates can be achieved as discussed below. In another embodiment bags have rates of 1 to about 60 bags per minute. In another embodiment, the bags have rates of about 30 to about 60 bags per minute. In still another embodiment, the bags have rates of about 50 and about 60 bags per minute. As previously described, the steering vanes 201 give the product a swirl motion which decreases the vertical velocity of product down through the series of funnels. Accordingly, in a given series of funnels, the steering vanes 201 will result in a larger residence time than if the steering vanes 201 are not used. As used herein “residence time” refers to the time a product spends in a given funnel or series of funnels. Further, the steering vanes 201 cause the product to spread out further along the series of tunnels than if the product was allowed to fall directly through the series of funnels. Accordingly, the use of steering vanes 201 increases the amount of product scatter. As used herein “product scatter” is the time from when the first product enters the package 107 and the last product enters the package 107. Thus, a method which comprises little product scatter is one wherein all of the product enters the package at roughly the same time. As stated above, the use of steering vanes 201 typically increases the amount of product scatter. This results from the fact that the total distance between the first and last product is increased as a result of the steering vanes 201. The amount of product scatter dictates the number of maximum packages per minute which can be filled; increased scatter means more time must be dedicated to filling an individual package with product. Accordingly, for a given product scatter there is a maximum number of packages per minute which may be filled. Those skilled in the art will appreciate that the product scatter for a given product is a function of the length, orientation, etc. of a steering vane 201, as well as the density, uniformity, geometry, and other variables of the product. Thus, the product scatter, and consequently, the maximum bags per minute is a function of the steering vane 201 employed and the product being packaged.
Table 1 below illustrates the reduced breakage which results from using the steering vanes of the instant invention. The data was taken on a filling apparatus similar to that described in
The above table illustrates the effectiveness of implementing steering vanes on one product type. Whole pieces are pieces which have not been broken. It can be seen that the percentage of whole pieces increases substantially when using steering vanes. As discussed above, this is desirable as a consumer typically desires a whole product. Partial pieces are those pieces which have been broken and are larger than half of the product. The percentage of partial pieces decreased when utilizing Applicant's steering vanes. Likewise, the percentage of scrap, or broken pieces smaller than half of the product, also dramatically decreased. Again, Table 1 illustrates that a substantial reduction in breakage results by adding steering vanes.
Applicants note that a variety of products may be utilized in the apparatus described herein. Those skilled in the art will appreciate the subtle nuances that require adjustment to account for the product changes. As discussed, the size of the product may dictate the length, curvature, etc. of a steering vane 201. As can be appreciated, because the steering vanes often start at the larger outer diameter of a funnel and finish at the smaller outer diameter at the bottom of the funnel, the distance between steering vanes 201 is typically greater at the top of a funnel than at the bottom of the funnel. As discussed, it can be appreciated that for certain products the gap between steering vanes 201 at the bottom of the funnel is preferably larger than the product being packaged. However, as stated above, this limitation is highly product dependent as some products may become broken, damaged, or lodged if the distance between steering vanes is smaller than the product being packaged whereas in other products this is not as large of an issue. As stated above, uniform and discrete product can generally tolerate smaller gaps. Generally, the non-uniform products are the products which require larger gaps. In such products, utilizing smaller gaps may result in increased bridging. Bridging, as used herein, refers to product becoming lodged or stuck in a restricted position. Product which becomes lodged can then cause other product to become lodged forming bridges of lodged product. Even if the product does not become lodged between steering vanes 201, the product may be slowed because of the narrow gap which is likewise undesirable as it decreases the maximum possible bag rate.
Applicants have discovered another embodiment to alleviate the problems associated with bridging.
Furthermore, triangularly shaped steering vanes may be well suited in embodiments wherein the small diameter of the funnel is set at a maximum for processing reasons. For example, if the exit diameter of a funnel exactly matches the diameter of a product tube which cannot be replaced, then the funnel exit diameter cannot be changed. In such situations, a pinch point problem cannot simply be solved by replacing the funnel with a larger diameter funnel as is possible in other scenarios. Instead, the user may employ triangularly shaped steering vanes 401 which decrease the effect of a pinch point without adjusting the diameter size of the funnel. While both perpendicular wall steering vanes 201 and triangular steering vanes 401 have been described, those skilled in the art will appreciate that other steering vane geometries may be desirable for a given product and/or apparatus including for example, semi-circle cross sections.
Now that a filling apparatus has been described, a method of reducing product breakage will be discussed. The method comprises the steps of introducing product into a filling apparatus, imparting a swirling motion onto the product, and filling said product into a package, wherein the imparting step comprises using at least one funnel which comprises steering vanes. This advantageous method can be performed on most existing filling apparatuses by replacing at least one pre-existing funnel with a steering funnel comprising steering vanes. Thus, with only minor equipment changes the breakage of a product can be significantly reduced. Additionally, the method and apparatus discussed herein requires no moving parts on the steering funnel. This is advantageous in that it reduces capital costs and limits the opportunity for mechanical failure.
Referring now to
As depicted, the free floating bumper 502 is secured by the floating securing device 501. In one embodiment, the floating securing device 501 is secured to the combinational weighers 101. In such an embodiment, the floating securing device 501 typically passes through at least one funnel upstream of the free floating bumper 502. Thus, referring back to
As depicted, the third funnel 104 has a receiving end and an exit end. The receiving end is the top end of the funnel and, as shown, comprises a larger diameter. The exit end is the bottom end of the funnel and, as shown, comprises a smaller diameter than the receiving end. Again, funnels without sloped walls may also be utilized in this invention. The exit end of the third funnel 104, in the embodiment depicted, is connected to the top end of the product tube 105. It should be noted that in other embodiments the exit end of the funnel 104 is not directly connected to the top end of the product tube 105 but is simply located above it.
It can be appreciated that after product exits the second funnel 103, it will impact bumper 502 and will lose momentum. In this manner, breakage is reduced or eliminated because the collision which could otherwise take place at impact point 108 is eliminated. Additionally, the bumper 502 prevents product from colliding with itself, further decreasing breakage. As discussed above, without a bumper, product from substantially opposite sides of the funnel are directed to each other wherein they collide and break.
The bumper 502 can be located in a plurality of advantageous positions. In each of these positions, the bumper 502 is in the substantially same vertical plane as the product tube 105 and the exit end of the funnel 103. Further, in many embodiments, the bumper 502 is located upstream of the bottom end of the final product conduit 106; the bumper 502 does not extend past the bottom end of the final product conduit 106. If the bumper 502 extends past the final product conduit 106, it may interfere with the filling of the package with product. For this reason, in some embodiments the bumper does not extend beyond the bottom of the product tube 105 so as to keep from interfering with the filling of the product.
As illustrated, the bumper 502 is below the exit of the second funnel 103, below the receiving end of the third funnel 104, but above the exit of the third funnel 104. This location will prevent product simultaneously deposited on opposite sides of the second funnel 103 from colliding with itself. As discussed, this reduces breakage. Furthermore, because the product exiting the second funnel 103 encounters the bumpers 502 and consequently has reduced momentum, the strength of any incidental collisions with the impact point 108 is decreased. It should be noted that while the entire bumper 502 is illustrated as being beneath the exit of the second funnel 103, in other embodiments just a portion of the bumper 502 will extend beyond the exit of the second funnel 103.
In another embodiment, the bumper 502 extends below and beyond the exit end of the third funnel 104. This position presents a physical barrier which prevents product from colliding with the impact point 108. Thus, referring to
Because the extent of the product contact with the bumpers 502 effects the maximum throughput, in one embodiment, the ratio of the inner diameter of the product tube 105 to the outer diameter of the bumper 502 is between about 5:1 to about 1.1:1. The outer diameter of the bumper 502 is measured as the mean diameter of the bumper. With these ratios, the product has sufficient room to be absorbed by the bumper 502 without undesirably slowing or stopping the flow of product through the product tube 105. It should be noted that the bumper size is typically dependent on product size, shape, density, as well as bumper flexibility.
In one embodiment, the bumper 502 comprises individual strands of pliable material which absorb the momentum of the product which falls upon the bumper. The number, size, and strength of these strands depend on the size, density, etc. of the product being packaged, but Applicants have found that thin plastic strands have performed successfully. The strands may also be from a nylon sheet, engineered plastics, rubbers, and other flexible material.
It should be noted that while the strands 502 of the figures are “flared” or “curled,” the instant invention is not so limited. In other embodiments the strands are not flared but are instead straight or substantially shape. Those skilled in the art will appreciate that the geometry of the strands can be optimized for optimal handling of product with depending on the product shape, density, size, etc.
An alternative to the bumper 502 comprising individual strands is a bumper 502 comprising a soft pillow structure (not depicted). In such an embodiment, the product encounters the bumper 502 and a portion of the momentum is absorbed by the pillow structure of the bumper 502. Thus, the pillow structured bumper 502 works similar to the embodiment comprising individual strands except rather than a pliable strand individually absorbing a portion of the momentum of the product falling from the upstream funnel, the entire body of the pillow structured bumper 502 absorbs the momentum. Those skilled in the art will appreciate how to optimize the bumper 502 to absorb sufficient momentum to prevent breakage without slowing or stopping the flow of the product unnecessarily. The pillow structured bumper 502 may be filled with air or another cushion. Further, the bumper 502 may comprise either a filled or hollow tube structure. Regardless of the embodiment, the bumper 502 reduces the momentum of the product and accordingly reduces breakage of the product before it is filled into a package. Advantageously, in one embodiment the bumpers 502 require no mechanical energy to operate which reduces the operating costs of the apparatus.
To reduce product breakage in a filing apparatus product is first introduced into a funnel. A portion of the product momentum is then absorbed by a bumper which is in substantially the same vertical plane as the upstream funnel, and wherein at least a portion of the bumper is located below the exit end of the funnel. Thus, a novel and non-obvious method for reducing the breakage of a product in packaging has been described.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
