Abstract:
The process for making a shaped snack chip uses various components to form a chip having depth such as a bowl-shaped tortilla chip. The chips are formed by sheeting into an initial flat shape. The chips are then passed along for shaping by a mold and plunger conveyor. Once plunged to the mold shape, the chips are reduced in moisture content by baking and frying. After frying, oil is evacuated from the chips whereafter salt and flavoring is applied, if desired, prior to being packaged.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to an improved process for making a shaped snack chip and, in particular, to a process for making a scoop-shaped snack chip. The process allows shaped snack chips to be made at a relatively high production rate with reduced production costs. 
     2. Description of Related Art 
     Snack chips and other food products are frequently made to assume a desired shape. Often, these shapes are merely ornamental in design to assume an interesting shape that appeals to consumers. Sometimes, snack product shapes assume a utilitarian function. One such function is to retain liquid mixtures such as dip, salsa, bean dip, cheese dip, and the like. 
     When a consumer chooses to eat a chip with dip, the consumer typically holds a single chip and immerses a portion of the chip into the dip. The consumer then transfers the dipped chip to his mouth for eating. Often though, the desired quantity of dip fails to adhere sufficiently to the chip or is lost during the transfer process. This problem is particularly noticeable when the chip is flat or relatively flat. Additionally, round or triangular flat chips are often too large to insert into a jar or fail to retain a sufficient quantity of dip on the chip surface during removal of the chip from the jar. With traditional chips, some are too large to consume in one bite. When this occurs, the dip on the uneaten portion of the chip frequently slides off creating a mess and a dissatisfied consumer. 
     To help retain dip, snack chips have been made with curved surfaces. Shaped snack chips allow the consumer to scoop up a desired portion of dip without losing a significant quantity during transfer to the mouth for eating. Further, shaped chips are more maneuverable for insertion into ajar or can of packaged dip such as salsa. The utilitarian shapes known include for example ridges, scoops, taco-shaped, spoon-shaped, and bowl-shaped. Of these, a bowl-shaped chip is particularly desirable as it has a retaining wall or edge surrounding the entirety of the chip. 
     The process for making a shaped chip, especially a bowl-shaped chip, is more complex as compared to traditional flat chip manufacturing processes. With traditional chip production, the dough or masa is extruded or sheeted into a desired chip shape. The shaped chips are toasted to add some stiffness prior to frying. To equilibrate moisture, the toasted chips are passed through a proofing stage. After proofing, the chips are transferred to a fryer for dehydration of the product for consumer packaging. As the chips have a relatively flat shape, no shaping systems are needed or required after the chips are extruded or sheeted. 
     For making a shaped snack chip, an alternative process is shown in U.S. Pat. No. 6,129,939 to Fink et al. A form fryer produces a shaped snack chip by placing chips into a bowl-shaped mold cavity and frying the chip therein. Form frying however requires a specialized dedicated fryer where a fryer is manufactured specifically to handle the molds. A fryer such as this is more complex and has a relatively lower manufacturing capacity compared to a free fryer. A stream of hot oil is used to retain chips in the molds. A cascading oil assists in maintaining the chips in proper position. With this process, a higher oil quality is needed because the oil turnover rate is longer than the typical frying process which causes increased oil degradation over time. A higher oil quantity extends shelf life and improves flavor of the finished chips. 
     Consequently, a process for forming a shaped snack chip that can operate at a high production capacity is desired. Such a process should be capable of producing shaped snack chips while keeping the costs associated with the chip manufacturing equipment and production within industry standards. 
     SUMMARY OF THE INVENTION 
     The present invention is an improved process for producing a shaped snack product such as bowl-shaped tortilla chips. The invention utilizes a sheeter for forming a sheet of dough (masa) into pieces that is fed to a toaster via a conveyor. The essentially flat shaped pieces, which for example could be hexagonal shaped pieces, are fed into one or more high temperature toasting ovens to add rigidity to the chips for the steps to follow. After toasting, the partially dried chip is conveyed to a piece alignment system. The piece alignment system aligns the chips prior to a plunger and mold conveyor system, which provides shape to the chips. The piece alignment system comprises a series of belts whereby the ranks (rows) of chips can be adjusted for proper placement for the plunger and mold conveyor. After the product is plunged in the mold conveyor, the chips pass through at least one oven for reducing chip moisture and providing additional rigidity for frying. Thereafter, the chips are ejected from the molds and are inputted into a fryer where the chips attain their final packaging moisture. Following frying, the chips are passed through an optional salter where salt and/or flavoring is added. The chips are then passed along for packaging for consumers. Particularly, the process is designed to have a high production rate while avoiding the use of rate limiting equipment. The above as well as additional features and advantages of the present invention will become apparent in the following written detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic perspective view of a system for making shaped snack products; 
     FIG. 2 is a side elevation view of a shaped snack chip produced in accordance with the invention; 
     FIG. 3 is a schematic side elevation view of the toaster and piece alignment system portion of the system shown in FIG. 1; 
     FIG. 4 is a schematic elevation view of the toaster, piece alignment system, and plunger and mold conveyor portion of the system shown in FIG. 1; 
     FIG. 5 is a schematic plan view of the alignment belt of the piece alignment system of the system shown in FIG. 1; 
     FIG. 6 is a schematic perspective view of a sensor array of the piece alignment system of the system shown in FIG. 1; 
     FIG. 7 is a schematic perspective view of the piece alignment system and plunger and mold conveyor portion of the system shown in FIG. 1; 
     FIG. 8 is a schematic perspective view of the plunger and mold conveyor of the system shown in FIG. 1; 
     FIG. 9 is a schematic perspective view of mold racks in accordance with the invention; 
     FIG. 10 is a schematic elevation view of a plunger belt in accordance with the present invention; 
     FIG. 11 is a schematic perspective side view of a plunger in accordance with the present invention; and 
     FIG. 12 is a schematic perspective bottom view of a plunger in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION 
     In FIG. 1, a process for forming a shaped snack chip is shown. Sheeter  10  forms a sheet of dough that is fed to toaster  30  via conveyor  20 . Conveyor  20  transfers the essentially flat shaped raw chips, which for example are hexagonal shaped chips. The flat shaped dough or chip is then fed into a high temperature toasting oven  30  for adding rigidity for the following steps. The partially dried chip is then fed to a piece alignment system  40 . The piece alignment system  40  aligns the product for feeding to a plunger and mold conveyor  60 . Plunger and mold conveyor  60  imparts a shape to the chips. After the product is plunged to the mold shape, the chips pass through a multizone dryer  100  for reducing chip moisture. Thereafter, the chips are ejected from the molds and are fed into a fryer  110  where the chips attain their final packaging moisture. Following frying, the chips are passed through an optional salting drum  116  where salt and/or flavoring is added. Thereafter, chips  200  shown in FIG. 2, capable of retaining a liquid mixture are passed along for packaging for consumers. 
     In one embodiment, sheeter  10  has sheeter rollers and a conveyor  20  mounted in a common frame as a single unit (not shown). Sheeter  10  receives the dough at an inlet. The dough can be comprised of corn, wheat, rice, or other grains and mixtures thereof. For the preferred embodiment, the dough is comprised of white dent corn. As the sheet is formed in sheeter  10 , a cutter within sheeter  10  having the initial chip shape, which for example is an essentially flat hexagon, is provided. As dough passes by a cutter within sheeter  10 , the initial chip shape is formed so that essentially flat chips  202  being produced have approximately the same shape and thickness upon exiting sheeter  10 . Chips  202  are conveyed over conveyor  20  towards toaster  30 . Optionally, conveyor  20  has a pneumatic lift system to raise the conveyor to provide access to toaster  30  as needed. This is beneficial because as formed product exits sheeter  10  the product essentially drops a small distance onto conveyor  20 . As the physical properties of the product being sheeted may change such as the coarseness and particle size of the dough, the adhesive properties, and the moisture content, the ability to adjust this drop is beneficial to maintain product uniformity. 
     After the dough is sheeted into the chip product&#39;s initial shape, chips  202  are fed to toaster  30  for reducing the product moisture. The chip moisture leaving the sheeter is typically about 50 to about 52% and is reduced to about 30 to about 40% by toaster  30 . Chips  202  are dropped onto a rotating transfer belt  32  for passage through toaster  30 . Toaster  30  toasts chips  202  through heating with infrared (IR), radio frequency, convective, ribbon burners, direct gas fired, conductive, impingement, and microwave heating for example. In a preferred embodiment, a series of IR burners or direct flame belt heaters are used. After toasting, chips  202  are transported to piece alignment system  40 . 
     Preferably, the product coming forth from toaster  30  just prior to a piece alignment system  40  utilizes a bladeless transfer shown in FIGS. 3 and 4. Unlike with a bladed transfer, a bladeless transfer avoids having multiple chips adhering to the blade due to sticky residue buildup thereon, nicks in the blade from high force contact with the toaster oven belt, blade replacement, or the blade losing contact with the belt causing chips to be captured between the blade and toaster oven belt. With the bladeless transfer, a monolayer of product leaving toaster  30  is maintained more readily than with using a conventional blade assisted transfer, i.e., a doctor blade. The blade assisted transfer does not require precise spatial orientation because a doctor blade is not practical for a molding process. To achieve bladeless transfer, the terminal end of toaster oven belt  32  has a discharge roll  38  that is disposed higher than a transfer belt  42 , about 0.2 to about 0.5 inches higher. The leading edges of the toasted chips  202  essentially lift off of toast oven belt  32  at discharge roll  38  and convey onto transfer belt  42  at a nosebar roll  44 . 
     FIGS. 3 and 4 show transfer belt  42  which is the first of several belts of the piece alignment system  40 . The speed of transfer belt  42  operates at essentially the same rate as belt  32  to facilitate the bladeless transfer. With the product essentially aligned as a monolayer of partially dried chips  202 , these chips  202  are transferred to a phasing belt  46 . Phasing belt  46  has an adjustable speed for transferring chips  202  from the speed on transfer belt  42  to the speed and position needed for mold alignment belt  50 . Once at proper speed, the product is fed to alignment belt  50 . 
     With alignment belt  50 , the chips are aligned by rank (rows) and file (columns) for eventual feeding to a plunger and mold conveyor  60 . Alignment belt  50  has a system for conveying the chips into essentially even ranks. Although the chips entering alignment belt  50  have essentially distinct and even files, the ranks are not sufficiently aligned for eventual feeding to the plunger and mold conveyor  60 . Therefore in one embodiment, alignment belt  50  is outfitted with a series of cleats  52  that extend upwards from alignment belt  50  as shown in FIG.  5 . These cleats  52  are moving slightly faster than alignment belt  50  and are traveling on a cleat conveyor (not shown) disposed beneath alignment belt  50 . 
     As such, most chips are eventually pushed along the moving alignment belt  50  so that at the exiting from alignment belt  50  the chips have essentially even ranks. To maintain even files, it is preferable that at least two cleats  52  be provided per chip  202 . Thereby, a trailing edge of chip  202  will end up disposed between at least two cleats  52 . To catch each chip  202 , the distance between two cleats  52  in a rank is smaller than the width of the chip. Upon exiting alignment belt  50 , chips  202  are deposited on a discharge belt  54  for transfer to mold belt  68  of plunger and mold conveyor  60 . 
     To ensure that the majority of chips  202  passing onwards to the plunger and mold conveyor  60  are in proper alignment, a position control system is utilized with piece alignment system  40 . Further the control system is used to insure that chips  202  are deposited onto alignment belt  50  such that chips  202  will be between rows of cleats  52 . The control system compensates for the differences of the incoming speed of chips  202  being fed into the piece alignment system  40  and the positioning needed for the plunger and mold conveyor  60 . If not positioned properly within a determined acceptable range for the plunger and mold conveyor  60 , then a number of chips  202  will not be positioned properly into the molds of the plunger and mold conveyor  60 . 
     Therefore, a chip sensor  48  is positioned to operate in conjunction with piece alignment system  40 . In a preferred embodiment, chip sensor  48  is positioned above phasing belt  46  and/or discharge belt  54 . However, chip sensor  48  can be positioned at a number of locations along the system for forming a shaped snack chip  202 . An optical sensor such as a photocell array can detect chips  202  to effectively determine their relative position. Other sensors can be employed however such as laser, ultrasonic, cameras, and color contrast. 
     The control system uses the information gathered from chip sensor  48  to determine the average rank position of chips  202  as to whether chips  202  are approaching on target, too early, or too late. Based upon this average computed position, an adjustment to the overall system is made if needed to insure that piece alignment system  40  is delivering essentially uniform ranks of chips to plunger and mold conveyor  60 . To adjust the positioning of the chips, the control system could optionally adjust one or more of the speeds of transfer belt  42 , phasing belt  46 , cleats  52 , and/or discharge belt  54  for optimal chip delivery to plunger and mold conveyor  60 . As to positioning of the sensor, chip sensor  48  could be situated above transfer belt  42 , phasing belt  46 , alignment belt  50  at the chip entry, and/or discharge belt  54 . 
     For example, a photocell array  56 , utilizing chip sensors  48 , is arranged to measure the front wall of the passing chips  202  as they pass on phasing belt  46  as shown in FIG.  6 . The first and last files of these are typically not measured because these end chips  202  tend to accumulate scrap material from upstream processing. Sensing the remaining chips  202 , the average position of chips  202  in that rank can be determined. The speed of phasing belt  46  is then adjusted if necessary to assure that the following ranks of chips  202  will be fed to plunger and mold conveyor  60  at the proper speed to assure maximum alignment of chips  202  being deposited onto molds  64 . 
     FIG. 7 shows plunger and mold conveyor  60  receiving the flat chips  202 . The moisture of chips  202  is at approximately the same moisture as upon their departure from toaster  30 . At this moisture, the chips have enough cohesive integrity for molding. 
     Chips  202  are passed from discharge belt  54  to mold racks  62 . Ranks of mold racks  62  are comprised of a series of connected individual chip molds  64  for imparting the desired shape to each chip  202 . With proper sequencing, each mold  64  receives a chip properly aligned from piece alignment system  40 . Although molds  64  can be of any practical shape for a snack chip, molds  64  preferably have a bowl-shape. 
     FIGS. 8 and 9 show molds  64  that are formed by the juxtaposition of two mold racks  62 . Each mold rack  62  has a series of halves of molds  64  positioned along in ranks. Ranks of mold racks  62  travel continuously about mold belt  68 . Mold belt  68  is timed to ensure that mold racks  62  are properly positioned for receiving the chips into molds  64  and for plunging. For example, a servo driver can properly control the timing of mold racks  62 . In a preferred embodiment, mold belt  68  is a continuous chain belt disposed around rolls as shown in FIG.  7 . As mold racks  62  begin to travel upwards around roll  66 , the top portions of mold racks  62  begin to separate apart due to the physics of having rectangular-like mold racks  62  traveling about a roll. As mold racks  62  reach the top of mold belt  68 , the top portions of mold racks  62  close together thereby forming molds  64 . Similarly, when mold racks  62  complete passage through dryers  100 , molds  64  separate and open for discharging the chips. 
     As shown in FIG. 8, molds  64  have a bowl-shape. Other shapes are possible however such taco, oval taco, hexagonal taco, round saucer, canoe, spoon, oval, round, and more. Molds  64  are preferably only semi-enclosed in order to maximize the exposed surface area of the chip as it is further dried in dryers  100 . Mold racks  62  contain a number of halves of molds  64  such that the juxtaposition of two mold racks  62  on mold belt  68  forms full molds  64 . In the embodiment shown, six halves are disposed within a single mold rack  62  in a rectangular three by two scheme although other schemes are possible. Each half of mold  64  has its closed end towards the middle of mold rack  62 . Linking the mold halves together on mold rack  62  is a mold rack support structure  120 . As depicted in a preferred embodiment, mold rack support structure  120  is a solid mesh structure. This allows now molded chips  200  disposed in mold racks  62  to be exposed to a greater amount of air and heat in dryers  100  as compared to a solid mold rack. Also, less material is required to form mold rack  62  which reduces costs and weight. Typically, mold racks  62  can be formed from any moldable, heat resistant material such as plastic and metal. In the preferred embodiment, mold racks  62  and, therefore, molds  64  are made from stainless steel. 
     FIG. 9 shows a cross section view of a preferred embodiment of mold  64 . Mold rack support structure  120  confines each mold  64 . Within mold  64 , depending support arms  122  extend from support structure  120  downward and inward towards the center of mold  64  to affix to a bottom edge support  124 . Bottom edge support  124  forms a partially open ring to support the shaped snack chip  200 . At a top portion of depending support arm  122 , a plateau edge  126  provides a resting surface for flat chips  202  yet to be plunged. When flat chip  202  is initially deposited into mold  64 , plateau edges  126  support chip  202  over the open space of mold  64 . To help retain chip  202  within mold  62 , one or more barbs or beveled edges can be provided. As shown, optional upper and lower barbs  130  and  132  are disposed towards the top portion of the each depending support arm  122 . Once the chip  202  is pressed into mold  64 , the top edge will likely abut barbs  130  or  132  on several of depending support arms  122 . As chip  202  is stamped into a mold  64 , it assumes the mold&#39;s shape to form chip  200 , which is a hexagon bowl-shape as shown in FIG.  2 . Additionally, the chips can be given additional features of shape by modifying the shape of plunger inserts  80 . Should a chip  202  be misaligned and not completely inserted into mold  64  by a plunger insert  80 , the resulting chip produced will still generally have a scoop or bowl shape, although possibly not centered. This is because a portion of chip  202  will still be contacted by plunger insert  80 . The portion of chip  202  contacted is forced into mold  64  which thereby produces a shaped chip  200 . 
     To reduce the loss of chips not deposited into a mold  64 , an optional feature of retaining chips can be provided. Fingers (not shown) can be provided to prevent a vertically oriented chip  202  from falling through the space between two mold racks  62  should a chip  202  not land into a mold  64 . These fingers are attached to the base portion of mold rack  62  around bottom edge support  124  to extend between mold racks  62 . Thereby, the fingers will support any vertical chips  202  as it travels along plunger and mold conveyor  60  and dryer  100 . While these chips will not be plunged, they are retained to increase the product yield. 
     FIG. 10 shows plunger inserts  80  disposed along plunger belt  82  of plunger mold conveyor  60 . Plunger inserts  80  are typically comprised of a moldable material such as silicone, rubber, plastic, or metal. Softer materials such as silicone, rubber, or plastic are preferred. Insuring that plunger inserts  80  will be aligned above the corresponding opening of mold  64 , mold racks  62  and plungers  80  are carried longitudinally along on mold rack belt  68  and plunger belt  82 , respectively, and are synchronized to operate together. Once chip  202  is disposed properly on mold  64  at plateau edges  126 , a plunger insert  80  extends downward pushing chip  202  into mold  64 . In operation, an individual plunger insert  80  extends into mold  64  for less than one second, generally only about 0.4 seconds. By minimizing the time that plunger insert  80  extends into mold  64  reduces the likelihood of product shearing effects caused from mechanical wear and thermal expansion. Further, minimizing the time reduces the amount of misalignment between plunger insert  80  and mold  64 . 
     FIG. 11 plunger insert  80  has eight fluted edges  84  extending outward from the plunger insert&#39;s central support rod  86 . Fluted edges  84  provides ridges to the chip. With eight fluted edges, molded chip  200  will comprise an essentially octagonal shape after being plunged. In other words, each chip will have eight fluted edges. While plunger insert  80  is shown having eight fluted edges, other quantities of fluted edges are possible depending on the shape of the chip desired. The fluted edges  84  extend from a bottom portion of plunger insert  80  upward towards flange  88  shown clearly in FIG.  12 . Flange  88  is disc shaped and is essentially parallel to plunger belt  82  in operation. The diameter of flange  88  is approximately equal to the inner width of mold  64 . Further, flange  88  extend outward from support rod  86  to approximate the inner width of mold  64 . As shown, fluted edges  84  extend from flange  88  downward towards the bottom of support rod  86 . The bottom periphery of flange, shown in FIG. 12, approximates that of mold  64  while a top portion does not and extends linearly to provide fluted edges  204  to formed chips  200 . Fluted edges  204  allow for a point of entry and easier dipping of the finished chip. Above flange  88 , support rod  86  protrudes upward with plunger mating adapter  94 . Plunger mating adapter  94  provides for the connection of plunger insert  80  to plunger belt  82 . In one embodiment, plunger mating adapter  94  is a screw bolt which is received by a plunger platform  90  that is affixed to plunger belt  82 . 
     Plunger belt  82  rotates above and at the same speed as mold belt  68  for suitable plunging and molding of shaped snack chips  200 . As plunger inserts  80  rotate around on plunger belt  82 , plunger inserts  80  are pressed into molds  64  at desired intervals. For appropriate timing, plunger belt  82  preferably uses a link conveyor arrangement. However, other arrangements are possible such as a walking beam or air piston plungers. With the conveyor arrangement, the plunger belt  82  is driven by a mechanical linkage powered by a support chain connected to mold belt  68 . As a set of plungers  80  rotates towards the desired interval of plunging, a cam mechanism is depressed causing one or more sets of plungers into corresponding molds  64  in a vertical motion. To actuate the cam mechanism, a plunger actuator assembly  96  is provided. After a brief interval, the tension on the cams is released which thereby releases plungers  80  upward and out of molds  64 . In application, two rows of plungers are retained per plunger platform  90 . By having two or more rows per plunger platform  90 , the number of mechanical components is reduced and a structural integrity is improved. 
     Once plunging is complete and chips  200  are passed through plunger and mold conveyor  60 , chips  200  are conducted through a form dryer  100  while still retained within molds. Form dryer  100  is optionally a multizone dryer with four zones that reduces chips  200  down to a desired moisture content so that chips  200  will retain their shape after being ejected from molds  64  into fryer  110 . In a preferred embodiment, the moisture of chips  200  after passing through from dryer  100  will be reduced to between about 23 to about 28%. Dryer  100  are hot air impingement ovens that utilize hot forced air. Other forms of drying however may be used such as infrared, microwave, or radio frequency. Optionally, a vacuum is provided from beneath mold belt  68  within form dryer  100  to aid in drying the chips. With the open structure of mold racks  62 , a relatively large surface area of chips  200  be exposed to the drying currents. In the preferred embodiment, drying is provided at a temperature of about 300 to about 400° F. The chips are reduced from an inlet moisture of about 34 to about 38% to an outlet moisture of about 23 to about 28%. At the end of the form dryers  100 , chips  200  are separated from molds  64  onto a fryer feed belt  112 . 
     To release chips  200 , molds  64  open and separate to allow the chips to continue towards fryer  110 . To assist the release of chips  200 , an air blower beneath mold rack belt  68  can direct a stream of air or other inert fluid towards the bottoms of molds  64 . Since molds  64  are designed to be partially permeable, the air current will push chip  200  from the mold in addition to gravity. The shaped chips  200  are directed onto a fryer feed belt  112  and then into fryer  110  containing oil. 
     Fryer  110  is used to bring the product to its final dryness for consumer packaging and to add flavor. The chip moisture upon entering fryer  110  is about 20 to about 24%. After frying, chip  200  has a moisture content of about 0.8 to about 1.3%, more preferably about 1.1%. Also, the oil content of chip  200  is about 23 to about 25%, more preferably about 24%. The process of frying chips  200  involves feeding chips  202  from belt  112  into fryer  110 . Chips  200  are fed into fryer  110  in a random packing order whereby free-frying occurs. After free-frying, chips  200  are introduced into a paddle section for transferring to a submerger for deeper packing of chips. For evacuating chips  200  from the submerger section, multiple cascading conveyors hoist chip  200  out of the oil. Thereby, chips  200  drain any residual oil from any crevices in chips  200  as they are passed from one conveyor to the next. Chips  200  are then placed onto a fryer discharge belt  114  for feeding to an optional drum  116  or to packaging. Rotating drum  116  provides any salting and/or flavoring that is desired. Thereafter, shaped chips  200  are sent to product packaging. 
     The present process produces a shaped snack chip more efficiently at a relatively high production rate. The present invention is superior to prior art processs of making a shaped snack chip because costly form frying is avoided. The product produced has a desired utilitarian shape useful for scooping and retaining liquid mixtures such as dips and other toppings on the chip. 
     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 changes in form and detail may be made therein without departing from the spirit and scope of the invention.