METHOD AND APPARATUS FOR PRODUCING LAMINATED PRODUCTS

Abstract: A method and apparatus for producing laminated pro­ ducts, such as candy, is disclosed. The method includes the steps of continuously forming a semifluid sheet of a first material on a longitudinally extending conveyor, depositing a semifluid second material on the sheet of the first material, continuously rolling the sheet from the edges thereof inwardly to form a double roll extending longitudinally along the con­ veyor, and flattening the roll into a laminated sheet product. The method further includes the steps of forming the sheet into a «rope» of substantially smaller width than the sheet by fold­ ing the sheet over itself from the edges of the sheet and allow­ ing the rope to move transverely across a slower mowing con­ veyor so that the rope bunches up on the conveyor. The rope is then flattened by a roller. The method also includes the step of causing the sheet to longitudinally fold over itself so as to form laminations. Additionally, the method includes the steps of divinding the laminated sheet product into longitudinally ex­ tending strips and transversely dividing the strips into indi­ vidual product pieces. Apparatus for achieving the method is also disclosed.

Description: BACKGROUND OF THE INVENTION The present invention relates to the manufacture of laminated products having many layers, and, more particularly but not exclusively, to the manufacture of laminated food products, such as candy, which are formed by the layering of a smooth nonabsorbent material and a soft flowable material. For many years, candy bars have been manufactured which have a crisp texture together with a strong flavor component associated with a soft material. This combination of texture and taste has been achieved by producing a laminate which contains many thin layers of a brittle candy separated by thin layers of the soft flavor material. These candy bars are conventionally made by a labor intensive process that produces inconsistent results. In the prior art process, a hot solution of corn syrup and sugar is dropped on a circular chilled table. A pair of scrapers work the solution by drawing it from opposite outer edges of the table toward the center, the table turning about 1/8 turn between successive scraper operations. As the solution cools, it turns into a soft pliable taffy. Color and flavor ingredients, in liquid form, may be added to the taffy by pouring it into a depression formed in the taffy mass. The taffy mass is manually folded to cover and close the depression. The mass is then manually lifted onto the hooks of a taffy puller. The puller works the taffy, aerating it to reduce its density. The aerated taffy is transferred from the puller to a conveyor and is fed between rollers to form a thin sheet. A layer, for example, of hot peanut butter is applied to the sheet and the sheet is severed at predetermined intervals. Each section of sheet is rolled into a log weighing about 80 lbs (36.3 Kg). The log is folded in half, fed between rollers and rolled out into a sheet once more. This sheet is again rolled into a log which is manually wrapped in a sheet of taffy to keep peanut butter from squeezing out the ends and to provide and ensure that the product pieces have an outer sheet of candy with no exposed peanut butter. The log is manually placed in one of a number of spinning machines that feed a conveyor. The spinning machines have several long rotating cones provided with traction knobs and are positioned on axes that converge toward the output end. The cones are spaced to receive the log and are rotated to draw the log toward the output end and thus stretch the log into a rope about 1/5 its original diameter (from about 5 inches (12.7 cm) diameter to about 1 inch (2.54 cm) diameter). The ends of the rope are manually fed onto a conveyor which carries a number of ropes each formed by a separate spinner. The ropes are divided into product sized bars and enrobed with chocolate. The sheet of taffy in which the log is wrapped forms a taffy wall at each end of the log. As these end portions are stretched out to form the rope, they produce rope sections containing unlaminated taffy. This results in undesirable hard spots in the candy bars. UK Patent Application GB-A-2128130 describes apparatus in which a dough strip is continuously withdrawn from the surface of a baking drum past guides which cooperate with the strip between its edges to fold the strip into various configurations. The folded strip is used to make hollow bodies by an embossing technique. European Patent Application EP-A-130446, which was published on 9th January 1985 and thus after the priority date of the present application, concerns a method of constructing a plastic rope used in the manufacture of hard bonbons with a stratified core that is made out of multiple layers of plastic sugar and plastic filling. Two ropes are treated independently of one another to provide sheets of predetermined thickness and width. Plastic filling is constantly applied to at least one of the sheets in spaced longitudinal lines and the lines of filling are rolled into it from the side in such a way as to produce a tube that is closed into itself and that, after being dimensioned, is pushed along laterally into the other sheet of plastic coating with the edges overlapping in such a way that they adhere together. SUMMARY OF THE INVENTION An aim of the present invention is to provide a method and apparatus for continuously producing uniform products that are composed of alternate layers of different materials. It is a further aim to provide a method and apparatus which has particular application in the manufacture of laminated candy products made of alternating layers of hard and soft materials. According to one aspect, the present invention provides a method for producing a laminated sheet product comprising the steps of continuously forming a semifluid sheet of a first material on a moving conveyor, continuously depositing a second material onto the sheet of first material to form a layered sheet of the first and second materials, continuously rolling the layered sheet from the edges thereof inwardly to form a double roll extending longitudinally along the conveyor and flattening the roll to form a laminated sheet. In order to produce individual commercial product sized pieces, the laminated sheet is then divided into longitudinally extending strips and the strips are then cut transversely into individual pieces. According to another aspect, the invention provides an apparatus for producing a laminated sheet product having alternating thin layers of a semifluid first material and a semifluid second material comprising longitudinally extending conveyor means, means for continuously forming a semifluid sheet of the first material on the conveyor means, means for continuously depositing the second material on the sheet to form a layered sheet of first and second materials, means for continuously rolling the sheet from the edges thereof inwardly to form a double roll extending longitudinally along the conveyor means and means for flattening the roll into a laminated sheet product. Other optional features and advantages of the present invention will be apparent from a reading of the sub-claims and the detailed description which follows. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention have been chosen for purposes of illustration and description, and are shown in the accompanying drawings forming a part of the specification, wherein: FIGS. 1A to 1E provide a top plan view of apparatus according to the present invention when laid out end to end in sequential order; FIGS. 2A to 2E provide a front elevational view of the apparatus shown in FIGS. 1A to 1E when laid out end to end in sequential order; FIG. 3 is a sectional view of the product on the conveyor taken along line 5-5 of FIG. 1A; FIG. 4 is a sectional view of the product taken along line 6-6 of FIG. 1C; FIG. 5 is a sectional view of the product taken along line 7-7 of FIG. 1C; FIG. 6 is a sectional view of the product taken along line 8-8 of FIG. 1C; FIG. 7 is a sectional view of the product taken along line 9-9 of FIG. 1C; FIG. 8 is a top plan view of a modification usable in place of a laterally oscillating chute or conveyor; and FIG. 9 is a front elevational view of the apparatus of FIG. 8. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, there is shown in FIGS. 1A -1E and 2A-2E one embodiment of apparatus according to the present invention in which a cooking and aerating unit 10 continuously produces a stream of a hot aerated solution of corn syrup and sugar, discharging the stream through a nozzle 11 onto a steel band conveyor 12. The unit 10 may be one of the type manufactured by the Otto Hansel company of Germany and sold under the trade name SUCROLINER. The solution exiting from the nozzle 11 is at about 258°F (125.6°C) and is in a very liquid state. A water cooling unit 14 is provided below the upper run of the conveyor 12 to cool the solution to a working temperature between 160°F (71°C) and 200°F (93°C), at which temperature the solution is in a plastic state. The cooling unit 14 sprays water on the bottom surface of the upper run of the conveyor band. The temperature of the spray water varies from about 160°F (71°C) near the input end of the conveyor 12 where the solution is hottest to about 120°F (49°C) near its output end. The stream of solution discharged from the nozzle 11 is immediately spread across the conveyor 12 by a spreader 15 to form a sheet of candy. Ground candy scrap, commonly referred to as "rework", is sprinkled onto the sheet from a vibratory feeder 16 and melts into the hot sheet. A pair of plough blocks 17 (which are suspended from an overhead framework not shown) engage the edges of the candy sheet and fold the edges over onto the center as shown in cross section in FIG. 5. The plough blocks 17 may be rectangular blocks of plastic or metal which are formed with a concave surface 19 for engaging and folding over the candy sheet. The folded sheet exiting from the first set of plough blocks 17 is rolled down and stretched by a cleated roller 20. The sheet exiting from the roller 20 is again folded by a pair of plough blocks 21 and then rolled and stretched by a second cleated roller 22. The narrow thick sheet or rope of candy leaving the roller 22 is then turned over twice, as shown in FIGS. 1B and 2B, by single plough 24 and 25 spaced further along the conveyor 12. The folding and turning of the candy sheet by the plough blocks 17, 21, 24 and 25 allows the candy to cool evenly and prevents excessive cooling of one surface which would result in hardening or "skinning over" of the surface. Referring now to FIGS. 1C and 2C, at the end of conveyor 12, the rope of candy is transferred onto an oscillating chute 26, and from that chute onto a second conveyor 27 which is traveling at a slower rate than the conveyor 12. The chute 26 oscillates about a vertical axis centrally placed at the input end of the chute. The chute 26 narrows toward its output end and is provided with side walls 29 to direct the flow of the candy rope. The chute 26 is mounted on a vertical shaft 30 which is oscillated about its axis by a motor 31 through a crank 32 on the shaft of the motor, an arm 34 on the shaft 30 and a link 35 interconnecting the crank 32 and the arm 34. The oscillating motion of the chute 26 causes the candy rope to be laid down in a sinuous pattern on the slower moving conveyor 27. A pair of guide plates 36 (supported by an overhead framework not shown) confine the folds of the candy rope allowing them to build up in front of a smooth sheeting roll 37. The sheeting roll 37, operating against a backing roll 39 beneath the conveyor belt, rolls the accumulated candy mass into a thin candy sheet. This sheet is operated upon by a scoring roll 40 which is formed with two sets of helical ridges (a lefthand set and a right hand set) extending outwardly from the center of the roll. The roll 40 turns at the same speed that the candy sheet is moving and impresses into the candy sheet a "herring-bone" pattern comprising a series of "V" shaped grooves 41 pointing in the direction the sheet is traveling, as shown in FIG. 1C. Immediately after the roll 40, hot liquefied peanut butter, for example, may be dispensed onto the candy sheet. The peanut butter is pumped from a unit 42 to a pipe 44 that extends across the conveyor 27 and is provided with a number of dispensing nozzles spaced across the candy sheet. The peanut butter is spread with a spreader 45 across the candy sheet and into the grooves 41, as shown in cross section in FIG. 6. The sheet is then rolled from each edge toward the center of the sheet by a pair of sidewinder units 46, each of which contain a serrated roller 47. The units 46 are positioned at each side of the conveyor 27 and the rollers 47 extend over the conveyor at an inward angle from the direction of conveyor travel. The rollers 47 engage and lift the edges of the candy sheet and roll them toward the center to form a double jelly roll configuration as is shown in cross section in FIG. 7. The grooves 41, because of their orientation, aid in the rolling process. They also act as receptacles to hold the peanut butter within the double roll configuration and thus prevent the peanut butter from squeezing out as the roll is formed. The double rolled sheet is rolled down by a cleated roller 49 to form a laminated thick sheet as shown in cross section in FIG. 6. This sheet is folded in half by a plough block 50 to form a laminated rope as shown in cross section in FIG. 7. This rope is rolled out into a relatively thick laminate by a cleated roller 51 as shown in FIGS. 1D and 2D. The thick sheet moves from the end of the conveyor 27 through a swing laminator 52 onto a conveyor 54. The laminator 52 includes a substantially vertical plate 55 positioned under the outlet end of the conveyor 27. The plate 55 is pivoted at its upper end about a horizontal shaft 56 and is oscillated by means not shown, to move in an arc as shown by the arrows and thereby repeatedly fold the candy sheet back on itself, placing one layer of laminate upon another. The number of these layers in the sheet produced by the laminator 52 is controlled by the rate of oscillation of the plate 55 and the speed of the conveyor 54 relative to that of the conveyor 27. However, typically three layers of laminate are combined in this manner so that the number of layers of peanut butter and candy are tripled. A pair of side wall guide plates 57 are provided to keep the layers in alignment, one with another. The laminated sheet is rolled down in three successive stages by cleated rollers 59, 60 and 61. The rolled out thin sheet is transferred to a conveyor 62 and is rolled out further by a sheeting roll 64. This thin sheet is then rolled inwardly from both edges by a second pair of sidewinders 65 to produce another double jelly roll configuration and once again multiply the number of layers of peanut butter and candy in the final product. Each time the number of layers are increased and the sheet is rolled out again, the individual layers become thinner, giving the product a more delicate nature. At the end of the conveyor 62, as shown in FIGS. 1E and 2E, the double rolled sheet is rolled down by a cleated roller 66 and the rolled down sheet is twisted 180 degrees and fed onto a conveyor 67 disposed beneath the conveyor 62. This twisting action can be accomplished by plow blocks, for example, similar to the plow blocks 24 and 25 shown in FIGS. 1B and 2B. The sheet is then rolled out in three successive stages by cleated rollers 69, 70 and 71. The reason for twisting the sheet is that at least part of the bottom surface of the candy may have been continuously against the conveyor and may not have been directly subjected to the stretching and working action of the cleated rollers. Therefore the bottom candy layer of the laminate is thicker and denser than the other layers are at the point of the 180 degree twist. The rollers 69, 70 and 71 stretch and thin this layer to make the laminate more uniform throughout its cross section. The laminate is then transferred to a conveyor 72 and is rolled to its final thickness by sheeting rolls 74 and 75. The sheet is longitudinally grooved by a pre-form roller 76 to facilitate cutting. The preformed sheet moves off the conveyor 72 and between a slitter roll 77 and a back up roll 79. The preformed sheet is longitudinally cut by the slitter roll 77 which has a plurality of thin cutting blades 80. To ensure complete severing of the sheet, the back up roll 79 may be provided with slits to receive the tips of the cutting blades. The separated product strips are given their final cross-sectional shape by a shaping roll 81. The product strips may then be cut into product sized lengths and enrobed or encapsulated with chocolate. In FIGS. 8 and 9 there is disclosed an arrangement which could be used in place of the oscillating chute 26 of the first embodiment, shown in FIGS. 1C and 2C, or in place of the pivoted conveyor 94 of the second embodiment, shown in FIGS. 3C and 4C. In the arrangement of FIGS. 8 and 9, diverging vertical guide walls 129 are provided prior to the sheeting roll 37 and the speed of the conveyor 27 is adjusted with respect to that of conveyor 12 to create a piling up of candy mass in front of the sheeting roll 37, much as shown in FIGS. 1C and 3C.

Claims: A method for producing a laminated sheet product having alternating thin layers of a semifluid first material and a semifluid second material comprising the steps of continuously forming a sheet of said first material on a longitudinally extending conveyor means, continuously depositing said second material upon said sheet to form a layered sheet of said first and second materials, continuously rolling said sheet from the edges thereof inwardly to form a double roll extending longitudinally along said conveyor means and flattening said roll into said laminated sheet product. The method recited in claim 1, further comprising the step of folding an upstream sheet of said first material, or a downstream laminated sheet, from an edge thereof over at least part of itself to form a rope having a width less than the width of the sheet. The method recited in claim 2 wherein said rope is folded over so as to provide even cooling of the surfaces of said rope. The method recited in claim 2, further comprising the step of transferring said rope from a first conveyor means to a second slower moving conveyor means to cause said rope to move in alternate first and second directions transverse to said second conveyor means. The method recited in claim 4, further comprising the step of transversely guiding the rope in said alternate first and second directions. The method recited in claim 5, further comprising the step of flattening said rope after said step of transferring. The method recited in claim 2 wherein said step of folding is performed prior to said step of depositing. The method recited in claim 2 wherein said step of folding is performed after said step of depositing. The method recited in claim 1, wherein said step of depositing comprises the step of forming a plurality of grooves in said sheet of said first material angularly across at least part of said sheet and spreading said second material into said grooves. The method recited in claim 9, wherein said step of forming a plurality of grooves comprises forming a first group of angularly extending grooves from a first edge of said sheet and forming a second group of angularly extending grooves from a second edge of said sheet to form a herring-bone pattern. The method recited in claim 1, further comprising the step of moving a laminated sheet at a first rate on a first surface, transferring said sheet to a second lower surface and moving said sheet on said lower surface at a slower second rate whereby said sheet alternately folds over at least part of itself in first and second longitudinal directions. The method recited in claim 11, further comprising the step of guiding said sheet when it descends from said first surface to said second surface in said alternate first and second longitudinal directions. The method recited in claim 12, further comprising the step of guiding said sheet on said second lower surface in a direction parallel to the longitudinal direction of said sheet. The method recited in claim 12, further comprising the steps of rolling said sheet from the edges thereof inwardly a second time to form a second double roll and flattening said second double roll. The method recited in claim 1, further comprising the step of twisting said double roll. The method recited in claim 1, wherein said second material is softer than said first material. The method recited in claim 16 wherein said first material is a water based material and said second material is an oil based material. The method recited in claim 17 wherein said first material is a candy and said second material is a paste of oil bearing vegetable material. The method recited in claim 1, further comprising the steps of dividing said laminated sheet product into longitudinally extending strips. The method recited in claim 19, wherein said step of dividing said laminated sheet product into longitudinally extending strips comprises the steps of providing longitudinally extending grooves in said sheet product and cutting said sheet product along said longitudinally extending grooves to form said strips. The method recited in claim 20, further comprising the step of transversely dividing said strips into product pieces and allowing said product pieces to harden. Apparatus for producing a laminated sheet product having alternating thin layers of a semifluid first material and a semifluid second material comprising: longitudinally extending conveyor means (27); means (37, 39) for continuously forming a sheet of said first material on said conveyor means; means (42, 44) for continuously depositing said second material on said sheet to form a layered sheet of said first and second materials; means (46, 47) for continuously rolling said layered sheet from the edges thereof inwardly to form a double roll extending longitudinally along said conveyor means; and means (64) for flattening said roll into a laminated sheet product. The apparatus recited in claim 22, further comprising means (17, 21; 65) for folding an upstream sheet of said first material, or a downstream laminated sheet, from an edge thereof over itself to form a rope having a width less than the width of the sheet. The apparatus recited in claim 23, wherein said conveyor means (27) is a downstream conveyor means and there is a faster moving upstream conveyor means (12) disposed in longitudinal alignment therewith on which said rope is formed, and further comprising means (26) for transferring said rope from said upstream conveyor means (12) to said second downstream conveyor means (27) whereby said rope is caused to move in alternate first and second directions transverse to said downstream conveyor means (27). The apparatus recited in claim 24, wherein said transferring means (26) comprises means for transversely guiding the rope in said alternate first and second directions. The apparatus recited in claim 25, wherein said means (26) for transversely guiding comprises inclined ramp means having vertically extending side walls (29) defining a mouth and an exit port of substantially smaller width than said mouth, oscillating means (31, 32, 35) and means (30, 34) coupling said oscillating means to said inclined ramp means (26) to cause said ramp means to move in said alternate first and second directions. The apparatus recited in claim 26, wherein said sheet-forming means (37, 39) flattens said rope. The apparatus recited in claim 23, wherein said means (17, 21) for folding is disposed ahead of said means (42, 44) for depositing on said conveyor means. The apparatus recited in claim 23, wherein said means (65) for folding is disposed after said means (42, 44) for depositing on said conveyor means. The apparatus recited in claim 22, wherein said means (42, 44) for depositing comprises means (40) for forming a plurality of grooves (41) in said sheet of said first material angularly across at least part of said sheet and means (45) for spreading said second material into said grooves. The apparatus recited in claim 30, wherein said means (40) for forming a plurality of grooves comprises means for forming a first group of angularly extending grooves from a first edge of said sheet and means for forming a second group of angularly extending grooves from a second edge of said sheet to form a herring-bone pattern. The apparatus recited in claim 31, wherein said means (40) for forming a plurality of grooves comprises grooved roller means. The apparatus recited in claim 22, wherein said conveyor means comprises a first conveyor (27) having a surface for moving a laminated sheet at a first rate and a second conveyor (54) having a lower surface for moving said sheet at a second slower rate, and further comprising means (52) for transferring said sheet from said first conveyor surface to said second conveyor surface, whereby said sheet alternately folds over at least a part of itself in first and second longitudinal directions. The apparatus recited in claim 33, further comprising means (55, 57) for guiding said sheet when said sheet descends from said first conveyor surface to said second conveyor surface in alternate first and second longitudinal directions. The apparatus recited in claim 34, further comprising means (57) for guiding said sheet on said second lower surface in a direction parallel to the longitudinal direction of said sheet. The apparatus recited in claim 35, wherein said means (57) for guiding said sheet in a direction parallel to the longitudinal direction of said sheet comprises vertically extending wall means. The apparatus recited in claim 34, wherein said means (55, 57) for guiding comprises substantially vertically disposed pivoting plate means (55), said plate means being arranged to move in said first and second alternate longitudinal directions and to engage said sheet when said sheet descends from said first conveyor surface to said second conveyor surface, whereby said sheet is caused to alternately fold over at least a part of itself. The apparatus recited in claim 34, further comprising additional means (65) for continuously rolling said sheet from the edges thereof to form a second double roll extending longitudinally along said conveyor means and means (66) for flattening said second double roll. The apparatus recited in claim 21, further comprising means (76, 77) for dividing a laminated sheet into longitudinally extending strips. The apparatus recited in claim 39, wherein said means (76, 77) for dividing said laminated sheet into longitudinally extending strips comprises means (76) for providing longitudinally extending grooves in said sheet and means (77, 80) for cutting said sheet along said longitudinally extending grooves to form said strips. The apparatus recited in claim 40, further comprising means for transversely dividing said strips into product pieces. The apparatus recited in claim 21, wherein said means (46, 47) for continuously rolling said sheet from the edges thereof comprises longitudinally grooved roller means (47) disposed angularly across at least part of said conveyor means (27).

Inventors: POLIFRONI, NICHOLAS, SIMELUNAS, WILLIAM
Applicants: SOCIETE DES PRODUITS NESTLE S.A.
Application year: 1985
Main classification: A23G3
IPC codes: A23G3, A23P1