Method for producing corrugated material

This invention relates to a method for producing corrugated material and processing strip material which is removed from the edges of the corrugated material during the formation process. The strip material is cut away from the corrugated material and expelled at a variable line speed to a trim processing machine. The line speed is measured by a sensor which provides a signal representation of the speed to a cutter assembly. The cutter assembly cuts the strip material at a cutting speed which is sequenced to the line speed such that the strip material is cut into a plurality of pieces. The pieces are generally uniform in shape and size across variations in the line speed as the cutting speed is synchronized with the line speed.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates generally to a method for producing corrugated material. More particularly, the invention relates to a method for forming corrugated material by cutting the edges off the corrugated material into a strip material, and then processing the strip material into smaller pieces at a variable processing speed. Specifically, the invention relates to a method for varying the processing speed in response to variations in the input speed of the strip material, such that the strip material is continuously converted into a plurality of smaller pieces having the same generally uniform shape.

2. Background Information

This invention relates to the process of making corrugated material, forming the material into boxes or other similar commercial products, and processing the waste edge strip material of this process into a new commercial product. Previously, the waste edges of this process were discarded as unusable.

Paper based corrugated material is formed in a corrugator and fed directly into an edge cutter. The edge cutter cuts the corrugated material to a specified width to match the size requirements for the particular commercial product being produced. The edge strip material is cut away and the corrugated material travels on to be formed into the finished product. As the strip material comes out of the edge cutter, it is either fed into a bin for later processing, or fed into a trim processing machine (“trim cutter”) whereby the long narrow pieces are cut into smaller pieces by a blade. After this cutting stage, the cut strip material is collected, baled, and processed as waste by-product of the corrugation process.

Trim processing machines to date include a blade which simply cuts across the width of the strip material at a static interval, regardless of the speed with which the strip material enters the trim processing machine. This static cutting frequency results in large pieces when the strip material moves through the machine at a fast rate, and small pieces when the strip material moves through the machine at a slow rate. Furthermore, trim processing machines and methods to date cannot match the fast line speeds of the corrugator and edge cutter. Therefore the strip material typically is collected after exiting the edge cutter, and later fed into the trim processing machine.

Heretofore, existing trim processing machines and methods have been characteristically inefficient and lacking in processing the waste edge strip material during the formation of the corrugated product. Therefore, the need exists for a trim processing method which can match the fast line speeds of the corrugator so the strip material may be processed at the same time the corrugator is forming the commercial product. There is also a need to cut the strip material at a cutting frequency which is sequenced or matched with the speed of the corrugator line and edge cutter, thereby allowing uniformly sized pieces of the cut strip material to be produced across the entire range of possible input speeds which may dynamically change during operation. The need also exists for a trim processing method which cuts across both the length and width of the strip material to produce cut trim pieces which are smaller than the overall width of the trim.

If a manufacturer of corrugated products could produce a uniformly sized by-product of the corrugation process, regardless of the line speed or width of the strip material, the cut strip material pieces could be resold as a commercial product and used various applications such settings as animal bedding. This represents an enormous improvement in the field, as currently scrap strip material pieces are simply discarded.

BRIEF SUMMARY OF THE INVENTION

This invention focuses on a method for producing corrugated material and processing the strip material expelled as a by-product of the production process at a variable line speed. The method of the present invention utilizes a corrugator having a flute processing device for producing a fluted sheet, and a backer device to apply a liner to the fluted sheet and expel a corrugated material at a line speed. The expelled corrugated material is then received by an edge cutter machine, wherein edge strip material is cut off the edges of the corrugated material. This edge strip material is subsequently fed into a trim cutting machine. The trim cutting machine is generally comprised of a sensor for measuring the line speed, a cutter assembly which is operatively connected to the sensor, and a feeder assembly which is also operatively connected to the sensor. The feeder assembly receives the strip material from the edge cutter machine and conveys the strip material to the cutter assembly at the line speed. The cutter assembly cuts the strip material at a cutting speed into a plurality of pieces having a uniform size and shape and collects the pieces for eventual commercial use. This uniform shape is ensured by varying the cutting speed in response to variations of the line speed. It is readily understood that the edge cutter machine may exist as a sub-machine within the overall corrugator machine, or may exist separately.

The feeder assembly preferably used in the present method has a plurality of first bumpers disposed within a housing, and a plurality of second bumpers disposed within the housing, whereby the first and second bumpers rotationally cooperate to convey the strip material therethrough. The feeder assembly further includes a motor, whereby the motor is operationally connected to the sensor, and the first and second bumpers are rotationally controlled by the motor. The motor then rotates the bumpers to match the line speed and thereby convey the strip material through the housing to the cutter assembly at the line speed.

The cutter assembly preferably used in the present method has at least one rotor having a plurality of blade assemblies disposed thereon, a motor, and an anvil having a teeth portion. The blade assemblies each includes a blade portion complementarily shaped with the teeth portion. The rotor is rotated by the motor at the cutting speed to engage the blade portion with the teeth portion to cut the strip material.

DETAILED DESCRIPTION OF THE INVENTION

The preferred machine for carrying out the steps of processing strip material of the present invention is indicated generally at1, and shown inFIGS. 1-16. The strip material of the preferred embodiment is the waste edge strip material trimmed off the sides of corrugated paperboard during the corrugation process. Hereafter the machine for processing strip material will be referred to as trim processing machine1, as the preferred embodiment relates to the method of manufacturing corrugated products such as boxes and shipping containers, although it is readily understood that it can be other types of materials within the concept of the present invention.

The general machine and system for turning raw materials into corrugated material is shown diagrammatically inFIG. 1. A corrugator3includes a first roll5of paper-based material7which is rotated off first roll5into a flute processing device9in the direction of Arrow A. Flute processing device9forms a flute into material7and outputs a fluted sheet11. Corrugator3further includes a second roll13of paper-based material15which is rotated off second roll13in the direction of Arrow B and into a backer device17along with fluted sheet11. Backer device17adheres material15onto fluted sheet11to form a top liner19on a raw corrugated sheet21. Corrugator3further includes a third roll23of paper-based material25which is rotated off third roll23in the direction of Arrow C and into backer device17. Backer device17adheres material25onto fluted sheet11to form a bottom liner27on raw corrugated sheet21. Alternatively, flute processing device9may form the flute in material7and adhere material15to fluted sheet11in a first apparatus commonly referred to as a “single-liner”, and subsequently adhere material25in a second apparatus referred to as a “double-backer”. It will be readily understood that the machine and system shown inFIG. 1for carrying out the method of the present invention is a simplified diagram of this process.

Raw corrugated sheet21exits backer device17in the direction of Arrow D at a variable speed and comprises a raw corrugated material having a width which corresponds to the width of materials7,15, and25. A sensor26is located proximate backer device17and measures the speed with which raw corrugated sheet21exits the backer device. Sensor26passes the speed information to trim processing machine1through a conductor28. Next, raw corrugated sheet21is fed into an edge cutter29which cuts an elongate pair of trim edges31off raw corrugated sheet21to form a finished corrugated sheet33. Finished corrugated sheet33conforms to the particular width requirement of the intended product, and is carried away by a conveyer belt35or other transport mechanism in the direction of Arrow E for further processing. Trim edges31exit edge cutter29and enter trim processing machine1in the direction of Arrow F. Trim processing machine1performs processing functions therein at a particular speed based on the signal supplied by sensor26through conductor28, and expels a plurality of uniform cut pieces37(FIG. 11) of trim edges31through a duct39. Pieces37travel through duct39into a hopper41where they are collected and stored, and removed as desired by the user.

As shown inFIGS. 2-5, trim processing machine1has a front end44, a back end46, and a feeder assembly43abutting a cutter assembly45, whereby both feeder assembly43and cutter assembly45are secured to a base47. Feeder assembly43includes of a pair of feeder sub-assemblies49A and49B. Feeder sub-assemblies49A and49B are substantially identical, therefore only49A is described in detail. Feeder sub-assembly49A includes an inlet51secured to a frame53and defining an inlet channel52therethrough. Frame53includes a front wall55, a back wall57, and an upper wall59disposed therebetween, whereby front wall55and back wall57are secured to base47. As shown inFIGS. 2 and 10, a roller housing61having a general box-like structure is disposed intermediate front wall55and back wall57and includes an adjustable upper structure63having a top wall65and a side wall67. Roller housing61further includes a non-adjustable lower structure69having a first sidewall71(FIG. 4), a second sidewall73(FIG. 3), and a bottom wall75(FIG. 10) extending therebetween.

Feeder sub-assembly49A further includes an adjustable first roller system77and a non-adjustable second roller system78, both of which are driven by a drive shaft83. Drive shaft83is powered by a drive belt79extending from a drive motor81. Drive shaft83extends the width of sub-assembly49A (FIG. 5) to provide rotational turning force to roller systems77and78. Adjustable roller system77(FIG. 3) is comprised of a plurality of pulleys85and a plurality of attached rollers87mounted on sidewall67. Pulleys85and rollers87are connected to drive shaft83and an adjustable top pulley89by a first belt91. Top pulley89is disposed on an adjustment plate93movably mounted on a beam94extending from top wall59. Pulleys85are mounted on sidewall67and rotate to allow first belt91to pass thereover to maintain tension in first belt91. Each roller87includes a bumper shaft95extending through sidewall67and connected to a bumper97within roller housing61(FIG. 10), whereby rotation of roller87rotates bumper97by way of bumper shaft95.

Non-adjustable second roller system78(FIG. 4) is similar to first roller system79and includes a plurality of pulleys99and a plurality of attached rollers101disposed on first sidewall71. Pulleys99and rollers101are connected to a top pulley103by a second belt105powered by drive shaft83. Top pulley103is disposed on an adjustment plate107movably mounted on beam94. Each roller101includes a bumper shaft109extending through first sidewall71and connected to a bumper111within roller housing61(FIG. 10), whereby rotation of roller101rotates bumper111through bumper shaft109.

A pair of alignment rods90(FIG. 4) are secured to top wall65of upper structure63and extend upwardly through top wall59of frame53. An adjustment rod92(FIG. 11) is secured to top wall65and extends upwardly through top wall53and into an adjustment mechanism96, whereby upper structure63may be raised or lowered to change the distance between bumpers97and bumpers111within roller housing61. As upper structure63is adjusted to change the distance between bumpers97and111, top pulley89of first roller system77adjusts the position on plate93to maintain tension within first roller system77and first belt91.

As shown inFIGS. 3,4,10, and11, feeder sub-assembly49A includes an internal roller channel113which extends from a first end115proximate an opening119formed in front wall55of frame53to a second end117proximate an opening121defined in back wall57of frame53. As shown inFIGS. 3 and 4, motors81rotate drive belts79at a particular speed, sequenced to the line speed, which rotates drive shaft83. Drive shaft83rotates first belt91which rotates pulleys85and rollers87. Drive shaft83also rotates second belt105which rotates pulleys99and rollers101. Rollers87and101rotate bumper shafts95and109, respectively, and in turn rotate bumpers97and111, respectively, within roller housing61. As shown inFIG. 11, bumpers97and111rotate in the directions of Arrows G and H, respectively, to frictionally pull trim edges31into roller housing61. Motor81accepts line speed information from sensor26through conductor28and adjusts the speed with which motor81rotates drive belt79, thereby sequencing the speed with which bumpers97and111pull trim edges31with the line speed.

As shown inFIG. 10, cutter assembly45is secured to feeder assembly43proximate second end117and opening121. As shown inFIGS. 5-7, cutter assembly45includes a motor123, which rotates a drive wheel125to turn a drive belt127and rotate a wheel129secured to a shaft131. Shaft131extends through a rotor housing133from a first side135to a second side137. Drive wheel125, drive belt127, and wheel129are enclosed within a drive housing139.

As shown inFIGS. 5,6, and10, rotor housing133extends from a first end141to a second end143, and includes an anvil mount146proximate first end141and a front wall145defining a pair of cutter apertures147therein. A pair of sidewalls149form the sides of rotor housing133and are secured together by a plurality of tie rods148. A deflector wall152extends from an anvil mount146to a bottom wall150. The upper end of rotor housing133is enclosed by a pair of access panels163removably secured and extending between front wall145and a back wall144to allow access to rotor housing133. Back wall144extends from access panels163to a top back wall154. Top back wall154, sidewalls149, and bottom wall150define a channel158therebetween which aligns with duct39.

As shown inFIG. 7, sidewalls149define a notch151sized to pass shaft131therethrough. Sidewalls149further define a rotation hole153whereby shaft131is sized to rest and slidably rotate therein. A pair of notch caps155cover notches151when shaft131is securely received within rotation hole153. A bearing156is disposed on one end of shaft131, and a bearing157is disposed on the opposite end to facilitate axial rotation of shaft131. A debris shelf161and spacer wall159having a notch162are disposed in rotor housing133. Spacer wall159is generally parallel to sidewalls149, whereby shaft131is fittably and rotatably received in notch162to prevent upward movement.

As shown inFIGS. 5, and11, conductor28provides the line speed information to motor123which controls the rotational speed of shaft131. Motor123controls rotational speed of shaft131by increasing or decreasing the rotational speed of drive wheel125, which turns drive belt127. Drive belt127rotates wheel128which is secured to shaft131and thereby rotates shaft131. As discussed previously, shaft131is supported at each end by bearings156and157which facilitate efficient rotational turning of shaft131by motor123.

As shown inFIG. 8, cutter assembly45further includes a pair of rotors165A and165B. Rotors165A and165B are substantially identical, therefore only rotor165A is described in detail. Rotor165A is secured to shaft131whereby rotation of shaft131rotates rotor165A. Rotor165A includes of a pair of side disks167, each having an inner surface170, an outer surface172, and an outer circular edge166. Each pair of side disks167are held securely together by a plurality of blade assemblies168secured to inner surfaces170of side disks167.

As shown inFIGS. 8-12, each blade assembly168is disposed at a spaced distance apart from one another on rotor165A and extend towards outer edge166of side disks167. Each blade assembly168includes a blade holder169and a blade plate171equal in length to maintain side disks167apart at a desired width. Each blade plate171includes a top surface178and is removably secured to blade holders169along top surface178to allow a user to remove blade plate171through access panels163for maintenance or replacement.

As shown inFIGS. 12 and 13, each blade plate171further includes a plurality of blades173. Each blade173includes an angled front surface182terminating in a cutting edge175, and two side surfaces180, each terminating in a cutting edge176(FIG. 15). Each blade173defines a plurality of recesses174therebetween, whereby blades173and recesses174are arranged in a “sawtooth” pattern. An angled surface184extends between each blade173proximate each recess174, whereby angled surface184terminates in a cutting edge177(FIG. 15).

As shaft131turns, rotors165A and165B turn to pass blades173through a pair of complementarily shaped anvils179as each blade assembly168rotates past anvils179. As shown inFIGS. 12 and 13, each anvil179includes a top surface189and a bottom surface191and is removably secured to stabilizing beam146along bottom surface191(FIG. 7). Each anvil179further includes a plurality of teeth183. Each tooth183includes a front surface190terminating in a front edge185, and two side surfaces194, each terminating in a side edge186. Each tooth183defines a plurality of recesses181therebetween, whereby teeth183and recesses181are arranged in a “sawtooth” pattern. A back surface192extends between each tooth183and proximate each recess181, whereby back surface192terminates in a back edge187.

As shown inFIG. 9, rotor165A includes blade assemblies168A and rotor165B includes blade assemblies168B. Blade assemblies168A and168B are preferably cross-sectionally intermediate one another and preferably spaced cross-sectionally equidistant apart. As each rotor165A and165B turn, blades assemblies168A and168B, respectively, are positioned to pass blades173through recesses181in anvils179in an alternating sequence between blade assemblies168A and168B. Alternating passes from blade assemblies168A and168B reduces the force on anvil mount146as only one blade assembly168A or168B passes through anvil179at a given time, rather than both blade assemblies168A and168B simultaneously.

As shown inFIGS. 12,15, and16, anvil179and blade plate171are complementarily shaped to cut trim edges31into small, generally rectangular pieces37as blades173pass through recesses181in anvil179. Cutting edges176are configured to cut in a generally perpendicular direction to cutting edges175, and cutting edges177are configured to cut in a generally parallel direction to cutting edges175, thus producing the generally rectangular pieces37. As shown inFIG. 15, trim edge31is conveyed over anvil179, whereby at a particular interval, blades plate178plunges through trim edge31, shearing trim edge31against anvil179into pieces37. As shown inFIGS. 13 and 16, cutting edge175of blades173initiates contact with trim edge31as blade plate171rotates on rotor165, whereby trim edge31is punctured by cutting edge175of blades173. Next, as rotor165continues its rotation, cutting edges176of blades173shear trim edge31along side edges186of teeth183. This shearing is performed from proximate back surface192of recess181to proximate front surface190of teeth183. As side shearing is completed, the portion of trim edge31which was conveyed over recesses181in anvil179fall away as separate cut pieces37A (FIG. 14). As shown inFIG. 15, shearing away piece37A forms the leading edge of the next piece37A in succession.

As shown inFIGS. 14 and 16, at generally the same moment cutting edge175of blades173contact back edges187of recesses181, cutting edges177on blade plate171meet front edges185of teeth183on anvil179, shearing trim edge31along front edges185. Thus, the portion of trim edge31which was conveyed outwardly beyond teeth183of anvil179are sheared and fall away as separate cut pieces37B (FIGS. 15 and 16). As shown inFIGS. 12-16, similar to piece37A, shearing away piece37B forms the leading edge of the next piece37B in succession. Likewise, when blades173shear trim edges31into pieces37A, the side edges of pieces37B are formed. Pieces37B consequently require only a single cut between front edges185and cutting edges177to separate pieces37A from trim edge31. This cut is provided by the subsequent blade plate171as it rotates on rotor165A and trim edge31is simultaneously conveyed out beyond teeth183of anvil179.

As trim edges31enter trim processing machine1in the direction of Arrow F (FIG. 11), trim edges31are cut along an axis parallel to Arrow F by cutting edges176(FIGS. 12 and 15), and an axis perpendicular to Arrow F by cutting edges175and177(FIGS. 12 and 15). Therefore, trim edges31are cut both lengthwise and widthwise and generally perpendicularly in one pass of blade plates171to achieve uniform cut pieces37.

Rotor165A is rotated at a speed such that when trim edge31is conveyed over anvil179at the line speed, one of the plurality of blade plates171rotates through anvil179at precisely the moment to cut trim edge31into the desired uniform size pieces37. As the line speed increases, the rotational speed of rotor165A increases to continue processing trim edges31into the desired uniform size pieces37. Likewise, as the line speed decreases, the rotational of rotor165A decreases to continue processing trim edges31into the desired uniform size. The uniform size of pieces37is considerably smaller in length and width than the original length and width of trim edges31.

A user may configure the specific size of uniform pieces37by replacing anvils179and blade plates171. This is achieved by removing access panels163and unsecuring blade plates171from blade holders169. Similarly, anvils179may be unsecured from anvil mount146and replaced. Thus, blade plates171may include differently sized recesses174and blades173, corresponding to anvils179having complementarily sized recesses181and teeth183.

As shown inFIG. 11, trim edges31are processed into uniform pieces37and are expelled in the direction of Arrow K within channel158. Pieces37exit channel158through duct39and are collected by any means desired by the user. Typically a structure such as hopper41is used to collect and store pieces37. Air conveying technology is commonly used in the art to convey trim pieces31into trim processing machines1. The preferred embodiment of the present invention incorporates air conveying technology into the expelling of pieces37into a hopper41by directing the flow of air through roller housing61, continuing through rotor housing133, and continuing out channel158and duct39.

In operation, raw corrugated sheet21is formed in corrugator3as discussed above where it is fed into edge cutter29at a particular line speed. The line speed changes depending on the particular job requirements and flute size. Sensor26is positioned to read the speed with which raw corrugated sheet21exits corrugator3, and continuously relays this information to trim processing machine1via conductor28. As shown inFIG. 2, conductor28provides the line speed information to motor81which synchronizes the rotational speed of bumpers97and111in feeder sub-assembly49A with the current line speed. Conductor28further provides the line speed information to motor123which synchronizes the rotational speed of shaft131in cutter assembly45with the current line speed. Trim processing machine1must process trim edges31at the current line speed to prevent jamming or ripping of trim edges31.

As shown inFIG. 11, trim edges31enter roller housing61in the direction of Arrow F. Within roller housing61, bumpers97and111rotate to convey trim edges31at the line speed into cutter assembly45. As trim edges31enter cutter assembly45, the leading portion of trim edges31are conveyed over anvils179, and particularly over recesses181and teeth183of anvils179. At the moment when precisely the sufficient length of trim edge31is conveyed over recesses181and teeth183, a blade assembly168on rotor165A rotates past anvil179. As blade assembly168is passing anvil179, blades173on blade plate171pass through recesses181of anvil179. Likewise, at the same moment, teeth183of anvil179pass through recesses174of blade plate171. The passing of blade plate171through complementarily shaped anvil179with trim edge31positioned therebetween, results in a shearing of trim edge31into pieces37A and37B.

As pieces37A and37B fall away, bumpers97and111continue to convey trim edges31into cutter assembly45at the line speed. The required length of trim edge31is continuously conveyed over anvil179in time for the subsequent blade assembly168rotate past anvil179. If the line speed increases, sensor26relays this change to motors81and123, which react accordingly to maintain cutting synchronization with the line speed. Thus, the process of shearing trim edge31into pieces37A and37B is continuous and precise to generate uniform pieces37of trim through dynamic changes in the line speed. Cut pieces37fall downward away from anvil179and travel out of cutter assembly45through channel158in the direction of Arrow K into duct39. Duct39directs pieces37into hopper41where they are collected and bundled for future use.

It is commercially desirable to guarantee a particular size and shape of corrugated pieces expelled from trim processing machine1. As trim edges31are processed into a guaranteed uniform size and shape in trim processing machine1, independent of the line speed, pieces37may readily be bundled and sold as a new product. This represents an improvement in the art, as a new commercial product is created from what was considered previously by the industry to be a waste by-product of the corrugation process. The uniform size may be altered by replacing anvil179and blade plate171, which allows the user to custom tailor the piece sizes for a particular industry or buyer. For example, uniform pieces of corrugated material having a specific size are especially desirable in the equine industry because these uniform pieces37cannot become embedded into the animal's hoofs. Furthermore, the low weight pieces37are easily shoveled out of the animal stall after use. However, it will be readily understood that the novelty of the present invention extends generally to all strip material, and is not limited to corrugated material.

It will be readily understood that conductor28could consist of a wireless communication system, whereby the line speed information is provided to motor81and motor123wirelessly, or by any other common communication system. Likewise, it will be readily understood that trim edges31may be fed directly into a cutter assembly during the corrugation process. However, the preferred embodiment includes a feeder assembly.