WO2015035335A1

WO2015035335A1 - Expandable slit sheet packaging material that interlocks when layered and expanded

Info

Publication number: WO2015035335A1
Application number: PCT/US2014/054615
Authority: WO
Inventors: David Goodrich
Original assignee: David Goodrich
Priority date: 2013-09-06
Filing date: 2014-09-08
Publication date: 2015-03-12
Also published as: EP3041756A1; EP3683166A1; EP3041756A4; EP3041756B1

Abstract

In accordance with a broad embodiment of the invention, a novel paper product is comprised of two or more slit sheet packing material layers, each layer having its own slit pattern design to create interlocking layers of expansion sheet packaging materials. Each layer expands to create a three dimensional open netting of cells of hexagons, and the like, and is designed to have limited nesting with its opposing layer, thereby maximizing the thickness of the combined layers as compared to nested layers. Adjacent layers have differing slit patterns and can be expanded through expander type machinery such that the expansion rates of the differing slit pattern layers can be varied to deliver the same width of exiting expanded material from each layer. Preferably the differing slit patterns produce when expanded, inclined land area that have the same number of rows per inch, but different angles of inclination of the land areas, such that adjacent layers can interlock, that is, have a restricted amount of nesting.

Description

Expandable Sl t Sheet Packaging Material Thai interlocks When Layered and Expanded

BACKGROUND OF THE INVENTION

This application claims he benefit of ^'the filing date of US Provisional Patent Application 61/874873, filed Sept 06, 2013 tor "Interlocking Expandable and Expanded Slit Sheet Packaging Meteriar, the disclosure of which is incorporated herein by reference, as though recited in toil

P1j Field of the I ven Qft

002] T is invention relates to a paper packaging material that Is all expanded, and layered around an object or used as a void fill.

[003] , Description of the Prior Art

1004] There are a small number of liKhe-box wrapping products found In the market today used to fill the open area within a box that is unused by the Item being shipped. Wrapping an item to he shipped puts a harrier e ween it and the hex. It also creates a larger cubic area as It sits within an adjacent void-mii product such as Styrofoam; peanuts. The larger cubic area cushions as well as inhibits migration of the item to the sides of tea package.

oi Pleated Paper of US patent 8,871 480 teaches using pleated paper laminated to one or more outer layers of tissue paper as a cushioning product. The pleat height, paper fiber length, and number of pleats per toot, provide a cushioning, product that crushes as force is applied. This application teaches the use of pleated paper as a wrapping material.

iOOOj Bubbie Wrap®, well known In the art. can be obtained with T to tall hubbies for the use as a wrap and void ill, it Is capable of very good cesh!on;og if made from a copolymer that is not recyclable or Is very difficult to recycle. Homeowners are not able to recycle this type of plastic easily..

|007] US Patent umbers 5,867.871 and §_;688_:δ?0. teach the use et a plurality of individual slits forming parallel spaced rows forming a hexagonal expanded sheet with and without a separator sliest, if requires machinery to stretch the paper Info its three dimensional shape at the customer's location such as disclosed In US Patent 0,538,778 which teaches the method and apparatus for producing the expansion of the slit sheet malaria! performed at the packing site's iocation . This malarial is effective when used In conjunction with the separator sheet but, the separator sheet does not add to the thickness of the material Additions! background information Is disclosed in US Patent 5,782,735 relating to slit sheet packaging materials.

SUMMARY OF THE i¾i¥EiWIQS¾

(0081 A main object oi the present Invention Is to overcome the shortcomings of the prior art.

10091 lo accordance oh a breed embodiment of the invention, a novel paper product is comprised of two or more silt sheet packing material layers, each layer having Its own s pattern design to create interlocking layers of expansion sheet packaging materials. Each layer expands to create a three dimensional open netting of eolis of hexagons, and the like, and is designed to have limited nesting with Its opposing layer, thereby maximizing the thickness of the combined layers as compared to nested layers,

IP10] in accordance with a broad embodiment of the ioveriori adjacent layers have differing slit patterns and can be expanded through expander type machinery such that the expansion rates of the differing si pattern layers can be varied io deliver the same width of exiting expanded material from each layer. Preferably the differing ski patterns produce when expanded _: Inclined land area that have the same number of rows per inch, bet different angles ol Inclination oi the land areas, such that adjacent layers can interlock, that t have a restricted amount of easting. Nesting to an extent sufficient to provide interlocking, is in the range from about 10 to 20% and preferably about 9 to 15%.

10111 in accordance with a bread embodiment of the ioveoilom adjacent layers have differing silt patterns and can be expanded through expander type machinery such that the expansion rates of the differing slit gaPem layers can be varied to deliver the same width of exiting expanded material from each layer Preferably the differing slit patterns produce when expanded: Inclined land areas that have about the same number of rows per inch, but different angles of inclination of the land areas, soon that adjacent layers can interlock, that is, have a restricted amount of nesting and where the angle of Inclination of the first layer ;s io the range Pom SCf to 85* and the angle of inclination of the second layer is ;n the range from 130^» to 95^:: . Preferably, the angle of Inclination: of the first iayer Is In the range from 55" to 7S¾nd optimally In the range from 55* to 85*. Preferably, the angle of inclination of the second layer ;s in the range fmrn 125'^' to and optimally In the range from 12Πο 115", [012] i accordance with another embodiment of the inverta adjacent layers have substantially the same silt aatterrss thai: produce sheets which when expanded the first: layer has lands that are al an angle in the range from 60% 8S^* end the angle of Inclination at the second layer Is in the range from 130^* to 9S'\ Preferably, the angle of inclination of the first layer is In the range torn 55° to 7S"and optimally In tbe range from 55^s to 65^:: Preferably, the angle of Inclination of the second layer Is In tbe range from i 25^* to 105^Kand optimally In the range from 125"^' lo 115^*. If should be noted that tbe angle of inclination of the second layer is a mirror Image ol the angle of Inclination of the first layer; thus, it the first layer has an angle ol inclination of SO \ the second layer has an angle of Inclination of 120^', In this embodiment_:, tbe sum of fhe angles of Inclination of the first and second sheet is 180^*.

[C 131 In accordance with a farther embodiment of fhe invention, the sills are cut to form a straight line col. at one edge of tbe silt and an angled cot along the ether edge of the silt, thus producing a wedge effect out The wedge effect Is sufficient to produce a slit pattern that upon expansion consistently forms a uniform angle of inclination along the entire length of the silt paper.

t014j in accordance with another embodiment of the Invention: sheets of paper or plastic are silt In a

pattern, that open expansion, form an expanded slit sheet as described US Patent 5,538 J78_tfsee for example. Figures 1 and 2). and US Patent 5J82J3S (see for example, Figures 19 and 20), the silt sheets are formed Info rolls, A first roll is unrolled clockwise and expanded and a second roll is unro!ied counterclockwise and exceeded. Preferably, the two rolls are expended simultaneously In an expander device which produces t o adjacent layers of Interlocking expanded sheets having ceils, wherein the cells have land areas that are Inclined relative to anexpanded sheets, and wherein the angle of inclination of one of the adjacent expanded sheets is the mirror image of the angle of inclination of the other expanded sheet. The expanded. Interlocking sheets am wrapped around an object, to form at least four layers of expanded sheet materia: , that ls_; two windings of the double layers of expanded sheet material:

[0151 In accordance with another embodiment of the Invention, one or more layers of si sheet material can he made from a paper comprising a soft paper such as paper towel type material so that it Is soft on the bands while manually manipulating the packaging material around items being packaged. Preferably, one layer is of Kraft paper, and the adjacent layer is of a paper towel material.

[016] In accordance with another aspect of the Invention, expanded slit sheets are layered such that

adjacent sheets uniformly: reliably, and consistently have lands with angles of Inclination that are substantially reversed from each other, and Interlock over substantially the entire length of the sheets and preferably.: over the entire length of fhe sheets, thereby producing an improved packing material as compared to prior art products. Preferably the angles of Inclination one of fhe adjacent sheets Is the mirror mage of the an les of inclination of the lands of the other at the adjacent shee s.

[0173 & a¾mmI¾

(018) The invention will be described with the accompanying drawlngs_: In which;

Ι019Ι FiG.I Is a top vie of one of the layers af unaxpancted silt sheet paper material,

i0201 FI , 2 is a side view of t o identical expanded slit sheaf paper materials as they rest on top af one another.

10211 F!G.3 Is s side view of two Identical expanded sill sheet paper materials with a separator sheet between the layers as thev feat one on fop of the other.

10221 F!G.4 is a side view of two differing expanded slit sheet paper materials placed one on top of the other.

10231 FIG.5 Is a side view of the e nder rolls section within the Infernal workings of the Automatic

Expander.

|024] F!G.6 Is a top view af the expander roils within the infernal warnings of the automatic expands?. 10251 FIG,? is a side view of the Pelt used to rotate the expander rolls.

(026] FIG.S Is a top perspective view af one layer of expanded sheet material,

1027] FI , 9 Is the side perspective view of an example of one of trie gear pulleys used to rotate the

expander rolls,

10281 FIG, 10 is 3 schematic lustration showing a backward orientation of the lead walls of the web.

|029] FIG. 111s a schematic Illustration showing a forward orientation of the lead walls of tie web.

|0301 FIG. 12 Is a schematic Illustration showing the comhlnafion oi a backward orientation oi the lead walls oi an u er web, a forward orientation of the lead walls af an upper middle web, and a backward orientation of the lead walls of a lower middle web and a forward orientation of the lead walls of a lowermost web.

1031 ] FIG, 1 Is a photographic representation of the combination of a forward and rea? a?d oriented Saver of expanded slit sheet material.

1032] FIG, 1 Is a schematic representation of the rollers for feeding unex anded slit sheet materia! to an expander,

1033] FIG, IS is a schematic illustrates of slitting blades having varying included angles,

(0341 FIG. 16 Is a schematic Illustrates of slitting blades having varying cutting angles. (0351 FIG. 17 is a schematic illustrates of offset slitting blades having varying catting angles,

(0361 FIG, 18 Is a schematic Illustrates of offset slitting blades having varying catting angles, [0371 FiG. 19 is a oross-seotionat ie of s ^; shewing a wedge effect cut,

|036| FIG. ISA Is a fop view of the structure of FIG. 19,

10391 FIG 20 is a cross-sectional view of silt shoving a greater wedge effect cut f ran illustrated in FIGS, 19 and 19Ά.

I040I FIG, 21 Is a oross-seetlonai view of slit showing a greater wedge effect out liaa illustrated in FIG. 20,

Description of t e embodl ment of the invention Definitions

[0421 Where the definition of terms departs from the compsonty used meaning of the term, applicant intends to utilize the definitions provided below _: unless specifically indicated otherwise.

[043] For the purposes of the present invention, the term *$i sheet material" refers to the use of offset rows of slits that form a hexagonal or the like, three dimensional paper material that is flexible and can form to the shape of an item needing wrapping.

[0441 For the purposes of the present Invention:.: the term ^'¾eii^' means the hollow three dimensional shape thai is created when ihe s sheet material Is expanded longitudinally.

[0451 For the purposes cf the present invention, the term: lead wall" means the part of the cell that Is the full he¾lii cf the hexagonal shape created from the expansion of the slit sheer material.

[0461 For he purposes of the present invention, fie term "angle oi i0dlne1lon^N means the angle that Ihe land areas of cells form with respect to the plane of the unexpended slit sheet _: erein the coils have land areas that ere Inclined relative to unexpandec sheets _; and wherein the angle of Indication of one of the adjacent expanded sheets is the mirror Image of th angle of Inclination of the other expanded sheet.

[004?) For the purposes of the present Inve tion; the term ^soouneeiing wall^* means the pad of the cell that Is half the height of the cell created from the expansion of the slit sheet material.

[0481 For the purposes of the present Invention, the term "cell s¾e^i: means the open space dimension created when expanding the silt sheet material ,

1049] For the purposes of the present Invention, the term "slit row spacing" means the distance between the rows of slit and nn-slit patterns within the silt sheet material.

050] For the purposes of Ihe present invention, the term: ^'Kraft paper* moans the industry name of neper that Is measured in weight for every three thousand square feet of material. Thus the weight of 50# Kraft

Paper would be the weight of 3000 square feet of paper,

pi 1 For the purposes of the present invention, the lean "basis weight" means the specification relating to paper that measures the weigh! of a certain square toot area ot paper. Thus the basis weight of 3D00 square feet of Kraft Paper weighing 50 pounds equals a SG# basis weight. The basi eight, of Tissue paper Is based on 2,880 square feat.

(0S2j for the purposes of the present Invention, the term "recycled paper" moans material that is

substantia!!;/ made from recycled paper in the 30% range or more and Is paper that has been :retprnort to the manufacturing process, having once or mora been made Into a paper product, and remade into a paper sheet..

[OSS] For the purposes of the present Invention, to term "paper fibers" are the individual component oi paper that makes up 8 paper sheet

(0641 For the purposes of the present Invention, the term testing" means the grouping of ceils onto or Into one other such that an upper slit sheet materia! eel! can fit within the lower silt sheet materia! cell to the point at which the thickness gain i not substantial

[055] For the purposes of the present Invention., the term nterlocking* means toe grouping or cells onto or info one another is such thai, so upper silt sheet materia! ceil can nest within the lower slit sheet materia! cell only to the point at which the average thickness gain of two layers is no less than 70% of the thickness of both layers of a two layer pair and preferably, no less than 80% of the thickness of both layers of a two layer pair. For example, if each layer Is 0.5 inc es thick, then the average thickness would be no less than 0,7 !nohes and preferably no les than 0.8 Inches.

61 For the purposes of the present invention, the term "adjacent" means that two layers are immediately adjoining, that Is. one layer overlays the other without: intervening space and are touching. Layers that nest of interlock to any degree and having no intervening layers, are accordingly, In contact with each o!her and thereldns nejecem.

1057] The term "pattern of cells of expanded sheets" means the ceil shape configurations such as hexagonal or oval, and ceil dimensions such as leg length or width. The term ¾atfem^s means physical

characteristics and dimensions and Is not Inclusive of decorative or ornamental features of the design of a pattern.

10581 For the purposes of the present Invention, the term: "average thickness^* is employed to Indicate that since some nesting may be present In layers of sheet los are within the definition of ^"Interlocking" as employed here, the thickness of two adjacent layers can vary Average thickness Is measured as the sum of the thicknesses measured at a plurality of linear intervals, divided by the number of Inte vals in the plurality of linear intervals. Thus, if thickness measurements are taken every Inch ever a length of two feet, then the sum of the measurements divided by 24 equals the average thickness. [050] For the purposes of the present in ention, the lerm Interlocking adjacent ia e s" means that layers are nested to an ex en thai the contact between adjac nt iavers is sufficient to resist contraction of ex anded sheets, When fee ia ers are interlocked: the con rac ion horn expanded to unex e ded dee to tire paper's memory.: is restricted decease one layer ts casing w a. test di ection and the second layer is pakwg in the opposite direction. Tne degree of nesting depends open tire rigidity of the pacer of each of tire two iavers,: and preferaniy provides at: teas! a 10% ovsslap (n sting) of t e layers scan that toe thickness of the two iavers is no me e t an 00% of the sum of the thickness of each layer,

(0601 For the purposes of the present invention, the phrase "paper wid th after expansion* means the width oi the sheet of paper after expansion of the siif paper sheet The decrease of the width of the sheet of paper after expansion is referred to as decking downO The ^Λ as ream of necking down is the percent decrease in paper width after expansion. Thm a 25 inch width sheet which necks down to 20 inches would he necked down 20%.

[0611 For the purposes of the present invention_: the phrase "paper width diiferenfiai" means the difference in width of two adjacent layers of skp paper sheets. Since different silt patterns will yieid different amounts of necking dowri the paper idt differential peer to the expansion step must he sufficient to yieid tittle or no paper width differential after the expansion step, it should be understood that the sheets et expanded paper can Pe trimmed down to negate any paper width differential post expansion. However; this would constitute a waste of paper and require an additional step or steps, and accordingly: it: is preferable to negate any paper width differential by determining a pra-espanaion paper width dtffe?enliai that act sieves, in combination with the ski patterns of each of two adiacenf sheets, a substantially ioentieai paper widths post expansion.

p2j For the purposes oi the present invention, the term "Operator" means the person that operates the machiner that automatically expands the slit sheet material: that dispenses the product towards the operator.

(0631 for the purposes of the present invention, the term "switch baef means the reverse: of the angle of inclination of the land at seme point or points along the length of a sheet of expanded slit sheet material A reversal of the angle of inclination from * to - 80* (80* to 120*) constitutes a switch back,

(0641 For the purposes of the present invention, the term "wedge effect" means the ending of a slit to form a skt having a straight line cut along one edge and en angled cut along the other edge of the slit,

(06S1 For the purposes of the present invention: the term "soft paper means the particular grade of paper used for absorbing purposes, such as tissues.: drying oloths, paper toweling, napkins and handkerchiefs. While these paper products, unlike their woven fabric counterparts, are typically intended for disposable use, in the present invention soft paper is employed for its soft ieei, smooth structure, and good strength in both dry and wet states.

Sit Sheet materials

ίθββ] For the purposes of the present Invention the descriptions of the paper and silt patterns within the embodiment of US Patent: 5,66? _:8?1 can be used ithin tills application. The material can be as described in he ^s871 patent, except: that the two differently sized sir! patterns are employed la the resent invention, rather than just the one pattern of the ¾?1 patent These two slit patterns substantially negate the nesting pro lem associated with the prior art patent US Patent §,687,8?!

[067] Further information relating to the paper which can be used in the present Invention_: slit patterns, and the expansion process is found In US Patents 5,538,778, S,667_:8?! 5,688,878. and 5.782 J35,fiie disclosures of which are Incorporated by reference herein, as though recited In full

S^; Each slit pattern will require varying paper strength and thickness to perfect its cr s strength and ease of stretching within the automated expander,

(069) The slit pattern dimensions sat forth below are one example of the composite products from the two or more varying silt sheet materials. There are a number of si sheet variations that will work to Inhibit nesting and the specific dimensions and shapes created below should not limit the patterns that can be used te make the new art. The critical feature is that the silt patterns of adjacent layers differ in s length, spacing between sis In a row, and/or the spacing between rows of slits.

[070] The paper used to manufacture the slit sheet material is preferred te be recycled and is in the range of 30-8 pounds in basis weight dependent upon the ceil size of the si sheet expanded material. Virgin paper has longer libers and will produce a firmer product with equivalent basis weight as recycled paper. Again, depending on the cushioning required one may use a 30 pound recycled paper to obtain a very soft cushion and alternating between recycled and vi gin as the paper weight goes up fine tunes the cushioning effect. Additionally, a soft cushion recycled paper can be used for one sheet of the pair of sheets and the other can be a higher weight recycled paper or virgin paper. Kraft paper Is manufactured according to the Tappi Ϊ- 10 (standard of 3,000 Square feet of material per basis weight, As an example a Kraft paper with a basis weight of 40 moans that 3,000 square feet will weigh 40 pounds, interestingly the paper is about ,004 Inches thick but this can vary based on crushing methods to produce different surfaces,

fp?1j In the case of a cushioning product made from Kraft paper the Ideal paper weight, depending on the cushioning requirements Is 30 to 00 pounds. !Q72i It is preferred to use the si. pattern that Is approximately fhnee-fo-one In si e between llie length of the si: portion and the un-sl!t portion of the slit shoe! materia!, in ibis instance a VT slit portion followed by a 3/ 6" un^»s portion is a preferred pattern In tie first row, Each row is W apart and bisects o is transverse to Ihe direction of maoufactunng the slit sheet material Each slit pattern row below is offset to ihe above pattern such that the silt portion bisects ihe uns!it pattern of the upper SOW and so forth. This al e nating: pattern enables the paper lo be expanded in lo the web of hexagonal diamond, square, or round shaped three dimensional colls that are created dependent upon the specific slit pattern. A hexagonal pallem Is created with the approximate ihreedo*one sill ID unci lengths. If has been established that the hexagonal shape is the strongest ol a! the cat! shapes and therefore Is the preferred embodiment to ihe new art. There are exceptions when a softer cushioning material Is required where one of the slit: sheet materials is a exagons! layer with the adjoining layer si sheet designed to be a square, n this instance the preferred embodiment is for both layers to substantially create hexagonal cells

|0?3j The second layer of silt sheet material will be of the same three dimensional thickness. The thickness con he oroated from Ihe spacing of the rows, in this instance the spacing is 1/8" thus creating 1/4" long ceils. Because these ceils can only rotate shod: of 90 degrees toward a vertical orientation, the total height is approximately 3/16" overall The lead wall of the cell is the portion ol the coil that makes op the full depth ol Ihe sill shoot whan expanded. There are two lead walls created no mailer what shape Ihe cells create o silt pattern used. These two lead wails face Ihe direction (if manufacture and Ihe surface area is made up of the un-s!ii area within Ihe row and the space between the rows times 2, The depth of the lead wall can also he described as the onsi space between every other set of rows or between the first and third rows,

| 741 The overall height of the expanded silt sheet materia! can also be described as a series of rows such that the first row of silts at position *CT Is followed by its offset am si portion of the row underneath el position 1 /8" below and not until the third row appears and the offset again places a silt at position I Tlhereby creating a lota! height of 1/4^* lor the load walls of the hexagonal ceil

[075] The first slit sheet pattern creates a 1/4" lali lead wall with each hexagonal side approximately being 3/ 16" long. The second silt sheet pattern Is also If tail by using the 1 ¾" row spacing. The legs of the cell are approximately 10 to 30% less or more to create an Interlocking composite prcduel, In this case Ihe preferred sue would be A" slit x .15^s nnsi creeling a cell that will he 20% smaller than the first si sheet pattern_:,

10761 The second expanded si sheet pattern creates a cell that easily oouid fit inssde the first expanded slit sheet material but is inhibited by the increase in quantity of the smaller call size causing 1.2 ceils trying to fit within one call of the first expanded sheet which ₍ is Impossible.

Ι077Ϊ in order for the operator to receive both slit sheet expanded materials at the same speed a special expander is required. The first expanded sheet layer expands from T to approximately 2 1/8* inches depending upon paper strength and thickness. In the present invention the 60 pound basis weight paper expands to the 2 1/8^* inches for the 1/2^S x 3/16^K first s sheet layer. This Is an approximately 213% Increase In the length of the silt sheet materi l and the expander will need create this exact expansion property for the first layer.

1078] The second layer will be twenty percent smaller In step and therefore will expand 193% In length.

Therefore the second expansion rollers within the expander machinery will have a reduced expansion ratio to accommodate this smaller amount of expansion. This reduced expansion ratio would therefore automatically reduce the smaller secondary web layer speed exiting from the expander. To maintain the same exiting spaed tor both layers the back rollers that sat the overall exit speed will have to be adjusted to 20% faster for the second layer,

[07Sj Additionally, slight variations in cell size, of 5 to 10%, can be opened with the same Veicro to rubber roller ratio as the larger call size due to the slipping effect of the Velcro rollers. As the ceil ύζ& grows the effect is minimized and either a larger oeil ;s not opened fully for maximum benefit or a small cell shows fears or complete feabog of the slit sheet material,

[0801 With only a slight cell size variation the paper width does not have to be exact such thai ii one web is slightly wider by no more than 6 to 0% then the efficiency of wrapping Is maintained. This ould make the loading of the expander easier as the upper web could be the lower web and visa-versa and the only difference weald be the ceil size on the upper weh mav change from smaller to larger or visa-versa.

1081] Two expanded sill sheets with a tissue separator have a thickness that Is theoretically 3/16^* + 3 16" ^» 6/ 6" ,375^'T but has beep measured to be 11/32" or .344". By way of contrast two !nfedooked layers of expanded sheet material, In accordance with the present Invention measured at 3/16" + 3/16" to produce a thickness of 5/ 16^s or ,3 233 The ioss of thickness of the two interlocked layers of expanded slit paper represents the amount of interlocking of the two aefaoenf, ovenaid sheets of expanded silt paper of the present invention.

10821 While this represents a 9% loss of thickness, it has been found that In use, the expanded silt shaefs with a tissue separator fends to flatten due to the ceils having limited rigidity under a load and has a tendency to retract By way of contrast, the interlocking design of the present Invention, as compared to the tissue separated design of the prior art_: ;s more resistant to deformation nnder load, more resilient, and resis s retraction. It has been found that In use. the design ot the present Invention produces a ra that Is thicker than the tissue separated design of the prior art, presumably because of its ability to retain Irs thickness, in contrast to the tissue separate; configuration. The tissue separated design of the poor art: has been found to generally retain less than 75% of Its expanded length, whereas the crisscross pattern of the present invention tends to retain greater than 75% of Its fully expanded length.

10831 in anofher 2 layers with zero nesting has a thickness of 2.25^s, were each expanded sheet layer has a thickness of 0.1875' (0.1875 X 12 - 2.25". e ample 12 layers have a thickness of about 2^s, re resenting a loss of thickness of about 11%,. Thus, preferably, the nesting is limited to 10 to 20% and most preferably It Is limited to 9 to 15%.

[084] The concept of the expanoor la to continuously feed the slit sheet layers to the ope ator and

simultaneously expand those layers for ease of use. Otherwise the operator would have to manually gull the layers on a repeating basis as more ftat layers of silt sheet material are delivered, To facilitate this two rolls approximately 10* apart from the front to the back ot the machine o erate at different spears, A separate set of ru er coated feed rollers drive the first slit sheet material Into the expander. The second set of expander rollers at the front of the machine are Veicro coated, grab the slits, and drive the slit sheet to its ex ected configuration by operating 213% taster than fhe back rollers. The second sil sheet materia; will feed Into an additional sel. of feed rollers and expander rollers that will set the ratio of 193%. In addition, the back rollers as well as the front reliefs will operate 20% fester idsn the first set of rollers for the first silt sheet material. The design of the drive system shown In FIG $, 7, and 9 are with the use of a timing belt and corresponding gear pulley design This does not preclude the design of typical flat or no- teeth belt designs which provide can slip when ynder load.

[085] Soft Paper

Γ0Β61 The sill sheet material can be made from; a variety of papers including Kraft Papers, recycled and virgin papers and the like. These papers when expanded form sharp edges that are sharp to the operators hands and cause oafs to the skin. In most instances the operators where gloves when using silt sheet expanded paper materials, The new art as described below reduces or eliminates the sharp edges to the paper by ui&ing a different type of paper yet used In the manufacture' of slit sheet paper.

[087] The manufacturing of Soft Paper Is described In prior art US Patent 5,061 ,344 for a ¾efhod of making Soft Paper", For exarnple/^'3 4 describes Soft paper torn cellulose fibers as being manufactured b wet- forming a first fiber layer, Thereafter sir-borne dry fibers are deposited directly on one or both sides of the wehforrned layer while Ibis is si! et_s so that a second and possibly a third fiber layer are formed on the first one. Fiber inding thereby arise bet en the layers. The wei-forrned fiber layer gives the sort paper its strength, while the dry-formed riders give a set! surface. The disclosure of US S_:Q6!344 further describes as another method of forming soft paper, dry-forming, in dry-forming, dry paper-making pulp is fluffed to form fibers which are suspended in air. The ir-tone fibers, without addition of water or other solvent, are deposited on an air pervious wire, and these fibers are bound together by means of a suitable chemical binding agent or agents which are added thereto. Further manufacturing details are described in the "DETAILED DESCRIPTION^* oi the "344 patent. The disclosures of US 5,061.344 are incorporated herein by reference as though recited in full Additional Information regarding soft paper is disclosed, for exam le, in publication US 201 /0130997. the disclosures of which are Incorporated herein by reference as though recited In full,

S; This Is one design for making soft paper and can be utilized fo expanded sheet material as it has good fiber strength and c n be expanded Into lis three dimensional cell form. The use of Ibis paper is within the range of 40 to 90# basis weight it the paper fibers running in the machine direction for good expansion strength. The soft paper thickness is thicker than typical Kraft paper thicknesses, as well known In the art, with soft paper thicknesses varying from .0O8^:< to ,012^' .The preferred basis weight for the soft paper Is about 70, With a thickness of about .0 0".

10891 Fig 1 1s the fop view of one layer of the slit paper prior la expansion with 100 being the width of the silt and 101 being width of the ons dimension. 102 Is the distance between the rows.

10901 FIG 8 is the top view of one layer of the silt sheet expanded to its three dimensional form with 800 being the open ceil area created by the expansion, 801 being the lead wall or land created, and 302 being the connecting leg. if is noted that the terms lead wall and land are used interchangeably to Indicate the region 801.

10911 Fig 2 Is the side view of sift sheet expanded material. In accordance with the prior art. showing the nesting of two identical layers 291 and 202, with reference number 203 showing the virtually complete contact between the two layers.

i092i FiG 3 Is the side view of the use of a separator sheet, in accordance with the prior art, that negates nesting in accordance with the prior art use of a separator sheet 302 between two expanded sheet 301 , The reference number 303 indicates the open space between the separator sheet 302 end an expanded ilent

10931 FIG 4 is a side view of two expanded layers 401 and 402 of the prior art, having regions 493 where side walls of adjacent laye contact each other but nesting Is minimized due to the use of differing si! ealtems tor layers 401 and 40:2, Reference numeral 404 Illustrates the open space between adjacent layers of expanded sheets which has been substantially maximized due re fhe differing slit patterns for layers 401 and 402. It should be understood, that in use, the dimension difference between tbe cells of sheafs 401 and 402 should be greater than llustr t In order to negate nesting to a greater extent than illustrated In FIG 4.

jOS4] FIG 5 is a side schernatlo Illustration of an ex nding operation In accordance with the present

invention. The reference numerals 500 and 502 indicate unsxpsnded slit sheets driven by pinch rubber rollers 503 into the expander rolls section 504 within the inte al workings of fhe automatic ex a der. Reference numerals §08 and 509 indicat slit sheafs 500 end 502 respectively, In their expanded form. The slit paper is feed counterclockwise from a first roll 140:2 and clockwise from a second roll 1 00 to provide for reversed angles of fhe lands in accordance with the present invention.

f085j e pan ion rollers 504 em lo a hook and loop material 601. such as Ve!cro§, which covers the front roller section which pulls the slit paper faster than 503 feeds providing the expansion and exiting of the expanded slit paper, it should be noted thai the liook" layer of the hook and loop material Is used rather than the loop portion of the nook and loop material, Tbe driving process Is recisely driven with motor 608 that turns drive shaft 607 that has attached two identically drive gear pulleys 604 and 805 that engage the teeth of the drive belt 809, Timing belt 009 trims gear pulley 693 that Is precisely sized to create the 213% ratio to drive pulley 606 attached to timing bell 000,

[096] FIG 7 is a schematic side view of the tiering halt: 600 and Its corres onding teeth 701 that interact with the gear pulleys In FIG 6 drive gears 603, 604, 505, and 606 that are precisely s& to create fhe varying speeds that provide fhe expansion and exit speeds, FIG.? shows bet 609 used to rotate the expander rolls 60 and fhe feed drive roils 503. Timing belt 609 turns 504 faster than 503 due to diameter difference for the guides for the two rollers . FIG.S Is the side perspective view of gear pulley §00 that corresponds in varying sizes to gear pulleys 603, 604 _: 60S_; and 006 in FIG.6 The teeth 901 create the open areas 902 that create the space for the timing bell In 609 FIG,? to mesh continuously creating a perfectly timed ratio as tbe expande system Is turned. Gear teeth 701 of FIG.? fit within the open spaces between teeth 901 and create the precise drive speeds required

10871 In one embodiment one layer can he the soft paper, and the other Kraft, if the slit pattern of the soft and Kraft are the same.: the cells would nevertheless tend to be different because of the characteristic differences between soft paper and Kraft, In any event, tbe use of cell designs that produce mirror image land region are preferred. The term minor Image, as employed herein, refers to a oell design which produces a desired angle of inclination and ay feeding eeuntemtocR ise f o a first roil 1400 and clockwise f om a second roll 1 02, to produce reversed angles of inclinations of the Iwo expanded sheets form the expander. Thus, if the angle of inclination of a first slieel is 60*, then the reverse fed second sheet will nave an angle of inclination of 120 degrees, and is Identical in form to the first sheet but with the structure reversed, as by a mirror,

{0981 If has no been found that two adjacent ceil orientations are directl affected by the wedge effect from the cuffing tool. The sham edge of the tool Is where the knife is at Its thinnest. In the case of the hard anvil die cutting system the knife edge penetrates the paper to almost f le deepest layer of fibers but never touches the anvil. The yn-penetrated paper section of paper Is then crushed and obliterated into paper dust This enables a complete cat while dramatically extending the life of the cutting die. The knife is made lo have a sharp edge and bevels outward from the edge so that it is sturdy. This bevel creates a wedge sheet on the paper. Viewing the paper from the side on which the knife first penetrates the paper, Ihe sill, entrance side", one can see a wider cm verses the underside which has a much finer looking cut The wedge effect creates this difference and this difference orients the ceils to angle reversely from the direction of manufacturing. If one were to lock at the ex a ded silt sheet at the exit of the cutting die {after cutting Is achieved) the ceil onentatlon would inhibit one from look t o gh the expanded sill sheet as It Is angled hack towards the machine,

|099j Utilizing the wedge effect so that the cell onentatlon Is backward combined with roil of si paper where the {fie cutting comes from underneath the paper, thereby cre g art angled forward sill pattern, the cross interlocking effect can created continuously.

10100] Prefembly, a single slitting device is used to silt a plurality of mils of ex anda le paper. Two or mom layers of slit sheets are fad to an expander, with the roils being simultaneously fed alternately clockwise and oauntemtoekwlse,

[0101] The use of cell designs that produce mirror image land regions are preferred. The term mirror Image, as employed herein, refers ¾ a ceil design which produces a desired angle of inclination and by feeding counterclockwise from a first roll 1400 and clockwise from a second roll 1402, reversed angles of Inclinations of the two expanded sheets are produced by the expander. Thus, if the angle of Inclination of a first sheet is 60 , then the revamp fed second sheet will have an angle of inclination of 120 degrees, and ;is Identical in form to the first sheet, but with the structure reversed, as in a mirror.

[0102) In another embodiment the slit pattern can be the same for both Kraft layers bet the speed of the rolls, and consequently the extent to which the layer expand, would be different, and thus would lessen the amount of nesting, it should be noted thai the tendency of the two levers to "relax" can cause the cell structures to be the same even though the expansion was different. T us, the use of different silt patterns s preferred in order to optimise th bili to negate nesting.

(0103] it is important to note that the maximum stretch provides the best cushioning. The product works while under tension, it is easier to maintain that tension wit? the system of the present Invention than with the system of US Patents 5,538,778 and 5782,753 because the interlocking of layers serves to maintain the silt: sheet under tension,

[0104] Pre-expanded material termed In accordance with the system of US Patents 5,538.778 and S.782 53 Is not as stretched as much as It should, be. There Is a limitation to the stretching, due to the tissue and slit pager helng on Ihe same roll and therefore cannot he independently teosloned. Therefore Ihe tissue gets taut and the slit sheet gaper does not. The new art eliminates the use of the tissue paper separator sheet. In ot the expander process or the pre-exganded process, a hotter ex a sion can be obtained due to the absence of Interference from the tissue separator sheet.

[0105] The cell opening effect orients the lead wall to be either angled forward In the machine direction or angled backward from the machine direction. Angled forward orients the cells such that If one were to look downward at the cells In front of the expanding wed., as the operator would, one would be able tc see through: the slit sheet material. If the angle is backward then the operator would see the rows of iead wails such that i Is not possible to see through the expanded sheet material.

10106] Attention Is Invited le Ftg.9 of US Patent 8,899,578 winch illustrates the angled orientation of the cells ef the expanded silt paper and the nesting that occurs when one sheet: is laid over another layer of expanded sill paper having substantially the same angled orientation,

10107] it has no been found that orienting the rolls of unexpended slit sheet material onto the rollers of the expander such that the exit surface of a first silt pager sheet faces the exit surface of the other sheet, or the slit entrance surface of a first slit pager heet face the slit entrance sudaoe of the other sheet, upon expansion, creates a crisscross pattern of expanded sheets. This crisscross pattern creates a more resilient and firmer material then two sheets oriented In the same direction The crisscross expanded sheets can nest to some degree, up to approximately 50% but due to the increase In resiliency the product become actually stronger and not able to nest further. Lighter weight paper can be used to maintain the same resiliency as non-crisscross product as well as reducing costs in paper and tooling. The degree of nesting is directly related to the angle of inclination of the lands schematically represented In Figs 0-12, Looking now at FIG 10 the lead walls/lands 1001 are oriented backward to the manufacturing direction 1006 which is also the direction the expanded sheets exit the expander. This causes the eye of an operator 1005 facing the web to he inhi ted from seeing through the expanded sheet M see the surface areas of the lead walls 1001

10108) tooksog now af FIG 11 the lead walls 1003 are oriented forward in the manufacturing direction 1 06 which Is also the direction the expanded sheets exit the expander. This c uses the eye of an operator

1005 facing the eb to he able to see through the expanded sheet layer.

i0 9| FIG 12 combines the forward and backward layers of FIG 10 and FIG 11 to create a crisscros pattern with the lead walls In the backward direction Interacting and bisecting lead walls 1003 leaving open spaces 1 02 and 1004.

10110] As shown In FIG. 12,a f;rsf layer having lead wails 1001 are oriented backward to the manufacturing direction lOObhthat Is. the direction in which the paper travels during the sitting operation. With res ect to the plane of the silt paper the lead walls 1001 are oriented backward thus forming an angle of less than 90% the plane of

the paper while the forward oriented lead walls form an angle of greater than Sir to the plane of the paper.

[0111] The arc represented by reference number 1206 thus must be much greater than 0^:5and much less than 180", and can range from 135 to S degrees, and preferable from SO to 30 degrees, and most preferably Is In the range from 60 to 30 degrees, it should he understand thai the are can vary slightly across regions ef tee paper bu the angle of an Inclined land must not reverse or ^'switch back" to the reversed angle of inclination. It should also be understood that the efoser the angle of the lead walls/lands to the vertical the thicker the composite structure,

10112] The arc represented by reference numeral 1010 can range from 50* to 85* and the angle of inclination 1012 of the second layer is In the range from 130* to 95Mfie angles of the lands 1001 and 1003 are relative to the plane 1008 of the unexpended sheet material. Preferably, the angle of Inclination of the first layer is In the range torn So to 7o*and optimally In the range from 5o^¾ to 65^" . Preferably, the angle of Inclination of the second layer Is In the range from 1 5* to 105*and optimally In the range from 1 5 ^" to 1151 The angles of inclination of the two adjacent expanded sheets can be different, provided that they are In ranges previously noted, and provided the silt patterns, though different produce at feast about the same or the same number of lands per Inch such that the adjacent lands Interlock as shown in Fig 2. Thus, angles of inclination 10 0 and 1012 can be (liferent, provided the celt dimensions produce consistent Interlocking as illustrated In Fig 12, The space 102, as illustrated In Fig 1 , can be varied to produce varying angles of inclination,

10113) In another embodiment of the invention, adjacent layers have substantially the same silt patterns that produce sheets which when expanded the first layer has lands that are at an angle In the range from 50 to 05^s and the angle of cli ation ef the second layer Is In the range from 130* to W, Preferably, the angle of Inclination of the first layer is in the range from Sf to 75^" and optimally in the range from 55 lo 657 Preferably, the angle of I dication of the second layer Is In the range irorn 125^* to 105"and optimally in toe range from 125^* to 1167 It should bo noted that toe angle of Inclination of the second layer Is a mirror image ef the angle of Inclination of the first layer, thus, If the first iayer has an angle of inclination of 607 the second layer has an angle of Inclination of 120^"*. in this embodiment, the sum of the angles of Inclination of the first and second sheet is 180

10 1 ] FIG, 13 shews that the reverse orientation ef the adjacent layers of expanded sheet materia! serves to reduce nesting. It has been tonne that the low level oi nesting which Is exhibited by the mirror Image adjacent layers serves to reinforce the composite structure due to an Interlocking effect. Nevertheless the result Is a thicker composite structure then Is obtained from a composite structure In which Is not cross-expanded. The term ¾ross-e: pauded^N as spoiled to a composite expanded slit sheet materia! means a structure in which there Is a combination of a backward orientation of the lead walls of a first expanded slit sheet or web and a forward orientation of the lead walls of an adjacent web, as shown in FIG, 13,

101 5] The call dimensions are selectee to provide the minimum amount of overlap of layers, that is_s

minimum nesting, in order to get the maximum product height. However, there must be overlap of layers to get sufficient Interlocking, The amount of overlap depends on the angle of the lands that are

Interlocking, The Interlocking of the reversed angle layers serves to Inhibit refraction of expanded sheets and provides optimum product resiliency ,

10 161 Looking al the system from anothe angle, you want 100% retained expansion but that is not feasible.

The Interlocking system of the present Invention can provide at least ?S% retention oi expanded length as compared te less than 78% retention: of expanded length using the system of US Patent 5 660.678. The ccntre!leu/llm!fed Interlocking of layers changes the properties of the wrap compared to the tsrleaf design because it resists flattening ef the layer when under load. In the Interleaf design, the two peripheral nest regions merely nest without resisting flattening of the layers under load. The present invention produces a product having greater resiliency and loud hearing capacity as compared to an interleaf design,

10117] As illustrated In FIG, 14. the feed roller 1400 is seen to rotate counter to teed roils? 1402 thus oneniing the roils of une ^od^ silt sheet materia! onto the rollers of toe expander such that the exit surface ef a first silt paper sheet faces the exit surface of tie other sheet , or the slit entrance surface of a first slit paper sheet face the slit entrance surface of the other sheet, upon expansion, creates a crisscross pattern ef expanded sheets. The expansion process with the Expander of FIG 14 Is illustrated io FIG 5. (0118] Both the $» sheets of US Patent 5_:782,?3S and those of the present imn$m_f cannot line up perfect to got maximum height. No flexible si sheet product could align lags on each other that are at §0o with respect to tie plane of the noexpanded silt sheet material. Thus, the maximum thickness of a layer of expanded sheet material Is less than the heigh! of land areas that are at 90

[01191 The lands 2020 and 2032 of Figure 20 of 735 want o nest because there is a perfectly sized call of the upper sheet wanting to perfectly fit Into the lower cell especially when under tension. The tension shapes the hexagon and angles I perfectly with respect to the angles of the adjacent layer as Illustrated in Figure 2 of 735.(0120] The product of the present invention employs opposing angles for adjacent layers of expanded sheets and thereby uses the tension to ma imiz height. As an operator stretches the lower leg of the upper expanded sheet: finds its rest, towards the top of the lower sheet. With a loss of tension the leg will skip downward Out can never fully nest.

10121] By way of contrast with the present, invention, the slit sheets of 735 nest completely, or near

completel _: as elagramrnatloally illustrated In Figure 9 of the 735 patent and thus there Is a need for interleaf of US 5,888:578, as Illustrated in Figu e 8 of m

[01221 h ^;i essential that the cells open upon expansion to form lands lliaf consistently, uniformly, and reliably align in the same direction as Illustrated in Figs, 10 and 11 It has been found that during the expansion process_: the angle of inclination of the lands periodically reverse such that at some unpredictable position along the length of the expanded paper, the angle of Inclination of the land "switch oackT from a forward to a rearward inclination and vice versa. The switch back effect causes some regions of a sheet of expanded pape to he Inclined as Illustrated in Fig, 10, and then reverse to an inclination as illustrated in Fig 11. The switch back does not occur simultaneously for both sheets of expanded a e and thus there can be regions in which the angle of inclination is the same for both sheets and the ceils of the sheets nest In each other,

10123] it has no been found that layers of expanded slit sheets In which adjacent sheets consistently have lands with angles of inclination that are substantially reversed from each ether, interlock ever substantially the entire length of the sheets and p efe abl : over the entire length of Ilia sheets, thereby producing an improved pausing material as compared to prior art products. Preferably the angles of Inclination one of the adjacent sheets is the mirror image of the angles of Inclination of the lands of the other of the adjacent sheets. 0124J It h s now been found that the method and devices for stiffing of fhe paper has a direct relationship to the tendency of the angle of inclination of the lands to reverse during the expansion stop, While it is necessary to produce sttf sheets that expand uniformly and consistently ever substantially the entire length of the sPeets and predaabiy over the entire length of the sheets, it is not narrowl enseal as fa what technique is used la produce sirf sheets that uniformly expand to produce a consistent angle of inclination of the lands, that Is, tree of regions tha switch Pack,

101251 The blade used to silt tie paper Is beveled te produce a sharp edge and the sharpness must be

maintained to arevant fhe switching effect from causing a reversal of the angle of inclination of fhe land ragion of the cells,

10126] The sitting operation can employ blades that press almost through the paper to a hard anvil or blades that cut through the paper to a soft round anvil. The fool and anvil relate at the same speed as the paper sheet thus cutting with high precision making fhe slit sheet material The sharp edge is made with a beveled edge which means Ida! if becomes Increasingly narrower until it is a fine sharp edge from the cylinder to the sharp edge. This creates a wedge effect on the paper that If is cutti g. Even though the paper is only .004 la ,012" the wedge effect Is enough to produce a ceil opening effect. The sudace ef toe sheet materia! thai fhe blade edge Initially contacts, that is, the blade entrance sudace Is called fhe slit entrance or obverse side ot the paper. The surface that the blade exits is called the exit or reverse sudace ef the sheet material

1012?] The adverse effect of switch back can be obviated by the use of a separator sheet as disclosed in US Patent §,08d,6?8, II has now been found that fhe adverse effect of switch back can be obviated through the application oi the wedge effect to the slitting operation. The wedge effect must be sufficient to produce sill paper that upon expansion, continuousl causes fhe land regions of each cell fo uniformly open without switch back,

[0128] The wedge effect increases with Increasing thickness of the paper being silt,

10128] The wedge effecl increases with increasing Included angles of the slitting blades.

[0130] The wedge effect Is optimized when the wedge edect Is limited fa one edge or side of a silt. That is, the net wedge effect Is based on the difference between the wedge effect on the two edges of a slip and optimally, one edge Is free of the wedge effect. The use of a blade that has one cuffing side that forms a OIF angle with respect fo the plane of fhe paper being slit Is preferred fo obtain a sill: in w ich one edge of the silt Is free of fhe wedge effect. Conversely, increasing fhe Included angle between the iwo catting edge surfaces of a blade increases the wedge effect,

10131] The wedge effecl as Illustrated In Figures 10, 19A, 20, and 21, Is shown to be progressively greater from cross -sectorial views Figure 19, io Figure 20, and to Figure 21 la igure 21 tea wedge effect, causes a reglca 2104 of the sili edge 2100 to protrude below the bottom surface 2106 of the silt sheet 2110.. Figure 19A is a fragmen ary fop view of the slit sheaf of Figure 19. showing fha wedge surface 800 and the straight cut edge of the slit 1802,

10132] The greater the angle of the bevel of Hie cuffing blades of ttie slitter rolls, the more consistent the expansion of tie slif paper lo fornr lands with an angle of loc!inafion that Is consistent along tie length of the expanded sheet. A variety of blade designs ara instated In Fig. 16. with the bevel angle of P!ade (1) producing better results than tie designs of blades (21, P¾ (4) and (5). Blade ¾ has the narrowest bevel angle and ould not produce a product that Is free of "switch back* of angles oi inclination of the lands of a sheet of s anded slit paper.

[0103] The blade design 1600 or Fig. 16 has the same angles A and D for both bevels, aed would not

produce a product that Is free of ^: swileh back" of angles of inclination of the lands of a sheet of expanded slit paper. The blade design 1802 has a roughly 45° bevel angle (8) end applies a wedging action against one side ef the slit and a straight cut against tie other edge of a slit due to the 90^s angle (Eh The wedging action of the bevel having an angle (S) forces the surface of the paper downward along tie surface of the paper at the edge of the silt while the noivbeveied side of the blade have an angle (£} or about 90'^' applies no wedging action. The blade design 1604 has a wider bevel angle (C) than the blade 1600, but similar to blade 1602, apples a wedging action against one side ef the slit anil a straight auf: against the other edge of a slit.

|01341 Life of slitting tool blades is based on the number of revolutions of a tool produces switch hacks that are less than 20% of length of a sheet of si paper on a roll or In flat section. At the end oi the life of the siting too!, the blades are sharpened or replaced. When the combined lengths of switch back regions exceed about 20% of the length of the rot, the blades must be replaced or re-sharpened. Optionally, the replacement or re-sharpening of the blades can be set for the combined lengths of switch back regions exceed about 10% of the length ef the roll. Interlocking occurs in regions where two adjacent, expanded sheets are free of switch back or where bom sheets have undergone switch back in the same region. Preferably, at least 80% of two adjacent sheets Is Interlocked and most preferably, at least.00% of two adjacent sheets Is interlocked. Looking at: interlocking from another perspective, preferably no more than 20% of adjacent sheets nest due to switch back and most preferably, no more than 10% of adjacent sheets nest due to switch back. Phrased anofnef way, the minimum desired interlocking occurs when up to 20% of adjacent sheets have undergone switch hack, In regions where both sheets Have undergone switch back, interlocking will occur and thus such regions are excluded from the calculation of the amount of switch back that has occurred.

10135) in ao alternate blade design suitable for use th salt anvils, fie blades 1700, 1702 _: and 1704 are of set as compared to the blades of FIG. 16,1 no design of blade 00 has a bevel angle (F thai can produced a wedging effect, but bevel angle (I) also can produce a slight edg ng effect thus negating the beneficial affect of the bevel angle (F).. The blade design of blade 1702 produces a substantial wedging action dee to the bevel angle (0) and no counteracting wedging torn the straight side of the blade represented by angle (J). The blade design of blade 1 04 produces a substantial wedging action due to the bevel angle (H) and no counteracting wedging from the straight side of the blade which forms and angle greater than goo it the paper that le being silt.

|013δ] Blade 1800 of Fig. 18, Is an Illustration of a blade have an excessive bevel angle ( ) in combination with a substantially 90* angle |U. By way of contrast blade 1802 has different bevels for the ¥ shaped cutting edge of blade 1802 such that a wedging effect Is produce b one side of the V shaped cutting edge and no wedging effect Is produced by the other side of the V shaped cutting edge because of the bevel angle of about 00^s prodeces no wedging effect.

(0137) To produce expansion of the silt paper and form lands with an angle of inclination that Is consistent along the entire length of the expanded sheet, one side of the cubing edge of the blade Is at an angle of substantially less than SO* with respect to the plane of the paper and tie other side of the cutting edge of the blade is at an angle of at least 00^s with respect to fie plane of the paper, and preferabiy at an angle of 0*.

[01381 The wPdginp action of the silt forming blade forces one edge of a silt to be below the plane of the silt sheet, at least at the opposing ends of the slit, thus biasing the colls toward a consistent opening angle during the expansion step

Ϊ0138) The preferred range for the bevel angle Is In the range from 1 * to 3o when measuring the angle

between the two sides of the cubing region of a blade. With respect to the angles (8) and fCl the range Is between 97 and 8a degrees lor the beveled surface and SO degrees for tbe anbeve!ed surface.

10140) Because virgin paper is thinner than recycled paper, recycled paper responds more substantially to the wedging action of the silt cutting blades as described above, thus optimizing the ability of the recycled paper to form a uniform, consistent angle of Inclination of the lands along loo entire length of an expanded slit sheet.

10141) Virgin paper can be thinner than recycled paper and provide equivalent strength based en the longer cellulose fibers. The thinner paper will he less affected than a recycled thicker paper equivalent and thus would need a shallower bevel anglers knife. Looking !o F;g 16, the ngles (8) and fC) would have to bo shallower for Virgi paper than tor eceded paper, from another perspective, the included angle of the bevel should he greater for Virgin paper than for recycled paper, Thus, for Virgin paper, the included angle of the beveled blade can be up la 6^*: for Virgin paper,

|0142| Estimated economic comparison or non-switch heck product and tissue layered product

Non-swi ch (W$>&) tool r«sha }>en «g versus Ti$s«e-U» er*o: (Tt) Sys em

T o8r¾{ is $1§0δ>δ0 to ros w o Slit $h¾e ftp tissue separator esting can fee resharpe ssKt 6 time . ΐ,δδθ.δθδ Ι,Τθδ,Οόδ Fer es sfpening

Tool cost $11000 1 us«& wiih § sl persftgs

48,000,00$ tota revol tion Site 38,908,000 Total m mftsmam

14" repea f ool - 117'

Tissue $130 .¾m 1 ,«,00 11 ,000,00 Cost p r toot

* tamos 12,888,06 Cost for S sharpening* with tmgU

,003388 per square foot 23,803,08 T l s Cost for toot

4S,S83,08S Total ws m of fset pet tool life

23,808,00 $ §,§80.00 Comparison of toot i iv¾s

8 0.083385 Tlssye Cost per toot

0 $ 4¾§S1<00 Total tissue c st at N58 tool lit 2S_t«,00 $ 48,881,68 Total cost for tool and tissue Μ& ίΜ 0 Savings

Other sa ings not included

Ship ing costs to

e st rrser ack sit^

The expander of the present Invention simultaneously feeds two layers of expended paper as compared to a separator sheet design feeding one layer of expanded sheet ma e ial and one separator sheet la er. Consequently, the wrapping operation using the system of the present invention is twice as fast as that ef the separator sheet system ef the prior art,

144] B virtue of doubling of the speed of packaging, labor costs are reduced by about 50%.

10146] The product of the present Invention requires less material to ap an object because of the resistance to refraction and flattening of the cells, and the improved performance under compression,

[0148] The process of the present Invention Is less complex and easier to use because it eliminates the need to use a se ar tor sheet T e eliminaton of the separato sheet reduces the cost of the product enerally by out 30%.

(0149j Maintains better stretch duo to the interlocking

|0150) As described above _;. the interlocking of adjacent sheet ot expanded slit sheet material resists

retraction of the expansion of the sheets.

10150) ZxpzrxM silt sheet material Products

[0151] There are multiple end uses of the expanded slit sheet material. The first is as a wrapping product The stretching process traps the goods firmly due to the inherent desire for the slit sheet material to return to its fiatfundexpanded position. This paper fiber memory assures a tight fit. The method of wrapping of the interlocking cells maintains the locked position that maintains the strain on the fibers fighting to return to its original position.

(0152] A second use is as a void ll product Since the materia! will not be wrapped and merely laid into the box to till empty space, the inherent fiber memory creates an adverse effect by decreasing the angle of the hexagonal cell thus reducing the overall void III volume. To overcome this it Is necessary to super- stretch the slit sheet materia! so that the fibers are slightly torn thereby eliminating or minimizing the fiber memory.

(01531 The slit sheet expander paper tension or gearing can be adjusted for either approximately 10 to 20 percent less than full stretch tor the wrapping method so that the packer performs the final stretch, in the frrst case as a wrap, it would be best If the ceils are not fully stretched so that the final stretch, performed by the packer, makes a more secure fit. Expansion would be to maximum of 90% of maximum stretch. This retraction helps the wrapping method by enhancing the interlocking effect, but diminishes the value of the void fi method. B way of contrast, in the case of a void fill product the desired end result is achieved when the eels are super stretched to remove the desire for the cells to refract hack to the Hat. As a void fill the super stretch would he approximately 101 to 11 percent depending upon the paper used. As a void fill method requires the product to remain at its maximum loft without the help of the packer.

[0154] The relative take-up speed and resistance speed of the feed rollerfs) are adjusted to determine the degree of expansion that is being produced by the expansion equipment The expansion device can be of the type disclosed In US Patent 5,782,735.

[0155] While the invention has been described In terms of several preferred embodiments.: it should be

understood that there are many alterations: permutations, and equivalents thai tall within the scope of this invention. It should also be noted loaf there are alternative ways of implementing both the process and apparatus of tha present invention. For example.: steps do aol necessarily need to occur In the orders shown in the accompanying figures, and ma be rearrsapsd as appropnate. II Is therefore intended that the appended claim incl de all soon alterations; peomttattoos, and equivalents as tali within the true spirit end scope of the present Invention.

[0156] All references.: including publications: patent applications, aad patents, ailed herein are hereby

incorporated by reference to the same extent as If each reference were Indwldoatty aad specifically Indicated Io be Incorporated by reference and ware set forth la Its entirety herein.

|01δ?] The use of the terras "a" aad "art* and W and similar references la the context of ihla disclosure {especially In the context of the fallowing claims) are la be construed to cover both the singular and the lural:_: aaless otherwise indicated herein or clearly contradicted by context At! methods described herein caa be performed la any suitable order unless otherwise Indicated herein or otherwise clearly contradicted by context. The use of any and all example , or exemplary language (e .g., such as, preferred, preferably) provided herein. Is intended mereiy to further illustrate the content of the disclosure aad does not peso a limitation oa the scape of the claims. No language In the specification should oe ceastrued as indicating any nomclalmed element as essential to the practice of the present disclosure,

(0158] Multiple embodiments are described herein, including the best mode known to the inventors for

practicing the claimed Invention. Of these., variations of Ilia disclosed embodiments w! become apparent o those of ordinary skill in the art; upon reading the foregoing disclosure. The inventors expect skilled artisans Io em loy such vacations a appropriate (e,g„ altering or combining features or embodiments), and the Inventors Intend for the invention to be practi d otherwise than as specificall described herein.

(01591 Accordingly. Ihla invention includes all modifications and equivalents of the subject matter recited la the claims appended herein a permitted by applicable law, Moreover, any combination of the above dasaribed elements in all possible variations thereof is encompassed by the invention unless otherwise Indicated herein or otherwise clearly contradicted by context.

(0160] The use at individual numerical valaes are stated as approximations as though the values were

preceded by the word "abouf , ''substantially^*, or ''approximately;' Similarly, the numerical values In the varleas ranges specified in this application, unless expressly indicated otherwise, are stated as approximations as though the minimum and maximum values w!ttao Ibe sfatad ranges were both preceded oy the word "about". ¾uostant!aiiy^':', or "approximately,^* In this manner, vacations above aad below the slated ranges can he used to achieve substantially the same results as values within the ranges. As used herein, the leans "about , "substantially \ and "apprex!oiaie!y* when referring to a numerical value shall have their plain and ordinary meanings to a person of ordinary skill in the art to which the disclosed subject matter is most closely related or the art relevant to the range or element at issue. The amount of ro deni g from the strict numerical boundar depends upon many factors. For example.: some of the factors which may ho considered include the criticality of the element and/o the effect a given amount of variation will have on the performance ot the claimed subject matter, as well as other oons&rai!oos known to t ose of skill in the ad. As asad herein, the use of differing amounts oi significant digits for different numerical values is not meant to limit how !he use of tie words "about", ''substantially^* or "approximately" will serve to broaden a particular numerical value or range. Thus, as a general matte , "abouf . ¾bslanllally^!:, or "approximately" broaden the numerical value. Also, tha disclosure ol ranges is intended as a continuous range including every value t een the minimum and maximum values plus the broadening of the range afforded by tha use of the term ¾bouf "substantially", or "approximately". Thus, recitation of ranges of values herein are merely intended to serve as a shorthand method of referring IndlviduaHy to each separate value falling within the range unless otherwise Indicated herein _: end each separate value is incorporated into the specification as if It were Individually recited herein. To the extent that determining a given amount of variation of some the factors such as the chfiealify of the slit patterns, paper width dlffarenllal pre - and post- expansion, paper weights and type, as well as other considerations known to those ol skill to the su 10 which the disclosed subject matter most closely related or the art relevant to the range or element at Issue will have on the permanence rat claimed subject matter, is not considered to be within the ab!fy of one of ordinary skill in the art or Is not explicitly stated in the claims, then the terms "about", "substantially", sad

Approximately" should be understood to mean die numerical value, plus or minus 10%,

71 K is to ba understood that any ranges, ratios and ranges of ratios that can be formed by, or derived franc any of she data disclosed herein represent furthar embodiments of the present disclosure and are Included as pari, of the disclosure as thoug they ware explicitly set forth. This iaeiaues ranges that oau be formed that do or do not include a finite upper and/or lower boundary. Accordingly, a person of ordinary skill in the art most closely related to a particular range, ratio or range of ratios will appreciate that such values are unambiguously derivable Irani the data presented herein.

Claims

1- he method of producing at least a pair of Interlocking dj cent layers of a paper packaging product, said pair of interlocking adjacent layers being formed of a first sheet of slit paper and a second sheet of sit paper,

sas f first sheet of slit paper having a first silt pattern and said second sheet of sll paper having said first slit pattern,, said l pattern upon expansion, forming cells that include land regions that are inclined with respect to the plane of the unexpended sheet,

slitting said first sheet of sll paper and said second sheet of sll paper to produce sis that upon expansion, produce fends regions of said first sheet that have angles of inclination in the range for 50 to 85 degrees,

orienting and expanding said second sheet of slit paper, and causing said tend regions to have an inclination angle in the range from 130 to 96° relative to said first s eet of slit p pe ,

layering said first expanded sheet on said second expanded sheet and causing said tend regions of said first expanded sheet to interlock with said second sheet.

2^» The method of claim 1, wherein said siting of said first sheet and said second sheet forms a substantia^ straight line cut along one edge of the si and an angled cut along th other edge of the sll. thus forming a wedge shape that B wider on a first side of the blade entry point that en the other side of the blade entry point.

3- The method of claim 1 , wherein said expanding of said first sheet and said second sheet is In the range from about 10 to 20% less than the maximum expansion of each of said first sheet and said second sheet.

4~ The method of claim 1 , wherein said expanding of said first sheet and said second sheet is in the range from about 100 to 110% of the maximum expansion of each of said first sheet and said second sheet. S- The method of claim 1 _> wherein said silting of sal ) first sheet and said second sheet forms a straight line cut along one edge of the slit and an a gled cot along the other edge of th all.

8- The method of claim 1 , wherein said angfe of inclination of said first sheet and said angle of inclination of said second sheet are consistent along the length of said first sheet and said second sheet.

7- The method of claim 1 , wherein said angfe of she!lnation of said first sheet and said angle of inclination of said second sheet along the length of said first sheet and said second sheet have less than about 20% switch back effect.

8- The method of claim 1 _:;. wherein said angle of lielination of said first sheet and said angle of inclination of said second sheet along the length of said first sheet and said second sheet have less than about 10% switch back effect.

9- The method of claim 1 , further comprising the step of forming slits in said first and said second sheet of slit paper using beveled blade having an ficlyded angle the range from 1 to 6 degrees,

10- The method of claim 9_; wherein said beveled blade has a first side that forms an angle of about 90 degrees with respect to the plane of the paper being slit

1 1, The method of claim 1. where! n upon expansion, said angle of inclination of said first sheet Is in the range from 55 to 75 degrees, and said angle of inclination of said second sheet Is In the range from 105 to 126 degrees.

12- The method of claim 1 , further comprising the steps oh

winding in a first direction, said first sheet of slit paper hto a first roll,

winding in the reverse direction with respect to said first direction, said second sheet of slit paper into a second roll,

feeding said first sheet of slit paper from said roll, clockwise or counterclockwise into a first expander,

simu&aneously feeding said second sheet of si paper from said roll into a second expander, the direction of rotation of said second sheet of sll paper being the same direction that said first sheet of sll is fed into said first expander,

expanding said first sheet of sll paper; said first slit pattern causing said fend regions to have an inclination angle in the range for SO to 85 degrees,

expanding said second sheet of slit paper, said first slit pattern and causing said land regions to have an Inclination angle in the range from 130 to 95 degrees, layering said first expanded sheet on said second expanded sheet, and

causing said land regions of said first expanded sheet to interlock with said second sheet,

13- The method of claim 1 , further comprising the step of forming slits in said first and said second sheet of slit paper using a beveled blade against a rotating anvil, said beveled blade having an included angle in the range from 1 to 6 degrees,

14- The method of claim; 1 _t wherein open expansion, said angle of inclination of said first sheet B in the range from 55 to 70 degrees, and said angle of inclination of said second sheet Is in the range from 125 to 110 degrees,

15~ The method of claim 1 further comprising forming said first silt pattern and said second si pattern by silting with blade against a rotating anvil, said blade having an angle included angle In the range from 1 to 3 degrees., and wherein said paper is recycled paper, thereby producing an inclination of said first sheet and an angle of inclination of said second sheet that is substantially consistent along the length of said first sheet and said second sheet. 18·· The method of claim 16_t wherein said anvil a soft anvil and said blade cuts through said paper and into said anvil.

17^» The method of claim 1 wherein one of said first sheet of sill paper and said second sheet of slit paper is Kraft paper., and the other of said first sheet of sli paper and said second sheet of si paper is soft paper.

18- An apparatus for producing at feast a pair of non-nesting adjacent layers of a paper packaging product, first means for forming In a plurality of roils of sheet material , 01 s having a pattern which upon expansion of said roll of sheet material having slits, yields cells having fend regions, said land regions having an Inclination angle in the range from about 50 to 85 degrees,

said first means including blades having an included angle in the range from about 1 to 8 degrees, and causing a wedge effect at one edge of each of said slits,

second means for drawing clockwise into an expansion region, a first of said plurality of rolls of sheet material having sis,

third means for drawing counterclockwise Into an expansion region, a second of said plurality of rolls of sheet material having slits,

fourth means for simultaneously expanding each of a plurality of sheet material having slits, expanding said first of said plurality of rolls of sheet material having slits, and causing said land regions to have an inclination angle in the range for SO to 85 degrees, and expanding said second of said plurality of rolls of sheet material having sis, and causing said land regions to have an inclination angle In the range from a bout 130 to 95 degrees.

Fifth means for layering said first expanded sheet on said second expanded sheet _s and

sixth means for causing said land regions of said first expanded sheet to interlock with said second sheet, said angle of inclination of said first sheet and said angle of inclination of said second s eet being consistent along the length of said first sheet and said second sheet

19- A paper packaging product comprising:

a first sheet of slit paper having a slit pattern that upon expansion, a plurality of sis form a plurality of cells that Include land regions that are inclined wit respect to the plane of the u ex end d sheet,

said slits having a wedge effect that Is sufficient to cause upon expansion, the fends regions of said sheet to have a substantially consistent angle of inclination along the entire tength of the expanded sheet and the lands regions, said s cfination angle being In the range from 60 to 85 degrees,

20» The paper packaging product of claim 19_» further comprising a second sheet of slit paper layered on said first sheet of silt paper, said first sheet and said second sheet being expanded to form a pair of interlocking adjacent expanded sheets of sit packaging material,

said sheets of slit packaging material having a slit pattern that upon expansion, a plurality of slits that form a plurality of cells having land regtons that are inclined with respect to the plane of the u expende sheet,

said slits having a wedge effect that is sufficient to cause upon expansion, the tend regions of said first sheet to have an inclination angle h the range from about 60 to 86 degrees along the length of the expanded sheet,

the second of said pair of interlocking adjacent expanded sheets having an inclination angle in the range from 130 to 96 degrees,

said first expanded sheet being layered on and rtterlocxing with said second expanded sheet.