MXPA00009951A - Non-symmetrical knife apparatus and cutting method. - Google Patents

Abstract

A novel knife apparatus and method are disclosed for cutting a plurality of articles from a sheet or web of material. The knife can be formed in or secured to the outer surface of a rotary die cutter. The knife includes a first cutting member having a first end, and second and third cutting members joined to the first end of the first cutting member. The second and third cutting members are arranged relative to one another to form an arcuate section which intersects with the first cutting member to form a general non-symmetrical configuration. A unique knife profile enables two adjacently arranged articles to be cut simultaneously from a sheet or web of material with zero clearance between at least a portion of the outer peripheries of the two articles.

Description

HEAVY WORKING BLADE APPARATUS AND CUTTER METHOD This patent application is a continuation of part of the co-pending United States of America patent application serial number 09 / 020,134 filed on February 6, 1998 and of patent application number 08 / 655,506 filed May 30, 1996, now abandoned .

BACKGROUND OF THE INVENTION Technical Field This invention relates to a novel knife method and apparatus for cutting articles from a sheet of fabric. In one aspect, this invention relates to a blade having a unique configuration which can be formed in or secured to the outer surface of a rotating die cutter to cut a plurality of articles from a sheet or fabric of material with a clearance of zero. between at least parts of the outer peripheries of the two adjacent articles.

Background Many different kinds and types of articles are currently manufactured which involve cutting or stamping a plurality of identically shaped articles of fabric or sheet of elongated material. The fabric or sheet of materi can be a single layer or a laminate formed of two or m layers. In the production of such articles, cut waste is usually present, and it is beneficial from a cost point of view to minimize such waste. Clipping waste is defined as all material which does not constitute a finished item. This includes the waste located one side of the periphery of each item as well as the waste cut from the inside of an item. Even when scrap waste is kept to a minimum, its presence causes problems in the sense that it has to be separated and taken out of the finished items. Scrap waste should also be handled if it is to be disposed of, reclaimed or recycled properly.

INTRODUCTION TO THE INVENTION For articles configured in a unique way that have at least one non-linear angle, it is very difficult to completely get rid of the clipping waste. However, it is possible to minimize the amount of waste cut and design the waste to have a certain profile so that it can be easier to handle when separated from the finished items.

One way to minimize waste clipping is to design the cutter blade to have a profile so that the cutter will simultaneously cut adjacent items from a fabric or sheet of material by arranging the two or more items through and / or Along a leaflet woven of material, so that the articles are joined by a common peripheral segment, a reduction in waste can be obtained.

Now, a novel blade has been invented which has a unique configuration formed in or secured to the outer surface of a rotating die cutter for cutting a plurality of articles from a sheet or fabric material with zero clearance between at least a portion of the fabric. outer peripheries of two adjacent articles.

It is an object of the present invention to provide a blade and a method for cutting articles a sheet or fabric of material.

A specific object of the present invention is to provide a blade having a unique configuration which can be formed in or secured to the outer surface of a rotating die cutter to cut a plurality of articles from a sheet or fabric of material with a clearance of cer between at least a part of the outer peripheries of adjacent articles.

Another object of the present invention is to provide a blade which has a bifurcated configuration which can simultaneously cut a portion of the outer peripheries of two adjacent articles.

A further object of the present invention is to provide a blade which has at least three cutting members intersecting in a common place.

Yet another object of the present invention is to provide a blade which has an economical form m of cutting a plurality of articles from a woven sheet of material.

Still further, an object of the present invention is to provide a blade of material having a thickness of at least .001 inches (about .025 millimeters).

These and other objects and advantages of the present invention will become more apparent in view of the following description and the accompanying drawings.

SYNTHESIS OF THE INVENTION Briefly this invention relates to a blade formed in or secured to the outer surface of a rotating die cutter for cutting a plurality of articles from a sheet or fabric of material. The cutter includes a first cutter member having a first end and the second and third cutter members attached to the first end of the first cutter member. The second and third cutter members are arranged one relative to another to form an arched section which cooperates with the first cutter member to form a non-symmetric configuration. The cutter and the method of the present invention provide a specified cutting edge blade thickness and a specified blade configuration for a rotating die cutter and cooperation with a specified proximity to a rotating yunq. The unique configuration allows articles to be cut simultaneously from a sheet or fabric of material with a clearance or clearance of zero between at least a portion of the outer peripheries of two adjacent articles.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a rotating die cutter showing a pair of knives ch 1 having an hourglass profile and arranged end-to-end so that a common section of the blade can simultaneously cut a part of the knife. the outer peripheries two adjacent articles.

Figure 2 is a cross-sectional view of one of the blades shown in Figure 1 taken along line 2-2.

Figure 3 is a top view of an absorbent article, such as a sanitary napkin or a panty liner and having a central longitudinal axis X-X which has been cut by the rotary die cutter.

Figure 4 is a side view of the absorbent article shown in Figure 3 exhibiting several distinct cap.

Figure 5 is a schematic top view d area within the dotted circle shown in the figure showing the fork of the blade.

Figure 6 is a schematic top view of a blade profile located within the area of the dotted circle shown in Figure 5.

Figure 7 is a part of the view shown in Figure 6 showing a rectangle drawn around the bifurcation point of the blade.

Figure 8 is a schematic view of an alternate knife perf located within the area of the dotted circle shown in Figure 5.

Figure 9 is a part of the view shown in Figure 8 showing a rectangle drawn around the bifurcation point of the blade.

Figure 10 is a schematic view of an alternate knife perf located within the area of the dotted circle shown in Figure 5.

Figure 11 is a part of the view shown in Figure 10 showing a rectangle drawn around the bifurcation point of the blade.

Figure 12 is a schematic view of another alternate blade profile located within the area of the dotted circle shown in Figure 5.

Figure 13 is a part of the view shown in Figure 12 showing a rectangle drawn around the bifurcation point of the blade.

DETAILED DESCRIPTION The novel blade of the present invention operates to provide a specified edge cutter blade thickness and a specified blade configuration for a rotary die cutter in cooperation with a specified proximal to a corresponding rotating anvil. The specified cutting edge blade thickness and the specified blade configuration have been found to provide significant advantages of less surface area, less pressure, and structural integrity to produce a prolonged blade life.

It has been found that the specified cutter edge blade thickness should be in the range of about 0.001 to 0.003 inches. At a cutter blade thickness below 0.001 inches, the blade will cut, but it has been found that the blade will lose the integrity of the cutter member. At a cutter blade thickness of less than about 0.001 inches, it has also been found that the blade is difficult to machine in a proper configuration. At a cutter blade thickness of more than 0.00 inches, the blade will cut, but it has been cut. found that the blade will become prematurely blunt and will wear out quickly. At cutter blade thicknesses above about 0.003 inches, the surface of the blade requires too much pressure, and it wears out very quickly. Excessive pressure flattens the cutting edge, and even more pressure is required to cut.

It has been found that the specified knife configuration should be in the range of about 20% to 40 based on the ratio of the cutter surface area to the overall surface area, as fully described in the detailed description that follows. At a cutting edge knife configuration down from about 20% cutter surface area to overall surface area, it has been found that the cutter does not have a preferred cross sectional thickness to provide sufficient structural integrity. At a configuration of cutting edge cutter down about 20%, the cutting edge surface area to the overall surface area has been found to cut, but will have a reduced blade life. The longevity of the blade is of key importance in the business of producing sanitary towel articles from a mobile layered sheet of woven material in a rotary die cutter. At a configuration of cutting edge knife above about 40% the surface area of cutting edge to the overall surface area it has been found that the blade hits against the anvil, at a point of putting a dent in the anvil. It has further been found that the surface areas above the specified surface area require more pressure, and the super pressure produces a flattening of the cutting edge of the cutter to make it blunt, thus accelerating an inefficiency problem.

The novel blade of the present invention further operates to provide a specified blade height for a rotary die cutting blade cooperating with a corresponding rotating anvil. The height of the specified cutting edge blade has been found to "explode" or "jump back" a sanitary article that is to be cut from a layered sheet, while not cutting through the thickness of the sheet. sheet in layers. The blade of the present invention operates to cut only about 80% to 90% of the thickness of the sheet in layers. The rest of the layered sheet, for example 10% to 20% of the layered sheet cut by the cutting edge of the blade, will explode to form the discrete sanitary napkin article. In this manner, the blade of the present invention is I have found that it has a longer life in the cutting edge.

The longevity of the blade is critical in the business of producing sanitary ware articles from a mobile layered sheet of supply material to a rotating die cutter. The blade of the present invention provides millions and millions of cuts at the speed to produce the sanitary napkin articles from a mobile layered sheet. The moving sheet of the layer material moves at speeds of 500 feet per minute higher. The life of the blade preferably runs at millions of rotations of the rotary die cutter.

The precision of the thickness of the cutting edge, the height and the configuration have also been found to be critically important for producing sanitary ware articles from a mobile layered sheet of supply material in a rotary die cutter. The high speeds of the mobile layer sheet and the extended life of the blade provide for the novel blade of the present invention. It has been found that the blade of the present invention contains the specified blade thicknesses., blade height and blade configuration provides reduced surface area, less pressure, less wear and a significantly longer blade life.

The specified blade configuration, in aspect, preferably provides a specific geometry including a linear section attached to an arcuate section, more particularly described in the detailed description that follows. The specific geometry of the specified knife configuration of the present invention provides a significantly reduced surface area on the blade cutting area and on the blade joints. The blade of the present invention reduces the surface area at the joint points significantly reduces the pressure points, and significantly increases blade life.

The important key to the life of the longer blade is facilitated dramatically when the tip of the blade is held out from making an actual contact with the anvil. Holding the blade away from the anvil requires an effective cutting precision over the full blade thickness, height and pattern. If the thickness of the cutting edge on the part of the blade or pattern configuration is not precise, the die should be adjusted downward toward the anvil, thereby producing a higher pressure on the edge of the blade and a decreased die life.

The blade of the present invention provides a precision cutting tool, a thin cutting instrument. The blade of the present invention as a precision cutting tool provides significant material savings over the order of in excess of one million dollars per year (1998 dollars) in savings of sheet material layers. The additional savings are produced by the higher rotary die cutting speeds, the lower labor-free times of the rotary die cutter manufacturing operation and the reduced blade sharpening expense.

Referring to Figure 1, there is shown rotary die cutter 10 having an outer periphery 12 which is circular in configuration. Secured or mounted on the outer periphery 12 are two or more blades 14 which are shown having a sand clock configuration and a central longitudinal axis XX which circumscribes the outer periphery 12 of the rotary die cutter 10. The blades 14 are arranged in an that these are close to each other and have a common edge 16 located between them. It should be noted that the blades 14 can be any type of desired configuration including a square, a rectangle, a circle, an ellipsoid, a sand clock or an oval. The blades 14 can be used to cut a sheet of material that includes a single layer or a fabric material which includes two or more layers. For purposes of this detailed description, the blades 14 will be described as being secured or mounted on a rotary die cutter but the blades 14 may be used by themselves or may be attached to a movable member or some other type of rotating or reciprocating mechanism.

For ease of understanding, the present invention will be described in relation to cutting or punching or plurality of absorbent articles such as sanitary towels, panty liners or incontinent garments from a sheet or fabric of elongated material.

Referring to Figure 2, the blade 14 is shown integrally formed with the rotary matrix cutter 10 and extending outwards in the radi direction from the outer periphery 12. The blade 14 includes a handle 18 which terminates in a blade 20 The blade blade 20 has an inner edge 22 and an outer edge 24, or both of which may be tapered or inclined towards each other as to form a vertex 26. The apex 26 may be a sharp point or this may be a surface Flat co is seen under a microscope. The overall thickness (t) is about .0012 inches to about .0018 inches (about .0305 millimeters to about .0460 millimeters) when it is used to cut an absorbent article, such as a panty liner. As the pant knife 20 wears out from use, it is possible to re-grind one or both of the surfaces and 24 to maintain the desired thickness (t) of the apex 26.

As mentioned above, even when the blade is shown to be integrally attached to the rotating die cutter 10, the blade 14 can also be mounted on a plate which is then screwed, bolted, removably attached to the rotary die cutter 10.

Referring to Figures 3 and 4, the blade is designed to cut an article 28 from an elongated sheet of a material fabric. The sheet or fabric of material can be a single layer of material, or it can be formed of two or different, different or identical layers which can be stacked, assembled, laminated or vertically joined together When two or more layers are present, Layers can be laminated or joined together by heat, pressure, heat and pressure rubber, adhesive, thermal bonds, mechanical bonds, or chemical unions. The articles 28 can have almost any conceivable configuration. For the purposes of illustration, article 28 is shown as an elongate pant liner having a central longitudinal axis X-X. However, it should be noted that this invention is not limited to this particular form. The materials which can be cut by the blade 14 include paper, plastic, film, thermoplastic film, absorbent eraser, coform, foam, pulp, wood, cardboard, wood or any other material or combination of materials known therefrom. The coform consists of a carrier sheet bonded with yarn with a blend of pulp fibers and extruded polypropylene which is available from Kimberly-Clark Corporation having an office at 401 N. La Street, Neenah, Wisconsin 54956. For discussion purposes only, Article 28 will be described as an absorbent article such as a sanitary napkin, a panty liner or an incontinent garment. It should be noted that blade 14 can cut both the linear and linear edges, curves, arched shapes or circles. Items that have a straight or linear segment such as a square rectangle or parallelogram profile tend to be easier to nest and cut into a line-to-line shape.

As shown in Figure 1, blades 14 are formed on a portion of the outer periphery 12 d solid-matrix die cutter 10. The blades 14 are arranged in an end-to-end configuration around the outer periphery 12 of the cutter. rotating die 10 cooperate with other blades 14 (not shown) which form a row of blades 14 which extend completely around the outer periphery 12. The number of blades 1 that is present will depend on the circumference length of the cutter matrix 10 and the size and shape of the individual blades 14. The blades 14 can be machined onto the axis of the die cutter 10 so that they appear in an off-center and / or side-by-side arrangement. Multiple blades 14 can to be machined around the periphery 12 and across the width of the die cutter 10. For example, 2, 3, 4 or 5 blades 14 can be formed around the periphery 12 and through s of the width of the rotary die cutter 10 so that a plurality of articles can be cut for each revolution of the die cutter 10. It should be noted that when the knives 14 have an uneven profile it can be advantageous to nest the knives 14 in a pattern across the width of the die cutter 10 so as to be able to cut additional articles.

Referring again to Figures 3 and 4, absorbent article 28 is shown which is designed to be adhesively attached to the inner crotch portion of the wearer's undergarment. Such articles consist nominally of several layers of different materials which are arranged vertically. The layers, from the upper to the lower pair, may include a liquid permeable cover 30, an absorbent 32, a liquid impermeable separator 34, a garment fastening adhesive 36 secured to a lower surface of the separator 34., and a removable peel strip 38. Other layers, such as a transfer layer, a transmission layer, a layer containing superabsorbent materials, or additional absorbent layers may also be used. The various layers can be stacked assembled, laminated and / or joined together vertically to form a multilayer fabric of material from which the articles 28 can then be cut or punched. L several layers can be joined together by using heat, pressure, heat and pressure, construction adhesive, hot melt glue, thread sewing, ultrasonic bonding, mechanical bonding, thermal bonding, chemical bonding or a combination thereof.

The liquid-permeable cover 30 is designed to make contact with the wearer's body and may be constructed of a woven or non-woven material which is easily penetrated by body fluid. The liquid permeable cover 30 can be formed of either natural or synthetic fibers. Suitable materials include carded and bonded fabrics of polyester, polypropylene, polyethylene, nylon or other heat-bondable fibers. Other polyolefins, such as polypropylene and polyethylene copolymers, linear low density polyethylene, finely perforated film fabrics, and network materials also work well. A preferred material is a composite of a perforated thermoplastic film placed on top of a woven fabric. Such composite material can be formed by extruding a polymer onto a woven fabric of spunbonded material to form an integral sheet. An example of this is a perforated thermoplastic polyethylene film bonded to or spunbonded material. Spunbonded is a non-woven material which is manufactured and sold commercially by Kimberly-Clark Corporation having an office located at 401 North Lake Street, Neenah, Wisconsin 54956. The non-woven sheet / perforated film exhibits a smooth appearance and soft to the touch. This material is relatively soft and will not go to the wearer's skin and still has a cushioning sensation due to its volume.

Another useful material such as liquid permeable cover 30 is a woven fabric bonded with polypropylene yarn. This yarn bound fabric can contain from about 1 to about 6 percent bleaching agent, such as titanium dioxide (TiO2). calcium carbonate (CaC03) to give it a clean, white appearance. A uniform thickness of the spinning bond is described because it has a sufficient strength after being punctured, to resist tearing being pulled and separated during use. The most preferred polypropylene fabrics have a basis weight of between about grams per square meter (gsm) to about 40 grams per square meter. An optimum weight is between about 3 grams per square meter to about 40 grams per square meter.

The absorbent layer 32 may be present as a single layer or as two or more layers. The absorbent 32 may be formed of various natural or synthetic fibers such as wood pulp fibers, virgin cellulose fibers, regenerated cellulose fibers, cotton fibers, swamp moss, or a mixture of pulp and other fibers. The absorbent layer 32 can also be formed of a fine pored fabric such as an air-dried and wet-laid fabric or a non-creped and air-dried tissue (UCTAD) having a base weight of approx. 30 grams per square meter to around 1 grams per square meter. The air dried and creped tissue can be prepared by a process as described in United States of America patent number 5,048.5 granted to Crook et al. On September 17, 1991. The tissue dried by air and The non-crepe is described in United States Pat. No. 5,399,412 issued to Sudall et al. on March 21, 1995. Each of these patents is incorporated by reference and is made a part hereof. The absorbent layer 32 may also include other known cellulose materials such as cellulose fibers, rayon fibers, cellulose sponge, hydrophilic synthetic sponge, for example polyurethane and the like.

The liquid-impermeable separator 34 allows passage of air or vapor from the absorbent article 2 while blocking the passage of fluid from the body. The liquid impermeable part 34 is made of a material having these properties. The separator impermeable to liquid 3 can also be constructed of a material that blocks the passage of vapor as well as fluids. A good material from which the separator 34 can be constructed is a micro-etched polymeric film, such as polyethylene or polypropylene. Two-component films can also be used. A preferred material is a polyethylene film. More preferably, the separator 34 is made of a polyethylene film having a thickness in the range from about 0.5 millimeters to about 2.0 millimeters It should be noted that the adhesive construction can be used in article 20 to attach and join the various cap together. For example, the construction adhesive can be used to attach the liquid impervious separator 34 to the absorbent or to attach the absorbent 32 to the liquid permeable cover 30. The presence of such an adhesive construction and the amount used will depend on the specifications of the adhesive. manufacturing. L useful construction adhesives are sold commercially by National Starch and Chemical Company, which has an office located at 10 Findeme Avenue, Bridgewater, New Jersey 0880 The absorbent article 28 can also include one or more elongated areas or strips of garment fastening adhesive 36 secured to the lower surface of the liquid impervious seam 34. The garment fastening adhesive 3 functions to attach the article 28 to the inner part of the garment. l crotch of the wearer's undergarment. The garment fastening adhesive 36 allows the absorbent article 2 particularly a sanitary napkin, a panty liner to an incontinent garment, the suitably aligned to be retained relative to the vaginal opening of the wearer so that a garment can be obtained. Maximum fluid protection.

The garment fastening adhesive 36 may cover the entire lower surface of the liquid impermeable separator 34 or only a part thereof. The garment fastening adhesive 36 may consist of a swirl adhesive pattern may be one or more strips of adhesive. The garment fastening adhesive 36 may also consist of a plurality of adhesive beads which are arranged randomly or evenly on the outer surface of the separator 34. When in the form of a strip, the garment fastening adhesive 36 may be applied to the adhesive. aligned along the central longitudinal axis XX of the absorbent article 28. Alternatively, the fastening adhesive d garment 36 may be present as two or more longitudinal strips spaced apart. The garment fastening adhesive 36 is of such a nature that it will allow the wearer to remove the absorbent article 28 and reposition it on the wearer's undergarment if necessary. A hot-melt adhesive which works well as a garment fastening adhesive is sold commercially by National Starch and Chemical Company, which has an office located at 10 Findeme Avenue, Bridgewater, New Jersey 08807 to protect the garment fastening adhesive from the contamination before use, the adhesive 36 can be protected by a releasable peeling strip 38. The peel strip 38 can be a white kraft paper coated on one side so that it can be released from the adhesive 36. coating can be a coating of silicone, such as commercially available silicone polymer from Akrosil q has an office located at 206 Garfield Avenue, Menash Wisconsin 54952. Peeling strip 38 is removed by the user prior to clamping the absorbent article 28 to the inner crotch pair of the undergarment.

Referring to Figure 5, there is shown a schematic top view of the blade 14 exhibiting the common edge 16. The blade 14 includes a first cutter member 4 having a first end 42. The first end 42 is shown as a dotted line for the purpose of understanding the invention better. The blade 14 also includes a second cutter member 44 attached to the first end 42 of the first cutter member 40. The cutter 14 further includes a third cutter member 46 also attached to the first end 42 of the first cutter member 40. It should be noted that by the word " "It is meant that the second and third cutter members 44 and 4 respectively, may be integrally held or formed of a material which forms the first cutter member. In addition, the word" attached "may include the clamping of the second cutter members. and third 44 and 4 respectively, to the first cutting member 40 by means of welding, mechanical bonding, thermal bonding, chemical bonding, or some other type of physical fastening. For best results, the second and third cutter members, 44 and 46 respectively, are preferably machined from a single piece of metal with the first cutter member 40. It should be noted that the entire cutter 14 is machined from the solid shaft of the die cutter 10.

The first cutter member 40 can be a linear member formed of ferrous or non-ferrous metal. Preferably the blade 14 is formed of tool steel. The first cutter member 40 should have a thickness ti of at least d about .0254 millimeters + .0050 millimeters, preferably has a thickness of between about .0254 millimeters + .005 millimeters to about .1270 millimeters + .0050 millimeters , more preferably from at least about .025 millimeters + .0050 millimeters to about .0762 millimeters .0050 millimeters. The second and third cutter members 4 and 46 respectively, can also be formed from a ferrous or non-ferrous target and are preferably formed from tool steel. The second and third cutter members 44 and 4 respectively, must have a thickness of at least d around .0010 inches + .0002 inches (at least around .0254 millimeters + .0050 millimeters). In addition, the second and third cutter members 44 and 46, respectively, should have a thickness of between about 0.0254 millimeters + .0050 millimeters to about .1270 millimeters + .00 millimeters, preferably a thickness of between about p at least .0254 millimeters + .0050 millimeters to around .07 millimeters + .0050 millimeters. The thickness t2 of the second cutter member 44 and the thickness t3 of the third cutter member 46 can be equal to the thickness ti of the first cutter member 40. It should be noted that, preferably, the first second and third cutter members 40, 44 and 46, respectively, all will have same thickness within .0050 millimeters, but may have different thicknesses. For example, the first cutter member may have a thickness ti which is greater than, equal to, or less than the thickness t2 of the second cutter member 44 and / or the thickness of the third cutter member 46.

As shown in Figure 2, the height of the specified blade above the surface 12 should be between about 1/8 inch and about 3/16 inch. At dimensions below 0.1 inch, the cutting edge is not capable of being machined, and the angle, for example, the 3-degree angle, of the blade leading to the cutting edge runs to the surface 12. Around the top of 1/4 of an inch the integrity of the blade structure is reduced. U moment arm is created by the height of the blade above the surface 12, and a larger moment arm has been found to crack in the steel. A larger dimension for the height of the blade makes an arm of moment m large, and cracks are sometimes observed at the intersection of surface 12 or down on steel.

The novel blade of the present invention operates to cut through only about 80% to 90% of the thickness of the sheet in layers. The blade is positioned at a specified vicinity of the anvil so that the blade operates to cut through only about 80% to 90% of the thickness of the layered web. The rest of the layered sheet material, for example 10 to 20% of the layered sheet is not cut by the cutting edge of the blade, but will snap to form the discrete sanitary napkin article. In this manner, the blade of the present invention has been found to provide a significantly longer knife life.

As shown in Figure 5, the second and third cutter members 44 and 46, respectively, are arranged one in relation to the other to form an angle alpha (there of between 180 degrees or less.) Preferably, this angle e of between about 15 degrees to about 180 degrees, more preferably, from about 30 degrees to about d 150 degrees and more preferably from about 45 degrees to about 120 degrees It should be noted that the angle alpha (o.) Can be measured in any part between the second and third cutter members 44 and 46 respectively, and may vary as the configuration of the second and third cutter members 44 and 46 diverge from each other.

The second and third cutter members 44 and 4 respectively, each have an arcuate section 48 and 50 respectively, which cooperates with the first cut member 40 to form a non-symmetrical configuration.

Referring now to Figure 6, one can see that each of the second and third cutter members 44 and 4 respectively, contains a linear section 52 and 54 respectively, which is integrally joined to the arcuate sections 48 and 50, respectively. In addition, each of the second and third cutter members 44 and 46 respectively has an inner edge 56 and 58 respectively. Both of the inner edges 56 and 58 can be joined to each other to form a circular arc 60 between the second third cutter members 44 and 46 respectively. The circular arc 60 may be formed of any given radius and may be in the form of a semicircular arc of about 180 degrees or may be in the form of an arc of less than 180 degrees. When the first, second and third cutter members, 40, 44 and 4 respectively, are machined from a single piece of metal, and advantageous to form the arc 60 with an arc of about 18 degrees.

Referring to both Figures 6 and 7, the second and third cutter members 44 and 46, respectively also contain an outer edge 62 and 64, respectively. Each of the first, second and third cutter members 40, 44 and 46, respectively, also it contains a center line AA, BB and CC, respectively, as shown in Figure 7 The center line for the first cutter member 40 will be a linear line while the centerline for the arc-shaped parts of the second and third cutter members will be 44 46 respectively will be arched curved. The centerlines BB and CC of the second and third cutter members 44 and 46, respectively, will be joined at a point "D" which has an equal distance between two vertically aligned points located on the outer edges 62 and 64 of the cutter members. second and third 44 and 46 respectively.

. The unique configuration of the blade 14 can be described as a ratio of the area of the cutting surface d of the blade 14 to the total surface area of a rectangle formed around the intersection of at least two of the first, second and third cutting members. 40, 44 and 46 respectively. The rectangle can be drawn around the intersection point "D" using the following procedure.

A rectangle 66 is formed by drawing a first line 68 through two points. Each of the points is located on one of the outer edges 62 and 64 of the second and third cutter members, 44 and 46, respectively at a location where the respective arcuate section 48 and 50 are joined to the respective linear sections 52 and 50. 54. By doing this, the point "E" is established on the outer edge 62 of the second cutting member 44, and a point "F" is established on the outer edge 64 of the third cutting member 46 It should be noted that the point "D" "It is at an equal distance between the points" E "and" F ". A second line 70 and a third line 72 are then drawn perpendicular to the first line 6 at the locations where the first line 68 crosses the outer edges 62 and 64 of the second and third cutter members 44 and 46 respectively. Lines 70 and 72 perpendicularly intersect the first line 68 at points "E" and "F" respectively. A fourth line 74 is then drawn parallel to the first line 68 so that it passes through a point "G" as shown in Figure 6. The point "G" represents the center of the smallest diameter circle which can be being inscribed at the intersection of the first cutter members 40 with at least one of the second and third cutter members 44 and 46, respectively, while the "H", "I", and "J" points are tangentially touched.

The point "H" represents a point on at least one of the arched sections 48 and 50 of the second and third cutter members 44 and 46 respectively. The pin "H" is located on at least one of the inner edges 56 and 58 which forms the circular arc 60. The pin "I" represents the intersection or meeting point of the outer edge 76 of the first cutter member 40 with any of the outer edge 62 of the second cutting member 44. If these edges 76 and 62 do not form a straight line, then each one is extended so that they intersect as shown in figure 6. The point "J" represents the intersection or point d encounter of the outer edge 78 of the first cutter member 4 with the outer edge 64 of the third cutter member 46. S these two edges 78 and 64, do not form a straight line, then each is extended so that they will intersect as shown in figure 6. The circumference of the circle then will make contact with the points "H", "I", and "J" tangentially, the center of the circle will be the point "G". When only the "J" point is known, a circle is drawn so that the outer circumference touches the "J" point as well as the tangentially touching the outer edge 62 or 64 and the inner edge 56 or 58.

Whether the outer circumference of the circle currently contacts the outer edges 76 and 78 of the first cutter member 40 or an extension of the outer edges 76 and 78 will depend on the angle and location at which the first cutter member 40 intersects the members. second and / or third cutters 44 and 46, respectively. For example, in Figure 6, the first cutter member 40 intersects the second and third cutter members, 44 and 4 respectively, at a location where the second cutter member 44 is identical in length to the third cutter member 46. E this configuration, it is necessary to extend the outer edges 76 and 78 so that they intersect the outer edges 62 and 64 in the places so that the circle having a central point "G" can be circumscribed. In contrast, the configuration shown in Figure 8 shows the first cutter member 40 being off-center relative to the second and third cutter members 44 and 46. In this configuration, point "I" is located at the point where the outer edge 76 finds the outer edge 62 and the point "J" is located at the point where the outer edge 78 intersects the outer edge 64. The establishment of the circle should now be understood in relation to the different configurations which are possible for the blade 14.

Referring again to FIGS. 7, it should be noted that when the first cutter member 40 equally divides the second and third cutter members, 44 and 46 respectively, it forms a "mirror image" along the longitudinal center line A-A. By "mirror image" it means that the upper half of the blade 14 is a reflection of the lower half of the blade 14. The entire image of the blade 14 is very similar to a tuning fork which can be used for refine musical instruments. In Figure 7, the center line A-A of the first cutter member 40 intersects the point "D", the point where the center lines B-B and C-C of the second and third cutter members, 44 and 46, respectively, meet.

Returning to the formation of rectangle 66, fourth line 74 will be drawn parallel to first line 68 will pass through point "G". A fifth line 80 then drawn parallel to the fourth line 74 and at a distance of the fourth line 74 equal to the distance between the first fourth lines, 68 and 74, respectively. It should be noted that when the rectangle 66 is formed, both the fourth line 74 and the fifth line 80 will be located on the same side of the first line 68. The first line 80 will be pulled so that it intersects the second and third lines 70 and 72, respectively, to form points "K" and "L". Rectangle 66 will then encompass an area joined by points "E", "F", "L" and "K". This bonded area is mentioned for the purposes of this detailed description of the present invention as the total surface area of the rectangle 66.

For clarity the rectangle can be mentioned as a rectangle drawn on the non-symmetrical configuration formed by a first rectangle line between each of the two corner points of the rectangle located on the outer edges of the second and third cutter members respectively, in one place wherein the respective arcuate section is attached to the linear section, a second rectangular side line and a third rectangular line laterally perpendicular to the first rectangle side line in one of the two rectangle corner points and extending a distance through of a central line placed where the second cutter member joins the third cutter member, and a fourth rectangle sideline parallel to the first sideline of rectangle at a distance from the center line equal to the distance between the first sideline of rectangle and the central line, the fourth lateral line of rectángul inte It connects the second and third rectangle side lines to form the rectangle within the side lines of the first, second, third and fourth rectangles.

It is important that the rectangle 66 be constructed according to the aforementioned method so that the total surface area d for the rectangle 66 can be established. When this is achieved, the area of the cutting surface of any blade configuration can be compared to the total surface area of the rectangle 66. The total surface area of any of the rectangles, formed by the above-mentioned method, does not have to be the same but must be close to the dimensions. For different knife configurations different blade thicknesses, the total surface area for rectangles 66 may be different when measured at the third or fourth decimal places.

The total surface area of the rectangle 6 can be calculated by multiplying its length times s width. One will then measure the area of the cutting surface d of the blade 14 which is present within the area d of the total surface of the rectangle 66 using the mathematical principles and the formulas. It should be noted that the area of the cutting surface of the blade 14 can be calculated using a Cad-Cam program. Cad-Cam programs are commercially available.

Referring to Table 1 given below, several calculations have been carried out by varying the thickness d of the first, second and third cutter members, 40, 44 and 4 respectively. For each calculation, all three cutter members 40, 44 and 46 have approximately the same thickness, either being .025 millimeters, .050 millimeters or .12 millimeters. To cut absorbent articles, for example, such as sanitary napkins and pant liners, it is not recommended to use a blade thickness greater than about .127 millimeters. The total surface area of the rectangle and the area of the cutting surface of the blade 14 square millimeters has also been calculated. One will see that area of the cutting surface of the blade 14 as a percent of the total surface area of the rectangle 66 varies depending on the thickness of the cutting members 40, 44 and 4 as well as the angle and location of the intersection of the first limb. cutter 40 in relation to the second and third cutter members, 44 and 46 respectively. It should also be noted that the thicknesses of the three cutting members 40, 44 and 46 have to be the same.

TABLE 1 Surface Area Surface Area Blade Area Thickness in Total Cutter as% of Dulced (mm) Rectangle (mra3) Blade (mm2) Rectangle .025 .07742 .016130 20. 83 .025 .07742 .01290 30. 77 .050 .08387 .02580 30. 77 .050 .08387 .03226 38 .46 * .127 .10323 .0645 62 .50 .127 .10323 .0645 68 .75 NOTE: 1 inch = to 25.4 mm. 1 square inch = 64.52 square millimeters.

Referring again to Figure 7, the area the cutting surface of the blade 40 represents 30.77% d total surface area of the rectangle 66. The 30.77% f obtained when each of the first second and third cutting members, 40, 44 and 46 respectively, had a thickness of approximately 0.25 millimeters. As the blade 14 becomes larger and thicker and by changing the angle at which the first member 40 intersects the second and third cutting members 44 and 46 respectively, the area of the cutting surface of the blade 14 within the total surface area of the rectangle 6 will change.

Referring to Figures 8 and 9, the first, second and third cutter members, 40, 44 and 4 respectively, also have a thickness of .025 millimeters but the first cutter member 40 intersects the second cutter member 44 at an off-center angle. The formation of rectangle 82 is identical to that described above for rectangle 6 shown in figure 7. In fact rectangle 82 has the corner points "E", "F" and "K" and lines 68, 70, 72 and 80 For the blade profile shown in Fig. 9, the area of the cutting surface of the blade 14 is 20.83% of the total surface area of a rectangle 82. The reason that the area d the cutting surface of the blade 14 is smaller in FIGURE 9 than in FIGURE 7, because the first cutter member 4 is offset from the second cutter member 44. This forms a non-symmetrical arrangement between the second third cutter members, 44 and 46 respectively. In this arrangement, less surface area of the second cutter member 44 is included in the calculation and therefore a lower ratio is obtained.

Similar calculations were made for the blade 14 when the thickness of the first second and third cutting members, 40, 44 and 46, respectively, increased to .05 millimeters. In this case, the area of the cutting surface d of the blade represented 30.77% of the total surface area of rectangle when the blade 14 was similar in appearance to that shown in Figure 6 and of 38.46% of the area of the total area of the rectangle when the blade 14 was similar in appearance to that shown in figure 8.

Referring now to Figures 10 and 11, s made similar calculations by varying the thickness of the first, second and third cutter members, 40 ', 44' and 46 ', respectively, so that they all had a thickness of .12 millimeters . In Figure 11 the area of the cutter surface of the blade 14 was calculated as being 62.5% of the total surface area of the rectangle 84.

The heavy duty blade and cutter method of the present invention employ a cutter blade thickness in the range of about 0.003 inches to about 0.005 inches.

Referring now to Figures 12 and 13, s did the calculations for the three cutter members 40 ', 44 and 46', respectively, when they each had a thickness of .127 millimeters, and the first cutter member 40 'was off-center relation to the second cutter member 44 '. The area of the cutting surface of the blade 14 was calculated as 68.75% of the total surface area of the rectangle 86. The calculations mentioned above are all listed in Table 1 given above.

It should be noted that the area of the cutting surface of the blade 14 can represent from about 20% to about 70% of the total surface area of the rectangle. More particularly, the area of the cutting surface of the blade 14 can represent from about 20% to about 40% of the total surface area of the rectangle.

It should be noted that the area of the cutting surface of the blade 14 can represent from about 20% to about 70% of the total surface area of the rectangle. More particularly, the area of the cutting surface of the blade 14 can represent from about 20% to about 40% of the total surface area of the rectangle.

It has been found that such a blade 14 is extremely useful for cutting absorbent products because the common edge 16 decreases the amount of trim waste that would normally be present between two adjacent blades but not butt. By reducing the amount of clipping waste, one can obtain an efficient operation using less raw material. The common edge 16 of the blade 14 is capable of cutting a part of the outer periphery of the two adjacent products with a simple cut and therefore can increase the production of multiple products.

Although the invention has been described in conjunction with several specific embodiments, it should be understood that many alternative modifications and variations will be apparent in light of the foregoing description. Therefore, this invention is intended to encompass all such alternatives, modifications and variations which fall within the scope of the invention. of the spirit and scope of the appended claims.

Claims (20)

R E I V I N D I C A C I O N S

1. A blade, comprising: a) a first linear cutter member having a first end; b) a second cutter member having a linear section and an arcuate section attached to said first end of said first cutter member; c) a third cutter member having a linear section and an arcuate section attached to said first end of said first cutter member and further joined to said arched section of said second cutter member; d) a non-symmetrical configuration formed by said arcuate sections of said second and third cutter members cooperating with said first cutter member and having an outer edge and a central line arcuately formed; e) a cutting edge on said first, second and third cutter members having a thickness of cutting edge knife in the range of about 0.00 inches to about 0.003 inches; and f) a cutting edge surface area in the range of about 20% to 40% of the total surface area of the rectangle drawn on said non-symmetric configuration formed by a first rectangle side line between each of one of the two corner points of rectangle located on said outer edges of said second and third cutter members, respectively, in a place where said respective arcuate section is attached to said linear section, a second lateral line of rectangle and a third rectangular line of rectangle perpendicular to said first side line d rectangle in each of said two corner points d rectangle and extending by a distance through a central line placed where said second cut member joins said third cutter member, and a fourth side line d rectangle is parallel to said first lateral line d rectangle at a distance from said center line equal to the di stancia between said first lateral line of rectangle and dich central line, said fourth lateral line of rectangular intersects said lateral lines of second third rectangle to form said rectangle within the lateral lines of rectangle first, second, third and fourth.

2. A blade as claimed in clause 1 characterized in that said blade is machined from the outer periphery of a rotating shaft and formed integrally on said shaft.

3. A blade as claimed in clause 2 characterized in that said cutting edge has a depth of cut in the range of about 1/8 of a inch to about 3/16 of an inch.

4. A blade as claimed in clause 3 characterized in that said cutting edge has a thickness in the range of about 0.0012 to 0.0018 inches.

5. A blade as claimed in clause 4 characterized in that said third arcuate section cutter member attached to said second cutter edge d cutter member forms a circular arc of about 18 degrees.

6. A blade as claimed in clause 5 characterized in that said blade is composed of tool steel.

7. A method for cutting a sanitary napkin from a fabric of absorbent material in layers, comprising: a) providing a first linear cut member having a first end; b) providing a second cutter member having a linear section and an arcuate section attached to said first end of said first cutter member; c) providing a third cutter member having a linear section and an arcuate section attached to said first end of said first cutter member and further attached to said arcuate section of said second cutter member; d) providing a non-symmetrical configuration formed by said arcuate sections of said second and third cutter members cooperating with said first cutter member and having an outer edge and an arcuately formed central line, -e) providing a cutter edge on said cutter members first, second and third having a cutter blade thickness in the range d about 0.001 inches to about 0.003 inches; Y f) providing a cutting edge surface area in the range of about 20% to 40% of the total surface area of the rectangle drawn on top of a non-symmetric configuration and formed by a first rectangle line between each of the two points of rectangle corner located on said outer edges of said second and third cutter members, respectively, in place where said respective arcuate section is joined said linear section, a second rectangle sideline a third rectangle lateral line perpendicular to the first lateral line of rectangle in each of said d corner rectangle points and extending by distance through a central line placed where second cutter member joins said third cutter member, and fourth rectangular sideline parallel to said first line lateral of rectangle at a distance from said centr line equal to the distance between said first line of rectangle said central line, said fourth rectangular line of intersecting said lateral lines of second third rectangle to form said rectangle within said lateral lines of rectangle first, second, third and fourth.

8. A method for cutting a sanitary napkin is a layer of absorbent material in layers as claimed in clause 7, characterized in that said cutting edge is machined from the outer periphery of a rotating shaft and formed integrally on said shaft.

9. A method for cutting a sanitary napkin from a fabric of absorbent material in layers as claimed in clause 8 characterized in that said cutting edge has a cutting depth in the range about 1/8 of an inch to about 3/16 of inch.

10. A method for cutting a sanitary towel of a fabric of absorbent material in layers as claimed in clause 9, characterized in that they also purchase placing said cutting edge at a proximity of from corresponding anvil to cut through only about 80% to 90 % of the thickness of said fabric of absorbent material layers.

11. A method for cutting a sanitary towel of a woven layer of absorbent material as claimed in clause 10, characterized in that it further comprises providing said cutting edge having a thickness in the range of about 0.0012 to 0.0018 inches.

12. A method for cutting a sanitary towel of a weave of layered absorbent material as claimed in clause 11 characterized in that said third arcuate section of cutter member attached to said second cutting edge cutter member forms a circular arc of about 100.degree. 180 degrees.

13. A method for cutting a sanitary towel of a woven layer of absorbent material as claimed in clause 12 characterized in that said cutting edge is composed of tool steel.

14. A method for cutting a sanitary towel of a woven layer of absorbent material as claimed in clause 13, characterized in that said fabric of absorbent material in layers is less than about 3/3 inches in thickness.

15. A method for cutting a sanitary towel of a weave of absorbent material in layers as claimed in clause 13 characterized in that said sanitary towel comprises a lining for panty.

16. A blade, comprising: a) a first cutter member having a first end; b) a second cutter member attached to said first end of said first cutter member, said second cutter member having an inner edge; Y c) a third cutter member attached to said first end of said first cutter member, said third cutter member having an inner edge joining said second cutter member having an inner edge to form a circular arc between said second and third cutter members said cutter members second and third are arranged in relation to each other to form an angle there from around 30 degrees to around 150 degrees, each of said second and third cutter members has an arched section which cooperates with said first cutter member to form a non-symmetrical configuration, each of said second and third cutter member having a linear section integrally joined to said arcuate section and said First, second and third cutter members have the same blade thickness, said blade thickness varies from about 0.001 inch to about 0.005 inch.

17. The blade as claimed in clause 16 characterized in that said first cutter and linear member.

18. The blade as claimed in clause 16 characterized in that said first cutter member n is linear.

19. The blade as claimed in clause 17 characterized in that each of said second and third cutter member has a linear section integrally joined to said respective arched section, and each arched section has an outer edge and a central line arcuately shaped, and when a rectangle is pulled around the point of intersection of said first second and third cutter members, the area of the cutting surface of said blade is between about 20% to about 40% of the total area of said rectangle, said rectangle formed by pulling a first line through dots, each of said points is located on a d the outer edges of said second third cutter members, respectively, in a place where said arched section is attached to said section linear, a second line a third line are then pulled perpendicularly to dich first l In places where said first line crosses said outer edges of said second and third cutter members, respectively, a fourth line is then pulled parallel to said first line so that it passes through a point where the center line of said second cutter member joins the center line of said third cutter member and a fifth line is drawn parallel to said fourth line and a distance of said fourth line which is equal to the distance between said first and fourth lines, said fifth line being drawn on the Same side of the first line as the fourth line, and said fifth line intersects said second and third lines to form said rectangle.

20. The blade as claimed in clause 19 characterized in that said first cut member said second cutter member and said third cut member have a thickness of about 0.003 inches. SUMMARY A knife apparatus and novel method are described for cutting a plurality of articles from a woven sheet of material. The blade can be formed in secured to the outer surface of a rotary die cutter. The blade includes a first cutter member having a first end, a second and a third cutter members attached to the first end of the first cut member. The second and third cutter members are arranged one in relation to another to form an arched section the intersect with the first cutter member to form a general non-symmetric configuration. A unique blade profile allows two articles arranged adjacent to be cut simultaneously from a sheet or fabric of material with a zero separation between at least a portion of the outer peripheries of the two articles.