JP2759846B2 - Article protection method and article protected by the method - Google Patents

Abstract

A filling material (10) for use in filling hollow spaces in packaging or the like comprising one or more pieces of flexible paper material (12). The paper material has a plurality of individual slits (14, 16) formed in parallel spaced rows extending transversely from one end of the paper material to the opposing end of the paper material. The slits in adjacent alternate rows are positioned adjacent the interval space (20) between adjacent slits in the adjacent parallel row of slits. The flexible paper material (12) is expandable by extending the opposing ends (22, 24) of the paper material which are parallel to the rows of slits whereby the slits form an array of openings, each opening being generally hexagonal in shape and of the same size. The length and width of the flexible filling paper material can be varied. The construction of the flexible paper filling material provides it to be easily stored in the non-expandable position and easily expanded for use in filling hollow spaces in packaging.

Description

Description: TECHNICAL FIELD The present invention relates to a dunnage or cushion material generally used as a packaging or packaging material, and more particularly to filling a hollow space of a shipping container for packaging. Or a new and improved dunnage material for packaging articles.

BACKGROUND ART Materials for filling hollow spaces in the packaging or packaging of articles for the purpose of protecting the articles during movement are conventionally known. However, to date, these materials
Neither is as effective as newsprint paper, or is a styrene foam or plastic hemispherical sheet (bubb
le) as ecologically unhealthy. The production of styrofoam and plastic hemispherical sheets creates toxic waste and creates waste disposal problems. While the recycling of these products is possible, storing them for the purpose of reuse is too bulky and generally not feasible for home occupants and some industries. Another drawback of existing packing materials is that they cannot be transported without stretching, resulting in transportation costs based on bulky bulk.

Although conventional contrivances have led to improvements in the intended field, none of the prior art has solved the problems associated with general transportation. Prior patents do not disclose any environmentally safe materials that can be packaged in fragile items.

The invention of the present application can satisfy the needs of the user,
1 shows an environmentally safe filling material made from recycled paper of various dimensions. Since the cushioning effect of the filled paper is achieved by stretching during use, transporting in an unstretched state is advantageous for transportation and storage.

DISCLOSURE OF THE INVENTION The present invention provides a new and improved packaging and packaging material for use in filling hollow spaces such as packaging and / or packaging of articles.

The expanded cushion material is at least one sheet of a substantially flexible non-woven fibrous material, preferably made of biodegradable cellulose fibers. Use 30 lb (13.6 kg) paper. Most preferably, at least about 70 pounds (31.7 kg) of recycled paper is used. Recycled paper that is stiffer than non-recycled paper and has an average fiber length that is substantially smaller than that of non-recycled paper is desirable. Since the grain orientation of the recycled paper is substantially inferior to that of the non-recycled paper, the orientation memory is smaller than that of the non-recycled paper and the tendency to return to the unstretched shape is low. Desirably, the thickness of the paper material is less than about 0.03 inches (0.76 mm), and the thickness may be on the order of about 0.02 inches (0.5 mm).

Each sheet, in its unstretched state, has a plurality of rows of parallelly spaced individual slits which are substantially straight, approximately one-half inch (12.7 mm) long, Extends laterally from one end to the other end. Each of the rows is provided with a spacing space between successive slits, the slits of adjacent rows are located adjacent to the spacing space, and the slits of one row substantially oppose the space of the next row. It is arranged as follows. Preferably, the slits are arranged in a consistent and repetitive pattern.

The flexible sheet stock is expanded before the article is wrapped in paper or during the wrapping process.
I can do it.

The sheets can be stretched by stretching both ends of each sheet parallel to the row of slits forming the row of openings. Each opening is generally similar in shape and size, and is preferably generally hexagonal. According to the preferred pattern of slits, a polygon having an even number of sides is formed, but a hexagon is most preferably formed. Desirably, the filler material has a stretched thickness of at least about 10 times the unstretched thickness of the sheet and is capable of being stretched to about 20 times the unstretched thickness of the sheet. The opening action greatly increases the effective thickness of the paper by bending the land portion between the slits, that is, the substantial portion, in a direction perpendicular to the paper surface. The expanded sheet is provided with an opening and a land, and at least most of the land is arranged on a plurality of parallel surfaces so that the surface of the expanded sheet is approximately 45 to 90 degrees.
It forms an angle of less than degrees (when fully extended), and this angle is preferably about 79 degrees.

The expanded cushion material has a minimum load carrying capacity of at least about 150 lb per square foot of stretch material.
Desirably, the load carrying capacity is at least about 250 lb per square foot. At least about 450l per square foot
b, the versatility of the application is increased, and
Optimum cushioning is achieved in typical applications by using a 2-3 layer expanded sheet.

Preferred load-bearing range is 250bl-200 per square foot
0 lb. At extremely high load bearing capacity, the expanded cushion material is too stiff to absorb shock effectively, causing wear rather than elasticity.

When the filling material is wrapped around the article, the lands of adjacent sheets in the sheets of each layer are overlapped and entangled with each other, resulting in a state of a plurality of entangled stretched sheets, which prevents shrinkage of the stretched sheets or At the very least.

The filling material can be stored as a stack of sheets. Alternatively, it is stored as a single sheet in a continuous roll. Since this roll can be formed of a plurality of sheet layers, at least one pair of sheets can be rewound together when rewound. The parallel rows of slits are parallel to the longitudinal direction of the continuous roll, thereby facilitating the winding of the sheet during manufacturing without stretching after the formation of the slits.

Desirably, the fibrous texture of the paper material is parallel to the longitudinal direction of the continuous roll, thereby providing maximum tear resistance because it is more difficult to tear across the fibrous texture than between adjacent fibers. is there.

If the rows of parallel slits are transverse to the longitudinal direction of the continuous roll, the sheet can be stretched in a direction that allows it to be unwound from the continuous roll, making handling convenient during the packaging process.

The packaging material can be returned to its original shape by applying a reverse contraction force to the edge of the paper material that is not parallel to the row of slits to reverse the opening action. The contraction force is applied at right angles to the force applied to stretch the sheet.
The paper material can be stored flat for future reuse.

BRIEF DESCRIPTION OF THE DRAWINGS The above objects and advantages of the present invention will become apparent from reading the specification with reference to the following drawings.

FIG. 1 is a top view of the slit sheet of the present invention, FIG. 2 is a perspective view of a stack of the slit sheets of FIG. 1, and FIG. 3 is a top view of the expanded slit sheet of FIG. FIG. 4 is a cross-sectional view of the container using the slit sheet of FIG. 1, FIG. 5 is a cross-sectional view of the container using the slit sheet of FIG. The figure is an enlarged fragmentary top view of the slit sheet, FIG. 7 is an enlarged fragmentary top view of the slit sheet of FIG. 6 partially open, and FIG. FIG. 9 is an enlarged fragmentary top view of the slit sheet of FIG. 9; FIG. 9 is an enlarged fragmentary top view of the slit sheet of FIG. 6 opened approximately 180 degrees; FIG. 10 is a projection of the present invention. FIG. 11 is a side view of the two cells obtained, and FIG. It is a side view of another embodiment of two cells that caused the load-in FIG. 12 unbound thickness 0.078 inch (unbound) Paper
FIG. 13 shows a load / deformation test of 0.078 inch thick non-bonded paper, FIG. 14 shows a load / deformation test of 0.078 inch thick non-bonded paper, and FIG. FIG. 16 shows a load / deformation test of a 0.078-inch bound paper, FIG. 16 shows a load / deformation test of a 0.078-inch thick bound paper, and FIG. 17 shows a load / deformation test of a 0.078-inch thick bound paper. FIG. 18 shows a load / deformation test of a 0.030 inch thick bonded plastic, FIG. 18 shows a load / deformation test of a 0.030 inch thick bonded plastic, and FIG. 20 shows a 0.080 inch thickness FIG. 21 shows a load / deformation test of a 0.080-inch thick bonded plastic, and FIG. 22 shows a load / deformation test of a 0.040-inch thick bonded plastic. FIG. 23 shows a load / deformation test of a 0.040 inch thick bonded plastic, and FIG. 24 shows the relationship between FIG. 15 and FIG.

In order to maintain clarity in this disclosure, the following definitions of certain terms are included. These definitions are in the second edition of G. Shortley and Dee Williams' Elements of Physics, published by Prentice Hall, Inc., Englewood, NJ (1955).
Year). (Elements of Physics, G. Shortley and
D. Williams, Second Edition, Prentice-Hall, In., 199
5.) Stress refers to the force that causes deformation. Strain relates to the amount of deformation.

Work is used in its technical definition. For a force to act on an object, for an object it is necessary to have a displacement having a component parallel to the direction in which the force acts.

Energy is a measure of an object's ability or function to do work. It is a scalar quantity and is measured in units similar to work. The energy possessed by the object as a result of the movement is called kinetic energy. The energy that an object has as a result of its position or shape is called potential energy. Speaking of an elastic body, it is called energy elastic potential energy. The elastic potential energy of the cushioning material is the amount of work the cushioning material can do in absorbing the energy of the article.

Hooke's Law-Within the elastic limit, the deformation of an object is directly proportional to the magnitude of the applied force. The stretch material of the present invention,
There is no direct relationship between the deformation and the magnitude of the applied force. As shown on page 182 of the "Element of Physics", the above relationship indicates a follow-up closer to the characteristic curve of rubber.

An elastic body refers to an elastic body whose volume or shape changes when a deformation force is applied, but returns to its original size or shape when the deformation force is stopped.

Elasticity refers to the force that makes an object work by its deformation.

The yield point is a point beyond the stress at which the strain is greatly increased with almost no increase in stress.

Paper strength is measured in burst strength, tear strength and tensile strength. Tear strength is important with respect to the ability of the paper to resist slit tearing during the stretching process. Paper tear resistance is TA
It is measured according to PPI-T-414-0m-88. In this method, after a tear is initiated using an Elementoff type tear tester, the force perpendicular to the plane of the paper required to tear a plurality of sheets through a specific distance is measured. When tearing a piece of paper, the tear resistance is measured directly. The tear resistance of the slit is greater in the direction crossing the fiber direction than in the fiber direction. This is because the fibers have less resistance to tearing apart than torn or torn. Long or highly oriented fibers exhibit high transverse tear strength, but exhibit a "memory" or tendency to return to the original state of the fiber when bent. Thus, although long-fiber virgin paper provides high tear resistance, it tends to return too much after the stretching process, i.e., exhibits memory.

Tension is the strength required to tear the paper and is always in the opposite direction to the tear strength. Tensile strength is TAPPI-T494 0
Measured according to m-88. 50 recycled kraft paper
%, 40% virgin paper gives a tear strength of 240 g fibrous or 120 g transverse strength. In the Murren test, it was 100% Murren. Thus, the burst pressure for 70 lb paper is 70 lb. The burst strength of recycled paper with post-consumer content is 50% or 60% Murren. In a 70 lb sample, the burst strength would be (0.6 × 70) and the grammage would be 112 g per square meter. 70
The tear strength of lb paper is 96 g in the longitudinal direction and 120 g in the transverse direction.
The tensile strength is 6.792 g / cm (38 lb / in) in the machine direction and 3.396 g / cm (91 lb / in) in the transverse direction. For use in the present invention, tear strength is very important as it overcomes the tendency of the slit to tear by stress. Once the paper of the present invention is stretched, the Mullen strength or tensile strength has no effect on the cushioning effect. However, paper stiffness affects performance. If the fiber structure is mainly oriented at right angles to the slit, the optimal tensile strength for the inclined land area,
There are advantages to providing tear resistance and stiffness.

Example As an example, an extensible sheet material was manufactured using a blend of 60% recycled kraft paper and 40% unused material. The tear strength was 240 lb in the fiber direction and 120 g in the transverse direction. The burst pressure of this paper was 70 g (7
0lb paper, 100% Murren). Typical burst strength of recycled paper with post-consumer content is 50-60%.

Example I Ordinary 70 lb kraft paper was fed to a slitting machine to hold each sheet on a flat table while simultaneously forming all slits. The properties of this paper are as follows.

Weight 70 lb (weight range 64 to 74) Thickness (caliper thickness) 7.6 mil (range 7.4 to 8.0 mil) Tensile strength-normal MD 50 lb / in (minimum 44 lb) (vertical) Tensile strength-normal CD 20 lb (Minimum 18lb) (Horizontal to MD direction) Humidity 5% Longitudinal (MD) tear strength 140g (Minimum 130g) Lateral (CD) tear strength 160g (Minimum 140g) Mullen strength 55psi (Minimum 50psi) Finish Calender Zero Roll Gap (0Nip) As manufactured, the paper is passed through a series of calender rolls or nips to flatten the top surface for printing. 0
The roll gap from 1 to 8 produces a bulky fibrous paper. Eight roll nips form a flat, stiff and hard surface paper. The larger the number of roll nips, the more the fibers are crushed and the lower the tear strength of the paper. In the present invention, it is preferable to use a material having zero roll gap, so that the fiber becomes bulky and strong. This is advantageous when the paper is unrolled by hand or without a dedicated machine, as described below. With dedicated machines, weaker paper is used, thereby increasing its stiffness, increasing overall yield and increasing finished product. The ability to utilize lighter weight paper is based on the fact that the machine spreads each cell smoothly and evenly, and the rollers needed to spread each cell reduce the force required to spread each cell. Once each cell is expanded, the various paper weights work well depending on their stiffness. However, recycled paper has the advantage that the shorter fibers are less stretchable and thus can be more easily spread. Obviously, the more precise the slitting of the paper, the easier it is to spread the paper. Recycling paper breaks fibers and reduces fiber orientation during regeneration. The fibers are crushed as a result of recycling or embossing, which in extreme cases results in the creation of softness such as tissue paper. Such softness causes minimal wear, but has little cushioning.

Almost completely recycled paper can be used if the paper texture (the direction of maximum strength) is opposite to the direction of the slit. If the grain is in the same direction as the slit, it is difficult to spread the paper, and the paper tends to tear before spreading. Although the strength of the paper seems to have to be in the direction of elongation, what is actually needed is sufficient strength at the axis of the slit to prevent tearing of the slit. As the paper is stretched, the various forces acting on the paper act tangentially on the slit and increase as the paper is stretched. Recycled paper is less elastic than fresh paper and tears before being fully spread. If the direction of the fiber pattern is not 90 degrees to the slit direction, a very weak recycled paper can be used because the hexagonal cell becomes very rigid once it is expanded.

One means of measuring the ability of an expanded cushion material to provide the required cushioning action is the deformability. That is, the amount of compression of the expanded sheet material under load. At least about 25% of its stretch thickness
Is desirable. Stated another way, the expanded cushion material can have a deformation capacity of at least about 1/20 inch per layer under a load of about 500 lb per square foot. In view of the load / deformation ratio, the expanded cushion material has the advantage of having a compression deformation ratio of at least 40 psf / 0.01 in for a deformation of at least 0.05 inches. Desirably, the expanded cushion material has an average compressive deformation ratio of at least 80 psf / 0.01 in during a deformation of at least 0.1 inch.

The slit paper 10 is shown in FIG. 1 as it appears from the machine. The flexible sheet 12 is preferably manufactured exclusively from recycled paper so that the fibers are oriented in the direction of arrow A. The flexible sheet 12 has its ear end 22
Slits 14 and 16 are provided which are parallel to 24 and are orthogonal to the fiber of the paper. The slits 14 and 16 are in a row and are separated from each other by a land 20. Spacing space 20
D has uniform dimensions and provides the necessary support to prevent the paper from tearing into strips when the paper is unrolled. Therefore, the spacing space 20D must be large enough to prevent tearing. The spacing between slits 14 and 16 must be large enough to prevent the paper from tearing.
The row of slits 14 and 16 is staggered,
It imparts elasticity to the paper when it is unrolled, and is described in further detail below. Both ends 26 and 18 of the flexible sheet 12
And the presence of the partial slits 14 and 16 in the slit paper 10
However, it is possible to cut the flexible sheet 12 into desired dimensions after the flexible sheet 12 is manufactured from roll paper. In its flat state, the sheet is in the first plane. When expanded, the expanded sheet becomes a cell as shown in FIG.
26 and land part 20 (including land area 20A and leg area 20B)
Is formed. Desirably, at least most of the area of the land portion 20 is in a plurality of parallel planes. The plane of the land area 20A forms an angle of at least about 45 degrees with the plane of the flat sheet.

The slitting operation for slitting the sheet material can take several forms. In one embodiment, a rectangular sheet is provided with a total number of slits in a single operation. A rectangular word is a square with all sides equal,
That is, it should be understood to include a square. When the sheet material is subjected to rotary cutting or slitting, the pressure required for the cutting action is substantially lower than that required for flatbed cutting, since virtually one or a few rows of slits are simultaneously opened. If the slit is oriented longitudinally, that is, parallel to the direction of travel of the sheet material in the rotary cutter, the pulling force does not cause premature stretching. Unlike prior art structures and systems, stretching that occurs simultaneously with slitting is undesirable. In this way, the sheet material has an effective thickness of about 1/20 of the thickness of the expanded sheet material. The compact and dense shape gives optimization of transportation and storage.

Placing the rows of slits 14 and 16 at right angles to the paper grain direction A is critical for optimum strength. Due to the structure of the paper, the majority of the fibers are directed in a single direction forming a fibrous grain where the strength of the paper is greatest. Arranging the rows of slits 14 and 16 at right angles to the grain direction A places the strength on the axis of the slits. As the paper is stretched, various forces acting on the paper reach the slits 14 and 16 tangentially and increase as the paper is stretched. Fiber A is slit 14
As it prevents 16 and tears from reaching the land part 20,
The slits 14 and 16 must pass completely through the paper. If the slits 14 and 16 are partially cut, the fibers will remain across the slits 14 and 16 and prevent full opening of the slits 14 and 16 and prevent the formation of a hexagon. The uncut fibers require more force to spread the cells 26 and transform the upward lift into a downward lift to deform the cells. The downward positioning of the lands 20 further inhibits tangling of the grid pattern when placing one sheet on top of another. This is the reason for the reverse tilt angle where the sheets are pushed away from each other instead of tangling.

FIG. 2 shows slit paper 10 cut and stacked for transport. Since the slit paper 10 is manufactured as a flat sheet, it can be shipped in large quantities in a relatively compact stacked state. For example, 0.015 inch thick paper is approximately 15 inches tall and weighs approximately 50 lbs and contains 771 sheets. The compact nature of this material makes it possible to transport the equivalent of other bulk transport materials in very small spaces.
The ratio of the thickness of the slit paper 10 in the as-shipped state to the thickness after expansion is approximately 20: 1. This results in significant savings in transportation and storage costs. The filling space created by the stretching of the slit sheet 10 is approximately 22 times that of the unstretched sheet.

Also, after its use, the slit sheet 10 is "flattened" substantially to its original shape and can be stored and reused several times. This not only saves the cost of purchasing new materials, but also a substantial savings in the time everyone is aware of the need.

FIG. 3 shows the slit sheet 10 in a stretched state. To extend the slit sheet 10, simply pull the ends 22 and 24 on both sides in the directions shown by arrows B and C.
The rows of slits 14 and 16 are widened by stretching slit sheet 10 to form a row of hexagonal cells 26. When the slit paper is stretched, the land 20 is lifted and
30, 32 and 34 occur to form two similar sides of each hexagonal cell and rotate upward and horizontally to produce a lifting padding effect. The angle of the projections 30, 32, and 34 is determined by the amount of the land portion 20 between the slits 14 and 16 and the distance between the slits 14 and 16. The greater the angle, the greater the support. The angle of the cell 26, by virtue of its flexing ability, can contact an object without the total wear of a pure vertical ridge. The angle created by the projections 30, 32, 34 also serves to secure the slit sheet 10 to itself. The lands 20 help maintain the "memory" of the paper, thereby creating a pulling action as the paper attempts to return to its original shape. The vertical ridge attempts to retain "memory" for a short time before returning to its initial position. Paper no longer provides a cushioning effect because the paper loosens on the article once it returns to its original position. The fastening action facilitates the tightening and the tightening with tape is optional. Since the slope of the land area is less than 90 degrees, the wear is much less than the wear encountered by a protective object placed on a rigid support at 90 degrees to its surface. Thus, the land area is capable of providing a resilient, non-abrasive support.

If the strength is used properly, the use of recycled paper can be a very robust packaging material as long as it spreads. If the fibers A are not provided at right angles to the rows of the slits 14 and 16, the recycled paper has low extensibility and is inevitable to tear before being spread. Once unfolded, the hexagonal cells can be rigid enough to compensate for the thinness, so that cycle paper with lower crush strength can be used. This stiffness can be changed by the number of calender rolls during manufacture.

One method of packing the object 42 using the slit sheet 10 is shown in FIG. The slit sheet 10 is stretched and disposed in a "crumbled" state within the container 48, filling approximately one quarter of the container 48. The object 42 is placed in a container 48, and another slit sheet
10 is stretched and collapsed to fill the space 40 around and above the object 42. The hexagonal cells 26 of the slit sheet 10 capture the air around the object 42 and further support the object. Projecting parts 30,32,
34 provides non-rigid support so that the object is not affected by external influences (recorded in G). When force is applied, the inner package of the present invention will not collapse and flatten, but will buckle slightly due to vibration and shock, thereby preventing the object 42 from hitting hard surfaces.

Another use of the slit sheet 10 is shown in FIG. A long slit sheet 10 is used, which is long enough to be wound around object 42 many times. The slit sheet 10 is stretched to cause the protruding portions 30, 32, 34 to form protective hexagonal cells 26. Slit sheet 10 is arrow B
And C, around the object 42, thereby causing the hexagonal cell 26 to continuously stretch to overlap the layer below. The protruding portions 30, 32, 34 provide cushioning and contain air. A sufficient number of sheets are used to fill the space 40 in the container 48. Projection part 30,3
The entanglement that occurs at 2,34 allows the next sheet to be wound and secured to the sheet without the need for tape.

The preferred state of extension is shown in FIGS. 6, 7, and 8. FIG. FIG. 6 shows the slits 14 and 16 that have not been expanded yet, and more clearly shows the ratio between the slits 14 and 16 and the land portion 20. The slit lengths 16L and 14L are maintained at the same length throughout the cutting process. The slit interval 36 between the slits 14 and 16 is maintained at the same distance as the row interval 38. The smaller the row spacing, the smaller and more angled the lands 20, resulting in more hexagons. Conversely, if the column interval 38 is increased, the land portion 20 is enlarged and the cell 26 is decreased. Since the angle is also adjusted by the size of the row interval 38, the smaller the interval, the duller the angle formed. Slit interval 36
Directly affects the ease of opening and the number of cells 26. FIG. 7 shows the slits 14 and 16 partially open. The cells 26 are narrow and the lands 20 are not fully warped. In FIG. 8, the slits 14 and 16 are sufficiently extended so that the land 20 is slightly less than 90% squared.

As the dimensions of the cell 26 increase, the quality of the cutout becomes more important. The larger the cell 26, the greater the deformation, as shown in FIG. 9, unless the land 20 is deformed to extend flat around the fibrous edges instead of forming a protruding hexagon. . The cells 26 are stretched to their maximum extent to form squares or rectangles instead of hexagons. Stretching to this extent provides little or no cushioning action by the land 20. The higher the desired height, the more vivid and more complete the cutout must be. To provide proper warping, the paper needs to move 90 degrees in the direction of stretching, and at the same time increase in length. As a result, when the slits 14 and 16 try to expand in the opposite directions, a large load is applied to each end, and as a result, the fiber mesh A of the paper is
And the necessity to arrange them at right angles to each other.

The ratio between the length of the slit and the land interval between the slits is
Affects the dimensions of the polygon formed during the stretching process. The higher the ratio of the slit length to the spacing length, the greater the maximum angle that can be formed between the plane of the sheet and the plane of the land area. The more uniform the shape and size of the formed polygonal opening area and the uniformity of the inclination angle of the land area with respect to the flat sheet, the greater the degree of entanglement of the land area. Entanglement of the land areas, i.e., the sheet layers closely overlap, i.e., nesting, reduces the effective thickness of the sheet. However, the net effect is still a dramatic increase in effective sheet thickness. For example, 1 /
In the case of 0.008 inch thick paper having a slit pattern of 2 "slits, 1/16" land and 1/8 "rows, approximately 1 inch thick
It is extensible to / 4 and has a net effective thickness of approximately 0.375 inches when properly stacked.

The longer the slit relative to the rigidity of the sheet material, the weaker the entanglement and cushioning effects due to the weakened expanded structure. 100% of unstretched length
The cell sizing that results in the maximum extension above results in the expanded structure becoming too weak. If the slit is too small, the expansion or extension will be very limited and the cushioning will be very limited. This does not mean that the dimensions are narrow and limited, but rather the dimensions must be selected in relation to the properties of the paper, for example the required stiffness and cushioning or energy absorption. The resistance to stretching increases with increasing dimensions of the land area. It should be understood that some resistance to spreading is desirable.
The object rests or contacts the edge of the sheet formed by the slope of the land area, which turns the periphery of the opening into upper and lower edges.

Unlike metal, paper does not flow under pressure. That is, the metal is ductile or ductile, and can create and stretch slits without necessarily creating land areas and lifting them up with respect to the plane of the metal sheet. In this regard, reference is made to U.S. Pat. No. 4,089,090 which discloses the formation of expanded sheet metal without the attendant sheet width reduction.

As described above, the dimensions of the slit can be changed to facilitate the opening process. 5/8 "slit, 3/1
In the case of a 6 ″ land × 3/16 ″ row, the number of hexagons is reduced, so that opening can be made very easily. Increase the hexagonal dimensions,
And when the number is reduced, the stretched thickness increases and a very vibrant packaging material is made. This dimensional restriction increases paper yield and provides almost the same protection as a 1/2 "slit. This dimensional restriction allows for the use of a large amount of waste from large consumers while maintaining the integrity of the packaged product. The 1/2 "slit, 1/16" land x 1/8 "row pattern can produce more packaging materials in the same volume, so that packaging materials with increased protection can be used. To manufacture. Thus, a 2 1/2 lb petal can be protected from a height of 30 inches and a 1/2 "slit pattern around the petal with only a 1/2" land.

FIGS. 10 and 11 are end views showing the slit sheet 10
3 shows the protrusion effect in more detail. The protrusion 600 is at an angle of approximately 30 degrees from the original plane. The protrusion 60 is
The row spacing 38 is wider than the protrusion 64 in FIG. The wider the row spacing 38, the more lands warp and the smaller the angle. The protrusions 64 in FIG. 11 have an angle of 45 degrees or more and are formed using a narrower row spacing 38. Increasing the angle increases the warpage and reduces the risk of closing the cell. The use of multiple layers prevents the cell from closing as it creates a neat overlapping action, reducing the importance of angle in general use.

When stretched, the paper produces semi-rigid peaks or lands. These ridges resemble springs in that, if they do not exceed their elastic limitations, they return to their original position when a force is applied and they are removed. The elasticity created by the resistance of the paper fibers slows down the acceleration of the force. The work performed by the intention of the semi-rigid ridge when a force is applied by the article is the elastic potential energy of the expanded material.

The charts in FIGS. 12 to 17 show the load applied to the expanded sheet by the compression plate, plotted against the change in thickness of the expanded material when a load is applied.
The compression plate applies a force across the surface of the entire expanded sheet. The load shown in the chart is independent of the dimensions of the material to which the load is applied. Table II herein shows the conversion of applied load to loads in pounds per square foot. The test results presented here have been converted from total load per sheet to pounds per square foot to provide a means of comparison between sheets of different sizes. Table I
The first column is the applied load, the second column defines pounds per square foot of unexpanded material, and the third column defines pounds per square foot of expanded material. As is evident from Table I, the load capacity required to protect an item can be determined by the number of square feet of expanded or unexpanded material. The test was performed using approximately 19.25 inch x 37.25 inch sheets. The sheet length includes approximately 1.25 inches of uncut material, so the slit area is slightly less than 20 inches by 3 feet. The sheet is stretched to a length of 4 feet, creating an expanded surface area of about 5.5 feet versus about 5 square feet before stretching. Ordinary stretching increases the overall length by about 1 / 3in, while the decrease in width increases the square foot by only about 10%. The sheet was extendable about 60 inches further, but the maximum extension test was not performed. A unique feature of the present invention is the result of the cushioning effect achieved with a small extension of only 10% of the surface area. This increase in surface area is accompanied by an increase in thickness. At least about 10 for dramatic cushioning
This is a double increase in thickness. In the test, the sheet was pre-loaded until stabilization was achieved.

In analyzing the significance of the cushioning data, it should be understood that concrete blocks have a high load capacity but no ability to cushion the impact, ie have only minimal elasticity. To mitigate the impact,
Since a sudden stop is damaging, the object to be protected must gradually absorb its momentum with the elasticity of the cushioning material. Therefore, significant and progressive deceleration of the object must occur due to the elasticity of the cushioning material's strain resistance. The greater the amount of work expended to continuously absorb shock, the greater the effectiveness of the cushioning effect. The work spent is directly related to the elasticity of the cushioning material. The lightweight paper of U.S. Pat. No. 4,832,228 has little resilient potential energy due to the weakness of the paper used in the invention of this patent of less than 30 lb. Note that paper weight is pounds of paper per 1000 square feet before stretching. With a slit pattern of this material, the unstretched length of 100
Stretching by more than% is possible. This material can only absorb a small amount of energy during the deceleration of the protected article, until it encounters the stiffness of the adhesive material, at which point the deceleration becomes excessive. In addition, this material is used in an unentangled manner and is dependent on adhesive or structural strength. The presence of a rigid bond is at odds with the requirements of the cushioning material. Thus, it is clear that this material cannot be used as a cushioning material. In addition, the material collapses under small forces and cannot protect the article against repeated impacts during transport.

The expanded paper of the present invention deforms first, thereby absorbing the impact. This is illustrated in FIG.
The diagram in this figure shows the deformation of the packing material using a load of 4100 lb. The paper absorbs shocks gradually as the load applies downward pressure until the elastic limit is reached at point A. When a stress greater than point A is reached, the packing material has reached its elastic limit and the deforming force is removed so that it can no longer reproduce its original shape. When the force reaches the elastic limit, the material deforms. As the stress increases beyond the elastic limit, the yield point is reached and the fiber breaks. However, since the elastic limit and the yield point are so closely related that it is difficult to distinguish them, both points will be referred to below as the elastic limit. The additional force acts to collapse the structure, the paper resets itself at point B and provides some additional cushioning until point C is reached, and at point C the load increases. Little or no further compression occurs. Typically, once load deformation point A is reached, any subsequent absorption is largely too rigid to provide the necessary cushioning. Although additional support or cushioning occurs at reset point B, this factor has been discounted in the tests described below. As noted above, beyond the elastic limit of the material, the paper loses its ability to provide additional cushioning.

When utilized in multiple layers, each layer under load closely overlaps one another, providing an additional benefit and a greater distribution of impact forces or energy absorption. Because the layers overlap tightly, there tends to be a synergistic effect on the absorption properties of each layer. In a multi-layer system, the cushioning of curved areas AB may be of considerable value, and each layer may have a different and independently modified load / deformation point. Therefore,
The use of multiple layers provides maximum cushioning.

From the perspective of impact power dissipation, the benefits of the expanded paper design are even more recognizable. The strand network, which is constantly stretching in the paper, absorbs and dissipates the energy of the article whose movement is slowing down. Paper is made up of a large number of fibers that are not aligned with each other and are equivalent to nonwovens. Upon impact, the misaligned fibers entangle the object with more fibers and distribute the energy along the fiber axis toward the intersection where the energy is dissipated. The binder in the fiber prevents the shock wave from pushing the fiber aside, resulting in higher translation efficiency. Ideally, the tissue should dissipate rather than block the impact energy. Fiber friction is
It transfers the forces generated along the fibers and helps absorb energy. When used in multiple layers, a wide range of three-dimensional effects is achieved when energy is dissipated from layer to layer simultaneously in a pattern similar to the ripple effect of pebbles falling into water. The presence of wave action is recognized in each layer. The plastic sheets under test shown in FIGS. 18-23 are relatively inelastic and do not have sufficient elasticity to absorb a significant degree of impact. In essence, thin plastic films failed to meet the minimum load-bearing limits. Restated in technical terms, the elastic limit and elastic potential energy of the plastic film were insufficient for this material to have utility as a cushioning material. In particular, a load bearing capacity of less than 100 lbs per square foot (psf) is insufficient to provide the minimum required results. While the use of multiple layers offsets or mitigates the problems encountered with low load-bearing capacity, it requires an infeasible number of layers at this level,
Therefore, the usefulness of the expanded plastic material as a cushion material has been completely denied. Therefore, expanded plastic sheets of the type disclosed in U.S. Pat. No. 3,958,751 are unsuitable for functioning as packaging or packing material to mitigate the impact of articles in transit. At the other extreme, the reinforcing expanded sheet material of US Pat. No. 4,259,358 is much too rigid to function as a cushioning material.
The material disclosed in U.S. Pat. No. 4,259,358 exhibits little elasticity and thus has minimal elastic potential energy to mitigate the impact of an item. As used herein, the term cushioning material is consistent with the term used in U.S. Pat.No. 4,937,131, the disclosure of which is incorporated herein as though fully set forth herein. The purpose is to provide a background and terminology definition for the requirements of cushioning material or cushioning dunnage used as packaging or packaging material.

Prior art, such as the term dunnage as used in U.S. Pat.No. 4,937,131 and the patents cited herein, and the term cushioning material as used herein, protect articles in transit. A material that has sufficient shock absorption capacity. Essentially, the cushioning material must be capable of absorbing the energy of the impact and thereby avoiding damage to the article. The energy of impact is typically expressed as elastic potential energy. Materials that must be used in excessive thickness to provide some cushioning due to low load-carrying capacity, such as U.S. Pat.
The materials disclosed in 2,228 and 3,958,751 are not included in the term cushioning material. In addition, these late materials have very small elastic limits and cannot be used to absorb the repetitive shocks required to protect articles in transit. For example, if a 64 cubic foot box is filled with a material to protect a 2 inch diameter, 1 foot long, 1 lb item, this material is not included in the term dunnage or cushioning material.

At a minimum load-bearing capacity of 150 lb per square foot, multilayers should usually produce the minimum required results. If lightweight objects are packaged or minimal handling problems are anticipated, at least two or three layers of expanded sheet material will be used.

At 250 lb / psf, ordinary fragile objects can be protected with a reasonable number of expanded sheets. Typically, at this minimum number of layers, at least three layers are required for a fragile object.

At a load capacity of about 300 lb / psf, there is an increase in adaptability. That is, the 300 lb / psf level has significant general fitness.

At a load carrying capacity of about 400 lb / psf, universal adaptability for virtually all purposes is achieved, especially due to the synergistic effect achieved with the use of multiple layers.

Another variable that affects the achievable effect is:
The thickness of the expanded paper. A larger stretch or expanded thickness per sheet increases elasticity,
This increases the resistance to forces and raises the bulk elastic limit. The use of multiple layers to achieve the required thickness is desirable because of the nesting and bonding interactions between adjacent layers and the improved distribution of impact forces between closely overlapping layers. The upper limit is not strictly critical; more stiffness is naturally counterproductive. 2000lb / psf per layer
A load capacity of greater than is indicative of a rigid material that is typically low in elasticity and excessively abrasive. In a preferred embodiment,
The load carrying capacity is in the range of 500-1500psf to give the optimal elasticity. The use of multiple layers increases the amount of emissions per lb obtained from the cushion system. Furthermore, a greater effective load bearing capacity can be achieved with the considerable amount of movement obtained at high loads.

Another way to evaluate the effectiveness of cushioning involves the slope of the curve of the line plotted against movement.
If the curve is too steep, minimal shock absorption occurs because the material exhibits little elasticity. Load capacity is the maximum load that the expanded sheet can support before the gradient becomes too severe. In the following tests, the load capacity is
It is shown as the maximum load that can be extinguished before the elastic limit is reached.

Stated another way, an excessive gradient is a gradient that exhibits acne and deceleration so as to provide insufficient shock absorption. An excessively shallow gradient indicates a material that has too little resilience and little or no resistance to the applied force. To overcome this lack of elasticity or excessive elasticity, the material must be of excessive thickness to provide effective absorption of impact forces between the object and the expanded material. Load capacity in the range of about 250 to about 1000 lb psf is sufficient for expanded sheets of a reasonable number of layers, typically 2-4
Must be compatible with the use of expanded sheets of layers.

In terms of material movement, the expanded sheet must have a total deformability of at least about 25% of its expanded thickness. Deformation is at least about 500psf
It is preferably at least about 1/20 inch under a load of.
Deformation of at least 1/20 inch under loads of at least about 200 psf gives extremely effective results.

A load capacity of over 3000 psf expands the range of useful applications for expanded seat cushion materials.

As shown in the chart of FIG. 15, under a load of about 5125 lb.
Primary deformation occurs over a 0.180 inch compression distance. 5125l
At load b, the sheet collapses sharply, then about 0.0
Compression resumed progressively over a 5-inch distance. As mentioned above, the second stage of compression is the load on compression per inch.
When expressed in psf, it tends to be overrun and therefore has not been taken into account in the material evaluations described herein. The first stage of compression is defined as the area where significant load bearing is exhibited.

The compression test was performed on the following five types of packing cushion materials. Quantity Type Thickness Mounting means 5 Paper 0.078 Unbound 5 Paper 0.078 Bond 4 Plastic 0.030 Bond 5 Plastic 0.080 Bond 5 Plastic 0.040 Bond test Was performed using the following data.

Test preparation temperature + 23 ± -3 ° C Test preparation relative humidity 50 ± -5% Test preparation period 24 hours (minimum) Applicable specifications ASTM D642-90 Test machine Fixed plate Load direction Direction of top to bottom Machine speed 0.5 inch / minute Test data recorded Load deflection at yield strength (lb) (inch) The test reading is the total pounds of compressive force under the platen. The total number of square feet of an extensible sheet changes as the sheet is extended to its maximum extension length. However, for the scope of the present invention, between 1 psf and 900 psf
The 0% difference is not significant. Thus, a comparison of the load carrying capacity between two sheets is meaningful even if one is fully stretched and the other is partially stretched.

 A summary of the test results is shown in Table I below.

Tests 2, 3, 5, 7, 10, 11, 14, 15, 19, 20, and 23 are the first, respectively.
2 to 22 are included. All results for all test numbers were identified as above to avoid using an excessive number of drawings. For test numbers 11 to 24, two sets of numbers are included in the yield strength. The lower value indicates the point at which the material is crushed, and the higher value indicates the maximum load.

FIGS. 12-14 show the results of tests performed on 0.078 inch thick unbonded paper. In FIG. 12, elastic limit A is achieved at a weight of 2975 lb with a displacement of 0.105 inches; in FIG. 13, elastic limit A is achieved at 3265 lb with a displacement of 0.190 inches. In FIG. 14, the elastic limit with 0.130 inch displacement is 2062 lb. Unbonded paper samples showed a tendency to return to their previous unstretched state upon completion of compression.

FIGS. 15-17 show tests performed on 0.078 inch bonded paper. In FIG. 15, the elastic limit A is reached with a weight of 5125 lb with a displacement of 0.18 inches;
The elastic limit is reached at 4100 lb with 0.190 inch displacement in the figure; 2612 lb with 0.173 inch displacement is the elastic limit in FIG. A sample of the bonded paper showed evidence of deformation upon completion of the compression test.

18 and 19 were tested on a 0.030 inch thick bonded plastic. In FIG. 18, the elastic limit point A was reached at a weight of 58 lb with a displacement of 0.170 inch, and in FIG. 19, the elastic limit point A was reached at a displacement of 0.160 inch and 58 lb.

20 and 21 were tested on a 0.080 inch thick bonded plastic. In FIG. 20, the elastic limit point A is reached with a displacement of 0.140 inches and a weight of 57 lbs.
In the figure, the elastic limit point A is reached at a displacement of 0.260 inches and at 58 lb.

FIGS. 22 and 23 were tested on a 0.040 inch thick bonded plastic. In FIG. 22, the elastic limit point A was reached at a displacement of 0.085 inches with a weight of 55 lb, and in FIG. 23 the elastic limit point A was reached at a displacement of 0.140 inches with a weight of 63 lb.

The charts of FIGS. 12 to 23 show curves similar to those produced by rubber. The results for many materials in Hooke's law do not apply to slit materials in that there is no linear relationship between elastic extension and applied force.
This reduction in elasticity must therefore be responded to by the material used. As shown, the plastic has little elasticity or resistance to applied pressure. The paper of the present invention responds to the reduction in elasticity and slows down the deceleration of the object by the resistance of the material.

FIG. 24 shows the relationship between FIG. 15 and FIG. here,
It clearly shows that the cushioning effect of the plastic of line C is not as good as the cushioning effect of line D of the present invention.

The following table shows the correlation between the total pounds of load and the load per square foot of stretched material versus the load per square foot of unstretched material.

Commercially, articles can be packaged in the following order. The sheet material is unwound from a continuous roll of material as it winds and surrounds the object. Next, the sheet material is cut or torn from the roll to complete the wrapping operation. In another embodiment, the material is fed from that roll to a second roll rotating at a speed greater than the peripheral speed of the first roll, and the sheet material is stretched as it is unwound. This mechanism allows the sheet material to be stretched to its highest condition, in which the hexagon is stretched into a rectangular shape. In the case of a substantially cylindrical object, such as a beverage bottle, the sheet material stretches beyond the length of the bottle and does not outline the top and bottom of the bottle, thereby completely enclosing the article.

The sheet material is manufactured utilizing a modified rotary cutter in combination with a conventional unwind and rewind device. The rotary cutter uses two steel cylinders, the upper cylinder containing a flywheel containing the cutting edge.
Modifications to the wooden die include a knife mounted in a slit pre-cut into the wood. A series of threaded holes are machined in the upper cylinder to accommodate machined screws to facilitate the addition of an improved wooden die and to facilitate replacement of damaged knives. . The cylinder is fitted with a mold entry mechanism using screws that hold the cutting knife in place. The lower cylinder has been improved with the addition of a flexible surface called a bracket. This bracket allows the knife of the upper cylinder to penetrate the paper and penetrate the surface of the bracket. This creates cuts in the paper and eliminates the cost of each cylinder perfectly matching uniform roundness and pressure.

The unwinding and rewinding device makes it possible to use roll paper directly from a paper machine in a continuous process. This unwinding keeps the paper roll constant tension as the diameter of the roll decreases. An aligned skid path is used on each side of the rotary punch to hold the paper in a flat path. The rewinding machine utilizes the tension to appropriately rewind the finished product or to bypass the sheeter to cut the roll material to a desired length.

[Industrial Application Field] The filler sheet of the present invention can be formed into any desired and appropriate dimensions according to the space to be filled with the packaging material. Is merely an example in terms of size and thickness, which does not limit the scope of the invention.

 ────────────────────────────────────────────────── ─── Continuation of the front page (31) Priority claim number 962944 (32) Priority date October 19, 1992 (33) Priority claiming country United States (US) Preliminary examination (56) References US Patent 4921118 (US U.S. Pat. No. 2,656,291 (US, A)

Claims (11)

(57) [Claims] 1. A method for protecting an article by wrapping with an expanded sheet material to reduce impact and protecting the article, wherein the expanded sheet material is formed with a plurality of slits and spaced from one end to the other end. It has parallel rows of laterally extending slit patterns, each row having a spacing space between successive slits, wherein said slits in each row are spaced between successive slits in adjacent parallel slit rows. Stretching at least one sheet of sheet material, which is located adjacent to the space and comprising extensible sheet material, stretches the sheet material to at least 130% of its unstretched length; Form a row of hexagonal openings having generally similar shapes and dimensions in a consistent and uniform repeating pattern demarcated with the land area at least from its unextended position. Rotating by an angle of less than 45 degrees to less than 90 degrees; wrapping the at least one stretched sheet material around an article and wrapping the land area of a continuous layer of sheet material to entangle. And placing the packaged article in a package. 2. The method of claim 1 wherein said sheet material is paper and the paper is stretched to at least ten times its unstretched thickness prior to packaging the article. 3. The method of claim 1 wherein the tensile strength perpendicular to each slit of the sheet material is at least about 40 pounds. 4. The method of claim 1, wherein at least one of the sheet materials comprises a plurality of layers that have been stretched and interlocked. 5. The method of claim 1, wherein said sheet material is in the form of a continuous roll, comprising the step of unwinding a predetermined length of unstretched sheet material before stretching said sheet material. 6. The method according to claim 5, wherein the slit is formed in parallel with the winding direction of the roll. 7. The method according to claim 5, wherein said slit is formed perpendicular to the winding direction of the roll. 8. A sheet material comprising at least one flexible sheet material, wherein said sheet material has a plurality of slits formed therein.
It has parallel rows of slit patterns extending laterally from one end to the other at intervals, each of the rows having a spacing space between successive slits, wherein the slits in each row are adjacent parallel slits. Positioned adjacent to the spacing space between successive slits in the row, extending to at least 130% of its unstretched length in a direction transverse to the parallel row of slits, and forming a boundary between the land area and the leg area. A row of hexagonal openings having generally similar shapes and dimensions is formed in a defined and consistent uniform repeating pattern, wherein the land area is at least from its unextended position.
An article wrapped and protected in said sheet material stretched to be rotated through an angle of between 45 degrees and less than 90 degrees. 9. An article according to claim 8, wherein said sheet material is paper stretched to a thickness of at least 10 times its unstretched thickness. 10. The article of claim 8 wherein said land area is rotated from its unextended position to a 70 degree angle in a fully extended state. 11. The angle of the land area in the fully extended state is:
9. The article of claim 8, wherein the angle is approximately equal to the angle made by the slit of about 13 mm, the non-slit area of about 5 mm and the inter-row spacing of about 3 mm.