WO1991017932A1

WO1991017932A1 - Biodegradable cushioned packaging composition

Info

Publication number: WO1991017932A1
Application number: PCT/US1991/003519
Authority: WO
Inventors: Roger J. Baker; Ben-Zion Ptashnik
Original assignee: Earthright Packaging Products, Inc.
Priority date: 1990-05-22
Filing date: 1991-05-20
Publication date: 1991-11-28
Also published as: AU7984691A; EP0528960A4; EP0528960A1

Abstract

A cushioned packaging element (87) formed of biodegradable cellulose fiber material formed into shapes to maximize volume to weight ratio and configured to resist plastic deformation on shock impact and preclude crushing.

Description

BIODEGRADABLE CUSHIONED PACKAGING COMPOSITION BACKGROUND OF THE INVENTION The present invention relates to cushioned packaging material of the type which is used to cushion fragile articles in transit and more particularly relates to such a cushioned packaging composition which is biodegradable.

Heretofore cushioned packaging materials have been made of a variety of plastic compositions particularly lightweight blown styrene foam commonly know as "peanuts". These peanuts are lightweight blown styrene foam in various assorted shapes and are placed in boxes around articles which are to be cushioned from shock in shipping. While such styrene peanuts are acceptable from the standpoint of being lightweight and generally effective to provide a cushioned packaging material such styrene products have a significant drawback in that the styrene is not biodegradable resulting in problems in its safe disposition once it has accomplished its intended purpose of providing a cushioned package.

Another type of cushioned packaging material is formed of polyethylene sheets bonded together with air spaces or air bubbles formed between the sheets with the "bubble pack" used as a blanket wrapped about the article to be cushioned in a package. Still another type of cushioned packaging is the use of polyisocyanate foam which is typically foamed in situ to form a cushioned package which encapsulates an article to be packaged within its intended shipping container.

With the growing concern for the environment gaining greater momentum it has been recognized that disposition of unwanted materials which are not biodegradable in landfills is undesirable. Greater emphasis has now been placed on developing and utilizing materials which have no long term deleterious impact on the environment. Specifically, greater use of many types of plastic materials such as polyethylene commonly used in bags and packaging material, polyisocyanate and styrofoam have been criticized by those concerned with the impact that such products have on the environment when they end up a refuse. These materials cannot be burned because of the noxious fumes given off and must be disposed of in land fills. Because these materials do not biodegrade they have long term serious deleterious effects on the environment and do not lend themselves to ecologically safe disposition. OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide an ecologically safe biodegradable packaging composition which is effective in providing a cushioned packaging product while maintaining the ability for safe disposition by being biodegradable.

A still further object of the present invention is to provide a biodegradable and ecologically safe cushioned packaging material which can be formed into a number of effective shapes and forms to provide a wide variety of packaging functions.

SUMMARY OF THE INVENTION According to a preferred embodiment of the present invention a cellulose fiber material, such as one obtained from reprocessing of cellulose based products, such as newspapers and other paper products obtained from wood pulp, is shredded into a convenient size and mixed into an aqueous solution to form a past-like slurry. A mold of the desired shape for the cushioned packaging element is passed through the slurry and water is extracted from the mold form under vacuum pressure. When the water is partially extracted a mating mold form is brought into contact to complete the desired formation, the completed mold is extracted by a vacuum sucking and the product is dried. Preferred shapes for the cushioned packaging element are selected so as to provide a sufficient volume while retaining a relatively thin wall yet still provide a resiliency to counteract shock impact without crushing of the element to maintain the article in a completely cushioned environment throughout its intended transit.

These and other objects of the present invention will be more readily apparent after consideration of the following specification in conjunction with the accompanying drawings.

A BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic representation of a preferred method of manufacturing the cushioned packaging material of the present invention;

Figure 2 is a sectional view taken on line 2-2 of Figure 1;

Figure 3 is an enlarged detail of one aspect of the apparatus used in conjunction with the manufacture of the cushioned packaging material of the present invention;

Figure 4 is a top plan view showing one preferred form of the cushioned packaging material of the present invention;

Figure 5 is a sectional view taken on line 5-5 of Figure 4;

Figure 6 is a partial sectional view of another preferred form of the cushioned packaging material of the present invention;

Figure 7 is a top plan view of another preferred embodiment of the present invention;

Figure 8 is a sectional view of the embodiment shown in Figure 7; Figures 9 and 10 are views similar to Figures 7 and 8 showing still another embodiment of the present invention;

Figures 11 and 12 are views similar to Figures 7 and 8 showing still another embodiment of the present invention; and Figures 13 and 14 are views similar to Figures

7 and 8 showing still another embodiment of the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION

With reference now to the drawings and particularly Figures l through 3, there is shown schematically an apparatus and process to form the cushioned packaging element of the present invention. A tank 10 is provided within which is disposed a slurry formed of a relatively finely chopped cellulose fiber material which may be recycled newspapers and other paper products. The cellulose material is preferably newsprint, which may be recycled newspapers, corrugated cardboard or molded wood fiber products and mixtures thereof. The important aspect being all are obtained from refined wood products. The cellulose fiber is finely chopped, for example to a size of about one- sixteenth of an inch. The finely chopped cellulose material is mixed with water in a ratio of 97% water to 3% chopped cellulose material to form the slurry and is continuously agitated so that the slurry is maintained in a paste-like consistency.

Sufficient water is added to create a somewhat dense slurry having a paste-like consistency while agitated. The important criteria is that the slurry has enough body and consistency to lend itself to disposition in, and adherence on, an appropriately shaped mold form. A plurality of mold forms 12 preferably carried on the periphery of a rotating drum 14 are provided and as the drum rotates the lowermost segment of mold forms 12 are brought into contact with the slurry in tank 10. A vacuum is impressed to draw the slurry into the mold forms 16 and the slurry, because of its past-like consistency, adheres on the surfaces of female molds 16 of the desired shape in mold form 12. Preferably, female mold forms 16 are formed of a screening material, for example a screen having a 60/40 mesh or 60/54. As drum 14 rotates a slight vacuum from the interior of the drum partially extracts the water from the cellulose fiber slurry to allow the slurry to achieve a more viscous consistency as water is extracted. As the female mold forms 16 reach the uppermost position, as shown at 18 in Figure 1, a complementary shaped male mold form 20 carried on a reciprocating ram 22 is brought into close adjacent contact. Movement of the male mold form into close adjacent contact achieves a twofold purpose, the first being to complete the formation of the shape of the article being molded by compressing the soft and somewhat drier and more viscous slurry and establish the thickness of the cushioned packaging element. In addition because this step involves a compacting of the soft slurry additional water is dispelled through the screen. Making the resultant product even more viscous and shape retentive. It has been found that to achieve, in the end product, a form which has the desired strength characteristics that a thickness in the range of .015 to .025 and preferably of about .020 inches is satisfactory. Further rotation of the drum 14 brings the formed elements to the horizontal position, indicated at 24, where an extracting member 26 which includes complementary male mold forms 28 is reciprocated from a first retracted position, shown in Figure 1, to a second engaging position with the complementary male mold forms 29 resting within the relatively dry mold forms in the female mold forms 16. Extraction member 26 includes provision to impress a vacuum through air passage 28 and plenum 30. In addition positive air pressure from drum 14 is also applied at this juncture. When a vacuum and the positive air pressure are impressed the molded forms are extracted from the mold form 16 and, as extraction member 26 reciprocates to its retracted position, the completed molded elements are removed from the female mold forms and deposited on a take away conveyor (not shown) and are further dried in any appropriate manner to form the resilient cushioned packaging elements which are then utilized in forming a cushioned package to protect fragile articles in transit.

With reference now to Figures 5 through 16, there are shown preferred embodiments for the shapes of the biodegradable packaging elements.

An important consideration in the specific shapes of all the preferred embodiments of the present invention is to provide a shape which has a relatively large volume of occupancy, with a thin wall for weight saving considerations while at the same time providing a shape which can absorb shock in transit without crushing or losing its defined shape. Preferably, configurations are selected to achieve a high volume to weight ratio so as not to significantly increase the weight of packages using the cushioned packaging element. It has been found that the preferred cellulose fiber material when formed in the preferred shapes with a wall thickness of .020 inches provides a material which exhibits a degree of resiliency and ability to elastically deform under acceptable shock loads. In its dried form, the cellulose fiber material is not completely rigid but is readily deformable upon being compressed. Thus, the material itself exhibits a shock absorbing capability which acts to dampen any sharp impacts and dissipate the energy without transmitting the full force of the shock therethrough. The material is rigid enough to maintain the desired shape. In addition, the preferred shapes cooperate with the properties of the preferred cellulose fiber material to create individual cushioned packaging elements which can resist significant load forces without plastically deforming and losing any significant volumetric retention capabilities.

This is important because the volume of space within a container occupied by the cushioned packaging elements should not be readily reduced by crushing so that any article encased therein is continuously constrained against movement within its shipping container. If the space in a package occupied by cushioning material is reduced, because the packaging material is crushed due to incident shock, the article to be shipped will be able to move about in the container subjecting it to impact and shock which may cause damage. Accordingly, forms without sharp corners or points are most acceptable as forces which are applied to such rounded shapes are dissipated more uniformly as hoop stresses without stress concentration at sharp or pointed edges.

Figures 4 and 5 show one preferred shape for a cushioned packaging material utilizing biodegradable cellulose fiber in sheet form. In this preferred embodiment a series of domed protuberances 40 are disposed in relatively closely spaced relationship and interconnected by a thin wall sheet 42 at the bases to provide a continuous sheet of domed cushioned elements so that the sheet can fold along a line between protuberances 40 so as to be wrapped about an article to be cushioned within a package.

Reference is now made to Figure 6 for another preferred embodiment of the shape for a cushioned packaging element. In this embodiment, which may be circular or oval in plan, the element 43 is formed with a peripheral flange 44 and an upwardly extending partially domed wall 46 having a slight draft angle from the vertical for ease of molding and extraction from the mold. Wall 46 leads into a radius segment 48 to a partial vertical wall 50 and terminates in an interconnecting wall segment 52. Flange 44 beneficially provide a degree of stability to the shaped element 43 as well as providing the desired effect of spacing adjacent elements 43 further apart when confined in a package to increase the volume of space occupied by the elements and, thus, decreasing weight. The construction shown in figure 6 provides a flexible resistance to crushing and permits a hinging action at interconnecting wall 52 to allow for the absorption of shock by providing the ability to resiliently bend along hinge line 52 without crushing. In addition, the circular or oval shape permits the absorption of shock by flexible deformation much like a spring action, when force is applied as indicated by the arrows marked F. Because of this flexibility the element 43 resiliently deforms under load and springs back to its initial shape after the load is removed.

Figures 7 and 8 show still another preferred embodiment of the cushioned packaging element of the present invention. In this embodiment, where the element 53 is preferably oval in plan, an outer flange 54 is provided leading into a radius section 56 and a tapered upstanding wall 58 to a radius top 60 and a short lateral wall 62 leaving an oval opening 64 in top wall 62. This embodiment maximizes volume of occupancy with lightweight while providing the desired qualities of resiliency to deformation to impart the necessary ability to provide a cushioning function with maximum weight to volume characteristics. The ovoid shape is also desirable from the standpoint of precluding the tendency of one element nesting in another as nesting will only occur when one article is lined up exactly with the next adjacent one.

Reference is now made to Figures 9 and 10 which show a variation of the structure shown in Figure 6. In this embodiment element 65 is provided with a flange 66 around the periphery leading into a radius 68 and into an inwardly tapered wall 70 to a radius top 72, upper wall 74 and radius wall 76. Upper wall 74, as best seen in Figure 10, has a shape, in plan, defined by an outermost circular arc segment 78 and an inner arc segment 80 of a greater radius than the arc segment 78. Facing internal walls 80 are provided with each including a cutout segment 82 so that a substantial portion of facing inner walls 80 are open. Inner walls 82 are joined by an arcuate linking bridge 84 which, like the embodiment of Figure 6, provides a flexible pivot to permit relative movement of the two halves of the cushioned packaging elements to provide additional resiliency to assist in the shock absorbing function.

Reference is now made to Figures 11 and 12, where still another embodiment of the cushioned packaging element 87 of the present invention is shown. In this embodiment a generally circular flange 88 is provided leading through a radius 90 to a generally inward tapered upstanding wall 92 or through a radius 94 to a top wall 96 which may also have an opening (not shown) therein for weight reduction purposes. In the embodiment of Figures 11 and 12 provision is made to preclude nestability between one cushioned packaging element and the other by providing at one point in wall 92 a radius indentation 98 to preclude nestability between cushioned packaging elements unless indentation 98 of one element is precisely aligned with another. Reference is now made to Figures 13 and 14 for still another embodiment of the cushioned packaging element 99 of the present invention. In this embodiment the cushioned packaging element is formed with a generally circular flange element 100 leading to a generally tapered upstanding wall member 102 to a radius wall segment 104 leading to an inward radius wall 106. Thus radius wall 104 and inward radius wall 106 forms a compound curve which is particularly useful in resiliently absorbing shock forces without distortion to the basic shape of the cushioned packaging element. Preferably indentations 108 are formed in wall 102 to preclude the ability of adjacent elements to nest. In addition a plurality of cutouts 110 are provided in wall 108 to lessen the weight of the cushioned packaging element.

Each of the preferred embodiments of the cushioned packaging elements disclosed herein may also be made in sheet form, as shown in the embodiments of Figures 4 and 5, by appropriate mold forms which create sheet forms rather than individual cushioned packaged elements. When the cushioned packaging elements are used as separate individual elements, they are deposited loosely in a shipping container or package. The article to be shipped is deposited therein and additional cushioned packaging elements are added to insure that once the package is closed the article to be packaged is restrained from movement within the container and is cushioned from shocks which may be expected in transit. The preferred shapes for the cushioned packaging elements in conjunction with the use of a biodegradable molded cellulose fiber composition provide a resilient and flexibly elastically deformable cushioned packaging material which can absorb shock without permanently deforming or crushing to insure that the article being cushioned is not free to move about in its container.

Claims

What Is Claimed Is;

1. A cushioned packaging element formed of a biodegradable cellulose fiber material comprising a relatively thin walled element open at one end thereof and having said wall of a generally arcuate configuration to define an interior space so as to define an element having a relatively high volume to weight ratio, said element being configured to resiliently and elastically deform thereby to dissipate shock loads incident thereon without plastic deformation.

2. The cushioned packaging element as defined in Claim 1 including a peripheral flange formed adjacent said open one end.

3. The cushioned packaging element as defined in Claim l wherein said wall of generally arcuate configuration comprises a side wall extending from said open one end leading through a radius wall portion to a top wall.

4. The cushioned packaging element as defined in Claim 3 including means on one or more portions of said side wall for precluding ready nestability between packaging elements.

5. The cushioned packaging element as defined in Claim 1 wherein said wall of generally arcuate shape includes a first side wall extending from said one open end through a radius to a first top wall spaced from said one open end through a radius to a first wall segment to a short wall segment generally parallel to the plane defining said one open end to a second wall segment through a radius to a second side wall extending to said one open end whereby said element includes a pair of distinct segments linked by said short wall segment and wherein said distinct segments are hinged at said short wall segment.

6. The cushioned packaging element as defined in Claim 5 wherein said element is circular in cross- section parallel to said plane defining said one open end.

7. The cushioned packaging element as defined in Claim 5 wherein said element is oval in cross-section parallel to said plane defining said one open end.

8. The cushioned packaging element as defined in Claim 5 wherein each said short wall segment is arcuately shaped.

9. The cushioned packaging element as defined in Claim 5 wherein each said top walls are arcuately shaped.

10. The cushioned packaging element as defined in Claim 5 wherein each said first and second wall segments include portions thereof which are cutout to reduce the weight of said element.

11. The cushioned packaging element as defined in Claim 1 wherein said wall of generally arcuate shape includes a side wall extending from said one open end to a radius to a peripheral wall spaced from said one open end and curving toward said one open end to form a compound radiused wall to assist in dissipation of incident shock.

12. The cushioned packaging element as defined in Claim 11 including one or more cutouts in said side wall to reduce the weight of said element.

13. The cushioned packaging element as defined in Claims 1, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 wherein a plurality of said elements are closely spaced and interconnected by a common web of said material adjacent each said one open end.