NL2017518B1 - Foldable and Biodegradable Cushioning Sheet - Google Patents

Abstract

The invention is directed to a foldable and biodegradable cushioning sheet comprising a plurality of cushions, which sheet comprises a flexible base film and a plurality of cushions located on the top surface of the flexible base film; and wherein the cushioning sheet can be folded to provide a sturdy inside corner, wherein an object can be placed, such that the object is protected and if needed immobilized, for example during packing and transporting.

Description

P112855NL00

Title: Foldable and Biodegradable Cushioning Sheet

The invention is directed to a foldable cushioning sheet, a method of preparing such a sheet and a method of protecting an object using the sheet.

Cushioning material is material used to protect (or “cushion”) objects during transportation. Cushioning material is designed to deform in order to help keep levels or shock and vibration levels below that may damage the object inside a container. Cushioning material is typically applied between the object to be protected and the inner wall of a container in which the object is to be transported. A further functioning of cushioning material may be to immobilize the objects in a container, e.g. by blocking the movement of the object in a container.

One of the most used materials as cushioning material are expanded foams such as expanded polystyrene (EPS) foam, expanded polypropylene (EPP) foam and expanded polyurethane (PUR) foam A disadvantage of this material is that it is not biodegradable, such that it is increasingly abundant as a form of litter in the environment.

For example, there is a need for biodegradable cushioning material, which material is preferably also compostable, in order to reduce pollution of the environment.

An example of a biodegradable cushioning material is corrugated fiberboard. For example, US 6,000,545 describes a device constructed from a substantial flat sheet of corrugated cardboard with rigid panel members, which can be folded via fold lines formed in the cardboard (called hinge members). The panel members and hinge members have a specific size and shape such that an open corner can be folded for protecting the corners and edges or packed articles within a container and the like.

However, a disadvantage of cushioning material produced from corrugated fiberboard is that the material is rigid, such that it cannot be easily folded, unless specific folding lines are provided in the fiberboard.

Due, it lacks versatility, as it cannot be suitably folded around many different types of objects or objects with an irregular shape.

A further disadvantage of corrugated cardboard is that the material is not a good shock absorber in that it does not regain its original shape after impact. Thus, corrugated cardboard is often only capable of absorbing one shock, after which the object has a risk of damaging when it is subject to a possible second shock.

Another example of biodegradable cushioning materials are natural fibers, such as plant fibers. A further example of biodegradable cushioning material is material based on expanded polylactic acid (PLA).

WO 91/17932 describe a cushioned packaging material formed or biodegradable cellulose fiber material formed into shapes. A preferred shape described is a cushioned packaging material utilizing biodegradable cellulose fiber in sheet form. In this form, a series of domed protuberances are disposed in relatively closely spaced relationship and interconnected by a thin wall sheet at the bases to provide a continuous sheet of domed cushioned elements so that the sheet can fold along a line between protuberances so as to be wrapped about an article to be cushioned within a package.

However, a disadvantage of natural fiber cushioning material such as described in WO 91/17932 is that it cannot provide sufficient sturdiness to hold an object in place in a container (e.g. during transportation), especially at the corners of the object. As a result, the corners are insufficiently protected from impact. Also, such material is often not capable of or sufficiently retaining its shape when folded or wrapped around an object.

An object of the invention is to provide a cushioning material that does not suffer from one or more of the above disadvantages.

It is a further object of the invention to provide a biodegradable cushioning material that is both flexible, but can also provide excellent sturdiness if needed. Good sturdiness is for example required to immobile objects and to protect heavy objects or corners or objects. Cushioning material with a combination of flexibility and sturdiness are not known in the art, because flexible material will typically result in low sturdiness.

It is in particular an object of the invention to provide a multipurpose biodegradable cushioning material which is capable of cushioning objects or any shape. For example, the cushioning material should be both capable of cushioning an object by being folded around the object, as well as being capable of immobilizing objects, e.g. by sturdily cushioning the corners of objects.

It is further an object to provide a biodegradable cushioning material that can be used to provide a sturdy protective corner and an or can be immobilized.

At least one of these object has been provided with a foldable and biodegradable cushioning sheet including a variety of cushions, which sheet comprises a flexible base film (preferable or biodegradable plastic) and a plurality of cushions that are located on the top surface of the base film, the distance between adjacent cushions and the cushion height is chosen such that the sheet can be folded into a sturdy inside corner.

More in particular, the invention is directed to a foldable and biodegradable cushioning sheet including a variety of cushions, which sheet comprises

- a flexible base film; and

- a variety of cushions located on the top surface of the flexible base film; and cushions are distributed on the top surface of the base film in a rectangular grid pattern or horizontal and vertical grid lines, with each cushion positioned on a grid point, with a fold base cushion is defined as a cushion that has a first adjacent cushion and a second adjacent cushion, which first and second cushion do not lie on the same grid line, the cushion distance between at least one fold base cushion and its first adjacent cushion is such that the first adjacent cushion can be placed on top of said at least one fold base cushion by folding the portion or film located between these cushions upward along the side surface or said at least one fold base cushion and placing the side surface of the first adjacent cushion onto the top surface or said at least one fold base cushion, and the first adjacent cushion has a cushion height sufficient small that its top surface is not fully covered by the side surface of the first adjacent cushion aft there such placing; the cushion distance between said at least one fold base cushion and its second adjacent cushion is such that the side surface of the second adjacent cushion can be placed on top of the portion of base film located between said at least one fold base cushion and its second adjacent cushion, such placing causes the top surface of the second cushion to be contacted with the side surface of said at least one fold base cushion, and said said at least one fold base cushion has a cushion height sufficiently small that the top surface of the second adjacent cushion is not fully covered by the side surface of the fold base cushion after such placing;

with the preferred proviso that in case each cushion comprises a compressed fiber bundle and a cover film, the fiber bundle is not enclosed between the base film and said cover film.

The cushioning sheet of the invention can be easily folded around objects due to the flexible base film. The parts of the base sheet on which no cushion is provided is easy to fold. Therefore, the cushioning sheet of the invention can be used for cushioning materials or many different shapes, as well as objects with irregular shapes. A further advantage of the cushioning sheet of the invention is that it is very versatile, such that it can be used in many applications. The flexible film allows the sheet to be folded in many different ways (including, but not limited to folding it into an inside corner). Also, the film and cushions can be compressed if necessary. Like, the shape and size of a single sheet can be easily adjusted. Thus, the sheet can easily be used in containers or different shapes and sizes, as well as for protecting objects or different shapes and sizes. Also, single cushions are customizable due to the method according to which the sheets can be produced (see below), which opens up even more ways to obtain a well fitting packaging sheet for any product.

Furthermore, the flexible base film has the advantage that it allows for two adjacent cushions to protect protruding parts or an object between two adjacent cushions. Another advantage of the flexible base film is that one can fold a cushioning sheet 180 ° to produce a double layer of cushions. This may be desirable when wanting to fill up larger spaces or corners.

Moreover, the cushioning sheet can be used to cushion outside corners of objects and / or to immobilize objects in containers for transportation, such as a box. This is due to the presence of the fold base cushion and its adjacent cushions, which provide for a particular way in which the cushioning sheet can be folded according to the invention. The cushion distances and cushion heights are chosen such that the sheet can be folded into a sturdy inside corner (see Figures 7-8), the side or a corner or an object can be placed. The fold base cushion as defined above provides the basis or the inside corner. The fold base cushion can be stationary, while its first adjacent cushion and second adjacent cushion are folded into position (see Figures 1-4 and 7-8). The inside corner may be used to protect an object, in particular in a transportation container such as a box.

The method of protecting an object by folding the cushioning sheet into an inside corner, which method comprises the steps of

- assigning a folding base cushion, which may remain stationary during folding, as well as the folding base cushion, first and second adjacent cushion, which are to be folded;

- placing the first adjacent cushion on top of the folding base cushion by folding the portion of film located between the folding base cushion and the first adjacent cushion upward along the side surface of the folding base cushion and placing the side surface of the first adjacent cushion onto the top surface of the folding base cushion (first folding step); and

- folding a side surface of the second adjacent cushion onto the portion of base film located between the fold base cushion and the second adjacent cushion and placing the top surface of the second adjacent cushion against the side surface of the fold base cushion (second folding step ).

The folding mechanism is further explained in the Figures, which are discussed below.

The inside corner thus folded can be placed in a container and an object can be protected and / or immobilized by placing at least part of the object in the inside corner. When such a folded sheet is placed in the inside corner of a container, especially in an inside corner of a container, the folded sheet will not easily unfold. The first adjacent cushion can be kept in place by the container wall, such that it will not easily slip off the fold base cushion. Further, the second adjacent cushion can be pressed between the container wall and the fold base cushion. Due to the presence of the flexible film (especially the film in between the folded cushions), additional strength can be provided to the inside corner. The flexible film connecting the different cushions is relatively short and must be folded relatively tight along the cushions in a case or inside corner, such that the movement of the cushions in the inside corner is restricted. For example, the first adjacent cushion in the folded corner cannot move sideways, upwards or slide off the fold base cushion in the corner folded state. Whether, when the fold base cushion or a folded cushioning sheet is immobilized in the container (e.g. by clasping it in between the product and the container wall), the first and second adjacent cushions are also effectively immobilized.

Thus, the cushioning sheet is able to provide a rigid and sturdy inside corner in a container.

Figure 1 shows a side view or a part of a cushioning sheet according to an embodiment of the invention. The cushion distance c between cushions All and A2 is indicated in the figure, as well as the cushion length I or cushion All and the cushion height h of the cushions. The base film is indicated with a straight line. Each cushion in the embodiment depicted in this Figure has the same width, length and height. The cushion distance is also the same for each set or adjacent cushions.

Figure 2 shows a side view or a part of a cushioning sheet according to an embodiment of the invention, concerning the side surface of cushion A4 is folded onto the top surface of cushion Al. The cushion distance c between cushions Al and A2 is indicated in the figure, as well as the cushion length I or cushion Al, the cushion height h or cushion All and the cushion distance c between cushions All and A2. The base film is indicated with a straight line. Each cushion in the embodiment depicted in this Figure has the same width, length and height. The cushion distance is also the same for each set or adjacent cushions.

Figure 3 shows a side view or a part of a cushioning sheet according to an embodiment of the invention, with cushion A4 has been folded onto the portion of the base film connecting cushions Al and A4. The cushion distance c between cushions All and A4 is indicated in the figure, as well as the cushion length I or cushion A4 and the cushion height h or cushions.

The base film is indicated with a straight line. Each cushion in the embodiment depicted in this Figure has the same width, length and height. The cushion distance is also the same for each set or adjacent cushions.

Figure 4 shows a side view or a part of a cushioning sheet according to an embodiment of the invention, with cushion A4 has been folded onto the portion of the base film connecting cushions Al and A4. The cushions in Figure 4 have been pressed against each other, which is possible due to the flexibility of the base film. Each cushion in the embodiment depicted in this Figure has the same width, length and height. The cushion distance is also the same for each set or adjacent cushions.

Figure 5A shows an example of a rectangular grid pattern. Figure

5B shows an embodiment of the sheet of 11 cushions have been distributed over the rectangular grid pattern.

Figure 6 shows a top view of a cushioning sheet according to an embodiment of the invention in an unfolded state. Each cushion in the embodiment depicted in this Figure has the same width, length and height (y. The width (w) is equal to the length (S) and are in the Figure both indicated by I. The cushion distance (c) is also the same for each set of adjacent cushions On the bottom and right side of Figure 6, a side view of the cushioning sheet is given The outer dotted line in the figure depicts the base film.

Figure 7 shows a cushioning sheet according to an embodiment of the invention, which is folded into an inside corner. The first adjacent cushion A is folded onto the top surface or fold base cushion C, while the second adjacent cushion F is folded onto the intercushion film located between cushions F and C. Thus, cushions A, C and F form an inside corner. Each cushion in the edition depicted in this Figure has the same width (wj, length (Z) and height (hj. The cushion distance is also the same for each set of adjacent cushions. The outer dotted line in the figure depicts the base film .

Figure 8 shows a cushioning sheet according to an embodiment of the invention, which is folded into an inside corner. The cushioning sheet is the same as the one depicted in Figure 7, but the folding steps are conducted in a different order. The first adjacent cushion F is folded onto the top surface or fold base cushion C, while the second adjacent cushion is folded onto the intercushion film located between cushions A and C. Thus, cushions A, C and F form an inside corner. Each cushion in the embodiment depicted in this Figure has the same width (w), length (Z) and height (h).

The cushion distance is also the same for each set or adjacent cushions. The outer dotted line in the figure depicts the base film.

The term "fold base cushion" is defined as a cushion that has a first adjacent cushion and a second adjacent cushion, which first and second cushion do not lie on the same grid line. Like, the fold base cushions and its first and second adjacent cushion lie in a (two-dimensional) corner on the cushioning sheet.

The term "cushion row" is defined as a row of cushions positioned on one of the grid lines or the rectangular grid pattern. In case a cushion row is positioned on a horizontal grid line, it may be referred to as a horizontal cushion row. In case a cushion row is positioned on a vertical grid line, it may be referred to as a vertical cushion row.

The term "rectangular grid pattern" refers to a pattern composed of a first series or parallel lines and a second series or parallel lines, being the lines of the second series are perpendicular to the lines of the first series. The lines are called grid lines. The lines of one of the two series are called horizontal grid lines; the lines of the other series are called vertical grid lines. The intersection point of two lines is called a grid point. The distance between any two adjacent lines in a series is the same. In a preferred embodiment, the rectangular grid pattern is a square grid pattern. In a square grid pattern, the distance between any two adjacent lines in the first series is the same as the distance between any two adjacent lines in the second series. Regarding the orientation of the pattern, the rectangular grid pattern should be chosen in the plane of the unfolded base film. Which direction in the cushioning sheet is chosen as horizontal and which direction as vertical is not important.

The “cushion distance” between two adjacent cushions is defined as the shortest distance between the two adjacent cushions, measured in the plane or the top surface of the unfolded base film. The cushion distance is either measured parallel to the horizontal grid lines or the rectangular grid pattern (in case the adjacent cushions lie on a horizontal cushion row) or parallel to the vertical grid lines or the rectangular grid pattern (in the case the adjacent cushions lie on a vertical cushion row). Two cushions are in particular considered adjacent if they are on the same gridline and are positioned on adjacent grid points.

The “cushion height” is defined as the longest distance passing through the interior of the cushion (made up by the cushioning material), the distance being measured perpendicular to the grid lines. In other words, the “cushion height” or a certain cushion refers to the longest distance between the cushion top and the top surface of the base film, measured perpendicular to the top surface of the unfolded base film.

The term "intercushion film" refers to the portion of flexible film located between and connecting two adjacent cushions. For, the length of the intercushion film between two adjacent cushions is typically the same length as the cushion distance between these two cushions.

The “cushion length” or a cushion is defined as the longest distance passing through the interior of the cushion (made up by the cushioning material), the distance being measured parallel to the vertical grid lines. The distance is thus measured in a plane parallel to the top surface of the unfolded base film. Typically, the distance is measured in or just above (e.g., 0.5 cm above) the plane of the top surface of the base film.

The “cushion width” or a cushion is defined as the longest distance passing through the interior of the cushion (made up by the cushioning material), the distance being measured parallel to the horizontal grid lines. The distance is thus measured in a plane parallel to the top surface of the unfolded base film. Typically, the distance is measured in or just above (e.g., 0.5 cm above) the plane of the top surface of the base film.

The cushion height, length and width are measured with the cushioning sheet in unfolded state, unless specifically indicated otherwise.

The term "adjacent" as used refers to two cushions that are positioned on adjacent grid points.

The term "horizontally adjacent" as used refers to a cushion being adjacent to another cushion in a direction parallel to the horizontal grid lines. The term "vertically adjacent" as used refers to a cushion being adjacent to another cushion in a direction parallel to the vertical grid lines. For example, the at least one fold base cushion and its first cushion are either horizontally or vertically adjacent. In case they are horizontally adjacent, the least one fold base cushion and its second cushion are vertically adjacent. In case they are vertically adjacent, the least one fold base cushion and its second cushion are horizontally adjacent.

The term "inside corner" refers to a three-dimensional corner formed by a bottom surface (provided by the fold base cushion) and two intersecting walls (formed by the first and second adjacent cushion). The angle between the intersecting wall may be in the range of 80-100 °, preferably 85-95 ° C, even more preferably about 90 °. An object can be placed in the inside corner for protection.

The cushioning sheet of the invention comprises a base film and a variety of cushions located on the top surface of the base film. The term "various of cushions" as used refers to at least one cushion.

A cushion comprises or is made of cushioning material. Preferably, the shape of the cushioning material corresponds to the shape of the cushion as described in detail below. The cushioning material may be solid or hollow. In a preferred embodiment, the cushioning material makes up the entire cushion. In another embodiment, the cushioning material makes up the majority of the cushion, typically more than 80 wt.%, For example more than 90 wt.% Of the material.

A cushion may for example consist of a single piece of shaped cushioning material. The shape of the shaped cushioning material conforms to the shape of the cushion as described in detail below. A cushion may also consist of multiple pieces or shaped cushioning material.

In this case, the different pieces together will make up the shape of the cushion. A shaped cushioning material may be solid or hollow. Preferably at least one (more preferably each) or the multiple of cushions consists of a single or multiple pieces of shaped cushioning material.

The cushion is located on the top surface of the base film. The cushion is fixed to the base film. In particular, the bottom surface of the cushion may be fixed to the top surface of the base film. For example, the cushion and base film may be fixed to each other simply because they are one and the same material or structure. Such a structure may be prepared in one step as described for the method of the invention further below. The cushion may also be fixed to the base film due to the cushion being attached to the base film by any suitable means. Means for attaching a cushion to the flexible base film are discussed further below with respect to the method of the invention.

In one embodiment, the cushion does not include an outer covering to hold or cover the cushioning material. For example, the cushion may not include a second flexible film (in addition to the base film) that covers the cushioning material. In particular, the cushioning material does not have to be enclosed between the base film and a second flexible film (cover film).

In another embodiment, however, the cushion may further include at least one flexible film in addition to the flexible base film. Such an additional flexible film may also be referred to as the cover film. In this embodiment, the cushioning material makes up the interior of the cushion. The cushioning material may be enclosed by the cover film, for example in the case of the cushioning material is an expanded plastic, such as PLA. The cover film may cover at least part or all of the outer surface of the cushioning material. In case the cushioning material is not a compressed fiber bundle, the cushioning material may also be enclosed between the base film and said second flexible film (cover film). In the latter case, part of the base film and part of the least one cover film may be a flexible envelope or “pillowcase” (exterior of the cushion), the cushioning material is stuffed. The materials that can be used for the cover film are the same as described below for the base film. The base film may be made of the same material as the cover film, but may also be made of a different material. For example, both the base film and the cover film may be made of polymer material, such as PLA based material.

The flexible base film or the cushioning sheet is generally flat. The cushions were on top of the base film. In particular, the cushions are fixed to the top surface of the base film. The cushioning material is typically fixed to the base film at their base. Two cushions are connected to each other by the base film (and possibly the cover film if present). Since the base film is flexible, the different cushions can be folded along the interconnecting portions of the base film.

The cushioning sheet is biodegradable, which means that the sheet is constructed from biodegradable materials, preferably compostable materials. Preferably, each material present in the cushioning sheet is also compostable. A compostable material can be degraded by micro-organisms.

Typically, a compostable material is capable of being degraded by microorganism for at least 50%, preferably 70%, more preferably 90% within 52 weeks, preferably 26 weeks, even more preferably within 12 weeks. Each of the base film, cover film and cushioning material are biodegradable, and preferably also compostable.

The cushioning material may be or may be a solid or foamed polymer or a material based thereon. For example, the polymer may be an extruded or expanded polymer or polymer foam. The polymer may be selected from the group consisting of polylactic acid (PLA), starch-based polymers, cellulose-based polymers, biodegradable polyesters and biodegradable biopolymers and blends. Preferably, an expanded polymer, in particular expanded PLA is used as the polymer. The cushion may or may not include fiber material such as a fiber bundle. A material based on a certain polymer comprises at least 50 wt.%, Typically at least 70 wt.%, More typically at least 90 wt.% Of that polymer.

The cushioning material may be a fiber material, such as cardboard, fiberboard, wood fibers or natural fibers from plant or animal sources. The fiber material may be compressed. Compressing can be advantageous in view of receiving the desired shape of the cushion and / or for shock-absorbing properties.

The cushioning material may also be a material including fiber material. In this case, the cushioning material may be waste material. Such waste material can then be upcycled as cushioning material.

The cushioning material may be a compressed fiber bundle. The compressed fiber bundle is a bundle comprising fibers, which fibers have been compressed, for example during or prior to enclosing the fibers between the base film and the cover film. The fibers may in particular be natural fibers. The natural fibers may be from plant or animal sources. Suitable natural fibers from plant source may be stable fibers (such as plant pieces, straw, wood or wood pulp) and bast fibers (such as cotton, flax, jute, hemp). Suitable natural fibers from animal sources are wool, hair, silk fibers and feathers. In a preferred embodiment, natural fibers originate from waste material, such as three plant fibers.

The fiber bundle may only include fibers. However, other components than fiber may be present in the bundle. For example, structuring agents may be present, to provide the fibers with an enhanced structure, e.g., enhanced strength. For example, an adhesive may be present in order to keep the bundles together. Also, certain fungi may be grown through the fibers to provide them with more strength. Preferably, the fiber bundle comprises at least 40 wt.% Fibers, more preferably 60 wt.% Fibers, even more preferably at least 80 wt.% Fibers, even more preferably at least 90 wt.% Fibers. The remainder of the material present in the fiber bundle is non-fiber material, e.g. micro-organisms or sand.

The density of the cushions in the cushioning sheet is not particularly critical and may be in the range of 10 kg / m ³ and 600 kg / m ³ , preferably 20-500 kg / m ³ . The particular density depends on the application or cushioning sheet, for example the type of object that the sheet is meant to protect. In case the cushioning material comprises or consists of expanded polymer, the density of the cushions may be 10-50 kg / m ³ , preferably 15-40 kg / m ³ .

The base film (and / or cover film if present) may be composed of a material selected from the group consisting of starch, cellulose, biopolymers, biodegradable polyesters and blends. The base film (and / or cover film if present) is preferably made of a material that is both flexible and strong, in particular with respect to tearing. The base film (and / or cover film if present) may be a biodegradable plastic, for example a biodegradable polymer film. However, other materials can also be used, such as paper. Also, thicker films may be used, provided they are flexible. For example, an expanded polymer or polymer foam layer may be suitably used as a base film. Such a thick flexible film may also be referred to as a flexible base layer.

The flexible base film is preferably a plastic. Suitable plastics are for example starch-based plastics, cellulose-based plastics, polylactic acid plastics, biodegradable polyesters and biodegradable biopolymers. Awesome, the base film (and / or cover film if present) may be a plastic film, the plastic is selected from the group of starch, cellulose, polylactic acid, biodegradable polyesters, biodegradable biopolymers and blends. An example of a suitable blend is polycaprolactone. The plastics are preferably thermoplastic. This allows the plastic to be melted together, which is desirable in view of the preparation method or the cushioning sheets.

The thickness of the base film may vary widely and is dependent on the type of material used. Generally, it lies in the range or 10 pm to 50 mm. The base film (and / or cover film if present) may have a thickness of 10-200 pm, preferably 25-120 pm, more preferably 40-70 pm. Such a thin thickness is especially suitably for polymer films. A thin thickness provides flexibility to the film and is advantageous from an economic perspective. The thickness given in the above ranges generally also provides sufficient strength, such that the cushions will not tear during use. A thickness of less than 10 pm may also be suitably used, but depending on the type of film used it may increase the risk of tearing. In case the base film is made of expanded polymer or polymer foam, the thickness of the base film is not particularly critical and depends on the size of the cushioning sheet. For example, such films can have a thickness of 1-50 mm, such as 2-25 mm or 3-10 mm.

Each cushion is positioned on a grid point or the rectangular grid pattern. The cushion is considered to be positioned on a grid point if any part of the cushion lies on the grid point. Preferably though, the center of the base surface or each cushion lies on the grid point. The base surface of a cushion is the surface in the plane of the base film.

In a preferred embodiment, there is no cushion located on the grid point diagonal or a fold base cushion and adjacent to the first and second adjacent cushions, as the presence of a cushion on this grid point may interfere with the folding or an inside corner.

As already stated above, the cushioning sheet can be folded into an inside corner. In order to be able to do this, the cushioning sheet needs at least one fold base cushion with suitable cushion distances between its first and second adjacent cushion, as well as suitable cushion heights for these three cushions. These can be best expressed relative to each other and the cushion widths and lengths. Below, a number of preferred ratios for different cushion distances and cushion heights are given.

For the first folding step (folding the adjacent cushion on top of the fold base cushion), it is important that the height of the first adjacent cushion is small enough that there is still sufficient room for an object to be placed on the top surface of the fold base cushion after the folding step. Furthermore, the distance between the cushions should be about the same length and / or width as the cushion height or the first adjacent cushion, such that the intercushion film can be tightly folded around the side of the fold base cushion. Forever, the sheet fulfills at least one, but preferably all of the following ratios.

In case the first adjacent cushion is a cushion vertically adjacent to the least one fold base cushion, the ratio between the cushion height or the first adjacent cushion and the cushion length or the fold base cushion is typically narrower than 1, preferably between 0.1 and 0.9, more preferably between 0.2 and 0.8, more preferably between 0.3 and 0.7, more preferably between 0.4 and 0.65. In case the first adjacent cushion is a cushion horizontally adjacent to the least one fold base cushion, the ratio between the cushion height or the first adjacent cushion and the cushion width of the fold base cushion is typically narrower than 1, preferably between 0.1 and 0.9, more preferably between 0.2 and 0.8, more preferably between 0.3 and 0.7, more preferably between 0.4 and 0.65. Why, when the side surface of the first adjacent cushion is placed on the top surface of the fold base cushion, there is a sufficient room on the top surface of the fold base cushion for an object (or a part thereof) to be placed thereon . Also, minimum height of the first adjacent cushion described above contributes to this cushion slipping back off the top surface or the fold base cushion.

Furthermore, the ratio between the cushion distance between the at least one fold base cushion and its first adjacent cushion and the cushion height of the at least one fold base cushion is typically between 0.5 and 1.5, preferably between 0.9 and 1.3, more preferably between 0.95 and 1.2 more preferably between 1 and 1.1. Between, the portion or flexible film between these two cushions is about the same size as the height or the least one fold base cushion. Thus, the portion of flexible film is large enough that the first adjacent cushion can be placed on top of the fold base cushion, and small enough that the two cushions can be tightly folded against each other, which is important for the sturdiness of the inside corner to be folded.

For the second folding step (folding the adjacent cushion up onto the intercushion film), it is important that the height of the fold base cushion is small enough that the second adjacent cushion when standing up is higher than the fold base cushion. Furthermore, the distance between the cushions should be about the same length and / or width as the cushion height or the second adjacent cushion, such that the second adjacent cushion can fit onto the intercushion film when folded into an upright position. Forever, the sheet fulfills at least one, but preferably all of the following ratios.

In case the second adjacent cushion is a cushion vertically adjacent to the least one fold base cushion, the ratio between the cushion height or the fold base cushion and the cushion length or the second adjacent cushion is typically narrower than 1, preferably between 0.1 and 0.9, preferably between 0.2 and 0.8, more preferably between 0.3 and 0.7, more preferably between 0.4 and 0.65. In case the second adjacent cushion is a cushion horizontally adjacent to the least one fold base cushion, the ratio between the cushion height or the fold base cushion and the cushion width or the second adjacent cushion is typically narrower than 1, preferably between 0.1 and 0.9, preferably between 0.2 and 0.8, more preferably between 0.3 and 0.7, more preferably between 0.4 and 0.65. Why, when the second adjacent cushion is folded onto the portion of flexible film, the second adjacent cushion standing will be higher than the cushion height of the fold base cushion, such that it forms a sufficient high wall around the top surface of the fold base cushion. Also, the height is large enough that the second adjacent cushion does not slip onto the top surface or the fold base cushion.

Furthermore, the ratio between the cushion distance between the at least one fold base cushion and its second adjacent cushion and the cushion height of the second adjacent cushion is typically between 0.5 and 1.5, preferably between 0.9 and 1.3, more preferably between 0.95 and 1.2 more preferably between 1 and 1.1. Thus, the cushion distance is about the same size as the height. Can, the second adjacent cushion can be folded sufficiently tight onto the portion or flexible film between the at least one fold base cushion its second adjacent cushion. A sufficiently tight fit is important for the sturdiness or the inside corner to be folded. Since the cushions can often be slightly compressed when folding, the ratio may be higher than 1.

As explained above, the cushioning sheet has at least one fold base cushion such that the sheet can be folded into an inside corner using this cushion as a base. However, in a preferred embodiment, the cushioning sheet comprises more than one fold base cushion. This provides more locations at which the sheet can be folded into an inside corner. This provides the cushioning sheet with more flexibility in its use, for example with respect to the position of the corner or by folding multiple corners.

For example, the cushion distance and cushion height needed to fold the sheet into an inside corner preferably applies to more than one fold base cushion and its first and second adjacent cushion. Preferably, these apply to at least half, preferably at least 90%, more preferably all of the fold base cushions and their respective first and second adjacent cushions present in the cushioning sheet. Also, the above ratios for the first and second folding step apply to at least half, preferably to at least 90%, more preferably to all of the fold base cushions and their respective first and second adjacent cushions present in the cushioning sheet.

Preferably, any fold base cushion in the cushioning sheet can be used to fold the sheet into an inside corner. This object is for example achieved when any two adjacent cushions in the cushioning sheet are capable of being folded according to the first folding step. This object is also achieved when any two adjacent cushions in the cushioning sheet are capable or being folded according to the second folding step. The ratio between the cushion height or any of the cushions and the cushion length or a cushion adjacent to it is typically between 0.1 and 0.9, preferably between 0.2 and 0.8, more preferably between 0.3 and 0.7, more preferably between 0.4 and 0.65. The ratio between the cushion height or any of the cushions and the cushion width or the cushion adjacent to it is typically between 0.1 and 0.9, preferably between 0.2 and 0.8, more preferably between 0.3 and 0.7, more preferably between 0.4 and 0.65. The ratio between the cushion distance between any two adjacent cushions in a vertical cushion row and the cushion height or at least one (but preferably both) or these two adjacent cushions is typically between 0.5 and 1.5, preferably between 0.9 and 1.3, more preferably between 0.95 and 1.2 more preferably between 1 and 1.1. The ratio between the cushion distance between any two adjacent cushions in a horizontal cushion row and the cushion height or at least one of these two adjacent cushions is typically between 0.5 and 1.5, preferably between

0.9 and 1.3, more preferably between 0.95 and 1.2 more preferably between 1 and 1.1.

Generally, when folding two adjacent cushions, the portion of flexible film located between and connecting the two adjacent cushions (intercushion film) is preferably folded tightly along the surface or one of the adjacent cushions. Thus, a sturdy and solid inside corner can be formed. In order to be able to tightly fold the intercushion film along one of the two adjacent cushions, it is important that a suitable ratio between the cushion distance and cushion height is selected. As also mentioned above, this ratio preferably lies between 0.9 and 1.3, more preferably between 0.95 and 1.2 more preferably between 1 and 1.1. Thus, they are about the same, such that the intercushion film can be covered for a substantial part (e.g. more than 50% of its surface) by the side surface or one of the adjacent cushions.

Another advantage of the intercushion film is that different cushions can be pressed together if necessary, forming a continuous solid protective wall.

The shape of the cushions is not particularly critical, provided that they are capable of folding according to the first and second folding step if necessary. The cushions preferably have a rectangular cuboid shape (e.g. a cube) or a dome shape. Any corners and / or edges of the rectangular cuboid or dome may be rounded. In case the cushions are rounded, the side surface and top surface of the cushion may sometimes not be very distinct from each other. In this case, the top surface of a cushion may be considered to have a size equal to the bottom surface of the cushion. The bottom surface is the area of the cushion that lies in the plane of the base film. The top surface is the surface that lies furthest away from (in particular opposite to) the bottom surface, with the side surface of the cushion lying in between the top and bottom surface. The cushions may also have a cylindrical shape, e.g. a circular or elliptic cylinder. In this case, the circular or ellipitic surfaces will form the bottom and top surfaces of the cushion.

The size of the cushions is not critical. Typically, the cushion height is 1-20 cm, preferably 2-10 cm, e.g. 3-7 cm. Suitable heights are at least 3 cm or at least 4 cm. By not choosing the minimum height too low, there is sufficient room for the object to lie when the sheet is folded into an inside corner. The cushion distance between any two adjacent cushions may be chosen within the same ranges as mentioned above for the cushion height.

In a preferred embodiment, the cushion length and cushion width or the cushions are about the same. The cushion width and length are typically larger than the cushion height or a cushion. The above ratios can be used to obtain a more accurate value for the width and length of the cushions.

The cushioning sheet of the invention must include a minimum of three cushions in order to be able to fold and inside corner. However, the cushioning sheet preferably comprises at least four cushions, more preferably six cushions, for example at least 12 cushions. The shape of the cushioning sheets is not critical and may be irregular, for example an Lshape.

Preferably, the cushions are or similar shape and size. This is preferred, because in this way they can easily be prepared using the molding method described below. Like, when in the description above or below the cushion height, width, length or distance is defined for a single cushion or for the least one cushion, such a value preferably applies to at least 90% of the cushions, more preferably to each cushion in the cushion sheet.

In a preferred embodiment, at least part of the cushions are connected to each other by a portion of base film (in particular, the intercushion film) that comprises a tear line for facilitating the removal of cushions from the cushioning sheet. An example of a suitable tear line is a line of perforated holes. A suitable tear line may be parallel to the grid lines for example.

The invention is further directed to a method for protecting an object with the cushioning sheet of the invention, for example by wrapping the sheet around the object or by folding the sheet in the specific inside corner described above. The object and one or more cushioning sheets may be placed for this purpose in a container, for example for transportation or a container. The cushioning sheet forms a protective boundary between the inside of the container and the object. When folding the inside corner, an object can rest on the part of the top surface of the fold base cushion that is not covered by one of its adjacent cushions. In particular, an outside corner can be protected using the folded inside corner. Also, the corners can be suitably used to immobilize objects.

The invention is further directed to methods for preparing the cushioning sheet of the invention.

A first method with which the cushioning sheet or the invention may be prepared is a method with which the cushioning sheet is formed in a mold. In the mold, the base film and the cushions may be formed simultaneously in a single molding step. The cushioning sheet may be formed in the mold in one single piece, including both the base film and cushions. The shape of the mold cavity will correspond in such a case to the desired final shape of the cushioning sheet. The method may include the step of providing a polymer solution in the mold cavity and hardening the polymer solution to obtain the cushioning sheet.

A second method with which the cushioning sheet of the invention may be prepared comprising the steps of providing a base film and attaching one or more cushions to the base film.

The cushions can be attached to the base film by any suitable means. In case the flexible base film or the exterior of the cushion or both are made of a thermoplastic material, the cushion is preferably attached to the flexible base film by melting. In this embodiment, the thermoplastic film or thermoplastic exterior of the cushion is heated at the position at which the connection between the cushion and base film is to be formed. The thermoplastic material will soften during heating. Subsequently, the cushion and base film are pressed together to attach the cushion to the base film, effectively using the softened thermoplastic material as adhesive.

Upon cooling, the thermoplastic material will solidify and form a bond between the cushion and the base film. In this embodiment, the thermoplastic material acts effectively as a hot melt adhesive.

The cushion may also be attached to the base film by means of an adhesive, glue or tape. The cushion may also be attached to the base film by mechanical means, such as a mechanical fastener, e.g. by one or more (biodegradable) screws, pins or nails.

The means described above generally provide a sufficiently strong bond between the base film and the cushions. During packaging, when the sheet is in folded form, the packaged product will mainly be in contact with the top side of the cushions. In such a case, the forces typically applied to the side of the cushions during packaging are relatively low. For, the bond between the base film and the cushions does not need to be particularly strong.

Using the above methods, it is easy to produce the cushioning sheets or the invention in a practical and standardized way. An advantage of these methods is that it is very easy to make a sheet with cushions or a standardized size. This makes it possible to practically easily adapt the cushioning sheet to the need of the packaging.

The material of the flexible base film and cushions to be used in the methods of the invention is as described above for the cushioning sheet.

In case a cushioning sheet or a specific form is required, the method of the invention may further include the step of removing part of the cushions from the cushioning sheet, for example by cutting or tearing. In this way, irregularly shaped (e.g. non-rectangular) sheets can be produced if necessary. To facilitate the removal of cushions, the intercushion film may be provided with a tear line.

It is further possible to combine two or more cushioning sheets into one larger cushioning sheet. For example, the base film or two cushioning sheets can be melted together by heating if the base film is made from thermoplastic material. Thus, an even larger variety of shapes and sizes can be obtained.

Claims (17)

CONCLUSIONS A foldable and biodegradable cushion sheet comprising an amount of cushions, which sheet comprises - a flexible base film; and - a quantity of pillows located on the top of the flexible base film; and wherein the pads are distributed over the top of the base film in a rectangular grid pattern of horizontal and vertical grid lines, with each pad placed at a grid point, a folding base pad defined as a pad that a first adjacent pad has a second adjacent pad, first and second cushion is not on the same grid line, the cushion distance between at least one folding base cushion and its first adjacent cushion being such that the first adjacent cushion can be placed on the top of the at least one folding base cushion by the portion of the film located between folding this cushion upward along the side of the at least one folding base cushion and placing the side of the first adjacent cushion on the top of the at least one folding base cushion, and wherein the first adjacent cushion has a cushion height sufficiently small that the the top is not completely covered dt through the side of the first adjacent cushion after such placement; and wherein the cushion distance between the at least one folding base cushion and its second adjacent cushion is such that the side of the second adjacent cushion can be placed on top of the portion of the base film located between the at least one folding base cushion and its second adjacent cushion, such placement ensures that the top of the second cushion is in contact with the side of the at least one folding base cushion, and wherein the at least one folding base cushion has a cushion height sufficiently small that the top of the second adjacent cushion is not completely covered by the side of the folding base pad after such placement; with the proviso that if each pad comprises a compressed fiber bundle and a cover film, the fiber bundle is not enclosed between the base film and said cover film. The cushion sheet of claim 1, wherein each cushion has a cushion length and a cushion width, the cushion length of a cushion being defined as the longest distance passing through the inside of the cushion, the distance being measured parallel to the vertical grid line; and wherein the cushion width of a cushion is defined as the longest distance that passes through the inside of the cushion, the distance being measured parallel to the horizontal grid line; and wherein the ratio between the cushion height of any of the cushions and the cushion length of any cushion adjacent thereto is less than 1, preferably between 0.1 and 0.9, more preferably between 0.2 and 0.8, more preferably between 0.3 and 0.7, more preferably between 0.4 and 0.65; and wherein the ratio between the cushion height of any cushion and the cushion width of any cushion adjacent thereto is less than 1, preferably between 0.1 and 0.9, more preferably between 0.2 and 0.8, with larger preferably between 0.3 and 0.7, more preferably between 0.4 and 0.65; and wherein the ratio between the cushion distance between any two adjacent cushions in a vertical cushion row and the cushion height of any of the two cushions is between 0.5 and 1.5, preferably between 0.9 and 1.3, at larger preferably between 0.95 and 1.2, more preferably between 1 and 1.1; and wherein the ratio between the cushion distance between any two adjacent cushions in a horizontal cushion row and the cushion height of any of the two cushions is between 0.5 and 1.5, preferably between 0.9 and 1.3, at larger preferably between 0.95 and 1.2, more preferably between 1 and 1.1. Pillow cushion according to one of the preceding claims, wherein the flexible base film is composed of a compostable plastic. Cushion sheet according to any of the preceding claims, wherein the flexible base film is composed of a plastic selected from the group consisting of starch, cellulose, biopolymers, biodegradable polyesters and blends thereof. Pillow cushion according to claim 3 or 4, wherein the plastic is a thermoplastic. Cushion sheet according to any of the preceding claims, wherein the density of the fibers in the cushions is in the range of 10 µm to 5 cm. Pillow cushion according to one of the preceding claims, wherein the cushion is based on a hollow cushion material. The cushion sheet of claim 7, wherein the cushion consists of a single piece or multiple pieces of cushion material. Cushion sheet according to any of the preceding claims, wherein the cushion material is a polymer slider, an extruded polymer or an expanded polymer, the polymer being selected from the group consisting of polylactic acid (PLA), polymers based on starch, polymers based on cellulose, biodegradable polyesters and biodegradable biopolymers and blends thereof. Cushion sheet according to one of the preceding claims, wherein both the base film and the cushion are made of a polylactic acid-based material. The cushion sheet of any one of claims 1-8, wherein the cushion material is selected from cardboard or fiberboard. 12. Cushion sheet according to any of claims 1-11, wherein at least part of the cushions are connected to each other by a piece of base foil comprising a tear line for simplifying the removal of cushions from the cushion sheet. A method of making the cushion sheet according to any of claims 1-12, which method comprises the steps of - providing a base film; and - fixing one or more pads on the base foil, preferably by means of an adhesive. The method of making the cushion sheet according to any of claims 1-11, wherein the cushion sheet is formed from a single piece in a mold. 15. Method for protecting an object with the cushion sheet according to claims 1-12, which method comprises the steps of - assigning a folding base pad, which can remain stationary during folding, as well as the first and second adjacent pads of the folding base pad, which are to be folded; - placing the first adjacent cushion on the top of the folding base cushion by folding up the portion of the film located between the folding base cushion and the first adjacent cushion along the side of the folding base cushion and placing the side of the first adjacent cushion on the top of the folding base cushion; and - folding a side of the second adjacent cushion on the portion of the base film located between the folding base cushion and the second adjacent cushion and placing the top of the second adjacent cushion against the side of the folding base cushion; - placing at least a portion of the object in the 25 inner corner obtained with the preceding steps.