JP2003502237A - Stretchable protective cover - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides a flexible cover 10 comprising at least one sheet of flexible sheet material that is assembled to form a partially open container having a peripheral edge. provide. The cover 10 is extensible in response to the force exerted by the article, item, or material, and the cover 10 is placed over the article, item, or material, and the article, item, within which the cover 10 is placed. Alternatively, the volume of the cover 10 is increased to accommodate the material.

Description

Detailed Description of the Invention

FIELD OF THE INVENTION The present invention relates to flexible covers of the type commonly utilized in the protection of various articles, items, and / or materials.

BACKGROUND OF THE INVENTION Flexible covers, especially those made from relatively inexpensive polymeric materials, have been widely adopted for the protection of various articles, items, and / or materials. The cover is
Used by itself, or in combination with other covers or opposite surfaces, to partially or completely "cover" or shield articles, items, and / or materials. May be.

As used herein, the term “flexible” is such that a material is compliant to externally applied forces and is yieldable, in particular repeatedly flexed or bent. Used to refer to materials that can.
Thus, "flexible" is a term that is inflexible, rigid (ri).
Gid, or unyielding, is substantially the opposite in meaning. Materials and structures that are flexible can therefore change shapes and structures to accommodate external forces and conform to the shape of objects that come in contact with them without loss of their integrity. A commonly available type of flexible cover is one that has consistent stretchability, tensile properties, and / or consistency throughout the structure of the cover.
Alternatively, it is typically formed from a material having physical properties such as extensibility.

[0004] For such flexible covers, it is often difficult to provide a cover that exactly accommodates the size and volume of the articles placed therein. Incomplete coverage necessarily leaves some of the article or item unprotected from external elements. As a general matter, covers are typically provided when the exact dimensions are not known in advance and / or where it is desired that a given cover fit one or more molds or articles of one or more sizes. It is formed with dimensions that are larger than necessary than would be expected to ensure that the article or item is completely covered. Another problem that often occurs is that when the article is relaxed (l
An oosy-fitting cover is that it may undergo a sliding or wind effect, which can shift the cover over the article and / or completely separate it from the article.

Accordingly, it is desirable to provide a flexible cover that can better fit the volume and / or dimensions of the article, item and / or material being protected.

SUMMARY OF THE INVENTION The present invention is assembled to form a partially open container having a perimeter.
A flexible cover is provided that includes at least one sheet of flexible sheet material.
The cover is extensible in response to a force exerted by the article, item or material and the cover is placed over the article, item or material to cover the article, item or material placed therein. Increase the volume of the cover to accommodate.

DETAILED DESCRIPTION This specification includes claims that particularly point out and distinctly claim the invention, which is described below with reference to the accompanying drawings, in which like numerals refer to like elements. It will be better understood from the description.

Flexible Bag Configuration: FIG. 1 shows the preferred embodiment shown here of a flexible cover 10 according to the present invention. In the embodiment shown in FIG. 1, the flexible cover 10 has a rim 30
It includes a cover body 20 formed from a sheet of flexible sheet material. Cover 10
Is suitable for housing and protecting a wide variety of articles, items and / or materials, which may be initially planar and may be a general two-dimensional or three-dimensional representation of the articles, items or materials to be covered. It may be formed in advance in a three-dimensional shape.

Depending on the desired application and the article, item and / or material to be protected, the cover 10 may be a fully-enclosed coke.
A closure may be included to form a verging) and may include an elasticized edge that engages the edge of the article. Mounting means, eg V
ELCRO (registered trademark) interlocking mechanical fastener (inter)
locking mechanical fasteners, activatable and protected or exposed adhesive systems, grommets, laces, fobs (f
ob) and the like may also be included to support the cover on the article by external means or to support the cover around the article.

FIG. 1 shows a plurality of regions extending across the cover surface. Area 4
0 comprises an array of deformed portions deeply embossed in the flexible sheet material of the cover body 20, while the region 50 comprises an undeformed region in between.

According to the present invention, the body portion 20 of the flexible cover 10 has the ability to elastically stretch to respond to the forces exerted outwardly by the article, item and / or material to be protected and the tensile limit of the material. A flexible sheet material that combines the ability to impart additional resistance to elongation before reaching. By controlling the elongation in each direction by this combination of properties, the cover can easily be initially stretched in response to external forces exerted by the protected article, item and / or material. These elongation properties increase the inner volume of the cover by extending the length of the cover material. This allows the cover to optionally cover the geometry and surface topography of the article, item or material to be covered.
The ability to adapt to the size, shape and geometry of the article, item or material being covered by stretching, depending on the need for conformity with

Further, while it is preferred herein to comprise substantially the entire cover body from a sheet material having the structure and features of the present invention, in some circumstances, rather than the entire cover body, one or more portions or locations thereof. It may be desirable to provide such a material only to one. For example, a band of such a material with a desired stretch direction can be provided and a complete annular band can be formed around the cover body to provide more localized stretch.

The product use of the cover of the present invention is, for example, a motor vehicle.
vehicle), eg covers for cars, trucks, ships, aircraft, farm equipment and railway equipment; Bicycle covers: outdoor cookware, eg gas grills or charcoal grills: indoor and outdoor equipment: barbershop drapery. Clothes (pe
bandages; painted covers and drapes; hygiene or aseptic items such as dental and surgical instruments; tablecloths; infant seat covers; laboratory table covers; automotive glass protective covers; bicycle and motorcycle seats Covers: Umbrella covers; Light covers; Toilet seat covers; Airplane seat covers; Covers for motor vehicle parts that are easily damaged during transportation; Insulating covers for beverage containers; Covers for firewood or timber; In a limited sense, the sheet material does not form a cover by folding and sealing operations, but rather has sufficient stretch properties, i.e., from an initially flat sheet material, to form a suitably tensed cover. It may have elongation properties.

Representative Material: In order to better illustrate the structural features and effects of the flexible cover according to the present invention, in FIG. 2A, a cover body 20 as shown in FIG. 1 is formed. A greatly enlarged partial perspective view of a section of sheet material 52 suitable for is provided. material,
For example, as shown and described herein as suitable for use in accordance with the present invention,
And methods of making and characterizing them are described in Cha 21 May 1996.
It is described in more detail in commonly assigned US Pat. No. 5,518,801 to ppell et al. The disclosure content of this patent is incorporated herein by reference.

Referring now to FIG. 2A, sheet 52 includes a “strainable network” of discrete regions. As used herein, the term "strainable network" refers to a region of a region that is capable of stretching to a required degree in a given direction and which provides the sheet material with an elastic-like behavior upon extension that is applied and subsequently released.
Refers to groups that are interconnected and correlated. The strainable network includes at least a first region 64 and a second region 66. The sheet material 52 has a first area 64 and a second area 64.
It includes a transition region 65 at the boundary between regions 66. Transition region 65 will exhibit a complex combination of behaviors of both the first and second regions. It will be appreciated that all embodiments of such sheet material suitable for use in accordance with the present invention have a transition region, which, by contrast, is such material
It is defined by the behavior of the sheet material in the area 64 and the second area 66. Therefore, since it does not depend on the combined behavior of the sheet material in the transition zone 65, the description that follows will relate to the behavior of the sheet material in the first and second zones only.

The sheet material 52 has a first surface 52a and an opposite second surface 52b.
In the preferred embodiment shown in FIG. 2A, the strainable network includes a plurality of first regions 64 and a plurality of second regions 66. The first region 64 has a first shaft 68 and a second shaft 69. Here, the first shaft 68 is preferably the second shaft 6.
Longer than 9. The first axis 68 of the first region 64 is substantially parallel to the longitudinal axis “L” of the sheet material 52. On the other hand, the second axis 69 is substantially parallel to the horizontal axis "T" of the sheet material 52. Preferably, the second axis of the first region, ie the width of the first region, is about 0.0.
It is from 1 inch to about 0.5 inch, more preferably from about 0.03 inch to about 0.25 inch. The second region 66 has a first shaft 70 and a second shaft 71.
The first axis 70 is substantially parallel to the longitudinal axis of the sheet material 52. On the other hand, the second axis 71 is substantially parallel to the horizontal axis of the sheet material 52. Preferably, the second axis of the second region,
That is, the width of the second region is about 0.01 inches to about 2.0 inches, more preferably about 0.125 inches to about 1.0 inches. In the preferred embodiment of FIG. 2A, the first region 64 and the second region 66 are substantially straight and extend continuously in a direction substantially parallel to the longitudinal axis of the sheet material 52. .

The first region 64 has an elastic modulus E1 and a cross-sectional area A1. The second region 66 has an elastic modulus E2 and a cross-sectional area A2.

In the illustrated embodiment, the sheet material 52 is “formed” such that the sheet material 52 exhibits a resistance force along an axis, and in the illustrated embodiment, the web longitudinal direction. The axis is substantially parallel to the longitudinal axis when subjected to an applied axial extension in a direction substantially parallel to the axis. As used herein, the term "forming" refers to the desired structure or geometry for a sheet material that substantially retains the desired structure or geometry when subjected to no externally applied extension or force. Refers to generation. The sheet material of the present invention comprises at least a first region and a second region.
Composed of areas. Here, the first area is visually different from the second area (visual area).
ly distinct). The term "visually different" as used herein means
Refers to features of the sheet material that can be readily discerned by the ordinary naked eye when the sheet material or an object containing the sheet material is normally used. As used herein, the term “surface path length” refers to the topography of the area in a direction substantially parallel to the axis.
Refers to the dimension along the surface. The method of determining the surface path length of each region is described above and incorporated into the contents of the present specification.
can be found in the Test Methods section of the US patent.

Methods for forming such materials useful in the present invention include matte plates (m
mating rolls or mating rolls
Embossing, thermoforming, high pressure hydraulic forming, or casting. Although all portions of the web 52 have been subjected to forming operations, the present invention is limited to only a portion thereof, for example as further detailed below,
It can also be carried out by forming only a part of the material including the bag body 20.

In the preferred embodiment shown in FIG. 2A, the first region 64 is substantially planar. That is, the material in the first region 64 remains substantially the same before and after the forming step that the web 52 undergoes. The second region 66 includes a plurality of raised rib-like elements 74.
including. The rib-like elements may be embossed or debossed,
Alternatively, they may be combined. The rib-like element 74 has a first axis or major axis 76 that is substantially parallel to the transverse axis of the web 52 and a second axis or minor axis 77 that is substantially parallel to the longitudinal axis of the web 52. The length of the rib-like element 74 parallel to the first axis 76 is at least equal to the length parallel to the second axis 77, and preferably longer. Preferably, the ratio of the first shaft 76 to the second shaft 77 is at least about 1: 1 or higher, more preferably at least about 2: 1 or higher.

The rib-like elements 74 in the second region 66 may be separated from each other by unformed zones. Preferably, the rib-like elements 74 are adjacent to one another and are separated by an unformed zone of less than 0.10 inches measured perpendicular to the longitudinal axis 76 of the rib-like elements 74,
More preferably, the rib-like elements 74 are in close proximity and have substantially no unformed areas between them.

The first area 64 and the second area 66 each have a “projection path length”. The term "projection path length" as used herein refers to the length of the shadow of the area formed by the collimated light. The projection path length of the first area 64 and the projection path length of the second area 66 are equal to each other.

The first area 64 is defined by the web 5 while the web is in an unstressed state.
2 has a surface path length L1 shorter than the surface path length L2 of the second region 66, measured topographically in a direction parallel to the vertical axis. Preferably, the surface path length of the second region 66 is at least about 15% longer than that of the first region 64, more preferably at least about 30% longer than that of the first region, and most preferably at least that of the first region. About 70% longer. Generally, before encountering a force wall, the second
The longer the surface path length of the area, the greater the elongation of the web. Suitable techniques for measuring the surface path length of such materials are described in the Chappell et al. Patent, supra, which is incorporated herein by reference.

The sheet material 52 exhibits a modified “Poisson lateral shrinkage effect”. It has a similar material composition and is substantially smaller than that of an otherwise identical base web. A method of measuring the Poisson lateral shrinkage effect of a material can be found in the Test Methods section of the Chappell et al. Patent, discussed above and incorporated herein into its content.
Preferably, the Poisson lateral shrinkage effect of a web suitable for use in the present invention is less than about 0.4 when the web undergoes an elongation of about 20%. Preferably, the web exhibits a Poisson lateral shrinkage effect of less than about 0.4 when subjected to an elongation of about 40, 50 or even 60%. Even more preferably, the Poisson lateral contraction effect is less than about 0.3 when the web undergoes 20, 40, 50 or 60% elongation.
The Poisson lateral shrinkage effect of such webs is determined by the amount of web material occupied by the first and second regions, respectively. As the area of sheet material occupied by the first region increases, so does the Poisson lateral shrinkage effect. In contrast,
As the area of sheet material occupied by the second region increases, the Poisson lateral shrinkage effect decreases. Preferably, the area fraction of the sheet material occupied by the first region is about 2% to about 90%, more preferably about 5% to about 50%.

Prior art sheet materials having at least one elastic material layer have a large Poisson lateral shrinkage effect. That is, when they grow in response to the applied force,
"Neck down". Materials useful according to the present invention may be properly designed even when the Poisson lateral shrinkage effect is substantially non-negligible.

In the sheet material 52, the direction of the applied axial extension D, indicated by arrow 80 in FIG. 2A, is substantially perpendicular to the first axis 76 of the rib-like element 74. The rib-like elements 74 extend flat in a direction substantially perpendicular to each first axis 76, or
Or it can be deformed geometrically and can be stretched within the web 52.

Referring now to FIG. 2B, the web of sheet material 52 undergoes a shorter surface path when subjected to an applied axial extension D, indicated by arrow 80 in FIG. 2B. The first region 64 with the length L1 provides most of the initial resistance force P1 to the applied elongation as a result of molecular-level deformation. At this stage, the second area 66
Rib-like element 74 at is undergoing geometric deformation or is extending flat and presents a small resistance to applied elongation. During the transition to the next stage, the rib-like elements 74 become aligned with the applied stretch (ie, become coplanar). That is, the second region shows a change from geometrical deformation to molecular-level deformation. This is the beginning of the power wall. Figure 2 (C
), The rib-like elements 74 of the second region 66 are substantially aligned (coplanar) with the plane of extension applied (ie, the second region reaches the limit of geometric deformation). ), It begins to resist further elongation due to molecular-level deformation. Second
Region 66 then provides a second resistance P2 as a result of the deformation at the molecular level, against further applied elongation. The resistance to elongation caused by both the molecular deformation of the first region 64 and the molecular deformation of the second region 66 is
The total resistance PT is greater than the resistance caused by the molecular deformation of the first region 64 and the geometric deformation of the second region 66.

When (L1 + D) is smaller than L2, the resistance force P1 is substantially larger than the resistance force P2. When (L1 + D) is less than L2, the first region produces an initial resistance force P1 that approximately satisfies the equation: P1 = (A1 * E1 * D) / L1. When (L1 + D) is greater than L2, the first and second regions have the equation: PT = (A1 * E1 * D) / L1 + (A2 * E2 * | L1 + D-L2 |) / L2
Which results in a mixed total resistance PT to the applied elongation D which approximately satisfies

The maximum elongation that occurs during the stage corresponding to FIGS. 2A and 2B before reaching the stage shown in FIG. 2C is the “effective stretch” of the formed web material. The effective stretch corresponds to the distance that the second region experiences geometric deformation. The range of effective elongation varies from about 10% to 100%, or more, depending mainly on the extent to which the surface path length L2 in the second region exceeds the surface path length L1 in the first region, and the composition of the base film. , Can be controlled. The term "effective elongation" is not intended to imply a limit to the elongation experienced by the web of the present invention when there are applications where elongation above effective elongation is desired.

When the sheet material undergoes applied elongation, the sheet material exhibits an elastic-like behavior such that it extends in the direction of applied elongation. Then, when the applied elongation is removed, the sheet material returns to a substantially tension-free state when not extended beyond the yield point. The sheet material can undergo multiple cycles of applied elongation without substantially losing its ability to recover. Thus, the web can return to a substantially tension-free state when the applied elongation is removed.

The sheet material can be easily and reversibly extended in the direction of the applied axial extension, ie substantially perpendicular to the first axis of the rib-like element, while the web material is It does not extend very easily in a direction substantially parallel to the first axis of the profile element.
The formation of the rib-like element requires that the rib-like element be deformed geometrically in a direction substantially perpendicular to the first or long axis of the rib-like element while requiring a substantial molecular level of deformation. The rib element extends in a direction substantially parallel to the first axis.

The magnitude of the applied force required to extend the web depends on the composition and cross-sectional area of the sheet material and the width and spacing of the first regions. The narrower first region and wider spacing require less extension force to achieve the desired elongation for a given composition and cross-sectional area. The first axis (ie, length) of the first region is preferably larger than the second axis (ie, width) of the first region, with a preferred length to width ratio of 5: 1 or greater.

The depth and frequency of the rib-like elements can also be varied to control the effective stretch of a web of sheet material suitable for use in accordance with the present invention. For a rib element of a given frequency, increasing the height or degree of formation imparted to the rib element increases the effective elongation. Similarly, increasing the frequency of the rib elements for a given height or degree of formation increases the effective elongation.

There are several functional properties that can be controlled through the application of the above materials to the flexible cover of the present invention. These functional properties are the resistance exerted by the sheet material against elongation and the effective elongation of the sheet material before encountering the force wall. The resistance exerted by the sheet material against the applied elongation is a function of the material (eg, composition, molecular structure and orientation, etc.) and cross-sectional area, and the percentage of the projected surface area of the sheet material occupied by the first region. is there. The higher the area coverage of the sheet material by the first region, the higher the resistance of the web to a given material composition and cross-sectional area against the applied elongation. The occupancy area of the sheet material by the first region is partially, but not entirely, determined by the width of the first region and the spacing between adjacent first regions.

The effective elongation of the web material is determined by the surface path length of the second region. The surface path length of the second region is determined at least in part by the depth of formation of the rib elements, the frequency of the rib elements, and the spacing of the rib elements, as measured perpendicular to the plane of the web material. . Generally, the longer the surface path length of the second region, the greater the effective elongation of the web material.

As described above with respect to FIGS. 2 (A), 2 (B) and 2 (C), the sheet material 52 initially exhibits a predetermined resistance to the elongation provided by the first region 64, On the other hand, the rib-like elements 74 in the second region 66 experience geometrical movement. Increased resistance to elongation is generally exhibited by the sheet material as a transition of the rib-like element to the plane of the first region of the material, followed by molecular level deformation. Therefore, FIG.
Sheet materials of the type shown in FIGS. 2A and 2B and 2C and described above and in the Chappel et al. Patent, which is incorporated herein by reference, are of the present invention. When formed on the cover, it provides the advantages of the present invention.

A further advantage realized by utilizing the above-described sheet materials that make up the flexible cover according to the present invention is the enhanced visual and tactile appeal of such materials. The polymer films commonly used to form such flexible covers are typically relatively thin in nature and often have a smooth, glossy surface finish. Although some manufacturers use a small amount of embossing or other texturing of the film surface, covers made of these materials still tend to present a slippery, thin, tactile impression. Thin materials, coupled with a substantially two-dimensional surface profile, also tend to give the consumer an excessive impression of thinness and perceived lack of durability for such flexible polymer covers.

In contrast, sheet materials useful according to the present invention, such as those shown in FIGS. 2 (A), 2 (B) and 2 (C), exhibit a three-dimensional cross-sectional shape and sheet materials are Is deformed from a predetermined plane of the sheet material (without being applied). This provides additional surface area for gripping and reduces the glare normally associated with a substantially planar and smooth surface. The three-dimensional rib-like elements also provide a "cushion-like" tactile sensation when gripping the cover, and also contribute to a desirable tactile impression that is symmetrical with conventional cover materials, providing a perception of thickness and durability. It also brings the improvement of. The additional feel reduces the noise associated with certain types of film material, which enhances the audible impression.

Suitable mechanical methods for forming a substrate into a web of sheet material suitable for use in the present invention are well known in the art and are described in Chap, supra.
Pell et al. and U.S. Pat. No. 5,650,214, issued July 22, 1997 in the name of Anderson et al. and assigned together. The disclosure content of these patents is incorporated herein by reference.

Another method of forming a substrate into a sheet material web suitable for use in the present invention is vacuum forming. An example of a vacuum forming process is disclosed in commonly assigned US Pat. No. 4,342,314 issued August 3, 1982 to Radel et al. Alternatively,
Formed webs of sheet material can be hydraulically formed according to the description of commonly assigned US Pat. No. 4,609,518 issued to Curro et al. On September 2, 1986. . The disclosure content of each of the above patents is incorporated herein by reference.

The forming method can be achieved in a static mode in which the individual parts of the base film are deformed one at a time. Alternatively, the forming method can be accomplished by intermittently contacting the moving web and using continuous, dynamic pressing to form the substrate into the formed web material of the present invention. These and other suitable methods for forming the web material of the present invention are more fully described in the Chappell et al. Patents mentioned above and incorporated herein by reference. The flexible cover may be composed of a formed sheet material, or it may be composed of a flexible cover and then subjected to a method for forming the sheet material.

Referring now to FIG. 3, sheet material 52 suitable for use in accordance with the present invention may use other patterns in the first and second regions. Sheet material 52 is shown in FIG. 3 in a substantially untensioned state. The sheet material 52 is
Two centerlines, a vertical centerline (hereinafter referred to as the axis, line, or direction "L"), and a transverse centerline, or lateral centerline (hereinafter referred to as the axis, line, or direction "L"). T
"). The horizontal centerline "T" is substantially perpendicular to the vertical centerline "L". Materials of the type shown in FIG. 3 are described in more detail in the Anderson et al. Patent, referenced above.

As described above with respect to FIGS. 2 (A), 2 (B) and 2 (C), the sheet material 52 comprises different regions of a “strainable network”. The strainable network includes a plurality of visually distinct first regions 60 and a plurality of second regions 66. The sheet material 52 is located at the boundary between the first region 60 and the second region 66 and is in the transition region 6
Including 5. The transitional region 65 represents a combined combination of behaviors of both the first and second regions as described above.

The sheet material 52 has a first surface (facing the viewer in FIG. 3) and an opposite second surface (not shown). In the preferred embodiment shown in FIG. 3, the strainable network comprises a plurality of first regions 60 and a plurality of second regions 66. A portion of the first region 60, shown generally as 61, is substantially linear and extends in the first direction. The remaining first region 60, shown schematically as 62, is substantially linear,
It extends in a second direction that is substantially perpendicular to the first direction. The first direction is preferably perpendicular to the second direction, but as long as the first regions 61 and 62 intersect each other, other angular relationships between the first and second directions may be suitable. is there.
Preferably, the angle between the first and second directions ranges from about 45 ° to about 135 °, with 90 ° being most preferred. The intersection of the first regions 61 and 62 forms the boundary indicated by the phantom line 63 in FIG. 3 and completely surrounds the second region 66.

Preferably, the width 68 of the first region 60 is about 0.01 inches to about 0.5 inches, more preferably about 0.03 inches to about 0.25 inches. However, other width dimensions for the first region 60 may also be suitable. First area 61
The second area has a square shape because and 62 are perpendicular to each other and are equally spaced apart. However, other shapes for the second regions 66 are suitable, this being the spacing between the first regions and / or the first regions 61 and 6.
This can be achieved by changing the alignment of the two with each other. Second
Region 66 has a first axis 70 and a second axis 71. The first axis 70 is substantially parallel to the longitudinal axis of the web material 52, while the second axis 71 is substantially parallel to the transverse axis of the web material 52. The first region 60 has a modulus of elasticity E1 and a cross-sectional area A1. The second region 66 has an elastic modulus E2 and a cross-sectional area A2.

In the embodiment shown in FIG. 3, the first region 60 is substantially flat. That is, the material in the first region 60 is in substantially the same state before and after the forming process that the web 52 undergoes. The second region 66 includes a plurality of raised rib-like elements 74. The rib-like elements 74 may be embossed, debossed, or a combination thereof. The rib-like element 74 has a first axis or major axis 76 that is substantially parallel to the longitudinal axis of the web 52 and a second axis or minor axis 77 that is substantially parallel to the transverse axis of the web 52.

The rib-like elements 74 of the second region 66 may be separated from each other by essentially unembossed or debossed or unformed zones formed as spacing zones. Preferably, the rib-like elements 74 are adjacent to one another and are separated by an unformed zone of less than 0.10 inches measured perpendicular to the longitudinal axis 76 of the rib-like elements 74. More preferably, the rib-like elements 74 are in close proximity and have essentially no unformed zones between them.

Each of the first region 60 and the second region 66 has a “projection path length”. The term "projection path length" as used herein refers to the length of the shadow of the area formed by the collimated light. The projection path length of the first area 60 and the projection path length of the second area 66 are equal to each other.

The first region 60 has a surface path length L1 shorter than the surface path length L2 of the second area 66. These shall be topographically measured in parallel directions when the web is in an unstressed state. Preferably, the surface path length of the second region 66 is at least about 15% longer than that of the first region 60, more preferably at least about 30% longer than that of the first region, and most preferably that of the first region. At least about 70% longer than one. In general, the longer the surface path length of the second region, the greater the stretch of the web before encountering the force wall.

For the sheet material 52, the direction of the applied axial extension D, indicated by arrow 80 in FIG. 3, is substantially perpendicular to the first axis 76 of the rib-like element 74. This is due to the fact that the rib-like elements 74 can extend flat in a direction substantially perpendicular to their respective first axes 76 or can be geometrically deformed and stretchable within the web 52. to cause.

Referring now to FIG. 4, when the web 52 undergoes an applied axial extension D, indicated by arrow 80 in FIG. 4, a first region 60 having a shorter surface path length L1.
Provides the majority of the initial resistance force P1 to the applied elongation, which corresponds to Stage I as a result of molecular deformation. During Stage I, the rib-like elements 74 in the second region 66 are undergoing geometric deformation or are extending flat and are minimal to the applied extension. Indicates resistance. Further, the shape of the second region 66 changes as a result of the variation in the mesh structure formed by the intersection of the first regions 61 and 62. Thus, when the web 52 is subjected to an applied stretch, the first regions 61 and 62 experience geometric deformation or bending, resulting in a change in the shape of the second region 66. The second region extends or extends in a direction parallel to the direction of applied elongation and collapses or contracts in a direction perpendicular to the direction of applied elongation.

In addition to the elastic-like properties described above, sheet materials of the type shown in FIGS. 3 and 4 are softer, provide a more cloth-like feel and appearance, and are quieter in use.

Various compositions suitable for forming the flexible cover of the present invention include polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyethylene (PE), polypropylene (PP), aluminum foil, coated. • Paper (such as paraffin paper) and uncoated paper, substantially impermeable materials such as coated nonwovens, and primarily original materials such as scrims, meshes, wovens, nonwovens, or perforated or porous films. It has a two-dimensional structure or is formed into a three-dimensional structure and includes a substantially permeable material. Such materials may comprise a single composition or layer, or may be a composite structure of multiple materials.

If the desired sheet material is manufactured in any desired and suitable manner and comprises all or part of these materials for utilization in the cover body, the cover may be in any known suitable manner, for example , Would be constructed in a well known manner to make such a cover a commercially useful form. The various components or elements of the cover can be bonded to themselves or to each other using heat sealing, mechanical sealing, or adhesive sealing techniques. Further, the cover body can be thermoformed, blow molded, or otherwise formed to form the cover body from a material web or sheet, rather than relying on folding and gluing techniques.

While particular embodiments of the present invention have been described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. . It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

[Brief description of drawings]

[Figure 1]   FIG. 3 is a plan view of an exemplary flexible cover according to the present invention.

FIG. 2A is a partial perspective view of a polymeric film material comprising the flexible cover of the present invention in a substantially untensioned state, and FIG. 2B is a partially untensioned view. FIG. 3C is a partial perspective view of a polymeric film material comprising a flexible cover according to the present invention in a tensioned state, FIG. Partial perspective view.

[Figure 3]   FIG. 6 is a plan view of another embodiment of a sheet material useful in the present invention.

4 is a plan view of the polymer web material of FIG. 3 in a partially tensioned state, similar to the state of FIG. 2 (B).

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, MZ, SD, SL, SZ, TZ, UG , ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, C N, CR, CU, CZ, DE, DK, DM, EE, ES , FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, K R, KZ, LC, LK, LR, LS, LT, LU, LV , MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, S I, SK, SL, TJ, TM, TR, TT, TZ, UA , UG, UZ, VN, YU, ZA, ZW (72) Inventor Berg, Charles John Jr.             45215 Wa, Ohio, United States             Ioming, Hillcrest Drive             208 (72) Inventor Lodge, Richard Worthington             45251 Shi, Ohio, United States             Nincinnati, Stone Quarry Court             11978 (72) Inventor Cooper, John Thomas             45069 U, Ohio, United States             Est Chester, Taragon Court             7333 (72) Inventor Jackson, Beverly Julian             45013 Ha, Ohio, United States             Milton, East Fairway Dora             Eve 167 (72) Inventor Happ, Matthew Todd             45241, Ohio, United States             Yaronville, Timber Ridge Lane               11624, Apartment number 3 (72) Inventor Mayer, Eric Walter             45215 Wa, Ohio, United States             Ioming, Worthington Avenue             27 (72) Inventor Baggot, Stephen John             45242, Ohio, United States             Lou Ash, Catarpa Creek             Drive 5140 (72) Inventor Andes, William Scott             45502 Su, Ohio, United States             Pullingfield, Mirror Road             3585 F term (reference) 3E037 AA20 BA10 BC01                 3E066 AA24 CA01 DB01 JA23 NA21                 3E086 AB01 AD28 BA02 BA04 BA14                       BA15 BA18 BA19 BB66 BB84                       CA33

Claims (10)

[Claims] 1. A flexible cover characterized by at least one sheet of flexible sheet material assembled to form a container having a perimeter and an open portion, said flexible cover comprising: The cover is extensible in response to a force exerted by the article, item or material, the cover is placed over the article, item or material and the cover is placed therein, A flexible cover that increases the volume of the cover to accommodate an item or material. 2. The flexible cover has an elasticized edge.
The flexible cover according to. 3. The sheet material includes first and second regions of the same material composition, the first and second regions of the sheet material being subjected to an applied elongation along at least one axis. 3. The flexible cover of claim 1 or 2, wherein the region experiences a substantially molecular deformation and the second region initially experiences a substantially geometric deformation. 4. The flexible cover according to claim 3, wherein the first region and the second region are visually different from each other. 5. The flexible cover according to claim 3 or 4, wherein the second region comprises a plurality of raised rib-like elements. 6. The first region is substantially free of the rib-like elements.
The flexible cover according to any one of items 1 to 5. 7. The sheet material when subjected to an applied extension in a direction parallel to at least one axis in response to an externally applied force on the flexible cover when formed into a closed container. Shows at least two specifically different stages of resistance to an applied axial extension along said at least one axis, said sheet material comprising a strain comprising at least two visually distinct regions. A possible network is provided, one of these regions being provided before the remaining substantial part of these regions develops a specific resistance to said applied axial elongation.
Is configured to exhibit a resistance in response to the applied axial extension in a direction parallel to the axis, at least one of the regions being while the sheet material is in an untensioned state. Has a surface path length that is longer than the remaining surface path length of the area, measured parallel to the axis at, and the area exhibiting the longer surface path length has one or more rib-like elements. The sheet material is added until the elongation of the sheet material is large enough to include a substantial portion of the region having the longer surface path length to lie in the plane of the applied axial elongation. Exhibits a first resistance to elongation, the sheet material exhibits a second resistance to further axial elongation, and the sheet material exhibits a total resistance greater than the resistance of the first region. Claims 1 to 6 The flexible cover according to item 1 or. 8. The sheet when subjected to an applied axial extension D along at least one axis in response to an externally applied force to the flexible cover when formed into a closed container. The material exhibits at least two stages of resistance to the applied axial extension along the at least one axis, the sheet material comprising a visually dissimilar region of distortable network; The strainable network comprises at least a first region and a second region, the first region being measured parallel to the axis while the sheet material is in an unstressed state. A second surface path length L2, the second region having a second surface path length L2 measured parallel to the axis while the sheet material is in an unstressed state; 1 surface path length L1 is Shorter than the second surface path length L2, the first region itself produces a resistance force P1 in response to the applied axial extension D, and the second region causes the applied axial extension D to occur. The resistance force P2 is generated by itself according to, and when (L1 + D) is smaller than L2, the resistance force P1 is substantially larger than the resistance force P2. Flexible cover. 9. The sheet material exhibits elastic-like behavior along at least one axis, the sheet material having at least a first region and a second region, the first region and the second region being the same. The material composition, each having a projected path length that is not tensioned, such that when formed into a closed container, the web material is responsive to an external force applied to the flexible cover. The first region undergoes a substantially molecular level deformation when subjected to an applied elongation in a direction substantially parallel to the axis and the second region is initially substantially geometric. 9. The first region and the second region substantially return to their respective untensioned projection path lengths when they experience different deformations and the applied elongation is released. The flexible cover according to claim 1. 10. The sheet material includes a plurality of first regions and a plurality of second regions having the same material composition, a part of the first regions extending in a first direction, and the first region. The remainder of one region extends in a direction perpendicular to the first direction and intersects with each other, and the first region forms a boundary that completely surrounds the second region.
The flexible cover according to any one of 7, 8 and 9.