An intercellular structure and a battery module including the intercellular structure, and a method of assembling the battery module are provided. The intercellular structure includes a honeycomb structure including a plurality of hexagonal cells. Each of the plurality of hexagonal cells has an open-ended top and an open-ended bottom and is configured to be arranged around a middle section of one of a plurality of battery cells. The battery module includes a plurality of battery cells arranged in a predetermined pattern and the honeycomb structure including the plurality of hexagonal cells.

An improved expandable slit-sheet stock material is configured to aid in temporarily restricting opening of a plurality of slits of the slit-sheet stock material, such as during winding of the unexpanded stock material or during expansion of the stock material. Each slit of the plurality of slits includes one or more un-slit reinforcement portions, such as reinforcement ties, extending fully between opposite longitudinal sides of the slit, and disposed between opposed transverse endpoints of the slit. The reinforcement ties minimize or prevent tearing of the stock material during the winding or expansion. A dunnage conversion system for expanding the slit-sheet stock material includes an expander having a pair of opposed rollers. The rollers engage the stock material to effect breaking of the un-slit reinforcement portions and expansion of the slit-sheet stock material.

A three-dimensional auxetic structure, comprising a plurality of adjoining hollow cells, each hollow cell having cell walls and a transversal cross section of the plurality hollow cells following a two-dimensional auxetic pattern, each cell wall comprising folding lines parallel to a plane containing the auxetic pattern such that peaks and valleys are defined in the cell walls and the cell walls being foldable along the folding lines.

An extensible slit sheet paper product is produced having an expandable slit pattern that forms open cells upon expansion of the paper product. The paper product is an extensible paper having an extensibility in the range from 1-9% in the machine direction and 1-5% in the cross direction. The expansion produces an array of hexagonal cells. The expanded extensible paper can be used to wrap an object for shipping by wrapping and cushioning the object in the expanded slit sheet material. The extensible, expandable slit sheet paper can be wrapped around itself to produce a void fill product.

In the preferred embodiments, the present invention provides substantially improved slit sheet cushioning products by advantageously combining novel paper properties with novel slit patterns for improved features and characteristics. In some illustrative and non-limiting example embodiments, cushioning products of the present invention can include, e.g., a novel slit sheet material in combination with extensible paper employed as, e.g., a cushioning pad or as cushioning within an envelope product, wherein the cushioning product can be substantially more resilient, but, yet, e.g., thinner for better utilization of space.

In the preferred embodiments, the present invention provides substantially improved slit sheet cushioning products by advantageously combining novel paper properties with novel slit patterns for improved features and characteristics. In some illustrative and non-limiting example embodiments, cushioning products of the present invention can include, e.g., a novel slit sheet material in combination with extensible paper employed as, e.g., a cushioning pad or as cushioning within an envelope product, wherein the cushioning product can be substantially more resilient, but, yet, e.g., thinner for better utilization of space.

An extensible slit sheet paper product is produced having an expandable slit pattern that forms open cells upon expansion of the paper product. The paper product is an extensible paper having an extensibility in the range from 1-9% in the machine direction and 1-5% in the cross direction. The expansion produces an array of hexagonal cells. The expanded extensible paper can be used to wrap an object for shipping by wrapping and cushioning the object in the expanded slit sheet material. The extensible, expandable slit sheet paper can be wrapped around itself to produce a void fill product.

A method of forming a structural honeycomb includes cutting and folding a substrate sheet according to predetermined cutting and folding patterns and fold angles that cause the sheet to form a honeycomb having cells that each have at least one face abutting, or nearly abutting, the face of another cell. The honeycomb is then stabilized by joining abutting, or nearly abutting, faces to hold the honeycomb together. The honeycomb may have a prespecified three-dimensional shape. The folding pattern may include corrugation, canted corrugation, or zig-zag folds. Joining may employ fixed and/or reversible joinery, including slotted cross section, tabbed strip, angled strip, integral skin, sewn, or laced. At least some folds may be partially-closed to create bends and twists in the honeycomb structure. Some surfaces of the honeycomb may be covered with a skin or face sheet. The substrate sheet may have flexible electronic traces.

An extensible slit sheet paper product is produced having an expandable slit pattern that forms open cells upon expansion of the paper product. The paper product is an extensible paper having an extensibility in the range from 1-9% in the machine direction and 1-5% in the cross direction. The expansion produces an array of hexagonal cells. The expanded extensible paper can be used to wrap an object for shipping by wrapping and cushioning the object in the expanded slit sheet material. The extensible, expandable slit sheet paper can be wrapped around itself to produce a void fill product.

In the preferred embodiments, the present invention provides substantially improved slit sheet cushioning products by advantageously combining novel paper properties with novel slit patterns for improved features and characteristics. In some illustrative and non-limiting example embodiments, cushioning products of the present invention can include, e.g., a novel slit sheet material in combination with extensible paper employed as, e.g., a cushioning pad or as cushioning within an envelope product, wherein the cushioning product can be substantially more resilient, but, yet, e.g., thinner for better utilization of space.