Interfolded Napkin Stack Layout for Softness and Dispenser Fit

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Solution Overview

Problem

Interfolded paper napkins with single folds have high basis weight to achieve absorbency, resulting in low softness and drape properties, while multiple folds lead to elongated shapes and dispensing issues, and there is a need for cost-effective napkins that fit standard dispensers without compromising quality or durability.

Innovation Solution

A rectangular stack of interfolded napkins with alternating first and second folds, dividing each napkin into four panels, where the smaller part is placed outside and the larger part inside, allowing for even bulk distribution and reduced fiber usage, enabling more napkins in a standard package size with improved softness and drape properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If single fold is used to achieve simplicity and fit in dispenser, then dispensability is improved, but absorbency requires higher basis weight which reduces softness and drape properties

Engineering Contradiction:
ImprovedispensabilityVSAvoidbasis weight
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The napkin is divided into multiple panels through multiple folds, allowing the same absorbent area to be distributed across more segments. This enables lower basis weight while maintaining total absorbency, as the absorbent capacity is spread across multiple folded layers rather than requiring high weight in a single layer.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from single-fold to multiple-fold configurations, adding dimensional complexity to the folding pattern. This creates a multi-layered stacked arrangement that increases surface area and absorbency distribution without increasing basis weight, thereby improving softness and drape while maintaining dispensability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Quantity of substance

If multiple parallel folds are used to increase absorbency, then absorbency is improved, but the napkin becomes elongated which causes dispensing issues

Engineering Contradiction:
ImproveabsorbencyVSAvoidelongated shape
Core Design Contradiction:
Quantity of substanceVSShape

Solution Approach 1:

The invention uses asymmetric fold patterns where folds are positioned at different locations rather than evenly distributed. This creates a compact stacked shape that prevents elongation while maintaining multiple panels for adequate absorbency. The asymmetric arrangement allows panels of varying sizes to interlock in a way that creates a balanced, non-elongated profile.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The multiple folded panels are arranged in a nested stacked configuration where smaller panels are positioned within or between larger panels. This nesting arrangement compacts the overall shape, preventing elongation while maintaining the absorbent surface area provided by multiple panels.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Quantity of substance

If higher basis weight is used to achieve absorbency in single-fold napkins, then absorbency is improved, but softness and drape properties deteriorate

Engineering Contradiction:
ImproveabsorbencyVSAvoidsoftness and drape properties
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

By segmenting the napkin into multiple folded panels, the invention achieves distributed absorbency across the structure. This allows the use of lower basis weight material while maintaining total absorbent capacity, thereby preserving softness and drape properties that would otherwise be compromised by high-weight single-fold designs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the structural parameters from single-fold to multiple-fold configurations, altering how absorbency is achieved. Instead of relying on high basis weight, the system uses increased panel count and folded surface area, thereby maintaining material softness and drape while achieving adequate absorbency through geometric multiplication rather than mass increase.

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If cost reduction is pursued by using lighter napkins, then manufacturing cost is improved, but dispenser fit and durability are compromised

Engineering Contradiction:
Improvemanufacturing costVSAvoiddispenser fit and durability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The multi-panel folded structure provides inherent structural integrity through its segmented design. The multiple folds create interlocking panels that reinforce each other, maintaining durability and dispenser fit even with lighter basis weight materials. This segmentation allows cost reduction through lighter material while the folded structure itself provides the mechanical strength needed for reliable dispenser operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention creates a composite structure through multiple folded layers and panels that work together to provide both lightness and strength. The layered configuration allows lighter materials to achieve the same structural performance as heavier single-layer napkins, enabling cost reduction while maintaining reliability for dispenser fit and durability.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2797475B1Interfolded napkins and method for interfolding napkins
Publication Date: 2016.11.30 SCA HYGIENE PRODUCTS AB
  • EP2797475B1 patent drawingFigure 1~2
  • EP2797475B1 patent drawingFigure 3~4
  • EP2797475B1 patent drawingFigure 5~6

AI summary

The invention relates to a rectangular stack (40) of interfolded rectangular napkins (10) comprising a plurality of napkins (50, 80), each napkin (10) in the stack comprising a first fold (28) in a first direction, and a second fold (29) in a second direction perpendicular to the first direction. The first fold (28) divides the napkin (10) into a smaller part (30) and a larger part (31), wherein the area of the smaller part (30) is between 1/5 and 1/2 of the area of the larger part (31) and with the smaller part (30) of the napkin (10) placed on the outside of the folded napkin (10). The napkins (10) are arranged in the stack (40) with the first folds (28) arranged in an alternating sequence along opposing parallel sides of the stack (40) such that each napkin (10) is arranged with the first fold (28) opposite the first fold (28) of any adjacent napkin (10) in the stack (40).