Hybrid Paper-Polymer Mailing Sack for Kerbside Recyclability

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Solution Overview

Problem

Current mailing sacks are not recyclable, require substantial environmental and financial commitments, and lead to inefficient packaging and transportation due to their materials and production processes, resulting in excessive waste and repetitive strain injuries during manual filling and closure.

Innovation Solution

A biodegradable hybrid mailing sack made from recycled paper and extruded or laminated polymers, allowing for heat-sealable, lightweight, and malleable properties while being kerbside recyclable, with a design that enables flexible production of various sack options on a single machine, reducing material volume and environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional plastic bubble wrap lining is used in padded mailing sacks, then durability and protection are improved, but recyclability deteriorates as materials cannot be manually separated

Engineering Contradiction:
ImprovedurabilityVSAvoidrecyclability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The mailing sack is divided into separable components: a paper-based outer sack and an inner pouch containing the bubble wrap lining. This segmentation allows the paper sack to be recycled through kerbside collection while the protective inner pouch can be removed and disposed of separately, resolving the contradiction between durability and recyclability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An inner pouch acts as an intermediary element that provides the protective function of bubble wrap while being contained within a recyclable paper sack. The inner pouch can be easily removed and disposed of, allowing the outer paper sack to be recycled independently, thus mediating between the need for protection and recyclability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If sustainable paper-based materials are used for mailing sacks, then environmental sustainability is improved, but cost increases significantly compared to plastic-based options

Engineering Contradiction:
Improveenvironmental sustainabilityVSAvoidcost
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The mailing sack uses a composite structure combining paper-based outer sack with an inner pouch containing plastic bubble wrap. This composite approach allows the majority of the sack (paper portion) to be sustainable and recyclable, while using minimal plastic only where protective function is needed, thus improving sustainability without proportionally increasing cost.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Instead of making the entire mailing sack from expensive sustainable materials, the invention applies sustainable paper-based materials only to the outer sack structure, while using conventional plastic bubble wrap only in the inner pouch where protection is critically needed. This local application of quality reduces overall cost while maintaining environmental benefits.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If pre-made fixed size padded mailers are supplied to production locations, then ease of use is improved, but transportation efficiency deteriorates due to substantial costs of transporting trapped air

Engineering Contradiction:
Improveease of useVSAvoidtransportation efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The mailing sack design allows for variable sizing and configuration to match different product dimensions. The sack can be adjusted and filled to minimize empty space, converting the static pre-made fixed-size approach into a dynamic adaptable system that optimizes space utilization and reduces transportation waste.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mailing sack is designed as a universal format that can accommodate various product sizes and types by adjusting the filling process. This multi-functional design eliminates the need for multiple pre-made fixed-size mailers, allowing a single sack type to serve multiple purposes and reduce transportation inefficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If manual filling and closure processes are used for e-commerce mailers, then flexibility in handling various products is improved, but worker health deteriorates due to repetitive strain injury

Engineering Contradiction:
ImproveflexibilityVSAvoidrepetitive strain injury
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The mailing sack design incorporates features that enable automated or semi-automated filling and sealing processes. The sack structure is designed to work with automated equipment, allowing machines to perform the repetitive opening, filling, and closure operations, thereby eliminating manual repetitive strain while maintaining flexibility through programmable parameters.

Inventive Principle:
Principle #25Self-service

5Adaptability or versatility

If multiple different mailer sizes and formats are required for various product types, then product optimization is improved, but equipment complexity increases as e-tailers require multiple production machines

Engineering Contradiction:
Improveproduct optimizationVSAvoidequipment complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mailing sack is designed as a universal format that can be produced on a single machine and adapted to accommodate various product sizes and types. This multi-functional design allows one production line to replace multiple specialized machines, reducing equipment complexity while maintaining the ability to optimize packaging for different products.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The mailing sack production system uses adjustable parameters (size, shape, filling density) to create optimized packaging for different products. By changing parameters rather than using different machine types, the system achieves product optimization without increasing equipment complexity.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The hybrid material allows for the production of sustainable, recyclable, and cost-effective mailing sacks that minimize packaging volume, reduce waste, and prevent repetitive strain injuries, enabling optimal protection and efficient e-commerce logistics.

Implementation Method 1

a layer of paper and a film of an extruded or laminated polymer

Methodology Applied
Scientific EffectHeat sealing:

Implementation Method 2

said polymer is biodegradable

Methodology Applied
Scientific EffectBiodegradation: Decomposition (biological)

Data Source

PatentEP4232373B1Sack for mailing or dunnage and method for producing the same
Publication Date: 2024.08.21 DS SMITH PLC
  • EP4232373B1 patent drawingFigure 1~2
  • EP4232373B1 patent drawingFigure 3~4
  • EP4232373B1 patent drawingFigure 5

AI summary

A sack (10) for mailing at least one item (12) or for dunnage is formed by two facing panels sealed along the perimeter, wherein each panel is at least one-ply and wherein said ply includes a layer (18) of paper having a grammage 35 to 450 g/m2 and a film (20) of an extruded or laminated polymer covering one face of said layer (18) of paper.