Propylene Alpha-Olefin Copolymer Liners for Flex-Crack Resistance

Solution Overview

Problem

Bulk container liners are prone to flex-cracking and leakage due to stress from product weight and movement during transportation, especially at the gas-liquid interface, and existing solutions like dunnage increase costs and labor without fully addressing the issue.

Innovation Solution

A liner design featuring a sidewall with an exterior and interior ply, where the interior ply is made of propylene alpha-olefin copolymer with a density range of 0.865 g/cm3 to 0.900 g/cm3, providing improved flex-crack resistance without the need for dunnage, and optionally including intermediate plies and a polyolefin-silicone copolymer for enhanced stress dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dunnage is used to reduce flex-cracking, then liner reliability is improved, but manufacturing cost and labor cost increase

Engineering Contradiction:

Improveliner reliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the material parameters of the liner by incorporating propylene alpha-olefin copolymer with specific density (0.865-0.900 g/cm³) and composition (5-50% by weight), which fundamentally alters the liner's mechanical properties to provide inherent flex-crack resistance without requiring additional dunnage materials

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The liner material itself provides the flex-crack resistance function that previously required separate dunnage materials. The propylene alpha-olefin copolymer composition enables the liner to self-absorb and dissipate stress, eliminating the need for external protective materials and reducing both material and labor costs

Inventive Principle:

Principle #25Self-service

2Reliability

If dunnage is used to reduce flex-cracking, then liner reliability is improved, but labor time increases

Engineering Contradiction:

Improveliner reliabilityVSAvoidlabor time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The liner material itself provides the flex-crack resistance function that previously required separate dunnage materials. The propylene alpha-olefin copolymer composition enables the liner to self-absorb and dissipate stress, eliminating the need for external protective materials and reducing both material and labor costs

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent extracts and eliminates the dunnage component from the packaging system by incorporating its protective function directly into the liner material composition, thereby removing the additional step of placing dunnage during assembly

Inventive Principle:

Principle #2Taking out (Extraction)

3Strength

If liner thickness is increased to resist flex-cracking, then strength is improved, but weight increases

Engineering Contradiction:

Improveflex-crack resistanceVSAvoidliner weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent changes the material parameters of the liner by incorporating propylene alpha-olefin copolymer with specific density (0.865-0.900 g/cm³) and composition (5-50% by weight), which fundamentally alters the liner's mechanical properties to provide inherent flex-crack resistance without requiring additional dunnage materials

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining propylene alpha-olefin copolymer with other polymers (such as polyethylene) to create a multilayer structure that provides enhanced flex-crack resistance. This composite approach allows optimization of both strength and weight by selecting materials with appropriate density and mechanical properties

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS20230166486A1Liners for bulk containers

Publication Date: 2023.06.01 AMCOR FLEXIBLES NORTH AMERICA INC

AI summary

Described are liners for bulk containers that are abuse resistant The liners include at least one sidewall that includes an exterior ply and an interior ply. The interior ply includes a propylene alpha-olefin copolymer that includes a density in a range from 0.865 g/cm3 to 0.900 g/cm3, The interior ply includes the propylene alpha-olefin copolymer in an amount from 5% to 50% by weight of the interior ply.