Multilayer Nonwoven Web Reducing Necking via Local Quality

Solution Overview

Problem

Nonwoven webs made from certain polyolefin blends, such as polypropylene with a propylene copolymer and a softness enhancer additive, are prone to unacceptable levels of necking, which affects their cost and processability, particularly when subjected to high tension in the machine direction.

Innovation Solution

A nonwoven web comprising at least two fibrous layers with different compositions, where one layer includes fibers made of a blend of polypropylene with a propylene copolymer and a softness enhancer additive, and the second layer has distinct mechanical properties, reducing necking by incorporating a polypropylene homopolymer with a lower propylene copolymer content.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a nonwoven web is made from a blend of polypropylene with propylene copolymer and softness enhancer additive, then the tactile softness is improved, but the necking under tension increases to unacceptable levels

Engineering Contradiction:

Improvetactile softnessVSAvoidnecking

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating a multilayer structure where different layers have different compositions and properties. The first layer contains the softness-enhancing blend (polypropylene, propylene copolymer, and softness enhancer additive), while the second layer uses a different composition to provide mechanical stability and reduce necking. This allows each layer to perform its specific function optimally without compromising the other.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple polymeric components in a multilayer nonwoven web. The first layer comprises a blend of polypropylene, propylene copolymer, and softness enhancer additive, while the second layer has a different composition. This composite structure achieves both tactile softness and reduced necking by distributing functional requirements across different material layers.

Inventive Principle:

Principle #40Composite materials

2Productivity

If high tension is applied in the machine direction during web transport, then the web can be unwound and processed, but excessive necking occurs reducing cross-direction length

Engineering Contradiction:

Improveweb transport efficiencyVSAvoidcross-direction length

Core Design Contradiction:

ProductivityVSLength of moving object

Solution Approach 1:

The patent applies local quality by creating a multilayer structure where different layers have different compositions and properties. The first layer contains the softness-enhancing blend (polypropylene, propylene copolymer, and softness enhancer additive), while the second layer uses a different composition to provide mechanical stability and reduce necking. This allows each layer to perform its specific function optimally without compromising the other.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple polymeric components in a multilayer nonwoven web. The first layer comprises a blend of polypropylene, propylene copolymer, and softness enhancer additive, while the second layer has a different composition. This composite structure achieves both tactile softness and reduced necking by distributing functional requirements across different material layers.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentEP2916792B1Article(s) with soft nonwoven web

Publication Date: 2017.09.20 PROCTER & GAMBLE CO

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Figure 4A

AI summary

A product that includes a soft nonwoven web is disclosed. The nonwoven web includes a first fibrous layer made of a first composition and a second fibrous layer made of a second composition. The second composition is different from the first composition.