Polyethylene Composition for BOPE Tenter Frame Processing

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Solution Overview

Problem

Existing polyethylene raw materials are unsuitable for tenter frame processes, resulting in poor film forming performance and ease of film fracture when producing biaxially oriented polyethylene (BOPE) films.

Innovation Solution

Development of novel polyethylene compositions with specific molecular weight ranges and ratios, including ethylene/α-olefin copolymerized linear low density polyethylene, optimized for tenter frame processes to achieve improved film forming performance and mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If known polyethylene raw materials are used in tenter frame processes, then the process can be performed, but the film forming performance is poor and film fracture occurs easily

Engineering Contradiction:

Improvefilm forming performanceVSAvoidfilm fracture resistance

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by precisely controlling the molecular weight distribution parameters (Mw: 100,000-200,000 g/mol, Mw/Mn: 4.0-9.0, Mz/Mw: 4.0-7.0, Mz+1/Mw: 4.5-13.5) of the polyethylene composition to enable successful tenter frame processing without film fracture while achieving excellent film forming performance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining ethylene/α-olefin copolymerized linear low density polyethylene with specific molecular weight distribution characteristics to create a composition that simultaneously provides good film forming performance and fracture resistance in tenter frame processes

Inventive Principle:

Principle #40Composite materials

2Productivity

If existing polyethylene raw materials are used, then production can proceed, but stretching speed and stretch ratio are very low

Engineering Contradiction:

Improvestretching speed and stretch ratioVSAvoidfilm forming performance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent achieves high productivity by optimizing the molecular weight parameters of the polyethylene composition (Mw: 100,000-200,000 g/mol, Mw/Mn: 4.0-9.0), which enables large stretch ratios and high stretching speeds in the tenter frame process while maintaining excellent film forming performance

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If polyethylene raw materials are used in tenter frame processes, then film production is possible, but the difficulty of film stretching processing is large

Engineering Contradiction:

Improvefilm stretching processing difficultyVSAvoidfilm forming performance

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent reduces film stretching processing difficulty by carefully controlling the molecular weight distribution parameters (Mw/Mn: 4.0-9.0, Mz/Mw: 4.0-7.0, Mz+1/Mw: 4.5-13.5) of the polyethylene composition, which improves processability and reduces the difficulty of film stretching while maintaining excellent film forming performance

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9988505B2Polyethylene compositions and films formed therefrom

Publication Date: 2018.06.05 CHINA PETROLEUM & CHEMICAL CORP

AI summary

A polyethylene composition comprising an ethylene/α-olefin copolymerized linear low density polyethylene, wherein the polyethylene composition has a Mw of from 100,000 g/mol to 200,000 g/mol, a Mw/Mn of from 4.0 to 9.0, a Mz/Mw of from 4.0 to 7.0, and a Mz+1/Mw of from 4.5 to 13.5, is provided. A film formed of the polyethylene composition is also provided.