Ethylene-CO Copolymer Adhesion at High Line Speeds
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Solution Overview
Problem
Conventional polymers used in extrusion coating exhibit unacceptable fiber tear adhesion at higher line speeds due to reduced oxidation time of molten polymer before contact with paper, leading to inferior adhesion between polymer and paper substrates.
Innovation Solution
Development of an ethylene-based polymer formed through high-pressure free-radical polymerization with specific properties, including CO content from greater than 0 to less than 10 weight percent and a melt index from 3 to 30 g/10 min, which provides improved adhesion at higher line speeds and lower melt temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional polymers are used in extrusion coating at higher line speeds, then productivity is improved, but adhesion to paper substrates deteriorates due to reduced oxidation time
Solution Approach 1:
The patent changes the chemical composition parameters of the polymer by incorporating carbon monoxide (0.1-10 wt%) and other comonomers (1-20 wt%) into the ethylene-based polymer structure. This compositional modification alters the polymer's oxidation behavior and adhesion properties, enabling it to maintain good fiber tear adhesion even at higher line speeds where conventional polymers would fail.
2Productivity
If higher line speeds are used to increase productivity, then manufacturing efficiency is improved, but fiber tear adhesion becomes unacceptable
Solution Approach 1:
The patent modifies the polymer's chemical structure by incorporating specific amounts of carbon monoxide (0.1-10 wt%) and comonomers (1-20 wt%), which changes the oxidation kinetics and adhesion characteristics. This allows the polymer to achieve acceptable fiber tear adhesion at higher line speeds, resolving the conflict between manufacturing efficiency and adhesion quality.
3Reliability
If oxidation time is increased to improve adhesion, then adhesion performance is improved, but processing time increases reducing productivity
Solution Approach 1:
The patent changes the chemical composition of the polymer to include carbon monoxide (0.1-10 wt%) and comonomers (1-20 wt%), which fundamentally alters the oxidation mechanism. This allows the polymer to achieve good adhesion performance without requiring prolonged oxidation time, thus maintaining high productivity while improving adhesion.
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 ethylene-based polymer achieves enhanced adhesion to paper substrates, passing fiber tear adhesion tests at higher temperatures and supporting the use of ethylene-based polymers in high-speed extrusion coating applications with improved performance compared to conventional LDPE or LLDPE.
Implementation Method 1
formed from a high pressure, free-radical polymerization
Data Source
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AI summary
The present invention relates to a composition comprising an ethylene-based polymer, formed from a high pressure, free-radical polymerization, and wherein the ethylene-based polymer has the following properties: a) a CO content from "greater than 0" to less than 10 weight percent CO (carbon monoxide), based on the weight of the polymer; and b) a melt index (I2) from 3 to 30 g/10 min, wherein the ethylene-based polymer has a melting point, Tm, in °C, that meets the following relationship: Tm°C<601.4*Density in g/cc−447.8°C.