Polyethylene Blend Composition Reducing Chill Roll Buildup
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Solution Overview
Problem
Current polyethylene compositions used in extrusion processes, such as extrusion coating and cast film production, experience significant chill roll buildup issues, leading to undesirable processability problems and equipment contamination.
Innovation Solution
A polyethylene blend composition comprising 60-95% linear polyethylene with specific density, molecular weight distribution, and melt index ranges, combined with 5-40% low density polyethylene, designed to reduce chill roll buildup by minimizing contamination and improving processability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional polyethylene compositions are used in extrusion processes, then the extrusion process can be performed, but significant chill roll buildup occurs leading to processability problems
Solution Approach 1:
The patent changes the compositional parameters of polyethylene by creating a blend of specific components (linear polyethylene with controlled density and molecular weight distribution, and low-density polyethylene with specific melt index) to reduce chill roll buildup while maintaining extrusion processability
Solution Approach 2:
The patent uses a composite polyethylene blend composition combining linear polyethylene (60-95 wt%) and low-density polyethylene (5-40 wt%) to achieve reduced chill roll buildup, leveraging the complementary properties of each component
2Productivity
If currently available polyethylene compositions are used, then production can proceed, but accumulation of contaminants on equipment such as chill roll occurs requiring equipment clean up
Solution Approach 1:
The patent modifies the polyethylene composition parameters (density range 0.917-0.920 g/cm³, controlled molecular weight distribution, specific melt index range) to minimize contaminant accumulation on equipment, thereby reducing cleanup time and maintaining productivity
3Reliability
If conventional polyethylene compositions are used, then films and coating layers can be produced, but undesirable processability issues arise due to chill roll buildup
Solution Approach 1:
The patent employs a composite polyethylene blend with specific component ratios (60-95% linear polyethylene and 5-40% low-density polyethylene) to achieve both process stability and ease of operation by reducing chill roll buildup during extrusion processes
Data Source
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AI summary
The instant invention provides a polyethylene blend composition having reduced chill roll buildup during extrusion process, and films and coating layers made therefrom. The polyethylene blend composition according to the present invention provide reduced chill roll buildups during extrusion process, and comprises: (a) from 60 to 95 percent by weight of a linear polyethylene composition comprising less than or equal to 100 percent by weight of the units derived from ethylene, and less than 15 percent by weight of units derived from one or more a-olefin comonomers; wherein said linear polyethylene composition has a density in the range of from 0.917 to 0.975 g/cm3, a molecular weight distribution (Mw/Mn) in the range of from 1.70 to 3.62, a melt index (I2) in the range of from 2 to 50 g/10 minutes, and a vinyl unsaturation in the range of from less than 0.06 vinyls per one thousand carbon atoms present in the linear polyethylene composition; and (b) from 5 to 40 percent by weight of a low density polyethylene composition (LDPE) having a density in the range of from 0.915 to 0.930 g/cm3, and a melt index (I2) in the range of from 0.4 to 10; wherein the polyethylene blend composition has a density in the range of 0.917 to 0.960 g/cm3 and a melt index (I2) in the range of from 2 to 30 g/10 minutes.