Polyolefin Blend Composition for Extrusion Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polyethylene compositions used in extrusion coating and lamination processes face challenges in achieving optimal interlayer bonding while maintaining acceptable neck-in and drawdown performance properties.
Innovation Solution
A polyolefin blend composition comprising a linear low density polyethylene with specific density, molecular weight distribution, and zero shear viscosity ratio, combined with a low density polyethylene, optimized for extrusion coating and lamination applications, enhancing interlayer bonding and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional polyethylene compositions are used in extrusion coating and lamination processes, then processing is simplified, but interlayer bonding is insufficient
Solution Approach 1:
The patent employs composite materials by formulating a polyethylene composition that blends different polyethylene types (LDPE and LLDPE) with specific density ranges (0.915-0.930 g/cm³ for LDPE and 0.890-0.940 g/cm³ for LLDPE). This composite approach enhances interlayer bonding strength through the synergistic effects of branched and linear polyethylene structures, while maintaining processing simplicity through a unified composition design.
Solution Approach 2:
The patent applies parameter changes by precisely controlling the density parameters of the polyethylene components within specific ranges (0.915-0.930 g/cm³ and 0.890-0.940 g/cm³). By optimizing these physical parameters, the composition achieves improved interlayer bonding without requiring complex processing equipment or procedures, resolving the contradiction between bonding strength and composition complexity.
2Strength
If polyethylene composition is optimized for interlayer bonding, then bonding strength improves, but neck-in and drawdown performance deteriorate
Solution Approach 1:
The patent applies local quality by assigning different functional roles to different components within the polyethylene composition. The LDPE component (density 0.915-0.930 g/cm³) provides interlayer bonding through its branched structure, while the LLDPE component (density 0.890-0.940 g/cm³) maintains neck-in and drawdown performance. This localized functional distribution allows simultaneous optimization of bonding strength and manufacturing precision without compromise.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the density parameters of the polyethylene components to specific ranges. The LDPE density (0.915-0.930 g/cm³) optimizes for bonding, while the LLDPE density (0.890-0.940 g/cm³) optimizes for dimensional stability during processing. This parameter optimization enables the composition to achieve both improved interlayer bonding and acceptable neck-in/drawdown performance.
3Ease of manufacture
If linear low density polyethylene with high comonomer content is used, then processability improves, but interlayer bonding deteriorates
Solution Approach 1:
The patent applies parameter changes by controlling the density of the LLDPE component within the range of 0.890-0.940 g/cm³, which corresponds to specific comonomer content levels. This density parameter control ensures adequate processability while maintaining sufficient interlayer bonding strength, resolving the contradiction between ease of manufacture and bonding strength.
Solution Approach 2:
The patent uses composite materials by combining LDPE and LLDPE in a unified composition. The LDPE component compensates for the reduced bonding capability of LLDPE with high comonomer content, while the LLDPE provides processability benefits. This composite approach balances processability and interlayer bonding strength through the synergistic interaction of different polyethylene types.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The instant invention provides a polyolefin blend composition suitable for extrusion coating or extrusion lamination applications, and multilayer structure and articles made therefrom. The polyolefin blend composition suitable for extrusion coating or extrusion lamination applications according to the present invention comprises (a) a linear low density polyethylene composition comprising: less than or equal to 100 percent by weight of the units derived from ethylene; less than 35 percent by weight of units derived from one or more ?-olefin comonomers; wherein said polyethylene composition has a density in the range of 0.890 to 0.940 g/cm3, a molecular weight distribution (Mw/Mn) in the range of 2.5 to 4.5, a melt index (I2) in the range of 4 to 30 g/10 minutes, a molecular weight distribution (Mz/Mw) in the range of from 2.0 to 3, vinyl unsaturation of less than 0.1 vinyls per one thousand carbon atoms present in the backbone of said composition, and a zero shear viscosity ratio (ZSVR) in the range from 1 to 1.2; and (b) less than 50 percent by weight of a low density polyethylene composition having a density in the range of 0.915 to 0.930 g/cm3, a melt index (I2) in the range of 0.1 to 10 g/10 minutes, and a molecular weight distribution (Mw/Mn) in the range of 6 to 15.