Polyolefin Fiber Gel Reduction Metallocene Catalyst
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing high tenacity fibers with polyolefin exhibit issues such as wide molecular weight distribution, gel formation, and reduced processibility due to the use of Ziegler-Natta catalysts, which hinder the achievement of high molecular weight and narrow molecular weight distribution necessary for excellent drawing characteristics and tenacity.
Innovation Solution
A polyolefin powder with a weight average molecular weight of 100,000 to 300,000 g/mol and a molecular weight distribution of 2.0 to 3.2 is developed, using a single metallocene supported catalyst with a borate-based cocatalyst to control molecular weight distribution and reduce gel formation, resulting in a fiber with improved tenacity and processibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If Ziegler-Natta catalyst is used to produce polyethylene, then good processibility is achieved, but molecular weight distribution becomes wide and mechanical properties deteriorate
Solution Approach 1:
The patent changes the catalyst system from Ziegler-Natta to metallocene catalyst, fundamentally altering the polymerization parameters to achieve narrow molecular weight distribution (PDI 2.0-3.2) while maintaining processibility through controlled polymerization conditions
2Manufacturing precision
If metallocene catalyst is used to achieve narrow molecular weight distribution, then drawing characteristics improve, but gel formation occurs during extrusion
Solution Approach 1:
The patent extracts and removes the harmful gel formation issue by using a specific metallocene catalyst system with controlled polymerization conditions, separating the beneficial narrow molecular weight distribution from the harmful gel formation that occurs with conventional catalysts
Solution Approach 2:
The patent converts the potential harm of gel formation into a benefit by carefully controlling polymerization parameters to achieve uniform molecular weight distribution without gel formation, turning a problematic area into a successful application
3Strength
If high molecular weight polyolefin is used to improve tenacity, then drawing ratio increases, but gel formation during extrusion prevents proper dissolution
Solution Approach 1:
The patent changes the molecular weight parameters to achieve high weight average molecular weight (100,000-300,000 g/mol) while controlling the distribution to prevent gel formation, enabling both high tenacity and proper processibility
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 solution achieves a significant reduction in gel formation, enabling the production of fibers with high tenacity and extended tensile strength half-life, while maintaining excellent processibility and drawing characteristics, thus overcoming the limitations of existing technologies.
Implementation Method 1
using a single metallocene supported catalyst with a borate-based cocatalyst to control molecular weight distribution
Data Source
AI summary
The present invention relates to polyolefin powder for preparing fiber, and fiber comprising the same. According to the present invention, provided is polyolefin, which exhibits a high molecular weight range and narrow molecular weight distribution and in which the formation of a gel deteriorating the quality of fiber is reduced. Therefore, by using the polyolefin, the present invention exhibits molecular weight, density and narrow molecular weight distribution, which are equivalent to those of conventional polyolefin, but the number of gels having a large particle diameter is remarkably reduced, and therefore, the present invention can provide fiber having excellent tenacity and tensile strength half-life.