Polypropylene Clarification with DBS and DMDBS Nucleating Agents
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Solution Overview
Problem
There is a need for a composition or process that produces polyolefin articles with low haze and reduced energy consumption, while also achieving shorter molding cycle times, especially for high MFR resins which are less viscous and can be processed at lower temperatures, to enhance manufacturing efficiency and transparency.
Innovation Solution
A polyolefin composition comprising a polypropylene resin with a melt flow index of at least 20, combined with bis(3,4-dimethylbenzylidene) sorbitol (DMDBS) and dibenzylidene sorbitol (DBS), where DMDBS is 15-60 wt.% of the total amount, processed at temperatures of 210°C or lower, facilitating reduced haze and energy usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If higher processing temperatures are used to process polyolefin resin, then the resin can be molded more easily, but the cooling time increases and energy consumption increases
Solution Approach 1:
The patent changes the chemical composition parameters of the resin by incorporating specific nucleating agents (DBS and DMDBS) in optimized ratios. This modification allows the resin to crystallize effectively at lower temperatures, thereby reducing cooling time and energy consumption while maintaining ease of molding
Solution Approach 2:
The patent creates a composite resin system by combining polyolefin resin with a specific blend of nucleating agents (DBS and DMDBS) in defined ratios. This composite formulation enhances the resin's processing characteristics, enabling lower temperature molding and faster cooling without sacrificing manufacturability
2Ease of manufacture
If higher processing temperatures are used to process polyolefin resin, then the resin can be molded more easily, but the energy consumption increases
Solution Approach 1:
The patent modifies the thermal and crystallization parameters of the resin through the addition of specific nucleating agents. This enables the resin to be processed at lower temperatures, directly reducing the energy input required for heating and maintaining the resin in a moldable state
Solution Approach 2:
By formulating a composite resin system with optimized nucleating agent content, the patent reduces the processing temperature requirement, which in turn decreases the energy consumption associated with heating, holding, and cooling the resin during the molding cycle
3Reliability
If DBS derivative compounds are used as nucleating agents, then nucleation and clarification are enhanced, but haze increases at very low processing temperatures
Solution Approach 1:
The patent adjusts the chemical composition parameters by combining two different nucleating agents (DBS and DMDBS) in specific ratios. This blended formulation modifies the nucleation behavior to maintain effectiveness at lower temperatures while controlling the optical properties to minimize haze formation
Solution Approach 2:
The patent creates a composite nucleating system by blending DBS and DMDBS compounds. This composite approach synergistically combines the nucleation-enhancing properties of both compounds while balancing the optical clarity, achieving reliable nucleation without excessive haze even at lower processing temperatures
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 combination of DMDBS and DBS in polypropylene resins achieves significantly reduced haze and energy consumption, enabling faster cycle times and higher production efficiency, with a synergistic effect that is particularly beneficial at lower processing temperatures, resulting in improved transparency and cost-effectiveness.
Implementation Method 1
DBS-based compounds enhance nucleation and clarification of polyolefins by providing a fibrous network in the polymer. DBS derivatives provide a fibrous network that serves as a template for polyolefin recrystallization that results in faster and more orderly crystal growth during the polymer cooling process.
Implementation Method 2
As polyolefin articles are fabricated in melt processing, the polymer crystallizes. Crystals tend to organize into clusters. DBS-based compounds enhance nucleation and clarification of polyolefins by providing a fibrous network in the polymer.
Implementation Method 3
Haze is a measurement of the amount of transmitted light that is scattered as the light passes through an article. Haze is expressed as a percentage (ASTM Method D1003-00). The greater the haze of an injection molded polypropylene article, the more opaque the article appears.
Data Source
Figure 1~2
AI summary
Clarified polyolefins such as polypropylene are used widely to make polymer articles, containers, and the like. Such articles may be manufactured by the injection of molten polymer into a mold or forming device in manufacturing processes at high rates. A clarified composition is provided to achieve optimized clarity and organoleptic performance at lower processing temperatures and/or within a polypropylene resin having a higher melt flow rate.