Acoustic Solid-State Mixing of Polyolefins Without Thermal Degradation
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Solution Overview
Problem
Existing methods for mixing polyolefins with additives rely on mechanical blending or melting, which can lead to oxidative degradation and premature crosslinking, and fail to achieve a homogeneous mixture without thermal stress.
Innovation Solution
Applying acoustic energy at a frequency of 20 to 100 Hz to a mixture of polyolefin solids and particulate additives without mechanical agitation, maintaining temperatures below the melting points of both, to create a homogeneous mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical blending or melting is used to mix polyolefins with additives, then mixing efficiency is improved, but oxidative degradation and premature crosslinking occur
Solution Approach 1:
The patent replaces mechanical blending systems with an acoustic field system. Acoustic waves at frequencies of 20-100 Hz are applied to the solid polyolefin and additive mixture, creating acoustic streaming and particle vibration that achieves homogeneous mixing without mechanical contact or high shear forces that cause degradation.
Solution Approach 2:
The patent changes the physical state parameters by maintaining the polyolefin in solid form throughout the mixing process, avoiding melting. The acoustic energy parameters (frequency 20-100 Hz, specific power density) are optimized to achieve mixing effectiveness while preventing thermal degradation and oxidative damage.
2Manufacturing precision
If melting is used to mix polyolefins with additives, then homogeneity is improved, but thermal stress increases
Solution Approach 1:
The patent substitutes thermal-mechanical melting processes with acoustic field action. Solid polyolefin particles are mixed in the solid state using acoustic waves, eliminating the need to raise temperature to melting point, thus avoiding thermal stress while achieving homogeneous distribution of additives.
Solution Approach 2:
The patent maintains temperature parameters below the melting point of polyolefin throughout the process, using acoustic energy parameters (frequency and power density) instead of thermal energy to achieve the mixing effect that traditionally required melting.
3Temperature
If acoustic energy is applied to mix solid polyolefins with additives, then thermal stress is reduced, but mixing effectiveness may be insufficient
Solution Approach 1:
The patent applies mechanical vibration through acoustic waves at frequencies of 20-100 Hz. This vibration causes solid polyolefin particles and additive particles to oscillate and collide, breaking up agglomerates and achieving homogeneous mixing without thermal input, thus maintaining effectiveness while reducing thermal stress.
Solution Approach 2:
The patent uses periodic acoustic cycles at specific frequencies (20-100 Hz) to create repeated compression and rarefaction phases in the material. This periodic action enhances particle dispersion and mixing efficiency through cyclic stress application, achieving thorough mixing without sustained thermal exposure.
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 method achieves a homogeneous mixture without melting, reducing thermal stress and improving properties such as cure and mechanical strength, while avoiding oxidative degradation and premature crosslinking.
Implementation Method 1
applying acoustic energy at a frequency of from 20 to 100 hertz to a heterogeneous mixture comprising the polyolefin solids and the particulate solid additive for a period of time sufficient to substantially intermix the polyolefin solids and the particulate solid additive together
Implementation Method 2
maintaining temperature of the heterogeneous mixture (and, optionally, maintaining temperature of the homogeneous mixture made therefrom) below the melting point of the at least one particulate solid additive and below the melting temperature of the polyolefin solids
Data Source
AI summary
A method of making a homogeneous mixture of polyolefin solids and a particulate solid additive without melting the polyolefin solids or the particulate solid additive during the making. The method comprises applying acoustic energy at a frequency of from 20 to 100 hertz to a heterogeneous mixture comprising the polyolefin solids and the particulate solid additive for a period of time sufficient to substantially intermix the polyolefin solids and the particulate solid additive together and while maintaining temperature of the heterogeneous mixture below the melting point of the at least one particulate solid additive and below the melting temperature of the polyolefin solids, thereby making the homogeneous mixture without melting the polyolefin solids or the at least one particulate solid additive.