Polyolefin Pellet Posttreatment for Bulk Density and Volatile Removal
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Solution Overview
Problem
Current methods for adjusting the bulk density of pelletized polyolefin resins are insufficient, leading to suboptimal performance in pipe manufacturing and increased shipping costs, as they cannot achieve the desired density without altering the pellet's size or geometry, and fail to effectively remove volatile and organic materials for applications requiring low odor and taste profiles.
Innovation Solution
A process involving pre-heating pellets to a hold temperature below their softening point, maintaining them for 4 to 18 hours, purging volatile materials, and treating them with a thermal destruction process to increase bulk density and reduce organic materials, such as waxes and oligomers, while maintaining or adjusting their level for specific applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If current methods adjust bulk density by changing pellet length or geometry, then bulk density is improved, but pellet appearance and dimensions are adversely affected
Solution Approach 1:
The patent applies parameter changes by heating pellets to temperatures between 80-120°C for extended periods (4-18 hours), which modifies the bulk density through thermal treatment without altering pellet geometry. This temperature-time parameter combination enables density adjustment while preserving pellet appearance
Solution Approach 2:
The patent implements preliminary action by performing heat treatment on pellets before they are used in extrusion or shipping. This pre-treatment process consolidates the pellet structure in advance, achieving the desired bulk density before the pellets encounter any geometric constraints or processing steps
2Quantity of substance
If pellets are shipped with lower bulk density, then shipping container capacity is reduced, but shipping cost per mass increases
Solution Approach 1:
By changing the temperature parameter during storage and transport (maintaining elevated temperatures), the patent increases bulk density, which directly increases the quantity of pellets per shipping container and reduces shipping costs on a mass basis
3Productivity
If pellets are fed with improper bulk density to grooved feed extruders, then throughput rate decreases, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-adjusting the bulk density of pellets through heat treatment before they enter the extrusion process. This ensures that when pellets are fed to grooved feed extruders, they have the optimal density for maximum throughput rate and consistent extrusion performance
Solution Approach 2:
The patent changes the bulk density parameter of pellets through thermal treatment, enabling them to flow properly into grooved feed extruders and maintain stable extrusion rates, thereby improving both productivity and manufacturing precision
4Object-generated harmful factors
If volatiles and organic materials are not removed from resin, then processing is simpler, but odor and taste properties deteriorate
Solution Approach 1:
The patent merges the bulk density adjustment and volatile removal functions into a single heat treatment process. By heating pellets to 80-120°C for extended periods, it simultaneously consolidates the pellet structure and drives off volatiles and organic materials, eliminating the need for separate processing steps
Solution Approach 2:
The patent uses parameter changes (temperature and time) to achieve dual benefits: the elevated temperature and extended duration both increase bulk density and remove harmful volatiles, reducing odor and taste issues without requiring additional complex equipment
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 process achieves increased bulk density and improved odor and taste properties in polyolefin resins, enhancing pipe production efficiency and reducing shipping costs by allowing higher pellet mass per container, while ensuring compliance with food and water contact standards.
Implementation Method 1
heating the pellets in said holding vessel to a hold temperature for 4 to 18 hours at or below the softening point of the polyolefins
Implementation Method 2
purging the holding vessel of volatile materials
Implementation Method 3
treating the purged volatile materials by exposing them to at least one thermal destruction process
Data Source
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AI summary
A posttreatment and a system for posttreating pelletized polyolefin resins. The posttreatment comprises a heating step.