Liquid Injection Barrel Element Cooling for Extruder Safety

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Solution Overview

Problem

The temperature control of liquids injected into extruder barrels is challenging, leading to issues like premature boiling, decomposition, and safety risks due to high temperatures, especially when dealing with flammable liquids, which can result in unsafe conditions and suboptimal foam production in manufacturing irradiation crosslinked polypropylene foam.

Innovation Solution

A liquid injection barrel element with integrated cooling channels and a temperature sensor well is used to maintain the temperature of injected liquids below their boiling point, ensuring safe and controlled injection by adjusting the flowrate of cooling fluid based on temperature readings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If liquid additives are injected into the extruder barrel at high temperature, then the extrusion process can proceed efficiently, but the liquid may undergo premature boiling, decomposition, and polymerization

Engineering Contradiction:
Improveextrusion process efficiencyVSAvoidliquid additive stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The extruder barrel is divided into separate heating zones, with the injection zone maintained at a lower temperature than the extrusion zones. This segmentation allows the liquid additive to be injected in a cooler environment, preventing premature boiling and decomposition, while the downstream zones provide the necessary heat for efficient extrusion processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The liquid additive is pre-cooled before injection into the extruder barrel by introducing it into a cooling zone or using pre-cooling channels. This preliminary cooling action ensures the liquid remains stable during injection and mixing, avoiding decomposition before the extrusion process begins.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the extrusion temperature is increased to improve flow characteristics, then processing efficiency increases, but flammable liquids may produce extreme safety risks

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidflammability risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

Different temperature zones are created within the extruder barrel, with the injection and mixing zones maintained at lower temperatures to prevent flammable liquid vaporization, while downstream extrusion zones operate at higher temperatures for efficient processing. This local quality differentiation addresses both safety and productivity requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

A cooling fluid acts as an intermediary medium, introduced through cooling channels in the barrel to absorb excess heat from the liquid additive and surrounding materials. This intermediary cooling mechanism prevents flammable liquids from reaching dangerous temperatures while allowing the extrusion process to proceed efficiently.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If cooling channels are added to control liquid temperature, then safety and temperature control improve, but device complexity increases

Engineering Contradiction:
Improvetemperature controlVSAvoidbarrel element structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cooling channels in the barrel element serve multiple functions: they cool the liquid additive during injection, maintain appropriate temperatures in different zones, and prevent overheating of flammable materials. This multi-functionality reduces the need for separate cooling devices, thereby limiting the increase in overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The cooling channels are integrated directly into the barrel element structure, merging the cooling function with the existing extrusion barrel. This integration eliminates the need for separate external cooling systems and reduces the number of discrete components, thereby limiting the increase in device complexity while achieving effective temperature control.

Inventive Principle:
Principle #5Merging (Combining)

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

This solution effectively prevents high heat-related reactions, maintains stable flow characteristics, and enhances safety by minimizing flammable fumes, resulting in improved control over the extrusion process and the quality of irradiation crosslinked polypropylene foam production.

Implementation Method 1

a cooling inlet channel extending from a second external side of the body in a first direction; a cooling outlet channel extending from a third external side of the body in the first direction; and a plurality of connecting cooling channels extending in a second direction

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3946876B1Liquid injection barrel element for barrel extruder
Publication Date: 2024.07.24 TORAY PLASTICS (AMERICA) INC
  • EP3946876B1 patent drawingFigure 1
  • EP3946876B1 patent drawingFigure 2
  • EP3946876B1 patent drawingFigure 3

AI summary

Described herein is a liquid injector for a barrel extruder as well as methods and processes of manufacturing irradiation crosslinked polypropylene foam. In some embodiments, this includes a liquid injection barrel element (5) that is incorporated in an extruder barrel that includes at least one injection port (11), a temperature sensor well (22), and cooling channels (19, 20).