Injection Nozzle Air Gap Thermal Insulation

Solution Overview

Problem

Injection blow molding machines require external heat sources to maintain resin temperature along the nozzle length, increasing costs and potential for malfunction due to heat loss.

Innovation Solution

A two-piece injection nozzle with a thermally conductive insert and an insulating air gap along its length, eliminating the need for external heat sources by maintaining resin temperature through thermal conduction from the manifold block.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If an external heat source is used to maintain resin temperature along the nozzle, then the resin temperature is maintained, but the cost increases and the risk of breakage and malfunction increases

Engineering Contradiction:

Improveresin temperatureVSAvoidheating cost

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The nozzle structure itself provides the heating function through its dual-material construction. The thermally conductive material (e.g., copper or aluminum) in thermal contact with the heated manifold conducts heat to the resin, while the thermally insulating material (e.g., plastic or ceramic) reduces heat loss to the environment. This self-heating mechanism eliminates the need for external heat sources.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The nozzle is constructed from two or more materials with different thermal properties. The thermally conductive material ensures heat transfer from the manifold to the resin, while the thermally insulating material minimizes heat loss along the nozzle length. This composite construction optimizes both heat transfer and thermal insulation within a single integrated component.

Inventive Principle:

Principle #40Composite materials

2Temperature

If an external heat source is used to maintain resin temperature, then the resin temperature is maintained, but the complexity of the system increases

Engineering Contradiction:

Improveresin temperatureVSAvoidheating system complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The heating and insulation functions are merged into the nozzle structure itself rather than being separate external components. The dual-material nozzle construction integrates thermal management directly into the flow path, eliminating the need for external heaters, temperature sensors, and control systems that would increase system complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The nozzle structure itself provides the heating function through its dual-material construction. The thermally conductive material (e.g., copper or aluminum) in thermal contact with the heated manifold conducts heat to the resin, while the thermally insulating material (e.g., plastic or ceramic) reduces heat loss to the environment. This self-heating mechanism eliminates the need for external heat sources.

Inventive Principle:

Principle #25Self-service

3Use of energy by moving object

If the nozzle is made of highly thermally conductive material, then heat transfer from manifold to resin is improved, but heat loss along the nozzle length increases

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidheat loss

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The nozzle is constructed from two or more materials with different thermal properties. The thermally conductive material ensures heat transfer from the manifold to the resin, while the thermally insulating material minimizes heat loss along the nozzle length. This composite construction optimizes both heat transfer and thermal insulation within a single integrated component.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

Different sections of the nozzle have different thermal properties tailored to their specific functions. The section in contact with the manifold and the resin flow path uses thermally conductive material to maximize heat transfer, while the outer surface and sections farther from the heat source use thermally insulating material to minimize heat loss to the environment.

Inventive Principle:

Principle #3Local quality

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 nozzle maintains resin temperature without external heating, reducing costs and minimizing heat loss, ensuring consistent operating conditions throughout the molding process.

Implementation Method 1

The resin is heated to a beginning operating temperature from the heat supplied by the manifold via thermal conduction through the nozzle base

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The air gap serves to insulate the resin flowing through the nozzle insert and minimize heat loss along the axial length of the nozzle forward of the insulating gap

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentUS8714965B2Injection nozzle with enhanced heat transfer characteristics

Publication Date: 2014.05.06 R & D TOOL AND ENGINEERING INC

AI summary

An injection nozzle that can be used in an injection blow molding system without use of an external heat source comprises a two-piece structure broadly including a structural outer body for coupling the nozzle to a resin manifold and a thermally conductive insert. At least a portion of an axial length of the insert has an outer diameter that is less than an inner diameter of a coinciding coaxial portion of the outer body, such that the differences in the inner and outer diameters present an insulating air gap along at least a portion of the nozzle length. A sufficient operating temperature for hot melt resin can then be obtained without use of the external heat source.