Thin Slit Heat Exchanger for Uniform Hot Melt Adhesive Heating

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Solution Overview

Problem

Hot melt adhesive materials exhibit thermal insulative properties, leading to uneven heat distribution, with regions near the heater being hotter than those farther away, and the materials do not flow in a manner that encourages heat distribution, resulting in inefficient heating and potential degradation at elevated temperatures.

Innovation Solution

The use of heat exchange devices with fluid passageways featuring thin slit sections that direct and heat the liquid adhesive material, maintaining it at lower temperatures before heating, thereby reducing energy consumption and preventing degradation, while ensuring even and thorough heating through the design of concentric body segments and strategically placed heating elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional heating methods are used to heat liquid adhesive material, then the adhesive material can reach application temperature, but the heating is uneven and energy consumption increases due to thermal insulative properties

Engineering Contradiction:
Improvetemperature uniformityVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by creating a temperature gradient within the adhesive material through controlled heating zones. The heating element heats the adhesive locally, and the viscosity changes create natural convection patterns that distribute heat throughout the material, achieving uniform temperature without excessive energy input.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by exploiting the temperature-dependent viscosity characteristics of the adhesive material. As the adhesive is heated, its viscosity decreases, which enhances flow and heat distribution. This natural parameter change enables efficient heat transfer without requiring additional energy input.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If elevated temperatures are applied to liquid adhesive material, then heating efficiency improves, but material degradation occurs

Engineering Contradiction:
Improveheating efficiencyVSAvoidmaterial degradation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent employs periodic action through natural convection cycles driven by temperature-induced viscosity changes. The adhesive material undergoes continuous cyclic motion as warmer, less viscous regions rise and cooler, more viscous regions sink, creating an efficient periodic heat distribution mechanism that avoids sustained high-temperature exposure and prevents degradation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent replaces mechanical stirring or pumping systems with a passive thermal convection mechanism. By utilizing the inherent temperature-viscosity relationship of the adhesive, the system achieves efficient heat distribution through natural fluid motion, eliminating the need for additional mechanical energy input that could cause overheating and degradation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If liquid adhesive material is heated uniformly, then application quality improves, but the thermally insulative nature of the material resists heat transfer

Engineering Contradiction:
Improveheating uniformityVSAvoidheat transfer efficiency
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent exploits parameter changes in the adhesive material's viscosity as a function of temperature. By heating the material to specific temperature thresholds, the viscosity decreases naturally, which enhances heat transfer efficiency. This parameter-driven approach ensures uniform heating while overcoming the material's insulative properties through controlled physical changes.

Inventive Principle:
Principle #35Parameter changes

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 approach allows for efficient and uniform heating of liquid adhesive materials, reducing energy consumption and minimizing degradation, ensuring the material is at the correct temperature for bonding applications without overheating, and promoting even heat distribution across the adhesive.

Implementation Method 1

a heating element for heating the liquid adhesive material flowing through the thin slit section to the application temperature

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Implementation Method 2

the thin slit section further having a first dimension and a second dimension transverse to the fluid flow direction. The first dimension and the length are substantially greater than the second dimension

Methodology Applied
Scientific EffectThermal Conduction: Conduction (thermal)

Data Source

PatentEP2857111B1Heat exchange devices, liquid adhesive systems, and related methods
Publication Date: 2020.05.27 NORDSON CORP
  • EP2857111B1 patent drawingFigure 1~3
  • EP2857111B1 patent drawingFigure 2
  • EP2857111B1 patent drawingFigure 4

AI summary

A heat exchange device (10, 110) for heating liquid adhesive material to an application temperature suitable for an adhesive bonding application includes a body (12, 112) having an inlet (14, 140) configured to receive a flow of liquid adhesive material and an outlet (16, 134) configured to provide the liquid adhesive material to a dispensing device (20, 114) for the adhesive bonding application. A fluid passageway (22, 140) in the body (12, 112) connects the inlet (14, 140) and the outlet (16, 134). The fluid passageway (22, 140) includes a thin slit section (28, 146) having a length along a fluid flow direction between the inlet (14, 140) and the outlet (16, 134), the thin slit section (28, 146) further having a first dimension and a second dimension transverse to the fluid flow direction. The first dimension and the length are substantially greater than the second dimension. The heat exchange (10, 110) further includes a heating element (56, 170) for heating the liquid adhesive material flowing through the thin slit section (28, 146) to the application temperature.