Segmented Back Reflector for IR Preform Heating

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing heating devices for preforms in stretch blow molding face inefficiencies due to radiation losses and material damage from high temperature fluctuations, leading to costly production stoppages and reduced machine efficiency.

Innovation Solution

A heating device with a segmented back reflector and filter system, using ceramic materials and a floating mount to minimize distance between IR emitters and reflectors, and a segmented structure to allow controlled expansion, reducing stress and radiation loss, and a counter-reflector to enhance energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the distance between IR emitters and reflectors is minimized to improve energy efficiency, then radiation loss is reduced and energy efficiency is improved, but the reflector material is damaged by high temperature fluctuations

Engineering Contradiction:
Improveradiation lossVSAvoidreflector material damage
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The back reflector is divided into multiple segments that can move independently relative to each other. This segmentation allows the reflector to accommodate thermal expansion and temperature fluctuations without causing material damage, while maintaining minimal distance to IR emitters for optimal energy efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reflector segments are designed to be dynamically adjustable, allowing them to move and adapt to temperature changes. This dynamic capability enables the system to maintain both close proximity to IR emitters for energy efficiency and sufficient thermal tolerance to prevent material damage.

Inventive Principle:
Principle #15Dynamics

2Use of energy by stationary object

If reflectors are placed closer to IR emitters to reduce radiation loss, then energy efficiency is improved, but stress on the reflector material increases due to high temperature

Engineering Contradiction:
Improveenergy efficiencyVSAvoidreflector material stress
Core Design Contradiction:
Use of energy by stationary objectVSStrength

Solution Approach 1:

Dividing the reflector into segments distributes the thermal stress across multiple independent units, reducing the overall stress on any single segment while maintaining close proximity to IR emitters for high energy efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reflector segments can change their physical parameters (position, orientation) in response to temperature changes, allowing them to maintain optimal distance from IR emitters for energy efficiency while adapting to thermal conditions to reduce material stress.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If a single large reflector is used to minimize radiation loss, then energy efficiency is improved, but the reflector is more susceptible to breakage from temperature fluctuations

Engineering Contradiction:
Improveradiation lossVSAvoidtemperature-induced breakage
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The large reflector surface is segmented into multiple smaller units that can move independently. This maintains the overall reflective surface area needed for energy efficiency while reducing the susceptibility to breakage from thermal stress.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The segmented design provides a cushioning effect against thermal stress by allowing individual segments to move and absorb temperature-induced expansions and contractions, preventing the kind of stress concentration that would lead to breakage in a single large reflector.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 solution minimizes radiation loss, allows closer placement of reflectors to IR emitters, reduces material damage, and improves energy efficiency by optimizing the reflection of radiation back onto the preforms, leading to increased production efficiency and reduced maintenance costs.

Implementation Method 1

A plurality of IR emitters (11) are arranged one above the other in a row parallel to the longitudinal axis of the preform (20) in the heating lane

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

The emitters are therefore all at the same distance from the longitudinal axis of the preform being irradiated

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 3

at least one rear reflector (15) is assigned to the IR radiators (11), which reflects the radiation emitted to the rear into the heating alley

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 4

a segmented back reflector and filter system, using ceramic materials and a floating mount to minimize distance between IR emitters and reflectors, and a segmented structure to allow controlled expansion, reducing stress and radiation loss

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 5

a segmented back reflector and filter system, using ceramic materials and a floating mount to minimize distance between IR emitters and reflectors

Methodology Applied
Scientific EffectThermal expansion compensation: Thermal Expansion

Data Source

PatentEP2444234B2Heating device for tempering pre-forms
Publication Date: 2020.11.25 KRONES AG
  • EP2444234B2 patent drawingFigure 1
  • EP2444234B2 patent drawingFigure 2
  • EP2444234B2 patent drawingFigure 3

AI summary

The invention relates to a heating device for heating preforms prior to processing in a stretch blow molding machine. The heating device comprises a heating lane with a plurality of IR emitters arranged parallel to the longitudinal axis of the preforms to be heated. Each IR emitter is associated with at least one back reflector and/or at least one filter, which is segmented.