Double-Walled Mold Hollow Chambers for Thermal Control

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Solution Overview

Problem

Conventional methods for producing molded skins and bodies with varying wall thicknesses are inefficient, requiring extensive equipment and resulting in material waste, as they struggle to achieve precise temperature control and energy savings.

Innovation Solution

A double-walled mold design with hollow chambers in the front and rear walls, allowing for controlled heat transfer and insulation, enabling the production of molded skins with different wall thicknesses and recesses while reducing energy consumption and production time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional hot air chambers or ovens are used for heating and cooling molds, then the mold can be heated and cooled, but the process takes a very long time and throughput is low

Engineering Contradiction:
Improvemold temperatureVSAvoidheating and cooling time
Core Design Contradiction:
TemperatureVSLoss of time

Solution Approach 1:

The mold is divided into multiple heating zones with independent temperature control. Each zone can be heated or cooled separately through individually controlled heating elements, allowing different parts of the mold to be at different temperatures simultaneously. This segmentation enables precise thermal management and reduces overall cycle time by targeting specific areas that need temperature adjustment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the mold are equipped with different heating capabilities and temperature settings according to their specific requirements. The mold includes zones with varying wall thicknesses that receive differentiated thermal treatment, with thinner areas receiving more intensive heating and thicker areas receiving less, optimizing the overall processing efficiency.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If conventional methods are used to produce molded skins with different wall thicknesses, then production can proceed, but extensive equipment is required and material waste occurs

Engineering Contradiction:
Improvewall thickness controlVSAvoidequipment requirements
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The mold incorporates zones with different wall thicknesses designed into its structure. By varying the mold wall thickness in different areas, the plastic material forms skins of different thicknesses during the molding process. This eliminates the need for complex post-processing equipment to create variable thickness profiles, as the desired geometry is achieved directly during forming.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of using complex equipment to add or remove material to achieve different wall thicknesses, the invention inverts the approach by designing the mold itself with variable thickness walls. The mold structure directly imprints the desired variable thickness profile onto the molded skin, simplifying the entire production system.

Inventive Principle:
Principle #13The other way round (Inversion)

3Temperature

If uniform heating is applied to the mold, then the entire mold surface reaches the same temperature, but this prevents targeted production of different wall thicknesses

Engineering Contradiction:
Improveuniform temperature distributionVSAvoidwall thickness variation
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The mold features localized heating zones with independently controllable temperature and heating intensity. Each zone can be heated to different temperatures based on the desired wall thickness at that location. This local quality control allows precise manipulation of plastic flow and solidification rates to achieve the target variable thickness profile.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The heating parameters (temperature, power, duration) are varied across different mold zones to control the thermal history of the plastic material at each location. By changing these parameters locally, the process achieves different cooling rates and solidification times, resulting in the desired variation in wall thickness throughout the molded skin.

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 design allows for targeted production of molded skins with varying thicknesses and recesses, enhancing energy efficiency and production speed by controlling heat transfer and insulation, thereby achieving material savings and improved process control.

Implementation Method 1

a double-walled electroforming mold is used, on the rear wall of which a large number of inlet openings and outlet openings for the heating and cooling medium are formed

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

rapid heating and cooling evenly over the entire surface of the mold

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the hollow chamber acts as insulation and prevents heat transfer from the heating or cooling medium to the inner contour of the front wall

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP2136982B1Mold and method for producing molded skins and molded bodies made of plastic
Publication Date: 2013.05.29 SMP DEUTLAND
  • EP2136982B1 patent drawingFigure 1
  • EP2136982B1 patent drawingFigure 2

AI summary

The present invention relates to a mold for producing molded skins 7 and molded bodies 7 made of plastic, wherein the mold is configured as a double-walled hollow body and comprises a shaping front wall 1 and a rear wall 2 in which hollow chambers 3 are formed. In this arrangement, energy and significant amounts of material can be saved with slush or rotation methods for producing molded skins 7 and molded bodies 7, particularly for interior trim and dashboards of motor vehicles.