Non-Permanent Mold Strata with Sacrificial Projections

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The fragility of models made from stacked strata in non-permanent molds, particularly those used in lost-wax casting, makes them prone to deformation during storage or handling, leading to unsatisfactory quality of the final parts due to damage from shocks or friction.

Innovation Solution

A set of strata is designed where non-functional projections are strategically taller than functional projections, allowing the non-functional projections to absorb shocks and friction, thereby protecting the functional projections from damage during storage and handling. This design involves stacking strata with recesses that cover non-functional projections when combined, preventing contact with refractory materials and ensuring the functional projections remain undamaged.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If models are made from stacked strata to simplify manufacturing, then ease of manufacture is improved, but the model becomes fragile and prone to deformation during storage or handling

Engineering Contradiction:
Improveease of manufactureVSAvoidmodel integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The model is divided into multiple strata that can be manufactured separately and then stacked together. This segmentation allows each layer to be produced independently using standard manufacturing processes, improving ease of manufacture while maintaining the ability to form complex 3D geometries when assembled.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Non-functional projections are added to the strata during manufacturing, before the stacking process. These projections act as preliminary protective elements that will absorb shocks and friction during subsequent storage and handling, preventing damage to the functional geometry of the model.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If non-functional projections are added to protect functional projections, then model integrity is improved, but device complexity increases

Engineering Contradiction:
Improvemodel integrityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The protective non-functional projections are added only at specific locations where shock and friction protection is needed, rather than uniformly across the entire model. This localized approach provides necessary protection while minimizing the increase in overall device complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The non-functional projections are designed as sacrificial elements that absorb damage during storage and handling. These projections are intentionally made as simple, easy-to-manufacture features that can be depleted or damaged without affecting the functional geometry, effectively serving as a low-cost protection mechanism.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 protects the functional projections from damage, ensuring the quality of the parts produced by non-permanent mold molding is maintained by absorbing shocks and friction with the taller non-functional projections, thus preventing deformation and maintaining the integrity of the mold.

Implementation Method 1

absorb shocks and friction

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

absorb shocks

Methodology Applied
Scientific EffectImpact Force: Impact Force

Implementation Method 3

recesses that cover non-functional projections when combined, preventing contact with refractory materials

Methodology Applied
Scientific EffectPhysical Containment: Physical Containment

Implementation Method 4

functional projection being a projection which is in contact with the refractory material

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2397245B1Set of strata, mould, methods for producing said model and for manufacturing a part using said model
Publication Date: 2018.11.21 PSA AUTOMOBILES SA
  • EP2397245B1 patent drawingFigure 1~2
  • EP2397245B1 patent drawingFigure 3~6

AI summary

The set of layers comprises a first layer (10), and a second layer to be stacked on the first layer in a direction of stacking. The first layer includes three non-functional projections (20, 21, 22) that extend in the direction of stacking and along non-colinear axis, and a functional projection (16, 18) with shield, where the functional projection is in contact with a refractory material when the two layers are stacked. The second layer comprises a recess capable of completely covering the non-functional projections when the two layers are stacked. The set of layers comprises a first layer (10), and a second layer to be stacked on the first layer in a direction of stacking. The first layer includes three non-functional projections (20, 21, 22) that extend in the direction of stacking and along non-colinear axis, and a functional projection (16, 18) with shield, where the functional projection is in contact with a refractory material when the two layers are stacked. The second layer comprises a recess capable of completely covering the non-functional projections when the two layers are stacked so as to prevent contact between the non-functional projection and the refractory material. A height of the non-functional projection in the direction of stacking is greater than a height of the functional projection in the same direction of stacking. Independent claims are included for: (1) a non-permanent mold; and (2) a process for making a model for manufacturing a part by a non-permanent mold made of refractory material.