Powder Injection Molding Using Vibrational Energy for Complex Geometries

Solution Overview

Problem

Conventional ceramic injection molding (CIM) and metallic injection molding (MIM) processes face challenges with poor process stability, leading to surface defects and volume flaws in molded articles, particularly in complex geometries like dental implants or abutments.

Innovation Solution

The process involves heating a feedstock containing ceramic, metal, or metal alloy powder dispersed in a binder and injecting it into a mold cavity under the application of vibrational energy, which improves the filling of the mold cavity by reducing friction and viscosity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional PIM techniques are used to produce complex geometries, then the mold cavity can be filled, but surface defects and volume flaws occur due to high viscosity and imperfect filling

Engineering Contradiction:

Improvesurface qualityVSAvoidprocess stability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies ultrasonic vibration to the feedstock during injection molding to reduce its viscosity and improve flow behavior. This mechanical vibration enables complete filling of complex mold cavities while eliminating surface defects and volume flaws, thereby improving both surface quality and process stability simultaneously

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent changes the physical parameters of the feedstock by applying ultrasonic energy during injection, which temporarily reduces viscosity and enhances flow characteristics. This parameter change allows the feedstock to fill complex geometries completely without defects, resolving the contradiction between manufacturing precision and process stability

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If pre-heating of the mold is applied to improve feedstock flow behavior, then the injection window is prolonged, but the cycle time increases due to required cooling before demolding

Engineering Contradiction:

Improveinjection windowVSAvoidcycle time

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent replaces the thermal approach (pre-heating the mold) with a mechanical/physical approach (ultrasonic vibration of feedstock). This substitution achieves improved flow behavior and prolonged injection window without requiring mold temperature changes, thereby avoiding the cycle time penalty associated with heating and cooling the mold

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Shape

If conventional PIM is used for complex geometries, then molding is attempted, but poor filling occurs due to high viscosity

Engineering Contradiction:

Improvecomplex geometryVSAvoidmold cavity filling

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The patent applies ultrasonic vibration to the feedstock during injection molding to reduce its viscosity and improve flow behavior. This mechanical vibration enables complete filling of complex mold cavities while eliminating surface defects and volume flaws, thereby improving both surface quality and process stability simultaneously

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent changes the physical parameters of the feedstock by applying ultrasonic energy during injection, which temporarily reduces viscosity and enhances flow characteristics. This parameter change allows the feedstock to fill complex geometries completely without defects, resolving the contradiction between manufacturing precision and process stability

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 results in molded articles with decreased surface porosity and volume flaws, achieving an improved bend strength of 20% or more, even for complex geometries, without increasing cycle time.

Implementation Method 1

step c) is carried out under the application of vibrational energy onto the feedstock

Methodology Applied

Scientific EffectVibration: Vibration

Implementation Method 2

b) heating the feedstock

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentUS12240160B2Process for the preparation of an article by powder injection molding

Publication Date: 2025.03.04 STRAUMANN HOLDING AG

AI summary

A process for the preparation of an article by powder injection molding, the process including the steps of providing a feedstock containing a powder of a ceramic, a metal or a metal alloy dispersed in a binder, heating the feedstock, and injecting the heated feedstock into a mold cavity of a mold, where it cools and hardens to the configuration of the mold cavity. The process is characterized in that step c) is carried out under the application of vibrational energy onto the feedstock.