Selective Sintering via Variable Radiation Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current rapid prototyping methods using laser sintering are time-consuming, and infrared radiation methods often result in unsatisfactory accuracy due to the need for uniform radiation exposure across entire layers of particulate material.
Innovation Solution
A method and apparatus that vary radiation absorption across selected surface portions of particulate material layers using controllers, obscurers, and radiation transmissive substrates with varying reflective materials or radiation absorbent materials to control the intensity and distribution of radiation, allowing for selective sintering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser sintering is used to combine particulate material, then the particulate material can be selectively combined, but the process is time-consuming because the laser must pass over the entire surface of each layer
Solution Approach 1:
The radiation source is divided into multiple independent radiation elements (e.g., LED arrays, laser diodes) that can be individually controlled. This segmentation allows only the required portions of the layer to be exposed to radiation, eliminating the need to scan the entire surface and significantly reducing processing time while maintaining selective combining capability.
Solution Approach 2:
The particulate material is pre-coated with a binder material before radiation exposure. This preliminary action enables the material to be selectively combined without requiring the radiation source to traverse the entire layer, as the binder facilitates targeted bonding at specific locations where radiation is applied.
2Productivity
If infra-red radiation is provided on selected portions of a layer to combine it, then processing time is reduced, but the accuracy of the components produced is unsatisfactory
Solution Approach 1:
Different regions of the layer receive different radiation intensities and exposure times through independently controllable radiation elements. The controller adjusts parameters locally for each radiation element based on the specific requirements of that region, enabling precise control over combining characteristics and maintaining high component accuracy while processing only selected portions.
Solution Approach 2:
The system varies radiation parameters (intensity, wavelength, exposure duration) across different locations and depths of the layer. By dynamically adjusting these parameters, the system achieves accurate selective combining in reduced time, as each region receives optimized radiation conditions tailored to its specific combining requirements.
3Device complexity
If uniform radiation exposure is applied across entire layers, then the combining process is simple, but thermal gradients and shrinkage increase
Solution Approach 1:
Instead of uniform radiation exposure, the system applies localized radiation with varying intensities to different regions of the layer. The controller manages this non-uniform exposure by independently controlling multiple radiation elements, achieving accurate dimensional results while minimizing thermal gradients and shrinkage without excessive complexity.
Solution Approach 2:
The system incorporates feedback mechanisms to monitor and adjust radiation exposure in real-time. By measuring actual combining results and thermal conditions, the controller modifies radiation parameters to compensate for thermal gradients and shrinkage, maintaining dimensional accuracy while managing the complexity of non-uniform radiation control.
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 enables efficient and accurate combination of particulate materials by controlling the sintering process, achieving good material properties and edge definition while minimizing thermal gradients and shrinkage.
Implementation Method 1
infra-red radiation can be provided on selected portions of a layer of particulate material to combine it
Implementation Method 2
a laser that sinters the particulate material
Implementation Method 3
varying the absorption of the provided radiation across a selected surface portion of the layer to combine a portion of the material
Data Source
AI summary
A method of selectively combining particulate material, for example plastics material by sintering, comprises providing a layer of particulate material, providing radiation, for example using a radiation source over the layer, and varying the absorption of the provided radiation across a selected surface portion of the layer to combine a portion of the material of the layer. The method may comprise varying radiation absorption by varying the intensity of the radiation incident on the surface portion of the layer, or alternatively may comprise varying the radiation absorptive properties of the particulate material over the selected surface portion of the layer, for example by printing a radiation absorbent material onto the surface portion.