Low-Temperature Sintering Polymer Substrate Fusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional selective laser sintering (SLS) methods require high temperatures and strict temperature control, making them costly and time-consuming, and are not suitable for processing temperature-sensitive polymers, as they necessitate heating the powder bed above the crystallization temperature, leading to potential distortion and thermal ageing of unconsolidated powder.
Innovation Solution
The method involves using a solid substrate within the processing device for additive layer manufacturing, where a first layer of polymer powder is fused onto the substrate at a desired location using an energy source, allowing for the formation of articles at low temperatures, such as room temperature, without the need for preheating the powder bed, and subsequent layers are deposited and fused successively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the powder bed is heated above the crystallization temperature in conventional SLS, then the polymer particles can be fused properly, but the unconsolidated powder undergoes thermal ageing and cannot be recycled
Solution Approach 1:
The substrate is prepared in advance with a surface treatment or coating that enables direct fusion of polymer particles at low temperatures, eliminating the need for high-temperature preheating of the entire powder bed. This preliminary preparation allows particles to be fused reliably without thermal ageing.
Solution Approach 2:
The substrate acts as an intermediary between the energy beam and the polymer particles, concentrating and directing energy to facilitate fusion at lower temperatures. This intermediary effect enables reliable fusing without requiring the entire powder bed to be heated to high temperatures that would cause thermal ageing.
2Reliability
If high temperatures are applied in conventional SLS, then polymer fusion is achieved, but temperature-sensitive polymers cannot be processed
Solution Approach 1:
The process parameters are changed from high-temperature bulk heating to low-temperature localized fusion. By changing the temperature parameter and the heating method (from conventional SLS to substrate-based fusion), temperature-sensitive polymers can be processed while maintaining reliable fusion quality.
3Reliability
If the powder bed is heated to above crystallization temperature, then proper sintering occurs, but processing time and energy consumption increase
Solution Approach 1:
The heating function is extracted from the powder bed and transferred to the substrate. Only the substrate and the specific fusion zone are heated to the necessary temperature, rather than heating the entire powder bed. This extraction of the heating function to a localized area reduces processing time and energy consumption while maintaining sintering quality.
4Manufacturing precision
If strict temperature control is maintained in conventional SLS, then article distortion is prevented, but processing complexity and cost increase
Solution Approach 1:
The substrate serves as a thermal mediator that absorbs and distributes heat locally, reducing the need for complex temperature control systems. The substrate's thermal properties help maintain dimensional accuracy without requiring the elaborate temperature control infrastructure needed in conventional SLS.
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 the production of articles without curling and reduces processing costs by allowing for low-temperature processing, enabling the use of temperature-sensitive materials and eliminating the need for extensive heating, thus improving efficiency and material versatility.
Implementation Method 1
fusing the first (co)polymer onto at least a part of the substrate at a desired location to deposit a first layer of the first (co)polymer onto the substrate by applying energy generated by at least one energy source of the manufacturing device to that location
Data Source
AI summary
An additive layer manufacturing method, preferably using selective laser sintering, for manufacturing a solid article, the method including applying a layer of a powder, the powder including at least one powdered (co)polymer, onto a solid substrate in a processing chamber; fusing the powder layer onto the solid substrate; subsequently depositing successive layers of the powder, wherein each successive layer is selectively fused prior to deposition of the subsequent layer of powder so as to form the article. In some embodiments, the powder further includes abrasive particles having a hardness greater than or equal to that of aluminum oxide.