Hollow 3D Object Thread Support Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in 3D printing hollow objects lies in the difficulty of removing support structures from complex cavities, particularly in convoluted or narrow openings, where traditional methods like water jets or corrosive liquids are inefficient.
Innovation Solution
A method is developed to create internal support structures within hollow 3D objects by computing a skeleton, defining a central line, and filling the object with a thread-like support material that can be easily pulled out, accompanied by a filling material with lower tensile strength, allowing for efficient removal without tearing or knotting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional support removal methods (water jets, corrosive liquids) are used, then support structures can be removed from hollow objects, but the process becomes inefficient and complex especially in convoluted or narrow openings
Solution Approach 1:
The support structure is segmented into a thread component and filling material component. The thread is designed as a discrete, pullable element that can be extracted independently from the filling material, allowing systematic removal without complex fluid dynamics or chemical processes.
Solution Approach 2:
The thread support structure is extracted as a separate removable component from the hollow object. The thread is designed with sufficient strength to be pulled out manually or mechanically without tearing, while the filling material is left behind or easily removed separately, simplifying the overall removal process.
2Ease of operation
If a thread support structure is used, then the thread can be pulled out without tearing or knotting, but the thread must be designed with specific tensile strength and geometric properties
Solution Approach 1:
The thread is designed with specific parameters including minimum tensile strength (50 N), curvature radius (at least 0.5 times the thread diameter), and winding patterns that prevent knotting. These parameter specifications ensure the thread can be pulled out easily while maintaining structural integrity during extraction.
Solution Approach 2:
The thread is designed with smooth curvature radii that are at least 0.5 times the thread diameter to prevent sharp bends that would cause knotting during extraction. The spiral or winding geometry is optimized to maintain continuous curvature without abrupt changes, facilitating smooth pull-out.
3Ease of manufacture
If filling material with lower tensile strength is used, then the filling material can be removed easily with the thread, but the filling material must be distinguished from the thread material
Solution Approach 1:
Different materials are used for the thread and filling material to create local quality differentiation. The thread material has high tensile strength (at least 50 N) for easy extraction, while the filling material has lower tensile strength for easy removal. This material differentiation is implemented through material selection during 3D printing.
Solution Approach 2:
The support structure uses composite material construction with distinct materials for the thread and filling material components. The thread uses a strong material (such as nylon or polyamide) while the filling material uses a weaker material, creating a composite structure that enables differential removal based on material properties.
Data Source
AI summary
Methods, particularly automated methods, are provided, as well as 3D-printed composite and hollow objects and 3D-printing systems for printing them. Methods comprise deriving a central line of a hollow 3D object model, calculating reference point(s) and/or line(s) along an inner surface of the hollow 3D object model, and filling the hollow 3D object model with material that comprises a thread defined with respect to the central line and the reference point(s) and/or line(s) and with filling material surrounding the thread. The support construction thus formed may be removed from the 3D object by pulling on the thread, extracting it and the surrounding support filling from the hollow object, thus enabling 3D-printing of convoluted or elongated hollow objects and objects with narrow openings. The parameters of the thread, such as type of curve and thickness, are selected to ensure thread extraction without risk of tearing or knotting the thread.