Full Color High Definition Fused Filament Fabrication

Full Color High Definition Fused Filament Fabrication

Botterman, B.

Babuska, R. (mentor)

Mechanical, Maritime and Materials Engineering

Delft Center for Systems and Control (DCSC)

2016-08-26

Although Full Color (FC) High Definition (HD) Additive Manufacturing (AM) machines are available on the market today, a FC HD Fused Filament Fabrication (FFF) printer has yet to enter the competitive FFF market. Leapfrog, a FFF printer manufacturer, holds a patent that allows the application of coating on 3D printed FFF filament after it has been deposited. In this thesis work a prototype has been realized that serves as proof of the FC HD FFF concept and forms the basis of the commercial product which will be launched in the near future. Using inkjet technology high development costs can be avoided if existing coating devices are used in the machine. The challenges are to achieve a maximum outer surface coating of the 3D printed object and minimize the time it takes to coat a 3D printed object. This time is increased dramatically by applying a coating layer after every 3D printed layer compared to no coating. Using the prototype machine several coating methods have been explored of which the most promising method is perpendicular coating. Here, after 3D printing a layer, droplets are jetted onto the outward facing surface of the object. The total coating time is minimized by grouping contours which can be coated in one swath and sorting the order in which groups are coated. The grouping is done by formulating and solving a bin packing problem. Mixed Integer Linear Programming (MILP) and First Fit Decreasing (FFD) are compared and used to solve the problem, achieving more than 80% time reduction compared to no grouping on test models. A minimal movement time between all the groups is found by solving a Traveling Salesman Problem (TSP). The state of the art solver Concorde (CC) is compared to a Nearest Neighbor (NN) heuristic. A movement time reduction of 55% up to 85% is achieved compared to the standard 3D printing order on the test models. CC gives a maximum improvement of 2.3% over NN. The perpendicular coating method will be used to coat the filament. A significant total print time reduction is possible by grouping. MILP can have a hard time finding a solution for certain data sets, therefore FFD is preferred. For movement time reduction, a 2.3% performance increase by CC generally means that printing times are reduced by seconds. This is negligible considering 3D printing a layer generally takes minutes making NN a suitable heuristic for solving the TSP.

Traveling Salesman Problem
Nearest Neighbor
Variable Size Bin Packing Problem
First Fit Decreasing
Mixed Integer Linear Programming
3D printing
Additive Manufacturing

http://resolver.tudelft.nl/uuid:86dd172a-ef16-4df9-bee3-9c2026f4554a

2017-08-26

Student theses

master thesis

(c) 2016 Botterman, B.