Process Optimization of Industrial Solid Freeform Fabrication System

This paper presents experimental optimization of process parameters for a newly developed SFF(Solid Freeform Fabrication) system. Two critical process parameters, layering thickness and curing period, which have a large effect on the quality of the product, are optimized through experiments. Specimens are produced using layering thicknesses of 60, 80, 100, 120, 140, and 160㎛ and curing periods of 0, 10, 20, and 30 minutes under the same processing conditions, i.e., build-room temperature, feed-room temperature, roller speed, laser power, scan speed, and scan spacing. The specimens are tested to compare and analyze performance indices such as thickness accuracy, flatness, stress-strain characteristics, and porosity. The experimental result indicates that layering thickness of 80~100㎛ and curing period of 20~30 minutes are recommended for the developed industrial SFF syste

Optimal Layering Thickness for Industrial SFFS

The layering thickness affects quality of the products processed in the solid freeform fabrication system (SFFS) that uses selective laser sintering (SLS). It is broadly recommended that the layering thickness should be between 100 and 150 ㎛ if the average size of the powder particles is around 50 ㎛. In this paper, specimens are produced using varied layering thicknesses of 60, 80, 100, 120, 140, and 160 ㎛ under the same processing conditions, i.e., build-room temperature, feed-room temperature, roller speed, laser power, scan speed, and scan spacing. The specimens are tested to measure thickness accuracy, flatness, stress-strain characteristics, and peeling between the laminated layers. Optimal layering thickness for the developed industrial SFFS is recommended from the analysis

Temperature Control of Build-room for SLS Process of Industrial SFFS (Solid Freeform Fabrication System)

This paper presents a real-time temperature controller for the industrial SFFS. The SLS (Selective Laser Sintering) process of the SFFS requires the temperature of the powder surface to be maintained close to the melting point. But the build-room temperature should not exceed a set point to prevent the previously sintered part from curling. The developed SFFS has two independently controlled upper and lower heaters. The heaters are controlled through SCR (Silicon Control Rectifier) and SSR (Solid-State Relay) by the control PC

Optimal Process Control of Industrial SFFS

This paper presents the optimal process control of newly developed SFFS (Solid Freeform Fabrication System). The process control of SFFS consists of nitrogen supplement, temperature setting, powder laminating, and laser sintering. The temperature setting has three steps of preheating, sustaining, and cooling as the process progresses. Powder laminating and laser sintering are carried out sequentially when the temperature reaches the desired point. The process is controlled by a PC-based controller which also supports a user-friendly interface and easy access for the parameters setting