Acetone Polishing of ABS Test Results

Transcription

1 Acetone Polishing of ABS Test Results Date: Objective: June 16, 16 Determine Effect of Acetone on Mechanical Strength of 3D Printed Objects in Different Print Orientaions. Equipment: TestrBot, PrintrBot, Digital Calipers, Digital Scale, Procedure & A total of 12 specimens were tested. (4 conditions were tested with 3 specimens representing Test Method: each variable.) 6 specimens were printed in the 'side' orientation, while the other 6 specimens were printed in the 'vertical' orientation. 3 specimens from each orientation were treated with an acetone vapor polishing process and allowed to dry out for 72 hours. (3 hours of this time was spent in a dehydrator.) All other variables were held constant. s were tested via loading at constant displacement rate in 4 Point Bend configuration until failure occurred. Conclusions & The result of static stress testing to failure has shown that acetone treatment has two measurable Discussion: effects on ABS 3D printed parts: 1) A chemical weakening of the material structure 2) A mechanical strengthing of layer bonds via the reduction of surface stress concentrations. This testing has shown that effect #1 outweights effect #2 to decrease the part strength by 9% in all stress conditions other than Z-axis loads, where effect #2 outweights effect #1 to increase the part strength by 31%. Regarding effect #1, these new results agree with previous testing done (by me) in effect but not in magnituide. My hypothesis is that the additional drying time that I gave the new specimens helped remove all traces of acetone which may have contributed to additional softening of the specimens in the previous testing. The overall effect of Acetone vapor polishing on ABS effectively makes parts more isotropic. That is, they react more uniformly to applied loads from various driections by sacrificing strength in their strong axis to increase strength ion their weak axis. Photo 1: Test Setup

2 Photo 2. s & Measurement Equipment Photo 3. Close Up of Representative s Photo 4. Printing In Horizontal Orientation Photo 5. Printing In Vertical Orientation

3 Normal, Horz Treated, Horz Normal, Vert Treated, Vert Avg Avg Stress (psi) Avg Stiffness (lb/in) Avg Ult Avg Ult Disp (in) Avg Ult Stress (psi) Avg Mass (g) Avg Ult Stress/W eight (psi/g) Avg Stiffness per weight,(lb /in) N/A N/A N/A N/A % (lb) 2% Stress (psi) Stiffness (lb/in) Ult Load (lb) Ult Disp (in) Ult Stress (psi) Mass (g) Std dev Ult Stress/W eight (psi/g) Stiffness per weight,(lb /in) Normal, Horz Treated, Horz Normal, Vert N/A N/A Treated, Vert N/A N/A

4 1 1 4 Point Bend ID: 1 ABS, Horizontal, Untreated % : lb 2% Stress: psi Stiffness: lb/in Load: lb Displacement at :.3532 in Bending Stress: psi Point Bend ID: 2 ABS, Horizontal, Untreated % : 14.7 lb 2% Stress: psi Stiffness: lb/in Load: lb Displacement at :.3151 in Bending Stress: psi

5 1 1 4 Point Bend ID: 3 ABS, Horizontal, Untreated % :. lb 2% Stress: psi Stiffness: lb/in Load: lb Displacement at :.2571 in Bending Stress: 59.6 psi Point Bend ID: 4 ABS, Vertical, Untreated % : N/A lb Stiffness: lb/in Load: lb Displacement at :.119 in Bending Stress: psi

6 1 1 4 Point Bend ID: 5 ABS, Vertical, Untreated % : N/A lb Stiffness: lb/in Load: lb Displacement at :.825 in Bending Stress: psi Point Bend ID: 6 ABS, Vertical, Untreated % : N/A lb Stiffness: 58.8 lb/in Load: lb Displacement at :.1296 in Bending Stress: psi

7 1 1 4 Point Bend ID: 7 ABS, Horizontal, Treated % : lb 2% Stress: psi Stiffness: lb/in Load: 14.7 lb Displacement at :.3211 in Bending Stress: 52.5 psi Point Bend ID: 8 ABS, Horizontal, Treated % : 87.9 lb 2% Stress: psi Stiffness: 2.8 lb/in Load: lb Displacement at :.353 in Bending Stress: psi

8 1 1 4 Point Bend ID: 9 ABS, Horizontal, Treated % : 83.1 lb 2% Stress: 46.7 psi Stiffness: 39.1 lb/in Load: lb Displacement at :.2486 in Bending Stress: psi SPECIMEN 9 NOT ADDED TO AVERAGE DATA BECAUSE IT DID NOT ACTUALLY FAIL. THE SPECIMEN ENDED UP FALLING OVER BUT DID NOT BREAK Point Bend ID: 1 ABS, Vertical, Treated % : N/A lb Stiffness: 4.5 lb/in Load: lb Displacement at :.1669 in Bending Stress: psi

9 1 1 4 Point Bend ID: 11 ABS, Vertical, Treated % : N/A lb Stiffness: lb/in Load: 58. lb Displacement at :.13 in Bending Stress: psi Point Bend ID: 12 ABS, Vertical, Treated % : N/A lb Stiffness: lb/in Load: lb Displacement at :.1 in Bending Stress: psi