Week 2¶
In this week I specified testing procedure and necessary tools for testing adhesive quality.
Bond strength test (tensile strength)¶
Tensile strength test is one of the common ways to test bonding strength of adhesives. Our goal is test maximum tensile strength which is the maximum strength divided per surface area (perpendicular to the tension force direction) that object (adhesive) can withstand before failure.
Suggested Tools
- Clamp stand
- Slotted weight
- Digital weighing balance
- MDF Specimens
Fab Lab focuses on designing necessary tools instead of purchasing them. Clamp stand and testing MDF specimens are designed in Fab Lab and printed using CNC machine.
Clamp Design¶
Clamp stand is used to hold testing specimens. Fusion 360 is used to design it.
Project sketches and save them in DXF format. DXF is 2D vector format. DXF files are sent to special software which converts them to gcode format. gcode format is what machine understand.
Cutting design using CNC machine
Final design
click here to download stl file
click here to download dxf base file
click here to download dxf pole file
click here to download dxf holder file
MDF specimens design¶
Tasting specimens are also designed in fusion 360. These specimens are attached together using casein adhesive.
Shapes are splitted after using offset plane and split body tools because, fusion had a software bug and saving dxf after projection was not possible.
click here to download stl file
click here to download dxf specimen 1 file
click here to download dxf specimen 2 file
Testing specimens on clamp stand
Water resistant test¶
In this test normal water from tap will be used. Distilled water won’t be needed since this testing procedure focuses on real case scenario.
Fire test¶
Lighter will be used to heat samples of adhesives to check if material is flammable.
Moisture test¶
If material is effected by water it is suggested to do moisture test. This test will be done in a room (i.e., bathroom) at different humidity levels (i.e., 0-20-50-80 %). Air humidifier and hygrometer will be used to take measurement.