Crushing Samples in the X-Press
The X-Press is a motorized hydraulic press that crushes samples into smaller pieces.
First, clean the X-press with simple green and isopropyl alcohol. Clean the work area and materials with isopropyl alcohol for each sample.
Place a large KimWipe on your working surfaces for your clean materials. Next collect the following supplies that make up the 'crushing unit' of the X-press (Figure 6). Materials are located in the drawer labeled 'X-PRESS SUPPLIES' in the X-Ray Prep Area in the thin section lab.
- Weigh Paper 6" x 6"
- Core liner
- Two delrin discs
- Stainless steel base
- Aluminum Die
Figure 6: Materials needed for assembly of ‘crushing unit’. A. Weigh Paper 6”x6”. B. Core Liner C. Two Delrin Discs D. Stainless Steel Base E. Aluminum Die
...
- Grab the stainless steel dish. This is the base for the crushing unit (Figure 7).
...
- Place a piece of Weigh Paper on the Base (Figure 8).
...
- Put one Delrin disc on top of the weigh paper (Figure 9).
...
- Place the sample on top of the Delrin Disc (Figure 10). These discs can fracture leaving Teflon flakes in the sample so arrange the sample such that the two flattest surfaces are the top and bottom.
...
- Now place the second delrin disc on top of the sample (Figure 11). Again make sure the disc rests flat against sample.
...
- Put the aluminum die on top of the delrin disk, holding it until you slip the core liner over the unit (Figure 12).
...
- Now slip the piece of core liner over all the pieces and resting inside the stainless steel base (Figure 13). This contains the sample pieces inside the unit.
...
- The crushing unit is now assembled and we can start crushing samples (Figure 14).
Figure 14: Overview of the X-Press. A. Metal platform sample rests on B. Jacksrew C. Pressure Relief Handle. D. ‘On’ toggle E. Pressure Gauge.
...
Safety Note: Always wear safety glasses. Do not stand directly in front of the X-Press while it is operating. Never leave the X-Press unattended while using. Do NOT take the instrument above 10 tons of pressure.
After the sample has cracked remove the crushing unit. To remove the unit, loosen the 'pressure relief handle' by rotating it counter clock wise and press down on the toggle switch. The pressure gauge should read zero and the metal platform will lower down. Do not leave the platform up, always make sure to lower it back down after crushing a sample. When the platform is level with the surface let go of the toggle and start unscrewing the jackscrew. Then open the door and remove the unit. The pieces can be poured into a labeled bottle that will eventually hold the finely ground powder. From here the pieces will then be put into the Shatterbox vessels.
...
Grinding Samples in the Shatterbox
The shatterbox takes the crushed pieces from the X-Press and grinds them into a very fine powder. The Spex shatterbox is capable of grinding three standard size samples or one large sample. Our grinding vessels used are tungsten carbide.
Apparatus and Materials
- Shatterbox
- Tungsten Carbide Vessels: Vessel, Puck, and Lid
- Samples
- 1oz Sample Vials
- Sample Labels
...
Figure 15. Shatterbox. A. Power switch. B. Cover. C. Control panel
...
Figure 16. Small vessel components. A. Container B. Puck. C. Lid
The large grinding vessel holds between 20 – 60mLs of material and has five components: a container, puck, inner ring, O-Ring and lid (Figure 17).
...
Figure 17. Large Vessel components. A. Container B. Inner Ring C. Puck D. O-Ring E. Lid
...
Figure 18. Three-pinned rack plate to hold three small vessels in Shatterbox
Figure 19. Single-pinned rack plate to hold one small vessel in Shatterbox
The three-pinned plate will hold three vessels while the one-pinned plate will only hold one. If two samples need to be crushed select the three-pinned plate. The large vessel will sit directly in shatterbox without an additional plate below it.
Loading the Shatterbox
Transfer the sample pieces into the grinding vessel. Pour sample pieces between the puck and the wall of the vessel (Figure 20). There can't be any material on top of the puck or inside the sealing ring; otherwise the vessel will not seal properly and the sample can spill inside the shatterbox. If any pieces are on top of the puck or ring, use gloves, tongs, or a KimWipe to move the sample into the vessel. Put on the lid and start assembling the shatterbox.
Figure 20. Small vessel filled with sample pieces. No sample material is on the top the puck or in the lid ring.
...
Figure 21. The inside of the Shatterbox. A. The lever arm B. The clamp arm C. The inner capsule
...
Figure 22. Inside the Shatterbox with the bottom three-pinned rack plate resting inside the inner capsule.
Now load vessels onto the plate (Figure 23). The divet in the bottom of the vessels will settle onto the pins and fit firmly in place.
Figure 23. Three samples loaded into the Shatterbox.
...
Figure 24. The top rack plate sitting on top of the three samples. A. Clamp arm. B. the “boss” of the rack plate, where the clamp arm will attach.
...
Figure 25. A. The lever arm inserted into the end of the clamp arm. B. The clamp arm pushed over the lever arm.
The resistance in the lever arm is very important and must be adjusted before use. There should be moderate resistance in the arm while pushing it down. If the resistance is too low the containers can shake free; whereas, if it's too strong the clamp can break. Ideal tightness is just past the point where the vessels can be rotated while the clamp is down. Adjust the resistance by raising the clamp arm and pushing on the 'locking pin.' Hold the locking pin and turn the guide (Figure 26A). Rotating the guide clockwise decreases resistance; whereas counterclockwise increases resistance.
Figure 26. The lever arm and the guide. A. Retractable locking pin being pushed to allow adjustment of the 'guide' length.
...
Figure 27. A. Current operating time. B. Minute button. C. Second button. D. Start button. E. Pause/Stop button.
...
Normal Sounds: The shatterbox is extremely loud. The foam and strap surrounding the shatterbox helps keep it in place and minimize some of the noise.
Abnormal Sounds. If there are any metal on metal sounds shut off the shatterbox immediately. Something inside the shatterbox has probably come loose and will damage the inside of the container.
When the shatterbox cycle is done open the lid and remove the vessels, placing them on the counter. Open the grinding vessel and with clean tweezers take a bit of the powder and feel it against the inside of your wrist. The sample should feel like baby powder, if it does not, repeat the shatterbox cycle.
Transfer powder into Vial
Disassemble the vessel carefully wearing 'Powderless Nitrile' gloves. Clean off any powder on the lid or puck with clean gloves or a Kim Wipe. Carefully remove the puck from the vessel. Pour the sample onto a clean weighing paper. If any powder remains, use a clean plastic spatula, brush, or your finger to dislodge it.
Note: Never use metal to dislodge sample material, as any grooves or scratches in the vessels will increase the risk of contamination.
Cleaning the Grinding Vessels
Vessels must be cleaned in between samples and after all samples have been run for the day. Vessels should never be put away wet. This alters and tarnishes the vessel.
In Between Sample Runs
- Wearing nitrile gloves, wash the individual pieces of the grinding vessels with DI water and a small piece of a scouring pad (no soap).
- After each washed piece piece immediately spray it with isopropyl alcohol and wipe it down with a Kim Wipe. Do not use the ship's compressed air line to dry pieces as the air is too dirty.
- Lay the pieces on, and cover vessels with Kim Wipes.
After the last run for the day
1. Take a scoop of quartz sand and put it in your vessel and run it as you would a sample for several minutes.
2. Remove the vessel and empty out the sand. Scrub the pieces with DI water and a scouring pad. Then spray with isopropyl alcohol and wipe down with Kim Wipe.
If your vessel is particularly dirty run a combination of quartz sand, a little hot water and detergent (Borax). This can be run for several minutes. A thick paste will form and you clean it with DI water and isopropyl as in the other cases.