1、 Bonding of petrographic samples


Use MetLab's medium-sized METCUT-10 or large METCUT-12A, or even 20A grinding wheel cutting machine to uniformly cut large-sized petrographic samples to the length, width, and thickness suitable for the glass slide.


Alternatively, using MetLab's lithofacies precision cutting and grinding integrated machine METCUT-10GEO, replace the vacuum chuck with a mechanical fixture (the T-slot of the workbench is 8mm, so the T-slot of the fixture must be equipped with 8mm), fix the lithofacies sample, shake the cutting handwheel, cut along the Y-axis (longitudinal), and cut the desired thin piece.


On a flat grinding stone, grinding disc, thin film, or sandpaper made of suitable materials (such as alumina, silicon carbide, diamond, etc.), a matte surface is pre ground on the non research surface of the cut petrographic sample to create a surface that is bonded to the glass slide.


Lay a piece of grease film or paper on the workbench. Remove the slide. If multiple samples are prepared simultaneously, arrange glass slides with the same length, width, and thickness. There are many sizes of glass slides, commonly used as 27x46mm, which matches the size of the vacuum chuck of the lithofacies precision cutting and grinding integrated machine.


It is recommended to use QMAXIS (Kemai) epoxy resin and curing agent as the bonding agent&flash& Flash; Among them, the rock facies samples without pores were obtained using the EpoQuick series; For samples with pores, the EpoFlow series&flash& Flash; Mix according to the proportion indicated on the label, pour into a mixing wax paper cup, and slowly stir for about 2 minutes with a stirring rod.


The first example describes a petrographic sample without pores. Apply the mixed EpoQuick epoxy resin and curing agent evenly to the non study surface of the petrographic sample, and then place them on a glass slide. Gently move and squeeze back and forth to remove all bubbles. Scrape off the extruded epoxy resin on the glass slide with a stirring rod.


Place the bonded petrographic samples on the thin sample bonding platform METBOND GEO, compact them with compression springs, and let them stand for about 2 hours. METBOND GEO is a thin sample bonding table with a heating plate. In order to accelerate the resin curing speed, the heating switch can be turned on and the temperature can be set on the control panel. If MetLab's METBOND GEO&flash; is not configured& Flash; That is to say, a thin sheet bonding table without a heating plate&# 8217& Flash; Thin sample bonding table can be placed at 60 ° C; Heat on a hot plate around C or naturally cure at room temperature.


● Of course, the bonding agent can also be the mounting adhesive Hot-melt adhesive of QMAXIS (Kemai). Place the glass slide and the petrographic sample (the non research side up) on the heating table. When heated to 100-120 ℃, use a Hot-melt adhesive stick to evenly coat the non research side and the glass slide of the petrographic sample. Observe that the Hot-melt adhesive has completely melted, stick the non research side of the petrographic sample to the glass slide, move it to the thin sample bonding table, and stand after compaction

● Mount the sample. Click on the vacuum switch (2) on the cutting side of the main menu, attach one side of the glass slide that has been bonded to the lithofacies sample to the surface of the vacuum chuck, and the vacuum chuck will suck on the glass slide. A small-sized vacuum chuck with three protruding screws to assist in confirming the position of the small-sized glass slide.


● Positioning the cutting position. The vacuum chuck on the cutting side is installed on the chuck seat on the workbench, and the micrometer knob is used to drive the workbench to move left and right along the X-axis (transverse). The micrometer knob has a scale of 0.005mm and moves 1mm by rotating it once. The total travel of the X-axis is 20mm, which meets the thickness adjustment of any thin sample. By using the micrometer knob, maintain the correct left and right distance between the sample and the cutting piece, i.e. locate the desired cutting position.


Close the cutting chamber protective cover. The magnetic safety switch of the protective cover locks the protective cover.


Set the cutting blade speed (4) on the touch screen control panel. The speed is 100-3000rpm/min, with an increment of 1rpm/min. You can click the arrow to adjust up and down, or you can use the Numeric keypad to enter the revolution value. Click on the cooling water switch (5) on the cutting side, the cooling water flows out, press the cutting/grinding switch (1), and the motor drives the diamond cutting blade to rotate.


● Manual control of cutting. Shake the cutting handwheel clockwise at a uniform speed, and the entire workbench gradually approaches the cutting blade along the Y-axis (longitudinal) direction to start cutting. The total travel of the Y-axis is 224mm, which meets the length direction of all standard slide sizes. The advantage of manual control is that the user has a large degree of freedom to control, and the cutting of thin films with different materials and preparation requirements can be adjusted independently.


The minimum retained thickness for sample cutting is about 0.5mm.


After the cutting is completed, click the cutting/grinding switch (1) and the cutting side cooling water switch (5) again to stop the rotation of the cutting motor and turn off the cooling water. Rotate the handwheel counterclockwise to remove the sample from the diamond cutting blade.


Open the door of the cutting chamber, click on the vacuum switch (2) on the cutting side, and the vacuum pump will be turned off. Take the downloaded glass slide from the vacuum chuck and remove the cut sample from the cutting chamber workbench.


Wash the slide and sample with water and prepare for grinding.



3、 Grinding of petrographic samples


Similarly, install the diamond cup grinding wheel before starting the machine. The diameter of the diamond cup shaped grinding wheel is 10 inches (250mm), and the axis diameter is 1.25 inches (31.75mm). The standard diamond cup grinding wheel configuration is 70 μ M and 30 μ M's. Usually, from coarse to fine grinding, install a 70% removal amount first μ M's. Open the protective cover of the right-hand grinding chamber of METCUT-10GEO upwards. Use a random tool to remove the flange of the spindle, insert a diamond cup shaped grinding wheel (with the diamond grinding surface facing outward), re tighten the flange, and lock the nut.


Turn on the main switch of METCUT-10GEO. Similarly, touch any position on the Logo page to enter the main menu page for operation.


● Mount the sample. The vacuum chuck on the grinding side is fixed on the coaxial grinding arm of the grinding operation handle. The grinding handle is outside the grinding chamber, and the grinding arm is inside the grinding chamber. click