An important point when working with molds:
When using the mold, you must pay attention to the maximum working pressure. Different sizes of molds have different maximum working pressure. Please do not exceed it to avoid damage to the mold (the maximum working pressure will be marked on each mold of XYM)
Selection suggestion:
①If the sample is pressed thicker, or the rectangular sample and the powder that is not easy to form, in order to ensure the convenience of ejection and avoid damage caused by excessive friction when the sample is ejected, it is recommended to use a split XYM-K mold.
②If the fineness of the powder is very small, such as less than 50um, because the mold precision is very high and the work difference is small, it is easy to cause stuck pillars (top pillars), which makes it difficult to eject the mold after pressing the sample. At this time, the double gasket structure is generally used. At the same time, increase the work difference of the pressure column (the pressure column is relatively finer) to avoid the column jamming. In the same case, using the XYM-K flap opening mold will also avoid the column jamming phenomenon, and for the case where the powder fineness is very fine and difficult to form , open flap mold is also recommended priority.
Precautions for the use of cemented carbide molds:
XYM-ZP cemented carbide mold has a hardness above HRC88, good anti-rust and anti-oxidation ability, good effect of mirror polishing tablet pressing, more wear-resistant and pressure-resistant, longer service life, and can withstand greater vertical pressure. However, molds with high hardness have relatively poor toughness. They are afraid of bumping against hard edges and uneven force due to bending. Therefore, it is necessary to ensure that the force is vertical when pressing samples and ejecting molds.
Maintenance and preservation of the mold after use:
After each sample pressing, the mold cavity should be cleaned to avoid long-term non-cleaning, which will cause the powder to adhere to the cavity and cause the sample to be stuck. The cleaning methods can be washed with water, wiped with alcohol solvent, ultrasonic water, etc. and cleaned with a small brush or Clean the inner wall with a cloth (make sure the mold is dry after cleaning).
If the mold is not used for a long time, it is necessary to clean and dry the mold and then store it in a dry environment. If the environment is humid, it is recommended to apply lubricating butter or engine oil inside the mold for long-term storage to prevent surface oxidation.
Customer asked: What is the maximum working pressure that the mold can withstand?
The maximum working pressure of different sizes of molds is different, but the maximum pressure is basically the same. The maximum working pressure of our XYM series molds is basically 1200MPa, and then according to F=P×S, we will mark its maximum working pressure in tons. The customer can press the sample against the pressure of his own tablet press.
common problem
1. The customer asks: I want to use more pressure, can it be overpressured?
We do not recommend customers to use the mold with overpressure. Although a little overpressure may cause little harm to the mold, sometimes it is easy for customers to overpressure too much if they do not grasp it well, causing damage or even cracking of the mold. In addition, if the customer needs a lot of overpressure, it is recommended to order a solid carbide mold. The actual pressure of the solid carbide mold can reach 2500MPa.
2. The customer asks: Why is my pressure column shortened?
This kind of situation is caused by too much overpressure, and it is basically a small mold (within 13mm), because the mold pressure column is made of cemented carbide, and the pressure cap is generally quenched with 3Cr13 material. The hardness of the pressure cap is relatively low, and the toughness is good. The high-quality alloy pressure column plays the role of protection and buffer. When the overpressure is too high, the pressure column will squeeze into the pressure cap, so as to avoid the overpressure of the pressure column. Therefore, the pressure column becomes shorter. At this time, it is necessary to replace a set of pressure columns. up.
3. The customer asks: Can the mold be pressed into a thickness of 50mm?
The thickness of the mold pressure sample mainly depends on the depth of the cavity, the amount of powder placed and the compression ratio of the powder. For our XYM mold, we can achieve a maximum cavity depth of 100mm (it is recommended to press into a thickness of more than 10mm or not easy to form. The powder is pressed with a split mold structure), but the same amount of powder with different compression ratios will result in different thicknesses. If the compression ratio is large, you can fill the powder multiple times and manually pre-compact it with a pressure column each time. one time.
4. The customer asks : How thick can the thinnest mold be?
There is actually an upper limit and no lower limit for the thickness of the mold pressing sample, but it is also required that at least the powder needs to spread the bottom of the cavity evenly.
5. The customer asked: Why is it difficult to form after pressing the sample, and some will be layered?
①Because the pressure is too high and the sample is pressed too tightly, the powder expansion force is too large when ejecting the mold, which can reduce the pressure ②The pressure relief speed is too fast, causing the sample to suddenly expand, resulting in extrusion and cracking of the sample, it is recommended to loosen the pressure relief valve ③The physical properties of the powder itself will also affect the molding effect. You can consider changing the physical properties of the powder, such as adding binders, changing the particle fineness, etc. Generally, the smaller the fineness, the easier it is to form badly.
6. The customer asked: Why is there a loud sound when the mold is withdrawn?
Generally, it is because the powder sample is too thick, and the friction force is very large when the mold is ejected, and the sound of friction between the sample and the cavity occurs. Solution ① Clean the cavity, or apply a lubricant such as glycerin on the inner wall of the cavity to reduce friction. ②Using XYM-K flap-opening mold, the intima flap can be separated directly when the mold is withdrawn, and the effect of compression without friction is better.
7. The customer asks: When the heating mold is heated, will the pressure of the mold be affected?
Within 300 degrees, the basic influence is not great. It is recommended to reduce the mold pressure to less than two-thirds of the normal situation when the temperature is above 300 degrees and no more than 350 degrees. Repressurization above 350 degrees may cause damage to the mold structure. In this case, it is recommended to choose a high-temperature cemented carbide material.
8. The customer asked: Will the inner cavities of the flap mold be combined without powder leakage?
The combination precision of XYM-K flap-opening mold is very high, and the flatness and smoothness of the cavity used are no different from those of non-opening molds.
9. The customer asked: What is the use of some molds with vacuum nozzles?
Our XYM-ZP and XYM-Z mold structures are both equipped with vacuum nozzles. This structure is mainly used for small-sized molds, and they are all structures with gaskets. Function ①Because the precision of the mold fit is very high, if the gasket fits tightly and has an exhaust nozzle, it will be easier to put the gasket. ② Some experiments can be vacuumized.
