Today we will introduce the principles and matters needing the attention of ceramic foam filter.
Ceramic foam filters can be placed in the gating system: sprue cup, sprue end, runner, inner runner.
1. The closer the placement position is to the casting cavity, the better it is to reduce the probability of secondary oxidation.
2. The design of casting system is better to be simple, without considering other slag retaining measures, so as to improve the utilization rate of sand mold and process yield rate.
3. The working area of the filter should be 4-6 times of the flow resistance section of the pouring system to ensure that the pouring speed is not affected.
4. According to the type of casting alloy and pouring temperature, choose the corresponding filter, should not be used over temperature.
5. Choose the right aperture, really play the filtering effect.
6. No filter can be used to control and influence the pouring speed.
Here are a few points to note in the use of foam ceramic filters.
1. In order to ensure that the liquid metal is fully filtered, the foundry ceramic filters must have a certain pressure head to overcome the obstacles of surface tension. The size of the indenter has a considerable effect on the start of filtration, generally should be greater than 300 mm, the indenter of casting should be correspondingly larger.
2. The lap part of the ceramic foundry filter and the casting should be sealed as far as possible to prevent the loss of metal liquid from the gap and not play the filtering effect. For some sand such as wet type, the use of ceramic foam filter alone is easy to place the part of the filter sand off, so it is necessary to design a filter seat to support the filter, so that the filter does not move under the impact of metal liquid, to prevent sand into the cavity and metal liquid loss.
3. The ceramic foam filter should be blown off the dust and internal fragments with compressed air before use, to avoid contamination of metal liquid impurities.
4. transportation, storage to avoid moisture, should be stored in a dry environment, if necessary before use to bake, so that the filter fully dry.
5. In addition, filters are fragile products, handling should be handled with care to prevent damage.