The good solutions for 6 major problems in vacuum casting
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The good solutions for 6 major problems in vacuum casting
1> The silicone mold has a short lifespan
In the process of making the silicone mold, too much silicone oil is added, and the silicone oil destroys the molecular weight of the silicone, so the mold will be turned over less frequently and not durable. If it is said that small products with complex patterns are used to open the mold with silicone with high hardness, there will be a phenomenon that the number of mold turning is less, because the time when the silicone is too hard will be very brittle and easy to break. On the contrary, if you make a large product and use a silicone with a low hardness as a mold, the result will also be unsatisfactory. Because the silicone is too soft, its tensile force and tear strength will be reduced, and the resulting mold will be deformed, so the number of overturning will be reduced. The quality of the mold glue itself is very good, and the silicone is not good or bad, only suitable and unsuitable. This situation will not occur if we use silica gel suitable for the hardness of the product to make the mold.
2> Burn-in phenomenon occurs
Because unsaturated resin and resin products are added with peroxide curing agent, they will generate a lot of heat when they react with the resin. Generally, the curing time of resin is 3 minutes, so it is necessary to release the mold as soon as possible after 3 minutes to prevent the silicone mold from not being damaged. The phenomenon of mold burning occurs.
Filling mold of complex mold liquid silica gel and production method of slicing mold
3> Appears dry on the outside
Mold silica gel is a condensed silica gel, which is cured by absorbing moisture in the air. In the process of making silica gel, the moisture is evaporated to dryness without adding an appropriate amount of moisture. This phenomenon will occur. . Solution: This phenomenon is not a product quality problem, but because the water is not controlled, the storage period of the silica gel is increased, and the shelf life is long, and some phenomena will occur. As long as the silica gel is used, an appropriate amount of 0.05% water is added and stirred evenly. Some situations can be resolved.
4> There is a difference in tension
In the process of making the mold, in order to reduce the viscosity of the silica gel and make the silica gel easy to handle, a large amount of silicone oil is added to the silica gel, which will make the silica gel very soft, resulting in inability to pull and reduce the tear strength. The phenomenon of poor tensile force, resulting in the phenomenon that the mold is not durable, the service life is short, and the number of mold overturns is small.
The mold silicone itself will not emit oil. The oil is caused by the addition of composite silicone oil (complex of silicone oil and white mineral oil) during the operation, because white mineral oil is a petrochemical product, not silicone oil.
5> The mold is not resistant to acid and alkali, not resistant to aging.In the process of making silicone molds, we recommend that customers do not add any silicone oil. If necessary, the amount of silicone oil added should not exceed 5% to 10%. Because the addition of too much silicone oil will destroy the molecular weight of the silica gel, the resulting mold will not be resistant to acid and alkali, and is not resistant to aging.
6> There are traces, streaks, unevenness, etc. on the surface of the mold
This phenomenon occurs because the product or model to be reproduced has not been ground or polished. Because the actual model or product itself is not smooth or perfect enough, if the product or model to be replicated has not been ground or polished, even the best silicone mold will be unsightly and not smooth enough. Another situation is that when the release agent is applied, the mold will not be smooth if it is not evenly brushed.
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B Block,No 21,Nan Xing Three Street,Nan Fang Industrial Park,
Bei Ce,Humen,Dong Guan,Guang Dong,China.
Skype: Deepmould
Tel:86-15024107707
