What should I pay attention to in vacuum casting ?

scanning:156 author:John Kino time:2019-09-19 classify:Industry News
1. What should I do if there are many bubbles in the mold silicone during the mold opening process? This condition should be treated according to the conditions. Under the condition of vacuuming machine, the silica gel and the curing agent should be mixed first and then vacuumed. If there is no vacuum machine, the amount of curing agent can be appropriately reduced for treatment. For example, the ratio of the original silica gel to the curing agent is 4%, and can now be changed to 1% to 2%.

1. What should I do if there are many bubbles in the mold silicone during the mold opening process? This condition should be treated according to the conditions. Under the condition of vacuuming machine, the silica gel and the curing agent should be mixed first and then vacuumed. If there is no vacuum machine, the amount of curing agent can be appropriately reduced for treatment. For example, the ratio of the original silica gel to the curing agent is 4%, and can now be changed to 1% to 2%. In this way, the gel of the previous mold will be slowed down, and the air in the mold will gradually discharge, reducing bubbles.

2. What happens when the silicone mold is cured and cured? This phenomenon is caused by the fact that 1. The ratio of silica gel to curing agent is not accurate and is not weighed as required; 2. The silica gel is not mixed well with the curing agent. Presenting this situation will result in the omission of the mold, and try to prevent it.

3. What should I do if the silicone exhibits a sticking mold? This situation is due to the fact that there is no reasonable treatment of the mold (product model) in the early stage, so the mold should be processed before the mold is opened, such as the appearance of the mold is rough or Do a very messy mold, be sure to polish it carefully and clean it. Then apply the release agent evenly. Commonly used release agents are petrolatum, detergent, liquid white wax and the like. In practice, different release agents can be applied according to the material of the mold. Second, the curing agent is mixed unevenly and poured into the mold. When it is taken off, it is not dry.

4. What should I do if the silicone mold product is deformed? This should be separated according to the size of the product. In principle, the size of the product is proportional to the hardness of the silica gel used. If it is a small product or a very sophisticated product, it can be opened with a soft silicone. The hardness is usually 10-20 degrees, which will release the mold and will not damage the texture of the precision product. If a large product is more than 50 cm, it must be opened with a silicone hardness of 40-50. This will not be deformed. If you are doing a very large and very sophisticated product, you can use a silicone with a hardness of about 30 degrees to open the mold (the method is to brush a layer of silica gel and coat a layer of fiberglass cloth and then brush a layer of silica gel....) The outer membrane is made of gypsum and glass reinforced plastic (ie, unsaturated resin + glass fiber cloth), so that the product to be protected is not deformed.

5. The general method and materials used for the manufacture of the outer mold are to surround the mold with rubber sheets or wooden boards. Gypsum can be used to fill the mold cabinets. Another method of resin coating is to apply a layer of resin and then apply a layer of fiberglass cloth, then brush and then post it. After two or three layers, the mold can be finished.

6. What is the difference between true and false silicone oil?

(1) Investigate with the eye: the fake silicone oil will be dirty, the smell is relatively large, and there is an odor;

(2) Test with fire: use a glass rod or iron rod to dip a small amount of silicone oil. The white mineral oil can be lit and black smoke, because white mineral oil is a petrochemical product. Pure silicone oil can not be incinerated, and it is odorless, clear and transparent, and non-toxic. The burning point of silicone oil is 320 degrees, and the burning point of white mineral oil is 100 degrees.

(3) Freezing point test method: 100 grams of pure silicone oil and white mineral oil are used together, put into the refrigerator together, and adjusted to -5-10 degrees together. After two hours of experiment, the fake silicone oil will be dirty or frozen. The real silicone oil is clear and transparent, even if it is at -50 degrees, it will not show freezing.

7. Slicing mold or sheet mold operation method: Apply vacuumed silica gel by brushing or pouring. Suppose you are using a stencil or a split mold. You can apply a layer of release agent or a separate preparation to the product or model you want to copy before painting. Then apply the silicone to the product. Note: Be sure to wait evenly. After waiting for 30 minutes, put a layer of gauze or glass fiber woven fabric on the outside to add strength, then apply a second layer of silica gel and other silica gel to dry, then make the outer mold. The outer mold can use plaster or Resin and other information.

8. Operation method of filling or pouring mold: filling or pouring mold is used for comparing lubrication or simple product. No mold line saves time and labor, it is the product or model you want to copy, using rubber sheet or glass. After the board is encircled, the vacuumed silica gel is poured directly onto the product. After the silica gel is dried and formed, the product is taken out and the mold is formed. (Note: the perfusion mold is generally made of a softer silica gel, so that the mold release is relatively simple. Will not damage the products inside the silicone mold.