Silicon vacuum casting issues and solution

Vacuum casting is widely applied in prototyping process. At present, it is mainly used for prototype production, small batch production. Vacuum casting parts are used in following industries: Automotive, Communication and Security, Electronics, Engineering, Home Appliance, Medical, New Energy, Others. 

Common problems and solutions with vacuum casting:

1. Dimension deviation and product deformation

Causes and solutions: with the complex mold production process, especially the mold temperature control has a big impact on product quality. Other factors such as prototype master scaling and material shrinkage should also be controlled. Products over 1.5 m in length need to be made with reinforced molds.

2. Brittle and cracking of products

Causes and solutions: mainly due to the use of inferior materials and the defects of the duplication process, the solution is to ensure that the material procurement channels are guaranteed for good material, if there is no problem with the material, to improve the process, pay attention to the control of oven temperature and heating time, cooling time, cooling mode, etc.

3. Product features missing

Causes and solutions: in the production process of some relatively slender products, it is easy to lose features, the main reason is that the mold is not baked well and easy to deform. In addition, in the process of making the mold, the damage of the product prototype also directly leads to the loss of features of the product out of the duplicate mold. Solutions to improve the process must be in the prototype grinding, mold production, finished mold production of each link carefully checked.

4. Rough and uneven surface

Causes and solutions: the quality of the duplicating mold products has a great contribution to the prototype. It is necessary to improve the surface quality of the finished products. The first thing to do is to improve the production process and surface effect of the prototype. In addition, the use of inferior silica gel will also lead to rough and uneven surface of the mold. The solution is to use good quality silica gel mold production, select the most appropriate process to make the prototype, to ensure the hardness of the material, the surface and the compatibility between the materials.

5. Bubble and hollow

Causes and solutions: the bubbles in the complex mold products are related to the reaction of silica gel mold material and curing agent. The time of vacuum pumping should be controlled well. If the time is too long or too short, bubbles will be easily generated. In addition, it is related to the product structure and the position of the feed port. Bubbles on the surface of the product will greatly affect the appearance of the product and the durability of the material, so it must be made in strict accordance with the technological process to effectively avoid.

6. Color fade and orange peel surface

Causes and solutions: color fade is with product surface roughness, the choice of primer pain and topcoat paint and involve many reasons. The main solution is to choose compatible materials, such as a two-component special paint primer plus car paint; good paint can not only improve product surface effect, but also increase the resistance to aging, corrosion resistant function.

7. Parts could not be assembled

Cause and solution: in some cases, the drawings are drafted according to the injection molding process and the difference between the duplicate molding process and the injection molding process is not considered. The vacuum casting process is vacuum adsorption forming; the precision of the product can be controlled within ±0.1mm. Process engineers need to adjust the prototype of the complex mold for the assembly products with higher precision requirements or the required hand feeling tightness, and the assistance of post-processing can meet the requirements of the assembly.

        At Accu, we have a dedicated vacuum casting team for mold design and production. If you have any prototype or production needs, please kindly contact with our product manager Flemming at This email address is being protected from spambots. You need JavaScript enabled to view it.. Thank you!