Concept of vacuum casting
Silicone re-molding, also known as vacuum casting, refers to the use of the original prototype, the production of silicone molds in a vacuum state, and the use of PU, silicone, nylon ABS, and other materials in a vacuum state for casting, so as to clone the same replica as the original prototype restoration rate of 99.8%. Silicone replica mold production cost is low, free of mold, short production cycle, the service life of about 15-25 times, suitable for full small batch customization.
Silicone replica mold process
Silicone molding materials: ABS, PC, PP, PMMA, PVC, rubber, high temperature resistant materials and other materials.
1、Make the prototype: According to the 3D drawing supplied by the customer, the prototype will be made by CNC machining, SLA laser rapid prototyping or 3D printing.
2、Pouring silicone mold: After making the prototype, make the mold frame, fix the prototype, pour the silicone, after 8 hours of drying, open the mold and take out the prototype, the silicone mold manufacturing is finished.
3, injection: the liquid plastic material into the silicone mold, in the 60 ° - 70 ° constant temperature oven for 30-60 minutes after curing, can be removed from the mold, if necessary, in the 70 ° - 80 ° constant temperature oven for 2-3 hours of secondary curing. Generally speaking, the life span of silicone molds is 15-20 times under normal circumstances.
What are the applications of silicone re-molding?
1, plastic hand plate: its raw material is plastic, mainly some plastic products hand plate, such as televisions, monitors, telephones and so on. Like the most common photosensitive resin in 3D prototyping belongs to the plastic hand plate category.
2、Silicone lamination plate: its raw material is silicone, mainly to show the shape of the product design plate, such as cars, cell phones, toys, handicrafts, daily necessities and so on.
Advantages and characteristics of silicone compound mold
1, silicone compound mold has the following advantages:
1) Low production cost. The processing cost is also much lower than CNC processing and 3D printing;
2) Short production cycle. Save the time to open the mold, greatly provide production efficiency;
3) free of mold opening. Save the time to open the mold, for customers to develop new products to win valuable time to seize the market opportunity;
4) High degree of reduction, processing failure rate is small;
(5) Suitable for small batch production, short customization time, low cost;
6) Exquisite workmanship, no burrs.
2, vacuum remodeling advantages compared to other hand plate process has its advantages, with the following characteristics: free mold, low processing costs, short production cycle, high degree of simulation, suitable for small batch production and other characteristics. Favored by the high-tech industry, silicone re-molding can accelerate the progress of research and development, to avoid unnecessary waste of funds and time costs during the research and development.
3, the characteristics of small batch silicone re-molded hand plate
(1) silicone mold does not deform, does not shrink; high temperature resistance, mold molding can be used repeatedly; for product imitation supply convenience;
(2) Silicone molds are inexpensive, short manufacturing cycle, before opening the mold can prevent unnecessary loss.
What are the characteristics of a failed vacuum casting finished?
1. Rough or Uneven Surfaces:
A failed finish can result in surfaces that are rough, uneven, or textured. This could be due to improper mold preparation, inadequate mold release agents, or issues with the casting material itself.
2. Visible Defects:
Defects such as pits, dimples, dents, scratches, or irregularities on the surface can indicate a failed finish. These defects might be caused by improper mold handling, insufficient mold filling, or inadequate venting.
3. Bubbles or Porosity:
Small air bubbles or pores on the surface of the cast part are indicative of a failed finish. These defects can occur due to inadequate degassing of the casting material or improper vacuum during the casting process.
4. Inconsistent Texture:
If the intended texture of the finished part is not achieved, it can be considered a failed finish. This might result from issues with mold texture replication or problems during material solidification.
5. Flash and Excess Material:
Flash refers to excess material that protrudes from the parting line of the mold. It can occur when the mold halves don't align properly or when the casting material leaks into unwanted areas.
6. Color Variation:
If the cast part is meant to have a specific color or appearance, any variations from the intended color can be considered a failed finish. This could be due to improper mixing of pigments or inconsistencies in material properties.
7. Delamination or Layer Separation:
For composite materials, delamination or separation between layers can lead to a failed finish. This might be caused by poor adhesion between layers or inadequate curing.
8. Warping or Distortion:
If the finished part deviates from the intended shape due to warping or distortion, it indicates a failed finish. This could result from improper cooling or solidification during the casting process.
9. Incomplete Details:
If the cast part does not replicate the intended details and features from the mold, it can be considered a failed finish. This might occur due to issues with mold design, material flow, or mold release.
10. Inadequate Gloss or Shine:
If the cast part is meant to have a glossy or shiny finish but lacks the desired luster, it can be considered a failed finish. This might result from improper mold polishing or issues with the casting material's properties.
11. Cracks or Fractures:
If the finished part exhibits cracks or fractures on the surface, it signifies a failed finish. This could be due to improper material properties, improper cooling, or excessive stresses during solidification.
12. Chemical or Staining Reactions:
If the casting material reacts with the mold or other components during the process, it can lead to discoloration, staining, or chemical reactions on the surface.
What are the main causes of the above problems?
1. Rough or Uneven Surfaces:
Inadequate mold surface preparation or polishing.
Poor mold alignment and closure during the casting process.
Improper material mixing or poor dispersion of additives.
2. Visible Defects:
Mold misalignment causing leakage and flash.
Insufficient venting leading to air entrapment.
Mold damage or wear causing irregularities.
3. Bubbles or Porosity:
Inadequate degassing of casting material before pouring.
Insufficient vacuum pressure during the casting process.
Improper material-to-mold temperature balance.
4. Inconsistent Texture:
Insufficient mold texture replication or mismatch.
Inadequate mold release agents affecting texture transfer.
Incorrect material pouring or curing methods.
5. Flash and Excess Material:
Poor mold closure and alignment causing material leakage.
Incorrect gating and venting design leading to material overflow.
6. Color Variation:
Inaccurate pigment mixing or dispersion.
Variability in material properties affecting coloration.
Material contamination with other substances.
7. Delamination or Layer Separation:
Poor adhesion between layers in composite materials.
Incomplete curing or improper curing conditions.
8. Warping or Distortion:
Rapid cooling causing uneven contraction and warping.
Incorrect cooling channel design and placement.
Improper material selection leading to excessive thermal stresses.
9. Incomplete Details:
Poor mold design not accommodating intricate features.
Inadequate material flow into complex mold areas.
Mold release agents hindering detailed replication.
10. Inadequate Gloss or Shine:
Insufficient mold polishing or maintenance.
Incorrect curing or processing conditions affecting surface properties.
Incorrect surface treatments or finishing techniques.
11. Cracks or Fractures:
Rapid cooling leading to thermal stresses and cracking.
Inadequate material properties for the intended use.
Incorrect gating and venting causing uneven material distribution.
12. Chemical or Staining Reactions:
Incompatibility between casting material and mold surface.
Chemical reactions between casting material and additives.
Contaminated molds or tools reacting with casting material.
How to avoid them？
1. Rough or Uneven Surfaces:
Properly polish and prepare mold surfaces before casting.
Ensure accurate mold alignment and closure.
Use suitable mold release agents to facilitate part removal.
2. Visible Defects:
Ensure precise mold alignment and closure.
Design effective gating and venting systems.
Regularly inspect molds for damage or wear.
3. Bubbles or Porosity:
Thoroughly degas casting materials before pouring.
Maintain consistent and sufficient vacuum pressure.
Follow recommended material pouring and curing techniques.
4. Inconsistent Texture:
Carefully replicate mold textures and surface treatments.
Apply appropriate mold release agents for texture transfer.
Adhere to recommended curing and processing conditions.
5. Flash and Excess Material:
Ensure proper mold closure and alignment.
Design gating and venting systems to prevent overflow.
Monitor material pouring to prevent leakage.
6. Color Variation:
Accurately measure and mix pigments or additives.
Use consistent casting materials with reliable properties.
Prevent contamination of materials during preparation.
7. Delamination or Layer Separation:
Ensure proper adhesion and curing of composite layers.
Follow recommended curing schedules and conditions.
Implement proper material mixing techniques.
8. Warping or Distortion:
Implement controlled cooling to prevent rapid temperature changes.
Optimize cooling channel design for even cooling rates.
Select materials with suitable thermal properties.
9. Incomplete Details:
Design molds with appropriate features and allowances.
Optimize gating and venting for complex mold areas.
Use proper mold release agents for detailed replication.
10. Inadequate Gloss or Shine:
Thoroughly polish mold surfaces to desired finish.
Follow recommended curing and processing conditions.
Apply appropriate post-processing techniques for desired gloss.
11. Cracks or Fractures:
Control cooling rates to minimize thermal stresses.
Select materials with suitable mechanical properties.
Design gating and venting for uniform material distribution.
12. Chemical or Staining Reactions:
Choose compatible materials for molds and casting.
Use clean and well-maintained molds and tools.
Minimize exposure to contaminants during the process.
