advanced casting process

2. A KARTHIKEYAN
07095949495

3. What is Vacuum Casting?
• Vacuum mold casting, also known in manufacturing industry as the V process,
employs a sand mold that contains no moisture or binders. The internal cavity
of the mold holds the shape of the casting due to forces exerted by the pressure
of a vacuum. Vacuum molding is a casting process that was developed in Japan
around 1970.
• Vacuum Casting is a fast and cost-effective prototyping method that is typically
used to produce small numbers (usually up to 20) of highly accurate
polyurethane prototype parts.
• It is a slightly slower process than SLA alone because of the additional steps
involved in the process, some of which are manually intensive. The time to
manufacture depends on the desired characteristics of the part, with size being a
key factor as this affects the curing time of the material.
• Small numbers of parts are made from a single master mould, which is made
using an SLA master model. The mould is made from silicone rubber, and the
casting made by pouring resin into the mould in a vacuum chamber.

4. • The result is a bubble free casting, ideal for highly accurate,
functional plastic prototype parts in very fine detail which
replicate patterns, dimensions, profiles and textures.
• Vacuum Casting can also produce parts with varying degrees
of flexibility or rigidity, in a wide range of colours and
materials – as well clear parts.

5. • A special pattern is used for the vacuum mold casting process. It is either a
match-plate or a cope and drag pattern with tiny holes to enable a vacuum
suction. A thin plastic sheet is placed over the casting pattern and the
vacuum pressure is turned on, causing the sheet to adhere to the surface of
the pattern.
• A special flask is used for this manufacturing process. The flask has holes
to utilize vacuum pressure. This flask is placed over the casting pattern and
filled with sand.
The Process :

12. Properties And Considerations Of Manufacturing By
Vacuum Mold Casting
• In vacuum mold casting manufacture there is no need for special molding sands or
binders.
• Sand recovery and reconditioning, a common problem in metal casting industry, is
very easy due to the lack of binders and other agents in the sand.
• When manufacturing parts by vacuum mold casting the sand mold contains no water,
so moisture related metal casting defects are eliminated.
• The size of risers can be significantly reduced for this metal casting process, making
it more efficient in the use of material.
• Casting manufacture by vacuum molding is a relatively slow process.
• Vacuum mold casting is not well suited to automation.

13. Vacuum chamber is equipped in driver which manage all
processes: pumping out air from chamber, mixing resin
components, and pouring ready resin to mould. Characteristic
technical data about our device for vacuum casting are:
• Working area which determine maximum dimensions of
produced moulds 450 x 425 x 530mm;
• Time for silicone rubber mould preparation: 12h;
• Time for single resin casting: 40-50min.