Vacuum Casting - Urethane castingLeshine is fully capable of handling your vacuum casting and
silicone molding needs. With years of expertise in the field, we
can fabricate your parts to the highest standard and with fast
turnarounds. Vacuum casting is a great way to make rigid or flexible parts, and
is ideal for prototypes, engineering testing, concept proofing and
display demos. These parts can be made from hundreds of casting
polymers. Contact us today for more information Advantages of Vacuum Casting1. Fast turnaroundLeshine can provide up to 20 parts in 15 days or less, depending on
part specification and volume. 2. AffordabilitySilicone molds are less expensive than the tooling used for
injection molding, resulting in low prices. 3. Capable of producing large partsDepending on the type of equipment used, vacuum casting can to
create very large parts. 4. Superior surface finish to injection moldingThe vacuum process removes air bubbles and allows the material to
capture fine details. 5. Color optionsColoring pigments can be added to the resin for a variety of color
options. 6. RepeatabilitySilicone molds can be used around 20 times before they need
replacing. What is Vacuum Casting?Vacuum casting is a manufacturing technology that uses a vacuum to
draw liquid material into a mold. It differs significantly from
injection molding, which pushes liquid material into a mold using a
screw. The process of vacuum casting offers significant advantages,
and is particularly useful for parts that have undercuts or fine
details. The process starts with a master model, which Leshine
creates using one of its CNC machining centers — though 3D printing
can also be used. This master model is then immersed in liquid
silicone, which is cured and becomes the mold. Once it has been cut
and the master model removed, the silicone mold can be put to use.
This stage involves pouring casting resin into the mold, as the
vacuum removes bubbles and air pockets to ensure a smooth finish.
The resin part is then cured and removed from the silicone mold,
which can be reused around 20 times. Each resin part is an exact
copy of the original master model. Vacuum Casting Process| Step 1:Master building | Masters are 3D solids of your CAD designs. They are usually made by
CNC machining or with 3D Printing. Making Master in 40°
temperature. After finish and inspect the masters, we will move to
silicone mold making. | | Step 2: Mold making | Casting molds are made from liquid silicone. Half-Fill the casting
box with liquid silicone, Heat the casting box until silicone is
fully cured and then allowed to cure in an oven for 16 hours. Fill
with extra silicone liquid which is also heated & cured. Once
dried, the mold is cut open and the master removed. | | Step 3: Make the parts | Poured the casting resins into the empty cavity to create a highly
accurate copy of the original. It’s even possible to overmold with
two or more materials. Silicone molds are typically good for 20 or
so copies of the master pattern. |
Vacuum Casting Technical Specifications| Typical lead time | Up to 20 parts in 15 days or less, depends on the part
specification and volumes. | | Accurate | ± 0.3% (with lower limit on ± 0.3 mm on dimensions smaller than 100
mm) | | Minimum wall thickness | To ensure that the mold is filled properly, a wall thickness of at
least 0.75 mm is necessary. For best results, we recommend a wall
thickness of at least 1.5 mm | | Maximum part dimensions | The size of the mold is limited by the dimensions of the vacuum
chamber (1900 x 900 x 750 mm) and by the volume of the product
(maximum volume: 10 liters) | | Typical quantities | Up to 25 copies per mold (depending on the mold’s complexity and
the casting materials) | | Color & Finishing | Pigment is added to the liquid polyurethane prior to casting,
custom painting and texture. |
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