Shell mould casting line, which is sometimes known as shell mould casting, is a metal casting process similar to sand casting, in
that molten metal is poured into an expendable mold. However, in shell mold casting, the mold
is a thin-walled shell created from applying a sand-resin mixture around a pattern. The pattern,
a metal piece in the shape of the desired part, is reused to form multiple shell molds. A reusable
pattern allows for higher production rates, while the disposable molds enable complex geometries
to be cast. Shell mold casting requires the use of a metal pattern, oven, sand-resin mixture,
dump box, and molten metal.
Shell mold casting allows the use of both ferrous and non-ferrous metals, most
commonly using cast iron, carbon steel, alloy steel, stainless steel, aluminum alloys, and copper
alloys. Typical parts are small-to-medium in size and require high accuracy, such as gear housings,
cylinder heads, connecting rods, and lever arms.
The shell mold casting process consists of the following steps:
1. Pattern creation - A two-piece metal pattern is created in the shape of the desired
part, typically from iron or steel. Other materials are sometimes used, such as aluminum for
low volume production or graphite for casting reactive materials.
2. Mold creation - First, each pattern half
is heated to 175-370°C (350-700°F) and coated
with a lubricant to facilitate removal. Next,
the heated pattern is clamped to a dump box,
which contains a mixture of sand and a resin
binder. The dump box is inverted, allowing this
sand-resin mixture to coat the pattern. The
heated pattern partially cures the mixture,
which now forms a shell around the pattern. Each
pattern half and surrounding shell is cured to
completion in an oven and then the shell is
ejected from the pattern.
3. Mold assembly - The two shell halves are joined together and securely clamped to form
the complete shell mold. If any cores are required, they are inserted prior to closing the mold.
The shell mold is then placed into a flask and
supported by a backing material.
4. Pouring - The mold is securely clamped together while the molten metal is poured
from a ladle into the
gating system and fills the mold cavity.
5. Cooling - After the mold has been filled, the molten metal is allowed to cool and solidify
into the shape of the final casting.
6. Casting removal - After the molten metal has cooled, the mold can be broken and the casting
removed. Trimming and cleaning processes are required to remove any excess metal from the feed
system and any sand from the mold.
Shell mould casting allows the use of both ferrous and non-ferrous metals, most commonly using cast iron, carbon steel, alloy steel, stainless steel, aluminum alloys, and copper alloys. Typical parts are small-to-medium in size and require high accuracy, such as gear housings, cylinder heads, connecting rods, lever arms, small size boats, truck hoods, camshaft, valve body, etc
Item | Z955(SG)-15 | Z956(SG)-25 | Z957(SG)-40 | Z958(SG)-45 | Z959(SG)-50 | Z9510(SG)-60 |
Max size of core box(mm) | 500*500*300 | 600*600*400 | 700*700*400 | 800*800*450 | 900*900*500 | 1000*1000*600 |
Pattern opening/closing distance(mm) | 250~650 | 250~800 | 300~800 | 300~900 | 300~900 | 400~1000 |
Max sand shooting capacity(kg) | 15 | 25 | 40 | 45 | 50 | 60 |
Cycle time of single working station(s) | 15 | 20 | 20 | 30 | 30 | 35 |
Drive mode | Pneumatic/Hydraulic | Pneumatic/Hydraulic | Hydraulic | Hydraulic | Hydraulic | Hydraulic |
Way of taking core out | Built-in/shift out | Built-in/shift out | Built-in/shift out | Shift out | Shift out | Shift out |
1.Low equipment investment, small occupied area, convenient production and high productivity.
2. High dimensional accuracy and good surface finish.
3. Suitable for thin and complex castings.
4. No further machining required.