LFC or EPC sand molding line,lost foam casting --casting equipments--Qingdao Shengmei Machinery Co., Ltd.

Qingdao Shengmei Machinery Co., Ltd.

青岛盛美机械有限公司

casting equipments

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LFC or EPC sand molding line,lost foam casting Updated At: 2025-07-31

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Introduction:
The Lost Foam casting process originated in 1958 when H.F. Shroyer was granted a patent for a cavity-less casting method, using a polystyrene foam pattern embedded in traditional green sand. The polystyrene foam pattern left in the sand is decomposed by the poured molten metal. The metal replaces the foam pattern, exactly duplicating all of the features of the original pattern. Like other investment casting methods, this requires that a pattern be produced for every casting poured because it is evaporated (“lost”) in the process.

The basic steps to the process include:

A foam pattern and gating system are made using a foam molding press
The foam pattern and the gating system are glued together to form a cluster of patterns
The cluster is coated with a permeable refractory coating and dried under controlled conditions
The dried, coated cluster is invested in a foundry flask with loose, unbonded sand that is vibrated to provide tight compaction
The molten metal is poured on to the top of the gating system which directs the metal throughout the cluster and replaces the foam gating and patterns
The remaining operations such as, shakeout, cut-off, grinding, heat treat, etc. are straightforward and similar to other casting processes.

Lost foam process sand casting has the advantges as belowed:

This casting process is advantageous for very complex castings that would regularly require cores.
It is also dimensionally accurate, maintains an excellent surface finish, requires no draft, and has no parting lines so no flash is formed.
As compared to investment casting, it is cheaper because it is a simpler process and the foam is cheaper than the wax.
Risers are not usually required due to the nature of the process; because the molten metal vaporizes the foam the first metal into the mold cools more quickly than the rest, which results in natural directional solidification.
Foam is easy to manipulate, carve and glue, due to its unique properties.
The flexibility of LFC often allows for consolidating the parts into one integral component; other forming processes would require the production of one or more parts to be assembled.

Process & Operating principle

1. Mold foam pattern sections.
2. Age pattern to allow dimensional shrinkage.
3. Assemble pattern if it is a multiple piece pattern.
4. Build cluster (multiple patterns per cluster).
5. Coat cluster.
6. Dry coating.
7. Compact cluster in flask.
8. Pour metal.
9. Extract cluster from flask.