The Molding Process:
No Bake is a casting process that uses chemical binders to bond the molding sand. The sand is then transported to the mold fill station in preparation for filling of the mold. A mixer is then used to blend sand with the chemical binder and the catalyst. When the sand exits the mixer, the binder begins the hardening process.
After the compaction process, a rollover process is used to remove the mold from the pattern box. The mould is then readied for handling the molten metal. After a shakeout process, the molded sand is taken away from the casting. Then various procedures follow including the finishing and the sand can be reclaimed by thermal means.
In the No-Bake resin sand casting process, sand molds are created using a wood, metal, or plastic pattern. Sand is mixed with a plastic binder in a high-speed mixer. This sand is deposited into box containing the pattern and all essential gating, risers and chills for pouring.
The sand mixture sets up hard in a few minutes and the mold is removed from the pattern. Cores for forming internal passages in the castings are made using the same process. Cores are carefully placed into the molds. The molds are then closed and are ready for pouring.
The chemical nature of the binders makes this a highly specialized process that has to been handled with considerable expertise and knowledge.
The No-Bake casting technique creates molds with excellent dimensional stability. The casting surface finish is also improved over other sand casting processes. No-Bake is one of the most efficient and advanced sand casting techniques currently available.
No-Bake Sand Molding requires a chemical binder to hold the sand together. This type of system allows for the production of more complicated castings. Castings that are selected for this process usually are extremely large castings, require deep pockets, or limited draft situations.
Another important feature to No-Bake Sand Molding is that there are no products of combustion incorporated in the material. Consequently, castings that require a high level of x-ray quality can be produced on a regular basis.
So, the chemical binders are used to create high strength moulds. When the temperature is brought to normal levels, the molds turn rigid.
1. It is adaptable to any quality.
2. It creates high strength moulds and improves dimensional repeatability.
3. Requires low skill and labor requirements
4. Provides better dimensional control.