What is the difference between casting and molding?
The difference between Casting and molding is that in one material, mold, and output product has a lot differences.
The difference between Casting and molding is that in one material, mold, and output product has a lot differences.
Generally the term casting is used, when the material used is a metal & v belt for non-metals such as plastics (in UK English). From what i have seen in American books, the term mould is used for a die - gravity die/permanent mould & pressure die casting/ die casting
Both the process is very similar in which molten material is poured in to the close mold / die which will take the shape of the cavity of close mold and then it cured and removed from the mold.
The basic different is the method of pouring the material in to the mold. In garden tool it will be poured the material pressure and in most of the casting process, it does not require any external force to pour the material as the molten material has very less viscosity and is capable to flow with its gravitational force only.
In packing machine process the output is the final finished part but in most of the casting process, the output is unfinished part that required the final finishing(machining).
Casting - generally for metal and input metal enters by gravity in to the cavity.
Moulding - both metal and non metal,cavity is used repeatedly. the input can be by pressure or gravity.
Sometimes they can be mixed up . Say in Battery making. the Grid is made in "grid mould" by pouring molten alloy, but the pressure washer on which the Mould is mounted is called "Grid Casting Machine".
Casting uses a "one time" use mold while molding you can repeat the process with the same mold.
Gravity die cast and pressure die cast, uses same mold again and again.
As cleared earlier, normally, metals process is called casting and plastic process is called display stand.
And that is why I cast my model parts out of resin cast plastic in a reusable mold .
Another die casting processes is "slush-casting", where metal is poured into a mold, allowed to cool slightly, hardening on the outside of the object only, forming a shell. Then the molds are inverted to pour out the "slush" or not yet-hardened inner material. This is used to create hollow objects where the inside finish is no concern and where it is desirable to reduce weight or save material.
One process similar to slush-casting is called rotational molding. Like slush-casting, it is used to produce hollow objects, usually from thermoplastics. The raw material resin is usually in powdered form or in very small beads. These molds are permanent and reusable "Clamshells", which form the exterior. A measured amount of resin is placed inside the pre-heated molds. The molds are mounted so that they turn slowly on two axes, distrubuting the resin evenly over all the surfaces of the mold while it bakes in an oven. The heated metal melts the resin that touches it forming a skin inside the mold. As heat is transferred through the skin to the remaining resin, more of it sticks to the skin, and thickens it. Eventually, when this skin is thick enough, all or most of the resin is consumed and the mold is allowed to cool. Finding out how much resin to use is often a trial and error process, as some sections build up quicker and thicker than others.
For more information on other casting and molding processes get a good Manufacturing Engineering textbook and that will cover almost all the basic processes.