Pour Molding

Pour Molding is a technique used when manufacturers or individuals wish to create multiple items.  It is performed by pouring liquid into a mold or pattern for the purpose of producing either another mold or a finished piece.  The mold is a hollowed out block that can be filled with whatever material you would like, as long as it is a liquid.  The liquid inside the mold then hardens (the slow part of pour molding) and as it does, it takes on the shape of the hollow part of the mold.  A substance known as a release agent is used to release the piece from the mold. The name for a manufacturer of molds for Pour Molding is Mold maker. Pour molding is also called Plastic Molding, Urethane Casting, or Plastic Potting. 

What Types of Parts are Good Candidates for Pour Molding?

The most common use for Pour Molding is producing the silicon molds used to produce prototype parts as well as urethane castings.   Additionally, this method is used to produce plastic parts that are to be used in a low-volume runs.  Further uses of Pour Molding extend to glass, metal and ceramic raw materials. 

Designing Parts for Pour Molding

The first step in designing a Pour Mold is selecting the right material for your mold.  A material called RTV (Room Temperature Vulcanizing) silicone rubber is probably the most widely available and easy to use material. This material comes as a liquid, but when you add the right ingredient, it turns into a solid.  When making the mold you must have master part.  It should be almost exactly like the pieces you wish to end up with.  If you place the master piece on something hard but disposable (such as a cardboard box) you can create the mold from the master piece within the box. Once the mold is prepared, you can pour the material you wish you finished piece to be made from into your mold.  Casting resins are used to mold plastic parts.  The casting resin must be mixed thoroughly and have no air bubbles in order for your mold to work properly.  Make sure to adhere to drying times before you remove your cast from the mold.

Sourcing Pour Molding

Set-up costs for Pour Molding are relatively low (as compared to other methods of producing multiple items or molds). Low set-up cost also means that no special equipment is required in order to Pour Mold