The growing importance of rapid prototyping in the industry of mold making

Molding is a procedure of manufacturing liquid or flexible raw material using a rigid frame called a mold or matrix. Mold is the hollowed block in which the liquid or the pliable raw material is dropped to shape the final outcome of the object. The liquid is left in the block to harden up at the end which takes the shape of the mold.

Rapid prototypes which are made from plastic part designs have become quite an important part in today’s mold making process for the mold builders. Generally rapid prototyping uses two major processes- stereo lithography (SLA) and selective laser sintering (SLS). A solid, three-dimensional part replica is produced from both the processes using CAD data.

Stereo lithography is a 3-D layer manufacturing process. It uses ultraviolet lasers to treat liquid photopolymer resins to manufacture solid, plastic, 3-D objects that simulate properties of polyethylene, polypropylene and polycarbonate materials. The machine used by the SLA technique of manufacturing has a software section which divides the 3D CAD model into manifold thin sheets. The SLA machine then paints one of the model sheets on the liquid plastic. This process is repeated again and again till all the sheets have been drawn and the model is complete. This process takes about 6-12 hours to be completed. It is very precise with the precision rate being approximately 0.005 inches.

Selective Laser Sintering is another prototyping process which can be used for mold making. In SLS method the liquid is replaced by heated powder. A laser is used which fuses the particles together, creating a 3D layer in the process. Nylon, polystyrene or alumide resins can be used as the heated powder. As in the SLS process here also the machine used has a software section which divides the 3D CAD model into thin layers. Then the laser melts the powder, layer by layer. As soon as one layer is complete new powder gets deposited on top of the solid layer and it is melted into another layer. This process is repeated again and again till the whole model is completed.

Both the SLA and SLS process are good. The choice of the process depends upon the wanted requirements for the final model. The SLS process is used if durability and good structural properties are the traits required in the final model. The SLA process is used to manufacture a good if finishing property is the trait required in the final model.

Rapid prototyping aids the mold makers in computing the correct design of a model. From the model the dimensions can be easily computed so that the parting lines in the mold can be accurately set up.

Mold makers are finding this method very effective as this both reduces the costs and also saves time. This is a growing industry all over the world and especially in China. In China rapid prototyping molds making techniques is being used by a number of companies as it is more effective.

This article is written by Doyle Clinton on behalf of Hecmold, this is having topics on Cheap molds, Rapid protopype mold, and many more.

Hecmold.com is a reputed name in unbeatable prototyping service in China, including Cnc machining, casing rapid prototypes and molds.