How to make plastic injection mold

The process of making a plastic injection mould consist of determining what should be the size of
the mold, designing the mold, ordering required materials for the design, creating a rough shape, heating the mold, precision machining, wire cutting, polishing and fitting and trial of the mold.

Step 1: Determining the size of the plastic injection mold.

This process is not hard and does not require a lot of time. The end product, the plastic shape, determines the size of the mold.

Step2: Designing the mold.

Computer CAD design is used to draw the design. First set a 2 dimension layout and make sure you have all the mold
design features marked such as the size of the mold, parting line, the layout of the cavities are all set. Note the information that will be needed such as the mechanical design and the accessories that will be used.

After the two dimension layout made is satisfying and all information is noted make a
detailed 3D design. This will require programming skills to create. It may take some time to complete the designing with regards to the complexity of the mold.After the first 3D design is made it is necessary to assess any need for adjustments and the flow of the mold.

Step 3: Ordering the required molding material

After your design drawing is completed its time to order the required material. This may include desire steel, cutting tools and plastic part samples.

Step 4: Creating a rough shape of the plastic molds

Sizing of the steel then milling and drilling comprises this step. Make the desired steel shape and drill the holes needed as per the design in a rough work machine. Leave polishing and smoothing for later.

Step 5: Heating the mold

Heating is done as a form of treatment after creating the rough shape to harden and balance the created steel shape. Not every type of steel may need heating, an example, the P20.

Step 6: Precision machining.

Precision machining works slower due to the hardened steel properties but will get the design dimension created as per the design drawing.

Step 7: Wire cutting and EDM

Wire cutting is a process where special holes are made in to the design. These holes include pin holes for the ejector, for the lifters and the inserters. EDM helps work on narrow spaces which cannot be machined easily or where the space is too small for the cutting tool to get in.

Step 8: Polishing and fitting
polishing and fitting the created mold in to the mold maker machine follows.
The mold maker machine will collect all parts put into it and will follow the
design drawing to make the finished plastic mold. When the machine work is done further
polishing and engraving follows to complete the design.

Step 9: Trying the mold.

After the mold is created it will be good to try if it will work for the desired plastic shapes. The mode is installed in the plastic injection molding machine and injection parameters are set to work on the plastic samples acquired. If the mold is good enough for the job, well and good, the mold creation process is complete. You can now proceed to create the desired plastic products or sell the design to another company.