In addition to the added injection moulding machine factory complexity of the mold structure, adding any of these features will significantly increase the cost of the mold (and the cost of the product), not to mention the additional space each mold component takes up, compared to a simple mold design without side cores.If the mold had the same number of cavities, it may be necessary to make it much larger and thereby larger the machine to accommodate this extra mold area, despite the clamping forces needed being lower than with a mold without side cores or splits.If the mold has such features, such as side cores and splits, the cycle time will be longer and the productivity will be lower.

It may be possible to redesign round holes or openings of “odd shape” that arise from using split cavities or side cores without compromising the design of the product, the openings can be created in the side walls or even in the ribs with a design that blends the core and cavity together on a “shutoff”. Special inserts may need to be inserted in the cavity or in the core, which may require altering the sidewall’s shape or draft angle, or even a hole in the bottom.The end use of the product could be acceptable in many cases, and the mold could be simpler and therefore less expensive .

In many cases, a little redesign can result in significant savings on mold and product costs by simply giving more consideration to the product design while planning and designing a mold.A parting line placed in the obvious location may require a side core whereas the same product can often be molded with an up-and-down mold by slanting the P/L. This principle applies to any similar case, such as a simple louver.

Slanted” P/L molds cost more than ordinary P/L molds, but are far less expensive than side core molds.Often, a design specifies threads or undercuts, on the inside of the product . Is the specified shape of thread or undercut designed with molding in mind? Many such threads or undercuts could be molded without un- screwing, or the need for collapsible cores, by changing the shape of the undercut so that the product can be stripped off the core, i.e., the undercuts can easily slip out of the grooves that created them when pushed by ejectors or a stripper.