Giving mold making its due

I have had the good fortune to work in several industries and I have discovered, in most cases, machining is the same from industry to industry. Cutting threads, milling keyways and boring holes is no different in an aerospace shop than in a shop that makes tractor parts.

Of course, there are some exceptions. In some shops the processes and machines might look the same, but machining processes are very different. A couple of examples that come to mind are tool and die shops that build progressive dies, gauge shops that make precise instruments and mold shops that create the tools for injection molding.

Specialty shops often use many of the same types of machines and tools, but the work they do is usually more demanding. Tolerances are tighter, materials are more difficult to machine, and the amount of machining needed can require many hours on a machine tool.

Challenging requirements associated with specialty machining often fuels creativity and innovation. Mold making is likely the best example of an industry whose challenges have produced some of the more well-known machining innovations in the last few decades.

Although mold makers produce tools for many types of manufacturing processes, mold making is most often associated with tools for injection molding of plastics. There are countless parts made by injection molding. Some of the more common are food containers, storage bins, toys and automotive trim.

Injection molding is the fastest and most cost-effective way to make commodity products making it a preferred process for manufacturers. Its popularity is evident in the number of products that have been transitioned from other manufacturing processes to injection molding. If you are old, like me, you have probably complained about all the plastic parts that used to be made of metal.

Mold making is most often associated with tools for injection molding of plastics, like these water bottles.”>

Whether you think plastic parts are good or bad, they are a huge part of manufacturing, and the use of plastic will continue to increase because the parts are economical. As demand for molded parts has increased and companies seek cost reductions, competition in the mold market has increased. Therefore, sending injection molds offshore has become a prevalent practice forcing domestic mold shops to seek efficiency improvements to remain competitive.

Mold machining is characterized by long machining cycles, deep pockets, complex contours and large volumes of chips. Unlike other machining operations, increased part density, set up reduction and similar activities are not effective ways to deliver efficiency gains. Making efficiency improvements in a mold shop requires higher removal rates. Simply stated, you must make chips faster.

Machine tool builders, cutting tool makers and software developers have responded to the demand for faster removal rates in the last decades by introducing new technologies to the market. Although there is not always a clear connection to these technologies, mold machining has greatly influenced general machining technology.