A plasstic mold maker and mold assembly job are the molds core works when make plastic molds.The mold base has been constructed by a moldbase supplier. All the injection mold components are on hand, and the only thing remaining is the mold assembly.
Plastic mold maker is required to manufacture the highly detailed core and cavity components, fit all the pieces together precisely, and do the final assembly of the mold. This is often where a multitude of discrepancies are revealed.
The plastic mold maker must then have the judgement to determine what needs grooming, what can be left alone, which details are important, which ones are irrelevant. and so on. This skill can only be gained by experience.
Very often, the mold assembly is done in haste because the project is overdue. This is a formula for mistakes. Another common problem is leaving the job half-finished for somebody else to complete. This is also asking for trouble.
Suppose that the first shift assembles the mold 60% and leaves the other 40% for the second shift. Even with the best of communication skills (which is very rarely the case), a great deal is left unspoken and taken for granted.
Larger molds have many, many components and all of them have a specific purpose and position. If one is out of location it could be disastrous for the job.
This is why it is much better to have one or two people responsible for the assembly: from beginning to end. The chance for error is just too great to pass the job on from one shift to the next. Obviously, there are exceptions.
Project managers have, at times, tried to write an assembly procedure manual for various jobs. This is an exercise in futility. It is nearly impossible to explain how to assemble an injection mold, and even more impossible to follow the directions!
One solution is to have the lead plastic mold maker for the job be responsible for the assembly. If there is no one lead man, then one must be assigned. Once somebody has become intimately familiar with the job, he is more or less married to it. He may be able to pass on the information to another mold maker, but it is the experience that qualifies him for the task.