Even the simplest injection molded part can be a risky undertaking for those without the experience.   Tooling can be expensive and a bad tool design can lead to a huge unforeseen failure months down the road.   The most important thing you can do is to mitigate the risks at the beginning of the project in order to ensure the best possible outcome.  We mitigate the risks by identifying as many of the possible pitfalls that we can.   PPT has developed a framework for identifying risks during the quote stage so that we can ensure the over all success of the project.   This framework evaluates several areas of risk that are common to new injection molding projects.   Risk Assessment occurs during nearly all phases of the project, but what i will talk about today is risk assessment during the pre-production or quote phase.

The first risk category we look at is part design.   We evaluate the drawings at a very detailed level and try to identify “difficult to mold” geometry or part geometry that may cause molding issues in the future.   Improperly designed parts can lead to voids, sink, dimensional issues and extra cost for the customer due to excessive cycle time.  Lets say we run into a part that has a very thin wall that may not fill properly because the plastic cannot flow.  We may recommend that the customer thicken that section or conduct a mold flow analysis to ensure the part will fill.  Mold flow is an excellent resource to evaluate injection molded part design.

Material selection is important and can add to risk if you do not have a good grasp on material science. if you choose the wrong material for a particular application it may fail in the field.  If you have a low volume part that uses 500 lbs of material a year but you select a special material that  has a minimum order requirement of 6600 lbs your costs will increase.  We try to evaluate if the material selected is the right material for the job and is capable of meeting the dimensional requirements on the drawing.   We also look at any risk associated with the supply of the material.   These are all important risks that must be evaluated prior to production.  Our material suppliers are great resources and offer design guides for most of their materials.   We will review the design guide and spec sheet for important information such as tool design or processing parameters.   Some times, we may get our material suppliers involved in the material selection process.

We look at this section to mitigate risk associated with labor.  Ideally when injection molding a part, we try to design the tooling so that the part will de-gate automatically which reduces the amount of labor required for the job and lowers cost.   Sometimes, reducing the labor is not an option, for instance, when an operator has to hand load an insert for over molding.  When it comes to labor risk, we have to look at the requirements of the job and ensure that we have the type of labor that is qualified to run the job. Does this job require skilled labor with specific technical expertise?   Can the job be performed with unskilled labor?  What happens when an operator fails to follow procedure?  Take the hand-loaded insert example that I provided, what happens when the operator loads the insert wrong.  Does it crash a multi-thousand dollar tool?  If that is the case, we mitigate the risk by Pokeyoke’ing the tool to ensure the operator cannot fail.

In many cases we don’t know the end use of the product, but this is information that we always try to gather.  We need to know if this is a critical safety item.  PPT will try to look at how the part is going to function in the environment it is to be used in.   Our customers know their products far better than we do but we will look for any red flags or risks that we can find.   For instance, if we know this is an outdoor application but the customer has chosen a material that does not have any UV protection.   PPT would identify that as a material risk and notify the customer.

Sometimes parts have a specific set of  requirements that we have to plan for.  Some medical parts may have more stringent FDA requirements than others and PPT will need to plan accordingly to ensure that we can meet the customers and the regulating body’s expectations.   This category can encompass, regulatory or statutory concerns.