When Matrix Tooling, Inc. first acquired ISO 9001 certification in February, 1999, our primary motivation was to increase our sales potential with a larger number of OEM’s. We were good at designing and building precision plastic injection molds and molding custom parts. The quality of our work and our responsiveness to customers had earned us a good reputation over the previous two decades. Our existing customers were pleased with our performance and were not requiring us to be ISO 9001 certified. But we decided to pursue it anyway on our own terms – and on our own timeline – to stay ahead of our competition.

We quickly realized the internal benefits of modeling our quality management system (“QMS”) on the ISO 9001 standard. The consistency that ISO brought to all areas of the company yielded obvious improvements. We became more consistent in how our jobs were quoted, documented, designed, processed and inspected; this led to a greater degree of control and confidence throughout the company. Consistency in our purchasing methods and receiving inspections led to the virtual disappearance of vendor returns. Formal management review meetings took place at regular intervals, bearing targeted plans of continual improvement.

In short, ISO 9001 made us better while giving our sales force increased credibility with potential customers. Today, ISO 9001 certification is almost expected; a prerequisite for doing business in almost any industry.

Over the years, Matrix has increased our focus on medical device applications where our detailed micro-tooling, close-tolerance molding and advanced inspection capabilities provide a natural fit. We added a class 100,000 clean room and cross-sectional scanning (“CSS”) technology.

But we also discovered that the quality standard specific to the medical device industry is ISO 13485, not ISO 9001. Though its structure is based on 9001, 13485 contains additional requirements for risk management, regulatory compliance, traceability, contamination control, and device history documentation.

Our medical customers come to Matrix with device design concepts and requirements for how their devices must function. Our design engineers are often involved in the development stage from a production perspective and make recommendations for resolving part geometry, material selection and other manufacturability issues. While we are technically a second-tier supplier, not the “specifications developer,” we are certainly invested and involved in the success of these products and consider ourselves a critical link in the supply chain. If a customer gets audited by the FDA, we want to be well equipped to fully support them and provide all the documentation and traceability they may need.

To date, our customers have not required us to become ISO 13485 certified. However, we have decided to pursue it anyway. We feel that aligning our QMS with our customers’ requirements will make us an even more reliable supplier. It will also differentiate us from our competition. We like that idea.

As we adapt our ISO 9001 QMS to comply with ISO 13485, we plan to implement risk analysis, process validation, and product recall procedures as well as incorporate device master records & device history records into our quality control plans. The end result will be a more robust, hybrid QMS that will enable us to apply for dual certification (we were pleased to learn that our current registrar handles both).

Why maintain dual certification? For one thing, ISO 13485 doesn’t mean anything to our non-medical customers. Secondly, we find it interesting to note that ISO 13485 does not require an organization to demonstrate continuous improvement or monitor customer satisfaction. These are key components in ISO 9001 – components we certainly would not want to dismiss in a competitive environment where things like customer satisfaction and continuous improvement are just a couple of the reasons why our customers keep coming back to Matrix.

Written By:

Anne Ziegenhorn
Document Control Coordinator

Matrix Plastic Products has been micromolding plastic parts since the mid-1990's, long before it was in vogue.  This pusher (shown) for a micro linear cutter cartridge is .031" x .040" x .040" and weighs just .0008 grams.  Most of our micro projects are for the medical industry, for minimally invasive surgical applications in particular, but we also provide micro components used in the electronics industry.  Weighing just fractions of a gram, some of these parts are smaller than a pellet of resin, with tolerances of five ten thousandths of an inch (0.0127 mm) or less.

I believe one of the main reasons we are not intimidated by projects like these is that we also have Matrix Tooling, Inc. under the same roof.  The close-tolerance and high precision of our molded products is rooted in our long history as a designer and builder of close-tolerance and high precision molds.  Our strength in specialty tooling has proven to be a key factor in our evolution into the successful micromolder we are today.

Matrix Tooling builds most of our micro molds with cold runners and low cavitations (8 or fewer) because that combination makes it easier to maintain tight specifications.  While mini hot runners are available, many of the resins we use in micromolding do not lend themselves to hot runner molding.

While almost any thermoplastic resin can be used in micromolding, Matrix Plastic Products commonly uses high-flow, high-temp grades such as LCP, PEEK and PEI.  These materials have predictable shrink, and the high mold temps involved help flow, especially in very thin-walled parts.  They also exhibit superior end use properties such as strength, stress crack resistance, thermal stability and dimensional stability.

Yes, much of our success in micromolding can be ascribed to our mold construction which must be tight and precise, well supported and robust. I asked Steve, one of our experienced moldmakers at Matrix Tooling (but who was new to micro moldmaking) what the key to his first successful micro mold was.  “Trusting our equipment,” he replied.  Matrix Tooling employs only state-of-the-art CNC moldmaking technology.

However, we also subscribe to scientific molding practices.  With a part that you can barely see, it is next to impossible to fill to 95% before transferring; but many other aspects of systematic/scientific molding are rigorously applied here at Matrix.  I will discuss “Scientific Micromolding” in a subsequent blog.

Matrix Plastic Products operates both hydraulic and electric presses in the smaller size ranges, and it is essential that the molding machine be sized according to the job at hand.  But for micromolding, we prefer the electric machines with their inherent precision and repeatability.

On jobs where the actual finished part is barely much more than an add-on to the sprue and runner, not only is the tooling critical, but the Quality Assurance can also be very demanding. Here again, Matrix meets the challenge with such equipment as OGP vision systems, Vision Engineering video microscopes, and a CGI cross-sectional scanner for First Article inspections. Microscopes are a common sight at Matrix: not only in QA, but in the molding, clean room and tooling areas as well!

We don’t “sweat the small stuff.”  Matrix Tooling, Inc. and Matrix Plastic Products has the equipment, know-how and experience to successfully handle any micromolded project.  We’re always happy to offer our insight into yours.

 

Brent Borgerson
Senior Process Engineer (Older Molder)
Matrix Plastic Products
Wood Dale, IL

 

Early in the history of injection molding, molders realized the problems inherent in producing high volume, fast cycling parts of commodity resins with cold runners, especially in high-cavitation molds.  Cold runners can stick or hang in the mold and interrupt or extend the cycle; and often the cold runner being the last part of the shot to set up, can dictate the overall cycle.

It soon became obvious that “runnerless” molding was the way to go.  Early hot runners were of the internally heated (torpedo) type or the externally heated manifold hot runner.  Both were prone to leakage and hard to (especially the torpedo type) change colors with.  Predating these systems were a type of runnerless mold called an Insulated Runner.

Insulated Runners had an oversized internal runner cut into both the top clamp plate and the “A” plate.  This runner was very thick and relied on the thickness of this runner-cull to keep the plastic in a molten state as long as the molding machine was cycling.  The walls of the runner were solid with only a molten center core providing melt delivery.  These led to cylindrical drops (also very thick) and generally to top-center-gated parts.

This system needed fast, uninterrupted cycles to keep the gates open and even momentary interruption caused one or more gates to freeze off.

Startup was also tricky with these molds.  Methods included hand injection of multiple shots into the mold before going to auto, making one big shot and going to auto, or boosting the back pressure way up and extrusion filling the runner cull.

Later the gate drops were heated with a probe which made startup easier and also made keeping the gates open easier, even allowing a brief disruption the the cycle.  With very fast cycles (3 to 6 second range) the heated probe insulated runner can have a fairly small thickness and in some cases, be reground and re-used in the product.

Though sometimes a bit tricky to startup and keep running, these systems could offer advantages over not only cold runners, but hot runners as well.  These include:

  • Quick cycles
  • Less regrind and scrap, though the thick cull wasn’t generally used back in molding
  • The tool was less expensive to build and maintain
  • Less chance for melt leakage.
  • Color changes were very fast compared to hot runners, as the whole colored cull was pulled after the molding machine’s barrel was cleaned. Often color changes can be preformed in 5 minutes with less than 5 pounds of scrap
  • Even if heated gate drops were employed, fewer and less sophisticated controllers were needed.

Yes, the insulated runner is an old technology, but if you have a multi-cavity, fast-cycling job using a commodity resin like PP or PE with frequent color changes, and want a more economical tool that is easier to maintain, then consider insulated runner tools.