Times have changed though, and the necessity of quick time to market and short product lives have shrunk lead time, while demanding resins and complex part geometries have dictated that robust and precise molds be built in much less time than in the past.

These shortened lead times are where technology has really stepped in to help. The crusty moldmaker has been replaced by a technologically savvy leadman, and each stage of the mold building operation is done under the control of specialized operators who are completely versed in the technology of their stage of the operation.

All steps of the mold building operation (design, steel milling, electrode cutting, wire and sinker EDM operation, turning, and grinding) are Computer Numerically Controlled and connected via a local area network. Many of these operations are palletized and robot attended, enabling lights-out operation to further reduce time to delivery of the finished mold. Direct access to 3D design models is available to every operator at every phase of operation. Time-tested standards like prints and setup worksheets are becoming a thing of the past. Even the progress of jobs and tracking records are maintained electronically.

Matrix Tooling, Inc. is now thirty years old. Having seen the mold shops of even twenty years ago, it would have been hard to imagine that today’s machining centers with their brightly colored computer displays, robotic arms, and servo motors have any relationship with the mold shops of the “old days” where craftsmanship was king.

But there’s no doubt craftsmanship still has its place. We’ve spent the last thirty years blending the best aspects of traditional mold making with state-of-the-art technology to produce a precise, top quality and robust injection mold as quickly and economically as possible. The first paragraph of the Matrix Tooling quality policy reflects this: “Matrix Tooling, Inc.’s mission is to combine traditional craftsmanship with state-of-the-art technology in designing and producing the highest quality injection tooling and molded products.”

Our team members have found the key to successful mold building and we take great pride in combining the latest technology with old-time craftsmanship into every build. Though the mold building business has evolved each team member takes the same pride in our end product as the crusty old mold maker with the denim apron.

Written by:

Brent G. Borgerson
Senior Process Engineer (Older Molder)

I know that the U.S. is not the only country with this problem. Much of Western Europe suffers from the same shortages. Many look down on those who work with their hands, but eventually, someone will need to learn and become the next batch of journeyman plumbers, electricians, toolmakers, etc. If not, homeowners better get ready to learn these skills or be ready to open up the checkbook.

I read an interesting article back in the mid 1990’s. In Germany (where an apprenticeship in a trade is still considered a viable career choice), the graduating number of architects outnumbered the number of apprentices from all skilled building trades combined. Think of how many architects it takes to build a home versus the number of workers needed from the various trades, and you’ll realize that something is seriously out of whack. Apparently the Germans, too, have spread the word that working behind a desk versus working with your hands is the way to go.

Hitting closer to home, we’ve struggled with finding quality candidates. Toolmakers today require skills far different than what was needed prior to the computer age, and the fact that few are training today makes for an unsustainable labor situation.

Written by:

Paul Ziegenhorn
President

I remember when I first started working with robotics on molding presses. Back then, they had to be adjusted by climbing all over the robot, and the programs were only capable of the basic “L” and “U” movements. In many cases the drop zone location on the up and down movement had to be set the same as the pick location on the up and down movement. The presses would have a mechanical stop to hold the mold in the open position and an alignment pin above the locating ring on the front half to verify that the mold was perfectly aligned each and every time it was set in the press. Even with this it was a challenge to keep everything aligned. It was also very important for the oil temp to be correct at startup. Old hydraulic presses would not open to the same distance or eject the parts correctly at the wrong oil temperature. You would need to re-adjust after running for a few hours or even days. It was an ongoing battle keeping everything lined up. The robots had pneumatic up and down movement with a servo drive existing only on the traversing and kick movements. For something designed to make a processor’s life easier they certainly brought their fair share of pain!

But like all newer technologies, issues were addressed one by one and improvements came out consistently. We now have servo movements on all three axises, with options for rotation and flip servos as well. We are able to tie the robotics directly into the process monitor on the press and automatically divert parts at startup and any time the process parameters move out of tolerance.

We continue to install alignment pins on the front half of the molds but the newer presses hold the open position / ejection forward position much better (especially newer electric presses). Now robots have evolved from the painful era of trial-and-error setup to a nearly scientific setup and operation.

I have worked with many different models and brands over the years and have been lucky to have worked with some of the best built and best supported robots on the market. Recently I attended a Flex Teach class for Yushin robots. The Flex Teach system allows the user to create motion programs for the robot using a personal computer. The same programs can also be modified using the touch panel controller. What I like best about the Flex system is that it utilizes the PC as a training tool for the robot when it is offline. This can save countless hours of down-time and allow operators that would not feel comfortable practicing on a live press to start learning the Flex Teach system. Just knowing that they won’t have to worry about damaging expensive molds or end of arm tools (or more importantly, themselves and others) opens the doors for every operator to catch up to speed.

Even robotic systems from just a few years ago were no comparison. They, too, were fully programmable and also had servos with CNC type controllers, but these models required hundreds of command lines and an extensive knowledge of the programming language to run. The program itself consisted of several parts: a run program, reference program, and home program for every job. Making adjustments to a program became a trial-and-error nightmare. More importantly, valuable press time was lost in the mix. Considering today’s shortened deliveries and 24/7 production jobs, fiddling with the programs is something most molders can live without. I wish I could have done some of the work offline with a program tool like the Flex Teach system. We now have the ability to take our time (with minimal pressure) and do most of the programming offline while the press is still running.

With the old system, programming mistakes would have to be caught during the standard process of verification referred to as “stepping through the program” and tweaked accordingly. The Flex system allows us to run the program or changes through a simulator and verify that it looks good on the computer screen before being transferred to the press via a SD memory card and loaded onto the robot. For good measure we continue to step through the program to verify a second time, but there is no doubt this saves time in the process.

All of these new features have made robots perform more consistently and adds to their versatility, performing tasks like sorting, de-gating, counting, boxing, and stacking. Robots can even place small inserts and verify their placement these days.

So molders, learn to love your robots. They work tirelessly, exactly, and without a complaint or absent day. They can be a molder’s best friend (though you can still keep the dog). Yes, robots surely have come a long way!

Written By:

Pat Collins
Molding Operations Mgr.

Performing first article inspections with these methods can be particularly time consuming and labor intensive. In addition to creating fixtures for each setup, the parts often need to be “sectioned” (sawed, cleaved, ground down) in order to inspect internal dimensions that are not naturally accessible via a touch probe or optical scope.

The associated tasks may require an inspector with a high skill level and/or experience performing similar procedures. It also opens up additional steps where operator bias and other errors can be introduced. Were all cavities saw cut and treated the same? Do different inspectors reproduce the exact same setups?

Above that, the sectioning process itself is inherently flawed. Sawing a plastic part to access a cross section will almost certainly introduce its own level of error, and this error can often exceed the tolerances of the dimension and distort inspection results. Warp, burrs, rolled edges, inaccurate trimming, inaccurate positioning of the section line and melting are all possible byproducts of manual sectioning methods.

And after all is said and done, you end up with first article data that is historically limited to the original points in your inspection layout. If you want to go back later on and inspect any additional dimensions, the setup will have to be recreated with the original parts.

To sum it up, performing a first article inspection (FAI) on complex parts often comes with the following issues:

• Time consuming & labor intensive
• Require highly-skilled technicians
• May introduce operator bias
• Allows for subjectivity in results depending on operator
• Historical reference data is limited to inspection points taken from original sample parts, making any future inspections from those samples very time consuming and possibly inaccurate.
• Requires inherently flawed sectioning process which can introduce error that exceeds dimensional tolerances (warp, burrs, rolled edges, trim marks, melting)

This is where cross-sectional scanning (CSS) comes into play. CSS is a unique process developed by CGI of Eden Prairie, MN. It offers an automated alternative to traditional first article inspection techniques that provides consistent and objective results. Using reverse engineering principles, CSS begins with an actual part and rapidly deconstructs it, cross-section by cross-section, to create a comprehensive set of measurement data capturing every dimension on every surface of the part, both external and internal. This video demonstration of the Cross-sectional scanning process will help clarify the process.

In the end the CSS capability reduces the amount of time and labor required for inspections, nearly eliminates operator bias and human subjectivity from the process, minimizes the dimensional stresses caused by manual sectioning, and leaves you with easily retrievable, electronic historical data that can be interrogated at any point in the future.

Posted by:

Gary Johansson
V.P. of Quality / Regulatory