Vertical Machining Center Designed for Moldmaking Alongside Metal 3D Printers Brings Virus Face Masks to Market Quickly

At the start of 2020, Ben Staub never would have guessed that Bastech Inc. would be a personal protective equipment (PPE) manufacturer. That was not the plan. However, COVID-19 changed all of that, and for the better. Not only was this small manufacturer able to produce desperately needed face masks due to its 3D printing, machining, tooling and molding experience, it also launched a new product line. And, the company’s machining technology was a significant contributor to this rapid growth.

Staub is president and owner of Bastech based in Dayton, Ohio, which employs a team of 28 people across a 22,000-square-foot manufacturing facility producing low-volume plastic injection molds and investment castings for which Haas machine tool technology has been essential.

Bastech has been a Haas customer since 1999, the same year the shop purchased its first Haas VF-3 vertical machining center, followed soon after with a Haas VF-0 vertical machining center. The shop also houses seven different AM technologies—from stereolithography to multi-jet printing—via a full polymer lab, wax printers for investment casting patterns and three metal printers.

They use a small 3D Systems Pro-X 200 and two large Concept Laser M200 dual-laser systems based on powder bed fusion (PBF) technology. One of Bastech’s three printers is dedicated to aluminum and the other two run a wide variety of metals. For moldmaking, they use a lot of maraging and 17-4 stainless steel because they can be hardened.

The demands to produce a large amount of P20 pre-hardened tool steel (34 HRC) and aluminum tooling very quickly for PPE drove the decision to purchase a new Haas VM-3 moldmaking machine.

“The VM-3 just made a lot of sense for us,” Staub says, “The higher efficiency machining, wireless intuitive probing system and extended y-axis come in handy for a variety of projects, and the high-speed features improved surface finish, reducing secondary polishing.” In addition, he notes that the VM-3 enables the shop to move a lot faster with its through-the-spindle coolant and control of chip size, and its contouring capability helps to manage their volume of laser scanning work.

Even so, Operations Manager Scott Young says it’s all about accuracy. “Accuracy is really what we’re looking for with the Haas VM-3. We want highly accurate and fit areas. We’re machining parts with tolerances of plus or minus half a thousandth. That’s a tight tolerance for mold work, but the Haas VM-3 handles it.”

 

Making Masks

The pandemic put many manufacturers to the test as teams jumped in to help produce various PPE, including Bastech. However, in this team’s case, they decided to develop their own mask system and under a new company.

“When COVID-19 hit and the news about the inadequate results of some 3D-printed, and low-volume-produced masks surfaced, we came up with our own product line called P-Tech for protective technologies and developed our R and S series of masks,” Staub says.

Staub and his team came up with a thermoplastic elastomer mask system with an overmolded cartridge insert. “Our design is cost effective and offers a complete seal around the outside to prevent the leakage many users of traditional N95 masks often experience. Plus, the filter system is disposable and our thermoplastic elastomer is a material proven for resuscitator bags. So, you can put this mask in the dishwasher to clean it or wipe it with isopropyl alcohol and put it back on,” Staub says.

Bastech received a grant for this project—like other manufacturers—that helped them purchase the new equipment and to help solve the PPE shortage issues. The Ohio Development Services Agency awarded the grant for reshoring PPE to be manufactured in the state of Ohio.

 

Dual Approach to Making Molds

To quickly make the molds to produce these masks, Bastech opted to take a two-process approach the shop was tooled up to do—additive and subtractive manufacturing. Bastech started the original prototypes for the R series masks on its existing Haas VF-3 and the VF-0 vertical machines, but when they needed to take the project into production, they added the Haas VM-3, which is designed specifically for moldmaking, yet offers Bastech versatility to take on a variety of work.

It’s mostly traditional cavity and core milling. Some they produce additively and then perform secondary machining for seal-offs or finishing part surfaces and ribs. Basically, they use the other VMCs to machine the tooling and ejector plates and use the VM-3 to finish the cavity work.

Staub explains that when you have an open cavity, doing almost all of the geometry on a mill is the best way to go, especially with what they can now accomplish with the high-speed VM-3. But, if the mold has deep ribs or requires a lot of EDM work or sharp corners, then additive is the way to go.

With additive manufacturing (AM), Young wants to get a shape that only requires polishing before it goes into the mold. Bastech is creating a hollowed-out effect to minimize the necessary amount of material and processes.

Simply put, they don’t want to machine if they don’t have to. In some cases, the team may have to machine a tight-tolerance area, which is where the Haas VM-3 comes into play. “We often build the part upside down purposely, so we can machine it on the build plate before we take it off the plate and finish the other side,” Young says.

For example, using additive metals, Bastech was able to build a lifter that is fastened to the ejector system of the mask mold with solid rods. “The lifter is holding the filter in place so that we can mold a rim around it for the seal,” Young says. “We want the lifter to be light, so we hollowed everything out. As a result, it uses a very minimal amount of material.”

Bastech has completed the majority of the product development as far as forming the filters, the design, prototyping and plastic injection mold build. They also changed from hydraulic presses to a new fully electric, 270-ton Sumitomo injection molding machine dedicated to this product line, which runs four cavities of the masks at one time. “Every 30 to 50 seconds, we are dropping four masks for mass production,” Young says. Moreover, the company sold the mask to a local hospital. 

They are now working on decorating techniques for personalizing the mask systems as well as some accessories, including a snap-on face shield, another filter system option and a SAL valve to enable its use for applications like sandblasting where the user is not concerned with filtering the exhalation, only about filtering the inhalation.

“The accuracy, speed and cooling capabilities of the VM-3 fit nicely with our additive technology, yielding quality precision parts for our customers—whether that is an injection mold, a wax mold or piece part production. We can do all of it,” Young says.

Bastech is even getting to the point where the team wants to start challenging the VM-3 to see how fast they can push it and to start running more lights-out manufacturing. “We want to keep pushing,” Staub says.