Micromolding market opportunities are expanding. For this article, we asked micromolders and micromoldmakers if equipment was good enough, whether it could be improved, and how turnkey systems would help. Also, suppliers tell us what they have to offer

Are today?s micromolding machines good enough?Scott Herbert, general manager of Rapidwerks LLC (Chicago, IL) is satisfied with his micromolding press. ?For today?s technology, yes, they are good enough. The need is there and the opportunities are, too,? Herbert says. Rapidwerks runs a Battenfeld Microsystem 50.Stu Kaplan, president of Makuta Technics agrees, saying, ?Yes, and they are getting better.? Kaplan should know. He has an inside track on micromolding press developments. Makuta Technics is a member of a multinational group of companies that specializes in micromolding and micromoldmaking?the Sansyu Group with global headquarters in Takahama-City, Aichi, Japan.

?Our sister company, Sansyu Microtechnics, is involved in the development, prototyping, and field testing of all the Sumitomo singleshot and doubleshot micromolding machines?those with less than 30 tons of clamping force,? says Kaplan. ?Sumitomo continues to improve every aspect of its machines?from the software to the screw and barrel systems.?

All-Electric Thumbs Up

Another micromolder who?s bullish on today?s microtechnologies is Paul Fink, president of Microprecision Products (Rancho Santa Margarita, CA), a company with roots in California?s Silicone Valley. Fink says, ?Our exposure to development of the semiconductor industry, computer memory storage devices, and minimally invasive medical devices fostered our involvement in tooling and micromolding.?

He believes great strides have been made in the development of hot runner systems and hot tips for micromolds, as well as in electrical discharge machining (EDM) refinements that allow manufacturing the micromolds themselves.

And, as far as micromolding machines go, Fink says all-electrics have provided an unprecedented wealth of control not previously available.

?Real-time feedback for the injection units and the accurate metering of microsized shots of material are key to successful production. With wall thickness down to a few thousands of an inch and gate diameters of .003 inch, the pressure control necessary to usefully fill micromold cavities becomes much greater.?

Material has to be delivered so that it won?t damage sensitive cores and mold details. That?s one reason Fink says the control all-electrics provide is critical. ?The pressure of the nozzle up against the hot half of the mold becomes more significant, and the speed by which the material is delivered has increased quite a bit.?

Reserving Judgment

Others are less enthusiastic about what?s on the market. Lynn Momrow, managing partner of Extreme Molding LLC (Watervliet, NY), finds the choices available to be very limited. ?Basically, for the materials Extreme Molding works with, such as silicones, PEEK, and PFA, we have very limited options?the Sesame and the Nissei, maybe the Toshiba.

All of these machines have short track records, and the suppliers are reluctant to guarantee that they will work adequately to meet the tight tolerances typically needed with micromolded parts. The biggest issues for us are clamp force and feeding accuracy.?

Donna Bibber, VP of Miniature Tool & Die Inc. (Charlton, MA), says that because micromolding is still relatively new, machine manufacturers today are not as adequately prepared to support the technology as they are with their more conventional products. ?Micromolding machine manufacturers need to gain more experience with current applications being tooled to better promote their equipment,? says Bibber. ?Expanding the knowledge of personnel directly involved in parts applications will help the situation when problems arise. There?s a problem, though?most of this kind of knowledge is a protected asset among micromolding specialists, and is not being shared.

?Micro machines have come a long way, but I find I am limited on materials that will run with very small screws,? says Mark Rackley, president of micromolder Stack Plastics Inc. (Menlo Park, CA). ?Extremely viscous materials may break a screw or auger during the plasticizing process. We need to be able to run engineering grade resin.?

How can micromolding machines be improved?

Ironically, Miniature Tool?s Bibber says that one aspect in the design of these small machines that?s crying out for improvement is they have to get bigger, at least in one area. She says the machines need to provide more mold space for larger molds and to better accommodate side actions and hot manifold systems. More mold space also is required for automation, part removal, insert placement devices, and optical inspection systems. In addition, more room should be made available for water lines and electrical connections. MicroPrecision Product?s Fink also believes more attention must be paid to tooling requirements.

?Benchtop micromolding equipment may satisfy the R&D or the prototyping needs of micromolding,? he says. ?However, when the requirements have tooling with multiple cavities, slides, or movements within the tooling, as they often do; when specialized heating and cooling requirements are involved; and when guided ejection and taper locks are called for, the micro tooling is no longer ?micro? in size and will not fit into the benchtop-sized molding equipment.?

The weight of the production tooling plus the increased mold base size require accuracy across the mold?s parting line, says Fink. That means robust tiebars are required?four bars, not two, he says. More daylight between platens also is called for and that, he says, rules out most, if not all, benchtop micromolding presses.

More Space, Less Space

Empire Precision?s Elli agrees, saying, ?Improvements could be made in the size of the platen vs. the size of the shot.?

However, Rapidwerk?s Herbert is satisfied with his Battenfeld Microsystem 50: ?The MS50 is an uniquely engineered machine. It?s well balanced and does not compromise in the areas of tonnage range, clamp design, injection-unit design, or process control. And its footprint is of the size that all the others use as a benchmark. It?s uniquely balanced and accepts micromolds extremely well.? Speaking of footprints, Makuta Technic?s Kaplan does believe the footprint of micromolding machines could be somewhat improved?downsized that is.

Price and Delivery

Delivery times also could be better, says Bibber. ?An average delivery for a micromold is about eight weeks. An average delivery for a micromolding machine is 16 weeks, because they are not stocked items, and many need to be ordered and imported from overseas manufacturers.?

She says that this leaves a wasteful lull in the development of new micromolded products and often requires micromolders to have a research-ready machine at their facilities, as part of a ?build-it-and-they-will-come? mindset. Extreme Molding?s Momrow adds the press pricing to the equation.

?Time and price of machines are not acceptable to most customers?we have been quoted six to eight months for a machine and prices that are typically well over $100,000,? Momrow says. ?This makes them a stretch to justify over just adding a tabletop feeder to an existing small-tonnage electric machine, and going that route, particularly when there are no data to support accuracy advantage of investing in such expensive machines.

?So,? she says, ?lower prices, quicker deliveries, and all-electric versions with higher accuracy feeds are required in my opinion.?

Technical Glitches

Stack Plastics? Rackley sums up a key problem area he?s encountered in all-electric micromolding machine design in one word: ?Heat!?

?Some materials run so hot the servo?s performance is affected by the increased temperature in and around the molding machine. This needs to be taken into account. There is no problem if you?re molding ABS, styrene, PE, or something like that. But just try throwing some PEI in the mix!?

Rackley also says today?s micromolding machines could use better mold temperature control: ?Machines should be equipped with electric controllers, as well as hot- and cold-liquid control, from 30 to 300F.?

One source that wishes to remain anonymous says it is tough for molders to say whether equipment could be better, for a perfectly understandable reason. Most micromolders have purchased only one manufacturer?s product, and only know what they like and don?t like about that particular micromolding machine line.

?Some like one OEM?s latest models, because of their compact design?their self-contained chiller, in particular?their very fast cycle times, and their mobility. Others say there?s not enough mold space available in this model and whine about its long delivery times.?

It?s Not The Machine

Our anonymous source continues: ?Others like the expanded velocity profile and control of another OEM?s press, and the space in-between the tie bars for larger side actions and with no shot size compromise. They also have a ?no check ring? design, which won?t show wear over time. Their challenge is that they are relatively new to the injection molding market and have some work to do with marketing themselves in plastics vs. the machine tool industry, which they are most used to.?

?In the case of another system, customers like the self-contained, soup-to-nuts mentality covering part removal, packaging, and inspection all in one system,? anonymous says. ?But others don?t like the long system lead time and price.?

Hubert Lorenz, GM of the Swiss micromoldmaker Mimotec, says this: ?Micromolding is not a matter of the machine?even a machine like the Battenfeld Microsystem 50. It is more a matter of molding knowledge and micromolds. If both are done well, it is possible to inject 24 micro cavities in parallel.?

Should machinery suppliers offer full turnkey systems with their micromolding machines, including auxiliaries?

Empire Precision?s Elli?s answer is a conditional ?Yes.? His condition? ?Only if they can offer them cost effectively,? he says.

Makuta Technics? Kaplan also answers yes to this one, but he brings up a point of major importance to custom micromolders. That is, the only thing that doesn?t change for custom molders is changeover: ?Some turnkey systems, such as Battenfeld?s Microsystem 50, limit the flexibility we need,? he says.

Even Rapidwerks? Herbert, who runs a Microsystem 50, says flexibility is a must: ?Ideally it would be nice to have a generic package. But, truth be known, each production opportunity is unique and modifications are often a given.?

?The problem with turnkey solutions, from Stack Plastic?s perspective, is one of flexibility,? Radley says. ?We are custom molders and need solutions that involve many different mold and part configurations.?

Needy Newbies

Miniature Tool?s Bibber says the turnkey-systems approach can be valuable, especially for newcomers to the field.

?We have recognized the need for such systems and in the past year we have sold four turnkey systems complete with customized drying applications, micromolds, and micromolding machines. We completely debugged them here at Miniature Tool and shipped them to various locations throughout the U.S. This fills a need for molders who haven?t yet gotten their feet wet with micromolding and provides them with a solution that starts them in the right direction. As the industry grows, this need may or may not subside.?

Turnkey systems, she says, also can help bridge knowledge gaps, while simultaneously keeping top secrets secret: ?Again, because there are not many people sharing the wealth of knowledge in this field, more micromolders or OEMs with microscopic parts will require turnkey solutions, at least for the short term.?

?This fills a need for project confidentiality, as well,? she says. ?Today, most OEMs and research companies order a molded product from a customer, who in many cases sends out the mold to another company to build. Customers with microparts worry about too many sets of eyes seeing their new and innovative approach to existing products, or to existing manufacturing methods.?

As far as what?s needed in individual auxiliaries, MicroPrecision Product?s Fink believes dryers need to be downsized. He says the smallest dryers now available, models with 10-lb/hr throughput, are still too large.

?Some of the materials being utilized by the medical device industry are very costly. Bioresorbables are one example of costly materials that, when processed for micromolding, sometimes fail to reach the end of the dispersion nozzles of current hopper dryer configurations. This leaves the micromolder to modify or fabricate specialized equipment,? he says.

Stack Plastic?s Radley says more work needs to be done on product handling systems. After all, handling parts smaller than a plastic pellet can be a daunting task. ?The best situation would be to not have to touch the part, ever,? he says.

?Product handling equipment?existing robot designs and conveyors?are not equipped for the needs of true micromolding, that is, parts with weights in the subhundredths of a gram range,? says Fink.

?Static becomes a significant nemesis of the micromolder. I believe static-removal devices will be offered by molding press manufacturers in the near future as a solution to this problem.?

Vacuum-filtered robot EOAT today is ?left to the imagination and custom fabrication of the micromolder,? Fink adds. ?Overall, the support equipment for successful micromolding has come a long way, however, there is much room for continued improvement before we can enter the next stage of nanoparts development.?

However, Extreme Molding?s Momrow says suppliers should concentrate their development efforts elsewhere, before moving downstream: ?I think suppliers should focus more on producing robust, high-quality micromolding machines. The requirements for secondary processing add-ons will come over time, but we need good, basic machines first.?

Please look for featured micromolding machinery in the product section of the website at www.pma-magazine.com/product_news/.