Shop Solutions: Automation Focuses Devices on Cancer
When a company touts a state-of-the-art automation system, several images immediatelyleap to mind. Most manufacturers envision large pallet pools, robots loading andunloading machines, or conveyor belts transferring work in progress from one stationto the next.
While these are some of the most common automation concepts used today, none of them can be found at .decimal (Sanford, FL), a medical device manufacturer with a unique business model built around nontraditional automation.
Founded in 1986, .decimal manufactures patient-specific devices including missing tissue compensators, modulators for advanced IMRT (Intensity-Modulated Radiation Therapy) delivery, as well as apertures and range compensators used in proton therapy. The company's most prominent products are compensators that modulate the intensity of radiation during treatment of cancer patients in hospitals and cancer centers.
Compensators are usually made from solid metal, brass or aluminum, sometimes acrylic or wax, which is milled to the size and shape of the specific patient's tumor. Typically, from five to eight compensators must be custom-machined for a patient's treatment, and turnaround time is of the utmost importance once cancer is diagnosed. Through two software packages, one developed internally and one created by Mazak Corp. (Florence, KY), the company has established a unique automation system that allows 99% of its jobs to be shipped within a day of their receipt.
The devices play a major role in improving the quality of life for cancer patients undergoing radiation therapy. According to Craig Stevens, MD, of the H. Lee Moffitt Cancer and Research Institute (Tampa, FL), the use of .decimal compensators has allowed the facility to treat patients that the practice would not have been able to treat otherwise.
Devices are machined from brass, aluminum, acrylic, or wax, and are tailor-made for each patient, focusing the radiation on the cancerous area while protecting the surrounding healthy tissue and critical structures. The goal is to reduce or eliminate the amount of exposure of healthy tissue and maximize treatment to the tumor.
"We take what we do very seriously," says Raymond Mark, director of manufacturing at .decimal. "The quality of our products directly impacts the quality of each patient's treatment. We're always mindful of the fact that we can't afford a single mistake."
A large banner in .decimal's manufacturing section serves as a constant reminder of the impact of its products. The illustration shows an MRI of a patient who received treatment for a tumor that had formed adjacent to the optic nerve. In years past, treatment would have almost certainly resulted in an impairment or loss of vision. Thanks to .decimal's products, the patient was successfully treated with less damage to the optic nerve. Stories like this are constantly reported by .decimal's customers.
Due to the nature of cancer treatment, turnaround time for compensators is critical. Once a patient has been diagnosed, treatment must begin as quickly as possible. Because of this, .decimal strives to complete and ship orders within 24 hr of receipt. The average machining time for a single compensator is 80 min.
Treatment of a single patient requires, on average, five to eight compensators, and every part produced varies in size, shape, and complexity, posing a substantial logistical challenge. Each day brings an unknown quantity of parts of unknown sizes and shapes to be machined. In this environment, process stability and efficiency are imperative.
In its early days, .decimal's manufacturing process began with a doctor submitting basic part information that would be input into an off-the-shelf CAM system. The engineering department would then use the CAM system to generate tool paths and programs that would be taken out to the machines. Parts were machined, inspected, and shipped as quickly as possible, but engineering and scheduling presented significant bottlenecks.
"In the late '90s, we grew to need machines with really advanced controls," says Mark. "We looked around and Mazak was the only company that had a Windows-based control and the processing power we required. At that point, we brought in six machines from their Nexus line to improve our manufacturing processes."
One Mazak model stands out on .decimal's shop floor. Of the 31 machines owned by the company, 18 are the Nexus VCN 510C-II. With productivity-enhancing capabilities, the VCN 510C-II features a 51.1 x 21.6" (1298 x 549-mm) table capable of holding a workload of 2640 lb (1197 kg). Maximum use of the work envelope is provided through X, Y, Z- axis travels of 41.3 x 20 x 20" (1049 x 508 x 508 mm), and a 25- hp (18.6-kW) spindle offers a top speed of 12,000 rpm.
The new machines provided reliable performance and the advanced CNC performance needed by .decimal, but the company still faced bottlenecks in both engineering and scheduling. These could be worked around, but as some of the company's costs began to rise, it became apparent that new process solutions were needed.
"Over 80% of our parts are made of brass, and the cost of that material has gone up by as much as 400% at certain times over the years," says Mark. "The amount we're able to charge is set by the health insurance industry, so we really have to be innovative in coming up with new ways to be lean."
In late 2007, .decimal initiated a significant change in its processes that would redefine its operations. Internally, the company developed proprietary software to automate its engineering functions. Simultaneous with that software's development, .decimal met with Mazak and explained its bottleneck issues. Neil Desrosiers, a software specialist at Mazak, began the design of a new scheduling program to manage workflow among the 31 machining centers in .decimal's facility.
The engineering and scheduling softwares came online within a month of each other, and had an immediate effect on productivity. Today, the flow of work through .decimal's facility begins with the receipt of files from radiation oncology facilities across the nation. These files are taken from an MRI or CAT scan and uploaded via .decimal's Internet-based ordering system. Cutting data are automatically generated by .decimal's proprietary software, and the job is placed into the program created by Mazak. A user then simply drags and drops the job onto the machine it should be sent to on the shop floor.
The 31 machines on .decimal's floor are run by just three operators, although a five-person quality department is utilized to maintain a high level of quality for every device manufactured. The manufacturer is an ISO 13485:2003, 9001:2000 and 14001:2004 - certified company. To maintain certification, .decimal must pass four stringent audits each year to verify that the company is conforming to all of the requirements of each system. Additionally, the company must also adhere to the FDA's mandated Federal Code of Regulations for medical-device manufacturers.
The company provides an intensive training course, internally referred to as l.d, or learning.decimal. New operators are taught the process for loading and unloading parts, and automation handles the rest. Once the operator loads material to be machined and hits the start button, the machine cuts the part to completion and uses a Renishaw probe to verify machining accuracy. Mazak's Voice Advisor feature notifies the team of operators when a part is finished, at which point it is removed and transferred to shipping, and the next job is loaded.
"We've always had a goal of sameday shipping on all orders received before noon," says Mark. "With the old system, we were never able to achieve more than 65%. Thanks to the automation we've implemented, we're now hitting 97% same-day shipping for all orders received before noon. When you consider that we're running between 125 and 200 parts a day, all of them unique, that's really quite a testament to the software and our Mazak machines."
Armed with the simplicity afforded by automating its engineering and scheduling, .decimal is in the beginning stages of international expansion. The company has received CE Mark approval to sell products in Europe, and is going through the regulatory approval process to begin marketing in Japan. Ideally, once order quantity becomes great enough, it will have remote manufacturing facilities with .decimal software and machinists. Everything else will be managed from the company's headquarters in Sanford, Florida.
Tools Up Component, Mold Production
Manufacturing products at the highest quality levels in the competitive cable accessories market requires optimization of every tool and method in the manufacturing process.
Elastimold (Hackettstown, NJ), a division of Thomas & Betts and a leading producer of premolded cable accessory components worldwide, meets these challenges every day at their 250-employee, 100,000 ft2 (9290 m2) facility, and a nearby R&D Center in New Jersey, employing another 30 people.
Elastimold products use specially formulated materials with 100% peroxide-cured insulation and shielding, and are offered with 100% factory-tested assurances for durability, quality construction, and non-degrading, highly reliable, and maintenance-free performance.
With a guarantee like this in a highly competitive market, the company recognizes that manufacturing processes must be extremely efficient. Elastimold faced a new challenge when the manufacturer made the decision to add a commodity-type part, a low-voltage secondary underground aluminum connector that distributes voltage to residences, to its production capabilities.
Because the connector is a mass-produced part, the company needed to produce it reliably within seconds at a volume high enough to be competitive. The aluminum (T6-6061) connectors required 0.75" (19-mm) holes for wire ports and perpendicular to each of these, 11/16" (17.5-mm) threaded holes.
Elastimold approached its machine tool manufacturer and drill manufacturer first to investigate processing options. The thread milling, drilling, and machining processes needed to work together seamlessly in order to produce the application correctly. The machine tool manufacturer then contacted Emuge Corp. (West Boylston, MA) for a threading solution.
Initially asked to provide a tapping solution for the application, however, Emuge technical experts determined that thread milling was a better alternative. Emuge's Thomas Kowalski explains: "In this particular aluminum part application, taps would wear more quickly and costs would be higher. Also, the machinist would need to keep a closer watch on them for breakage."
Thread milling was recommended by Emuge. Thread mills provide controllable, easily removed chips, and produce high-quality threads. Although the machine-tool vendor was hesitant to try the thread mills, Emuge sent them a thread mill along with a program, which included the required speeds and feeds and specifications for required high-pressure coolant.
"The results were excellent," says Kowalski.
Robert Fong, project engineer at Elastimold, explains that cooperation of all three process disciplines was needed for success: "Not only did our machine-tool vendor have some initial reservations about this application, our drilling vendor was tentative about making a recommendation. They didn't believe their drills could run fast enough for our application. We urged them to work with Emuge and our machine-tool supplier to achieve the desired results." By consulting all three experts, it was proved that the part could be produced to meet Elastimold's requirements.
The first Emuge thread mills used in Elastimold's aluminum connectors application were standard type GSF and GF coolant-through tools with a TiCN coating. As the application evolved over time, so did the threading solution. Emuge supplied Elastimold with two customized thread mills. They included a 1/14 GF type D20 x 50 x 120-Z5 TiCN IKZN optimized for 1-14 UNS 2B threads with IKZN radial coolant feature. This feature allows coolant to exit the flutes to eliminate waste and evacuate chips efficiently in both through and blind holes. The second type of thread mill supplied was a 1/16 GF type D16 x 32 x 100-Z5 TiCN IKZN optimized for an 11/16-16 UNS 2B threads.
To facilitate quick tool changeovers, two HMCs running in tandem offered redundant tooling for this application.
Further customization of the thread mills by Emuge has increased throughput and reduced the time to make the aluminum connector by up to 90% of the original goal. Fong continues, "We are seeing more than a 15% increase in productivity since production began. We now have a completely turnkey operation, running lights-out, day-in and day-out."
After the success of the thread milling solution, Elastimold turned to Emuge for its cutting tool expertise in another area—end mills for moldmaking. Elastimold designs and builds its own rubber injection molds for medium and high-voltage connectors. Again, the challenge was to bring the connectors to market as quickly as possible.
The company had been producing about twelve molds a year, but thought they could improve their output. Emuge representatives reviewed their milling operation and agreed. So, in 2007 Elastimold was invited to the Emuge Technology Center to see first-hand how Emuge could improve their moldmaking process. Up to this point, Elastimold had been using a variety of different carbide end mills that they purchased from a local distributor. It had been taking the company about one week to manufacture the sample mold cavity half.
Although Elastimold currently has a three-axis machining center inhouse, they anticipate having a five-axis system shortly, and took great advantage of the expertise available at Emuge's Technology Center. Fong and his team put Emuge to the test to work on their rubber injection mold application using the increased capabilities of a five-axis machining center.
Emuge demonstrated how to use precision-ground round insert end mills on a pre-hardened block of H13 RC 52 material to show the time savings with hard milling versus the traditional roughing soft process and then finishing hard. This entire moldmaking process, including roughing, machining, and finishing, took 5 hr, eliminating the need to send the block out for heat treating during the middle of the process.
Returning to New Jersey, Elastimold was able to follow a similar process on its three-axis machining center using the Emuge Time-S-Cut system, a high-productivity insertmilling system. They were able to take a soft block of H13 material, rough it out, heat treat it for hardening, and then finish-mill it in about 4 hr versus the 40 hr this process had been taking. The substantial productivity gains were possible because the Time-S-Cut system is capable of extreme chip loads and aggressive material removal.
Before using Emuge end mills, Elastimold was designing and building about 12 molds per year. Now they are manufacturing 16.18 molds annually. "The improved process time is due to the implementation of Emuge end mills," says Fong.
Coating Gives Valves a Better Grip
Manufacturers of sand-cast parts know how difficult it is to achieve a rigid grip on oddly shaped products during machining. At the same time, it is imperative for chucks and fixtures to maintain a solid, stable hold on castings to allow speedy and consistent machining operations.
Industrial valve manufacturer United Brass Works (United; Randleman, NC) has found that adding an electro-fused carbide coating to their fixtures and jaw chucks can help achieve an optimal grip.
Many of United's products are made of cast brass, iron, or steel. Workers used to encounter more slippage problems than one would find in a plant that uses square blocks of metal, rolled steel, or bar stock.
"When we have to grab a product in a chuck or a fixture, the ability to hold it perfectly rigid is impacted by the variations in the cast surface," Mike Berkelhammer, United's president explains: "Just squeezing harder isn't the answer. At some point, you're going to deform the part you're holding. So the idea is to get a good grip without adverse pressure. We therefore use some kind of a gripper material in or on the jaws to prevent the part from moving while it's being machined."
Berkelhammer says jaws can be used without grippers, but the part is less apt to be held firmly. He felt his choices of adding texture were to insert anti-slip pads or apply a carbide coating. United had been using carbide gripper pads, but was still having slippage problems, and was unhappy with their overall performance in some applications.
Applying carbide coating onto the jaws was United's next move. A few jaws were shipped to Carbinite Metal Coatings (Butler, PA) for coating with the Carbinite carbide alloy coating, which is metallurgically bonded to tooling using a process called electrofusion. The primary function of Carbinite is to increase the coefficient of friction between jaw and workpiece, with a secondary benefit of wear reduction.
In the end, Berkelhammer found the coating to be a better, easier process for reducing slippage in the machines. "The texture of the coating gives us little biting edges, without biting in too deeply. It allows for much more rigid control of the part that we were grabbing."
The reason for this additional control is because of a process that Carbinite's President Rob Freyvogel calls surface micro-keying. He explains that the coating creates many small peaks that penetrate the workpiece surface. The two surfaces, in this case the coated jaw finger and the castings, are keyed together upon clamping.
"Another advantage is that by using the process we can select the texture that we want," says Berkelhammer. "In parts that we still need to hold solidly, but don't want to cause large blemishes on the surface, we select a finer texture. For those metals that are harder, or for those parts where the surface finish isn't important, we can be more aggressive. In any case, there are fewer markings with the Carbinite than there is with carbide gripper pads."
Another benefit of Carbinite is that it can be coated across the entire surface area of a gripper; whereas gripper pads have limited contact areas where they can effectively grab a part. This additional surface area decreased wear caused by friction over time.
The electrofusion application process creates such a strong bond between the steel base metal and the carbide that flaking and chipping don't occur. The process fuses the coating into the jaw, rather than spraying or painting it onto the jaw.
Berkelhammer points out that using a coating had cost-savings benefits as well. "We save time because when we use carbide pads we have to machine the jaws to accept them, and we have to insert them. Generally speaking, we have to change them. We have not had that issue with the Carbinite."
Carbide gripper pads still have their place at United, particularly on older jaws that were made without allowance for the thickness of a coating. Grippers are also still used for jobs where the castings have so much variation in roundness that the more aggressive shape of the points on the grippers make up for variations in part shape.
This article was first published in the July 2009 edition of Manufacturing Engineering magazine.