CAM Software/Machine Matchup Save Time, Boosts Efficiency
CAM Software/Machine Matchup Saves Time, Boosts Efficiency
A five-axis machining center and better CAM software helped this mold shop dramatically improve throughput and profitability.
M.R. Mold and Engineering Corp. in Brea, California, is known for its expertise in building molds for liquid silicone rubber (LSR) and gum stock (also known as high-consistency rubber). Recently, the company invested in two tools that together, it says, have helped to dramatically improve throughput and profitability in its manufacturing process: a five-axis machining center and better CAM software.
Because working with silicone is inherently more difficult than working with plastics, M.R. Mold created proprietary cold runner systems that offer customers cost savings through shortened cycle times and less material waste. Until last year, it used its EDM and three-axis machining centers to manufacture the silicone molds, but company President Rick Finnie knew that to cut job times and increase efficiencies it needed to invest in a five-axis machining center. After researching several options, the shop purchased a Yasda YBM Vi40.
“I was looking for a machine with the ability to perform very-high-accuracy machining of cavities with very complex details,” he says. “The Yasda met my requirements, and could do it quickly and efficiently.”
Previously, Finnie’s machinists were using long cutters in its three-axis machine to reach the deep cavities and then would EDM the detailed features required by customers. This was a time-consuming and costlier process, lead programmer Nhut Nguyen says, because long tools are prone to chatter when cutting in hard materials. The chatter caused the long cutters to wear faster, and Nguyen would often have to stop in the middle of machining to replace them with new ones. With five-axis programming, the machinists can now use shorter cutters that can more easily reach and machine tight areas. In addition, the shorter cutting tools made possible by the five-axis machine also significantly reduced the chatter and minimized wear on the cutters, and they have improved surface quality so that finished parts require little, if any, handwork. According to Finnie, machining time was reduced by as much as 20 percent.
Finding the Right CAM Software
Once the Yasda machining center was ordered, it was suggested to Finnie that the current software used at M.R. Mold was not going to be adequate for driving this high-speed five-axis mill. Jeff Johnson, tool die/mold product manager at Yasda distributor Methods Machine Tools, recommended that the company reconsider the programming software it had been using for years, because it could not calculate the code needed for the Yasda fast enough or with enough precision. “We needed a CAM software that was capable of optimizing the Yasda’s capabilities,” Finnie says, so he and his team began looking for new software that was up to the task.
They started with the list of possible CAM solutions provided by the machine tool OEM then conducted some online research to arm themselves with questions. Finally, after narrowing the field to two candidates, the team met with representatives of each of the solutions it was considering. Open Mind Technologies’ hyperMill software was one of those solutions.
“Much of our time together was spent in understanding their questions and showing concepts for five-axis machining ‘live’ in front of them so they could get an idea of the programming process, breadth of strategies, parameter settings and feedbacks available to a hyperMill user,” says Kevin Lewis, Open Mind account manager. “It is really about how the software works to help the programmer to complete the job quickly, how someone can minimize the number of iterations as a user moves from acceptable tool path to optimal, and how a safe and efficient motion can be delivered to the machine tool.”
Finnie says M.R. Mold chose hyperMill because it can make the Yasda YBM Vi40 “do what we want it to do: accurately cut difficult geometries in deep cavities.
“The combination of machine tool and hyperMill software allows us to more easily hold tight tolerances and deliver parts with superior surface finishes. If we want to take off one-tenth (0.0001 inch), we can remove one-tenth. That is exactly the type of accuracy
we need,” he says.
Nguyen says that the software’s dynamic (on-the-fly) collision checking during toolpath calculation and collision avoidance are key benefits in creating NC programs for the five-axis machine tool. “It automatically offers solutions before it moves on to the next section of tool path,” he says. “Our previous software would only check for collisions while in simulation mode after a tool path has been calculated. If a collision was then detected, we would then have to go back to either manually find a solution or change some parameters and recalculate, and then simulate again. As a result, hyperMill is much faster and more efficient to use.”
The learning curve in switching to a new software can be a challenge, especially when it occurs at the same time that a customer orders a very complex medical part. Although the job was one that M.R. Mold had completed in the past using its older equipment and process, “nobody here had ever operated a five-axis machine tool before,” Finnie says. “Suddenly we were faced with a machine that could rotate and tilt and move all axes simultaneously. On top of that, the programmers had to get up to speed on hyperMill so they could operate the Yasda and deliver the job on schedule.”
To help ease the learning curve, Open Mind delivered a training program on site that was entirely focused on M.R. Mold processes, upcoming projects and machine tools. Postprocessors for all the shop’s machine tools, including the Yasda, were delivered during training, and operators even ran the machines during class.
After the five-day training course, Nguyen programmed his first hyperMill five-axis job, machined it on the Yasda and completed it several days ahead of schedule. “We were able to eliminate most of the EDM operations, and as a result saved about two days’ worth of electrode manufacturing time,” Nguyen says. “With our old process, we also would have had to use multiple setups and several fixtures to tilt the cavity for the three-axis mills. On the Yasda, the whole job could be run completely unattended in one setup.”
Efficient and Accurate
M.R. Mold’s team recently finished machining a mold for a massage ball that is completely covered in spikes. Finnie says that if the shop had built that mold a year ago using its old process, it would have had no choice but to manufacture a whole series of electrodes for the project.
“I estimate that it would have taken us two days to design, program and manufacture the electrodes, plus another two days of vector EDM time on each half of that mold to produce all the undercuts on the cavities,” he says. “Instead, using hyperMill and the Yasda, our guys programmed and machined the entire mold in just one day, not six days as expected. So in my opinion, the machine tool and software are already paying for themselves.”
Finnie says the company now owns two seats of the software and, with the comprehensive training provided, two programmers are proficient with it. Additional programmers are expected to be trained in the future. Due to the success of the entire system, the company is also looking to invest in a System 3R robot and pallet changer for the Yasda sometime this summer.
LightFair 2016 HUGE success
M.R. Mold was invited to be part of the ShinEtsu booth at LightFair 2016. The partnership ShinEtsu put together included ShinEtsu, Arburg, M.R. Mold, and Graco.
The material produced a magnifying glass out of ShinEtsu's KE-2062 which ran in a 4 cavity mold by M.R. Mold & Engineering, mounted onto M.R. Molds' universal base featuring a 1 drop cold runner system. The entire process ran fully automatic on Arburg GmbH's electric Allrounder A 100 ton with an Integrated Arburg robot multillift 6kg, assisted by a Graco, Inc's F4-5 pumping unit which features increased precision and better color control..
The interest in OPTICALLY CLEAR SILICONE was evident at this event! What applications can you bring to the table with optical clear silicone?
M.R. Mold Exhibits its Technology at MD&M Minneapolis
M.R. Mold & Engineering will have molds running in
Engel's Booth 1125 - in mold slit duck bill
Arburg's Booth 925 - Optically clear silicone lens
Discount offered for Silicone Elastomers Course
- a comprehensive course on silicone elastomers -
JULY 25-28, 2016 AKRON, OHIO
Course Number: AP3276
Cost: $1,700.00 USD if registered by June 24, 2016.
Additional discount now offered: GROUP RATE: register 4 or more from one company and receive 10% off each attendee.
This 4 day course offers a comprehensive overview of silicone elastomers, including basic silicone chemistry, types of silicone elastomers, manufacturing processes, fabrication techniques, problem solving and application areas.
Presented by a panel of experts in the silicone field, this course is a MUST for entry-level and experienced rubber technologists, rubber chemists, process engineers, laboratory managers, supervisors, technicials, shop foremen, quality assurance managers and engineers, technical sales personnel and rubber producers and users. Everyone will find takeaways from this course.
Mel Toub, MT Consultants
Rick Finnie, M.R. Mold & Engineering
Craig Lustek, ShinEtsu Silicones
Stefan Scheibner, Arburg, GmbH
John Timmerman, Starlim North America
Bob Pelletier, Elmet
COULD THE DECLINE IN COLLEGE ENROLLMENT SIGNAL A TRADE SCHOOL RESURGENCE?
Manufacturing may benefit, as students spurn exorbitant college tuitions and dubious career paths.
By Clare Goldsberry in Injection Molding, Blow Molding, Business on April 11, 2016
Trade schools just might be on the cusp of a resurgence as college enrollment declines. A Bloomberg article on Oct. 4, 2015, “Decline of college degree seen in falling enrollment,” pointed out that college enrollment has fallen for three consecutive years after climbing for many decades.
The reason cited for this drop “is simple economics,” said Bloomberg. “College costs have risen dramatically, with much of the price tag going to pay for the salaries of administrators. At state schools, the rise in net costs—tuition minus financial aid—has been especially steep. But the actual out-of-pocket cost to students has been much higher than the rise in tuition.”
Additionally, “more people are questioning the benefits of college,” said Bloomberg. This is especially true among students “on the margin” for whom a college degree has a low value relative to the cost of tuition and being out of the labor market for an extended period of time.
That brings us to the manufacturing sector, which is hungering for employees skilled in various trades. While some politicians, such as Democratic presidential candidate Bernie Sanders, are promising “free college tuition” for everyone, it’s already evident that the “college for everyone” drive isn’t panning out so well. High costs and low job/salary opportunities are causing both parents and students to rethink their career choices. Let’s face it, college isn’t for everyone.
When I was working in the plastics industry, one of our moldmakers was an engineering student at Arizona State University, where I was also a part-time student. This moldmaker had taken some apprenticeship training and learned machining and then moldmaking while attending ASU. He made a very good living, upwards of $40,000 (in 1980s wages) at the mold company, which means that when he graduated he not only had a trade but an engineering degree, to boot!
We’re seeing more and more movement in the plastics/mold manufacturing industries toward apprenticeship programs; companies are feeling the pressure to attract and train the next generation of students. Trade schools are coming back in many areas of the country, and even high schools are starting to take notice. However, there are some caveats for these schools.
Keith Campbell, author of On The Edge
, an online blog, recently wrote about how schools ignore the law of supply and demand. “Why,” Campbell asks, “do we allow high schools and universities to ignore supply and demand when admitting students into educational programs and providing financial aid?” Campbell goes on to question why, when visiting “high school career and technology centers, you will find beauty shop classrooms overflowing with young women, machine shop classrooms nearly empty, and probably no classroom at all for industrial maintenance technology?”
Campbell aptly notes that high schools, colleges and technical/trade schools need to look at where the skilled jobs demand is greatest and implement programs that will best meet industry needs. While many graduates will have a difficult time finding work because they chose a career path where there is more supply than demand of employees, “manufacturing companies are crying for workers to fill the shortfall of two million skilled workers that are projected to be needed over the next 10 years for much higher paying jobs.” This same phenomenon applies to universities, which often graduate hundreds of students with degrees in areas of low demand, and very few in areas of high demand.
I would add that there are several reasons for this. While I’ve seen some very successful technical and skilled-trades programs in community colleges and trade schools, they are largely successful because they hire teachers who are closely linked to manufacturing. They also have tremendous support from the manufacturing community, including suppliers that provide the very expensive equipment the students need to get proper training and local manufacturing companies that offer internships and on-the-job training.
When Wittmann Battenfeld donated an EcoPower
injection molding machine work cell to the UMass Lowell Plastics Engineering center, students really benefited from that. For example, Mitchell Corneau of Providence, RI, has decided to pursue a master’s degree at UMass Lowell after he graduates with a B.S. in plastics engineering in May. His interest in plastics came from working in his uncle’s company, Plastixs in Charlton, MA, who encouraged him to look at the UMass Lowell program.
“It’s the only school in the country that offers post-graduate degrees in plastics engineering,” he said. “They run an extremely challenging program, but we know what we learn every day applies directly to the real world.” Mitchell recently returned from a three-month internship at GE Appliance Park in Louisville, KY, and has already learned how to operate the new Wittmann Battenfeld machine.
|Craig Cegielski (right) of Cardinal Manufacturing with state Representative Wayne Petryk.|
Eleva-Strum High School in Strum, WI, has a manufacturing program that goes above and beyond most high school or even community college and trade school programs. The Cardinal Manufacturing program was designed as a local way to address the skills gap in advanced manufacturing and to engage students in meaningful education by exposing them to the potential of manufacturing-related careers, said the school’s information. While it provides them with technical skills, the program also instills the “soft skills and professionalism” that employers want.
Taught by Craig Cegielski, who recently won the 2015-2016 Monsanto Fund Rural Teacher of the Year award given by the National Rural Education Association, Cardinal Manufacturing is a student-run manufacturing enterprise. It has real customers, real deadlines, real quality issues and ultimately earns real money through its welding, machining, woodworking, automotive and CAD classes. Students take classes in the ninth and 10th grades and then can apply for positions in Cardinal Manufacturing in the 11th and 12th grades. Profits from the enterprise are divided among the students at the end of the school year. Cardinal Manufacturing is supported by businesses, organizations and individuals.
While a four-year college or university offers many benefits to students, the price tag and difficult job market for many of the degrees offered are giving people pause. And it might also be giving people a reason to really explore where the jobs are, such as manufacturing, and look for schools that offer technical and mechanical skills leading to good-paying careers.
Campbell concludes that “we need to stop turning out students that have too-high expectations and too-little preparation for the real jobs and careers that are available. To those who say that kids don’t know what they want to do and college is a rite of passage, I say, work or the military will mature them faster than college, and they will figure out what they want to do. Then college, if necessary, to achieve their goals will deliver a real return on investment.” ( www.ontheedgeblog.com/article/do-our-schools-know-about-law-supply-and-d...
Reshoring Remained Strong in 2015
Reshoring Plus FDI Remained Strong in 2015
The number of companies bringing jobs back continues to increase
CHICAGO, Illinois, January 21, 2016 – The Reshoring Initiative®, an organization committed to helping manufacturers recognize the profit potential of local sourcing and production, has announced that “reshoring plus FDI remained strong in 2015” and surveys consistently show that the trend is increasing.
About 240,000 manufacturing jobs have been brought to the U.S. from offshore in the last six years, according to the Reshoring Initiative’s calculations. That job gain is the result of both new reshoring—the return of manufacturing work by U.S. companies—and Foreign Direct Investment (FDI) by foreign companies into our manufacturing sector. It also represents about 28% of the total increase in U.S. manufacturing jobs since the low of 11.45 million in February 2010. About 12.32 million Americans are now employed in the manufacturing sector. In fact, our research shows that more manufacturing work is now coming to the U.S. than leaving the country.
A strong reshoring trend in 2015
According to the Boston Consulting Group (BCG) Annual Survey released in December 2015, “the percentage of companies actively moving operations back to the U.S. continues to increase.” Of particular interest was the number of 2015 studies documenting the strength of the trend:
- BCG: Multinational industries actively reshoring increased 140% from 7% in 2012 to 17% in 2015 1
- Medical Design Technology: 49% of medical device companies outsourced offshore. Almost half of those, 45%, are returning 2
- Plastics News: 70% of plastics industry manufacturers have or will soon reshore 3
- Alix Partners: U.S. is favored over Mexico 55% to 31% 4
- Walmart continues to make good progress towards its $250 billion 10-year goal
- Reshoring Initiative’s preliminary statistics for 2015 show that reshoring and FDI resulted in around 66,000 U.S. manufacturing jobs. Final results will be released in early 2016.
“I spoke to AGMA and ABMA [Gear and Bearing Manufacturing Associations] in May 2015. In a poll of attendees, 54% had reshored or said that their customer had,” commented Harry Moser, founder and president of the Reshoring Initiative.
Tools for better supply chain sourcing decisions
The Reshoring Initiative offers many tools and resources to help companies make supply chain sourcing decisions. The Reshoring Initiative’s Total Cost of Ownership Estimator® is the best-known tool for this purpose. It uses advanced metrics that allow users to easily determine the total cost of offshoring by accounting for and understanding the relevant offshoring costs, which include inventory carrying costs, shipping expenses, intellectual property risks and more.
About the Reshoring Initiative
A 50-year manufacturing industry veteran and retired President of GF AgieCharmilles, Harry Moser founded the Reshoring Initiative to move lost jobs back to the U.S. For his efforts with the Reshoring Initiative, he was named to Industry Week magazine’s Manufacturing Hall of Fame in 2010. Additional information on the Reshoring Initiative is available at www.reshorenow.org. The Initiative’s many sponsoring associations and companies are also acknowledged on the site.
Sandy Montalbano, Reshoring Initiative
Engel Symposium, Corona, 2016
York/PA – December 2015
In support of the injection molding industry, ENGEL North America will be hosting Technology Symposium 2016 at their Technical Center in Corona/CA. The event, being held January 13, 2016, will feature information on the latest trends and technologies in machinery, processing, molds, materials and more.
ENGEL North America, member of the ENGEL Group, a world leader in the design and manufacture of injection molding machines and parts-handling automation, will host the complimentary Technology Symposium 2016 at their Technical Center in Corona, CA on Wednesday, January 13, 2016.
The morning portion of this single day event will consist of comprehensive technical presentations on the latest innovations in equipment, molds, materials, and decorative surface technologies. Presentations will be given by ENGEL specialists Markus Lettau, Joachim Kragl and Wolfgang Degwerth on trends including smart manufacturing, machine embedded intelligence, and Industry 4.0, including the potential of ENGEL inject 4.0 -- possibilities for networking, systematic data utilization and the use of intelligent assistance systems – and the many products, technologies and services ENGEL already has available to leverage it.
The event will also include presentations by several industry experts. Scott Larson, Founder and COO of Zomazz, will speak on the Digital Revolution of IMD, Sherman McGinnis, Sales Manager Injection Molds of Boucherie, will cover 21st Century Mold Concepts for Improved Quality & High Output, while Umar Latif, Technical Service Manager of Bluestar Silicones will discuss LSR Select: A Novel Technology for Optimizing LSR Molding. The presentations will be followed by an on-site networking luncheon.
The afternoon program will include a showcase of several ENGEL molding systems, demonstrating some of the most recent developments in equipment and technologies for injection molding, as well as a Partner Fair providing the opportunity to speak to the presenters to gather additional insight and information, network with peers, and talk to the experts.
The following systems will be showcased at the Symposium:
A smart manufacturing cell, including an ENGEL e-mac 310/105 US and ENGEL viper 12 linear robot, will be producing bursting discs for 1-ml safety syringes, with a shot weight of just 0.08 g per part, in a 16-cavity mold by Fostag Formenbau AG (www.fostag.com). The filigree polystyrene parts are designed with a predetermined breaking point that makes it impossible to re-use disposable syringes, which is an important safety feature. The very thin and different wall thicknesses require extremely precise process control. Too high a clamping force, or fluctuations in the melt volume, immediately leads to rejects. To prevent this, two software solutions from the iQ product family by ENGEL are used. One of them is iQ weight control, which automatically detects fluctuations in the melt volume and material viscosity and compensates for them in the same shot. The other is iQ clamp control, the new ENGEL software, which continuously adjusts the clamping force to match the current process parameters based on the mold breathing.
A second all-electric ENGEL e-mac 310/105 US machine – this one executed for liquid silicone molding -- will run a four cavity duck bill mold with in-mold slitting provided by M.R. Mold & Engineering Corp. (www.mrmold.com). The liquid silicone molding cell includes a dosing system by ELMET Elastomere Production and Service GmbH (www.elmet.com), with molding material supplied by Bluestar Silicones (www.bluestarsilicones.com). Demonstrating in-mold decorating, an ENGEL victory 330/85 spex US will be equipped with an ENGEL viper 6 robot and a single cavity mold with digital in-mold decoration from ZoMazz, Inc. (www.zomazz.com). ZoMazz’s digital in-mold decoration technology (D-IMD) provides infinite graphic variation, speed to market, and scalability at any production volume. The technology integrates seamlessly into existing IMD and IML injection-molding production lines, and allows graphic changes with a minimum of incremental cost or time.
Additional injection molding systems will also be running during the event.
ENGEL Fast Lane campaign
You’ve got the deal? We’ve got the machines. ENGEL staff will be available to discuss the special offer currently available on two of our top injection molding machine lines – the ENGEL e-mac and ENGEL victory – which are available for immediate delivery and with a reduced price tag.N
MOLDING 2016 - New Orleans - March 29-31, 2016
Molding 2016 is a unique event focusing on innovations in injection molding technology. At Molding 2016, industry leaders discuss the latest developments in various molding processes, equipment, materials and management techniques, with special emphasis on adding value to your business. These conferences are widely recognized as the most important forum for technical information and business conditions in injection molding.
Now in its 26th year, Molding 2016 brings global leaders and innovators in injection molding together under one roof in the world's premier technical conference on this technology. Come away with valuable tips and insights that you can't find anywhere else.
For more information, click here.
UWM Silicone Elastomer and Fabrication Course 2016
SCHOOL OF CONTINUING EDUCATION
EARLY BIRD DISCOUNT ENDS DECEMBER 2, 2015
DON'T MISS OUT ON THIS SPECIAL OFFER!
Silicone Elastomers Technology and Fabrication
This course offers a comprehensive overview of silicone elastomers, including basic silicone chemistry, mold manufacturing, information regarding pumping units and molding machines, manufacturing processes, fabrication techniques, problem solving and application areas. Emphasis is on liquid injection molding (LIM/LSR). This course is presented by a panel of experts in the silicone field, and time is allotted for discussion of specific project of interest
Featured at this course is a one day "field trip" to M.R. Mold & Engineering Corp. during which attendees will experience all the manufacturing processes involved in producing the actual LSR part.
WHO SHOULD ATTEND
Both entry level and experienced rubber technologiests, rubber chemists, process engineers, laboratory manager, supervisors, technicians, shop foremen, quality assurance manager and engineers, technical sales personnel, molding technicians and rubber producers and users.
- Silicone Elastomer Technology
- Liquid Silicone Rubber - Why silicone?
- Tooling Design and Construction
- Dispensing Systems
- Injection Equipment
- Molding Parameters
- FLow Analysis
Tues-Fri., Feb. 2-5, 2016
8 a.m. to 4:30 p.m.
Mel Toub, MT Consultants
John Timmerman, Starlim North America
Bob Pelletier, Fluid Automation, a Graco Co.
Rick Finnie, M.R. Mold & Engineering Corp.
Juergen Giesow, Arburg GmbH
Craig Lustek, ShinEtsu Silicones
Embassy Suites, Anaheim, CA
Call 714-938-1111 for hotel information or to reserve a discounted room (mention UWM)
EARLY BIRD SPECIAL
$1090 if enrolled by Dec 2, 2015
CEUs: 2.4 / PDHs: 24
PROGRAM NO. - 4830-8380
Don't miss this unique technology course.
Visit WWW.UWM.EDU/SCE-ENG today!
AMBA Plant Tour at M.R. Mold & Engineering
AMBA Plant Tour Workshop
M.R. Mold & Engineering, Brea, CA
February 12, 2016 8am - 12:30pm PST
$89 AMBA Members $189 Non-Members
Save the Date
With a steadfast commitment to over-the-top precision and tight tolerance levels beyond industry standards, M.R. Mold & Engineering Corp, Brea, CA, has built a stronghold in the medical silicone market. Specializing in the fields of liquid silicone rubber (LSR), gum stock silicone and plastic injection molds, M.R. Mold has positioned its operation as a strategic, global leader amongst a demanding, 'no-room-for-error' customer base.
The company's keen attention to detail is prevalent throughout the organization, from the tight-tolerance, flashless molds it manufactures to the personal, long-term relationships it cultivates with both its employees and its customers. By design, M.R. Mold has combined savvy marketing strategies and industry education to successfully brand the company's expertise in silicone worldwide. Through accuracy, innovation and a "customer first" philosophy, M.R. Mold is cutting a path to future global growth.
The LSR Learning Curve
Article From: MoldMaking Technology, Matthew Danford
, from MoldMaking Technology, Posted 11/1/2015
This increasingly popular thermoset material follows very different rules than any plastic.
A typical example of M.R. Mold’s work,this 32-cavity LSR mold for a consumer electronics part features a three-plate design and intricate cavity detail.
A part produced from the consumer electronics mold in the first picture.
M.R. Mold’s latest machine, the Yasda YBM vi40 from Methods Machine Tools, was chosen for more than the time savings that come with five-axis capability. LSR molds require the highest levels of precision, and this mold-and-die-industry hard milling system achieved 2.32-micron circularity in a tilted-cone machining test.
Here are just a few examples of LSR parts produced using M.R. Mold tooling: a baby bottle nipple...
...micro-molded medical parts...
...a cable clamp that consists of silicone molded over nylon.
Given the risk of flash, LSR tools like this valve lip seal mold employ side locks (the orange components visible here) for alignment rather than leader pins and bushings. Meanwhile, silicone vacuum seals (the blue strips, which M.R. Mold also sells in increments of 50 feet) ensure an airtight fit around the parting line.
LSR requires creativity when it comes to removing parts from the mold. This particular tool employs pop-up ejection.
At M.R. Mold & Engineering, orders for plastic injection tooling often inspire high fives on the shop floor. “I hope this doesn’t offend some of my friends in the industry, but we’ve found that plastic molds are just easier,” says Rick Finnie, company president. Although M.R. Mold churns out plenty of those, its true competitive edge is expertise in liquid silicone rubber (LSR), a free-flowing thermoset material.
This is an edge that’s proven particularly lucrative lately. Thanks largely to expanding use of this thermoset material, the pace of this Brea, California, company’s growth has been unprecedented during the past few years, Finnie says.
However, he emphasizes that market forces alone would never have been enough for the company to become one of the few go-to sources of LSR tooling on this continent. A specialized sector requires specialized knowledge, and gaining the ability to deal effectively with requirements foreign to thermoplastic tools took years of experimentation and a commitment to prioritize this work over all else. The case is the same for developing niche processing expertise that’s in high demand among molders and OEMs moving into this sector. In fact, M.R. Mold even markets its own auxiliary products, which run the gamut from material feed to part ejection (learn more in this companion article
Having come this far, Finnie and the rest of the company’s leadership are confident that M.R. Mold will maintain its reputation for LSR for as long as these applications are in demand. In the meantime, he says they’re more than happy to share their expertise with the broader industry.
Catching a Wave
M.R. Mold hasn’t always been known for LSR. Founded as a rubber compression and transfer moldmaker by Finnie and a single employee in 1985, the shop grew steadily until the industry experienced an exodus of work overseas around the turn of the century. With previous experience in building molds for this thermoset material, he and his team saw an opportunity to emphasize LSR work and carve out a niche.
The shop hasn’t looked back, and the time and effort required to truly master LSR has proven well worth it. Sales are expected to reach the $5 million mark for the first time ever this year, and LSR constitutes about 90 percent of that business, says Geralyn Anderson, marketing director. During the past few years, the 15,000-square-foot facility has added six new employees, bringing the grand total to 30, and added a slew of new equipment, including a high-end Yasda VMC, a laser engraver, a new injection press (the shop has five) and more. Nonetheless, backlogs reached unprecedented levels in 2014 and 2015.
This activity is being driven largely by OEMs finding new applications for LSR, Anderson says, particularly in the medical and consumer products industries. In addition to being fully biocompatible, the material tolerates harsh chemicals and extreme temperatures. That makes it useful for medical devices subjected to high heat during sterilization, or perhaps bakewear that can be stored in a freezer, Anderson points out. It’s also ideal for overmolding onto certain plastic, whether for instrument panel keypads or biocompatible (and comfortable) surgical instrument handles. Another advantage of LSR is flexibility. The material is not only strong, but also highly elastic. Additionally, its viscosity in liquid form is so low that it can fill cavities that are far too small for molten plastic.
A Different World
However, even the most experienced thermoplastic toolmaker or molder will find that certain strategies just don’t translate to LSR, which is processed very differently, Finnie says. For one, there are no hardened pellets in these applications. Rather, the material ships as two separate compounds, both with a thick, paste-like consistency. Blending these compounds in a mixing/metering system (whether a press-mounted unit or an auxiliary device) creates a chemical reaction that, along with heat, drives the material to cure into a solid. Keeping it in the liquid state for molding is accomplished via a water-cooled injection barrel and/or runner system, and the mold itself is zone-heated to temperatures ranging from 300°F to 400°F.
Suffice it to say that a different process for a different material requires different thinking, from the design of the tool all the way through part ejection from the press. Here are a few examples that Finnie cites as most significant:• Cold manifolds.
As is the case with thermoplastic applications, many LSR molds feature runnerless construction—that is, one that delivers material via a dedicated manifold that leaves no runners or sprues to eject with the part. The difference is that LSR manifolds feature water-cooled channels rather than the heaters employed by plastic injection mold hot runners.
The advantages are similar for both types of tooling. Namely, cycles are faster because there is less material to process, and having no runners to remove facilitates demolding automation. However, these advantages are more pronounced with LSR, Finnie says. One reason is that curing LSR tends to take longer than cooling plastic, Finnie says. That translates to greater cycle time improvements, particularly for small parts that that might weigh less than a traditional runner. What’s more, LSR can’t be reused once cured, and the material tends to be more expensive than plastic resins.• Closer fits.
Regardless of whether the design calls for a cold deck, the toolmaker has to contend with the fact that LSR flows like water in its heated, liquid state. In fact, its viscosity is so low that it will flash into gaps as small as 0.0002 inch, Finnie says. That means plates must be parallel and flat, fits and clearances are critical, and only the highest levels of precision will do. “I’ve had some knowledgeable people in this industry say they won’t accept a drawing with less than five thousandths flash extension,” Finnie says.• Vacuum sealing.
Such tight fits don’t leave much room for venting air and any residual gasses from the cavity prior to material injection. Adding to this challenge is the fact that LSR undergoes a gas-creating chemical reaction when the two constituent components are mixed. Thus, these applications typically require vacuum pumps to help clear cavities of all gasses immediately prior to injection. Proper application of a vacuum pump also requires an air-tight seal around the entire parting line, typically in the form of fitted silicone strips.• Tighter gating.
LSR’s low viscosity has implications beyond fits and clearances. “Large gates are one of the biggest giveaways that a silicone mold was made by a plastic shop,” Finnie says, noting that a typical LSR gate might measure only 0.003-inch deep. Smaller gates lead to other considerations as well. For instance, smaller runners should be fully round if possible to avoid breakage, and standard plastic-injection sprue bushings are usually far too large to achieve efficient cycle time in an LSR application.• Tighter venting.
What’s more, the use of a vacuum pump doesn’t preclude the need for dedicated vents. Given the risk of flash, those vents are typically far smaller—and more demanding to machine—compared to their plastic industry counterparts. Most measure 0.0001 or 0.002 inch deep, whereas plastic mold vents don’t trend much smaller than 0.0005 inch or so, Finnie says. At M.R. Mold, vents might be milled, ground, burned or even laser-machined within depth tolerances measured in the millionths of an inch.
Similarly to many plastic toolmakers, M.R. Mold employs Sigmasoft virtual molding software from Sigma Plastic Services to ensure vents are located at the last place in the cavity where material will reach. However, this tactic is particularly critical for LSR molds, because the need for tight fits between components in these tools presents fewer options for venting. For instance, straight-walled ejector pin holes can’t double as vents in LSR tooling, because the material would flash into the gap surrounding the pin. Only a tapered shutoff will do. • Fewer moving parts.
Ejector pins aren’t the only common mold component missing from most LSR tools. These molds don’t usually incorporate slides, lifters or other moving actions either. That’s because undercuts simply aren’t as much of a concern. As an example, Finnie cites a protective face mask that can literally be peeled off the core without risk of damage—the material will simply stretch and snap back into place.• Challenging ejection scenarios.
Although the material’s high elasticity can simplify mold designs, LSR presents its own challenges for part ejection. With plastic, the right mold design can ensure the material will essentially wrap itself onto a specific portion of the geometry as it cools and shrinks. However, that’s not the case with LSR, which expands as it cures. “We have to go to extra lengths to ensure that parts will be where we want them to be when the mold opens,” Finnie says.
Consider the baby bottle nipple pictured in the gallery on the right side of this page. The large flange at the bottom prevents the nipple from falling into the bottle. However, it’s also molded with an undercut that tends to keep the whole part stuck in the cavity. To keep the part on the core side for effective de-molding at the customer’s plant, the tool incorporates a second undercut to mold the rib visible just above the bottom flange. Actual ejection is accomplished via a stripper plate and a core-side air blower.
Partner and Ambassador
Factors like those outlined here make LSR different enough and challenging enough that Finnie recommends sourcing molds only from manufacturers that specialize in this tooling. Granted, deep collaboration between toolmakers and molders is important throughout the industry. However, it’s often even more critical for a material that is gaining in popularity even as it remains foreign to many.
This is why, for M.R. Mold, expertise is perhaps the most valuable currency. It’s also a currency the shop is willing to spend freely, even beyond direct dealings with customers. Claiming that M.R. Mold is one of a handful of North American shops that can do this tooling well, Anderson says Finnie and the rest of the leadership take the company’s role as LSR ambassador quite seriously. Seriously enough that Finnie is an instructor in a silicone elastomers class at both Penn State University and the University of Wisconsin–Milwaukee. Although processors are the primary target, Anderson says all are encouraged to attend. “We’d rather have competitors doing it well than have a bunch of frustrated people out there who don’t understand it,” she says. “If we’re going to keep manufacturing in the U.S., the industry needs to be educated.”
A Mold Shop OEM
Article From: MoldMaking Technology, Matthew Danford
, from MoldMaking Technology
Posted on: 11/2/2015
Years of helping customers save time and money in liquid silicone rubber (LSR)—a material that involves very different considerations from plastics—has led this shop to develop its own product line.
M.R. Mold’s cold runner systems are available in standard and built-to-order patterns for single, 2-, 4-, 8-, and 16-drop configurations with various options. The standard cold runner system is 9 7/8 wide by 11 7/8 long, and the nozzles are 3.5 center to center in distance.
Designed primarily for prototyping and short-run production, the stuffer box enables quick cleaning and material changes.
The company says its vacuum seals (the blue sealing strips visible on this tool) feature a tapered body that prevents pinching by the parting line and the compression set seen when using typical O-rings.
As detailed in this feature article
, molding liquid silicone rubber (LSR) requires a completely different mindset from molding plastic. The same goes for manufacturing the tooling. Different enough, in fact, that a shop focused mostly on this niche day-in and day-out is more likely to develop its own innovative methods of saving time and money for customers.
So says Rick Finnie, president of M.R. Mold & Engineering, a Brea, California-based shop that thrives on decades of experience in LSR. Over the years, the shop has parlayed many time- and cost-saving strategies into its own line of specialty equipment, some of which it even sells to competitors. The line includes the following:*Pneumatic Stuffer Box.
Changing to different LSR grades in prototyping, short-run and micro-molding applications typically requires breaking down and cleaning the pumping unit on the press, a time-consuming task when seconds count. As an alternative, the shop offers pneumatic stuffer boxes in various sizes and pressure ratings. Customers mold one material, detach the stuffer, place it in the fridge for the next use, and move on to the next material. This can significantly reduce changeover times, Finnie says, and the stuffer box’s single cylinder is easier to clean.*Universal Base.
Also designed with changeovers in mind, this system keeps costs low by enabling customers to swap out interchangeable inserts instead of the entire tool.
M.R. Mold manufactures and markets its own tapered, hollow-body silicone parting-line seals in increments of 50 feet.
*Cold runner system.
From the very outset of M.R. Mold’s journey into LSR, off-the-shelf cold runner manifolds have been more difficult to find than hot runners, and customers often complained about them anyway, Finnie says. So, the company developed its own cold deck. Available in open-nozzle as well as valve-gated configurations, this system is a portable, self-contained assembly that can be re-used for multiple jobs.
Given the challenges of de-molding LSR and the fact that every job is different, designing and building end-of-arm tooling has long been commonplace at M.R. Mold. Knock-out pins, various types of mold sweeps, various types of grippers—all are common here, Finnie says. Deciding on the best solution for the job is typically a lengthy process involving significant trial-and-error and back-and-forth with the customer.*Custom integral robot.
Years of working on creative ejection solutions led M.R. Mold to recognize an opportunity to develop its own robot, one designed specifically to be customized for LSR applications. Described by Finnie as a "relatively simple" system, the single-axis robot can incorporate a wide range of the aforementioned end-of-arm tooling. Mounting to the top of the mold or to the press, it is available in both hydraulic and pneumatic configurations and in both sweep and grip/push/release styles.