Posted by Mario Del Real on Thu, May 10, 2012
Plastics companies are developing some very unique injection-molding resins that conduct electricity. These manufacturers often utilize nanotechnology to produce tiny metal fibers and strands that are incorporated into the matrix of the polymer. Both the metal’s conductive and physical properties impact the performance of the composite material, so the function of the product or part must be perfectly understood at the beginning of the project.
A wide variety of resins can be “doped” with conductive metal—the most popular resins are polycarbonate (PC), polypropylene, ABS, polyamide 6/6, and PC/ABS. Conductive fillers are typically stainless steel fiber and nickel-plated carbon fiber. Nickel is conductive, magnetic, and corrosion resistant. All these composite materials can be injection-molded (including complex shapes), producing parts that are as hard and durable and conductive as the metallic parts they replace—as well as lighter in weight.
Resins are doped with a specific concentration of micro-sized or nano-sized metallic materials and then pelletized. These particles are then homogenized throughout the material during injection molding. The shape of the metallic particles are also important—they can range from nickel-coated fibers that act as major conductors and ground planes to three-dimensional branched or looped nanostrands that also provide specific mechanical properties and electromagnetic shielding.
Applications for conductive composites abound, including electronics, lighting circuitry, medical devices, cable connectors, antennas, shielding, switch actuators, and thermal equipment.
ElectriPlast Corporation in Bellingham, Washington makes electrically conductive hybrid plastics for industrial, commercial and consumer products and services. Its core product line, ElectriPlast™, is a family of non-corrosive, electrically-conductive resin-based materials whose properties allow it to be molded into multiple shapes and sizes associated with plastics and rubbers—but which is as electrically conductive as if it were metal. By replacing traditional metal parts component weight may be reduced by 40 to 70 percent.
In February the company announced an agreement with Korean firm Hanwha L&C, a global supplier of interior and exterior automotive components made from lightweight materials such as glass fiber mat-reinforced thermoplastic, lightweight reinforced thermoplastic (LWRT), and expandable polypropylene (EPP).
Hanwha L&C conducted extensive independent testing of conductivity, shielding (both electric and electro-magnetic), and mechanical strength; the results met or exceeded all the company’s requirements.
“We see the conductive plastics market as a tremendous growth opportunity and the ElectriPlast technology as a leader in this young industry” says Won S. Choe, Hanwha L&C’s vice president of business development. “We have many potential uses for ElectriPlast in our different lines of business, including our automotive division.”
Posted by Al Elger on Wed, May 09, 2012
Because of more stringent federal fuel-efficiency expectations, the automotive industry has been looking for ways to reduce the weight of cars to reduce fuel consumption. One of the solutions is proving to be plastic composites that are just as strong as the metal they replace—and significantly lighter. Both thermoplastic and thermosetting composites are being engineered to replace steel and aluminum without compromising performance. Making these parts from plastic composites can also increase innovation in the design phase, giving manufacturers more opportunities to reduce overall production costs.
Reinforcing plastics with short glass fibers improves strength, stiffness, and heat deflection temperatures. Glass fiber-reinforced thermoplastics and polypropylenes are being used more in the automotive industry to replace metal parts (as well as plastic parts that don’t last as long as glass-reinforced plastics). Glass-reinforced polyamide and polyphthalamide are becoming popular replacements for metal in cylinder heads and other engine cooling components in vehicles. Glass-fiber content can be 50 percent or more, creating a very high modulus. These short glass-reinforced plastics can be ideal materials for parts and products in other industries where superior strength, heat-resistance, and lighter weight are required.
There are also long fiber-reinforced thermoplastics and polypropylene (LGFPP)—although these are more expensive, they are higher performance, especially in high-temperature applications. Because of its strength, LGFPP is an ideal material for manufacturing parts with thinner walls—which also reduces weight and material costs. LGFPP also has a lower specific gravity than other resins such as PA or PC/ABS, another cost reducer.
Carbon fiber-reinforced plastic (CFRP) is another family of lightweight materials that provide superior strength and has high interest among automobile manufacturers, especially for larger body parts such as side panels, which could reduce the weight of a car by 50 percent or more.
To further this research, Ford Motor Company has partnered with Dow Chemical Company to investigate ways to bring carbon fiber into high-volume auto production—with the goal of reducing the average car’s weight by 750 pounds. Key research considerations include material cost, faster processing of carbon fiber molding, and discovering new ways to join composites to metal. Carbon fiber is already in production in limited volumes for specialty cars, most notably Germany’s BMW, but the process is slow and expensive.
Not to be outdone, General Motors Company just signed a deal with Japanese firm Teijin Ltd. to build a $7.9-million composites development center in the Detroit suburb of Auburn Hills. The center will develop large-volume carbon fiber production for the auto industry using a proprietary process that can mold carbon fiber reinforced thermoplastic within cycle times of one minute.
Posted by Al Elger on Wed, Apr 11, 2012
There are lots of industries that can take advantage of antimicrobial resins—a few examples are clean rooms for sensitive electronics testing and assembly, water-treatment systems, food packaging, plumbing and HVAC, sterile packaging, conveyors, public transportation, medical/diagnostic equipment, dental implants, personal care products—even office equipment.
You may want to consider antimicrobial resins for your injection-molded product if surface bacterial growth is a problem and inhibits performance. Aesthetics matter, too—bacterial discoloration or bioslime can be huge turn-offs, depending on the use of the product. Chances are if the production environment has moisture, heat, and organic material, bacteria will be lurking there too, which could be problematic for operations.
The good news is that bacteria can be eliminated from these surfaces if they are manufactured from antimicrobial resins. These are different from the antimicrobial coatings that are sprayed onto products such as hip implants—this is popular in the medical field but the coatings are subject to erosion by joint action and abrade over time.
New advanced polymers are being made with an antimicrobial agent embedded in the resin itself, so the exposed surface is always a deadly place for bacteria. The antimicrobial compound is added during the manufacture of the resin and does not alter the physical or thermal properties of the resin—which still remains highly suitable for injection molding.
There is quite a variety of antimicrobial agents to choose from, depending on product use and the polymer family selected. Ionic silver is one of the most popular and is highly effective as a broad-spectrum antimicrobial agent in medical and dental applications. Silver is known to kill over 99.99% of bacteria within 24 hours of contact and remains effective over the lifetime of the product—the silver ions short-circuit the bacteria’s ability to reproduce and they die quickly; better yet, silver does not harm human tissue. Antimicrobial resins have been developed than can kill the most deadly infections, including MRSA, an especially resistant and potentially deadly bacterial infection often found in hospitals.
Antimicrobial resins can be formulated for all standard injection-molding materials, including standard polymers, engineered polymers, and thermoset materials. Part of the challenge in engineering antimicrobial resins is finding the right “carrier” for the antimicrobial agent that integrates homogenously into the resin without altering its physical or thermal properties; chemical concentrations must also be carefully calculated to provide a steady release of ions at a pre-determined rate.
If you are interested in learning more about antimicrobial resins, contact Kaysun and we’ll help answer your questions, connect you with qualified suppliers, and of course work closely with you on your project if you take it to development.
Posted by Al Elger on Fri, Apr 06, 2012
Snap-fit designs can be an effective way to replace fasteners/hardware in injection-molded parts or products. There is growing interest by manufacturers in snap-fit because it can save time and money. Snap-fit connections are just as strong as fastened connections and can replace nuts, screws, washers, etc. No other adhesives, solvents, or fastening processes are needed. Snap-fit is designed right into the molding process, eliminating assembly steps and speeding up assembly and throughput. It also reduces material needs, saves on material costs, and makes the product lighter weight. An added benefit is environmental—because snap-fitted products are easy to take apart it’s easier to separate and recycle different materials.
For most applications, snap-fit connections are the simplest and most cost-effective way to assemble two parts—making them ideal for high-volume production because it is a quick and easy step to complete. This reduces the risk of improper assembly, which occurs more frequently during a step that requires more components (fasteners) and tools.
Which snap-fit is best for your product depends on the intended use and the material/design strength that is required to keep the snap-fit secure. Snap-fits can be engineered to be a permanent connection or allow frequent assembly and disassembly (like battery compartment covers in electronic products). Gas-tight and fluid-tight snap-fit connections can even be made when snap-fits are engineered to work with seals and O-rings.
Even though snap-fits are relatively simple in design and how they operate, incorporating them into product design does add complexity and cost to the molding process. This is because engineers have to consider the functional requirements of the connection and the product, assembly requirements, mechanical properties of the thermoplastic (strength, flexibility, recovery), and changes to the design of the mold (including part ejection). The design must ensure that the snap-fit has the proper “holding power” to keep the connection secure without bending too much, or breaking. These calculations become more complex, too, if the snap-fit application requires hundreds of openings and closings. Since most snap-fits require an undercut, a mold with side action is often needed.
Depending on the design and intended use of the product, snap-fit connections can increase the cost of molding and tooling. However, once the snap-fits are designed and production is underway, the extra cost of the molding process is usually quickly recovered by lower assembly costs, faster throughput, and less rework.
Posted by Mario Del Real on Fri, Apr 06, 2012
One of our favorite conferences is BIOMEDevice—a wonderful opportunity to learn the latest in medical device development and meet a diverse group of industry professionals throughout the medical device supply chain, including designers, engineers, and regulatory and marketing/business development executives.
Conference details can be found at http://www.canontradeshows.com/expo/bioboston12/.
Admission is free for qualified registrants (otherwise it is $45 for the two-day event). The conference is one of the best opportunities in 2012 to talk one-on-one with some of the top medical device manufacturers and suppliers/vendors in the country, getting key insights and advice from leading experts in every part of the supply chain
Presentations include:
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Design and Development of a Medical Device: From Concept to Production
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Integrating Risk Management with Product Design
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IP Strategy under Patent Reform for Medical Device Design and Development
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Speed to Market for Medical Devices
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Human Factors in Medical Device Design
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Meeting the Demands of the “Next Generation” Patient: User-Centric Design and Development
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From R&D to Innovative Medical Device: The Role of Product Development Policy
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Mobile Medical Devices: A Risk-Based Approach
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Design and Development of a Medical Device: Manufacture, Compliance, Innovation
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Developing Medical Devices for Manufacturability
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Polymeric Medical Device Design: Materials Selection and Characterization
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The Roadmap for Materials: Upgraded Functionality and Flexibility
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Supply Chain Collaboration to Better Improve Cost Efficiencies
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Supplier Controls: Partnerships in Design through Transfer into Manufacturing
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Ensuring Proper Use of Low-Cost Bench Testing to Optimize Medical Device Field Results
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Software Verification and Validation: Implementing Critical Updates to IEC 60601
Quite the line-up!
If you already manufacture a medical device and want to know how to make it better and lower cost, or you are looking for a medical device manufacturer or key supply-chain partners who can help you with the entire process, from concept to production, this is the place to be. Kaysun Corporation will be there—be sure to stop by Booth 1014 and say hello. Hope to see you in Boston.
Posted by Mario Del Real on Tue, Mar 13, 2012
Moving an idea from conception through production can take many paths. Paradoxically, what may appear to be the simpler path can lead to more complications, and vice versa. That is, more time and effort spent up front can simplify the process and provide efficiencies that may have otherwise been overlooked and lost.
When speaking with manufacturers, we see a wide range of openness to seeking or accepting outside assistance from a plastic injection molding supplier. The attitude may be, “Why should we pay an outside vendor when we have our own staff engineers?” At the other end of the spectrum, a customer may acknowledge, “We want our molder to take our idea and use its expertise to design the best, most efficient process to bring it to fruition.” And, of course, there is a whole range of perspectives in between.
Basically it comes down to early engagement with the right vendor. The sooner a customer explores the options, the better a qualified vendor can begin to offer the requisite engineering support to a project. This support may range from our team working with a customer’s in-house staff to Kaysun totally managing the process. And, again, there may be a whole range of working structures in between, whichever is optimal for the project.
In the case of high-end plastic injection molding, engineering support may consist of tool design that combines up-front features that can reduce the number of parts needed and minimize retooling. For example, insert molding or overmolding; selecting the materials and additives that will provide the optimum balance of performance and cost-efficiency; performing finite element analysis (FEA) to ensure the functional requirements of the part are met; designing the tool and the part so that they work hand in hand; the list goes on.
Since all these considerations are interdependent, a vendor’s ability to look at them all allows a “big-picture” view that facilitates an optimum solution. If you need a vendor that has the ability to take into account all aspects of a project, Kaysun’s engineering team is ready and able to help. Or, if you’re not sure of what you all need to take into account, we can help you define these considerations as well.
Posted by Bobby Desai on Tue, Feb 21, 2012
Occasionally clients want to know about new materials that have specific properties which may be better-suited for different or expanded applications of the products they make—properties such as heat or chemical resistance, hardness, flexibility, friction coefficient, clarity, biocompatibility, etc.
Plastics manufacturers and suppliers continue to announce new grades/blends of resins, often with expanded capabilities that give product designers more freedom in developing next-generation products. Injection molders like Kaysun Corp. who stay in touch with manufacturers and distributors about material advances can keep clients up to date on new compounds that could benefit their product lines, or even boost market share.
For example, RTP Company, a custom-engineered thermoplastics provider, recently announced its line of polylactic acid (PLA) bioplastic compounds has expanded to include impact-modified grades (injection and extrusion) suitable for more durable applications. These new materials are also more heat-resistant, making them competitive with traditional thermoplastics. Even better, PLA resins are derived from renewable resources—not petroleum. Manufacturing PLA biopolymers also uses less energy and produces less CO2 than petroleum-based thermoplastics, making them a sustainable alternative to thermoplastics such as polyesters and high-impact polystyrene.
Many manufacturers would love to get their hands on materials that have all the key performance characteristics they are looking for but weigh less. BASF just established a multi-material lightweight composites team to develop new materials for the automotive industry. Lighter weights can be achieved by incorporating multilayer fiber structures into the molded plastic. Called "resin transfer molding" (RTM), this process can produce large and complex composite components in a single operation. Future discoveries will likely have a wide range of applications across other manufacturing industries, wherever weight can be reduced and performance enhanced by replacing metal with lightweight yet strong composite materials.
Another Kaysun partner—DuPont—has recently developed a new grade of low-friction, low-wear acetal resin that extends the range of special control and premium-control grades. This type of high-performance polymer is typically used for medical devices. The new resin is the material for the dose dial sleeve in self-injection systems that deliver insulin or other drugs from a pre-filled glass cartridge. The patient uses the sleeve to set the required dose. Reducing the friction between the sleeve and the cartridge makes it easier to set the dose and inject the drug. The low-wear and low-friction properties of the new resin also make the delivery mechanism last longer.
Posted by Mario Del Real on Mon, Feb 20, 2012
Sealing is one of the most important steps in the production process—especially if the product’s performance could be compromised by atmospheric elements or particulate matter like dust. This is particularly true for sensitive electronics with medical, defense, and industrial applications. Water, humidity, dust, and other liquids can penetrate into these devices and result in malfunction or failure if they aren’t sealed properly.
The number-one factor in having strong seals that work flawlessly is that the plastic parts must be designed and molded correctly, with the seals in mind. This is a step that is sometimes overlooked by manufacturing companies. If there is too much variability in tolerances, the following problems may result:
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Parts aren’t flat enough to seal cleanly with a gasket-type seal
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Parts have excessive parting lines on the sealing surfaces that create leak paths
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Parts don’t meet dimensional requirements consistently enough to form a seal
The keys to obtaining a good seal are 1) forward-thinking design, and 2) consistency in the part manufacturing. Not only does a good seal have to be planned into the design process, the mating components must be manufactured with consistent precision.
The conditions of use for the part or product must also be considered when evaluating seal possibilities. For example, with fuel and coolant applications, material compatibility is a top concern because the physical characteristics of certain materials change in the presence of fuel and coolant, creating leakage issues.
Submersible applications are the biggest sealing challenges; this is where having high-precision molded parts is extremely critical. Creating strong seals that keep fluids out when the product is immersed is much more difficult to do when the system/parts are exposed to pressures that are constantly acting to break the seal. Any small imperfection in the part may escape detection during in-process leak testing but fail in the field after enough time has passed, so precision parts are a must.
Sealing is a key part of the manufacturing process and needs to be approached uniquely for each product to make sure that design and material issues are not overlooked. The first step is making sure the materials and design are validated with the seal and mating parts in mind; the next step is using a robust, highly controlled molding/manufacturing process to produce high-precision parts that will allow full, appropriate function of the seal. Companies need to ask about sealing when they are looking for an injection molding partner to produce a part that requires high-performance seals, especially for mission-critical applications.
Kaysun Corporation's engineers are available to assess the ever-changing needs and select the proper resins and production methods to meet this demand. Please contact us to assess and scope your next project. Contact Us Today.
Posted by Mario Del Real on Fri, Feb 17, 2012
There are lots of good reasons for changing from metal to plastic components—the big three are cost reduction, lighter weight, and zero corrosion.
Yet it seems a fair number of companies that have tried the switch eventually go back to metal, citing two major problems: 1) inconsistent processing and 2) inconsistent dimensions.
When parts are converted from metal to plastic there is typically not much relaxing on the tolerances—that means the processing of the parts has to be done very consistently. That can be a challenge for vendors. Consistency is impacted by a number of factors that have to be carefully monitored, such as melt flow index of material, dryness of material, machine processing parameters, maintenance of the machines, and most importantly, being able to see what is happening inside of the mold as the parts are being molded with the use of pressure transducers (sensors) also known as Scientific Molding.
Without the ability to properly monitor these factors there will be ongoing quality issues with the processing, parts, and tolerances; it also makes the root cause for any failures very difficult to determine. That’s why it is ultra-important to have the appropriate monitors in place and run a robust quality system to oversee the process.
When vendors cannot meet tolerances consistently with plastic parts, this creates additional costs in reworking parts (machining), quality costs to sort or even re-call parts from the field, and possibly even lawsuits for failures in the field.
It only takes one bad experience with plastic parts to drive a company back to metal. For a successful metal-to-plastic conversion, select an experienced vendor. Proper internal controls on machines and quality systems are essential. Tool construction/quality also plays a bigger role than many people realize—there will always be less rework to get the dimensions within spec with high-quality tools (and the tools will last longer).
When metal to plastic is done correctly, there are some big advantages:
Lower cost to produce
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No secondary process to prevent oxidation
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May be able to eliminate some assembly
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Plastic is generally less expensive than metal
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May be able to eliminate costly machining operations
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Lighter weight means lower shipping charges
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No painting needed, molded in color/graphics
Lighter weight
The key to a successful metal-to-plastics conversion is understanding the limitations of the process, materials, and tools before committing to a project. At Kaysun we will evaluate a project in detail and determine if it is a good candidate for conversion based on several key factors, including required tolerances, materials, specific part design/configuration, and initial mold flow/analysis. Contact a Kaysun engineer now to see if your program would benefit from a metal-to-plastics conversion.
Posted by Al Elger on Fri, Feb 17, 2012
Many of the customers with whom I have been meeting with are increasingly looking to consolidate vendors while designing their products and engineering the production processes for the desired result. Reasons for this make good business sense, and include reduced development time and associated costs, improved logistics, and a single point of contact.
The issue is, in the case of custom plastic injection molding, is it may be difficult to find a supplier that is able to provide a solution that requires multiple molding expertise and capabilities in order to optimize the process.
Most plastic injection molding companies concentrate on one or two technologies and processes, such as traditional molding, scientific molding (both decoupled II and III), two-shot molding, overmolding, insert molding, or soft-touch molding. All of these processes have similarities, but each is unique in its own way and requires different equipment and knowledge. More importantly, the expertise to help determine which method(s) is/are optimal for the desired end product is a crucial value-added element in the development process.
Some molders may specialize in one of the aforementioned processes and do it very well. Others may offer one or two. From my discussions with customers and research into the market, however, I think it is rare that a vendor has the capability to effectively execute all of these processes, and the knowledge to determine the optimal production method.
Kaysun’s ability to provide solutions across all of these production processes and realize for the customer the benefits of consolidating a supply base for plastic injection molding has been a real asset. As always, the earlier a customer engages with the right supplier the more cost-efficient and timely the process will be.