Guill Tool & Engineering’s President Glen Guillemette explains how tooling maintenance improves efficiency, enhances quality, and boosts overall productivity for medical tubing.
State-of-the-art production equipment and processes hold extremely close machining tolerances when producing multi-lumen and multi-layer medical tubing. However, tool misalignment or maintenance issues can produce exaggerated impacts on the final product.
Improperly maintained equipment can waste 10% to 20% of the material, which can run from 50% to 90% of product cost, since in extrusion processes materials costs are typically higher than labor costs. Tooling suppliers go to great lengths to maintain tips and dies to a determined specification, ensuring perfect concentricity and alignment. Proper maintenance keeps it that way.
Clean parts, especially with sealing and locating surfaces, are key to product performance. These surfaces receive the most care and attention during manufacturing and are the control surfaces that ensure uniformity throughout the tubing. A speck of dirt the size of a human hair – about 0.003" (0.08mm) – can impact precision-machined alignments, so cleanliness is critical to all surfaces. Double- and triple-layer extrusion heads pose even greater maintenance challenges since the number of sealing, centering surfaces multiplies and can magnify dirty tool problems.
Foreign matter usually enters equipment during changeovers when operators disassembled the head to change compounds and/or tips and dies. Thoroughly remove residual material and check for tool deformities, such as burrs, scratches, and scrapes – usually a result of careless handling and/or equipment storage.
Guill Tool & Engineering Co. Inc. has supplied quality extrusion tooling since 1962. First established as a freestanding support facility for the wire and cable industry, the company has expanded its product line to include fixed or adjustable center crosshead and inline tubing dies for the demanding medical, electronics, defense, and aerospace markets. All crossheads and inline dies are available for multi-layer applications.
Using dedicated work carts designed for extruder head maintenance can produce the best return on investment from well-maintained tools. In addition, make sure proper lifting aids are available. Get help for heavy parts, as surfaces and edges are hard and brittle, so dropping a part or striking them together can cause damage. After thorough cleaning, properly store tools in a dedicated, clean, and dry area with soft surfaces where each instrument is covered and separated. For tool disassembly, use purpose-built tooling – tool costs are easily offset by avoiding damage frequently caused by improper equipment. Follow operator’s manual guidelines as individual tools may have specific recommendations.
Equipment should be cleaned while still hot, since residual polymer and rubber is easier to remove. Be sure to follow all Material Safety Data Sheet (MSDS) recommendations when heating the tooling. Thermal gloves can protect hands from heated tooling surfaces. A brass scraper and brass or copper wool cleaning cloths are recommended because they are soft enough to avoid scratching the surface.
The quickest way to remove the die is to employ the pressure of the extruder to push it out. Clean the body and body feed port with compressed air and brass pliers to simultaneously cool and remove excess residue from feed ports. Follow this by using a round brass brush to polish the surface and clean the flow area of the flange adapter.
Most manufacturers recommend a hand polishing stone to remove offending burrs. Follow stoning by lightly applying a 600-grit emery cloth if necessary, avoiding sharp, rounding edges.
With an improperly centered tool, a calculated out-of-tolerance area of 0.05in2 (38mm2) was derived. When comparing the two surfaces, the material waste was 11.8% of the finished product.
Alternatively, if the percentage wall can be increased from 80% to 95%, this will save about 12% total costs.
Flat sealing surfaces can also be cleaned with a stone, followed by a 600-grit emery cloth. Place the cloth on a clean, flat surface, preferably a surface plate, then apply friction in a circular hand motion until the area is clean and even.
Hardened steel alloy parts will not be adversely affected using these methods.
Working from a dedicated tool cart, give each component a final wipe down with a clean rag. Reapply anti-seize compound to fasteners if required. Tighten fasteners to manufacturer’s recommended specifications in the sequence specified in the manual – typically a star pattern. Gradually tighten until reaching proper torque.
One goal of a die manufacturer is to form a concentric cone as quickly and accurately as possible in the primary section of the die – when the extrudate first emerges from the die’s distribution capillaries. A properly designed and manufactured die has even distribution close to the extrudate entrance point. A properly manufactured and aligned extruded head, along with well-maintained tooling, will require little or no adjustment.
However, unnecessary die adjustment can negate this accuracy. Unnecessary die adjustment can also create unbalanced flow that stresses the extrudate. The final product retains memory of this imbalance, leading to unpredictable die swell.
Tooling maintenance ensures a quality extruded product – one that meets dimensional specifications, maintains the specified minimum tolerance, and is produced economically. Dirty, neglected, and improperly adjusted tools contribute to excessive compound applications, which can complicate maintenance of minimum thickness tolerance. Excess material creates unnecessary costs, directly affecting profitability and relationships with customers.
About the author: Glen Guillemette is president of Guill Tool & Engineering. He can be reached at sales@guill.com.
Medical equipment manufacturers can leverage additive manufacturing to improve performance and enhance patient outcomes.
For more than a decade, the medical field has leveraged additive manufacturing (AM) technology to push the boundaries of patient treatment. From 3D tracheal splints that treat tracheobronchomalacia (TBM) – threatening the breathing of 1 in every 2,000 children worldwide – to 3D printing tissues to test pharmaceuticals, there’s no denying the capabilities and potential of AM.
According IDTechEx, the market for 3D-printed medical devices will be worth $6.1 billion by 2029. Some segments will grow at a compound annual growth rate (CAGR) of 18%. Medical equipment manufacturers who aren’t using 3D printing in some capacity are behind the competition.
Personalized solutions for patients and medical staff are rapidly growing because AM can develop products, tools, and devices that cater to the physiological and functional characteristics of patients and individual providers.
Every patient has unique complex geometries, creating individualized challenges for designs of equipment and tools, functional integration, financial restraints, and compressed delivery times. AM allows healthcare providers to overcome these challenges with personalized patient care.
Custom foot orthotics producer Aetrex captures hundreds of data points from a person’s feet – arch analysis, pressure points – and uses that information to create 3D-printed foam shoe inserts that provide more highly targeted comfort and pressure relief. Applying that type of personalization to a patient confined to a hospital bed or wheelchair means replacing mass-produced products created to meet a broad spectrum of patient specifications, with individual medical equipment fitting their personalized needs. These use cases may exist soon, especially since 3D-printed casts for broken bones already exist.
Similarly, there’s a growing opportunity for medical professionals to experience the same type of customization. A surgeon whose natural way of holding a tool might not necessarily conform to the standard way those tools are created. Tools designed to meet doctors’ unique techniques or patient populations could improve job performance.
Polymer AM enables patient-specific surgical guides and functional prototypes, which can be quickly developed for surgeon design meetings and other testing scenarios.
The flexible printing process allows device providers to easily create equipment customized for each patient or surgeon’s preferred technique by transforming digital files into physical parts.
New AM metal materials with a history of clinical use, such as 17-4PH stainless steel, could support printed-on-demand surgical instruments with the same quality, mechanical properties, and heat treatment used by vendors.
As this space matures, healthcare providers are looking for clarity in keeping up with technology advancements. They’re also seeking the right partners.
One common issue among medical equipment manufacturers is understanding how to implement 3D printing more broadly, not just within certain departments. Organizations typically focus on one need or product line instead of approaching AM more holistically. The most successful organizations have upper management in AM decision-making and roll-out and have multiple department heads representing several disciplines or product lines. This approach better identifies key areas where AM can make a significant impact on operations across the board.
Another hurdle faced during AM implementations is the misconception that materials are cleared by regulatory bodies for general use. The U.S. Food and Drug Administration (FDA) clears devices independently of the manufacturing method. The final finished sterilized device is what is considered biocompatible. AM material suppliers can reduce the legal risk to device manufacturers by testing the biocompatibility of the as-built scenario. However, they don’t have visibility to additional processes that the workpiece touches, so they can’t provide information about the finished device’s biocompatibility.
Medical equipment manufacturers serious about taking advantage of AM’s benefits need an equally engaged partner who brings more to the table than just 3D printers. The right partner will help an organization implement the technology and accompanying procedures to operate more efficiently, better serving client needs.
AM is relatively new and lack of standards to reference can be an impediment. Therefore, it’s important to find a knowledgeable consultant team to ensure success when communicating with regulatory bodies and identifying gaps in quality systems.
If companies can identify products or situations where AM can be applied, they can better set up quality systems to leverage data for fast-follower products in their AM pipeline.
Much of this groundwork is done before production begins. A partner must offer a high degree of engagement on the front end to understand what the producer is trying to accomplish and how to help get there. At EOS, we call this Additive Minds – human-centered design and innovation experts who work to minimize risks while quickly getting to serial production with the greatest possible design freedom.
Once systems are operational, the right partner will help producers think toward future applications and ensure platforms are built to sustain future production needs.
Ideally, an expert partner will also offer education and training opportunities. Whether learning the fundamentals and safety measures or more advanced capabilities of AM machines, they’ll ensure producers get the most out of their investments.
The history of quality offered by experienced AM technology partners, as well as the technology’s ability to create complex geometrical structures, makes it ideal for high-value applications within medical settings. For medical equipment manufacturers, it's important to recognize the powerful capabilities of 3D printing to better serve clients now and into the future.
About the author: Laura Gilmour is the Global Medical Business Development Manager for EOS North America.
Laser manufacturer Foba provided Furtwangen University’s Innovation and Research Center (IFC) Tuttlingen with a laser marking system for medical scientific research and demonstrations.
The first study project was for an applied materials student thesis to develop laser parameter combinations for corrosion-resistant annealing marking on stainless steel instruments using Foba’s M2000-P laser marking system with a Y.0201 fiber laser.
The laser markings’ resistance was verified using a cooking test in accordance with DIN EN ISO 13402. Effects of passivation, necessary for instrument manufacturing, were also taken into account.
The project demonstrated reproducible, corrosion-resistant marking of data matrix codes using various parameter combinations. Data matrix codes were analyzed microscopically, macroscopically, and using a code tester. After a corrosion test and passivation, the codes could easily be read by a blackness measuring device and a code checking device.
The results could help medical instrument and implant manufacturers, providing a basic guideline for suitable parameter combinations. This could aid compliance with marking requirements of the European Medical Device Regulation (EU MDR). All parameters must be individually adapted, depending on each material and application used.
The scientific determination of laser parameters could support a large number of future studies, even ones based on extended corrosion tests, reducing marking time, or to test additional substrate materials. With the large number of metals and plastics used in medical technology, laser marking is a comprehensive research field with a high degree of practical relevance, especially since most of the complex technological processes on the material surface have not been researched in detail.
Foba is using the study results to further develop its own marking software, in particular the function that facilitates user parameters via predetermined values already preset to work with different materials.
The European Medical Device Regulation (EU MDR) 2017/745, fully enacted on May 26, 2020, provides regulations for market surveillance of medical devices to improve patient safety. This also regulates the direct labeling of all products with a unique device identification (UDI/EPN), which contains information on the manufacturer, product, and batch number.
The UDI/EPN is depicted in human readable characters and as a machine-readable two-dimensional data matrix code, and it must be applied directly to the product. This is to ensure that the label remains legible after the outer packaging has been removed and after long-term use.
Laser marking technology can meet the requirements for UDI/EPN labeling, both in terms of quality of the characters and consecutive serial numbering. Appropriate software interfaces transfer the necessary data into the marking process.
The UDI/EPN code is applied to the finished part at the end of the production process and, in the case of stainless steel products, material changes caused by the laser marking on the surface are reworked by passivation, thereby making them corrosion-free.
The power-efficient material could make flexible prosthetics that are 60% lighter than conventional counterparts.
Soft, flexible origami robots, made from paper, plastic, and rubber could support applications including robotic arms, drug delivery, and search and rescue missions. However, sensors and electrical components added on top bulk up devices, lowering utility.
Now, researchers from National University of Singapore (NUS) have developed a method for creating a metal-based material with enhanced capabilities that maintain foldability and reduce weight.
Half as light as paper, the material is more power efficient, making it a strong candidate for light, flexible prosthetic limbs – up to 60% lighter than conventional counterparts. Such prosthetics can provide real-time strain sensing to give feedback on how much they are flexing, giving users finer control and immediate information without using external sensors which would add unwanted weight.
This lightweight metallic backbone is at least 3x lighter than conventional materials used to fabricate origami robots and is more power- efficient, lowering energy use 30% while speeding operation.
Produced through graphene oxide-enabled templating synthesis, cellulose paper is soaked in a graphene oxide solution before being dipped in a solution made of metallic ions such as platinum. The material is then burned in inert argon at 800°C and then at 500°C in air.
The final product is a 90µm layer of metal made of 70% platinum and 30% amorphous carbon (ash) that’s flexible enough to bend, fold, and stretch. Other metals such as gold and silver can also be used.
Team leader and NUS Chemical and Biomolecular Engineering Assistant Professor Chen Po-Yen used a cellulose template cut out in the shape of a phoenix for his research, explaining that they were “inspired by the mythical creature. Just like the phoenix, it can be burnt to ash and reborn to become more powerful than before.”
The team’s material can function as mechanically stable, soft, and conductive backbones that equip robots with strain sensing and communication capabilities without the need for external electronics – the material acts as its own wireless antenna, communicating with a remote operator or other robots without external communication modules.
“We experimented with different electrically conductive materials to finally derive a unique combination that achieves optimal strain sensing and wireless communication capabilities…expanding the library of unconventional materials for the fabrication of advanced robots,” says Yang Haitao, doctoral student at NUS and first author of the study.
Next, Chen and his team are looking at adding more functions to the metallic backbone. One promising direction is to incorporate electrochemically active materials to fabricate energy storage devices, allowing the material to be its own battery. The team is also experimenting with other metals such as copper, which will lower the cost of material production.
National University of Singapore (NUS)
WATCH TO LEARN MORE: https://youtu.be/TAprG0J-rmk
Duraglide Dry Lubricant lubricates assemblies that slide, pivot, or twist, eliminating stiction and improving actuation in catheters, cutting tools, staplers, and hypo tubes. Using polytetrafluoroethylene (PTFE) particles applied in a dispersion fluid, the non-migrating, fast-drying fluid leaves a smooth, slippery, uniform coating on any surface. ISO 10993 certified, Duraglide is compatible with most metals and plastics, penetrates complex shapes, and improves device performance by reducing actuation forces up to 25%. It’s hostile to bioburden and compatible with sterilization processes.
MicroCare Medical MD&M West 2020 booth #2343 & #618
Tecna leak testers verify integrity of medical products, performing leak and flow tests as well as volume and resistance (burst tests) for sealed products at interception and under vacuum. Tecna’s primary instruments include:
Marposs MD&M West 2020 booth #1337
At MD&M West 2020, Marposs will also show:
Aeroel laser micrometers for non-contact diameter measurement for gaging plastic extrusion of tubes, other materials
OptoFlash 2D for inspecting small-size shafts, fasteners, dental implants