A 360-degree look at resin conveying systems: types, operation, economics, design, installation, components and controls.
This Knowledge Center provides an overview of resin moisture and the drying process, including information on the best drying practices for your manufacturing facility. Metal Frame Mesh
Everything you need to know about plastics compounding technology—from feeding solutions to application profiles and expert advice.
Combat the skilled labor shortage using this comprehensive resource to train your own plastics processing experts.
Deep dive into the basics of blending versus dosing, controls, maintenance, process integration and more.
This Knowledge Center provides an overview of the considerations needed to understand the purchase, operation, and maintenance of a process cooling system.
Learn about sustainable scrap reprocessing—this resource offers a deep dive into everything from granulator types and options, to service tips, videos and technical articles.
While price initiatives for PE and PVC were underway, resin prices had rollover potential for first two months of 2024, perhaps with the exception of PET.
Flat-to-downward trajectory for at least this month.
A mixed bag, though prices likely to be down if not flat for all this month.
Trajectory is generally flat-to-down for all commodity resins.
Flat-to-down trajectory underway for fourth quarter for commodity resins.
Generally, a bottoming-out appears to be the projected pricing trajectory.
Resin drying is a crucial, but often-misunderstood area. This collection includes details on why and what you need to dry, how to specify a dryer, and best practices.
Take a deep dive into all of the various aspects of part quoting to ensure you’ve got all the bases—as in costs—covered before preparing your customer’s quote for services.
In this collection of articles, two of the industry’s foremost authorities on screw design — Jim Frankand and Mark Spalding — offer their sage advice on screw design...what works, what doesn’t, and what to look for when things start going wrong.
In this collection, which is part one of a series representing some of John’s finest work, we present you with five articles that we think you will refer to time and again as you look to solve problems, cut cycle times and improve the quality of the parts you mold.
Gifted with extraordinary technical know how and an authoritative yet plain English writing style, in this collection of articles Fattori offers his insights on a variety of molding-related topics that are bound to make your days on the production floor go a little bit better.
In this three-part collection, veteran molder and moldmaker Jim Fattori brings to bear his 40+ years of on-the-job experience and provides molders his “from the trenches” perspective on on the why, where and how of venting injection molds. Take the trial-and-error out of the molding venting process.
Mike Sepe has authored more than 25 ANTEC papers and more than 250 articles illustrating the importance of this interdisciplanary approach. In this collection, we present some of his best work during the years he has been contributing for Plastics Technology Magazine.
In this collection of content, we provide expert advice on welding from some of the leading authorities in the field, with tips on such matters as controls, as well as insights on how to solve common problems in welding.
Mold maintenance is critical, and with this collection of content we’ve bundled some of the very best advice we’ve published on repairing, maintaining, evaluating and even hanging molds on injection molding machines.
Thousands of people visit our Supplier Guide every day to source equipment and materials. Get in front of them with a free company profile.
Medical-component specialist LightningCath has carved a niche meeting the needs of small to medium-sized entrepreneurs with complex catheter designs … quickly.
Plastics Technology is closing in on its 70th anniversary. Here are some of Editorial Director Jim Callari’s observations to commemorate the occasion.
As with everything else, there are pros and cons, but more of the former. They provide processors higher rates while decreasing the temperature of the extrudate while enabling downgauging.
The drop in plastics activity appears to be driven by a return to accelerated contraction for three closely connected components — new orders, production and backlog.
Beginning the first of this year, 12 states are following EPA bans on potentially damaging cooling fluids. Chiller suppliers have adjusted equipment designs to accommodate the new regulations. Here’s what all this means to processors.
Pairing external big picture training with internal job-specific instruction can help your process technicians meet quality expectations as well as production targets.
In less than a decade in injection molding, US Merchants has acquired hundreds of machines spread across facilities in California, Texas, Virginia and Arizona, with even more growth coming.
Demand for bioresins is growing in molded goods, particularly as a sustainability play to replace fossil-fuel based materials, but these materials are not a drop-in replacement for traditional materials. Molds and hot runners need to be optimized for these materials.
There are many things to consider, and paying attention to the details can help avoid machine downtime and higher maintenance costs — and keep the customer happy.
Flat-to-downward trajectory for at least this month.
Topping five other entries in voting by fellow molders, the Ultradent team talks about their Hot Shots sweep.
Serendipitous Learning Opportunities at PTXPO Underscore the Value of Being Present.
Introduced by Zeiger and Spark Industries at the PTXPO, the nozzle is designed for maximum heat transfer and uniformity with a continuous taper for self cleaning.
Ultradent's entry of its Umbrella cheek retractor took home the awards for Technical Sophistication and Achievement in Economics and Efficiency at PTXPO.
technotrans says climate protection, energy efficiency and customization will be key discussion topics at PTXPO as it displays its protemp flow 6 ultrasonic eco and the teco cs 90t 9.1 TCUs.
Shibaura discusses the upcoming Plastics Technology Expo (PTXPO) March 28-30
Competition will invite participants to help reshape life cycle management in plastics.
Sign up to attend North America’s leading trade show for plastics.
Offerings range from recycled, biobased, biodegradable and monomaterial structures that enhance recyclability to additives that are more efficient, sustainable and safer to use.
Ahead of the first NPE since 2018, PLASTICS announced that its triennial show will stay in Orlando and early May for ’27, ’30 and ’33.
New features of NPE2024 aim to “bring the whole plastics ecosystem together to innovate, collaborate and share findings.”
Hundreds of tons of demonstration products will be created at NPE2024 next spring. Commercial Plastics Recycling strives to recycle all of it.
Mixed in among thought leaders from leading suppliers to injection molders and mold makers at the 2023 Molding and MoldMaking conferences will be molders and toolmakers themselves.
After successfully introducing a combined conference for moldmakers and injection molders in 2022, Plastics Technology and MoldMaking Technology are once again joining forces for a tooling/molding two-for-one.
Multiple speakers at Molding 2023 will address the ways simulation can impact material substitution decisions, process profitability and simplification of mold design.
When, how, what and why to automate — leading robotics suppliers and forward-thinking moldmakers will share their insights on automating manufacturing at collocated event.
As self-imposed and government-issued sustainability mandates approach, injection molders reimagine their operations.
August 29-30 in Minneapolis all things injection molding and moldmaking will be happening at the Hyatt Regency — check out who’s speaking on what topics today.
Get your clicking finger in shape and sign up for all that we have in store for you in 2023.
Molding 2023 to take place Aug. 29-30 in Minnesota; Extrusion 2023 slated for Oct. 10-12 in Indiana.
Key technologies — such as multicolor molding, film molding and PUR overmolding for both exterior and interior applications — are at the forefront of this transformation. Join this webinar to explore the vast potential of eMobility in molding large components — including those with fiber reinforcements — thereby driving the need for large injection molding cells with a clamping force of up to 11,000 tons. You will also gain insight into Engel's innovative two-stage process, a solution for future recycling processes. This webinar will provide an in-depth overview of challenging applications, production concepts and best practices, including: BMW iX front panel production cell Smart rear panels concept based on IMD and 2C molding Sustainability concepts based on two-stage process Large tonnage equipment for battery moldings
In today's manufacturing environment, robust processes that meet strict industry and regulatory standards are essential. With the advent of servo-driven ultrasonic welding technology, enhancing product quality and maintaining consistency has become remarkably effortless. Discover the fundamentals of ultrasonic welding, delve into vital components within these systems, explore how servo-driven ultrasonic welding enhances weld quality via advanced control features and gain insights into optimizing your assemblies for welding in these high-performing machines. Join Dukane to unlock the potential of ultrasonic welding in modern manufacturing for plastic devices and components. Agenda: Fundamentals of ultrasonic welding Key components in an ultrasonic welding system Using servo-driven ultrasonic systems to control your welding process Designing your parts and components for servo-controlled ultrasonic welding
This webinar will help you make informed decisions to confirm the equipment access stairs in your facility are OSHA compliant and meet the highest standards of safety and ergonomics. Agenda: Identifying opportunities to increase safety in the work place Utilizing space saving stairways Ensuring code compliance for equipment access
4.0, EUROMAP, OPC, OLE, QC, DSN, SQL, VNC, MES, ERP, FTP, CMS, SPI — are you confused by all buzzwords being tossed around in the plastics industry? Not convinced the data collection is necessary? Or are you unsure of how it could be implemented and improve your molding processes? Wittmann has been on the cutting edge of the data collection push for nearly 20 years. In this webinar, take a step back from the idea of the manufacturing facility of the future and discuss what you can do today to improve your process. Using readily-available technology, Wittmann can help reduce downtime, limit scrap and wasted material, and predict required maintenance. Let the experts at Wittmann help you understand: what data can be collected, what that data can be used for, what systems are used, and how to implement them. Agenda: Demystifying the terminology Tracking the material flow and lot information through the material handling system The data available from various auxiliary equipment, such as: dryers, blenders, mold temperature controls and robots Automating the process through changes in the data collected at the machines during production Adding visualization to increase productivity
Learn how targeted, modular, dosing and blending solutions — covering powders, granules, regrinds and liquids — provide plastics processors of all kinds with best-in-class accurate dosing while delivering significant raw material savings and ensuring highest quality. Agenda: Introduction to Movacolor Blending in plastics applications Movacolor feeding and dosing technology Hybrid blending to combine high material throughput and dosing accuracy
This presentation will explore the in-situ polyurethane (PU) overmolding of injection-molded and composite parts, allowing for direct out-of-mold class "A" surfaces. KraussMaffei will review the process and equipment required. It will also discuss tooling types currently available for PU systems for this process. KraussMaffei will compare the pros and cons of this technology over currently-available coating and painting systems. Agenda: Introduction and evolution of the ColorForm technology Overview of the ColorForm process Equipment required Tooling and PU systems Benefits of the system compared to typical spray-applied coatings Pros and cons of the technology
The global plastics industry has been navigating through what is arguably the most volatile period in decades. Unprecedented amounts of new production capacity are scheduled to start in North America, Europe, and China in the near term and compete for demand during a period of economic challenges. How will trade flows shift? Will this lead to regional cost disparities and rationalization? Energy transition and sustainability targets continue transforming the plastics market and increasing the competitive landscape. As the market evolves, what impact will new technology, policy, regulation, the growing role of chemicals versus fuel and other factors have on industry restructuring and business models? At GPS 2024, leading global experts will come together to discuss pivotal impacts and initiatives shaping the plastics industry. Join us and participants from across the globe to gain the latest insight and deep analysis as you connect with your peers and industry professionals. This year’s conference will explore the theme Disruptive Global Dynamics Reshaping Plastics and include a full day workshop focused on the Global Plastics Business and Plastics Transition to Circularity, 1.5 days of expert content and numerous networking functions.
Every three years, leaders from almost every major industry gather at NPE to advance their businesses through innovations in plastics. The largest plastics trade show in the Americas, NPE offers six technology zones, keynote speakers, workshops and opportunities to build partnerships.
The 3D Printing Workshop @ NPE2024 – The Plastics Show, is an immersive, half-day workshop focused on the emerging possibilities for part production via 3D printing and additive manufacturing. Presented by Additive Manufacturing Media, Plastics Technology and MoldMaking Technology, the 3D Printing Workshop will build upon a successful model first introduced at IMTS 2014. Attendees will benefit from a program focused on practical applications of 3D technologies related to plastics processing. This event will conclude with a 3D Printing Industry Reception sponsored by Additive Manufacturing Media.
The Society Plastics Engineers (SPE) Extrusion Division and the SPE Eastern New England Section will co-host the Screw Design Conference-Topcon on June 19-20, 2024 @ UMass Lowell in Lowell, MA. This highly technical program will focus upon screw design principles for single and twin screw extruders with wide ranging topics relating to screw designs for feeding, melting, mixing, venting and pumping plastics products and parts. Areas of focus will include screw designs for melt temperature and gel management, gel minimization, bioplastics, recycled materials and foaming. In addition to the technical sessions, a tour of the UMass Lowel Plastics Processing Laboratories will be integrated into Day 2 of the event. This program is not just for screw designers, but to help anyone responsible for any type of extrusion operation to evaluate existing extrusion equipment; and also to prepare for future projects. Price to attend: Less than $1000! Registrations will be accepted in early 2024. Call for papers – To be considered to give a presentation, please submit a talk title and abstract on or before December 15 to: Technical Chair: Eldridge M. Mount III, e-mail emmount@msn.com Corporate sponsorships - A limited # of corporate sponsorships (15) are available on a 1st come basis. Included is a 6’ tabletop display (must fit on table), denotation in all promotional activities, and 1 no charge registration. To become a sponsor contact: Charlie Martin, Leistritz Extrusion, e-mail cmartin@leistritz-extrusion.com, cell 973-650 3137 General information: A reception on Day 1 and a tabletop display area will allow the attendees to meet and discuss state-of-the-art screw technologies with industry experts. The SPE Extrusion Division will issue a “Screw Design Certificate” to all participants who have attended the program. Students are encouraged to attend and will receive a discounted rate. For additional information contact: Program Chair: Karen Xiao, Macro Engineering, KXiao@macroeng.com
Debuting in 2010, the Parts Cleaning Conference is the leading and most trusted manufacturing and industrial parts cleaning forum focused solely on delivering quality technical information in the specialized field of machined parts cleansing. Providing guidance and training to understand the recognized sets of standards for industrial cleaning, every year the Conference showcases industry experts who present educational sessions on the latest and most pressing topics affecting manufacturing facilities today. Discover all that the 2022 Parts Cleaning Conference has to offer!
Presented by Additive Manufacturing Media, Plastics Technology and MoldMaking Technology, the 3D Printing Workshop at IMTS 2024 is a chance for job shops to learn the emerging possibilities for part production via 3D printing and additive manufacturing. First introduced at IMTS 2014, this workshop has helped hundreds of manufacturing professionals expand their additive capabilities.
The screen changer plays an essential role in generating quality extrudate. Here’s what you need to know to keep it functioning properly.
One way to minimize leakage on slide-plate screen changers is to increase the head pressure. While that might sound counter-intuitive, because the seals are designed to respond to pressure in the extruder, they are only working at their peak when the pressure is higher.
Continuous screen changers that use no mechanical seal utilize precisely machined clearances to effect a polymer seal. These same clearances provide lubrication between the bolts or wheel and housing and must be maintained to avoid locking up the machines.
Manual screen changers provide cost-effective filtration for extrusion. Changeovers are simplified and downtime is reduced because the design permits the extruder screw to be pulled through the screen changer.
So-called extended-area screen changers are suited to extremely high-capacity applications in compounding and recycling.
There are many different designs of screen changers on the market today, from manual slide plates to constant-pressure and continuous backflush or scrapper designs, and each one comes with its own set of strengths and weaknesses. As a processor, you need to know these in order to make the best choice of screen changer for your particular application.
This article will focus more on general process troubleshooting as opposed to machine-specific issues, but it’s important to note that a large percentage of problems that extrusion processors have with their screen changers occur because the screen changer they’re using is not the best design for their application. Each specific extrusion filtration application should be closely examined prior to specifying a screen changer for the project.
FILTRATION MESH Every processor wants the best filtration they can get for the area of filtration they have. Very few, however, utilize a screen-pack configuration fully optimized for their process. Take as an example a situation in which an operator is attempting to extend a production run between screen changes. As the screen becomes occluded, head pressure rises and eventually causes the wire cloth to fail. A simple operator solution is to pile on additional 20-mesh screens for increased strength.
A better solution would be to increase the support strength of the base screen, using a heavier-gauge 10-mesh screen layered with a single 20-mesh screen. The 10- and 20- mesh screens will support each other by working at two levels. The end result is the ability to run longer between changes, but without the unnecessarily high pressure drop and resulting increase in shear heat. Any increase in pressure-induced shear is best avoided, since this will generate higher melt temperature at the discharge end of the extruder, creating a higher demand on downstream cooling capacity and potentially reducing output.
Most screen-changer suppliers offer process-support services that include pressure-drop calculations. These are simple to perform and factor in material viscosities, breaker-plate open area, and screen open area to arrive at the best screen-pack configuration for the process and operating environment. This service is normally a free and simple means to optimize polymer flow performance.
TEMPERATURE CONTROL Another issue occasionally attributed to screen changers is temperature fluctuation. Best practice is to stay alert to gauges, heaters, and heater circuits. Monitoring these on the screen changer may not be as critical as checking the extruder and feed screw, but it can help spot an issue before it becomes catastrophic.
Another tip is to optimize the number of heat zones necessary to balance temperature across the screen changer. More specifically:
• Hydraulic slide-plate screen changers are best served by three zones—a body zone and independent zones for the each end of the slide plate. Many processors wire these machines into a single control zone, resulting in too much or too little heat to the slide plate. This can destabilize the melt profile and cause material burning in the off-line breaker plate.
• Continuous bolt-type screen changers are normally best served by a single control zone, but as these machines increase in size, additional body zones help balance the heat. Bolt-type continuous screen changers heat the bolts by conduction from the body. If heat is unbalanced, the body can shrink onto the bolt and generate high enough clamping forces to prevent movement of the bolt.
• Machine adapters are also normally best served with independent heat control. This, however, will vary with size.
PRESSURE FLUCTUATION Streamlining the polymer flow through the screen changer will also affect process stability. For sensitive materials or those with unique flow characteristics, CFD (computational fluid dynamics) modeling software can be utilized to optimize screen-changer flow passages and minimize material residence time. Along this line, adapter length, steps and transitions, and polymer inventory between the screw tip and screen pack can be critical to establishing best flow while minimizing polymer degradation points and thermal stratification.
Vent cycles on continuous screen changers can influence pressure stability. Most bolt-type screen changers can see up to 50% of the available filter area removed from the process for screen change. While this naturally causes a rise in head pressure, the flow rate and die pressure normally remain relatively stable. The issue arises with the reintroduction of the clean screen. Vents machined into the bolts divert a small portion of the polymer melt to prefill and purge air from the incoming screen pocket. The resulting slight drop in die pressure can be minimized by operator finesse or more precisely by PLC control. Constant-pressure screen changers, such as rotary wheel designs, are not normally subject to these issues. One auxiliary that can help tremendously with fluctuating pressure is a gear pump, which can tolerate upstream pressure swings while holding the die pressure stable.
LEAKAGE Leakage is a problem with almost all screen changer designs as they age, but most noticeably with slide-plate models. This type of screen changer relies on manually adjusted or pressure-activated seals and is subject to wear and tear from the movement of the slide plate, degradation of the seal-pressure ring, and damage from dislodged screens. Seal maintenance for these machines can be required as often as weekly to once a year. Maintenance can lead to teardown and reassembly, which can be a time-consuming, expensive process. Even before it reaches this point, the housekeeping required to keep the slide plate clean and prevent polymer from leaking onto wiring and other equipment is significant.
One way to minimize leakage on a system like this is to increase the head pressure. Your intuition might tell you lower pressure would be better because it would put less strain on the system. However, because the seals are designed to respond to pressure in the extruder, they are only working at their peak when the pressure is higher. At a lower pressure, the seals will relax slightly. When the extruder is idle or running at drool speed and there is very little pressure being exerted on the seal, it becomes easy for lower viscosity material to leak out. One newer slide-plate seal, an all-steel, segmented pressure-ring design, addresses these problems and caries a lifetime leak-free warranty regardless of temperature and low viscosity, making this seal the first to operate leak-free on high-temperature coating applications.
Material leakage on bolt-type or other close-tolerance rotary wheel machines that operate without a mechanical seal can likewise occur over time; but with these designs, leakage is almost always caused by mechanical damage. These precision-machined screen changers are typically designed for a fairly narrow material viscosity range.
As such, you should not apply a machine designed with clearances for high pressure and high viscosity to a low-viscosity process without approval or modification from the supplier.
RESIN CONTAMINATION, DEGRADATION The primary purpose of a screen changer is to filter out contaminants from the melt stream; but the fact is, screen changes almost inevitably introduce contaminants, some of which get into the die. These result from imperfect cleaning of the slide plate, bolt, or wheel. For example:
• This can occur on a slide-plate screen changer as the upstream and downstream seals scrape material residue into both sides of the oncoming screen pocket. Upstream contaminants are caught on the screen. Downstream contaminants flush out into the die.
• A continuous or constant-pressure screen changer can experience this as well, but to a much smaller degree. The gap between the bolt or wheel and housing is measured in microns on the downstream side. The rare contaminant that makes it through this clearance to enter the melt flow is only consequential to the most demanding of applications, and for these few occasions, secondary, long-life canister filters will catch anything that comes through.
Many processes do not have to run continuously or require 100% quality and can overlook contaminants during screen change. However, if your customer has zero tolerance, you’ll need a different kind of screen changer. There is no way to continue using a slide-plate screen changer without introducing some level of contaminants or material degradation from the offline breaker plate. To solve this, a continuous bolt-type or rotary-wheel screen changer is a better solution.
LOCK-UP Continuous screen changers that use no mechanical seal utilize precisely machined clearances to effect a polymer seal. These same clearances provide lubrication between the bolts or wheel and housing and must be maintained to avoid locking up the machines. Lock-up (jammed bolt or wheel) can be a result of various things, usually preventable with correct operator usage. The leading cause of lock-ups occurs when the bolts or wheel are not cleaned and lubricated regularly.
Many processors with a bolt-type or rotary-wheel screen changer have bought these continuous-process machines because they have no mechanical seals and run reliably and leak-free for years on end. While these advanced designs certainly require less upkeep than a slide plate, maintenance during screen change should not be neglected.
Over time, excess buildup of polymer can plate onto the bolt or wheel surfaces, reducing required clearances and eventually requiring more hydraulic pressure to shift than is available from the power unit or mechanical drive.
This stuck bolt or wheel is easily preventable with regular cleaning. A lock-up requires a shutdown and reheat process that can take up to 8 hr or more. Doing daily maintenance and cleaning of the piston takes 5 to 10 min and can save a considerable amount of downtime. “The biggest issue is getting into the mindset of cleaning the whole bolt,” says Marty Danco of Verity Resins, a recycler and compounder based in Forest City, N.C. “When you lock it up, there’s no way home, it’s locked up for good. Using proper copper gauze, the bolt should be cleaned every day—not just the top, but underneath it and on the sides.”
The necessity of regular maintenance also holds for breaker plates. Over time, material will carbonize on them, closing off the holes, which raises head pressure and eventually compromises output. Breaker-plate clogging is also easily preventable. The best solution is to make sure to have a clean spare. Swapping these breaker plates out even once a week is great preventive maintenance to ensure it never reaches the point where the process or the final product is impacted.
Most leading screen-changer suppliers are excellent resources to refer your troubleshooting issues to. Doing so, instead of relying solely on your maintenance crew, can often reduce your downtime and repair expenses, eliminate some problems before they occur, and potentially point you to a better process solution than the machine currently in service.
Don Macnamara is general manager at PSI-Polymer Systems Inc., Conover, N.C., and is a 32-year veteran of the plastics industry with more than 20 years’ direct experience in polymer filtration at Beringer, Merritt-Davis, and PSI. Bart Jones is the founder and former owner of Extek Screen Changers and is an active consultant to PSI-Polymer Systems. Contact: (828) 468-2600; dmacnamara@psi-polymersystems.com; psi-polymersystems.com.
If you don’t baseline your extruder, then how are you going to set realistic expectations for its performance? Here's how to get going.
All things being equal, PET will outperform PBT mechanically and thermally. But the processor must dry the material properly and must understand the importance of mold temperature in achieving a degree of crystallinity that allows the natural advantages of the polymer to be realized.
Moisture in PET will result in degradation that will foul up sheet and thermoformed products. Keep it at bay by following these tips when drying APET virgin and flake material.
Putting one or two vents between the feed throat and die is a good way to remove moisture, trapped air, and other volatiles from melted plastic as it moves through an extruder.
Extruder screws and barrels will wear over time. If you are seeing a reduction in specific rate and higher discharge temperatures, wear is the likely culprit.
You can better visualize the melting process by “flipping” the observation point so that the barrel appears to be turning clockwise around a stationary screw.
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