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. Twin Screw Extruder Machine
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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.
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.
PS prices to see significant drop, with some potential for a modest downward path for others.
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.
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.
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
Consistent quality is paramount within the production of pipe and tubing applications. Additionally, significant material savings can be obtained by tightly controlling product dimensions with the correct process equipment. In this webinar, Conair will cover gravimetric control of an extruder and production line speed to ensure optimal quality and cost savings are achieved in your product run. A detailed discussion of the upstream material handling system includes: blending resins upstream of the feed throat, detection of the extruder rate at the throat, control of the extruder rpm and control of the product itself in feet per min — all accomplished with a simple recipe configuration which includes product weight per length desired and production line speed.
Medical-component specialist LightningCath has carved a niche meeting the needs of small to medium-sized entrepreneurs with complex catheter designs … quickly.
Fast Track service from BPM can repair every brand of rotor in two weeks or fewer.
Adds 52,000 square feet to Lebanon plant.
Nextpoint announced a $2 million investment, part of a $7.7 million raise for PlantSwitch, which uses agricultural waste to manufacture plastic.
Life cycle analysis of production at four plants in Mexico and Germany was conducted by C7-consult.
Tahara’s new eight-head, double-sided coex machine has many new mechanical and electronic features.
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
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.
After what will be a 6-year hiatus caused by the COVID-19 pandemic, registration is open for the triennial show, which will take place May 6-10, 2023, in Orlando, Florida.
The Plastics Industry Association has hired from within, elevating Matt Seaholm to CEO and Glenn Anderson to COO.
Long-time leaders hailing from the U.S., Japan, Germany and Austria and across the entire supply chain, from machinery and materials to training and moldmaking, will be inducted.
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
Fast facts SPE International Polyolefins Conference 2024: The Preeminent Polymer Conference in the World dedicated to Polyolefins since 1975 The conference will in-person and virtual The powerful software platform for the conference will allow access to all papers on-demand, even several months after the conference, access to the program, access to virtual exhibitor/sponsor booths, and easy communication with speakers and other participants In-person participants can download a mobile or web app for the conference to access all the features of the software platform for the conference We anticipate over 900 people from around the globe to participate in-person or virtually The improved layout of the exhibit floor offers easy access and flow for the 60+ companies that we anticipate to exhibit Over 20 sponsors expected 150+ Technical papers, Sunday afternoon Tutorial Student Poster Competition 2 Networking Socials Meeting rooms available for rent to meet with customers and suppliers Exhibits from Monday through Wednesday until noon The Conference is organized by the SPE South Texas Section, the SPE Polymer Modifiers and Additives Division, the Thermoplastic Materials and Foams Division, the Engineering Properties and Structures Division, the Building and Infrastructure Division, and the Flexible Packaging Division.
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!
In pipe extrusion, selecting or building a complementary set of tooling often poses challenges due to a range of qualitative factors. Here’s some guidance to help you out.
Selecting the right extruder and downstream equipment are two prerequisites for the successful installation and operation of a new pipe extrusion line. However, there’s a third, vitally important factor: the right tooling.
Consisting of the pipe die, calibration/sizing tooling, cooling system and downstream supports, extrusion tooling makes all the difference between a pipe production line that should work, and one that works optimally. Pipe tooling is to a pipe production what an assembly line is to the quality of a car or appliance: It’s the element that receives the essential parts of the product (for example, heated and extruded material flows, colors, markings and more) and assembles, aligns and shapes them into a finished product.
With all other upstream and downstream equipment being equal, deviations in tooling specification, manufacturing or tolerances will result in measurable differences in the fit, finish and yield of your final pipe product, or in production failures and the need to retool.
Many of the factors needed to specify optimal pipe tooling are the same ones required for selecting the extrusion line and downstream equipment. They are:
FIG 1 Cross section of a single-layer pipe head, showing how the melt from the extruder splits when it reaches the die pin and is then channeled into a series of flow paths that later merge to form the circumference of the extruded pipe. Photo Credit: Conair
However, some customers elect to run multilayer pipe using these materials. The most typical multilayer pipe consists of three layers, with a center layer of regrind delivered from one extruder that is sandwiched between two layers of virgin material delivered by another extruder, with all of the materials coming together in a multilayer pipe die (Figure 2). Other multilayer pipes may combine two or more materials, consisting of a base material layer with additional layer(s) of a different material with barrier properties.
FIG 2 Multilayer pipe die. Photo Credit: Conair
When inline printing is not possible, it becomes necessary to use a multilayer extruder, with an additional small extruder that embeds colored markings or stripe(s) into the surface of the extrudate before it enters the pipe head.
Pipe heads are typically designed to accommodate a range of pipe sizes and outputs. Some typical output ranges are listed in the accompanying table above, based on a standard dimension ratio (SDR) of 11, a very common SDR that means the pipe sidewall thickness is equal to 1/11th of the pipe diameter.
As the first major piece of tooling, the pipe head receives a flow of molten plastic from the extruder, then distributes that flow outward into a circular pattern that forms the shape of the pipe. A well-designed pipe head works with the extruder to move the plastic through the pipe die evenly, without generating excessive pressure that could begin to distort the pipe dimensions. There are several major factors involved in selecting the right pipe head:
Spider or spiderless/basket design: The first key variable in the pipe head is the internal configuration that holds the die pin inside the melt flow to form the inner diameter (ID) of the pipe. Pipe dies feature two basic designs, each of which offers extrusion challenges but can be optimized for particular types of material.
Spider-type pipe heads were developed first, with spiderless pipe heads evolving later to cope with different materials and pipe requirements. One key difference is in the heat tolerance of the materials you’re extruding. Generally, rigid PVC extrudes very smoothly through a spider-type pipe head. However, to extrude polyolefins like HDPE and PP, a basket design is preferred. The difference is in the polymer molecule — polyolefins have a more stable molecular structure, so they can tolerate the more restrictive basket flow channels, while PVC tends to degrade and burn when pushed through more restrictive die flow channels.
Land length: Land length refers to the length of the area of the pipe head where the pin and bushing run parallel to each other. Getting this length right is essential to stabilizing the melt as the pipe begins to form, prior to exiting the pipe die. Too little land length can cause the pipe shape to vary as it leaves the die, resulting in dimensional instability. But too much can create resistance (backpressure) which can restrict die output. A general guideline for producing HDPE pipe is a 30:1 ratio of land length to wall thickness.
Internal air cooling: Because of the mass of hot extrudate in a larger pipe size, external cooling alone is insufficient to cool and stabilize pipe dimensions when pipe exceeds 10 inches in diameter. So, an internal flow of cooling air, delivered through the die head, is used to carry away internal heat while providing positive pressure to maintain the ID of the pipe during vacuum sizing. The hot air flows through and out of the pipe as it moves further downstream. The practical effect of internal cooling is that it can save extrusion floor space by reducing the number or length of external cooling tanks required.
Remember that tooling helps to assemble and transition the elements of the extrusion as they proceed down the line. One of the most visible and critical requirements of tooling is to manage the flow of “hot” pipe material as it exits the pipe head and then rapidly “draws down” to enter calibration tooling, which begins the sizing and cooling process.
Material Drawdown: “Drawdown” refers to the degree to which a “hot” pipe extrusion shrinks or “necks down” between the exit of the pipe head and the entrance of the sizing tooling, specifically the neck of the calibration sleeve on the vacuum cooling tank. To enable drawdown, the pin and bushing back in the pipe head are engineered to be larger than the nominal pipe size being produced. Ideally, the excess in size enables the melt flow to cool and shrink (drawdown) just enough to “seal” the circumference of the pipe as it enters the calibration sleeve — which is the first element of vacuum sizing tooling.
If the hot pipe exits the head being too small (not enough estimated drawdown), it won’t complete the tooling seal needed for vacuum sizing to optimize its dimensions during cooling. This will result in leakage of lubricating water from the neck of the calibration tool. If the pipe comes out too large (too much estimated drawdown), the melt will jam at the entrance of the sizing tool. Such jamming causes uneven stress in the molecular structure of the pipe and can result in reduced burst strength and other problems.
The degree of drawdown is substantial and material specific, so predicting and engineering extrusion tooling to get it right can be time-consuming. However, there are some general guidelines, based on experience: Drawdown on polyolefins generally ranges from 30% to40%, while PVC draws down 15-20%, for example. Watching material shrink so much in the few inches of open air between the pipe head outlet and the neck of the sizing tool really brings home the importance of getting drawdown right.
FIG 3 Placed at the entrance to a vacuum cooling tank, calibration sleeves receive the hot extrudate from the pipe die. All along the sleeve structure, openings or grooves in or between the sleeve segments admit spray cooling water to help stabilize the pipe surface as it passes through the tank. Photo Credit: Conair
Calibration tooling. As the hot pipe material draws down, it enters a calibration sleeve, which is mounted at the entrance of a vacuum cooling tank. The calibration sleeve (Figure 3) is expected to perform a range of vital tasks and therefore relies on a series of design elements:
With so much going on within the calibration sleeve, one might wonder if the work of sizing the pipe is done in a single step with the calibration sleeve. That’s not so. Especially on fast-moving, high-output extrusion lines, the calibration sleeve only “sets the skin” on the outermost material or layer of the pipe, stabilizing it so the pipe can undergo subsequent cooling.
Vacuum tank tooling: Initial water cooling for pipe is provided in one or more vacuum cooling tanks (additional nonvacuum cooling tanks may also be required.) When vacuum is applied to the exterior of the hot pipe, airflow within the pipe exerts relative positive pressure to maintain the ID of the pipe.
Because of the mass of material in larger size pipes, pipes can take a long time to cool, shrink and harden to finished size. So, it is vital to have another set of properly adjusted tooling — pipe supports — within the vacuum cooling tank and other downstream tanks, when those are necessary. Pipe supports that are shaped to the pipe OD, acting as an extension of the sizing tool, must follow the sizer to maintain the OD of the pipe as the melt continues to cool. Often, the need for these supports is overlooked or treated as an afterthought in the design of an extrusion tooling package, but they’re vital.
Experience shows that solid supports, properly sized and formed of materials like UHMW PE (for good surface lubricity) offer a superior combination of stability and support within a cooling tank (Figure 4). Some might suggest using rollers within vacuum or cooling tanks, but rollers can move and shift due to the size and mass of the pipe, resulting in irregularities or flat spots on the pipe surface.
FIG 4 Vacuum cooling tank with external spray nozzles (red) and solid pipe supports (yellow). The sturdy yellow pipe supports perform better than rollers, especially with larger pipe sizes. Photo Credit: Conair
Though immersion-style cooling tanks work well with small tubing, they are impractical for large extruded pipe for two reasons: First, larger pipes hold a significant volume of air, which makes them too buoyant to move smoothly through an immersion cooling process. The preferred cooling method for large extruded pipe, external spray cooling, reliably dissipates surface heat while preventing stratification layers in the cooling water — the other problem with immersion cooling.
On larger pipe sizes, usually 10 inches in diameter or greater, external cooling is supplemented by internal air cooling, which is delivered through the die head and flows downstream through the pipe (Figure 5).
FIG 5 A typical internal pipe cooling system consists of a centrifugal blower delivering a stream of cool air through the pipe head and into the pipe ID. Internal cooling is common on extruded pipe of 10 inches in diameter and above. Internal cooling can save floor space by reducing the length of the required cooling tanks. Photo Credit: Conair
Like other forms of extrusion, successful pipe extrusion is accomplished by understanding and controlling multiple factors in the process. Generally, it is possible to size the pieces of equipment in an extrusion line based on quantitative factors such as dimensions, tolerances and output. However, selecting or building a complementary set of tooling often poses additional challenges due to a range of qualitative factors: polymer characteristics, tooling design and materials, drawdown, process temperatures, cooling methods, cut methods and more.
While extrusion processing norms may sometimes point the way to the right solutions, empirical knowledge developed over time to better understand these qualitative factors can make all the difference in successfully defining and operating a pipe extrusion line.
About the Authors: Ernie Preiato recently retired as vice president, extrusion, for Conair, following a 50-year career, most of which was spent at Conair. Chris Weinrich joined Conair in 2011 and is now general manager, extrusion sales. In his career, Weinrich was also global product manager for Xaloy and spent 14 years with Milacron as product manager. Contact: 724-584-5500; cweinrich@conairgroup.com; conairgroup.com.
A new study shows how the type and amount of LDPE in blends with LLDPE affect the processing and strength/toughness properties of blown film. Data are shown for both LDPE-rich and LLDPE-rich blends.
You rightfully worry about melt temperature, but don’t overlook head pressure, because the two are closely linked and will influence line performance.
Die buildup, also called die drool, die bleed, or plate-out, can plague any extrusion process.
If a little cooling is good, is a lot of cooling better?
Here is review of popular extrusion cutting technologies, strengths and limitations of each, and common problems and solutions.
Demand for building products is thriving, and profile extrusion houses are looking to expand capacity. The question they—and possibly you—face is to simply add more single-profile lines or “go dual.” Here’s what you need to consider.
That is the question pipe and tubing processors typically confront when they specify a line for one product, only to have to add to the product mix when business conditions change. Here are some tips to guide you to the right answer.
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Ppr Pipe Extruder Plastics Technology covers technical and business Information for Plastics Processors in Injection Molding, Extrusion, Blow Molding, Plastic Additives, Compounding, Plastic Materials, and Resin Pricing. Learn More