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. 3d Printed Mold Inserts
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.
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
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.
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.
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.
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.
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.
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.
Three-plate molds have significantly more design considerations that affect their cost, functionality and longevity. That’s why it is especially important to pay attention to every detail, as well as having a thorough and collaborative mold design review.
What is the mold going to make? Is it a one-cavity flower pot or 128-cavity syringes? Or is it something in between? When it comes to three-plate molds, or any mold for that matter, it’s not what the mold is going to make. It’s how many cycles are expected over the course of the mold’s life span. That’s what dictates how a mold should be designed and built. It may need a little more attention to the details and a little more initial cost to be profitable in the long run. Details can help avoid machine downtime and higher maintenance costs. They also help to keep the customer happy and foster the chances of future business.
FIG 1 A T-Series mold base. Images: J. Fattori
The type of mold base specifically designed for three-plate molds is called a T-Series mold base, as shown in Fig. 1. A T-Series mold base is similar to an A-Series mold base, but with an additional plate between the Injection Clamp Plate and the A-Plate. This extra plate is called the X-1 plate or, more commonly, the Runner Stripper Plate. A three-plate mold has a minimum of three parting lines, but no maximum number.
The primary advantages for using a three-plate mold are central gating, multiple gates feeding a single part, multiple gates feeding multiple parts, or even multiple gates feeding multiple parts and runners. Three-plate molds often eliminate the need for an expensive hot runner system. Other advantages include automatic degating and separation of the cold runner from the parts. Because the runner system is machined into a separate parting line, the cavities and cores can also be spaced closer together.
Three-plate molds have significantly more design considerations.
In most cases, the projected area of the runner does not need to be included when calculating the amount of clamp tonnage required. Some of the disadvantages are higher mold cost, higher maintenance costs, heavier cold runner, longer cycle times, longer material flow lengths, longer mold opening stroke, and difficulty removing both the parts and the runner robotically.
The best place to start is to talk about designs using a standard sprue bushing. Fig 2 shows a straight sprue bushing. This design will most likely start to gall in a very short amount of time. Fig. 2a shows the same sprue bushing, but with a taper added to the tip, which seats against a tapered bore hole in the floating runner stripper plate. The taper is obviously added to prevent galling.
The design in Fig. 2a should only be used for prototypes or extremely low production quantities. The design in Fig. 2 can be used for low- to medium-production quantities. Using a standard sprue bushing has two very serious design flaws. First, it requires the parting line opening between the runner stripper plate and the A-plate to be much longer, which can require a larger and more expensive molding machine with a greater opening stroke. Second, the cold sprue will more than likely hang up in the runner stripper plate, requiring it to be manually or robotically removed.
FIG 2a: Tapered sprue bushing.
The preferred design is to use a commercially available extended sprue bushing with a mating runner stripper plate bushing, as shown in Fig. 3. In my opinion, the standard sprue bushing shouldn’t even be an option for molders. All T-Series mold bases should be supplied with an extended sprue bushing and runner stripper plate bushing. They save material, potentially reduce the cycle time and eliminate the need for a much longer mold opening stroke.
Depending on the thickness of the runner stripper plate, you could have a minor issue that needs to be considered. Because the runner stripper plate bushing is only commercially available in 7/8 in. thickness, there’s a good chance of galling of the extended sprue bushing if the runner stripper plate is 1-3/8 in. or thicker, as shown in Fig. 4. This is easy enough to correct by adding a little clearance between the plate and the outside diameter of the extended sprue bushing.
FIG 3 Extended sprue bushing and runner stripper-plate bushing.
If the mold design allows, I like to use the extended sprue bushings that have the larger 3-1/4 in. inside diameter, as shown on the right side of Fig. 5. You can run into issues on the production floor if the machine’s nozzle body with its attached heater bands and thermocouple can’t fit into the bushing without ripping the wires off. Note: The extended bushing with the larger recess may require a thicker injection clamp plate, which is often beneficial.
The cavities can usually be closer together in a three-plate mold.
While the dimensions for the extended sprue bushing and stripper plate bushing are very similar among mold component suppliers, their material types and hardness values vary widely. You would be wise to match the physical properties of these components with the intended life span of the mold. Softer components can wear out faster due to trapped dirt, debris and plastic flakes. They can also hob from flash on the runner, as well as nozzle drool and stringing.
FIG 4 Galled extended sprue bushing.
The runner stripper plate bushing typically has an outside diameter of 2.750 in., but the tolerance is ± who knows what. If the fit of the bushing in the runner stripper plate isn’t a slip fit or tighter, it can result in down-flash, especially when the molding material is a low-viscosity resin, such as nylon. Down-flash can cause the runner to hang onto the runner stripper plate, instead of falling freely out of the mold.
There are only two acceptable types of runner types for a three-plate mold — trapezoidal and parabolic — as shown in Fig. 6. Parabolic is the preferred type because it uses slightly less material and will solidify slightly faster. It has slightly less cross-sectional area and the surface area is more uniform.
Other than having to be trapezoidal or parabolic, the runner in a three-plate mold has basically the same requirements as any type of runner in a two-plate mold. It should have a cold well opposite the extended sprue bushing the gate, as shown in Fig. 7. Granted, the cold well for a three-plate mold will have a much different shape than that of a two-plate, but it serves the same purpose: to catch any solidified material in the molding machine’s nozzle tip, preventing it from flowing down a runner channel and blocking a gate or leaving aesthetic marks on the part.
FIG 5 Small- and large-bore extended sprue bushings.
Despite most people’s belief, a runner overflow does not need to be added to the end of every runner branch. It has been proven that the cold well opposite a sprue bushing is so effective, one more overflow further down the melt flow channel, as shown in Fig. 8, is basically just insurance, because they also work extremely well. Any additional overflows will be a waste of material.
Three-plate molds need cold wells opposite the sprue.
Most people also believe you need to add a vent at the end of every runner branch. I am not sure I completely agree about adding vents to any portion of a runner system, no matter if it is a two-plate or three-plate mold. The purpose of a vent is to enable the air and gases to escape before entering the cavity. It seems logical to me that the air inside a runner system is going to take the path of least resistance and go through the relatively large gate orifice before it will go through a vent that’s only a thousandth or two deep.
FIG 6 Acceptable three-plate mold-runner types.
The only scenario I can think of where venting the runner would be beneficial is when the gate(s) were very small and the injection velocity was extremely fast. In that scenario, it may be possible for a significant positive pressure to build up inside the runner system, which would force some of the air to escape through a vent before it is skinned over with material, preventing any additional air from escaping. It certainly can’t hurt to add vents to the runner, but I’d sure like to see someone write their thesis on it, backed with empirical data.
If the mold has multiple cavities of different parts, there is no reason why a runner turn-off (RTO) can’t be used, just like in a two-plate mold. In fact, it’s easier to install an RTO in a three-plate mold because you only need them on one side.
FIG 7 Three plate cold well opposite the sprue gate.
Obviously, the runner layout should always be geometrically or “naturally” balanced. Family molds can be extremely difficult to balance. The goal in balancing a family mold is to have all the parts finish filling at the same time — not necessarily start to fill at the same time. The primary reason why you want all of the parts to finish filling at the same time is so they all receive the same amount of packing pressure. If they don’t, you waste material by overpacking some cavities, which make them heavier.
Another reason is that cavities that are under-packed or overpacked will have dimensional issues because they will have a different shrinkage factor than what was used to machine the mold. The trick to adjusting a family mold is to adjust the flow rate of the material in the runners feeding each cavity. Changing the gate depth or width only changes the fill speed going through the gate. It does not change the volumetric flow rate (in.3/sec). Therefore, to correctly balance family molds, you need to change the runner flow area to each cavity.
There is an advantage to incorporating a runner bar in three-plate family molds.
I was taught decades ago that runners should be cut into a hardened insert, called a runner bar, especially if the material was abrasive. I was also taught that the runner should be highly polished to reduce the injection pressure. Fellow Plastics Technology columnist John Bozzelli showed me that because material flows like a fountain within the mold, there was no need for a hardened insert or a high polish.
However, there is an advantage to incorporating a runner bar in three-plate family molds. Because any required size adjustments to the runner need to be made, they can be made faster and easier with a removable insert instead of the entire plate. Additionally, the runner can be affordably made of a different material, such as a thermally-conductive material for faster cycle times.
Just like a two-plate mold, radiused runner turns are preferred over 90° bends, especially for shear-sensitive or glass-filled materials. If you do have any 90° bends, the inside corners should have their sharp edges blended to help reduce the stress on the material. It will also help prevent the runner from potentially cracking upon ejection.
FIG 8 Cold wells are highly effective at trapping cold slugs.
Some runner layouts can have a heavy mass at branch intersections. These can often be cored out, just like you would with a two-plate mold, without affecting the material flow or pressure.
It may not be a bad idea to engrave the corresponding cavity numbers on the runner, as shown in Fig. 9. It makes it a little more foolproof when adjusting the runner flow areas. The engraving should be made in the A-plate. If it is engraved in the runner stripper plate, make sure there’s sufficient taper. Even a shallow engraving can cause the runner to hang up.
Three-plate molds often have longer cycle times than two-plate molds. This is due to the size of the runner. A flow analysis is a good investment for three-plate molds. Molders are often amazed at how small a runner can be made, as predicted by a flow analysis. A flow analysis can help minimize the amount of regrind and injection pressure loss, as well as the cycle time. If a mold flow analysis is not practical, the runners, drops and gates can be intentionally machined undersized. The pressure drop through the runner (and the gate) can be determined at the first sampling by conducting a scientific molding pressure loss study and the runners, drops and gates subsequently enlarged if necessary.
FIG 9 Cavity number engraved on the runner.
If the runner is to be extracted with a robot or a picker, you want the runner to be “free” but not fall out of the mold. You can add a molded pin in the runner stripper plate to hold the runner in position for the robot to grab, as shown in Fig. 10. The robot’s “strip-stroke” will pull the pin out of the runner stripper plate.
FIG 10 Three-plate runner with a molded pin for robotic extraction.
About the Author: Jim Fattori is a third-generation injection molder with more than 45 years of molding experience. He is the founder of Injection Mold Consulting LLC. Contact jim@injectionmoldconsulting.com; injectionmoldconsulting.com.
Most molders work with two parameters for establishing second-stage pressure. But within Scientific Molding there are actually four.
Of all the gate types, tunnel gates are the most misunderstood. Here’s what you need to know to choose the best design for your application.
First find out if they are the result of trapped gas or a vacuum void. Then follow these steps to get rid of them.
Flashing of a part can occur for several reasons—from variations in the process or material to tooling trouble.
Implementing a production monitoring system as the foundation of a ‘smart factory’ is about integrating people with new technology as much as it is about integrating machines and computers. Here are tips from a company that has gone through the process.
At captive processor McConkey, a new generation of artificial intelligence models, highlighted by ChatGPT, is helping it wade through the shortage of skilled labor and keep its production lines churning out good parts.
Coverage of single-use plastics can be both misleading and demoralizing. Here are 10 tips for changing the perception of the plastics industry at your company and in your community.
Molding Gate Design 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