hydrogen storage cylinder - plastic molding 1 2

If you are processing a semi-crystalline resin, you have an entirely different situation. Semi-crystalline resins melt differently, like ice. That is, they stay hard until they reach their melting temperature. In addition, you can bring semi-crystalline resins up to their melting temperature, but they’ll stay solid, just like ice; you need to pump extra energy into them to cause melting.

Previously we have discussed the effects of temperature and time on the long-term behavior of polymers. Now let's take a look at stress.

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.

Exhibitors and presenters at the plastics show emphasized 3D printing as a complement and aid to more traditional production processes.

The actual pouring process is very straightforward. Heat up a cup of Plastisol in a microwave until it has turned from liquid to molten plastic. I do this in 1.5 – 2 minute intervals, stirring in-between. Once I get the plastic to the appropriate temperature I add my desired color and any glitter to the mix and stir well. I then put the mixing cup back in the microwave for another 30 seconds or so before doing one final stir and then pouring into the mold. Optimal temperature varies by Plastisol manufacturer but is somewhere between 300-400 degrees. The Plastisol will start to turn yellow if it is heated beyond its optimal range, so keep a thermometer handy to get the plastic to the correct temperature.

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.

Thousands of people visit our Supplier Guide every day to source equipment and materials. Get in front of them with a free company profile.

3. Metering section, which generally makes up 25% of the flight length (five flights). The purpose of the metering section is to pump plastic forward through the check valve, developing the pressure to counteract the back pressure to push the screw backwards to develop the shot size. The metering section is not designed to melt plastic granules. It acts as pump to develop shot size.

It is also important to cover your limbs when pouring. Even in the summer I wear a long-sleeve sweater when pouring plastics. I’ve spilled hot Plastisol on myself while wearing a sweatshirt and it still was not fun. I couldn’t imagine the pain of a direct spill on my skin. The stuff sticks like napalm so expect to get burned if it makes contact with any exposed skin. In a rare case, it could “burp” in your mixing cup. I’ve only had this happen to me once when I was mixing several different types of recycled plastics together. Always work in a well-ventilated area such as outside or in an open garage. If you are going to pour during the winter, make sure to warm the molds and mixing cups prior to pouring. If you pour hot plastic into a cold mold it could crack (especially when using plaster.) The simplest way I have found to do this is to store them indoors prior to use. Wear a respirator and safety goggles to keep the fumes produced by the plastic from getting into your eyes, nose, and mouth.

Pouring the plastic without making a major mess can be somewhat of an art. Before pouring each batch, I brush a light coat of worm oil into the mold cavities. This helps the baits release once they’ve cured. When pouring, I start at the head and work my way towards the tail. If I’m pouring two colors in one mold I pour the belly color first and then wait 30 seconds to a minute before pouring the top color. This keeps the two layers from blending together. Timing is everything when getting to the last portion of the mold, especially with a small tail that comes to a point like an eel. The more times that you pour, the less trimming there will be afterwards as you will develop a feel for when to stop.

Plastics Technology’s Tech Days is back! Every Tuesday in October, a series of five online presentations will be given by industry supplier around the following topics:  Injection Molding — New Technologies, Efficiencies Film Extrusion — New Technologies, Efficiencies Upstream/Downstream Operations Injection Molding — Sustainability Extrusion — Compounding Coming out of NPE2024, PT identified a variety of topics, technologies and trends that are driving and shaping the evolution of plastic products manufacturing — from recycling/recyclability and energy optimization to AI-based process control and automation implementation. PT Tech Days is designed to provide a robust, curated, accessible platform through which plastics professionals can explore these trends, have direct access to subject-matter experts and develop strategies for applying solutions in their operations.

Second quarter started with price hikes in PE and the four volume engineering resins, but relatively stable pricing was largely expected by the quarter’s end.

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.

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.

Multiple speakers at Molding 2023 will address the ways simulation can impact material substitution decisions, process profitability and simplification of mold design.

Discover how artifical intelligence is revolutionizing plastics processing. Hear from industry experts on the future impact of AI on your operations and envision a fully interconnected plant.

Additive technology creates air pockets in film during orientation, cutting down on the amount of resin needed while boosting opacity, mechanical properties and recyclability.

Determining the source of streaking or contamination in your molded parts is a critical step in perfecting your purging procedures ultimately saving you time and money.

So what’s the big deal about using more than 65% of the barrel capacity? You will have problems with unmelt and melt uniformity that will result in parts that do not look right or function properly. As the screw turns and backs up to make the shot, the feed section of the screw actually becomes shorter, from the point of view of the pellets (see Fig. 2). With large shot sizes, a good portion of the feed section winds up behind the feed throat, and there are only a few flights at most to prepare the granules for the transition or compression zone.

Join this webinar to explore the transformative benefits of retrofitting your existing injection molding machines (IMMs). Engel will guide you through upgrading your equipment to enhance monitoring, control and adaptability — all while integrating digital technologies. You'll learn about the latest trends in IMM retrofitting (including Euromap interfaces and plasticizing retrofits) and discover how to future-proof your machines for a competitive edge. With insights from industry experts, it'll walk you through the decision-making process, ensuring you make informed choices that drive your business forward. Agenda: Maximize the value of your current IMMs through strategic retrofitting Learn how to integrate digital technologies to enhance monitoring and control Explore the benefits of Euromap interfaces and plasticizing retrofits Understand how retrofitting can help meet new product demands and improve adaptability Discover how Engel can support your retrofitting needs, from free consultations to execution

I began pouring my own soft plastics for use in the surf, kayak and by boat several years ago. It has allowed me to get exactly what I was looking for out of a soft plastic. There are plenty of great soft plastics available on the market, but hand-pouring soft plastics allows you to connect with your fishing on a deeper level. For me, there is a great sense of pride in catching a big fish on something I’ve made myself.  Through my quest of pouring my own plastics, I’d like to thank my buddy, Gabe Ravizza of Gravity Tackle (creator of the 13.5-inch GT Eel) for the help he has given me along the way.

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.

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.

2. Transition section (also known as the compression section), which normally accounts for 25% of the flight length (five flights). The purpose of this section is to uniformly melt the plastic granules. Your shot has to be uniformly melted in these five flights. In this section, the root diameter expands, tapering to the root diameter of the metering zone. Thus, the flight depth decreases, compressing the plastic up against the barrel wall under significant pressure, which, in combination with the friction of the pellets on the barrel wall, mechanically drives enough energy into the plastic granules to melt them.

While the melting process does not provide perfect mixing, this study shows that mixing is indeed initiated during melting.

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.

So run the feed throat warm, not cold. You can also ask your most grizzled operator—I call him Old Crusty Senior—how many times he has seen the hopper blown to the ceiling to get an idea of the amount of pressure that can build up. Do not stick your face in that hopper without eye protection.

Core Technology Molding turned to Mold-Masters E-Multi auxiliary injection unit to help it win a job and dramatically change its process.

Sustainability continues to dominate new additives technology, but upping performance is also evident. Most of the new additives have been targeted to commodity resins and particularly polyolefins.

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.

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.

Driven by brand owner demands and new worldwide legislation, the entire supply chain is working toward the shift to circularity, with some evidence the circular economy has already begun.

Successfully starting or restarting an injection molding machine is less about ticking boxes on a rote checklist and more about individually assessing each processing scenario and its unique variables.

This Knowledge Center provides an overview of the considerations needed to understand the purchase, operation, and maintenance of a process cooling system.

The aim of this presentation is to guide you through the factors and the numbers that will help you determine if a robot is a smart investment for your application. Agenda:  Why are you considering automation? What problems are you trying to solve? How and why automation can help Crunch the numbers and determine the ROI

Across the show, sustainability ruled in new materials technology, from polyolefins and engineering resins to biobased materials.

Making your own mold is very easy. Just make up a casting tray either with a plastic container, baking tray, or even a cardboard box lined with aluminum foil. I have found the best way to cast a mold is to make a box out of foam board using hot glue to tack it together and lining it with aluminum foil to help with releasing the mold after it has cured. This allows me to make it just big enough for what I need so that I am not wasting extra plaster or space. The bait being casted must be held down inside the mold box otherwise it will float up when pouring the POP. This can be done with glue, double-sided tape or thin-gauge pins. You just need something that will keep the bait down inside your casting box. I have found putting a strip of double-sided carpet tape on the bottom of the mold and using thin gauge pins to help keep the bait in place while pouring works well.

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.

Join Engel in exploring the future of battery molding technology. Discover advancements in thermoplastic composites for battery housings, innovative automation solutions and the latest in large-tonnage equipment designed for e-mobility — all with a focus on cost-efficient solutions. Agenda: Learn about cutting-edge thermoplastic composites for durable, sustainable and cost-efficient battery housings Explore advanced automation concepts for efficient and scalable production See the latest large-tonnage equipment and technology innovations for e-mobility solutions

Generally 70% to 90% of the energy necessary to melt the plastic comes from this compressing, friction, and screw-rotation combination. The flights of the screw shave the melt film on the barrel wall and push it forward to the final section of the screw.

Formnext Chicago is an industrial additive manufacturing expo taking place April 8-10, 2025 at McCormick Place in Chicago, Illinois. Formnext Chicago is the second in a series of Formnext events in the U.S. being produced by Mesago Messe Frankfurt, AMT – The Association For Manufacturing Technology, and Gardner Business Media (our publisher).

In the last few months, I have seen a number of problems related to barrel capacity. I touched on calculating shot size vs. barrel capacity in the past, but it is time to review the subject and hone in on how much barrel capacity you should utilize.

In a time where sustainability is no longer just a buzzword, the food and beverage packaging industry is required to be at the forefront of this innovation. By adopting circular packaging processes and solutions, producers can meet regulatory requirements while also satisfying consumer demand and enhancing brand reputation. Join Husky to learn more about the broader implications of the circular economy — as well as how leading brands are leveraging this opportunity to reduce costs, increase design flexibility and boost product differentiation. Agenda: The cost and operational benefits of embracing circularity Key materials in circular packaging — including rPET and emerging bioplastics How to design a circular food and beverage package Strategies for selecting sustainable closures to future-proof packaging solutions Optimization and streamlining of production processes for enhanced efficiency How Husky Technologies can enable your sustainable success

Now you’ll understand why some processors see flights eroded or even completely missing when they pull screws. In addition, you can now also explain why you have unmelt in your parts. Some will argue that the metering zone will finish melting. Not so—it is merely a pump.

To get started with pouring your own plastics you’ll need some supplies and safety equipment. Outside of Plastisol, pigment, glitter, scent, worm oil and a mold you will need the following equipment: a microwave to heat the liquid Plastisol, a glass-measuring cup to heat the Plastisol (do not use plastic as it will crack), metal mixing spoons (do not use wood, they add moisture and create bubbles), leather gloves, a respirator, safety goggles, and a well ventilated workspace. You want to make sure you dedicate a microwave to pouring plastics; do not use a microwave that is also used to cook food.

As the screw turns and backs up to make the shot, the feed section of the screw actually becomes shorter from the point of view of the pellets. As a result, the material is not being adequately prepared for the transition section, which is where it melts.

While the molds are cooling, I start getting my next batch of plastic ready. Usually by the time I’m ready to pour again, the first set of baits are ready to be pulled from the mold. I let them sit upright for a day or two before taking them fishing so that they retain their proper shape. After the baits sit, I soak them in scented worm oil to make them even more enticing to the fish. My go-to scent is shad, even in eel baits, as it produces the best results of the several scents I’ve tried. You can also add salt or other additives to your mix to increase weight and adjust buoyancy. Pouring is a great way to pass time during the off-season when cabin fever sets in, just be sure to take safety precautions and wear the appropriate safety equipment.

Processors with sustainability goals or mandates have a number of ways to reach their goals. Biopolymers are among them.

There are several different materials used for open-pour molds. Plaster, resin, silicone and aluminum tend to be the four most common mold materials. Many shapes of molds for both fresh and saltwater plastics are readily available in both silicone and aluminum. An online search can yield many different molds available to purchase, but I wanted something different so I make my own molds by casting the desired bait I wish to make. I’ve casted molds with both plaster of Paris and fiberglass resin. Plaster is easier to mold but takes more time to produce since you must seal it. Resin is more difficult to use but once it is cured, the mold is ready to go.

When, how, what and why to automate — leading robotics suppliers and forward-thinking moldmakers will share their insights on automating manufacturing at collocated event.

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.

Join KraussMaffei for an insightful webinar designed for industry professionals, engineers and anyone interested in the manufacturing processes of PVC pipes. This session will provide a comprehensive understanding of the technology behind the production of high-quality PVC pipes: from raw material preparation to final product testing. Agenda: Introduction to PVC extrusion: overview of the basic principles of PVC pipe extrusion — including the process of melting and shaping PVC resin into pipe forms Equipment and machinery: detailed explanation of the key equipment involved — such as extruders, dies and cooling systems — and their roles in the extrusion process Process parameters: insight into the critical process parameters like temperature, pressure and cooling rates that influence the quality and consistency of the final PVC pipes Energy efficiency: examination of ways to save material and energy use when extruding PVC pipe products

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.

Join Wittmann for an engaging webinar on the transformative impact of manufacturing execution systems (MES) in the plastic injection molding industry. Discover how MES enhances production efficiency, quality control and real-time monitoring while also reducing downtime. It will explore the integration of MES with existing systems, emphasizing compliance and traceability for automotive and medical sectors. Learn about the latest advancements in IoT and AI technologies and how they drive innovation and continuous improvement in MES. Agenda: Overview of MES benefits What is MES? Definition, role and brief history Historical perspective and evolution Longevity and analytics Connectivity: importance, standards and integration Advantages of MES: efficiency, real-time data, traceability and cost savings Emerging technologies: IoT and AI in MES

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.

In that column, I stated that your process should take somewhere between 25% and 75% of the barrel or shot capacity. Today, the maximum I recommend is 65%. This may seem a bit odd. Consider a barrel with 230 mm (10 in.) of stroke; why not use it all? What is wrong with using 80% or more (~180 mm or 8 in.)? If you do, you are inviting Murphy to the party, and he will bring along his friends. The reason has to do with how the screw works and the type of resin you are processing—amorphous or semi-crystalline. First, let’s review the basic components and their function for a 20:1 L/D general- purpose (GP) screw. Typically screws have three sections (see Fig. 1):

Two points to remember here: First, the feed section does not melt the plastic granules; second, the air that enters with the granules needs to be vented out the feedthroat. The feedthroat must be warm enough to allow the air and volatiles coming off the resin to reach the atmosphere. If it’s too cold you will condense some of these volatiles inside the barrel. But if you have this section of the barrel too hot, you can develop a melt film between the flights and the barrel wall, which traps the air/volatiles and prevents them from venting, which causes splay or bubbles in your parts.

ABOUT THE AUTHOR: John Bozzelli is the founder of Injection Molding Solutions (Scientific Molding) in Midland, Mich., a provider of training and consulting services to injection molders, including LIMS, and other specialties. Contact john@scientificmolding.com; scientificmolding.com.

The Plastics Industry Association (PLASTICS) has released final figures for NPE2024: The Plastics Show (May 6-10; Orlando) that officially make it the largest ever NPE in several key metrics.

While prices moved up for three of the five commodity resins, there was potential for a flat trajectory for the rest of the third quarter.

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.

While the major correction in PP prices was finally underway, generally stable pricing was anticipated for the other four commodity resins.

From crafting molds, to blending unique custom colors, pouring soft plastics is a rewarding way to pass the winter months.

Plastics Technology covers technical and business Information for Plastics Processors in Injection Molding, Extrusion, Blow Molding, Plastic Additives, Compounding, Plastic Materials, and Resin Pricing. About Us

Despite price increase nominations going into second quarter, it appeared there was potential for generally flat pricing with the exception of a major downward correction for PP.

For the DIY pourer, plaster of Paris (POP) is a great place to start for making your own mold as it is affordable and easy to cast with. The downside of plaster is that is must be sealed and fully dried out before sealing. Many pourers use Modge Podge to coat their POP mold, but my findings were that I would have to wait too long between pours to let it cool down otherwise the glue would lift from the mold. I ended up using a high-temp-rated epoxy to seal my POP molds. It required more work initially to seal, but ultimately produces a smoother product and allows more use out of the mold.

Why is this a problem? The feed section is only meant to feed, not melt the granules. But it also provides some heat transfer, and by effectively shortening the feed section you are not adequately preparing the granules for the transition zone. You may get by if you’re molding amorphous resins, as they melt like butter. They can soften before getting up to their melt temperature, so they are easier for the transition zone to handle. But you are still asking for unmelt.

This is called the latent heat of crystallization. Basically it is an energy barrier, and it can cause severe problems in melting and screw wear. Most semi-crystalline resins not only do not soften but require nearly twice the BTUs (energy) to melt. For example, amorphous ABS takes about 150 BTU/lb to bring it from room temperature to melting. The same amount of polyethylene will take about 350 BTU/lb. Also, factor in the short time your cycle leaves to melt this plastic.

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.

Say “manufacturing automation” and thoughts immediately go to the shop floor and specialized production equipment, robotics and material handling systems. But there is another realm of possible automation — the front office.

I start by pouring my plaster of Paris mixture around the baits, then on top of them. Make sure to shake any air bubbles out of the mold before it sets up. Once it has cured you can pull the mold from the casting box, flip it upside-down and pull the baits out. Before sealing the mold, it must be fully dried. You can do this by leaving it in a dry place for a week or putting it in the oven at around 200* for 2 hours. Don’t let it get to hot or stay in for too long as it could crumble. After the mold has fully dried, I coat it with a high-temp epoxy. The epoxy coating gives the mold a smooth feel allowing the poured baits to release easily and give them a glossy look.

Ultradent's entry of its Umbrella cheek retractor took home the awards for Technical Sophistication and Achievement in Economics and Efficiency at PTXPO.

1. Feed section, which comprises normally 50% of the flight length (10 flights). The purpose of this section is to feed the material to the transition zone, not melt it. It starts the melting process by com- pressing the granules together, which pushes the air that enters the deep flights back out the feedthroat. Also, it transfers some energy (heat) to the granules, prepping them for the transition zone.

Plastics processors are finding applications for 3D printing around the plant and across the supply chain. Here are 8 examples to look for at NPE2024.

This month’s resin pricing report includes PT’s quarterly check-in on select engineering resins, including nylon 6 and 66.

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.

While prices moved up for three of the five commodity resins, there was potential for a flat trajectory for the rest of the third quarter.

Across all process types, sustainability was a big theme at NPE2024. But there was plenty to see in automation and artificial intelligence as well.

When it comes to choosing a liquid Plastisol, the number of options available is overwhelming. I started off by buying a gallon of MF Plastic’s Regular Plastisol based on what Mark was using. Since then, I’ve tried several different brands of plastisol with my favorite being Bait Plastic’s #212 Medium. Plastisol is typically available in soft, medium, and hard (also known as saltwater from many brands.) You can also purchase blends such as soft/medium or medium/hard. The softer the plastic, the more action it will have but the quicker it will tear off the hook. I like a medium plastic because it gives me great action at a reasonable level of durability. Try different Plastisols and use what you are most comfortable with or what produces your desired results. Many are available in quart size containers that make a great trial size before settling on a specific brand. I’ve noticed slight characteristic differences between the major brands of Plastisol. My overall experience with the Bait Plastic’s product has been great.