In-Mold Electronics: Short-Term Pain, Long-Term Gain? - short mold in injection/In-Mold Electronics: Short-Term Pain, Long-Term Gain?

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In-Mold Electronics: Short-Term Pain, Long-Term Gain? - short mold in injection

Author：gly Date: 2024-09-30

While it’s true that heat-treated tool steels with high compressive strength can delay the amount or severity of flash damage, it cannot make the mold impervious to damage. Figure 4 shows a severely hobbed parting line of a pre-hardened 28-32 Rockwell C mold caused by nozzle strings. Generally speaking, the harder the tool steel is, the more brittle it is. Obviously, there is a tradeoff when it comes to the physical properties of metals. Depending on several factors, you might need to consider using a more ductile material, or making a spare cavity set as insurance.

In addition, careful selection of color concentrate carriers is needed to ensure good TPE adhesion to nylons. In general, LDPE and EVA are preferred carriers with nylon substrates.

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

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

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

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.

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.

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.

Moreover, thickness of the TPE layer also affects adhesion strength. Thin TPE layers tend to surrender heat rapidly in the cold cavity, and the drop in temperature tends to reduce bonding strength. The challenge for the designer is to strike a balance between the durometer and thickness of the TPE to achieve the cushioning level desired.

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.

A very common cause of mold damage is due to galling. When two pieces of steel rub or slide against each other, there is a risk of them metallurgically bonding together. You can usually hear the components squeaking shortly before they seize up. Galling can occur at any time—from the initial mold sampling up to 1 million cycles later. Everyone from the machine operator to the plant manager should be aware of what this sound means. Recognizing a galling situation early can reduce the amount of mold damage.

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.

These humble but essential fasteners used in injection molds are known by various names and used for a number of purposes.

Preheating inserts prior to overmolding often improves adhesion strength. The extent of improvement depends on the degree of compatibility between insert material and TPE. The appropriate insert temperature depends on the substrate and TPE and is best determined through discussions with the materials suppliers.

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

Just like an airplane, car, boat or motorcycle, a mold can potentially last forever if it is maintained properly and repaired when necessary. The only time a mold is considered unusable or has reached the end of its lifespan is when the repair cost exceeds its worth. In addition to the part and mold complexity, the mold’s longevity is based on many other factors, including (but not limited to) the mold design, steel selection, quality of the mold components and construction, the molding machine it runs in, molding material type and molding process used to make the parts, as well as the mold installation, removal, maintenance and storage.

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.

Compounders face a number of processing challenges when incorporating a high loading of low-bulk-density mineral filler into polyolefins. Here are some possible solutions.

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.

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

The hardness of the plastic, as well as the hardness of the mold can dictate how quickly and how severely the mold will get damaged. If a hot bushing is drooling Ultem PEI in a P-20 mold, it won’t be long before you are grinding a few thousandths off the parting line to clean it up. I know moldmakers that intentionally make the mold cores 0.005 in. taller because they believe they will be grinding the parting line a couple of times over the life of the mold. But the hardnesses of the plastic and the steel are not the only factors that promote flash. The list of potential causes is exhaustingly long. Here are some of the more common ones:

5. Is there a target price for the molded part? This is a common question for thin-walled and commodity parts, such as caps and closures, where cycle time is critical and the need for a hot-runner system is paramount. High-thermal-conductivity materials such as copper alloys may be required. Unfortunately, too few moldmakers ask this question—unless they are also going to be the molder.

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

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.

With advocacy, communication and sustainability as three main pillars, Seaholm leads a trade association to NPE that ‘is more active today than we have ever been.’

• Ejection efficiency: Part ejection can be facilitated by designing 0.5° to 1° of draft into each side of the mold. With more ejection-resistant materials like TPUs, a 5° to 6° draft is sometimes required. Texturing the tool surface frequently improves ejection, whereas a more polished surface tends to impair it.

Adhesion is not the only important consideration in overmolding, so here is some advice on aspects of tool design that will optimize other areas of performance:

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.

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.

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

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

Toughness, which is basically a combination of strength and ductility, is important for tall, free-standing cores, as well as cavities with sharp inside corners where cracking from molding pressures is a concern. H-13 has very good toughness properties. S-7 is also good.

If the material is highly abrasive, such as those with glass fillers, all the surfaces in contact with the plastic need to be through-hardened—the harder the better. That includes the sprue bushing and runner inserts, not just the cavities and cores. Abrasive materials can also dictate that the gate(s) be inserted because they will be the first thing(s) to wear out. Steels with high concentrations of carbon and chrome typically have good wear resistance. If the material is extremely abrasive, such as a thermally conductive material with silicon carbide filler, then one of the powdered-metal tool steels with a typical hardness value of about 60 Rockwell C could be best suited.

In recent years, however, the range of materials used in overmolding has expanded significantly to include more TPE classes (e.g, TPU, TPV, SEBS) and a broader range of substrates (ABS, PC, and nylon). While the broader materials spectrum for overmolding expands opportunities for soft-touch design, it also adds new levels of complexity and poses new challenges in adhesion.

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.

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.

I have already mentioned polishability, thermal conductivity, hardness and corrosion resistance. But what about toughness, compressive strength, wear and abrasion resistance? These are important properties to consider as well, especially when two pieces of steel slide against each other, like a cam, lifter or shutoff. The old rule of thumb says that if different steel types are used and there is a 10-point Rockwell C differential between them, everything will be fine. That rule of thumb doesn’t always hold true—especially if the forces are high and the contact area is large. O-6 and A-10 steels are good for sliding applications because these two steels have high concentrations of graphitic particles in their microstructure. O-1, O-2, D-2 and S-1 are also good steel types for sliding applications.

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

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

In a few cases (e.g., parts with exceptionally long flow paths or highly wear-prone areas), features are designed into the substrate to create a mechanical interlock after overmolding with TPE.

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.

The real mold killer—for any mold, of any complexity—is parting-line flash. When plastic or other debris adheres to the parting line of a mold, it can deform the mold by leaving an impression or indentation. If you think about it, when debris is sandwiched between two flat surfaces and is exposed to a few hundred tons of clamp pressure, it has nowhere to go but in.

For example, if a part design has sharp outside corners (meaning sharp inside corners in the mold) and is subjected to high injection pressures, it’s longevity could be very short due to the potential of fracturing. I’ve seen well-built, class 101 hot-runner molds fail after the first five minutes because the manifold filled up with plastic—snapping bolts and splitting plates apart. I have also seen dead-soft aluminum molds run trouble-free for well over a decade.

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

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.

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.

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.

• Surface texture: Designers are sometimes tempted to underscore the texture and grip properties of a TPE by polishing the mold to add a smooth finish. Yet a smooth finish sometimes actually highlights flaws like knit lines and blemishes in the part. Conversely, texturing of part surfaces is often effective in hiding flaws and imparting a “grippy” or leather-like feel. Certain textures have the effect of imparting a harder or softer feel than might be anticipated in light of the TPE’s Shore A durometer. The goal is to balance the surface texture and durometer values of the TPE to get the intended product feel.

I have a 1982 edition of the Classifications of Injection Molds for Thermoplastic Materials by the Society of the Plastics Industry (now the Plastics Industry Association, or PLASTICS). My edition defines the construction requirements for various types of molds for machines up to 400 tons and labels them type 101 through 105. It also has three types of quick-change mold inserts, which are labeled type I through III. It specifies similar classifications for molds that require machines with 400 tons or more of clamp pressure. Each type has a specific number of cycles a mold is capable of producing. Table 1 summarizes these classifications and lifespan quantities.

Multi-shot molding requires a special press with multiple barrels that allow several materials to be shot into the same mold. (Most often, such parts use two-shot molding, but some parts require three or four shots.) Benefits are reduced overall production time, superior part quality, and lower labor requirements. The approach is economically viable in programs of 250,000 parts/yr or more and regions where labor costs are high.

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.

• Vent design: Air entrapment in the cavity during TPE overmolding is also detrimental to adhesion and is best addressed by adequate venting in the tool. Insufficient venting can show up as poor adhesion at the end-of-flow points, scorching of the TPE, or even short shots. Typical vent depths are between 0.0005 and 0.001 in. The right vent depth for a given part depends partly on the flow properties of the TPE involved.

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

4. Is there a dimensioned 2D drawing of the part? I have seen too many jobs quoted strictly based on a 3D CAD model. CAD models do not specify the tolerances for critical dimensions. Nor do they specify the surface finish, aesthetic areas that cannot have gate or ejector-pin marks, secondary operations, mating parts, etc. 2D drawings almost always help the moldmaker decide the best way to design and build a mold—or if the part is even moldable to the stated specifications.

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.

Figure 1 shows a cavity set for a toy soldier. It was made in 1955 by hobbing blocks of copper. Hobbing is a manufacturing method rarely used today. Non-alloyed copper is also rarely used today because it is extremely soft. The figurine in Fig. 2 (left) was originally molded out of PS. The figurine in Fig. 2 (right) was cast out of liquid silicone material a few weeks ago on my desk. There’s a little flash on the cast part, but the “clamp pressure” was only about 10 lb—generated by a few rubber bands. The point is that part geometry is where it all begins, and oftentimes, defines when it all ends.

One solution is to incorporate a “step” in the substrate profile to create an abrupt transition between TPE and substrate (Fig. 1B). Alternatively, the substrate might include an indentation, with the shut-off designed to put the TPE flush against the substrate (Fig. 1C). Both approaches reduce feathering, neutralize curling, and eliminate tear points that might initiate fraying.

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.

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.

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.

• Inferior mold design • Inferior mold construction • Insufficient mold-plate thicknesses • Insufficient support-pillar area • Lack of parting-line relief • Improper mold setup • Insufficient clamp pressure • Excessive clamp pressure • Cavity imbalance • Poor processing parameters • Excessive injection or pack pressures • Low material viscosity • Insufficient venting • Excessive vent depth • Using adhesive labels as vents • Machine bushing wear • Machine platen wear • Lack of alignment • Worn shutoffs • Abrasive molding material • Abrasive material fillers • Nozzle stringing • Sub-gate flaking • Sticking parts or runners • Rust or corrosion • Lack of preventive maintenance

Let’s do some simple math. Assume a sub-gated part leaves 1/16-in. diam. flakes on the parting line. A 1/16-in. diam. flake has an area of 0.0031 in.2. The mold is in a 500-ton press. Pressure = Force ÷ Area so in this case:

A moldmaker’s objective is to maximize the performance of a mold to achieve the lowest possible total cost per part based on the intended lifespan of the project. That analysis should include the goal of minimizing the cost to maintain the mold. Therefore, when reviewing a new project, moldmakers will wisely ask:

The thickness of the molded part is important when it comes to selecting the best material out of which to make the cavities and cores. If the part is thin-walled, selecting a material with extremely high thermal conductivity may not be the best choice. The material can solidify too quickly during injection, and you can end up with a lot of short shots or injection pressures that exceed the machine’s capabilities. Conversely, if the part is extremely thick, the thermal conductivity of the cavity and core material is not nearly as important because the molded part forms an exterior skin, which acts as an insulating barrier. That’s why a graph of cooling time vs. wall thickness is not a straight line. It is an upwardly projecting curve.

• Shut-off design: Design of the transition, or shut-off, area between the TPE and substrate is critical to adhesion. Designs should avoid “feathering,” or gradual thinning of the overmolded TPE. Thin layers cause inadequate bonding and can result in curling or fraying of the TPE layer at the tapered edges (see Fig. 1A).

• Substrate preparation: Proper preparation and handling of inserts is critical to adhesion performance. The cleaner the insert, the better the bond. The optimal production method is to overmold inserts directly after they are produced, since that minimizes chances of contaminants collecting on the insert surface. If storing inserts is unavoidable, they should be scrupulously protected against dust or dirt. Those who handle inserts should wear gloves, since skin oil can impair adhesion. Also, mold releases are best avoided since they seriously impair bond strength between TPE and substrate.

Supposedly, the classifications were updated back in 1996. More recently, there was an article in the August 19, 2021, edition of Plastics News mentioning that these standards are once again in the process of being updated by a team of industry leaders, association members and select members of the American Mold Builders Association. We should applaud their efforts to further improve this important document.

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

To properly understand the differences in performance between PET and PBT we need to compare apples to apples—the semi-crystalline forms of each polymer.

Another problem is the broad array of available nylons, which differ by resin class (e.g., nylon 6, 66, and 12), reinforcement type and loading, and additives used. In the case of a first-generation TPE, test data show that a dramatic loss of adhesion strength occurs when it is bonded to impact-modified and heat-stabilized nylon 6 (Fig. 4). But progress is being made: Data show that a second-generation, improved-adhesion grade of the same TPE class yields significantly improved adhesion performance, even with heat-stabilized products.

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

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

If the injection or packing pressure is excessive, or if the clamp pressure is insufficient, the plastic will try to ooze out of the cavity. This usually results in the sharp-edged perimeter of the cavity starting to look like someone added a small radius to it. Over time, the cavity will have more and more flash growing around it. The problem with flash is that once the surface of a mold is indented, it never gets better. It can only get worse. It needs to be repaired and the root cause determined and corrected when it’s first noticed. Giving an operator a razor blade or some other tool to remove the flash is not an appropriate corrective action.

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.

There are many factors that determine the longevity of a mold. Part complexity, which dictates mold complexity, is probably the biggest factor. A mold that produces a flowerpot, 5-gal bucket or a Frisbee can last a very long time. But more complex molds, such as those with cam action, unscrewing mechanisms, collapsible cores, contoured parting lines, sliding shutoffs, etc., will not last nearly as long because there are more component parts that can wear, break, gall, or seize. Just because a mold is made of heat-treated tool steel doesn’t mean it’s going to pump out hundreds of thousands of parts.

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.

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.

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

Some of the common causes for a mold’s decreased longevity are due to accidents on the production floor. The folks in the trenches describe such events as “crashes.” One of the most common crashes involves a cam that is out of position—usually after cleaning the parting line or removing a part, or simply because the cam retention device was too weak, and the cam slid out of position. When a cam is out of position, the angle pin does not line up with the hole in the cam and then—crash—it snaps like a twig. If the angle pin hits the top of the cam, it’s usually not a big deal. Simply replace the pin. But if it hits any cavity impression, that’s going to end the production run and cost a lot more to repair. Another common type of crash is handling a mold with one eyebolt and no safety strap. An unsecured mold half can easily hit the ground well before you can yell “Look out!”

Additional considerations also make nylon adhesion more difficult. One is their propensity for high moisture pick-up, which makes careful drying imperative. And the melt temperatures of nylons are higher than for most other substrates, so the TPE melt temperature has to be increased accordingly to ensure good bonding. Preheating of nylon inserts is also generally advised.

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.

Swedish compounders HEXPOL TPE AB and Polykemi AB have collaborated on a 2K sustainable development project for consumer products.

In selecting a gating method, it is advisable to begin with a “steel-safe” design of the gates and to size them initially on the small side, enlarging them later as required. Certain TPEs (like SEBS) require a smaller gate to boost shear and ensure complete mold fill. Other TPEs (TPVs and TPUs) generally require larger-than-normal gates to compensate for their high melt viscosity.

Crisp finish lines between the opaque TPE skin and clear PC substrate are essential in this computer lap station, both for appearance and strong adhesion.

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

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

Over the past decade, soft-touch overmolding has radically changed the look, feel, and function of a broad range of consumer products. Abundant new color, texture, and tactile options are available in such products as toothbrushes, razors, power tools, cameras, kitchen items, hand-held electronics, and auto-interior parts.

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.

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

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.

Wear and galling explain why there has been a lot of attention given to various surface coatings and surface treatments, as well as the metallurgical compatibility of different types of mating steels.

The only time a mold is considered unusable or has reached the end of its lifespan is when the repair cost exceeds its worth.

• Predrying: Some TPE types—including TPU, TPV, and copolyesters—tend to be hygroscopic, or prone to moisture pick-up. If not appropriately dried prior to molding, absorbed moisture can turn to steam and harm adhesion at the interface of the two materials. Moisture also can hydrolyze some resins, harm surface properties, and increase ejection difficulty. Moisture at the time of molding generally should not exceed 0.05% by volume. Common practice is to dry TPEs in a desiccant dryer with a –40 F dewpoint.

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.

A pre-hardened stainless-steel mold base is an even better solution. The thermal conductivity of stainless isn’t as good, but it usually doesn’t matter for a mold base. I always wondered about moldmakers who prefer steel types that have good weldability. While that is a good property to have, it shouldn’t be a guiding factor. Some steel preferences are based on years of experience. Some are based on how easy they are to machine, or how much they change size or warp during heat treatment. Usually, the commonly used steels are more than adequate for most parts. But occasionally the properties of the steel should be given greater consideration.

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.

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.

Acknowledgement: I want to thank Brenda Clark of Hasco America; Patricia Miller of Uddeholm; Roy Glenn, retired mold builder and designer; and Rick DeBeer, retired from LyondellBasell, for their knowledge and insight, which helped me compose this article.

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

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

2. What is the part used for? If it’s a medical, optical or automotive part, there’s a very good chance that the mold is required to be made of ESR (electroslag reduction) stainless steel for cleanroom conditions and optical polishing or mold texturing.

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.

• TPE melt temperature: The relationship between temperature of the TPE melt and adhesion strength is reflected in the example of a 65 Shore A TPE overmolded on a PC substrate (Fig. 2). As the melt temperature increases from 370 F to 400 F, a notable improvement in adhesion strength is evident. But a further increase to 430 F actually reduces adhesion strength. In this instance, the optimum melt temperature is somewhat less than 400 F. Molders must balance desired adhesion strength against the possible adverse effects of elevated melt temperature, e.g., thermal degradation and ejection difficulty.

• “Feel” versus thickness: The tactile feel of an overmolded part is the sum of several factors, just one being the inherent softness (Shore A durometer) of the TPE. Part feel also depends on the TPE’s coefficient of friction, texture, and—most notably—wall thickness.

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.

The best antidote is a shut-off design that creates a sharp transition between TPE and substrate. Ideally, a uniform TPE layer thickness of around 0.04 in. is desirable for good adhesion, but that is not always feasible.

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.

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

ABOUT THE AUTHOR: Jim Fattori is a third-generation molder with more than 40 years of experience in engineering and project management for custom and captive molders. He is the founder of Injection Mold Consulting LLC in Pennsylvania. Contact: jim@injectionmoldconsulting.com; injectionmoldconsulting.com

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

Driving this change is the increasingly diverse range of thermoplastic elastomer (TPE) materials. In overmolding, a TPE is injection molded over or around a compatible substrate using either insert or multi-shot processes. The resulting hard-soft structures are quite effective in comfortable, non-slip, and abrasion-resistant handles, grips, and buttons.

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.

• Concentrate carrier compatibility: Overmolding with TPEs containing color concentrates can be tricky, one danger being conflict between the colorant carrier and the TPE. The workhorse carrier for TPEs has long been PP, but this carrier frequently performs poorly when bonding certain TPE families to nylon, PC/ABS, and other engineered substrates.

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).

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

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.

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.

NPE2024: Coinjection of postconsumer resin, in-mold decoration, LSR micromolding and bioplastics processing are just some of the machine displays at Milacron's booth.

This is illustrated by adhesion data for a 55 Shore A TPE containing a color concentrate and overmolded on a PC/ABS substrate (Fig. 3). In this case, a PP concentrate carrier exhibits adverse effects on adhesion, apparently because of a conflict between the carrier and the TPE. In contrast, data show that with this particular TPE, EVA and TPU carriers provide superior adhesion.

Selecting a target melt temperature for the TPE depends on the substrate and the adhesion level required. Most TPE suppliers provide a recommended range of melt temperatures for their products. For maximum adhesion, aim towards the upper end of the supplier’s recommended range.

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.

Nylon-based materials are an increasingly popular substrate in several high-growth overmolding markets—handles and grips for power and hand tools, appliances, and lawn/garden products. The downside is that nylons are often difficult to overmold with good adhesion. TPEs bond relatively well to unmodified and glass-filled nylons, but fall short when joined to versions that are highly formulated with additive packages.

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.

In insert molding, the rigid substrate is molded first and transferred to a second mold, where a TPE is shot around the insert to create the finished part. The process uses standard injection molding machines and relatively simple, low-cost tools. Insert molding is best suited to applications involving relatively low volumes and manufacturing locations where labor costs are low.

Every customer I’ve ever had always asked how many parts their mold could make. Most moldmakers will respond to that question by saying something like, “Well, you paid for a Class 101 mold, so it should produce up to 1 million cycles.” Obviously, that answer is based on the PLASTICS mold classifications. While the classifications and the requirements for those classifications are excellent, I don’t agree with specifying the number of cycles each type of mold should be able to produce.

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

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.

• Gate design: In parts that are subject to high wear during use, and consequently prone to layer delamination, gates should be positioned in the areas that will receive highest wear. That’s because TPEs are hotter (and thus generally adhere better) at the gate rather than at the end of flow. When appearance is a priority, as in cosmetics packaging, gating from the back of the substrate via a pin is preferred since it hides gate blemishes on the TPE.

The yield strength of P-20 steel is about 125,000 psi. The yield strength of 1030 and 4130 steel is about 64,000 psi. This equation doesn’t even include the added force applied to the debris due to the closing speed and momentum of the moving platen. Figure 3 shows what gate flakes can do to a mold when the applied pressure is considerably greater than the yield strength of the steel.

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

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.

Over the past decade, soft-touch overmolding has radically changed the look, feel, and function of a broad range of consumer products.

Proper steel selection plays a critical role in the longevity of a mold. Most moldmakers have their “go-to” types, such as 1030 or 4130 for the mold base and P-20, 420 or H-13 for the cavities and cores. 1030 and 4130 are good steel types for mold bases, but if the project needs to last for several years, or if the water quality in the molding facility is prone to calcium deposits, the mold base should be electroless nickel plated.

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

The PLASTICS document is meant to be a guideline for purchasers of injection molds, and it should be renamed accordingly—guideline. The problem is that many people consider the stated minimum cycle counts to be factual, if not contractual. And that can lead to problems down the road. What happens to a class 101 mold at a million and one cycles? The customer pays for all the maintenance and repairs to the mold—regardless of how small or how large the cost? What happens at 999,000 cycles if a cavity cracks? Does the moldmaker have to replace it at his cost? As unpleasant as this topic is, it may be worth setting some initial ground rules with your customers.

3. What is the molding material? If it’s a corrosive resin, such as rigid PVC, the only good option is to make the mold out of stainless steel. I say the only good option because nickel and other coatings do not protect carbon steels from PVC gases for very long. If you think that stainless is too expensive, consider the cost to remove the worn or flaking plating, re-polishing the cores and cavities and then re-plating the mold.

Scientists use the Otter Box to gather data in demanding outdoor environments. The soft TPE’s roles are to provide a waterproof seal, impart a grippy feel, and adhere strongly to the PC-ABS substrate.

To ensure that the TPE melt adequately fills the mold cavity, a key consideration is the ratio between flow length and part thickness. The minimum ratio should be around 150:1. Another proven approach is to locate the gate at the thickest area of the part and to keep flow length as short as possible.

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

1. What is the expected annual quantity? This helps the moldmaker decide the mold classification and the number of cavities required to meet those annual quantities.

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

The best way to reach the optimal TPE melt temperature is to approach it gradually, not necessarily by increasing barrel temperature, but via higher screw rpm or injection speed. A problem in determining the actual melt temperature is that it is not always equivalent to injection nozzle temperature. A sensible approach is to use a pyrometer to measure melt temperature of a TPE air shot.

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.

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

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.

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

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

A critical challenge for designers and producers of these parts is poor adhesion of TPE to substrate, which reveals itself in peeling, curling, fraying, or delamination of the material layers. Initially, this was a fairly straightforward issue since the most common approach was to combine an olefin-based TPE with a compatible rigid PP substrate.

Where the TPE layer is less than 0.060 in. thick, the feel of a soft elastomer can easily be negated by the hardness of the underlying substrate. The degree of cushioning provided by a TPE layer is also greatly influenced by the substrate’s inherent hardness.

In both processes, strength and durability of adhesion between TPE and substrate require compatible hard and soft materials. The type of overmolding method used also affects adhesion performance: Multi-shot molding, by bringing together several melt fronts, generally offers superior adhesion. Adhesion performance is also affected by a number of additional factors:

Since prying fingers tend to challenge adhesion in soft-touch infant products, molding technique and tool design are especially critical.

Personally, I have a passion for using thermally conductive materials, especially in hard-to-cool areas. Not because they are great at reducing cycle time, but because they are great at achieving uniform cooling. Non-uniform part cooling invites part warpage, and warped parts are often a rejectable condition. Table 2 gives approximate thermal-conductivity values for various mold materials. These values can vary widely depending on the manufacturer, heat treatment and operating temperature.

An uncommon, but very serious crash can occur when a large mold is hung in the machine in two halves. If one of the halves is accidentally oriented 180° out of position and the setup man overrides the low-pressure setup mode because the mold won’t close, really bad things happen. On a couple of occasions, I have seen a molding machine with a bad hydraulic valve. The mold closed at full velocity and shook the entire building. But accidental mold crashes are thankfully infrequent and one-time events.

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