Blog

How to Extrusion Blow Mold PHA/PLA Blends | Plastics Technology

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. Boat Blow Mould

How to Extrusion Blow Mold PHA/PLA Blends  | Plastics Technology

Everything you need to know about plastics compounding technology—from feeding solutions to application profiles and expert advice.

Combat the skilled labor shortage using this comprehensive resource to train your own plastics processing experts.

Deep dive into the basics of blending versus dosing, controls, maintenance, process integration and more.

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

Learn about sustainable scrap reprocessing—this resource offers a deep dive into everything from granulator types and options, to service tips, videos and technical articles.

While price initiatives for PE and PVC were underway, resin prices had rollover potential for first two months of 2024, perhaps with the exception of PET.

Flat-to-downward trajectory for at least this month.

A mixed bag, though prices likely to be down if not flat for all this month.

Trajectory is generally flat-to-down for all commodity resins.

Flat-to-down trajectory underway for fourth quarter for commodity resins.  

Generally, a bottoming-out appears to be the projected pricing trajectory.

Resin drying is a crucial, but often-misunderstood area. This collection includes details on why and what you need to dry, how to specify a dryer, and best practices.

Take a deep dive into all of the various aspects of part quoting to ensure you’ve got all the bases—as in costs—covered before preparing your customer’s quote for services.

In this collection of articles, two of the industry’s foremost authorities on screw design — Jim Frankand and Mark Spalding — offer their sage advice on screw design...what works, what doesn’t, and what to look for when things start going wrong.

In this collection, which is part one of a series representing some of John’s finest work, we present you with five articles that we think you will refer to time and again as you look to solve problems, cut cycle times and improve the quality of the parts you mold.

Gifted with extraordinary technical know how and an authoritative yet plain English writing style, in this collection of articles Fattori offers his insights on a variety of molding-related topics that are bound to make your days on the production floor go a little bit better.

In this three-part collection, veteran molder and moldmaker Jim Fattori brings to bear his 40+ years of on-the-job experience and provides molders his “from the trenches” perspective on on the why, where and how of venting injection molds. Take the trial-and-error out of the molding venting process.

Mike Sepe has authored more than 25 ANTEC papers and more than 250 articles illustrating the importance of this interdisciplanary approach. In this collection, we present some of his best work during the years he has been contributing for Plastics Technology Magazine.

In this collection of content, we provide expert advice on welding from some of the leading authorities in the field, with tips on such matters as controls, as well as insights on how to solve common problems in welding.

Mold maintenance is critical, and with this collection of content we’ve bundled some of the very best advice we’ve published on repairing, maintaining, evaluating and even hanging molds on injection molding machines.

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

Medical-component specialist LightningCath has carved a niche meeting the needs of small to medium-sized entrepreneurs with complex catheter designs … quickly.

Plastics Technology is closing in on its 70th anniversary. Here are some of Editorial Director Jim Callari’s observations to commemorate the occasion.

As with everything else, there are pros and cons, but more of the former. They provide processors higher rates while decreasing the temperature of the extrudate while enabling downgauging.    

The drop in plastics activity appears to be driven by a return to accelerated contraction for three closely connected components — new orders, production and backlog.

Beginning the first of this year, 12 states are following EPA bans on potentially damaging cooling fluids. Chiller suppliers have adjusted equipment designs to accommodate the new regulations. Here’s what all this means to processors.  

Pairing external big picture training with internal job-specific instruction can help your process technicians meet quality expectations as well as production targets.

In less than a decade in injection molding, US Merchants has acquired hundreds of machines spread across facilities in California, Texas, Virginia and Arizona, with even more growth coming.

Demand for bioresins is growing in molded goods, particularly as a sustainability play to replace fossil-fuel based materials, but these materials are not a drop-in replacement for traditional materials. Molds and hot runners need to be optimized for these materials.

There are many things to consider, and paying attention to the details can help avoid machine downtime and higher maintenance costs — and keep the customer happy.

Flat-to-downward trajectory for at least this month.

Topping five other entries in voting by fellow molders, the Ultradent team talks about their Hot Shots sweep.

Serendipitous Learning Opportunities at PTXPO Underscore the Value of Being Present.

Introduced by Zeiger and Spark Industries at the PTXPO, the nozzle is designed for maximum heat transfer and uniformity with a continuous taper for self cleaning.

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

technotrans says climate protection, energy efficiency and customization will be key discussion topics at PTXPO as it displays its protemp flow 6 ultrasonic eco and the teco cs 90t 9.1 TCUs.

Shibaura discusses the upcoming Plastics Technology Expo (PTXPO) March 28-30

Competition will invite participants to help reshape life cycle management in plastics.

Sign up to attend North America’s leading trade show for plastics.  

Offerings range from recycled, biobased, biodegradable  and monomaterial structures that enhance recyclability to additives that are more efficient, sustainable and safer to use.  

Ahead of the first NPE since 2018, PLASTICS announced that its triennial show will stay in Orlando and early May for ’27, ’30 and ’33.

New features of NPE2024 aim to “bring the whole plastics ecosystem together to innovate, collaborate and share findings.”  

Hundreds of tons of demonstration products will be created at NPE2024 next spring. Commercial Plastics Recycling strives to recycle all of it.

Mixed in among thought leaders from leading suppliers to injection molders and mold makers at the 2023 Molding and MoldMaking conferences will be molders and toolmakers themselves. 

After successfully introducing a combined conference for moldmakers and injection molders in 2022, Plastics Technology and MoldMaking Technology are once again joining forces for a tooling/molding two-for-one.

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

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

As self-imposed and government-issued sustainability mandates approach, injection molders reimagine their operations.

August 29-30 in Minneapolis all things injection molding and moldmaking will be happening at the Hyatt Regency — check out who’s speaking on what topics today.

Get your clicking finger in shape and sign up for all that we have in store for you in 2023.  

Molding 2023 to take place Aug. 29-30 in Minnesota; Extrusion 2023 slated for Oct. 10-12 in Indiana.

Key technologies — such as multicolor molding, film molding and PUR overmolding for both exterior and interior applications — are at the forefront of this transformation. Join this webinar to explore the vast potential of eMobility in molding large components — including those with fiber reinforcements — thereby driving the need for large injection molding cells with a clamping force of up to 11,000 tons. You will also gain insight into Engel's innovative two-stage process, a solution for future recycling processes. This webinar will provide an in-depth overview of challenging applications, production concepts and best practices, including:       BMW iX front panel production cell Smart rear panels concept based on IMD and 2C molding Sustainability concepts based on two-stage process Large tonnage equipment for battery moldings

In today's manufacturing environment, robust processes that meet strict industry and regulatory standards are essential. With the advent of servo-driven ultrasonic welding technology, enhancing product quality and maintaining consistency has become remarkably effortless. Discover the fundamentals of ultrasonic welding, delve into vital components within these systems, explore how servo-driven ultrasonic welding enhances weld quality via advanced control features and gain insights into optimizing your assemblies for welding in these high-performing machines. Join Dukane to unlock the potential of ultrasonic welding in modern manufacturing for plastic devices and components. Agenda: Fundamentals of ultrasonic welding Key components in an ultrasonic welding system Using servo-driven ultrasonic systems to control your welding process Designing your parts and components for servo-controlled ultrasonic welding

This webinar will help you make informed decisions to confirm the equipment access stairs in your facility are OSHA compliant and meet the highest standards of safety and ergonomics. Agenda:  Identifying opportunities to increase safety in the work place Utilizing space saving stairways Ensuring code compliance for equipment access

4.0, EUROMAP, OPC, OLE, QC, DSN, SQL, VNC, MES, ERP, FTP, CMS, SPI — are you confused by all buzzwords being tossed around in the plastics industry? Not convinced the data collection is necessary? Or are you unsure of how it could be implemented and improve your molding processes? Wittmann has been on the cutting edge of the data collection push for nearly 20 years. In this webinar, take a step back from the idea of the manufacturing facility of the future and discuss what you can do today to improve your process. Using readily-available technology, Wittmann can help reduce downtime, limit scrap and wasted material, and predict required maintenance. Let the experts at Wittmann help you understand: what data can be collected, what that data can be used for, what systems are used, and how to implement them. Agenda: Demystifying the terminology Tracking the material flow and lot information through the material handling system The data available from various auxiliary equipment, such as: dryers, blenders, mold temperature controls and robots Automating the process through changes in the data collected at the machines during production Adding visualization to increase productivity

Learn how targeted, modular, dosing and blending solutions — covering powders, granules, regrinds and liquids — provide plastics processors of all kinds with best-in-class accurate dosing while delivering significant raw material savings and ensuring highest quality.  Agenda:  Introduction to Movacolor Blending in plastics applications Movacolor feeding and dosing technology Hybrid blending to combine high material throughput and dosing accuracy

This presentation will explore the in-situ polyurethane (PU) overmolding of injection-molded and composite parts, allowing for direct out-of-mold class "A" surfaces. KraussMaffei will review the process and equipment required. It will also discuss tooling types currently available for PU systems for this process. KraussMaffei will compare the pros and cons of this technology over currently-available coating and painting systems. Agenda: Introduction and evolution of the ColorForm technology Overview of the ColorForm process Equipment required Tooling and PU systems Benefits of the system compared to typical spray-applied coatings Pros and cons of the technology

The global plastics industry has been navigating through what is arguably the most volatile period in decades. Unprecedented amounts of new production capacity are scheduled to start in North America, Europe, and China in the near term and compete for demand during a period of economic challenges. How will trade flows shift? Will this lead to regional cost disparities and rationalization? Energy transition and sustainability targets continue transforming the plastics market and increasing the competitive landscape. As the market evolves, what impact will new technology, policy, regulation, the growing role of chemicals versus fuel and other factors have on industry restructuring and business models? At GPS 2024, leading global experts will come together to discuss pivotal impacts and initiatives shaping the plastics industry. Join us and participants from across the globe to gain the latest insight and deep analysis as you connect with your peers and industry professionals. This year’s conference will explore the theme Disruptive Global Dynamics Reshaping Plastics and include a full day workshop focused on the Global Plastics Business and Plastics Transition to Circularity, 1.5 days of expert content and numerous networking functions.

Every three years, leaders from almost every major industry gather at NPE to advance their businesses through innovations in plastics. The largest plastics trade show in the Americas, NPE offers six technology zones, keynote speakers, workshops and opportunities to build partnerships. 

The 3D Printing Workshop @ NPE2024 – The Plastics Show, is an immersive, half-day workshop focused on the emerging possibilities for part production via 3D printing and additive manufacturing. Presented by Additive Manufacturing Media, Plastics Technology and MoldMaking Technology, the 3D Printing Workshop will build upon a successful model first introduced at IMTS 2014. Attendees will benefit from a program focused on practical applications of 3D technologies related to plastics processing. This event will conclude with a 3D Printing Industry Reception sponsored by Additive Manufacturing Media.

The Society Plastics Engineers (SPE) Extrusion Division and the SPE Eastern New England Section will co-host the Screw Design Conference-Topcon on June 19-20, 2024 @ UMass Lowell in Lowell, MA.  This highly technical program will focus upon screw design principles for single and twin screw extruders with wide ranging topics relating to screw designs for feeding, melting, mixing, venting and pumping plastics products and parts.   Areas of focus will include screw designs for melt temperature and gel management, gel minimization, bioplastics, recycled materials and foaming.   In addition to the technical sessions, a tour of the UMass Lowel Plastics Processing Laboratories will be integrated into Day 2 of the event.    This program is not just for screw designers, but to help anyone responsible for any type of extrusion operation to evaluate existing extrusion equipment; and also to prepare for future projects. Price to attend:  Less than $1000!  Registrations will be accepted in early 2024. Call for papers – To be considered to give a presentation, please submit a talk title and abstract on or before December 15 to:   Technical Chair: Eldridge M. Mount III, e-mail emmount@msn.com Corporate sponsorships - A limited # of corporate sponsorships (15) are available on a 1st come basis.  Included is a 6’ tabletop display (must fit on table), denotation in all promotional activities, and 1 no charge registration.  To become a sponsor contact: Charlie Martin, Leistritz Extrusion, e-mail cmartin@leistritz-extrusion.com, cell 973-650 3137 General information:   A reception on Day 1 and a tabletop display area will allow the attendees to meet and discuss state-of-the-art screw technologies with industry experts.  The SPE Extrusion Division will issue a “Screw Design Certificate” to all participants who have attended the program.  Students are encouraged to attend and will receive a discounted rate.   For additional information contact:  Program Chair:  Karen Xiao, Macro Engineering, KXiao@macroeng.com

Debuting in 2010, the Parts Cleaning Conference is the leading and most trusted manufacturing and industrial parts cleaning forum focused solely on delivering quality technical information in the specialized field of machined parts cleansing. Providing guidance and training to understand the recognized sets of standards for industrial cleaning, every year the Conference showcases industry experts who present educational sessions on the latest and most pressing topics affecting manufacturing facilities today.  Discover all that the 2022 Parts Cleaning Conference has to offer!

Presented by Additive Manufacturing Media, Plastics Technology and MoldMaking Technology, the 3D Printing Workshop at IMTS 2024 is a chance for job shops to learn the emerging possibilities for part production via 3D printing and additive manufacturing. First introduced at IMTS 2014, this workshop has helped hundreds of manufacturing professionals expand their additive capabilities.  

You need to pay attention to the inherent characteristics of biopolymers PHA/PLA materials when setting process parameters to realize better and more consistent outcomes.    

In the current legislative climate of bans on petroleum-based plastics and consumer requests for sustainable alternatives, bioplastics offer a unique opportunity. In prior decades, there has been significant resistance to bioplastics because of cost as well as unique, and often difficult, processing characteristics. Now, however, the development of many polyhydroxyalkanoate (PHA)-based resins — often combined with polylactic acid (PLA) — has resulted in bioplastic solutions that are well suited to current market needs.

This is Part 2 in a series on PHA/PLA processing. Part 1 covers injection molding of PHA and PHA/PLA Blends.

PHAs are a naturally occurring biodegradable material produced via bacterial fermentation, similar to brewing alcohol. During fermentation, when nutrients and food sources are optimized, the bacterial strains start making and storing PHA as a food source, eventually producing a peak amount of PHA.

At this point, the PHA is separated from the cellular components and processed, resulting in a light, white powder that can be combined with other materials like PLA to produce processable and usable bioplastic resins. These materials are typically compostable in home and industrial environments, and degradable in soil and marine environments.

One of the opportunities to use PHA and its compostable characteristics is in blow-molded articles. The positive end-of-life scenarios offer one possible solution to the overabundance of plastic in the market. PHA can be blow molded into various shapes, sizes and designs for many applications, from personal use to food and drink storage.

To successfully extrusion blow mold PHA/PLA bottles you need to take heed of the unique processing charactertics of the material. Photos: Danimer Scientific  

Recently, many processors have been experimenting with running PHA/PLA blends in their blow molding operations, with mixed success due to the blends’ unique characteristics. However, proper attention to the inherent characteristics of PHA/PLA materials when setting the processing parameters can lead to better and more consistent outcomes.

PHA can be blow molded molded into various shapes, sizes and designs for many applications.

When combining PHA with PLA, you will find that the processing requirements for the PHA will drive most of your processing strategies. PHA is hygroscopic and needs to be dry. It is sensitive to residence time and requires a warm (120-130°F) mold to crystallize.

At Danimer Scientific, most of our research effort has been with extrusion blow molding (EBM), which is the process covered here.

As noted, PHA is a hygroscopic polyester that will absorb environmental moisture. Having the material dry before processing will prevent degradation and melt thinning. A moisture content of less than 0.04% (400 ppm) is required. Recommended drying conditions are four hours at no greater than 170°F (80°C) with a desiccant dryer.

It is recommended to purge the machine completely with LDPE to remove the previous resin and, after cooling the extruder to the process set points referenced below, introduce the PHA/PLA blend. This procedure should get you into the production material without degrading the resin. PHA/PLA blends have an upper temperature limit of around 400°F and will rapidly degrade around this temperature.

Because PHA can degrade quickly under heat and shear, it is recommended that you purge fresh material forward anytime the machine is idled for more than five minutes before starting up again. It is not only the temperature of the melt that matters but also the residence time. High residence times will cause the material viscosity to decrease and can cause problems with machine startup.

At the end of production, the machine should again be purged clear of the PHA/PLA blend — using LDPE at process temperatures — before increasing temperatures to go to the next resin.

Once more, the PHA component will drive your temperature strategy. To achieve a stable and workable parison, you must keep your heat near the low end of processing temperatures for PHA.

The low melt temperature aims to achieve a parison with enough melt strength to hold together. You will find that PHA/PLA blends are sensitive to the smallest temperature changes, and viscosity will drop rapidly as melt temperature increases. We typically advise processors new to PHA/PLA blends to think of adjusting temperatures by two or three degrees at a time, not the usual five-degree changes.

While extruder speed is directly related to cycle time, it should be noted that PHA is a shear heating material similar to PVC (polyvinyl chloride). As production rates and extruder speeds increase, you will see temperature override in your extruder zones. If your machine has heat cool bands, you can employ those to keep temperatures inline or you can try to introduce some heat earlier in the extruder to reduce friction and shear heating.

It would also be helpful to look at your extruder screw design and avoid screws with higher compression ratios or very short, aggressive compression sections.

This area requires particular attention. The PHA component of the PHA/PLA blend requires a warm tool to promote timely crystallization. If you process into a cold tool at 40-60°F, the parts will come out soft and pliable and then, over the next 60-90 sec, become firm. What is happening is the part is crystallizing in your hand. The cold temperature is retarding the crystallization rate. When working with PHA/PLA blends, crystallizing and cooling are different. Parts can be cold and not crystallized.

The PHA component of the PHA/PLA blend requires a warm tool to promote timely crystallization.

To aid the crystallization rate, keeping the mold at 110-140°F (40-60°C) is recommended. The strategy is to get the mold warm enough to promote crystallization yet cool enough to enable part ejection and handling.

Another reason to keep the tool warm is that most blow-molded PHA/PLA blends will stick to a cold mold surface, making it difficult to eject them.

Cure time before packaging may be required for PHA/PLA blow molded bottles.  

An important part of any blow-molding process is how you handle the parts once molded. The handling of parts made from PHA/PLA blends will become more difficult as production speeds increase.

As cycle and crystallizing times decrease, the bottles will become softer and easier to damage. It may require some engineering and automation adjustments to enable some post-molding cure time before the parts are bulk packaged.

You may also have to explore some forms of ejection and part holding as the mold opens to keep the bottles releasing consistently due to some variability in whether the bottles will stick to one side or the other or release cleanly.

Hopefully, this outline will provide some basis for developing a process for your parts. If you go at it slowly and methodically, you should be able to create a stable process and then improve from there. Remember that PHA/PLA blends are relatively new and different materials that require some new and different processing techniques.

About the Authors: Russell Mullins is Danimer Scientific’s special operations technical advisor and has more than 45 years of experience in plastics injection molding and product design. Dr. Karson Durie is associate director of Danimer’s facility in Athens, Georgia, and earned a Ph.D. in chemistry from the University of Georgia. Contact: 229-243-7075; russellmullins@danimer.com; danimerscientific.com.

Good news was there if you knew where to look for it—in the pages of Plastics Technology magazine or right here on our website. Here’s a review of headlines you can feel good about.

Other than polyolefins, almost every other polymer exhibits some level of polarity and therefore can absorb a certain amount of moisture from the atmosphere. Here’s a look at some of these materials, and what needs to be done to dry them.

Global bioplastic production capacity is expected to increase to 4.8 billion lb by 2024, driven by OEMs and brand owners steadily converting applications to these “green” materials. If you’re looking to supply compounds to meet this demand, here are some key processing considerations you need to know.

Injection molders are just becoming acquainted with this new class of molding materials. It pays to learn some basic processing guidelines before jumping in.

Here are processing guidelines aimed at both getting the PHA resin into the process without degrading it, and reducing residence time at melt temperatures.

  Private label manufacturer Eagle Beverage to use Danimer Scientific’s Nodax PHA for marine degradable straws and other product categories in the future.

This strategic collaboration will support long-term growth of bioplastics production requiring a blend of PHA and PLA inputs.

How to Extrusion Blow Mold PHA/PLA Blends  | Plastics Technology

Injection Blow Molding Machine For Large Balls 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