Tight Tolerances & Material Selection

April 7, 2021  |  , , , , , ,

Plastic injection molding continues to become more and more sophisticated with part tolerances becoming tighter and tighter. Initially, tight tolerance was defined as +/-.002 inches and a very tight tolerance is +/-.001 inches. But today there are many factors that impact tight tolerance including part complexity and size, resin selection, tooling, and process conditions. So, getting the mold, part design, material selection and process correct is crucial when working with a product that requires tight tolerances.

Tight tolerances are essential when manufacturing complex parts, especially in the aerospace & defense, medical & life sciences, and diversified industrial sectors.  A few thousandths of an inch can be the difference between a component that fits and one that does not – if tight tolerances are not achieved properly the resulting products may underperform. So, it is critical that clients understand tight tolerances and their underlying objectives. Performance Plastics has parts in production that are +/-.0004 inches. Parts are measured in their Metrology lab with a CT Scanner.

 

Benefits of Tight Tolerances

There are many benefits to manufacturing parts with tight tolerances. It ensures that parts work together smoothly and fit as intended in their final form; parts mesh well and deliver enhanced functionality.   They produce lower failure rates and result in higher client satisfaction. Tight tolerances can also result in fewer post-molding processing requirements.  Additionally, tight tolerances allow for parts to be transitioned from metal to plastic, reducing overall weight and cost of the final product. This can be very advantageous in some industries, such as aerospace and defense.

Design for Tight Tolerances

Not every plastic injection molding project requires tight tolerances, and some organizations insist on tight tolerances for non-critical features.  Tight tolerance should only be required in instances where they are critical.  Many products require standard tolerancing because the consequences of failure are low.  As a general rule, designers should keep tolerances as large as possible while maintaining the desired functionality of the part.

Materials for Tight Tolerances

Additionally, material selection is a critical element in achieving tight tolerances.  Certain resins perform better under certain circumstances.  An experienced design engineer can guide a client in choosing the most affordable material that will deliver the best result.  So, it’s critical to bring in an experienced team early in the design process.

By engaging a production team during the design phase, part functionality, material selection and design can be discussed upfront, and the team can jointly develop a manufacturing process and correct materials that will produce high-precision components. It is crucial for organizations to partner with an experienced injection molder, who has expertise; the design and manufacturing teams should be integrated to allow manufacturability issues to be identified and addressed during the design process – thus saving significant time and unnecessary cost.

Establishing the right process and correct materials for each product and developing repeatability are key to manufacturing tight tolerance parts. While every application is different, there are some process and material conditions that impact tolerances. For example, quick cavity filling and uniform cooling at the desired temperature are conditions that are crucial to achieving repeatability, and thus, parts with tight tolerances.

Performance Plastics is highly skilled at designing and molding using high performance materials such as PEI-Ultem®, PAI-Torlon®, Ryton® PPS Plastic, PEEK, and Fluoropolymers such as FEP, PFA, and PVDF.  We work with our customers to solve technically challenging problems.   We can propose materials to implement part functionality in the design stage of development. We offer manufacturing solutions such as a clean room, the ability to offer direct gating of fluoropolymers, high volume production, visual inspection, and automated facilities.

For more information and solutions, please contact Rich Reed, Vice President of Sales & Marketing at 513-321-8404 or email [email protected]

 

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Injection Molded PFA & PPSU in the Lithium Ion Battery

March 3, 2021  |  ,

The Lithium Ion Battery industry has begun using more and more plastic parts in their manufacturing processes. Most batteries intended for light vehicle usage now have 50% more plastic materials than they did even 10 years ago.  Some batteries have entirely plastic formulations ranging from the electrolyte (polymeric electrolytes) to the casing.  This is due to the very low weight of plastics as compared to metals. Plastic incorporation in batteries increases the electrolyte efficiency if used in polymeric electrolytes.

Commercially available lithium-ion batteries also use plastics. Plastic components incorporated in batteries include separators, gaskets, and casing components. Plastics have good shock absorbing characteristics and prevent damage to the basic cell unit from minor accidental shocks. Also, plastics such as Teflon® PFA, Ultem® PEI, and PPSU have high temperature resistance, corrosion resistance, and are electrical insulators so they are excellent at preventing short-circuit and “rapid disassembly.”

There has been a major shift from metal to resins in gasket manufacturing. Gaskets can be made from Ultem®, Ryton plastic and Fluoropolymers like PFA because of high heat resistance, chemical resistance, and ability to mold thin walls (.012”). Plastic parts may also lower the cost of production of batteries and may eventually replace most metallic components of batteries.

Performance Plastics is highly skilled at designing and molding high performance materials such as FEP/PFA, Ultem®, Torlon®, PEEK, POM, and PPS.  We work with our customers to solve technically challenging problems.   We can propose materials to implement part functionality in the design stage of development. We offer manufacturing solutions such as a clean room, the ability to offer direct gating of fluoropolymers, high volume production, visual inspection and automated facilities.

For more information and solutions, please contact Rich Reed, Vice President of Sales & Marketing at 513-321-8404 or email [email protected]

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Designing and Molding Complex Plastic Parts

January 27, 2021  |  , , , , , ,

Every project has its own needs and goals.  Complex geometries involving fine details or sharp corners often cannot be achieved by traditional plastic molding. Advanced plastic injection molding processes allow designers to combine numerous complex features into a single component, reducing the need for secondary machining or surface finishing operations.

Plastic Injection molding allows design freedom not easily matched by other traditional processes.  Performance Plastics’ augments the latest software tools including solid modeling, mold flow analysis and finite element analysis with an internally developed iterative tool design approach to deliver complex geometries and densities superior to most other operations.

Our tooling modification process results in best in class part tolerances, particularly useful in molding mission critical parts where dimensional attributes need to be extremely precise.  We use this approach to produce net shape molded parts of exceptional quality, eliminating or significantly reducing secondary matching operations resulting in material and process cost savings.

Performance Plastics, located in Cincinnati, OH has over 30 years’ experience in molding tight tolerance advanced plastics such as Fluoropolymers (FEP/PFA Torlon, Ryton plastic, Peek & Ultem) for many industries.  We have developed proprietary processes enabling injection molding of parts that are thin walled, with tight dimensional tolerances, and complex geometries.

For more information and solutions, please contact Rich Reed, Vice President of Sales & Marketing at 513-321-8404 or email [email protected].

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Injection Molded Plastic Fluoropolymers to manufacture UV-C Sanitization Devices

December 17, 2020  |  ,

UV-C light can be used to kill germs such as bacteria, viruses such as Covid-19, and spores. UV-C light disrupts the DNA of pathogens, eliminating their ability to replicate This technology works by the line of sight so the light must reach the surface in order for the bacteria or virus to be deactivated.

Historically, medical device manufacturers did not consider plastics to mold parts because plastic resins posed the possibility of cross contamination.  Today, medical device engineers are reconsidering plastics, specifically fluoropolymers that can be formulated to resist UV-C light degradation and reflectivity to leverage sterilization benefits and part manufacturing flexibility.

Fluoropolymers or Teflon®, are a group of high-performance plastics with excellent temperature and chemical resistance that are increasingly being injection molded in a variety of medical products today.  Unique characteristics such as UV-C light reflectivity, biocompatibility, low friction, chemical inertness, non-porosity, and compatibility with UV-C sterilization technologies, make them suitable for uses in many types of medical devices.

Fluoropolymers, such as FEP and PFA are resistant to higher transmission rates of UV light than glass, polyethylene, or polycarbonate allowing the full spectrum of solar light to pass through offering the benefits of sterilization.  These fluoropolymers are flexible and do not discolor, making them an ideal material to produce medical components to be UVC sterilized.

Performance Plastics, located in Cincinnati, OH  has over 30 years’ experience in molding tight tolerance advanced plastics such as Fluoropolymers (FEP & PFA) for the medical industry.  We have developed proprietary processes enabling injection molding of parts that are thin-walled, tight dimensional tolerances, and complex geometries.

For more information and solutions, please contact Rich Reed, Vice President of Sales & Marketing at 513-321-8404 or email [email protected].

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Understanding All Aspects of Your Part

August 25, 2020  |  , , , , , ,

Performance Plastic’s  Metrology Lab focuses on advancing measurement science through our ability to understand all aspects of your part.  Mechanical Engineer, Jordan Murray, dives into our industrial computed tomography (CT) Scanning process, explaining the benefits of CT Scanning and how it helps us to solve your problems.

To learn more about Performance Plastic’s CT Scanning process contact Rich Reed, our Vice President of Sales and Marketing, at (513) 321-8404 or [email protected].

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Fluoropolymers can be your solution for glass shortage

July 31, 2020  |  , ,

The shortage in glass has been an ongoing issue. This year with restaurants and bars being closed we have seen a greater shortage in the glass industry. The collection of wine and beer bottles from restaurants contributes to a large volume of recycled glass needed to meet demands. The glass shortage affects all industries that rely on glass for their containers, but right now the medical field is in dire need of glass for vials.

The Covid-19 pandemic has created a lot of ripple affects on various industries. The decrease in the recycling rate during the pandemic, is inadvertently hurting the production of glass vials. The pandemic has also increased the need of vials for the Covid-19 vaccine. Public health experts have estimated between 7 billion and 14 billion vials will be needed to distribute the vaccine. With the demand of vials going up and the supply of glass going down the need for an alternative material to create the vial is needed.

Fluoropolymers such as FEP, PFA, and PCTFE are great alternative materials for glass. These fluoropolymers are superior to conventional plastics. Their inert, non-reactive, and unmatched durability makes their properties ideal for use in the medical industry. These fluoropolymers are also non-stick, ensuring product does not adsorb to surfaces. They are also virtually impervious to chemical, enzyme and microbiological attack. All the benefits of FEP, PFA, and PCTFE make these fluoropolymers a perfect material to create vials out of, especially since they are injection moldable.

At Performance Plastics, we have extensive experience injection molding fluoropolymers. We have developed proprietary tooling and processes enabling the injection molding of small, thin-walled, complex parts. Our expertise in fluoropolymers and injection molding can be your solution to the shortage in glass.

For more information on how to use fluoropolymers as your glass shortage solution contact Rich Reed, our Vice President of Sales and Marketing, at (513) 321-8404 or [email protected].

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The Key to Clean Surfaces

July 17, 2020  |  , , ,

Covid-19 has impacted our world in more ways than one. The ability to keep your office, workspace, and your whole environment sanitized has increased greatly. The use of cleaning supplies for sanitation increases depending on the type of surface that you are sanitizing. Some surfaces are more porous than others needing to be sanitized more often to maintain a clean environment. At Performance Plastics, we deal with different types of plastics every day, making us experts in various materials that excel in a clean environment.

The type of material a product is made from is a big factor when keeping a clean environment. We have a wide array of high-performance plastics to choose from for your product, however, our go to material for clean environments is always Fluoropolymers. Fluoropolymers are virtually impervious to chemical, enzyme and microbiological attacks while eliminating biodegradation issues. The non-stick properties of these polymers reduce adhesion, making it the perfect surface for clean environments. The ability to keep liquids, gel, powder and other contaminates from sticking to the surface is what makes fluoropolymers safe for clean environments. There are various types of fluoropolymers such as PTFE, PFA, and FEP. Each polymer has their own strengths and weaknesses when it comes to various applications.

For more information on Fluoropolymers, contact Rich Reed, Vice President of Sales and Marketing, at (513) 321-8404 or [email protected].

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Biocompatible Fluoropolymers

April 3, 2016  |  , , , , , ,

Injection Molding Biocompatible Fluoropolymers For Medical Device Industry

Biocompatible Fluoropolymers And Advances In Injection Molding These Materials For Medical Devices, Drug Delivery Systems And Storage Components

Abstract

Injection molded fluoropolymers provide the chemical resistance and material performance needed for the manufacturing, storage and delivery of next generation cancer and biologic drug technologies. Fluoropolymers barrier properties, thermal properties and low surface adhesion characteristics offer advantages for powder and viscous liquid manufacturing, storage and delivery components.

In the past, fluoropolymer were not often considered for high volume parts with complex geometries due to injection molding process limitations. Developments in mold design and tooling steels combined with new manufacturing equipment and processing techniques now allow the use of these biocompatible materials for high volume drug storage and delivery components.

Introduction

Polyethylenes, polypropylenes and polycarbonates currently used for drug storage containers and delivery components will struggle to meet future efficacy requirements. Next generation drug technologies are bringing new handling and dispensing challenges because of increased chemical resistance and cytotoxicity issues. Long-term storage  solutions that  maintain performance and extend shelf life will be required. Improvements in dosage control and minimizing or eliminating the use of silicone coating operations in drug delivery components have also become industry wide concerns. Because of the elimination of traditional injection molding process limitations, product design engineers can now cost- effectively use fluoropolymers inherent material property benefits to address these issues.

Fluoropolymer Material Benefits

Fluoropolymers are chemically inert and pure generally containing no additives that could contaminate liquids or solids during storage or delivery. Fluoropolymers barrier properties resistance to chemical, enzyme and microbiological attack also eliminate biodegradation issues.

Barrier Properties of Thermoplastics

 

Figure 1. Barrier Properties of Thermoplastics

Compared to current plastics, the barrier properties of fluoropolymers (Figure 1) are exceptional. Aging, even at high temperatures and in the presence of solvents, oils, oxidizing agents, ultraviolet light and other environmental agents, is minimal because fluoropolymers do not use any leachable or degradable stabilizing additives. Fluoropolymers  also  have  a  low  refractive  index  and visual  appearance  that  is  unchanged  after  exposure  to light. Applications include drug containers and delivery systems components including bottles, vials, syringes and specimen trays.

Low Surface Energy Material Comparison

 

Figure 2. Low Surface Energy Material Comparison

Fluoropolymers have one of the lowest coefficients of friction of any solid material (Figure 2). Low surface energy in its solid state provides an anti-stick, non-wetting contact surface that is hydrophobic and completely resistant to hydrolysis. For sprays and inhalers, fluoropolymer manifolds can minimize drug delivery buildup to assure consistent dosing. Other applications include medical devices, surgical equipment, syringes, plungers, valves and connectors.

Fluoropolymer Processing

Concerns about fluoropolymer material application and processing limitations are prevalent.  It is still generally thought that sintering or machining are the only viable alternatives because of corrosion and thermal issues during the traditional injection molding process.  Temperatures of molds and equipment can range from 300°F to 800°F.

Highly toxic gases produced have an extremely corrosive effect on both molds and machines. Mold deterioration, runner system scrap rates, melt fracture, delamination and dimensional limitations of traditional gating methods. New fluoropolymers, processing equipment and manufacturing methods have been developed to address both by-product and material waste issues.

Continue reading by clicking, Performance Plastics white paper on fluoropolymers for the medical device industry or contact us to learn more.

 

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Proprietary Fluoropolymer Injection Molding Process

February 12, 2016  |  , , , ,

Cost Effective Fluoropolymer Molding

  • Market: Medical/Life Science
  • Project Requirement:  Manufacture a cost effective, conforming fluoropolymer part

Fluoropolymers (PFA, PEF. ETFE, PTFE, PVDF) are ideal for many medical applications due to their desirable attributes including biocompatibility, lubricity, sterilization, chemical inertness, stability over a wide temperature use range, barrier properties and high-purity with low extractables and leachables. However, fluoropolymers are relatively expensive and are difficult to injection mold (shear sensitivity, high melt temperature, and fluorine outgassing when melted).

Overview

Our customer, a manufacturer of diagnostic lab equipment, developed a new system automating a critical, but time consuming, manual diagnostic process. This system greatly reduced processing time, but utilized PFA, an expensive material, in its small (features as small as 0.20 mm), thin-walled (down to 0.30 mm), highly complex consumable parts. In fact, prior to contacting Performance Plastics (PPL), the customer had worked with other high end molders, who while even ignoring cost, were unable to manufacture the part.

Challenge

As mentioned above, fluoropolymers by their nature are difficult to mold. Further complicating the challenge was the highly complex, thin walled design of the part. The customer was looking for a way to cost effectively manufacture a compliant part.

Solution

The customer, on advice from its material supplier, contacted PPL to develop a cost effective injection molding solution. PPL leveraged its extensive fluoropolymer expertise in designing a solution to this challenging component. Our solution began with a hot runner system and mold designed to greatly reduced shear forces inherent in the injection molding process. Mitigating shear is key to preserving the mechanical properties inherent in the resin. Further, PPL utilizes proprietary metallurgy highly resistant to corrosion from fluorine gas. This significantly extends the useful life of the hot runner system, tooling and all other wetted component coming in contact with the melted resin. Lastly, PPL engineers incorporated a direct gated multi-cavity tool design eliminating the sprue and runner associated with traditional injection molding processes. Employing a direct gated tool design removes the material waste associated with the sprue and runner, particularly important when utilizing expensive resins such as fluoropolymers.

Results

PPL was able to produce a compliant part within 60 days while meeting their cost target. This allowed the customer to successfully introduce its new automated diagnostic system. The multi-cavity mold has reduced the production cycle and lowered the amount of required raw and finished goods inventory. Additionally, the advanced metallurgy developed has been leveraged to produce longer life/lower maintenance molds for other chemically reactive or abrasive resin systems.

For more information about our proprietary molding process please contact us.

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