DOWNLOAD: Transition IVD Prototypes to Mass Production

Enplas customizes development and manufacturing services to successfully transition your IVD prototype to mass production while minimizing costs, time-to-market, and stress. Enplas manages the transition from prototyping to mass production to prevent issues in the manufacturing stage and product reliability.

Autofluorescence of Plastics in Microfluidic Devices

The development of microfluidics for clinical diagnostic use opened a new chapter in the accessibility of lab tests known as “lab-on-a-chip.” These devices bring robustness, reproducibility, and—in particular—miniaturization that is hard to achieve with earlier technologies. From the start, microfluidic technology has depended on plastic for its primary components: plastics can form complex shapes with precision at a microscopic scale and be manufactured in bulk at low cost compared with other materials.

Yet plastics are prone to autofluorescence that can interfere with the performance of a diagnostic device. Many materials autofluoresce at a level that isn’t noticeable to the human eye. However, if you include these materials in a diagnostic device intended to detect or measure fluorescent signal, there can be significant issues.

What is Autofluorescence?

Autofluorescence is the natural emission of light by a material when it has absorbed light. Different materials have different degrees of autofluorescence effects. Some plastics, especially transparent plastics such as COC, COP, and PMMA, tend to have more autofluorescence than glass.

Why is Autofluorescence Important in Device Development, Manufacture, and Use?

Autofluorescence acts as a background noise in diagnostic applications. It can interfere with the reading accuracy of fluorescent signals. This includes detection of reagent mixing, monitoring or reaction progress, and recognition of washing efficiency to achieve consistent reagent concentrations. At worst, it can also obscure final test results of diagnostic applications if directly dependent on the fluorescent signals.

In some cases, you may have finalized your device design (or even created initial prototypes) and are now prepared to transition to hard plastics for injection molding. Special considerations related to autofluorescence are essential during your transition to a new material, particularly when optical monitoring or detection are involved in the operation of the chip.

Can You Eliminate Autofluorescence from Transparent Plastic Microfluidic Chips?

The amount of autofluorescence varies among the plastics used in device manufacturing and varies even more depending on the wavelength of light that excites it. In addition, testing the raw materials before prototyping isn’t sufficient—studies have found that plastic microfluidic chips will have more autofluorescence than their material did before processing. While it isn’t possible to completely avoid autofluorescence, you can minimize its impact. This requires proper knowledge of material grade, channel designs, and injection-molding methods that lessen the overall effect and avoid disruptive interference.

How to Mitigate Autofluorescence Effects on Plastic Microfluidics

During Product Development

It is essential to integrate autofluorescence considerations with your overall product development process. Here are the key steps:

  1. Measure the autofluorescence level of your product and analyze its cause
  2. Determine the optimal material grade and channel design to reduce the amount of autofluorescence.
Measurement and Analysis

To develop a device with minimum autofluorescence interference, you must begin by measuring the amount of fluorescence in conditions that match those of the chip’s intended use. Understanding the range of end-user settings is crucial: physician office labs and clinical diagnostics labs may have different environmental controls, lighting, or even storage conditions of the chips and reagents. Some devices may be intended as manufacturing controls in a factory setting, bringing additional variables to the fore. As part of your design control process, take stock of the full range of conditions across these settings, including humidity, temperature, consistency of reagent use, reagent concentration, chip and reagent storage conditions, light sources, the light’s excitation wavelength and excitation filter, and others that you uncover during your end-user characterization process. Depending on the application or the device, a specific fluorescence, including FAM, HEX, GFP, or Cy5, may need to be measured.

Expert Support for Autofluorescence Evaluation

Enplas can help you define and execute your evaluation of your prototype’s autofluorescence challenges. Our customizable in-house evaluation equipment can replicate the environments in which your customers will use the device and measure autofluorescence levels in those conditions. For Enplas to assist with this measurement, you must provide the reagent itself (or information about which reagent needs to be used). Our evaluation equipment includes the light sources and filters necessary to measure a range of fluorescence including FAM, HEX, GFP, and Cy5. We can support autofluorescence evaluation for any optical detection applications.

Figure 1 shows how the right measurement process can identify areas within your channel design that affect excitation and emission of fluorescence during product use.

Figure 1: Measuring Autofluorescence in Intricate Channels

In addition to conducting standard measurements, Enplas can measure autofluorescence in harder-than-normal situations. For example, Enplas can measure fluorescence from the side of the channel (as shown in Fig. 1). This is more difficult to execute than the more common approach of measuring from above, but it enables measuring autofluorescence in thin wall channels.


Material Grade and Channel Design

The intensity of autofluorescence varies with material grade. Choosing the right material grade of COC, COP, or PMMA can lower the barriers to your successful management of signal interference. Thoughtful channel design informed by the thorough measurement and analysis process described above can significantly reduce autofluorescence. There are several techniques to consider:

  • Thinning the chip thickness at the detection area could minimize autofluorescence for in-channel fluorescent detection.
  • Secondly, increasing the contrast between target detection fluorescence and the background fluorescence can also eliminate noise. Target fluorescence can be intensified by deepening the channel depth.
  • Finally, reducing the thickness of material used for capping the microfluidic channels is very important: films are the most effective. In general, thin films tend to sag and cause issues, but Enplas has lamination technology to bond thin films onto microfluidics without sagging even when the coverage area is a wide channel or large chamber.

During the Product Manufacturing Phase

As the manufacturing phase begins, your design control principles continue to apply. Manufacturing your product with precision based on observations during product development is crucial for mitigation of autofluorescence on plastic microfluidic chips. The manufacturer must be knowledgeable about selecting and preparing the right cleanroom environment, equipment, and machine condition. Design alone cannot prevent autofluorescence. Microfluidic chips which have been flawlessly designed to reduce autofluorescence can be ruined if the right injection molding, monitoring, and maintenance are not conducted.

Molding Process

Autofluorescence effects tend to be stronger when plastics are exposed to higher temperatures for a longer time. However, there are times when high temperatures or long cycle times are unavoidable (e.g., in microfluidics with intricate designs). Scientific molding and microfluidics molding expertise is crucial to identify the ideal molding process to ensure uninterrupted manufacturing of quality chips.

Injection Molding Machine Condition

In precision manufacturing, the condition of the specialized equipment cannot be taken for granted. The smallest particle that might be unimportant in standard injection molding of products can be a real problem when the goal is to reduce autofluorescence effects relating to sensitive microfluidic chips. Meticulous preparation for each manufacturing batch is essential, including:

  • Setting the right amount of heating time
  • Creating the proper cleanroom environment
  • Conducting the appropriate purging
  • Frequent overhauling of each machine

The above are important processes for creating optimal conditions.

Expertise and Proprietary Methods

Enplas has developed a proprietary manufacturing process that optimizes autofluorescence mitigation. Enplas may also designate an injection-molding machine to exclusively run projects that use the same materials as the product requiring low autofluorescence. This eliminates any residual miniscule materials that may negatively affect autofluorescence for applications with strict requirements. The presses are monitored in real time to ensure our autofluorescence-mitigating molding process is on track. We offer ISO Class 6 to Class 8 cleanrooms, depending on your company’s need.

In Figure 2 below, each group of plots represents one production day and shows the measurement of autofluorescence intensity of microfluidic chips injection-molded during that day. (Blue plots represent Day 1, and orange plots represent Day 2.) The data show how unregulated injection molding (Day 1) can yield chips with high fluorescence intensity despite good product design. On Day 2, Enplas improved the injection-molding process so that all shots stayed in the low fluorescence range (orange plots).

Figure 2: Benefits of an Optimized Manufacturing Process for Reduction of Autofluorescence

Generally, as the injection molding makes more shots, the level of autofluorescence decreases (Fig. 2). However, there are times when unexpected issues cause a sudden increase in autofluorescence. To prevent this, Enplas monitors the process throughout the entire running time. If any abnormalities are detected that cause high fluorescence, the run can be stopped and the process can be adjusted to prevent loss of time or product.


Autofluorescence of plastic microfluidic chips is inevitable. For any product that involves accurate reading of fluorescence, it must be considered in the design control process to achieve its desired result. Autofluorescence effects on plastic microfluidic chips can be reduced with proper decision and handling during the design development and manufacturing phases. It is important to work with a manufacturer that has the expertise and technology to help you produce microfluidic chips with minimized autofluorescence.

Enplas conducts original research to study autofluorescence effects on plastic microfluidic chips and applies that expertise to help customers during the design development phase. Enplas supports you in achieving optimal product design with low autofluorescence interference. The microfluidic chips mass produced by Enplas will be delivered with stable levels of reduced autofluorescence.

Contact Enplas today for consultation on how you can mitigate autofluorescence on your plastic microfluidic device.



Enplas can manufacture plastic microfluidic chips in the millions/year with consistent high quality! Quality assurance systems highly tailored to microfluidics manufacturing and cutting-edge equipment make this possible. Contact us to find out more!




Transitioning IVD Device Prototype Parts to Mass Production

Whether it’s a molecular diagnostic device for PCR or NGS, an immunoassay, or a single-cell analysis product, in vitro diagnostic (IVD) device engineers often struggle to preserve their IVD device performance while transitioning to a mass-producible design with lower material and production costs.

With more than 20 years of experience working with market-leading IVD manufacturers, here are some challenges Enplas has helped engineers overcome—and tips on how we’ve done it.

Challenge 1:

“How can we maintain our diagnostics component’s performance while switching material to meet mass-production price targets?”

Gearing up your design for mass production often means you must give up high-cost, high-functionality materials for more cost-effective ones. Transitions may include silicone to TPE or PDMS/glass/metal to plastics.

Silicone to TPE

For leak-free fluid sealing between components, thermoplastic elastomer (TPE) is a reliable and cost-effective material option. However, choosing the right TPE and the proper overmold design can drastically affect the sealing performance. Some TPEs are suitable for heat around or over 95°C for PCR, but some are not. Your material choice should consider other possible risks such as inflation, compression set, and hardening.

Glass to Plastics

Transparent plastics may be your choice for mass production consumables, but, unlike glass, autofluorescence may interfere with your detection.

With TPE and transparent plastics like COP, COC, PMMA, or other medical grade plastics such as PC and PP, our injection-molding engineers and suppliers have a wealth of knowledge in these materials. We will also provide guidance to help mitigate effects, including TPE compression set and transparent plastic autofluorescence.

Challenge 2:

“How can we safeguard fluid and droplet performance when adjusting the design for mass production?”

Designs tested with machined or 3D-printed prototypes require design adjustments to be effectively manufacturable by injection molding. However, for IVD device components or consumables, considerations to maintain or improve functionality (not just manufacturability) are critical.

Efficient Fluid Transfer

To efficiently transfer fluids and minimize reagent dead volumes, precise through-hole locations and strict part alignments are necessary. Enplas conducts thorough failure mode and effects analyses (FMEA), focusing on essential functions to mitigate misalignment risks. In addition, we can incorporate performance checks such as leak tests in your quality plan according to specific project needs.

Droplet Performance


Small DFM design changes can influence microfluidic channel performance (e.g., droplet generation). Enplas optimizes channel designs for mass production as we conduct DFM. Enplas identifies the channel optimization required to reduce droplet size variation or improve oil sample ratio for consistent droplet generation using proprietary data and software.

Challenge 3:

“How can we make smart investment choices when transitioning from prototype molds to mass-production molds?”

Final product validation requires a production-grade prototype mold to produce parts as close to those made with a mass-production mold as possible. The final production mold is an additional investment since prototypes with one or two cavities have different structures from a multi-cavity mass-production mold.

You might think, “Isn’t there a way to streamline the mold constructions to avoid fully investing in two completely separate sets of tooling and molds?”

The answer is “Yes.” If you are in the prototyping stage and eyeing transition to mass production, Enplas can create efficiencies in the process. For example, prototype molds can incorporate part of the upgrade required for mass production. In addition, proactive planning can make your prototype and mass-production mold construction faster and more cost-effective.

Challenge 4:

“How can we meet our aggressive launch date while dealing with unexpected product development issues?”

The ultimate challenge, of course, is that you must meet all the challenges listed above on a tight schedule. This pressure is becoming stronger as the need for rapid development of COVID-19 diagnostics has accelerated the development speed of all IVD products. A reliable manufacturing partner can guide you to the most efficient path to product launch and alleviate stress through fast and flexible problem-solving, preventing product quality issues, and avoiding unnecessary iteration.

Engineers should work with a mass-production supplier that understands and meets the needs of IVD product development by offering:

  • Absolute product quality while moving with speed
  • The engineering knowledge to mass produce complex, functional IVD components or consumables without performance variation
  • The long-term support often required for medical device development
  • Flexible responses to changing needs


If you’re transitioning your IVD device components or consumables from prototype to mass production, Enplas can make the process easier, smoother, and more cost efficient.

Enplas is responsive, transparent, and flexible throughout the prototyping and mass-production process, whether your need is urgent, unexpected, or part of a long-term vision.

Enplas provides problem-solving ideas, implements parts and tool designs that prevent future issues, and is there when you need support—no matter how long development takes.

For questions, contact Enplas today.

SURVEY RESULTS: COVID-19’s Impact on Users of Medical Injection-Molding Services

In fall 2020, Enplas surveyed users of medical injection-molding services to determine the impact of COVID-19 on their businesses. The respondents represented a variety of sizes, industries, and geographic locations.

COVID-19 has affected the operations of businesses that use medical injection-molding services. That much is obvious; no survey needs to be conducted to determine this. What the recent Enplas survey revealed, however, is in what ways.

By and large, the survey found that most customers (83%) of medical molding providers have seen their non-COVID-related projects postponed, deprioritized, or defunded. The majority (63%) have experienced longer production and development lead times as a result of COVID-19. And finally, many respondents (30%) expressed renewed difficulty procuring parts and raw materials as suppliers become overburdened or shutter altogether.

The quantitative data was reinforced by the qualitative results. When asked about “services or special considerations [respondents] would like to see from medical injection-molding service providers to accommodate…COVID-19,” many businesses offered responses such as:

  • “Better communication about product lead times”
  • “Transparency and visibility about the impacts on schedule and delivery”
  • “[Help] finding alternative raw materials that are readily available to avoid delay”

In today’s pandemic environment, situations change quickly. This remains true for developers of injection-molded medical products, especially those developing COVID-19-related diagnostics. The desire to get these important products out the door and into the hands of those that need them has been amplified over the past year. As the Enplas survey reveals, the challenges in doing so have only grown as well.

Enplas understands customers in the medical field. While we also experience increased industry demand, we continually strive to be flexible and transparent with our customers. No business wants to hear that their project has been delayed at the last minute. That’s why we provide consistent, proactive communication and updates throughout the entire development and production process. We provide timeline estimates at the start of every project, and if there are any unforeseen delays, we inform you as soon as possible—so there’s plenty of time to adjust and plan accordingly.

Unfortunately, many businesses are experiencing difficulties with procuring parts and raw materials due to the pressure COVID-19 has placed on supply chains. In this situation, Enplas supports customers by finding ways to source the materials they need and helping to find alternative materials if those are not currently available. Our aim is to reduce delays in your project to the best of our ability.

Enplas maintains an agile global supply chain to support our customers’ needs worldwide. While our U.S. sites can handle the production of millions of parts, our network of factories across the U.S. and Asia helps ensure that our clients receive their products when they need them—all while working with local engineers. For more information on how our global supply chain can support your needs, click here.

If you’re looking to quickly ramp up production of your plastic medical components, it’s important to work with an experienced injection molder with a global supply chain and commitment to transparent client communication. With experience in developing and producing plastic medical components in quantities of hundreds to millions, Enplas can assist you with your new or existing product to ensure efficient manufacturing costs, speed, and consistent quality parts production.

For more information, contact us today.

This survey was conducted in partnership with Alphasights.

Plan Ahead to Get Your COVID-19 Diagnostic to Market Fast

In the current era of COVID-19, many diagnostic device developers are looking for ways to get their products to market fast. They are striving to fill one of today’s most important healthcare needs: new devices and technologies to help fight the pandemic.

Still, many developers operate under the mistaken assumption that once the technology is finalized, everything else will fall into place. This couldn’t be further from the truth. In fact, once the technology is done, a long road remains—one consisting of regulatory hurdles, manufacturing concerns, shipping, marketing, and more.

Bottom line: it benefits COVID-19 diagnostics developers— and in fact, medical device developers of all types—to plan ahead and start early.

One of the most beneficial steps diagnostic developers can take is get a manufacturer onboard early, preferably in the development phase. What if you’re not at that stage yet? Fortunately, the National Institutes of Health (NIH) and the U.S. Food and Drug Administration (FDA) recently took actions to help get diagnostics to market faster.

The NIH RADx Program

The NIH, in collaboration with other organizations such as CDC and Biomedical Advanced Research and Development Authority (BARDA), recently launched the Rapid Acceleration of Diagnostics (RADx) program. This program is intended to accelerate innovation in the “development, commercialization, and implementation of technologies for COVID-19 testing.” One component of RADx is a funding opportunity to assist organizations developing COVID-19-related diagnostics. Another component provides assistance to developers in scaling up their technologies and increasing their performance. You can find more information about the RADx program here.


On February 4, 2020, the U.S. Department of Health and Human Services (HHS) determined that the coronavirus represents a “public health emergency that has a significant potential to affect national security or the health and security of United States citizens living abroad.” Subsequently, FDA (an agency of the HHS) authorized the emergency use of in vitro diagnostics and other specifically defined medical products and devices for the detection and/or diagnosis of COVID-19. This Emergency Use Authorization (EUA) allows for the use of “unapproved medical products, or unapproved uses of approved medical products, to diagnose, treat, or prevent serious or life-threatening diseases when certain criteria are met, including that there are no adequate, approved, and available alternatives.”

In essence, an EUA officially expedites the process to quickly get medical products that fulfill urgent needs into the hands of professionals and the public during healthcare emergencies. It’s important to note that products approved under an EUA are only authorized for use in specific circumstances and during a particular emergency period. When those conditions end, so too does the EUA declaration, and as a result all the EUAs issued based on that declaration will be terminated. You can find more information on the EUA here.

NOTE: At the time of this article’s writing, developers may not be required to obtain premarket FDA review of their laboratory developed tests (LDT).


Say you have funding for your COVID-19 diagnostic device development program. Now what? Hopefully, you have planned ahead and have already begun working with a manufacturing partner. As stated before, getting a manufacturer onboard with your device early can help diagnostics programs be more successful, and make the ramp up to mass manufacturing faster and easier.

Ideally, developers should begin working with manufacturing partners in the development stage. Some designs, depending on subtle directions or locations of features, may not be mass manufacturable or may require complex methods with higher costs. This becomes a problem if the product is brought to the manufacturer after the designs are “locked in.” Your manufacturing partner can work with your engineering team on design development to make your designs manufacturable, and/or with a more efficient manufacturing method that could save costs. Addressing Design for Manufacturability (DFM) items upfront could save a lot of development time compared to finding (possibly expensive) work-arounds later with little room for adjustment.

The partner you select should have the expertise required to manufacture your device to your unique specifications. A manufacturing partner should also have knowledge and experience in quality assurance and regulatory requirements. They can help ensure that it complies with applicable standards. For medical products, the manufacturer should be well versed in process validation to ensure efficient production of your quality parts.

Choosing the right manufacturing partner is also critical to ensuring a continued supply of your devices with the high standards you need. Inexpensive molds and tools may be able to make good parts to specification at the beginning of their tool life, but we have heard many horror stories in which customers begin receiving defunct parts after working with a budget manufacturer, and being unable to get any improvement plans or accountability from it. Choosing a trusted manufacturing partner is the best thing you can do to save costs, time, and quality troubles in the long run.


Often, a failure of design is not the biggest challenge diagnostic device developers face. Rather, it is simply the failure to plan ahead. Successfully getting a new product into mass production, and doing it well—on time, at the correct volume, with high quality, and cost effectively—is not easy.

Getting it right the first time is important. COVID-19 diagnostic device developers that plan ahead and begin working with a manufacturing partner early will launch their products faster and more effectively. There’s an old adage that says, “Failing to plan is planning to fail.” By planning early, developers can put themselves on the path to success.

With over 20 years of satisfied customers, Enplas Life Tech is the leading single-source manufacturer of high-quality custom plastics parts for global OEMs in the medical, biotech, pharmaceutical, and life science industries. For more information about Enplas Life Tech and how we can help you with your COVID-19 diagnostics projection, click here.

From Metal to Plastic, Silicone to TPE: Cut Cost, Enhance Performance

Learn how Enplas’s engineering and manufacturing expertise helped a major pharmaceutical OEM convert a test instrument component from metal and silicone to rigid plastic and TPE, enhancing the component’s functionality and usability, and reducing overall manufacturing cost.


Enplas was approached by a global pharmaceutical OEM to manufacture a four-channel pipette air displacement device it used in biotech test instruments. The device consisted of a brass body, four stainless steel tubes, and four silicone molded seals. The goal was to redesign this whole assembly into a single plastic part.

The final single plastic part consisted of overmolded TPE seals and a plastic substrate. This redesign enhanced the device’s functionality and usability while significantly reducing its overall manufacturing cost. The project combined two of Enplas’s strengths: expertise in manufacturing thermoplastic fluid seals and a long history of helping customers convert metal parts to plastic.

Metal to Plastics Conversion



The goals of the redesign were:

  • To reduce the cost of the device’s materials
  • To eliminate the need for assembly and reduce the number of fixtures used in the assembly
  • To eliminate the risk of damage from sub-assembly (i.e., components damaging each other during assembly)
  • To eliminate recurring maintenance issues in normal operation (e.g., sub-assembled components loosening slightly)


The redesigned device needed to maintain the same precise dimensions of the original. In addition, the device’s elastomer seals need to be consistently air-tight against its inlet ports and maintain a product life of at least 1,000 cycles of pressurization.


Enplas began this project by understanding the original device’s performance requirements and assembly consideration with surrounding components. This enabled Enplas to recommend the best materials to use (both elastomer and rigid plastics) to meet the client’s goals. To ensure reliable sealing, material considerations included hardness, compression set, and chemical bonding characteristics.

Enplas also analyzed the physical design of the elastomer fluid seal to ensure secure contact with the consumable. The size and shape of the device’s contact surfaces is critical to ensure its air-tight sealing performance when pressurized against inlet ports.

The practice of Design-for-Manufacturability (DFM) was adhered to throughout the project to ensure the consistent and efficient production of quality parts for both injection molding and assembly with other components.

Finally, Enplas provided quality manufacturing services for the redesigned device, which included injection molding the rigid plastics and overmolding the TPE seals. All manufacturing at Enplas Life Tech undergoes our rigorous process validation practice to ensure quality and consistency.


Enplas successfully manufactured the redesigned component and exceeded the original device’s performance in several critical areas:

  • The device’s separate metal parts were replaced with a single component made of injection-molded plastic substrate. The device’s silicone seals were replaced with overmolded thermoplastic elastomer (TPE) seals. This resulted in over 70% cost savings due to lower material cost and elimination of manual assembly.
  • The device was required to perform up to at least 1,000 cycles. The redesigned device achieved over 7,000 cycles during endurance and functional tests without leaking.
  • Sub-assembly damage has been eliminated.
  • The new device exhibits no quality or maintenance issues during manufacture or operation. Recurring maintenance issues in normal operation have been eliminated.

For product conversions or enhancement projects, it is important to engage an expert manufacturer with a reliable engineering team that can recommend the best materials and manufacturable designs to achieve your performance goals, ensure reliable quality, and maximize manufacturing efficiency to reduce costs. Contact Enplas early in your design process to allow necessary modification to achieve best results like the above. Contact us now for your next project!

To learn more about whether silicone or thermoplastic elastomers (TPE) might work better for your project, download our comparison sheet.

Design for Manufacturability (DFM): The Basics

If you are part of a product development team working on a product that may reach millions of parts, or are a growing start-up about to ramp up production volume, this article is a refresher on basic design for manufacturability, or DFM. At Enplas Life Tech, we believe that DFM is a collaborative process between our customers to enhance their original part designs. Read on to learn how injection molding engineers can help ensure your components are manufacturable and cost-effective at scale.

Design for manufacturability is the process of designing products to facilitate the manufacturing of components. DFM is especially critical for mass produced components and assemblies. It safeguards quality, it saves time, it saves money—and most importantly, it can prevent potential problems down the road.

Although there are many dimensions to DFM, the most basic goals ensure that:

  • It’s physically possible to manufacture your part, and
  • The manufacturing process is streamlined to be simple, efficient, and robust.

Basic Design for Manufacturability for Injection Molding

Due to the nature of the injection molding process, there are guidelines to follow when designing components. In injection molding, you have two molds enclosing a cavity that is filled with plastics to form the component. After the heated liquid material is injected into the cavity, cooled, and solidified into the part, the molds separate to eject the product. (This is a different process from 3D printing, a popular prototyping process. A part that can be 3D printed may be impossible to be produce via injection molding.)

Injection Molding

Below are a small portion of the many basic DFM considerations required to ensure that the final part design is possible to manufacture. Without proper consideration, the part may have defects or be vulnerable to breaking. These considerations include:

  • Undercut: A simple mold like the one shown in Figure 1 cannot open when there is an undercut. Certain undercut features could still be injection molded with special tooling, which would make the tooling more complex and costlier.
  • Draft: To ensure the molds open smoothly, products need draft. A product’s draft angle is a slant that is applied to each side of an injection molded part. The angle is positioned to run toward the direction of a mold’s pull and parting line; this helps to release the part from the mold. Draft considerations are important to meet your quality standards. Without it, major problems can arise that increase production time and cost.
  • Wall Thickness: Something seemingly as simple as wall thickness can have a remarkable effect on a product’s success. For instance, thinner walls require less material and cool faster. This reduces a mold’s cycle time (increasing the number of units that can be made per period) and input costs. But go too thin, and the product becomes brittle and unreliable. Too thick? Your process is not optimized. Another major consideration is the uniformity of wall thickness; a lack thereof can cause weakness and unsightly “sink marks.” Optimizing wall thickness is a basic—yet critical—consideration for your injection-molded product.
  • Rib Ratios: Walls that are thicker or non-uniform by necessity of design can sometimes cause problems. To counteract these issues, ribs are used. Ribs are thin structures that add support and rigidity to injection-molded parts. This solution, however, can cause problems of its own. To prevent these problems, rib design must adhere to certain proportions. For example, if your product’s ribs are too tall, breakage can occur during use or during ejection from the mold. Rib ratio must be carefully planned and evaluated for success.

Design for Manufacturability for Assembly and Overall Product Performance

In addition to ensuring that your part is injection moldable, other DFM considerations contribute to the function or overall assembly process of the product. For example, the addition of measured features could make the assembly process easier and less costly further down the road. Combining two components in one is another way to simplify overall assembly. Read our blog on advanced DFM for more information about DFM that enhances product performance and simplifies assembly at the same time.

Failure Mode and Effects Analysis (FMEA)

Any basic DFM done well should also include a failure mode and effects analysis (FMEA). This is the process of identifying the risk of possible modes of failures while a product is still in the development phase, and the development of measures to mitigate those risks. FMEA is a critical part of the initial phase of process validation for our projects.

At Enplas Life Tech, we believe design for manufacturability is a way to solve difficult engineering challenges collaboratively with our customers. DFM enhances component designs by improving product manufacturability.  Enplas Life Tech has a long history of successful collaborations with engineers at market-leading, global OEMs and innovative start-ups alike, in the medical, diagnostic, and biotech industries. Have a design ready for production? Contact us.

Design Development Beyond Basic DFM for Product Performance

If you’re reading this article, you’re probably already aware of the basics of design for manufacturability (DFM): the process of designing products to facilitate their manufacturing.

However, a more product performance focused DFM does not simply make your product moldable: it can also enhance your product’s value in terms of its function, quality, supply stability, and manufacturing cost. We could even call this “Design for Functionality”.

Unlike many manufacturers, Enplas Life Tech goes beyond the basics to offer this advanced DFM when we see opportunities to help. Our customers—innovative medical industry market leaders—tell us again and again how they appreciate this customer-centric practice. 

For example, many companies approach Enplas Life Tech for the manufacture of elastomer fluid seals for diagnostic or medical devices. Given the intricacy in shapes and functions of fluid seals, the end product’s performance and quality may diverge greatly depending on whether it went through only basic thoughts of DFM, or a more rigorous, advanced DFM process.

The below image is a sample of an elastomer fluid seal between a fluid inlet (pipette) and a microfluidic chip. Customers’ original designs often come with two or more sealing ports with separate elastomer tips, each to be assembled as a secondary operation after injection molding. (See Figure 1 [note: this is a hypothetical design].)

Fig 1a. Pipette, interface with elastomer fluid seals, and microfluidic chip

Fig 1b.Two fluid sealing ports, two separate parts for each port

Conducting basic DFM would be sufficient to ensure that this design is compatible with all injection molding processes (e.g., no undercuts, appropriate draft, and material being compatible with the dimensions and wall thickness). 

After discussing the project with the customer, however, we develop a deeper understanding of their priorities for the product’s application: the seal must stay in place to avoid any leakage. Our goal is always to support our customers in achieving the best possible product value. Therefore, we might suggest the following change (see Figure 2):

Fig 2. Two sealing ports, one integrated part sealing both ports

This change in the design created a path (an “internal runner”) that enabled the thermoplastic elastomer to flow inside the rigid plastic and connect the two sealing ports. This change provides multiple benefits:

1) Function: Enhancing Fluid Seal Bond Strength

  • The internal runner performs as though it is “bolting down” the elastomer into the rigid plastic as opposed to simply being glued externally. This makes it significantly stronger and prevents it from peeling off. 
  • This uses a method called “overmolding. Overmolding takes advantage of the thermoplastic elastomers’ characteristic to chemically bond to rigid plastic surfaces. This also enhances seal strength and avoids the risk of the seal peeling off, decreasing the possibility of leakage or reagent loss.

2) Time and Cost: Eliminate Assembly Process and Reduce Lead Time to Lower Cost

  • By overmolding the part, the injection molding process alone will completely attach the two materials. There will be no need for additional assembly processes or adhesives—hence no problems from assembly or adhesives during mass production.
  • By combining the two tips into one elastomer seal, the mold/tools can be simplified. This also contributes to reducing cost.

Material choice is a significant consideration in DFM. In the past, Enplas Life Tech has suggested using a different type of elastomer, even though the original choice may have been sufficient to make the part. In this particular case, we recommend materials that are able to fill in molds more quickly due to higher viscosity. In these cases, the change in materials has improved the stability of production quality, avoiding chance defects. 

In order to suggest these changes, the injection molder must be well-versed in the characteristics of both rigid plastics and thermoplastic elastomers; have the sufficient expertise to build tools that can achieve the desired precision design; and, most importantly, have the dedication to work with customers and their complex requirements until the right solution is found. 

At Enplas Life Tech, we believe DFM is a way to solve difficult engineering challenges collaboratively with our customers to enhance component designs, improving product quality and performance. This makes life easy for all stakeholders: from our customers’ component design engineers and quality managers, to OEM customer production and assembly lines.

Enplas Life Tech has a long history of successful collaborations with engineers at market-leading global OEMs in the medical, diagnostic, and biotech industries. Have a design ready for mass production? Contact us

Process Validation

If you’re a market-leading life sciences company searching for the right quality plastic parts manufacturer or custom manufacturing services provider, you already know how difficult it can be. Just trying to find a qualified provider you can trust can be time intensive and, well… frustrating.

At Enplas Life Tech, we know that trust is one of the most important services we can offer. We understand that your products’ success relies on the service providers you choose to trust.

That’s why Enplas Life Tech has an established quality control procedure built on proper industry-standard validation procedures: to statistically ensure that each part coming out of the line will fall within strictly-set standards for your project.

Precision quality parts from Enplas Life Tech are a trusted, reliable choice for your important diagnostic and medical devices. We know that your component production must continue without interruption. Therefore, we created a rigorous validation process that will enable us to provide you with an uninterrupted supply of the components critical to the shipment of your products that may ramp up volume over time.

Enplas Life Tech complies with the increased requirements of documentation and traceability in the medical industry. Our four-part process—DQ, IQ, OQ, and PQ—is the standard for validation and quality assurance in the medical/biotech industry. Enplas Life Tech took the basics of this standard process and added other procedures we consider necessary to have a truly rigorously validation process. These validation steps establish documented evidence of a high degree of certainty that the manufacturing process will consistently yield a product of predetermined quality. Enplas Life Tech records each step of the process and provides our customers with complete documentation in the form of the “Process Validation Protocol (PVP).”

Our validation process begins with the DQ (design qualification) stage. In this stage, our priority is to properly understand our customer’s unique, specific requirements and expectations. This includes areas such as production volume (e.g., including whether the production volumes might remain stable or increase with time, and resulting in decisions such as number of cavities), tool life, required levels of tolerance, and the minimum-required “CpK value”—a value that statistically indicates the capability and likelihood of the produced part coming in at required specifications. This information is used to determine how to build and set up the molds (e.g., what type of steel, which press, what support equipment is needed, cost, how many operators). All of the following processes—IQ, OQ, and PQ—are conducted to achieve the goals set in DQ. 

In addition, a failure mode and effects analysis (FMEA) is conducted as part of the design-for-manufacturability (DFM) process to minimize failure risk for critical functions or dimensions. 

The second stage is the IQ (installation qualification) stage. This stage is where the tools are built and evaluated, all production related equipment is set up, and various injection molding parameters are tested to determine a safe range of settings. It confirms that the tools are built to meet all inputs from the DQ stage and that the molding process is appropriately set up to begin producing sample parts with the injection molding machines. 

This stage marks the beginning of “scientific molding”: a practice to identify a range of injection molding parameters that would achieve the highest yield of precise parts. In other words, testing the limits of parameters to retain highest levels of quality in the products’ precision and dimension while running the presses in the most efficient manner. In the scientific molding process, data is collected from various studies (e.g., gate seal, cavity balance, back pressure, and melt flow) as outputs to create a “process window”—a general range of statistically-tested process parameters that produce products within the required tolerances. 

Other studies (such as the cooling study, used to determine the smallest amount of time required for the dimensions to become most stable) are also conducted.

The OQ (operation qualification) stage further refines the parameters to achieve certain operational performance requirements. OQ takes the data from the previous stages further: it obtains objective evidence that a defined, optimal process window allows the consistent production of acceptable products. A design of experiments (DOE) study is conducted, in which software statistically calculates many process variables to identify the optimal ranges. Following that, a full-dimension, first-article inspection derived from a set number of sample parts is conducted and the CpK is measured. If the CpK does not meet the initial goal set in the DQ stage, improvement plans are created and implemented.

PQ (performance qualification), the final stage, challenges the equipment similar to the OQ phase, but now does so under load. Finally, longer-run trials are conducted to confirm that key dimensions are maintained under a longer production period. Another first-article inspection and capability study are conducted on samples. The process is then officially validated to ensure it meets the customer inputs provided at the DQ stage. The degree to how much time and effort we devote to the PQ stage depends on customer requirements. We are happy to conduct the right level of validation to meet your specific needs.

Is your life sciences company searching for a quality plastic parts manufacturer or custom manufacturing services provider? Consider Enplas Life Tech’s engineering and design services and trusted validation process. Contact us today to learn more.

Want more proof of our dedication to product performance and quality? Download our TPE case study, “Life Science Diagnostic Device Development: Challenges and Solutions for Fluid Interfaces.”