For the last several years, we’ve been asking questions and getting answers — which has led to even more questions. So now, we’re looking for more answers. Let me explain.
In a February post, I talked about the significant challenges rapidly evolving technology poses — especially for small and medium-sized manufacturers (SMMs). I also described Shift, a program designed to help SMMs think through these challenges. As a first step in the program, the SMM completes a business assessment that evaluates their key risks and capacity for innovation. Through this business assessment, we ask questions. And we get answers.
Since Shift’s 2017 launch, we’ve surveyed almost 100 SMMs on the topics of strategy, technology, and business performance. And we’ve found that SMMs consistently rank process and technology innovation as their #1 area with the greatest room for improvement. A follow-up question that asks about the biggest barriers to technology adoption reveals, most significantly, that SMMs struggle with the gap between their existing workforce and the skills required to leverage process and technology innovations.
At EWI, we understand. I spoke to the issue, in part, in a late 2019 post — and prior to the COVID-19 pandemic, we had launched several new training initiatives to help bridge the gap.
With the advent of the pandemic, however, most of our efforts had to be shelved. We’ve had to re-examine, re-think, and re-imagine our training offerings, asking: What training can and should we provide, and how do we best provide it in this new environment?…
With
automation, machine vision, and other manufacturing technologies, mass-produced
consumer products are now more consistent and economical than ever. Why, then, do most new products fail in the
marketplace?
There are many reasons — overpricing, development delays, product flaws — all of which are foreseeable. As engineers and scientists, we at EWI have seen plenty of preventable product flaws. Understanding the interdependencies of materials, processing, design, and cost can help you avoid the pitfalls other manufacturers have suffered.
The EWI Guide to Designing Consumer Products for Manufacturability explains these interdependencies as they pertain to joining products made of plastics. The insights and case studies shared can help you shorten process development time and reduce the effort required to put successful new products in the hands of your customers.
You are invited to download this guide — compliments of EWI — by completing the form below.
Yes, please send the EWI Guide to Designing Consumer Products for Manufacturabilityto:
Do you want to improve the manufacturability of your products? EWI can help. Contact us at 614.688.5152 or [email protected].
Polymers are more alive than you may realize. There are
molecules within them that wiggle, others that move from here to there, and
finally some that permeate all the way through. Polymer properties change as
all this motion is occurring. When this is not understood or anticipated,
products fail. The good news is that if we consider the product’s environment,
we can choose a material that will ensure your product lasts.
Small gas molecules, such as hydrogen, oxygen, and even
water vapor are constantly diffusing through polymers. They are small enough
fit in between the amorphous polymer backbone chains and can cause issues for real
life products. Likewise, there are additives, such as plasticizers, that are
mobile and move through polymer.
Plasticizers diffuse out of the polymer and
leave the material less elastic and more brittle. For example, that new car
smell is plasticizers leaving your dashboard and making it more vulnerable to
cracking.
Oxygen permeates through packaging and reduces
shelf life, thus spoiling food contained within. Oxygen can also leak through
seals in packaging; an EWI spin-off, UltraThinSeal, has found that ultrasonic
seals for potato chip bags allow less oxygen than heat seals, see Figure 1.
Hydrogen
absorbs into elastomers seals for pumps and storage containers which can cause
catastrophic failure during decompression due to supersaturation and foaming.
Water vapor (humidity) permeates into packaging
and cakes dry powder products like sugar or changes the composition of fluids
like brake fluid.
Water vapor permeates out of packaging leaving
liquid products with decreased volume and/or increased concentration in liquid
medicines.
Water vapor absorbs into a plastic that is
ultrasonically welded leading to voids and low strength.
So, barrier properties are important for everyday
applications – but how do these things happen? Gases move in or out of polymers
based on pressure or concentration gradients. Polymers attract like gas
molecules, so a polar group on polymer chain will absorb more water than a
non-polar group. For example, Nylon has polar side groups and it absorbs a
relatively high percentage of water humidity from the atmosphere, while high
density polyethylene (HDPE) is non-polar and allows very little (0.01%). Therefore,
HDPE has a lower water vapor transmission rate. Barrier properties can be tuned
to meet the needs for the product.
Crystallinity and fillers in the polymer effect gas molecule
permeability. Spherulites are crystalline arrangements of polymer backbone
molecules that pack much tighter than the amorphous regions. The tight packing excludes
gas molecules from entering. Similarly, fillers such as glass and calcium
carbonate also block molecules. The gas molecules must find a circuitous path
around the obstacles in the polymer to permeate through. So, polymers with high
crystallinity or filler content typically absorb less gas and have lower
permeation rates.
Permeation rates of gases through polymers can be measured.
One of the most popular and accurate instruments is a permeation analyzer. For
this test, a film of the material is clamped into the instrument. One side of
the film is exposed to the gas of interest (e.g. oxygen or water) and the other
side is flushed with an inert gas (nitrogen or argon). There is a detector on
the flush side to determine when the gas of interest permeates through the
material. Solubility, diffusivity, and permeability can all be determined from
this measurement. The permeation rate is typically linearly dependent on the
gas concentration and exponentially dependent on temperature.
The higher the gas solubility in the polymer, the more it
increases the void space and thus allows greater polymer chain movement. This
can relieve molded-in stress, and in extreme cases deform parts. Higher
absorption also allows for molecules, such as plasticizers, to diffuse within
the polymer, combine and form micro-regions with much different properties.
These plasticizers can also diffuse all the way to the polymer surface and
render it stiffer and more brittle.
Overall, barrier properties must be considered when choosing
a material for a product. The product’s environment and expected lifetime are
used along with its barrier properties to make predictions of how much gas will
absorb and permeate through the polymer. This can give you a clear picture of
the risk of product failure during its intended lifetime.
Are you experiencing barrier diffusion issues with your
plastic products? EWI can help. Contact Jeff Ellis at [email protected] or 614.688.5114 to learn more.
Interest in electromobility solutions for aviation these days is, ahem, skyrocketing, especially for propulsion systems geared toward electric vehicle take-off and landing(eVTOL) technology.
With applications ranging from drones to unmanned aerial systems already in play, passenger vehicles are set to be the next commercial application.
EWI has long been an innovator in vehicle electrification technology for the automotive and rail industries. With decades of experience in the joining and inspection of batteries, drivetrains, and complex wiring systems, we have both the insights and resources to help manufacturers develop eVTOL technology and advance it toward product implementation.
In response to the increased demand in eVTOL, EWI is reaching out to manufacturers in aerospace to identify their biggest electrification challenges, and to apply its expertise toward developing technical solutions for implementation. To best assess the needs of the industry, we are asking OEMs and suppliers to share some basic information. We invite you to answer the following two questions:
The findings of this survey will be shared
with all respondents, but individual company information will remain anonymous.
In addition, to thank you for your participation, we will
send you our new guide, Challenges and Opportunities in Electromobility. Your
guide will be delivered upon receipt of your response.
If you have questions about EWI’s eVTOL initiative or other
work in e-mobility technology, contact Randy Friedlander at [email protected].
Both material type and thickness can affect formability modeling, which is based, in part, on forming limit diagrams(FLDs). When the EWI forming lab experienced edge cracking and distortion with thin, nickel-based super alloy, it decided to test the material against the ISO standard for FLDs. Would the standard hold up?
EWI Applications Engineer Laura Zoller has written about the study and its results in Effects of Edge Quality in Creating Reliable Forming Limit Diagrams.
You are invited to download this paper, at no charge, by completing the form on this page.
If you would like to learn more about this project or other formability testing at EWI, contact Laura Zoller at [email protected].
Complete this form to download the paper:
To view the paper, please submit the form above.
To speak to an EWI expert about a project, call 614.688.5152 or click here.
EWI recently completed a study which demonstrated the suitability of tandem/twin gas-metal arc welding for directed energy deposit (DED). Twin-wire pulsed technology offers a superior deposition rate, excellent feature fairness, and is tolerant to contact-tip-to-work variations. Because it is omni-directional with respect to travel direction and torchwire orientation, the process is compatible with robotic computer-aided manufacturing software.
This work is discussed in High Deposition GMA Technology for Large-scale Additive Manufacturing, a paper by EWI associates Dennis Harwig and Michael Carney.
You are invited to download this paper, at no charge, by
completing the form on this page.
If you would like to learn more about this project and EWI’s
other work in DED technology, contact Dennis Harwig at [email protected].
Complete this form to download the paper:
To view the paper, please submit the form above.
To speak to an EWI expert about a project, call 614.688.5152 or click here.
Choosing materials for a new medical device is not a trivial
task; without proper care, costly late-stage issues can derail an entire
program. Material failures for medical devices are common and costly, 30-40% of
FDA recalls are due to material issues.1 These issues may include compatibility
of the fluid formulation with contacting materials, biocompatibility of the
materials with the patient, reduced fracture resistance, mechanical properties
degradation, undesired aesthetic changes, and the effects of long term stress
or stain. These failures and others are presented in Figure 1.
To avoid these, you should incorporate a comprehensive materials selection and
testing protocol early into the product design cycle.
Figure 1. Material failure fishbone diagram
Materials selection begins with writing a requirements
document that incorporates the input from both the engineering team and the
human factors team to ensure that the device will function and meet the user’s
expectations. The engineering team must consider all conditions that the
materials will experience from resin compounding, shipping, assembly/joining,
storage, use, and disposal, while the human factors team must consider how
people will interact with the device. These include considerations of human,
mechanical, chemical, and thermal stresses exerted on the device, such as
gripping the device, cleaning it with harsh sanitizing chemicals, or leaving it
in a hot car.
Sometimes device manufactures, design firms, and injection
molders have preferred polymer vendors. While many times their vendor has the
best material for the application, sometimes they do not. This is where an unbiased
third-party review of device materials can give a broader perspective of which
polymers are better suited to meet all the requirements for the device.
The requirements document and the Failure Modes and Effects
Analysis (FMEA) document are then used along with material datasheets to select
materials that will be suitable for all conditions the product will encounter.
There is always a gap between the requirements and the data sheet information
because resin manufacturers cannot test their polymers under all conditions.
This is where additional testing under real-world conditions must be performed
to challenge the viability of the top material candidates.
All concerns for product viability must be tested to best
mitigate failure risk. Polymer testing requires considerations under actual use
conditions. Examples of this include:
Measuring fluid absorption into the polymer and
its corresponding effect on mechanical properties by Instron testing
Determining the efficacy of the fluid in the
device after contact with materials by measuring its remaining activity
Assessing biocompatibility via ISO 10993 testing
Measuring mechanical properties (Young’s
modulus, ultimate tensile strength, strain at break, storage/loss modulus, tan
delta etc.) at the highest and lowest temperatures the device will experience
by Instron and dynamic mechanical analysis (DMA) testing
Consideration of joining applications during
assembly and the material related properties necessary to their success, such
as melt flow index of dissimilar polymers joining by ultrasonic welding or
energy absorption of the materials for laser transmission through welding
Monitoring environmental stress-cracking while
exposed to liquid formulation or cleaners by a static bend and soak test
Estimating long term stress relaxation or creep
using time-temperature superposition (TTS) from data obtained on a dynamic
mechanical analyzer (DMA)
Implementing accelerated aging of whole devices,
followed by inspection and testing, to understand system level issues
These tests will reduce the risk for both product failures
in late stage development and costly recalls after product launch. Despite the
added time and cost, imposing the discipline of these analyses will help avoid
embarrassing and costly recalls later. To realize the full cost savings
potential this material selection protocol must be implemented early in the product
development.
An inter-industry, universally accessible repository of additive manufacturing information is now in the works.
The ASTM AM Center of Excellence is helping to drive a community effort to develop an AM data ecosystem that will include a common data dictionary, a common data exchange format, and an automated method for uploading new data into the system.
EWI Applications Engineer Luke Mohr has written Working Towards a Full AM Data Ecosystem which describes this project. You are invited to download this paper, free of charge, by completing the form on this page.
Complete this form to download the paper:
To view the paper, please submit the form above.
To speak to an EWI expert about a project, call 614.688.5152 or click here.
Ultrasonic metal welding is an excellent process for the joining of dissimilar metals in electric vehicle batteries. The ability to monitor the joint during the welding processes is important for identifying faulty welds and avoiding product failure.
Recently, EWI has made some important progress in in-situ
monitoring for ultrasonic metal welding. Applications engineer Lindsey
Lindamood has written Developments in Ultrasonic Metal Welding Monitoring to
discuss this work.
You are invited to download this paper, with our
compliments, by completing the form on this page.
Complete this form to download the paper:
To view the paper, please submit the form above.
To speak to an EWI expert about a project, call 614.688.5152 or click here.
