01 Aug Engineering Plastics
JD Technologies, LLC Application Note White Paper
08 August 2017
Eric Gustafson, Sales Engineer
Engineering Plastics
The mention of using Aluminum Alloys or other metals for ruggedness and durability is no longer the norm. What we know of today as engineering plastics or engineered plastics have very good material properties. Perhaps not quite the same as Aluminum, but for the right design scenario they can be leveraged to replace aluminum and other metals.
The invention of Nylon in the late 1930s ushered in a new age of more robust and durable plastics. Here is an article about Nylon and its inventor Wallace Carothers at the American Chemical Society.
The new engineering plastics that followed helped change industries and the look and feel of many of the devices in our homes and offices. These plastics are all around us and are widely used today for their superior advantages over metals in some instances. These plastics are known commonly as engineering plastics and high performance engineering plastics.
These materials include:
Polyamide (Nylon) – A well known material but not as well known is that thousands of options are available in this material and some blends can offer significant advantages over the base material.
Polyimide (Kapton & Other names) – Very high melting point, can be used for coating cables and wires and high temperature applications. High Tensile Strength
Polyamide Imide (Torlon) – Expensive but has superior strength properties over most other engineering plastics.
Polyetherimide (Ultem) – Originally invented in the late 70s at GE Plastics as the “ultimate engineering material.” Can be mixed with glass or other fillers to get very good properties.
Polycarbonate (Lexan) – Very versatile, excellent for bullet proof glass, optics, molded parts, machined parts and many other applications.
ABS & ABS blends – Used in automotive industries, resistant to corrosive materials, very high impact strength.
Liquid Crystal Polymer (Kevlar, Vectran) – Very versatile, highly temperature and fire resistant, can be used for a wide variety of applications, ovens, motors, electronics housings, electronics connectors, bullet proof vests, bullet proof materials for military vehicles.
PEEK & PEK (polyetheretherketone) (Polyetherketone) – Can achieve very high strengths with respect to plastic materials, can be modified with glass fillers to achieve Coefficients of Thermal Expansion on the same order of magnitude of some metals.
Acetal (Delrin) – Comes in “homopolymer” or “copolymer” each have distinct advantages. These materials are very economical in terms of cost, machinability and have very good strength properties.
Advantages:
- Plastic is 40% to 60% the density of Aluminum 6061-T6 Alloy and as much as 1/6th that of steel
- Using fillers such as glass fibers or carbon nanotubes, significant increases over the base material can be made in strength and rigidity
- Significantly more pliable, where some metals might fracture, plastics may bend but will not completely fracture or tear apart adding some level of safety in extreme conditions that might cause failure
- Strength can approach that of some lower strength Aluminum Alloys and Diecast aluminum
- Has higher energy absorption than metals so may perform better in high vibration environments or in applications where shock loads are expected as a part of normal operation
- Can be machined or injection molded or 3D printed for relatively low manufacturing costs
- Typically less susceptible to chemical agents
- Typically do not corrode
Risks and disadvantages:
- Significantly lower thermal conductivity
- Lower Surface Hardness
- Relative Lower strength and modulus of elasticity that is present in the higher strength alloys of Aluminum, Steel, Titanium, Copper, etc.
- Setup and molding costs can be expensive (but at high quantity volumes these costs get averaged out)
- Can be susceptible to weakened properties when under strain and exposed to liquids, acids and caustic agents
- Typically lower melting point than metals
More Resources:
Some advanced research journals often have open access journal articles and there are more completely open access journals out there.
Matweb is a good database for material properties and is free.
About JD Technologies, LLC
JD Technologies LLC provides premium sales and marketing services to a group of high quality, complementary manufacturers of engineered services and products who serve the aerospace, military & defense, industrial, and medical industries. They develop long term relationships with key customers who value the consultative style of selling and who wish to interface with sales professionals of high integrity. Their approach is to use proven consultative selling techniques. Consultative selling is a collaborative process that leads customers/prospects through an analysis of their current situation to a resulting improvement. For more information on JD Technologies, LLC, their products, services and their consultative selling methodology, visit www.jdtechsales.com.
About Automation Plastics Corporation
Automation Plastics Corporation (APC) boasts a list of Fortune 500 clientele with niches in the medical, aerospace, appliance, construction, automotive and consumer products industries. ISO 9001:2008 registered, APC and our employees are dedicated to exceeding customer expectations and enhancing product quality. Our 50,000 square foot facility is located near Cleveland, Ohio. We operate 33 horizontal injection presses with clamping forces ranging from 38 to 500 tons. As a result, we can accommodate a wide variety of part geometries, tolerances and size requirements. APC is a custom mold builder and molder of thermoplastic injection molded parts. APC specializes in high volume production of precision parts used in automated assembly. Additionally, we specialize in molding heavy wall parts for specialty fittings that are later machined in a secondary operation. For more information on Automation Plastics visit www.automationplastics.com.
Dan Kerkhoff
Posted at 05:10h, 05 AugustLooks great JD Technologies! I suggest you publish something along these lines on some regular basis. Looks good. Regarding using plastics vs aluminum or other metals, you might also want to point out the greater design flexibility of plastic as compared to the other materials; particularly as to how it offers substantial part consolidation possibilities.
John Knott
Posted at 05:31h, 05 AugustDan, Thank you for your kind words, coming from you who has such an extensive plastics background with world class companies like Tessy Plastics is quite a compliment. We are planning on publishing more technical content like this from experts in the field. I have already spoken to our principal Automation Plastics who is on board the the value this has to our customers and their involvement with future publications.
In your comment you mentioned the greater design flexibility of plastics, very good point and an excellent topic for future publication via white papers and/or case studies (success stories).
Randolph J Sablich
Posted at 18:14h, 05 AugustI agree with Dan that JD Technologies should talk about the benefits of plastics versus other materials. But you should also discuss the benefits of the “other material” including DISPAL that can be incorporated into numerous applications within the Aerospace, Military & Defense and Medical Industries. JD Technologies has principals that offer fabrication and design support utilizing a variety of services that include additive manufacturing, machining, extrusion, micro-fabrication as well as plastic injection molding. The more the engineering community understands what works for which applications, the better off their end product designs will be. Keep up the great work JD Technologies!
Bill Tedeschi
Posted at 16:17h, 06 AugustNice set of reference material, thanks. Part tutorial, part design guide, with great pointers for more detail.
Bill Tedeschi
Distinguished Member of Technical Staff
Lockheed Martin
Sandia National Labs
Matt Knott
Posted at 15:05h, 19 AugustVery informative article, I will be sure to check back in to read future content. It would be great to read about specific use cases about companies that, for example, made the switch to plastics and describe how it has been working out from a design, performance and economic perspective. When I was product manager for company delivering voltage regulation solutions to the utility industry, we transitioned our control cabinet from stainless steel to polycarbonate where we increased our design flexibility while maintaining our NEMA 4X rating. Thanks for sharing this insight.