The Elastic World of Rubber

With the lines becoming increasingly blurry between the use of thermo-set elastomers and thermo-plastic elastomers in today's marketplace, what distinguishes rubber from plastic in the context of micro-precision parts? With smaller parts and more demanding applications with difficult configurations becoming the norm, what are the unique challenges this presents for part design and material specification? Thermoset elastomers or rubber is often misunderstood and looked at as interchangeable with plastic. This is not the case, as the chemical properties and molding characteristics of rubber are unique.

Rubber vs. Plastic

* Rubber is a better material for dynamic sealing
applications
x Plastic is a lower cost material for high volume
production
* Rubber has a wider hardness range, and can be
very soft or very hard
x Plastic is a better material for many retail or
commercial applications
* Rubber is an excellent solution for a range of
different temperatures
x Plastic does not perform well in extreme heat or
cold
* Rubber works well with bonding agents for bonding
rubber to metal or plastic substrates
x Plastic is a better option when you need a very
hard or rigid material
* Rubber is a better option when you need a
flexible material
* Rubber is a high performance material when
acoustic or vibration absorbing properties are
important

Rubber is a complex and often misunderstood material that traces its history all the way back to the Ancient Civilizations of Central Mexico around 1600 BC. Mayans and Olmecs drained latex rubber sap from local trees and mixed it with juice from the morning glory vine to create a durable, elastic material. They used this latex rubber material for everything from rubber balls for ceremonial games to bindings for tools.

Cardiac Pacemaker Further rubber evolution came in the form of vulcanization, the process of mixing natural rubber with other ingredients and adding heat. This process, commonly accredited to Charles Goodyear in 1839, created a more dependable, elastic material. Today more than seventy five percent of the rubber being used is synthetic, and originates from a barrel of oil. Rubber is a thermoset elastomer distinct and different from its plastic counterpart (TPE).

Today, modern synthetic rubber materials are designed specifically for the end use or application. Materials like Silicone, EPDM, Nitrile, and Fluorocarbon bear little resemblance in either chemistry or performance to its natural rubber ancestor. Rubber is being used to save lives in pacemakers and defibrillators, help power construction equipment in dynamic seals and pumps, and perform vital functions in many of the commercial products we use every day.

How can rubber work for you?

Rubber vs. Plastic Design Considerations
There are several fundamental differences involved in rubber vs. plastic design. The flexibility of rubber itself offers greater design freedom than does its plastic counterpart. Draft does not need to be designed into rubber parts, undercuts and tubes with bends can be accommodated, and rubber parts can be manually removed from molds.

Design Optimization
While designing rubber parts certainly adds a degree of flexibility, it is always beneficial to consult with the team at Flexan when designing new elastomeric components. We can help optimize the impact of your designs and increase your speed to market. Our engineers and chemists can offer guidance and assistance with tool design and material selection. We can customize our process to take into account; functional requirements, tight tolerances, part assembly, and cost parameters. We can sample and prototype parts, help design prototype tools, and facilitate a speedy R&D process.

Experience and Expertise
Our engineering staff has decades of experience working with customers and assisting in the product development process. We provide the most value when we are consulted early in the design process, when Flexan can be your rubber expert.