Machining plastics is as much a skill as it is an art form. It takes understanding that whenever you cut a part, it will probably have some motion or energy still within the material.
This is largely because a lot of parts have more rebound than steel in the cutting process. And while plastics are mostly thermally stable, they’re not dimensionally, thermally stable.
Changes in temperature from the time the part is machined, inventoried, and put into service show that typically parts are constantly changing in size. PTFE or Teflon suffer the greatest change in thermal instability where we machine the part, around 74 degrees Fahrenheit.
You might think that if you can make a part and verify that it’s intolerance, then the part is process-capable. But the reality is that a large tolerance range doesn’t make a part process-capable.
With the marijuana and cannabis industry expected to take in nearly $24 billion by the end of in 2021, and more than $40 billion by 2025, the market is primed for innovation in production volume and technology.
The growth in popularity of vaporizers, infused edibles, and topical cannabis products means the demand for cannabis oil extraction is a fast multiplying industry.
The two primary means for oil extraction is via petroleum based solvents such as butane or propane, or by supercritical fluid extraction (most often carbon dioxide, or CO2).
Supercritical fluid extraction has been around for decades, and has been used in a wide variety of industries, including decaffeinating coffee and extracting essential oils. But the explosive growth and demand of the cannabis industry has raised the need for increased volume and reduced cycle time to new heights.
Our partners at Eclipse have been approached by multiple
Controlling friction using the properties of Teflon® and adjusting the durometer of an energizing elastomer allows us to adjust the load and control the force the seal applies.
Seals are often used as a barrier or exclusion device. When considering a device that becomes sterilized, seals often protect the internal components of that device.
Some systems require adjustment of the mechanism. Friction becomes a factor when making internal adjustments. An O-ring is always the easiest solution for sealing. But for fine adjustments, reducing the friction allows more control of the device.
The machining of polymers such as PTFE, still remains somewhat of a specialty operation. While there are a plethora of machine shops dotted across the country focused on metal turning and milling operations, few specialize in plastics.
Only someone experienced in metalworking might call machining something like PTFE easy. PTFE is much softer and easier to cut than something like steel or aluminum.
While this certainly is true, polymers present their own unique set of manufacturing challenges, especially when tight-tolerance parts are required. And with Eclipse’s business of aerospace and specialty applications, they almost always are.
As the operating parameters of industrial technologies and manufacturing processes get more extreme, the need for optimal sealing solutions become that much more important.
Elevated temperatures and pressures, higher speeds, extreme environments, faster gas decompression, and aggressive medias all make sealing more critical. This extends right across static, reciprocating, rotary, and oscillating applications.
This challenge has been met very effectively by the inventive addition of energizers to seals. Energized seals give the ultimate performance in the most demanding conditions and critical applications.
Spring or o-ring energizers can extend the normal limits of PTFE and plastic materials to deliver durable ultra-tight sealing capability. Here’s a rundown of how energizers work and how they can elevate your next sealing challenge.
The Industrial seal market is by far the broadest and most encompassing of all seal markets. This industry uses seals that need to function with every fluid imaginable, temperature ranges from absolute zero to over 1000 °F, and pressures exceeding 100k PSI.
Industrial seals also include rotary seals that can see a vacuum to PV’s (pressure-velocity) that can often exceed 500K-PV.
Solving our industrial seal customers’ problems requires our seal designer to understand how the equipment will operate.
The Backup ring likely found its roots in the use of leather packings, where leather was used as the sealing device in glands prior to the use of O-Rings.
The O-ring provided a much better seal compared to leather. However, the leather often filled the extrusion gap allowing for larger gaps.
The persistent problem that engineers faced was how to take an O-ring that operated optimally in close extrusion gaps, and extend its service with widening extrusion gaps.
The answer was the Backup ring.
Here we’ll discuss the basic functionality and design principles of spring energized seals and discover why one might be the perfect sealing solution in your application. This article was written by GFS supplier/partner Eclipse Engineering.
Spring energized PTFE seals perform reliably in a variety of applications where conventional elastomeric seals fail due to chemical attack, extreme heat or cold, friction, extrusion or compression set.
Difficult seal applications come from all industries and sectors of the economy.
While far-reaching operating conditions certainly consume their fair share of engineering hours, often one constraint also probes the boundaries of sealing technology and design ingenuity: limited hardware space.
A manufacturer was using a pneumatically actuated cylinder to dispense a chemical in a production process. The piston was drawn back in the cylinder thus filling it with the chemical product. The piston was then pushed forward to dispense the chemical out of a nozzle.
Polytetrafluoroethylene (PTFE) resin is a highly effective material for seal consumers due to its extremely low friction, high heat tolerance and chemical inertness.
With the right additives, PTFE resin can perform even better in terms of strength, thermal performance, chemical resistance and abrasion.
However, there are a few design considerations when using PTFE resin, particularly when combined with glass fiber and bronze.
This blog will examine PTFE fillers to enhance PTFE performance.