3D Printing
by Jackie Johnson Jackie Johnson No Comments

History of 3D Printing

3D Printing, or additive manufacturing, is older than most people think. In fact, it has been around since the 1980s! Today we will go over this technology’s exciting history, from its earliest prototypes to today’s use. In this blog post, we will go over the history of 3D printing, from it’s earliest prototype to today!

While the concept of 3D printing has been around since the 70s, the first experiments began in 1981, when Dr. Kodama began research into a rapid prototyping technique. He was the first person to describe the layer-by-layer development that 3D Printing is famous for. Dr. Kodama used SLA (Stereolithography), which is a photosensitive resin that he then polymerized with a UV light. While it is clear that Dr. Kodama was the first to describe, he, unfortunately, did not file the patent in time.

In 1986, an engineer by the name of Charles Hull submitted the first patent for SLA. Two years later he founded the 3D Systems Corporation and released the SLA-1, the first, official, 3D printer.

1988 was a big year for 3D printing technology! That year, along with the founding of 3D Systems Corp, the University of Texas was also dabbling in the fledgling technology. Carl Deckard developed a patent for selective laser sintering (SLS) which is a 3D printing technique in which powder grains are fused together by a laser. At the same time, Stratasys Inc. filed a patent for fused deposition modeling (or FDM).

The 90s had its share of 3D printing innovations. But it wasn’t until the 2000s when 3D printing as we know it really gained traction, especially in the media. 2000 saw the world’s first 3D printed kidney, which put the spotlight on the technology. In 2004, home printers started to become more readily accessible, leading to a boom in the maker community that is still going strong today.

2008 saw the world’s first 3D printed prosthetic limb, 2010 the first 3D printed car. There seemed to be no limit to what this technology could do. And in 2013, then-President Barak Obama included it as a major issue in his State of the Union speech.

3D Printing is continuing to grow and expand, with sights focused on the ability to print in more materials. Today printers can use industrial-strength materials such as PEEK, PTFE, nylon, and even metals. There are also several types of research being done on the subject of 3D Bioprinting, which could completely change the medical industry. There truly is no limit to what this technology can do. We are just beginning to scratch the surface of what 3D printing can do.

Missouri Spring Energized Seal Company
by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

Types of Springs Used in Energized Seals

Spring-energized seals are able to provide reliable, consistent sealing where other seals fail. The key to their performance lies in the additional sealing force made possible through a spring, but not all springs provide the same type of performance. In this blog post, we are going to talk about the four most common types of spring energizes: canted coil springs, cantilever springs, V springs, and helical springs.

Canted Coil Spring

Canted coil springs are wound at an angle to the axis along the length of the spring. They are able to maintain a very consistent force of over a wide deflection range, which contributes their popularity as a seal energizer. The load is primarily applied at the tip, which is excellent for sealing unless abrasive media is involved.In addition, these springs can be tailored to achieve specific forces. They are ideal for applications where friction needs to be minimized, including flap actuators and encoder and are often found in applications that involve dynamic rotary or reciprocating motion. Canted coil spring energizers work best for moderate to high speed rotary applications.

Cantilever Springs

Cantilever springs, also known as finger springs, have a v-shaped cross-section.These springs have a linear load curve (deflection and force as linearly related). Because of their shape, the load is concentrated at the very front of the seal which makes them a good choice for exclusion  and scraping applications. Spring-energized seals with cantilever springs work well for low to medium speed applications and can be found on hydraulic cylinders, pumps, shocks, and compressors.

V Springs

The V spring, also called a V ribbon spring, is a general purpose energizing spring that provides good performance at a relatively low cost.  which offers good performance at a relatively low cost.  V spring energized seals are well adapted to severe applications, including vacuum pressures and cryogenic temperatures. These seals work well for applications that involve either rotary or reciprocating motion, but also perform well in static applications. In short, V spring energizers are ideal for general purpose applications.

Helical Spring

The helical springs, sometimes referred to as a helical wound spring, consists of a wound ribbon of metal that results in a relatively high load versus displacement curve, which also means their deflection range is quite small. Because of this, it can provide very tight, reliable sealing even in the presence of extreme pressures (including vacuum). Helical spring energized seals also work well for sealing in lightweight gases or liquids. However, they should be limited to either low speed, intermittently dynamic, or static applications where achieving a reliable seal is significantly more important than the effect of friction or the possibility of wear. Helical spring energizers are often used on pipe flanges and crush jackets where the seal jacket needs to be embedded into any surface irregularities.

Full Contact Spring

A Full Contact Spring provides a high-load, continuous spring contact along the entire circumference of the sealing lip. A full contact spring is recommended for extreme sealing conditions, such as those involving cryogenics, vacuum and/or light gases at low pressure. Because of its extreme chemical resistance and temperature applications, it is recommended for high-altitude aerospace and even space exploration missions. 

Conclusion

If you are looking for a sealing solution involving an application where other seals have failed, spring-energized seals are an excellent option. Not only do you have flexibility in the choice of sealing jacket, you can also find spring energizers adapted to the particular challenges you are facing.