Material science has always relied on the synergies between two disparate materials to create a whole that is far greater than the sum of its parts. In this manner, PTFE is no different.

Polytetrafluoroethylene (PTFE), commonly known by the brand name Teflon, has revolutionized various industries with its exceptional chemical resistance, low friction properties, and high-temperature stability. Despite its remarkable attributes, engineers and material scientists are constantly seeking ways to further enhance its performance for specific applications. In addition to this, processors, eager to protect their market, have often resorted to special formulations that offer unique properties that only they would know how to replicate.

Over time, fillers of bronze, glass, and carbon became regularised within PTFE, lending well understood boosts in wear properties, creep, and dimensional stability. However, two promising fillers, Ekanol and ATSP, have emerged as potential game-changers in the world of PTFE.

Ekanol: A Breakthrough Filler

Ekanol, a proprietary carbon-based filler, has gained significant attention for its ability to enhance the mechanical properties of PTFE. The introduction of Ekanol into PTFE formulations has been shown to improve wear resistance, tensile strength, and thermal conductivity.

One of the key advantages of Ekanol is its ability to act as a reinforcing agent. By compounding Ekanol with PTFE, the resulting composite material exhibits increased tensile strength, making it suitable for applications requiring higher mechanical performance. Additionally, Ekanol-filled PTFE demonstrates enhanced wear resistance, addressing a common concern associated with pure PTFE in applications subjected to friction and abrasion.

Furthermore, the thermal conductivity of PTFE is significantly improved with the addition of Ekanol. This enhancement is crucial for applications where efficient heat dissipation is essential, such as in electrical insulators or components of high-performance machinery. The synergistic combination of PTFE's intrinsic properties and Ekanol's reinforcing characteristics opens new possibilities for the material's application in diverse industries.

Aromatic Thermosetting Polyester (ATSP): A Leap Forward in Dimensional Stability

ATSP, an aromatic thermosetting polyester, introduces a distinct set of advantages to PTFE when used as a filler. This nanostructured material has shown promise in enhancing electrical properties and dimensional stability, making it a valuable addition to PTFE composites.

One of the standout features of ATSP is its ability to impart excellent dielectric properties to PTFE. This positions ATSP-filled PTFE as an ideal candidate for applications in the electronics and telecommunications industries, where high electrical insulation is paramount. The nanostructured nature of ATSP ensures a uniform distribution within the PTFE matrix, contributing to consistent and reliable electrical performance.

Beyond electrical properties, ATSP significantly improves the dimensional stability of PTFE. This is especially crucial in applications where precise tolerances and minimal expansion or contraction over a range of temperatures are essential factors. The incorporation of ATSP mitigates the effects of thermal expansion, providing a more stable material suitable for aerospace, automotive, and other demanding environments.

Synergy Unleashed: Ekanol and ATSP in Combination

Recent research has explored the synergistic effects of combining Ekanol and ATSP as fillers in PTFE, unlocking new dimensions of material performance. This innovative approach aims to harness the individual strengths of each filler, creating a PTFE composite with a well-balanced set of properties.

The combination of Ekanol and ATSP presents a harmonious blend of mechanical strength, thermal conductivity, electrical insulation, and dimensional stability. This opens up avenues for applications where a comprehensive set of properties is essential, such as high-performance gaskets, seals, and bearings used in critical industrial machinery.

 

Conclusion

The incorporation of Ekanol and ATSP as fillers in PTFE marks a significant stride in the evolution of advanced materials. These fillers not only address specific limitations of PTFE but also open up new possibilities for tailored applications in diverse industries. The synergistic effects observed when combining Ekanol and ATSP highlight the potential for creating PTFE composites with a broad spectrum of enhanced properties. As research continues to unravel the full potential of these fillers, the future holds exciting prospects for PTFE and its role in shaping technological advancements across various sectors.

---

Read More

1. Optimizing Solar Tracker Bearings for Enhanced Solar Energy Harvesting

2. PEEK Vs Polyimide - Comparing Two of the Toughest Polymers

3. PTFE Extrusion - Ram vs Paste Extruded - A comparison of features

In the pursuit of sustainable energy sources, solar power stands out as a prominent solution for mitigating the environmental impact of traditional energy generation methods. While wind and hydroelectric energy are no doubt gaining traction, solar power remains our most abundant source of energy. Harvesting this efficiently is the key to moving into a phase where fossil fuels are no longer vital to the survival of industry. 

Solar trackers play a crucial role in maximizing the efficiency of solar panels by ensuring they follow the sun's trajectory throughout the day. This is especially needed in countries further away from the equator, where the angle of the sun changes more dramatically with seasons and where the intensity of the sunlight is weak and therefore needs to be harvested more effectively.

At the heart of these solar trackers are specialized components known as bearings, which enable smooth and precise movement, and which reduce the friction of the system, allowing for less energy consumption. This article delves into the significance of solar tracker bearings, their types, and the advancements in bearing technology that contribute to the optimization of solar energy harvesting.

The Basics of Solar Tracker Bearings:

Solar trackers are devices that orient solar panels to face the sun, maximizing the amount of sunlight they receive and, consequently, the energy they generate. Bearings are fundamental components of solar trackers, facilitating the movement of the tracking system. The primary purpose of these bearings is to enable the solar panels to follow the sun's path from sunrise to sunset, ensuring they are always positioned at an optimal angle to capture sunlight.

Ultimately, solar energy is a weak source when compared with non-renewable sources. Hence, the power that is generated by a solar plant needs to exceed the power used to run the plant if the project is expected to be viable. Building efficiencies into the system minimise the energy consumption. Low friction solar tracker bearings that allow easy movement  of the solar panels are therefore crucial.

Types of Solar Tracker Bearings:

Azimuth Bearings:

Azimuth bearings enable horizontal rotation of the solar tracker, allowing it to follow the sun's east-west movement. These bearings play a pivotal role in ensuring that solar panels are oriented correctly throughout the day.

Elevation Bearings:

Elevation bearings, on the other hand, facilitate the vertical movement of solar trackers, ensuring that panels can track the sun's movement on its daily arc. These bearings are critical for adjusting the tilt angle of the solar panels based on the sun's position in the sky.

Polar Bearings:

Polar bearings are responsible for the rotational movement of the solar tracker around the polar axis. This rotation is essential for tracking the sun's seasonal variations, accommodating changes in its elevation angle throughout the year.

Advancements in Solar Tracker Bearing Technology:

With the advancements in polymer technology, the option now exists to make bearings that withstand high loads, offer low friction with minimal lubrication, and are highly cost effective against metal bearings.

Experimenting with different formulations that optimise all elements of the solar tracker bearing’s functions yields certain elements that are essential in building an effective bearing solution. These include:

1. 3D modelling to create an efficient, low-weight lattice structure that can accommodate the required radial loads of 1.5-2 Tonnes. Lower weight also means the bearings are far more cost effective 

2. The incorporation of friction reducing additives that, if blended properly, will allow the bearings to smoothly function with no external lubrication. Early bearings manufactured from plain polymers were working will in the summer. But once winter set in, loud squeaking sounds could be heard as the tracker rotated the panels. A new friction-reducing formulation erased this issue completely

3. The addition of UV protection additives that ensure that 99.9% of ultraviolet radiation does not penetrate below 0.1mm of the bearing surface. This has allowed our bearings to undergo 100-year tests and suffer no observable polymer degradation at the end

4. The development of housing using complementary polymers that offer the lowest coefficient of friction against the bearing.

The benefits of Solar Tracker Bearings made with these factors considered are many

1. Maintenance-Free - Traditional bearings may require regular maintenance to ensure optimal performance, but advancements in bearing technology have led to the development of maintenance-free bearings. These bearings, often sealed or lubricated for life, reduce the need for frequent inspections and maintenance, contributing to the overall reliability of solar tracker systems.

2. High Precision and Accuracy - Precision and accuracy are crucial factors in solar tracking systems. Modern bearings are designed with enhanced precision, minimizing tracking errors and ensuring that solar panels consistently align with the sun. This increased accuracy results in higher energy yields from solar installations.

3. Durability in Harsh Environments - Solar trackers are deployed in outdoor environments where they are exposed to varying weather conditions. Advanced bearing formulations are engineered to withstand harsh environmental factors such as extreme temperatures, humidity, UV, and other corrosive elements, ensuring long-term durability and performance.

4. Low Friction – Solar Tracker Bearings are designed to minimize energy losses during the rotation of the solar trackers. By reducing friction, these bearings enhance the overall efficiency of the tracking system, allowing solar panels to smoothly follow the sun's movement with minimal energy consumption.

5. Dual-Axis Tracking Systems - While single-axis tracking systems follow either the horizontal or vertical movement of the sun, dual-axis tracking systems incorporate both azimuth and elevation tracking. Bearings in dual-axis systems are specially designed to facilitate complex movements, ensuring precise alignment with the sun at all times. This results in even greater energy capture efficiency, especially in locations with high solar irradiance.

Conclusion:

The capability to design the bearings, create a precise formulation of the polymer based on the environment of use, and mould or even machine the bearings and housings as needed is what sets apart companies looking to engineer bearings rather than simply mould them from a template. This all-round capability allows us to treat each project as unique and develop a solution that effectively targets the customer’s needs and boosts the overall efficiency of the project.

It is likely that as the industry matures, the bearing technology too will evolve. Nonetheless, we expect to be at the forefront of this product that is at the heart of the green energy revolution.

---

Read More

1. PEEK Vs Polyimide - Comparing Two of the Toughest Polymers

2. PTFE Extrusion - Ram vs Paste Extruded - A comparison of features

3. Exploring the Versatile World of PVDF

In the realm of high-performance polymers, PEEK (Polyether Ether Ketone) and Polyimide stand out as two exceptional materials. Both are undoubtably among the toughest polymers, exhibiting tensile and flexural strengths far higher than even their nearest competitors. Given this, it is easy to see them as substitutes for one another and for an engineer to be confused over which one to choose in a given application. 

Comparing chemical structure:

PEEK is a semi-crystalline thermoplastic known for its excellent mechanical properties, chemical resistance, and high-temperature stability. Its molecular structure imparts exceptional resistance to chemicals, abrasion, and wear. 

On the other hand, Polyimide (often known by its brand names of Vespel or Kapton) is a high-performance polymer with a unique imide linkage in its molecular structure. This arrangement contributes to outstanding thermal stability, excellent dielectric properties, and exceptional resistance to radiation and chemicals. 

Mechanical Properties:

When it comes to mechanical properties, PEEK and polyimide both display distinct characteristics. PEEK offers a combination of high strength, stiffness, and toughness. Its tensile strength and modulus are comparable to some metals, making it a preferred choice in structural applications where mechanical integrity is crucial. PEEK's inherent toughness allows it to withstand repeated loading and impact without sacrificing performance. PEEK can also be enhanced with the addition of Glass, Carbon, and Graphite (Carbon-Graphite reinforced PEEK, also called HPV PEEK, is among the toughest polymer compounds known), which adds to PEEK’s versatility.

Polyimide, while not as stiff as PEEK, excels in maintaining its mechanical properties at elevated temperatures. Its ability to withstand prolonged exposure to high temperatures without significant degradation makes polyimide suitable for aerospace, electronics, and automotive applications where a combination of thermal stability at elevated loads is paramount.

When it comes to wear resistance, polyimide take the edge, as it exhibits a slightly lower coefficient of friction. While PEEK can be improved with the addition of PTFE, the base wear rate of polyimide is both low and constant over a range of loads. This means that in dry-running applications it is a better choice.

Thermal Stability:

Thermal stability is a key consideration in many high-performance applications, and both PEEK and polyimide offer exceptional heat resistance. PEEK is known for its thermal stability up to 260°C, making it suitable for applications in aerospace, automotive, and oil and gas industries. However, polyimide surpasses PEEK in terms of thermal stability, with some formulations capable of withstanding temperatures exceeding 300°C. This makes Polyimide the material of choice in extreme temperature environments such as electronics and aerospace applications.

PEEK boasts a high glass transition temperature (Tg) of around 143°C, making it suitable for applications in demanding thermal environments. However, polyimides typically exhibit a higher glass transition temperature than PEEK, often exceeding 250°C, making them more ideal for applications demanding extreme temperature resistance.

Chemical Resistance:

Chemical resistance is another critical factor in material selection, especially in harsh operating conditions. PEEK exhibits excellent resistance to a wide range of chemicals, including acids, bases, and hydrocarbons. It is also biocompatible. This makes it a preferred choice in chemical processing, medical, and oil and gas applications. Polyimide, with its unique molecular structure, provides outstanding chemical resistance, particularly against solvents, acids, and radiation. This property makes Polyimide suitable for applications in the aerospace, electronics, and semiconductor industries.

Cost and processing considerations

When it comes to cost, however, there is little need to compare the two. Polyimide’s key drawback is that it is prohibitively expensive. Polyimide is roughly 3-4X the cost of PEEK, which is significant considering that PEEK itself is about 20-25X the cost of more basic polymers such as POM or Nylons. Hence, most parts made from polyimides tend to be smaller and used sparingly in applications where PEEK does not make the cut.

Processing-wise, the other drawback of polyimide is that it cannot be injection moulded. It can only be compression moulded or extruded as a rod. This limits the complexity of parts that can be made when compared with PEEK. However, when we speak of compression moulding specifically, polyimide is more versatile and comparatively easier to process. While PEEK only lends itself to hot compression moulding (where the pressure and temperatures must act simultaneously), polyimide can also be cold compression moulded in a manner similar to PTFE. This allows for a much higher productivity, wherein material can be compressed and placed in an oven in batches, rather than moulded one at a time the way PEEK needs to be.

Conclusion

While it is fair to compare PEEK and Polyimide, the key consideration of cost means that PEEK usually wins out. However, there are certain applications where only Polyimide can be used and where cost may not be the biggest concern. It is likely that as polyimide gets cheaper (as polymers invariably do over time), the use cases will rise, and PEEK will have a worthy competitor.

---

Read More

1. PTFE Extrusion - Ram vs Paste Extruded - A comparison of features

2. Exploring the Versatile World of PVDF

3. Air Permeability Testing and Water Entry Pressure Testing in Expanded PTFE Membranes