Today's KNOWLEDGE Share : Insights into carbon fiber production (Part 2/5)

Today's KNOWLEDGE Share

Insights into carbon fiber production (Part 2/5)

Carbonization - a model of efficiency and precision

After the oxidation stage, the fibers enter the carbonization stage, where they are processed in special high-temperature furnaces at over 1500°C. The oxidized fibers are refined in a controlled, inert atmosphere - usually nitrogen or argon. These conditions are critical to avoid combustion and prevent unwanted chemical bonding with external elements.

During this phase, the fibers undergo crucial chemical transformations that adapt their microstructure and optimize them for demanding mechanical applications. The yarns are also fed through the furnace in a dense configuration, which not only reduces the footprint but also enables significant energy savings.

Carbonization is thus a prime example of the efficiency and precision with which Teijin refines its products to deliver industry-leading carbon fibers used in aerospace, automotive and many other sectors.

source:Teijin Carbon America,Inc

#carbonization #carbonfiber #carbonfiberproduction

Today's KNOWLEDGE Share : Filling at constant pressure

Today's KNOWLEDGE Share

Historically, early injection molding machines would essentially be pressure controlled.

Many good parts have been made under such process control. So, it is not all bad !

However, note that when molding an end-gated fairly long part, a constant pressure fill translates into an ever decreasing melt front velocity, as the pressure drop builds up.

This in turns corresponds to a decreasing average temperature of the melt front along the flow.

Such a decreasing T will create an increasingly strong degree of molecular orientation when moving away from the gate. The part, especially when using semi-crystalline grades, will have a strong gradient of mechanical properties along the flow which could be as serious as showing good ductility near the gate and severe brittleness far from the gate.

source:Vito leo

#injectionmolding #polymers

Today's KNOWLEDGE Share : PEKK, and PEEK

Today's KNOWLEDGE Share

Understanding the Differences Between PEKK, and PEEK Materials:

PEKK and PEEK are both in the Polyaryletherketone family of ultra-high performance polymers. 

Unlike PEEK, PEKK is a copolymer with a slower and highly tunable crystallization rate making it the preferred choice for additive manufacturing.

PEKK can be printed directly in either the amorphous or semi-crystalline state, or printed amorphous and crystalline in a secondary process, offering the ultimate combination in performance and processing flexibility.

   

CHEMICAL COMPOSITION AND STRUCTURE

PEKK (Polyetherketoneketone):

Structure: PEKK consists of ether (O) and ketone (C=O) linkages,with two ketone groups in the repeating unit. This structure provides high thermal stability and chemical resistance, making PEKK ideal for demanding environments.

PEAK (Polyetherketone):

Often confused with PEKK, PEAK is a general term referring to various types of polyetherketones. It includes polymers with similar structures but slight variations in the arrangement of ether and ketone groups, encompassing both PEKK and PEEK among others.

THERMAL PROPERTIES

PEKK boasts a higher glass transition temperature (Tg) and melting point compared to PEEK.

Tg typically ranges between 160°C to 165°C.

Melting point is around 340°C.

PEEK:

Tg is around 143°C.

Melting point is approximately 343°C.

MECHANICAL PROPERTIES

PEKK: The additional ketone group in PEKK increases rigidity, resulting in higher mechanical strength and stiffness.

It offers better wear resistance and a lower coefficient of friction, which is advantageous for high-stress applications.

PEEK provides an excellent balance of toughness, stiffness, and strength.

It is slightly more flexible than PEKK, which can be beneficial for applications requiring a degree of ductility.

CHEMICAL RESISTANCE

PEKK:

The more rigid structure of PEKK grants it superior chemical resistance.

It excels in resisting a wide range of chemicals, including acids, bases, and organic solvents.

PEEK is highly resistant to many chemicals, though slightly less so compared to PEKK.

Its chemical resistance is still exceptional,making it a reliable choice for harsh environments.

PROCESSING AND APPLICATIONS

PEKK can be processed using similar methods as PEEK,such as injection molding, extrusion, and 3D printing.

It is commonly used in aerospace, automotive, and medical applications where high performance is required under extreme conditions.

PEEK is widely used across various industries, including aerospace, automotive, electrical, and medical devices.It is easier to process than PEKK due to its slightly lower melting point and greater flexibility.

Additive Manufacturing and Injection Molding:

Both PEKK and PEEK have significant implications for additive manufacturing (3D printing) and injection molding.Their high-performance properties allow for the production of complex, precision parts that can withstand extreme conditions.

source:addmangroup/arkema

Today's KNOWLEDGE Share : catalysts will power China's first biomass-to-green methanol project

Today's KNOWLEDGE Share

Clariant's MegaMax™ catalysts will power China's first biomass-to-green methanol project

Clariant, a sustainability-focused specialty chemical company, announced today that its MegaMax catalyst was selected for a China’s biomass gasification-to-green methanol project. The plant will use a combination of farm waste and wind power to produce up to 250,000 tons per annum of green methanol in two phases by 2027. Construction of the first plant phase began in March 2024 and is expected to start producing green methanol in the first half of 2025 as China’s first commercialized biomass gasification-to-green methanol plant.

Georg Anfang, Vice President Syngas and Fuels at Clariant Catalysts, commented, “We are very pleased to be part of this groundbreaking project. With over 50 years of expertise in methanol synthesis and a clear commitment to developing innovative catalysts for the energy transition, we are an ideal partner for this prestigious sustainability project. Green methanol will play a crucial role as renewable fuel as well as feedstock for green chemical production.”

Clariant’s MegaMax is an excellent solution for China’s first biomass-to-methanol project, as it provides enhanced stability and tolerance to the fluctuation of the system required for green methanol production. It also offers outstanding activity – even at very low reactor temperatures and pressures. Thanks to the catalyst’s enhanced selectivity, production yield is low in by-product formation, significantly improving the economics of green methanol synthesis.

Clariant will provide comprehensive technical service to ensure optimal catalyst performance through its Applied Catalyst Technology (ACT) team of highly qualified engineers and experts. Further support can be provided through the CLARITY™ digital service portal, which offers access to real-time plant data to enhance reliability, safety, and profitability.

source:Clariant

Today's KNOWLEDGE Share : 3 unusual traits of the hemp plant that you might not be aware of

Today's KNOWLEDGE Share

The Hemp plant has thousands of ways to be used. Here's 3 unusual traits of the hemp plant that you might not be aware of:

1.Phytoremediation Properties: Hemp has the remarkable ability to clean and restore soil health. It can absorb heavy metals, toxins, and even radiation from the soil through a process known as phytoremediation. This makes it useful for cleaning up contaminated land.

2.Versatile Biomass Potential: The entire hemp plant can be utilized, making it one of the most efficient crops. Its stalks can be used for fibre and hurd (building materials and animal bedding), seeds for food and oil, and leaves and flowers for medicinal and recreational products. This versatility reduces waste and maximizes the plant’s economic value.

3.High Resistance to Pests and Diseases: Hemp is naturally resistant to many pests and diseases, reducing the need for pesticides. This resilience not only makes it a more environmentally friendly crop but also lowers production costs for farmers. As I said, thousands of uses - but these 3 traits/uses alone are fantastic! Try Hemp Today.

#hemp

source:Biocomposites Group

Today's KNOWLEDGE Share : Highlights marine biodegradability of Eastman Aventa™ compostable materials

Today's KNOWLEDGE Share

New research highlights marine biodegradability of Eastman Aventa™ compostable materials

A groundbreaking new study published in ACS Sustainable Chemistry & Engineering reveals that cellulose diacetate (CDA)-based foams made with Eastman Aventa™ compostable materials rapidly biodegrade in the marine environment. The article concludes that biodegradable, CDA-based foams are commercially useful and will not persist in our oceans as plastic pollution. 

Scientists from Woods Hole Oceanographic Institution (WHOI), the world’s leading independent, nonprofit organization dedicated to ocean research, exploration and education, led the study. WHOI’s research and journal article focuses on CDA-based foams made with Aventa, which lost up to 70% of their mass after 36 weeks of incubation in seawater. In contrast, polystyrene foams a material commonly used for food packaging showed no signs of degradation. The study found that CDA foams degrade faster than any material evaluated under environmentally relevant marine conditions more than quadruple that of paper and up to 1,000 times greater than solid polypropylene, polystyrene and polylactic acid (PLA).  

“Foaming biodegradable bioplastics like Aventa offer a promising strategy to reduce the environmental impact of frequently mismanaged consumer plastics, particularly in food packaging applications,” said Collin Ward, associate scientist at WHOI and lead researcher for the study. “These materials not only degrade rapidly in the ocean but also support circularity and material efficiency.”  

The study dives deeper into a systems-level assessment for redesigning plastic articles for food packaging applications, considering material performance, economics, sustainability and circularity. Aventa is a cellulosic material derived from sustainable wood pulp, ensuring a renewable and sustainable beginning of life, and its compostability translates into a sustainable end of life. 

Polystyrene is commonly used in food packaging, but it is not biodegradable and is difficult to recycle. The study concludes, through calculations that include annual consumption rates and the social costs of pollution, that switching from polystyrene to CDA-based foams for food trays could potentially save society more than $1 billion by reducing costs associated with plastic pollution. The study highlights the need for holistic assessments of environmental impact to avoid swapping one issue for another.  

“Traditional plastic foams face challenges in end-of-life management, often unintentionally ending up as plastic pollution in the environment,” said Jeff Carbeck, vice president of Eastman corporate innovation and care solutions technology. “Eastman Aventa materials offer a sustainable alternative, and this research shows that CDA-based foams will not contribute to persistent marine plastic pollution.” 

source:Eastman

Clariant launches melamine-free flame retardant for intumescent coatings:

Clariant has launched its new generation of melamine-free flame retardants, a safer, more future-proof solution that delivers superior fire performance and meets the stringent requirements of modern industry.

The classification of melamine as a substance of very high concern (SVHC) in 2023 makes Exolit AP 422 A a valuable asset for the fire protection industry, enabling coatings and sealant products to maintain high performance standards without relying on melamine.

 

In response to current and future regulatory challenges surrounding melamine, Clariant has been actively working on this innovative solution for several years, developing a SVHC-free alternative to the existing melamine-containing Exolit AP 422 flame retardant.

 

“Exolit AP 422 A builds on the proven reliability of Exolit products in the market and ensures that our customers’ fire protection products remain competitive, especially in terms of chemical compliance. It enables manufacturers to adapt to changing regulations while maintaining the effectiveness of their fire safety solutions.

 

The new Exolit AP 422 A addresses concerns surrounding melamine as a substance of very high concern while providing superior fire protection performance in a variety of applications such as intumescent coatings, fireproofing sealing systems and PIR insulation boards. Its non-halogenated nature helps to minimize harmful emissions, providing safer use in critical industries.

 

Christian Battenberg, Global Business Development Manager for Polymer Solutions at Clariant, added: “Exolit AP 422 A responds to key market trends around increasingly stringent fire safety standards, environmental and health concerns, regulatory compliance needs, operational efficiency demands and the need for versatile solutions across multiple applications.”

 

Customers who have already incorporated Exolit AP 422 A into their fire protection products describe the new melamine-free flame retardant as a game-changer as it delivers reliable fire protection while also meeting sustainability commitments.

source:Clariant/www.echemi.com