Today's KNOWLEDGE Share :Warpage of Glass fiber filled Nylon

Today's KNOWLEDGE Share

Warpage of a GF filled nylon part is extremely dependent on temperature and moisture uptake.

Temperature increase is responsible for matrix expansion (negligible for the fibers though), and moisture uptake produces matrix swell (again GF does not care much).

So if a part is warped when dry as molded at room temperature (that is what simulation codes will predict for you !!) it will tend to "UNWARP" as you heat the part or let it uptake moisture.

This effect can perfectly be simulated, if you account properly for the anisotropic elastic properties and fiber orientation and know the swell rate with water uptake.

For temperature induced UNWARP you will need detailed CTE (T) in x, y and z though to get it right ! Those CTE's, with the needed level of detail, are not available directly from Flow Analysis codes for the moment, but e-Xstream engineering, part of Hexagon’s Manufacturing Intelligence division Digimat software can provide those.

source:Vito leo

Today's KNOWLEDGE Share : Mercedes claims new 'solar paint' could eliminate daily EV charging:

Today's KNOWLEDGE Share

Mercedes claims new 'solar paint' could eliminate daily EV charging:

Mercedes-Benz has unveiled a list of research programs and future technologies it's working on including a "new kind of solar paint" it says could generate enough energy for up to 20,000 km (12,427 miles) of driving per year under ideal conditions.

But what if the entire painted surface of the car could capture solar energy?

Solar paint is not a new idea in and of itself; there are a few different techniques, mainly within the research space, that allow photovoltaic material to be sprayed directly onto surfaces. Painting entire cars with it, however, would be quite a leap forward – and that's what Mercedes-Benz is talking about as part of a new "Pioneering innovations for the car of the future" presentation outlining some key research programs it's working on.

Here are the key claims distilled from the Benz press release:

The solar paint would add just 5 micrometers (0.0002 in) of thickness and 50 g of weight per square meter (0.17 oz per square foot) to a standard paint job

It would operate at around 20% efficiency

An area of 11 sq m (118 sq ft), or roughly the painted surface of a mid-size SUV, "could produce enough energy for up to 12,000 km (7,456 miles) a year under ideal conditions" in Stuttgart, Germany

That annual figure would be closer to 20,000 km (12,427 miles) in LA, or 14,000 km (8,700 miles) in Beijing

It contains no rare earths, no silicon, no toxic or supply-limited materials

It's recyclable

It's "considerably cheaper to produce than conventional solar modules"

The company says that based on local solar intensity and its own data on daily driving habits, this solar paint could completely eliminate plug-in charging for the average EV owner in Los Angeles making their daily commute.

In the company's cloudier home of Stuttgart, where Benz drivers cover an average of 52 km (32 miles) daily, the paint would allegedly generate more like 62% of the required energy.

Mercedes-Benz doesn't outline exactly what the active ingredient is here, but we can take a guess. Based on the efficiency level, the thickness, the lack of rare earths and silicon, and the claimed low cost of the solar paint, we'd imagine it's probably a sprayable perovskite solution.

Perovskite has delivered higher efficiencies in the lab, and fits the rest of the profile. The chief issue over the last decade or so has been getting it to last long enough to be worthwhile, since it's proven vulnerable to water and ultraviolet light, ironically enough.

But there appear to be coatings that can make it much more robust – like the BondLynx adhesive from Canadian company XlynX, and another coating developed at Princeton University, which promises a lifespan of up to 30 years. We're yet to see anything of the sort make it through to a commercial operation, even at small scale.

Source :Mercedes Benz/www.newatlas.com

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