Today's KNOWLEDGE Share : World’s First Ultra-Thin Polyimide Film

Today's KNOWLEDGE Share

The World’s First Ultra-Thin Polyimide Film at Just 4 Micrometers (μm)!

The world's thinnest ultra-film :

By producing this 4-micrometer ultra-thin polyimide film, following the successful commercialization of a 5-micrometer ultra-thin film, PI Advanced Materials has demonstrated its unrivalled film-making technology on a global scale. The development is expected to provide a competitive edge to the company in the market for lightweight products, essential to the growing trend of slimmer electronic devices, including smartphones.

Essential material in the electronics 

Polyimide films are essential materials in the electronics, aerospace, and automotive industries due to their exceptional heat resistance and strength. While most polyimide films are produced in thicknesses ranging from 12.5 to 25 micrometers, PI Advanced Materials stands out as the only manufacturer worldwide offering a 4-micrometer polyimide film produced by a non-stretching process.

Lightweight and compact devices

These ultra-thin polyimide films are essential for developing lightweight, compact electronic devices such as smartphones, high-performance displays, and wearable technology. They are expected to provide innovative solutions across various applications, including battery materials. Notably, the 4-micrometer film, which is approximately 1/25th the thickness of a human hair, is both lightweight and flexible, making it ideal for miniaturizing components for flexible display panels. These ultra-thin polyimide films can dramatically reduce the thickness and weight of high-definition display panels while enhancing electric vehicle battery efficiency through weight reduction. Starting next year, it will also be applied to improve the heat resistance and durability of smartphones, tablets, and wearable devices.

source:Arkema

Researchers explore sunlight-based recycling for black plastic waste:

A new method for recycling black polystyrene plastics, such as coffee lids and food containers, could help divert these materials from landfills. The approach, reported in ACS Central Science, uses sunlight or white LED light to transform black and colored polystyrene waste into reusable chemical components.

Black plastics are notoriously difficult to recycle due to the color additives complicating sorting processes. Researchers at Cornell University and Princeton University, led by Sewon Oh, Hanning Jiang, and Erin Stache, have developed a technique that uses carbon black, a common additive in these plastics, to initiate a recycling process using light. “Simple, visible light irradiation holds the potential to transform the chemical recycling of plastics, using the additives already found in many commercial products,” the authors stated.

The method involves grinding polystyrene mixed with carbon black into a fine powder, which is then sealed in a glass vial. Exposing the vial to high-intensity white LED light for 30 minutes causes the carbon black to absorb the light and convert it into heat. The heat breaks the polystyrene’s molecular structure, yielding smaller chemical components — mainly one-, two-, and three-styrene units. These byproducts were effectively separated during the process, and both the carbon black and styrene monomer were recycled to create new polystyrene, demonstrating the potential for a circular recycling system.

When applied to post-consumer black plastic items such as coffee lids and food containers, the method converted polystyrene into styrene monomer at a rate of up to 53%. The process was slightly less efficient for plastics contaminated with substances like soy sauce or canola oil. However, switching from LED light to focused sunlight significantly improved efficiency, achieving conversion rates as high as 80%.

The technique was also tested on a multicolored mixture of polystyrene waste, including black, yellow, red, and colorless materials. Under sunlight, the conversion rate reached 67%, compared to 45% under LED light. The researchers attribute the improved results to the higher light intensity sunlight provides.

The study highlights the potential for a closed-loop recycling process for polystyrene waste, mainly using natural sunlight as a more sustainable energy source. By focusing on a commonly used additive like carbon black, the researchers aim to reduce the need for additional chemicals in recycling.

Cornell University, Princeton University, and the U.S. Department of Energy’s Catalysis Science Early Career program funded the research.

source:www.rdworldonline.com

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