Today's KNOWLEDGE share:BAMBOO FIBER:

Today's KNOWLEDGE share:

BAMBOO FIBER:

Bamboo fiber yarn is a type of cellulose fiber extracted from the natural growth of bamboo and is the fifth natural fiber after cotton, hemp, wool, and silk. Bamboo fiber yarn has good breathability, instant water absorption, strong wear resistance, and good dyeing properties. It also has natural antibacterial, bacteriostatic, mite removal, odor resistance, and UV resistance functions. Bamboo fiber yarn textile products are highly favored by consumers due to their inherent properties, and the demand for these products continues to increase each year.

THE COMPOSITION OF BAMBOO FIBER

The chemical composition of bamboo fiber, also known as bamboo viscose, mainly consists of cellulose, hemicellulose, and lignin, all of which are polysaccharides and account for over 90% of the dry weight of the fiber. The other components include proteins, fats, pectin, tannins, pigments, and ash, most of which are located in the cell lumen or specialized organelles.

The cellulose content of bamboo varies depending on the age of the bamboo. For example, young bamboo may have a cellulose content of 75%, while one-year-old bamboo may have a content of 66%, and three-year-old bamboo may have a content of 58%.

THE CLASSIFICATION OF BAMBOO FIBER

Natural Bamboo Fiber :

Bamboo Original Fiber is a natural bamboo fiber made using a combination of physical and chemical methods.

Bamboo Original Fiber is a new type of natural fiber, made using a combination of physical and chemical methods. It differs fundamentally from bamboo pulp fiber, which belongs to chemical fibers. The successful development of Bamboo Original Fiber marks the birth of a new natural fiber that is in line with the national industry development policy. Natural Bamboo Original Fiber has excellent properties such as moisture absorption, breathability, antibacterial and deodorizing effects, and UV protection.

The production process includes the steps of bamboo logs → bamboo chips → steaming of bamboo chips → crushing and decomposition → biological enzyme degumming → fiber combing → textile fiber.

Chemical Bamboo Fiber -Bamboo Pulp Fiber:

Bamboo pulp fiber is made by turning bamboo chips into pulp, then making pulp into pulp cakes and wet-spinning them into fibers. The production process is similar to that of viscose. However, the natural characteristics of bamboo are destroyed during the manufacturing process, and the fiber’s deodorizing, antibacterial, and UV protection functions are significantly reduced.

Chemical Bamboo Fiber -Bamboo Charcoal Fiber:

Bamboo charcoal fiber is made by adding nano-grade bamboo charcoal powder to viscose spinning solution and then spinning the fiber using a process similar to conventional spinning.

Source:Socks Industry International Co.Ltd

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Today's KNOWLEDGE Share: DMA

Today's KNOWLEDGE Share:

DMA

I praised the incredible power of Dynamic Rheology to study polymer flow behaviour and the polymer molecular structure.

To be totally fair, I have to also acknowledge the equally valuable power of Dynamic Mechanical Analysis (DMA or DMTA).

The principle is strictly the same, with an in-phase and out of phase response. The test is however conducted on solid samples (tension, torsion, bending...) and is most useful in a Temperature sweep approach, ideally from cryogenic temperatures up and above Tg.

The data produced (in addition to the Tg value) can help assess the damping characteristics of the polymer for NVH aspects for instance.

The observation of multiple sub-Tg transitions is of great spectroscopic interest to understand molecular motions and segmental movements. These transitions are the key reason for toughness observed below Tg in many polymers, a performance aspect we rely upon everyday in our plastic parts.

Subtle plasticizing or anti-plasticizing mechanisms can be studied, highlighting often dramatic changes in mechanical performance with addition of a few tenth percent of additives or just due to moisture.

Source:VITO LEO

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#plastics #dma #rheology #tg #temperature #meltflow #polymerscience

UN Outlines the Changes Required to End Plastic Pollution and Create Circular Economy

Plastic pollution could reduce by 80 per cent by 2040 if countries and companies make deep policy and market shifts using existing technologies, according to a new report by UN Environment Programme (UNEP).

The report is released ahead of a second round of negotiations in Paris on a global agreement to beat plastic pollution and outlines the magnitude and nature of the changes required to end plastic pollution and create a circular economy.

Three Market Shifts Needed– Reuse, Recycle and Reorient

“The way we produce, use and dispose of plastics is polluting ecosystems, creating risks for human health and destabilizing the climate,” said Inger Andersen, UNEP executive director. “This UNEP report lays out a roadmap to dramatically reduce these risks through adopting a circular approach that keeps plastics out of ecosystems, out of our bodies and in the economy. If we follow this roadmap, including in negotiations on the plastic pollution deal, we can deliver major economic, social and environmental wins.”

To slash plastic pollution by 80 percent globally by 2040, the report suggests first eliminating problematic and unnecessary plastics to reduce the size of the problem. Subsequently, the report calls for three market shifts – reuse, recycle and reorient and diversify products:

1. Reuse: Promoting reuse options, including refillable bottles, bulk dispensers, deposit-return-schemes, packaging take-back schemes etc., can reduce 30 percent of plastic pollution by 2040. To realize its potential, governments must help build a stronger business case for reusables
2. Recycle: Reducing plastic pollution by an additional 20 percent by 2040 can be achieved if recycling becomes a more stable and profitable venture. Removing fossil fuels subsidies, enforcing design guidelines to enhance recyclability, and other measures would increase the share of economically recyclable plastics from 21 to 50 percent
3. Reorient and diversify: Careful replacement of products such as plastic wrappers, sachets and takeaway items with products made from alternative materials (such as paper or compostable materials) can deliver an additional 17 percent decrease in plastic pollution

Save Trillions with the Economy Shift

Even with the measures above, 100 million metric tons of plastics from single-use and short-lived products will still need to be safely dealt with annually by 2040 – together with a significant legacy of existing plastic pollution. This can be addressed by setting and implementing design and safety standards for disposing of non-recyclable plastic waste, and by making manufacturers responsible for products shedding microplastics, among others.

Overall, the shift to a circular economy would result in USD 1.27 trillion in savings, considering costs and recycling revenues. A further USD 3.25 trillion would be saved from avoided externalities such as health, climate, air pollution, marine ecosystem degradation, and litigation-related costs. This shift could also result in a net increase of 700,000 jobs by 2040, mostly in low-income countries, significantly improving the livelihoods of millions of workers in informal settings.

Investment costs for the recommended systemic change are significant, but below the spending without this systemic change: USD 65 billion per year as opposed to USD 113 billion per year. Much of this can be mobilized by shifting planned investments for new production facilities ¬– no longer needed through reduction in material needs – or a levy on virgin plastic production into the necessary circular infrastructure. Yet time is of the essence: a five-year delay may lead to an increase of 80 million metric tons of plastic pollution by 2040.

The highest costs in both a throwaway and circular economy are operational. With regulation to ensure plastics are designed to be circular, Extended Producer Responsibility (EPR) schemes can cover these operational costs of ensuring the system’s circularity through requiring producers to finance the collection, recycling and responsible end-of-life disposal of plastic products.

Integrate Regulations & Policies Tackling Actions Across Life Cycle

Internationally agreed policies can help overcome the limits of national planning and business action, sustain a flourishing circular global plastics economy, unlock business opportunities and create jobs. These may include agreed criteria for plastic products that could be banned, a cross-border knowledge baseline, rules on necessary minimum operating standards of EPR schemes and other standards.

The report recommends that a global fiscal framework could be part of international policies to enable recycled materials to compete on a level playing field with virgin materials, create an economy of scale for solutions, and establish monitoring systems and financing mechanisms.

Crucially, policymakers are encouraged to embrace an approach that integrates regulatory instruments and policies tackling actions across the life cycle, as these are mutually reinforcing towards the goal of transforming the economy. For example, design rules to make products economically recyclable can be combined with targets to incorporate recycled content and fiscal incentives for recycling plants.

The report also addresses specific policies, including standards for design, safety, and compostable and biodegradable plastics; targets for minimum recycling; EPR schemes; taxes; bans; communication strategies; public procurement, and labeling.

Source: UN Environment Programme/Omnexus.specialchem.com
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#carbonneutral #plasticsindustry #plasticpollution #plasticwaste #circulareconomy #unitednations

Today's KNOWLEDGE Share: High strain composites for the space industry!

Today's KNOWLEDGE Share:

High strain composites for the space industry! 

Leveraging their extensive experience with spacecraft systems and components, Opterus Research and Development design and manufacture deployable booms, hinges, antennas, membrane structures, solar sails, light shades, and more! 

In this post you can see some examples of their recent developments: 

1) Trussed Collapsible Tubular Mast (T-CTM): Opterus’ most robust boom architecture, the patent pending TCTM features truss class structural performance. Offering the highest stiffness, strength, and precision this highly scalable boom architecture is ideal for large deployable space structures supporting high loads.

2)Collapsible Tubular Mast (CTM): Their most precise boom architecture, the patent pending CTM features a fully enclosed lenticular cross section. This architecture enables shorter boom transition lengths for greater compaction and greater strength and stiffness enabled by the closed cross section. Scalable to small and large cross section diameters, Opterus’ multi-step CTM manufacturing process is highly adaptable to a variety of boom scales with minimal lead time and cost.

3) Lenticular Offset Composite (LOC) Hinge: Derived from Opterus’ high strain composite slit-tube booms, the patent pending composite flexure hinge is a molded composite hinge that facilitates deployment via stored strain energy. The simple composite construction is low mass, cost effective and rapidly manufacturable.

Definitely one of the most distinct composite projects we have ever seen! Truly groundbreaking! Congratulations to the team! 

Source:#managingcomposites #thenativelab

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#composites #carbonfiber #manufacturing #design #development #deploy #hinges #antennas

New Catalyst to Support Acetic Acid Production from CO-sourced Captured Carbon

 Northwestern University researchers work with an international team of collaborators to create acetic acid out of carbon monoxide derived from captured carbon. The innovation, which uses a novel catalyst created in the lab of Professor Ted Sargent, could spur new interest in carbon capture and storage.

The need to capture CO2 and transport it for permanent storage or conversion into valued end uses is a national priority recently identified in the Bipartisan Infrastructure Law to move toward net-zero greenhouse gas emissions by 2050.

“Carbon capture is feasible today from a technical point of view, but not yet from an economic point of view,” Sargent said. “By using electrochemistry to convert captured carbon into products with established markets, we provide new pathways to improving these economics, as well as a more sustainable source for the industrial chemicals that we still need.”

“Acetic acid in vinegar needs to come from biological sources via fermentation because it’s consumed by humans,” Wicks said. “But about 90% of the acetic acid market is for feedstock in the manufacture of paints, coatings, adhesives and other products. Production at this scale is primarily derived from methanol, which comes from fossil fuels.”

Lifecycle assessment databases showed the team that for every kilogram of acetic acid produced from methanol, the process releases 1.6 kg of CO2.

Selectivity of Catalyst as Major Challenge:

Their alternative method takes place via a two-step process: first, captured gaseous CO2 is passed through an electrolyzer, where it reacts with water and electrons to form carbon monoxide (CO). Gaseous CO is then passed through a second electrolyzer, where another catalyst transforms it into various molecules containing two or more carbon atoms.

“A major challenge that we face is selectivity,” Wicks said. “Most of the catalysts used for this second step facilitate multiple simultaneous reactions, which leads to a mix of different two-carbon products that can be hard to separate and purify. What we tried to do here was set up conditions that favor one product above all others.”

In the paper, the team reports a faradic efficiency of 91%, meaning that 91 out of every 100 electrons pumped into the electrolyzers end up in the desired product, in this case, acetic acid.

“That’s the highest faradic efficiency for any multi-carbon product at a scalable current density we’ve seen reported,” Wicks said. “For example, catalysts targeting ethylene typically max out around 70% to 80%, so we’re significantly higher than that.”

The new catalyst also appears to be relatively stable: while the faradic efficiency of some catalysts tends to degrade over time, the team showed that it remained at a high level of 85% even after 820 hours of operation.

Source: Northwestern University/www.polymer-additives.speicialchem.com

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Today's KNOWLEDGE Share:Transient Frozen layer thickness

Today's KNOWLEDGE Share:

Transient Frozen layer thickness
When trying to model Injection Molding one has to determine the transient frozen layer thickness.And it is more tricky than most might think.

For amorphous polymers the best transition temperature would be available straight from the PvT data and will even include the important pressure dependence. It will however not include any cooling rate dependence and Tg is extremely sensitive to cooling rate, as people observe daily with DSC
PvT is essentially measured in a quiescent state close to thermodynamic equilibrium (very slow heat/cool rates).

For semi-crystalline materials the problem is worse. We need to capture the crystallization temperature which is pressure dependent also (that can be seen in PvT) but extremely dependent on cooling rate (crystallization kinetics aspects).
Furthermore, the strong nucleation effect of shear-stress close to the outer layers will dramatically increase, locally, this transition temperature. Which means the transition temperature will be very different from skin to core.

In essence, there is not such a thing as ONE no flow temperature or transition temperature.
To preserve mass balance in molding simulation it will also be of key importance to perfectly "sync" the phase change for all physical properties (PvT, thermal data, viscosity,...).

We still have a long way to go to fully capture this complex physics in our beloved commercial software tools.The best attempt I know of, was an old Research Release version of Moldflow, work I was involved in) including explicit crystallization kinetics and implementing "dynamic" PvT (transition zone driven by real kinetics), with full sync of all other variables.

Source:VITO LEO
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#polymers #plasticsengineering #injectionmolding #temperature #moldflow #frozen