Today's KNOWLEDGE Share:Differential shrinkage driven Warpage problem

Today's KNOWLEDGE Share

How to experimentally spot a differential shrinkage driven warpage problem ?

If you are molding a relatively uniform thickness part and suffer from warpage, there is a nice trick to experimentally separate the contribution of differential shrinkage from other sources of problems (differential cooling, anisotropy).

Just make parts that are roughly full (say, 99% full), with zero packing (no pressure, no time). By not packing, you avoid packing one area better than another (for instance overpacking the gate area vs. distant areas). As a result you have a lighter part, with sink marks all over and voids, but with essentially NO DIFFERENTIAL SHRINKAGE. If this "short shot" is flatter than your packed part, you have experimentally demonstrated a strong contribution from "uneven packing", i.e. differential shrinkage.

Source:Vito leo

Today's KNOWLEDGE Share:carbon fibre with high tensile modulus and enhanced strength

Today's KNOWLEDGE Share

Toray develops Torayca™ M46X carbon fibre with high tensile modulus and enhanced strength

Toray Industries, Inc. announced that it has developed Torayca™ M46X carbon fibre. The new offering is around 20% stronger than others in the Torayca™ MX series while maintaining a high tensile modulus. Utilizing Torayca™ M46X reduces the weight of carbon fibre-reinforced plastic materials, lowering its environmental impact.

Typically, there is a trade-off between the tensile modulus and strength of carbon fibre. Boosting the strength while maintaining the modulus of carbon fibres with a tensile modulus exceeding 350 GPa presents technological challenges. However, the sporting and leisure goods market demands both qualities to maintain performance while utilizing less carbon fibre to lower the weight of molded parts.

Toray developed Torayca™ M46X by pushing the structural control technology envelope. Nano-level controls of the graphite crystallite structure inside fibres resulted in an ultrafine, ultrahigh orientation producing carbon fibre that is more than 20% stronger than conventional materials while maintaining its tensile modulus.

The company will also deploy Torayca™ M46X prepreg, with the resin matrix utilizing the proprietary NANOALLOY®1 microstructure control technology. The new product will significantly enhance compressive strength to boost stiffness while retaining strength, reducing the weight of finished products and broadening design flexibility.

Developing high-performance carbon fibres with a high tensile modulus exceeding 350 GPa began with Torayca™ M40 with graphitized yarn2. Successors were Torayca™ M40J in 1984 and Torayca™ M46J in 1986 in response to robust demand for the high-modulus Torayca™ MJ carbon fibre series. Toray continued to develop technologies to balance the tensile strength and modulus. The Torayca™ MX series was created by applying technologies to control graphite crystallite structures and orientations3 inside fibres. The first offering in this series was the Torayca™ M40X, launched in 2018. This product has since earned a solid reputation as a high-performance carbon fibre and prepreg (a resin-impregnated intermediate base material) matching market requirements.

Toray will continue developing new products that help transform the economy through the enhanced performance and processability of carbon fibre and prepreg.

1. Nanoalloy is a Toray-developed microstructure control technology that can dramatically improve properties compared with conventional materials by minutely dispersing multiple polymers on a nanometric scale.

2. Graphitized yarn is a carbon fibre heat-treated at high temperature in a graphitization furnace.

3. Graphite crystallite structures and orientations refers to graphite crystallite structures growing, and orientation increasing after treatment at high temperature in a graphitization furnace.

Source:Toray/jeccomposites.com

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Today's KNOWLEDGE Share: Composite molding compoun

Today's KNOWLEDGE Share

Composite molding compound replaces Invar for lightweight small satellite structures!

Patz Materials and Technologies and Lawrence Livermore National Laboratory developed a new monolithic optics housing with 80% less weight, near-zero CTE and the high-volume manufacturing required for commercial space!

"In 2021, Patz Materials and LLNL teamed up to replace Invar in these monolithic optic housings with a molding compound comprising PMT-F16 epoxy resin modified with carbon nanotubes (CNT) and reinforced with 6K tow high modulus carbon fiber with 60% fiber content. The project demonstrated not only the ability to meet all metallic housing performance requirements at a fraction of the weight, but also provided even further benefits when the housing was redesigned to take advantage of the composite material and molding process."

Source:managingcomposites/thenativelab

Today's KNOWLEDGE Share:Fountain flow free surface

Today's KNOWLEDGE Share

Any surface particle on a molded part used to belong to the Fountain Flow free surface.

Free surfaces for a visco-elastic material typically suffer from flow instabilities, and these end-up creating surface defects on your molded part. High front velocity and especially flow front acceleration/deceleration will trigger flow instabilities and defects.

This is why the gate area and the end of flow (see picture) are so prone to surface defects. We do have the highest velocity at the gate and a potential extreme velocity at the end of flow (or slowdown due to switchover).

"Tiger Stripes" are a well known defect due to Fountain Flow instabilities triggered by a change of flowfront speed.

Source:Vito leo

Researchers Develop New Catalyst that Completely Breaks Down Nylon-6 within Minutes

Northwestern University chemists have developed a new catalyst that quickly, cleanly and completely breaks down nylon-6 in a matter of minutes — without generating harmful byproducts.

The process does not require toxic solvents, expensive materials or extreme conditions, making it practical for everyday applications.

Not only could this new catalyst play an important role in environmental remediation, it also could perform the first step in upcycling nylon-6 wastes into higher-value products.

Up to 1 Mn Tons of Fishing Gear is Abandoned in the Ocean Each Year

From clothing to carpet to seat belts, nylon-6 is found in a variety of materials that most people use every day. But, when people are done with these materials, they end up in landfills or worse: loose in the environment, including the ocean. According to the World Wildlife Federation, up to 1 million tons of fishing gear is abandoned in the ocean each year, with fishing nets composed of nylon-6 making up at least 46% of the Great Pacific Garbage Patch.

“The whole world is aware of the plastic problem,” said Northwestern’s Tobin Marks, the study’s senior author. “Plastic is a part of our society; we use so much of it. But the problem is: What do we do when we’re finished with it? Ideally, we wouldn’t burn it or put it into landfills. We would recycle it. We’re developing catalysts that deconstruct these polymers, returning them to their original form, so they can be reused.”

“Fishing nets lose quality after a couple years of use,” said Liwei Ye, the paper’s lead first author who is a postdoctoral fellow in Marks’ laboratory. “They become so water-logged that it’s difficult to pull them out of the ocean. And they are so cheap to replace that people just leave them in the water and buy new ones.”

“There is a lot of garbage in the ocean,” Marks added. “Cardboard and food waste biodegrades. Metals sink to the bottom. Then we are left with the plastics.”

Marks is the Charles E. and Emma H. Morrison professor of Chemistry and Vladimir N. Ipatieff professor of Catalytic Chemistry at Northwestern’s Weinberg College of Arts and Sciences and a professor of materials science and engineering at Northwestern’s McCormick School of Engineering.

Source: Northwestern University/Omnexus-specialchem

Today's KNOWLEDGE Share: HEMP

Today's KNOWLEDGE Share:

Interesting facts about hemp.

1. One hectare of hemp releases as much oxygen as 25 hectares of forest.
2. From one hectare of hemp you can get as much paper as from 4 hectares of wood.
3. While hemp can be turned into paper 8 times (recycle), wood can be turned into papers 3 times. Hemp paper is the best and strongest.
4. Hemp grows in 4 months and the tree grows in 20-50 years.
5. Hemp flower is a real ray trap. Hemp planters clean the air.
6. Hemp can be grown anywhere in the world, it needs very little water.
Also, since it can protect itself from pesticides, it doesn't need pesticides.
7. Hemp textiles surpass even linen products in their properties.
8. Hemp is an ideal plant to make ropes, ropes, laces, bags, shoes, headwear.
9. Hemp is banned in many countries. But technically hemp is drug-free.
10. The protein value of hemp seed is very high and the two fatty acids in it are no longer found anywhere else in nature.
11. It's much cheaper to produce hemp than soybeans.
12. Animals fed hemp don't need hormonal support.
13. All plastic products can be made from hemp, and hemp plastic is environmentally friendly and fully biodegradable.
14. If the car body is made of hemp-based compound, it will be 10 times stronger.
15. Hemp can also be used for insulation of buildings, it is durable, cheap and flexible.
16. Soap and cosmetics made of hemp do not pollute water, so it is completely environmentally friendly.

Source:Organic consumers association of Australia

Today's KNOWLEDGE Share:Bio based Nylon66

Today's KNOWLEDGE Share

OzoneBio Produces Nylon66 Using Adipic Acid Derived from Wood Waste:

OzoneBio, a Canadian cleantech start-up recently produced the wood waste derived Nylon66. It is claimed to be the only and first in the world Nylon66 made with wood derived bio-adipic acid.

Zombie Cells Eliminate the Need of Costly Metal Catalysts:

Their revolutionary approach utilizes “Zombie cells” catalysis technology to convert wood waste into premium-grade materials and products with zero emissions, reducing environmental impact from the very start.

OzoneBio is currently focused on improving and expanding their bioplastic production capabilities. Their innovative technology has garnered attention from several major chemical corporations and renowned sports apparel companies interested in more sustainable materials.

In 2021, OzoneBio completed the highly competitive IndieBio incubator program located in Silicon Valley, which accelerates emerging biotechnology and life science companies. After this achievement, OzoneBio became part of the Life Science Innovation Hub in Calgary in 2022. At this hub, they are concentrating efforts on commercializing their zero-emission bioplastic alternative to Nylon66, now trademarked as OzoNyl. OzoneBio aims to facilitate a shift toward a green, circular economic model through this technology.

Source: OzoneBio/omnexus-specialchem