Today's KNOWLEDGE Share:

CarbonCast: C-GRID carbon fiber grid used in precast insulated wall panels

C-GRID is a carbon fiber grid, the enabling technology that gives CarbonCast products their outstanding strength and thermal efficiency.

How was C-GRID developed?

C-GRID was first developed by Chomarat over 20 years ago in collaboration with Oldcastle Precast, a founding member of AltusGroup. C-GRID’s strength, non-corrosiveness and ultra-low thermal conductivity made it an idea connector truss for insulated precast wall panels.

Manufacturing technique produces C-GRID

C-GRID is formed in a continuous rotary laid-scrim process in which machine and cross direction carbon tows are aligned in a 0/90-degree orientation and then impregnated with a proprietary thermoset epoxy resin system.

Strength:

C-GRID’s strength is achieved by selecting large carbon tows with high tensile strength values and impregnating them in our proprietary epoxy resin system. 

Depending on the requirements of the application, we can design specific C-GRID constructions to meet requirements. Adjusting the tow size and spacing controls the tensile strength of the reinforcement per square foot.

What are the thermal conductivity characteristics of C-GRID, and how does that benefit the insulated precast panel in?

As a nonmetallic connector, C-GRID has the benefit of ultra-low thermal conductivity. This enables precast producers to manufacture highly efficient insulated wall panels that significantly lower annual heating and cooling costs.

Chemical composition of the epoxy resin used in C-GRID:

Chomarat developed a two-component high Tg epoxy system for C-GRID that helps precasters meet fire rating requirements for precast insulated wall panels.

How is C-GRID’s design tailored for specific applications?

With a range of carbon tow strand size from 3K to 60K and strand spacing of 1 inch to 4 inches, we can offer engineers a very wide range of strengths and grid apertures to meet their specific requirements. 

Source:John Leatham-Chomarat/JEC Composites

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#composites #panels #epoxy #carbonfiber #thermalconductivity #noncorrosive

Today's KNOWLEDGE Share:Notched testing of sandwich composites

Today's KNOWLEDGE Share:

Notched testing of sandwich composites: The sandwich open-hole flexure test!

"A primary reason for having two notch sensitivity test methods for composite laminates is the difference in failure modes and resulting notch sensitivities under tension and compression loading. Sandwich composites are commonly subjected to flexural loading, resulting in a tension-loaded facesheet and a compression-loaded facesheet. When using fiber-reinforced composite facesheets, the compression-loaded facesheet typically fails first." 

"Additionally, sandwich composites are used in compression-loading applications, and their notched strengths under compression and flexural loading are typically not the same. Therefore, even though failure primarily occurs in compression-loaded facesheets, two separate test methods are desired." 

"The new sandwich OHF test standard is designated as an ASTM standard practice, as it provides only supplemental instructions for modifying the sandwich long beam flexure test method, ASTM D72495, for use with open-hole sandwich specimens. As in all other ASTM notch sensitivity tests for composite laminates and sandwich composites, a specimen width-to-hole diameter ratio of 6:1 is used. This ratio has been widely accepted in the aerospace composites community for producing acceptable notched strength reductions while minimizing the interaction between the centrally located open through-hole and the specimen edges." 

Source:#managingcomposites/#thenativelab

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#composites #testing #notch #aerospace #laminate

Today's KNOWLEDGE share:Warpage of a GF 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 Coefficient of Thermal Expansion 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

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#plastics #polymerscience #injectionmolding #moisture #glassfiber #nylon #warpage #thermal

Today's KNOWLEDGE Share: Closed-look recycling

Today's KNOWLEDGE Share:

Closed-look recycling

Eastman announces the successful completion of the closed-loop recycling project for automotive mixed plastic waste. Through a collaborative effort, Eastman, the United States Automotive Materials Partnership LLC (USAMP), automotive recycler PADNOS, and global automotive interior supplier Yanfeng demonstrated first-of-its-kind plastic recycling from the by-product of shredding end-of-life vehicles.

When automobiles are at the end of their life, metals, tires and glass account for 80-90% of the materials that can be recycled through traditional mechanical #recycling streams. The other 10-20%, referred to as automotive shredder residue (ASR), consists of mixed plastic and other non recycled materials that currently end up in landfills or are recovered through waste-to-energy technologies.

Under this initiative, PADNOS supplied a plastic-rich fraction of ASR as a sustainable feedstock to Eastman carbon renewal technology (CRT). Eastman successfully demonstrated the addition and conversion of that ASR feedstock into a synthesis gas (syngas), which is subsequently used downstream in the production of its polyester and cellulosic thermoplastics. Resins from this production process were further formulated and then supplied to Yanfeng. The parts molded by Yanfeng for demonstration were successfully tested to meet a variety of OEM — Ford Motor Company, General Motors, and Stellantis — requirements, thereby demonstrating proof of concept for a truly circular solution.

The study proved the feasibility of Eastman’s carbon renewal technology (CRT), one of Eastman’s two molecular recycling technologies, which breaks down the plastic-rich ASR into molecular building blocks. By recycling these complex plastics in CRT, Eastman can replace fossil-based feedstock and create polymers without compromising performance for use in new automotive applications.

In addition to diverting waste from landfills, USAMP, a subsidiary of USCAR - US Council for Automotive Research, also sees the potential for energy savings and reduced overall greenhouse gas emissions. Deloitte Consulting estimates more than 10 billion pounds of ASR is sent to landfills globally each year.

“This is a prime example of how collaboration across the value chain is essential to making material circularity mainstream,” said Stephen Crawford, Eastman executive vice president, manufacturing, and chief sustainability officer. “Modern cars are made with approximately 50% plastic by volume on average, and this number is only expected to increase as automotive manufacturers continue to seek lighter electric vehicles. We’re demonstrating a future where automotive hard-to-recycle plastics and fibers are diverted from landfills and recycled to produce new automotive parts.”

Source:EASTMAN

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#plastics #plasticwastemanagement  #innovation #automotive #recycling  #circulareconomy #closedloop #automotiveindustry

Today's KNOWLEDGE Share:Engineered Bamboo Window Wall & Curtain Wall

Today's KNOWLEDGE Share:

Engineered Bamboo Window Wall & Curtain Wall

Bamboo Sequesters 10x Carbon vs Trees:

Bamboo has a unique geometric growth curve that makes it 10x faster than tree-based CO2 drawdown. Intensively harvested, our bamboo can sequester up to 1.76 tones CO2/clump/year, or up to 362 tones/hectare/year in an optimally managed farm. SEB (Structural Engineered Bamboo): Estimated Carbon Sequestration: 1,316 kg/m3 = of CO2(LCA)

Bamboo Produces 37% More Oxygen:

Guadua Bamboo not only sequesters carbon, but it also produces oxygen as it grows. Guadua bamboo produces up to 37% more oxygen than trees! During the industrial revolution and even today massive quantities of natural tree growth has been removed around the world. Timber construction is considered sustainable when compared to concrete and steel, but it is nowhere near the sustainability case for bamboo especially when accounting for the already depleted natural forests.

Bamboo is a Rapidly Renewable Resource:

The Guadua Bamboo integrated into our products is documented as a Rapidly Renewable Resource. Harvest begins at 6-8 years and continues every year after through the life of the bamboo plant. This continuous harvest produces 14 Tons of usable bamboo fiber/Acre/Year. The fiber yield of mature bamboo is 6 times the usable biomass of timber forests over a 25-30 year timeline (The typical growing period for softwood trees used in structural products) such as: Spruce, Southern Yellow Pine, and Douglas Fir.

Bamboo Stabilizes and Nourishes the Soil:

Guadua bamboo's root system stays intact throughout growth and harvest. When timber is harvested the root system dies and causes drastic soil instability, and the consequence is top soil erosion. Extreme cases of this have occurred all over the world in places such as India, Asia, and Central/South America. When old growth and timber farms are removed the quality top soil is lost and regrowth of any form of vegetation is limited.

Source:Adam Racomelara l Shorebird Consulting

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#naturalfibers #bamboo #bambooproducts #sequestration #sustainability #growth #construction #biomass #soilstabilization

Today's KNOWLEDGE Share:Carbon Fiber phone case

Today's KNOWLEDGE Share:

Carbon Fiber phone case:

Experts in the mobile phone industry know that carbon fiber material is an expensive raw material.Carbon fiber (CF) is a new type of fiber material with high strength and high modulus fiber containing more than 95% of the carbon content. Carbon fiber is "soft outside and rigid inside", and the quality is lighter than metal aluminum, but the strength is higher than steel, and it has the characteristics of corrosion resistance, high modulus and friction resistance, which is an important material in national defense and civil industry.

Carbon fiber mobile phone case has a super thin bare phone case with waterproof, friction resistance, anti-fall characteristics. Some companies currently showing on the iphone series,they currently produce the real carbon fiber mobile phone cases of the iphone, samsung, huawei,moto, oppo, etc. 

Source:Kataria Jiang

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#carbonfiber #phonecase #userfriendly #iphone #huawei

Today's KNOWLEDGE Share:Nylon Structure vs. Moisture Absorption

Today's KNOWLEDGE Share:

Nylon Structure vs. Moisture Absorption

 

Nylon, also known as polyamide (PA), resins are a diverse group of materials. The versatility of polyamide makes this family of polymers one of the most widely used thermoplastics. Could Wallace Carothers ever have anticipated the significance of his material invention?

 

The molecular architecture, and especially the ratio of carbon atoms to amide functionality, is what gives each different type of polyamide structure its unique characteristics. This structural relationship affects all the properties of the material, including:

 

·     Mechanical properties

·     Thermal characteristics

·     Degradation resistance

·     Water absorption

 

Water absorption is an extremely important metric for polyamide materials since the fundamental properties of these materials are different at varying levels of water absorption. The level of water absorption within aliphatic polyamides is directly related to the ratio of olefinic content to amide functionality. The higher the relative proportion of olefinic structure, the less the water absorption, which in turn results in a lower level of property alteration.

 

Source:The Madison group

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#plastics #nylon #polyamide ##materialsscience #materialselection #polymers #failureanalysis #moisture