Today's KNOWLEDGE Share: TYPES OF FIBERS

Today's KNOWLEDGE Share:

TYPES OF FIBERS

The different fiber types that can be used as reinforcement phases in composite materials.

Today we would like to share with you the definitions and examples of the most common fibers used in the industry! 

Carbon fibers are long and thin strands of material with about 0.005-0.010 mm in diameter, composed mostly of carbon atoms (more than 90% content). The carbon atoms are bonded together in microscopic crystals that are more or less aligned parallel to the long axis of the fiber. The crystal alignment makes the fiber incredibly strong for its size. 

Glass fiber is a non-metallic material made from extremely fine fibers of glass. The base ingredients of glass fibers are forms of silica, mainly sand, limestone, stone ash and borax. It is also considered the oldest, and most familiar, performance fiber. 

Aramid (short for “aromatic polyamide”) fibers are synthetic fibers in which the fiber-forming substance is a long-chain synthetic polyamide that has at least 85% of the amide linkages attached directly to two aromatic rings. Its molecules are linked by strong hydrogen bonds that transfer mechanical stress very efficiently, making it possible to use chains of relatively low molecular weight. The most famous aramid fiber is DuPont's Kevlar. 

Polymer fibers are a subset of artificial fibers, which are based on synthetic chemicals rather than arising from natural materials by a purely physical process. Examples: PE fibers (Dyneema, Spectra), PP fibers (Innegra), PET fibers, polyester fibers and many others. Aramid fibers are also considered polymeric. 

Natural fibers are fibers that are produced by geological processes, or from the bodies of plants or animals. Examples: Hemp, jute, flax, kenaf, basalt, cotton,lyocell etc. 

Other fibers that we can mention: Boron fibers, metallic fibers (aluminum, titanium, steel) and ceramic oxide fibers. 

Now imagine the amount of possibilities when it comes to creating hybrid fabrics! 

Source:#managingcomposites #thenativelab

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#composites #fibers #fiberglass #carbonfiber #kevlar #lyocell #jute #flax #cotton #metallicfibers #dyneema #petfiber #basalt #hemp

Solvay Launches New High-heat Polymer for EV Battery Components

Solvay has announced the introduction of a new high-heat and flame-retardant grade in the company’s Xydar® liquid crystal polymers (LCP) portfolio, which is designed to meet critical safety demands in EV battery components.

Retains Insulation Upon Exposure to 400°C for 30 Minutes:

The new Xydar® LCP G-330 HH material addresses challenging thermal and insulation requirements and is targeted particularly at battery module plates of EV models operating with higher voltage systems.

“As automakers are moving from 400V to 800V on next-generation electric vehicles, new regulations in Europe, China, the United States and other countries are increasing the demand on battery components to withstand temperatures from 300°C to 1000°C for an extended window of up to 15 minutes,” states Brian Baleno, head of marketing, Transportation at Solvay Materials. “Appropriate materials are expected to retain a level of electrical insulation protection that will provide sufficient time for passengers to exit the vehicle in a thermal runaway event. Our new Xydar® LCP grade combines this high safety potential with exceptional processability."

Xydar® LCP G-330 HH is a glass-filled LCP for injection molding capable of retaining its electrical insulation upon exposure to 400°C for 30 minutes. Xydar® LCP is an inherently flame-retardant polymer, without the use of halogen or bromine additives. In addition, it offers exceptional flowability and helps battery designers achieve thinner parts than possible with incumbent battery module insulation materials, such as polycarbonates or aerogels. It has been successfully tested with plates molded in typical dimensions of 100 x 150 x 0.5 mm.

Extends Portfolio of Battery Solutions:

Xydar® LCP has a proven fit in many electrical and electronic as well as coating applications. Besides automotive lighting components, sensors, solenoids and connectors, advanced examples in e-mobility include thin-wall slot liners used in the rotor design of an electric drive traction motor.

Xydar® LCP G-330 HH extends the portfolio of Solvay’s battery solutions, which also includes Solef® PVDF for binders and separators, Ryton® PPS for coolant line connectors and vents, and Amodel® PPA for connectors and busbars.

Source: Solvay/Omnexus.specialchem.com

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#solvay #lcp #polymers #evbattery #insulation #electrical #electronics #materialsscience

Today's KNOWLEDGE Share:Waste Metals

Today's KNOWLEDGE Share:

Waste Metals

Half of all the metals used today have a lifespan of fewer than 10 years.

As a society, we use around 61 different metals.However, more than half of them will end in a landfill or in a recycling yard within ten years.This speaks to the enormous amount of wastage that we accrue as a civilization.

Billions of tonnes of metals are mined each year, which accounts for 8 % of all greenhouse gas emissions. Now, if we could save the metals that we discard, it could bring down both mining and greenhouse gas emissions.

The results are from an industrial ecology group at Yale University.

The only notable exception to this list is gold, which continues to be maintained and reused for centuries.Perhaps we should start mandating metal recycling and make it profitable to extract waste metals from landfills.

Source:http://ow.ly/7iNj50JmBGh

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#metals #wastemanagement #landfills #gold #mining #co2emissions

Today's KNOWLEDGE Share:Earthquake Effect on Spherical Storage Tanks

Today's KNOWLEDGE Share:

Earthquake Effect on Spherical Storage Tanks:

A major earthquake of magnitude 9 (Richter scale) hits eastern Japan at 14:46, a leak on a LPG pipe is detected at 15 h 35 in a refinery located within a large petrochemical complex in the bay of Tokyo . At 15 h 48, the leak ignites and spreads to the adjacent spherical tanks stocking liquefied butane and butylene.
The rapid development of the fire causes the fall of most tanks (broken foot support) and a cascade of BLEVE (BOILING LIQUID EXPANDING VAPOUR EXPLOSIONS).

The initial leak of LPG, by crushing of a pipe, resulted from the collapse of an overhanging sphere filled with water for a hydraulic test after the 1st aftershock of the main earthquake.
The main earthquake weakened the supporting structure by cracking the crosspieces, and then led to the failure of the support legs during the 1st aftershock of magnitude 7.2 at 3.15 pm.

What Went Wrong???
The design of the structure adapted to the seismic risk for a gas (LPG) load did not take into account the overload due to the filling of the tank with water.
In addition, the automatic safety shutdown of the gas transport pipeline triggered by the seismometers was inoperative on this part of the pipeline, as the automatic cut-off valve was shunted open following earlier problems with the pneumatic control.(big mistake).The temporary procedure of manually closing this valve pending repair could not be implemented due to a large LPG pool.
As a result, the fire was uncontrollable.

What We Learned From This Accident?
-Reduction of the duration of the water presence in the spheres in hydraulic tests (judged abnormally long during the accident) ;
-In the new sphere design, additional loads from water, especially seismic loads, should be taken into account.
-Systematic isolation and draining of a gas pipeline close to the spheres under hydraulic test.
-Increasing the flexibility of new on site gas transport pipelines to accommodate large multidirectional displacements during major earthquakes.
- Emergency shut-off valves are critical equipment, their faults should be repaired in a short time.

Source:https://lnkd.in/dNpCnuw4/ Technical Engineering Portal
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#LPG #sphericaltanks #fire #earthquake #seismicloads #oil #chemical #propane #butane #butylene #Bleve #gas #refinery #petrochemical #engineering #safety #design #pipeline
#development #transport

Today's KNOWLEDGE Share: Integral Hinge Material Characteristics

Today's KNOWLEDGE Share:

Integral Hinge Material Characteristics:
I have worked on a number of projects, both material selection and failure analysis, involving an integral hinge. An integral hinge, also known as a living hinge, is a thin flexible web that connects two relatively rigid wall sections. The living hinge is formed when partially oriented plastic is drawn cold and flexed for the first time. Because of its molecular structure and flexural fatigue properties, polypropylene is widely used in integral hinge applications. Well oriented polypropylene webs are considered to have virtually unlimited fold endurance, assuming appropriate part design, resin, and molding conditions are utilized.

When reviewing the commercially available polypropylene resins, it is helpful to consider which compositional characteristics maximize the material’s utility for a living hinge application.

Typically, fillers and reinforcements compounded into polypropylene will negatively impact the performance of the integral hinge. Fillers and reinforcements reduce the elongation at yield of the material, which accounts for this reduction in performance.

A superior molded integral hinge relies on the ability to freeze polymer orientation during molding prior to cold drawing. A number of polymer variables affect the amount of frozen orientation.

Molecular Weight: High molecular weight is desirable in a living hinge application. However, lower melt flow rate resins can be more difficult to mold properly.

Molecular Weight Distribution: A polypropylene resin with a broad molecular weight distribution results in superior integral hinge performance. Longer polymer chains cannot relax as easily as short chains.

Nucleation: Nucleation enhances hinge quality by accelerating the process of freezing the polypropylene orientation. However, it is important to note that if there is melt flow hesitation, nucleation will reduce the performance of the integral hinge. It is very important that the material, and molding parameters be balanced to produce an optimally functional integral hinge.

Polymer Type: Given their higher tensile strength, polypropylene homopolymers generally produce better integral hinges. Homopolymers are characterized by relatively high stiffness, even at elevated temperatures. However, they exhibit brittle behavior at temperatures below 5 °C (41 °F). Polypropylene random copolymers exhibit excellent transparency, and offer reduced stress whitening within the hinge. They generally exhibit cold temperature performance that is better than homopolymers. Polypropylene heterophasic copolymers (block copolymers or impact copolymers) are characterized by good impact properties down to temperatures below freezing.

Source:The Madison group
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#plastics #polymerscience #polypropylene #hinge #design #impact

Today's KNOWLEDGE Share: Why are Charcoal and Salt Added in the Earth Pit?

Today's KNOWLEDGE Share:

Why are Charcoal and Salt Added in the Earth Pit?

The combination of salt and charcoal is the perfect mixture which makes the ionic bonding for moisture in the earth pit. When the moisture increases in the soil, it increases the conductivity of the earth or ground conductor to the grounding rod or earth plat buried in the earth pit. That’s why the mixture of charcoal and salt is the best combination to put in the earth pit to maintain the low resistance.

An alternate layer of salt and charcoal is used to increase the effective area of the earth which leads to decrease the earth’s resistance.

As discussed above, the mixture of salt and charcoal as an alternate layer in the earth pit absorbs the moisture from the soil and surroundings. Additionally, the salt makes a perfect bonding with water, soil and charcoal. Therefore, the combination of charcoal and salt decreases the resistance and increases the conductivity of the earth pit. This way, the fault current can easily flow from the metallic body of the machine through the grounding conductor (earth continuity conductor) to the earthing lead and earth electrode (earth plat) buried in the earth pit.

The mixture of coal and powdered charcoal can maintain the moisture around the soil for a long time period. Hence, it reduces the resistance of earth pit and soil. This way, in case of fault, a less resistive path is available for fault current to flow to the ground. Thus, it provides proper protection to electrical machines as well as against the electric shock to a human body in contact with the metallic body of electrical appliances.

As the resistances may vary according to the different types of soil, thus it is important to check and test the conductivity of the soil before making an earth pit for grounding rods and earth electrodes (generally GI pipe or plate).

Keep in mind that the minimum and ideal resistance of the earthing and grounding system should be at least 1 Ω. If the resistance is more than 1-5+ ohms, you may increase the size of earthing lead and earth continuity conductor. Make sure to put water from time to time in the GI pipe connected to the earth pit which makes sure proper moisture around the earth plat. Hence, the earthing & grounding system for protection purposes works smoothly.

Source:Technical Engineering Portal (Linkedin)

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#charcoal #salt #earth #conductivity #conductor #electrode