Today's KNOWLEDGE Share :Warpage of Glass 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:CYANATE ESTER

Today's KNOWLEDGE Share

CYANATE ESTER:

Cyanate ester resins are a special class of polymeric materials whose molecules contain structural units of cyana(-CN) and carbonyl groups(-C00). Cyanate esters exhibit attractive physical, electrical, thermal, and processing properties. Blends with epoxy and bismaleimide are common.

Cyanate esters bear basically two cyanate groups (-OCN) attached to an aromatic ring. Also, aryl cyanate esters with additional allyl groups are known, e.g., 1-allyl-2-cyanatobenzene. Cyanates are formed by the reaction of phenols with cyanogen halides.

Cyanate ester resins are superior to epoxy resins, phenolic resins, and bismaleimide resins. They combine the advantages of epoxies, the fire resistance of phenolics, and the high-temperature performance of polyimides. Dicyanates of bisphenol derivatives are currently used in composites with established reinforcements such as carbon fiber, glass fiber, silica cloth, pitch-based graphite fibers.

Properties of Cyanate Ester Monomers:

Low Melt Viscosity

Good Solubility in Common Solvents

Compatible with Other Resins

Properties of Cured Resins:

High Tg

Low Thermal Expansion

Low Dielectric constant, Dissipation factor

Good Electrical Insulation

Applications:

Electronic Materials: Printed Wiring Boards for high frequency devices, Thermal Conductive Materials, etc.

Structural Materials: FRPs, Adhesives, etc.

Cyanate ester resins are currently used for many important applications such as high-temperature adhesives, and advanced composite matrices in the aerospace and automotive industry. A unique combination of properties such as high temperature stability and chemical resistance, low moisture uptake and low dielectric constant in the cured state, as well as low viscosity in the uncured state has led to their use in low-volume high-performance applications. The most common thermoplastic tougheners for epoxy systems are polysulfones (PSF), polyetherimides (PEI) or polyethersulfones (PES.

cyanate ester resins are used for high-temperature composites and adhesive applications. These systems can provide high glass transition temperatures (Tg = 170 - 350ºC), low water absorption and low dielectric properties. These products are typically used in aerospace and space applications, high-speed circuit boards, electronic chip adhesives and encapsulants, and syntactic foams.

Moisture resistance was improved by blending bisphenol A dicyanates with epoxy resins to reduce the amount of ester linkages in the resulting copolymer.

In order to enhance the moisture resistance of cyanate ester resins, modifiers containing silicon or fluorine moieties were introduced.

A high temperature resistant novolac cyanate ester was blended with polyethersulfone (PES) with different molecular weights using the solvent-free approach.

Key Players:

Huntsman

Lonza

Techia Corporation

Koniklijke TenCate

Cytec

Kuraray

Hexcel

Jiangdu Maida Group

Toray

Isola Group

Adeka

SGL Carbon

Gurit

Syensqo

Mitsubishi Gas Chemical

source:Mitsubishi

Suzuki Motor Corporation and Banas Dairy to invest over Rs 250 crore to establish four biogas plants in Gujarat

Suzuki Motor Corporation and Banas Dairy will invest over Rs 250 crore to establish four biogas plants in Gujarat. The project is aimed at making fuel for automobiles by refining methane from biogas. The biogas is created by fermenting cow dung, and the resulting liquid fertilizer will be used in agriculture, according to Banas Dairy Chairman Shankar Chaudhary, reported Ahmedabad Mirror.

An agreement between Maruti Suzuki and Banas Dairy will be inked for the same.The four biogas plants, set to begin operations in 2025 in Banaskantha district, will have a combined biogas production capacity of 500,000 liters. Each plant will also feature a biogas-filling station.

Suzuki’s commitment to achieving carbon neutrality through proactive biogas production initiatives will be highlighted during the visit of Suzuki President Toshihiro Suzuki to Banaskantha. He will tour the biogas plant, the cheese plant at Palanpur dairy, and the potato processing plant in Sanadar.

In December 2022, Suzuki signed a Memorandum of Understanding (MoU) with NDDB and Banas Dairy to launch a Biogas Demonstration Project. Additionally, Suzuki Research and Development in India (SRDI), NDDB, and Banas Dairy will sign an agreement for technical research in biogas technology, with plans to design a more efficient plant in Tharad.

Last year, Suzuki, NDDB, and Banas Dairy expressed interest in the Banaskantha biogas plants, aiming to reduce greenhouse gases and advance carbon neutrality through these proactive initiatives.

source:bioenergytimes.com

Liqcreate introduces new 3D printing resin “Rigid Pro” for demanding applications

Liqcreate, a manufacturer of 3D printing materials, has introduced a new technical 3D printing resin called Liqcreate Rigid Pro. This resin offers high chemical resistance, good temperature resistance and high strength and rigidity. These properties make it ideal for a wide range of applications in the engineering, automotive, electronics and oil and gas industries.

Liqcreate Rigid Pro is a rigid photopolymer resin that can be processed on most resin-based 3D printers. It is compatible with Digital Light Processing (DLP), Liquid Crystal Display (LCD) and laser-based 3D printing systems in the 385-420 nm range. This broad compatibility ranges from entry-level systems from Anycubic, Elegoo and Creality to professional systems such as Asiga, Nexa3D and UnionTech Martrix.

A key advantage of the Rigid Pro resin is its chemical resistance. Parts made with this resin can withstand a wide range of chemicals such as mild acids and bases. In addition, the material is also resistant to petrol and diesel, making it suitable for applications in the oil and gas and chemical industries. Customized chemical resistant parts can now be designed and printed within days at unprecedented costs.

For applications requiring high temperatures, Liqcreate Rigid Pro can achieve a heat resistance temperature (HDT-B) of 77°C through simple UV post-curing. With a Formlabs Formcure unit at elevated temperatures, this can be increased to 91°C and can even reach 109°C with an optional thermal post-curing step. This temperature resistance makes the resin suitable for automotive parts under the hood as well as medium temperature resistant castings and molded shells.

The Rigid Pro resin combines chemical and temperature resistance with a high flexural strength of 110 MPa. This opens up a wide range of applications in customer-specific machining and factory equipment. Parts exposed to static loads in the engineering industry can now be designed, 3D printed and post-processed within a day, without the need for a large stock of spare parts.

For OEM partners, the Rigid Pro resin can be renamed and optimized for different applications and 3D printers. In addition to its own resin range, Liqcreate offers a development service for customized formulas to meet specific properties. This enables customers to request polymers with precise properties that affect both the printing speed and the properties of the finished part.

Thanks to its own R&D facilities, Liqcreate is able to quickly scale up the production of customized resins. The company’s independence ensures a fast time to market and avoids delays that could arise from competition or conflicts of interest.

source:Liqcreate/3dprintr.com

Henkel further invests in its largest Indian manufacturing facility

Henkel Adhesives Technologies India Private Limited (Henkel India) announced the completion of Phase III of its manufacturing facility in Kurkumbh, near Pune, Maharashtra. The Kurkumbh site, which was launched in 2020, serves the growing demand of Indian industries for high-performance solutions in adhesives, sealants, and surface treatment products. The new Loctite plant, named after Henkel's renowned brand Loctite, was inaugurated by Mark Dorn, Executive Vice President, Henkel Adhesive Technologies, along with other Senior Management members of the company.

Henkel Adhesive Technologies entered the Indian market in 1996 and is a significant growth driver for this business today. Henkel has been expanding its presence in the country through consistent strategic investments to meet the rapid growth. Today, the company has a strong footprint in India and operates five manufacturing sites, two innovation centers, a customer experience center, a packaging academy, and an application center for the footwear industry.

The new Loctite plant in the Kurkumbh manufacturing site reflects Henkel's vision to drive growth in the Indian market. The plant will serve Indian businesses, further localize the product portfolio, and thus, reduce dependence on imports. It will also help address the supply-demand gap of high-performance adhesive solutions for the manufacturing, maintenance, repair and overhaul (MRO), and automotive components sectors. Henkel Adhesive Technologies is well-positioned to meet the demand arising in these fast-growing market sectors.

Speaking on the launch, Mark Dorn, Executive Vice President at Henkel Adhesive Technologies, said, “India has emerged as a focus market for Henkel globally. The new Loctite plant highlights our vision to emerge in the country as a self-reliant global market player with a strong local presence. With continued investments, efficient supply chains, and customer-focused solutions, Henkel is committed to driving growth in India and building ecosystems of innovative and sustainable solutions with our partners and customers.”

The Kurkumbh site also showcases Henkel's dedication to the local community as a responsible corporate citizen. It meets the highest standards of sustainability and is LEED Gold certified, a rare feature among chemical plants. In addition, Henkel aims to achieve carbon-neutrality in Kurkumbh for Scope 1 and 2 emissions by 2030. To support this ambition, the site has signed a green electrical energy Power Purchase Agreement and installed on-site solar panels.

source:Henkel

Today's KNOWLEDGE Share : New Thermoresponsive Adhesive for Pain-free Wound Dressings:

Today's KNOWLEDGE Share

New Thermoresponsive Adhesive for Pain-free Wound Dressings:

In a project funded by the Baden-Wuerttemberg Foundation, researchers at the University of Freiburg have developed an innovative adhesive polymer for wound dressings that adheres securely under temperature control but is easy to remove. This approach enables dressings to adhere firmly to the skin or wound site at body temperature without restricting the patient's freedom of movement.

However, when the dressing is cooled, such as with a cold pack, it can be removed very easily and without pain. Additionally, no adhesive residue remains on the healing tissue. The adhesive material's property of "switchable stickiness" is achieved through a crystallization process.

Adhesive Made of Copolymers and PVA Fatty Acid Esters:

The research team at the Institute of Macromolecular Chemistry at the University of Freiburg, led by prof. Dr. Rolf Mülhaupt and prof. Dr. Thorsten Steinberg, who supervised the project from a medical perspective at the Freiburg University Medical Centre, developed an adhesive consisting of copolymers and polyvinyl alcohol (PVA) fatty acid esters with crystallizable side chains and varying compositions.

The strategy is based on thermoresponsive polymers, which are solid at room temperature and molten at body temperature, exhibiting adhesion only in the molten state. Cooling induces crystallization of these side chains, resulting in a loss of adhesion to the skin. Crystallization causes physical cross-linking of the material, significantly inhibiting adhesion to the skin while increasing the material's cohesion. This allows the dressing to be removed in one piece without leaving any adhesive residue and without causing pain.

Simultaneously, the volume is reduced, decreasing the contact surface between the wound dressing and the skin, facilitating detachment.

Suitable for Burn and Infected Wounds:

In application, the material changes due to body heat and adheres accordingly. By applying a cold pack, the material crystallizes and no longer adheres to the skin. The material does not enter the wound. This wound dressing is particularly suitable for burns, allergic or sensitive skin, or infected wounds, as it prevents skin injuries or detachment. This type of wound dressing is also ideal for inpatient wound treatment or for large wounds, as it leaves no adhesive residue and exhibits excellent biocompatibility.

A patent application has been submitted for this invention (WO2023/ 134899A1). The Technologie-Lizenz-Büro (TLB) GmbH supports the scientists at the University of Freiburg and the Baden-Wuerttemberg Foundation in patenting and marketing the current development. TLB has been commissioned to commercialize this pioneering technology and offers manufacturers of wound care materials the options of licensing, purchasing the patent, or collaborating on further development.

Source: Universität Freiburg/adhesives.specialchem.com

Argonne-led Research Working Toward Reducing Electronic Waste With Biodegradable Luminescent Polymers

From your car’s navigation display to the screen you are reading this on, luminescent polymers a class of flexible materials that contain light-emitting molecules are used in a variety of today’s electronics. Luminescent polymers stand out for their light-emitting capability, coupled with their remarkable flexibility and stretchability, showcasing vast potential across diverse fields of application.

However, once these electronics reach their end use, they are discarded, piling up in landfills or buried underground. Recycling this electronic waste is complex, requiring expensive and energy-inefficient processes. Although there is an economic incentive to recycle the key semiconducting materials in this case, luminescent polymers there has been no method to achieve this due to the challenge of designing those materials at the molecular level.

Overcoming this challenge was the motivation behind the newest Nature Sustainability publication led by researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, along with collaborators at the University of Chicago, Purdue University and Yale University. The team developed a strategy to design luminescent polymers with high light-emitting efficiencies from the start that are both biodegradable and recyclable. They do so by incorporating a chemical called tert-butyl ester into the luminescent polymers, which can break down when exposed to heat or mild acid.

In short, this chemical enables the recycling of the material while maintaining high light-emitting functions.

The team then used a device to test the material’s external quantum efficiency, an indicator of light source performance. It scored an impressive 15.1% in electroluminescence, a tenfold increase from the existing degradable luminescent polymers.

At the end of life, this new polymer can be degraded under either mild acidic conditions (near the pH of stomach acid) or relatively low heat treatment (> 410 F). The resulting materials can be isolated and remade into new materials for future applications.

The team aims to make future electronics more sustainable (easier to degrade or recycle) and not just design for current function. They also want to expand the usability of these products into other fields.

Next steps for scaling the technology include moving it from the lab to electronics such as cell phones and computer screens with continued testing.

The team noted this is only a first step in the process, but with electronic waste, every step counts. They hope that more attention will be paid to designing electronics with sustainability in mind, especially since this depolymerization proof of concept was so successful.

source:Argonne National Laboratory/businesswire.com