Today's KNOWLEDGE share:PET Vs PETG: THE MAIN DIFFERENCES

Today's KNOWLEDGE share:

PET Vs PETG: THE MAIN DIFFERENCES

A basic formula for making polyesters, like PET and PETG, is the combination of acid monomers plus glycol monomers. In the case of PET, the acid is usually DMT (dimethyl terephthalate) and the glycol is ethylene glycol. These two monomers are the building blocks of the final long-chain polymer: polyethylene  terephthalate.

For creating PETG, the same monomers are used, except some ethylene glycol (30-60%) is substituted with a different glycol monomer, CHDM (cyclohexanedimethanol). So it’s not that PETG has significantly more or less glycol than PET, it just has a different type of glycol. Therefore, the -G in PETG represents the chemical modification of the typical PET structure with CHDM glycol units, or “glycol-modified” for short.

The key impact of this glycol modification from a physical standpoint is that semi-crystalline PET gets transformed into amorphous PETG. Let’s quickly review what crystallinity has to do with polymers and why it's relevant to 3D printing.

In a few words, amorphous polymers have all their chains arranged randomly, much like a bowl of spaghetti. Semi-crystalline polymers contain regions of crystallinity where chains are highly-ordered and densely packed. This has an enormous impact on material properties.

Semi-crystalline materials are generally more rigid compared to a totally amorphous counterpart, as crystalline regions can function as reinforcement. This holds true for semi-crystalline PET and amorphous PETG.

While cooling, semi-crystalline materials are prone to warping caused by changes in density brought on by the formation of crystalline regions. This means amorphous PETG is much more manageable for 3D printing. Semi-crystalline PET, on the other hand, requires stricter printing and ambient temperatures to prevent distortions.

PET also has a slightly higher working temperature compared to PETG due to its crystalline nature. While this may make it more difficult to print with, PET will hold up better in applications that require some thermal resistance.

You may also notice visual differences between the two materials. The purely random nature of the polymer chains in PETG creates glossy or even transparent filaments. PET, as a mixture of crystalline and non-crystalline regions, will have some haziness.

Crystalline structures, like those of PET, don’t play well with extrusion. Crystallization is difficult to control and can begin as soon as the plastic is just a bit too cool. Manufacturers often facilitate extrusion using additives that hinder crystallization.

On the other hand, glycol modification of PET renders it an amorphous material that can easily be modeled via extrusion, injection molding, and other thermo-forming processes. This is the key to the success of PETG.

Source:all3dp

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#3dprinting #plastics #pet #petg #molding

Today's KNOWLEDGE Share : 3D printing in medical applications

 Today's KNOWLEDGE Share

🧠 Can we already 3D print human bone – and can it ever match the real thing?

3D printing has opened incredible doors in medicine:

🖨️ Custom implants,

🧬 Patient-specific guides,

🧫 Even bioprinted tissues.

And now we ask: Can we 3D print bone?

The idea sounds magical design a defect-specific structure, print it, implant it, and let it heal.

But as exciting as it is, we need to ask:

👉 Can a printed bone truly replace what biology has perfected over millions of years?

The answer isn’t simple — because real bone isn’t just a shape.

It’s a living, dynamic tissue made of:

• Haversian canals

• Cortical and trabecular architecture

• Biomechanical gradients

🦴 Natural bone is never just a block of material.

3D printing brings us closer in terms of geometry — but structure, remodeling, and biological function remain major challenges.

💬 Here’s the issue:

How do we make printed bone as hard, elastic, and biologically responsive as real bone?

What “glue” holds the printed structure together — and how do we replicate true integration?

They may look similar — but printed models lack the internal complexity and adaptability of living bone.

💡 That’s why biological implants like the Surgebright are so exciting:

🦈 Made from 100% human cortical bone,

🧬 Fully remodelable, revascularizable, and naturally integrated.

📉 No metal, no removal surgeries, no compromise in healing.

Shark Screw® doesn’t try to imitate bone — It is bone.

With over 8,000 successful cases and growing international use, it shows what’s possible when we work with biology, not against it.

So what do you think?

➡️ Will 3D printing ever catch up?

Or are allografts and natural scaffolds already the better way forward in many cases?

👇 Let’s discuss.

source : Thomas Pastl

Dow introduces high-temperature silicone gel to boost efficiency in EV power electronics

Dow has launched DOWSIL EG-4175 #SiliconeGel, a protective material designed to support next-generation insulated gate bipolar transistor (IGBT) modules operating at higher voltages. This new gel withstands temperatures up to 180°C and is targeted at power electronics in #electricvehiclebatteries and main inverters, as well as inverters used in photovoltaic panels and wind turbines.

According to Dow, #DOWSILEG4175 Silicone Gel is formulated to handle the elevated temperatures found in seventh-generation IGBT modules as battery voltages in EVs increase from 400 V to 800 V to improve inverter performance and enable faster charging. The gel is engineered for enhanced dielectric strength and thermal resistance, supporting higher power densities and enabling the handling of greater electrical loads.

The gel features self-healing properties to repair small cracks, vibration absorption, and self-priming adhesion to protect delicate electronics. It cures at room temperature for energy-efficient manufacturing, but the process can be accelerated with heat to reduce production cycle times. Dow also notes that this gel exhibits low levels of silicone oil bleed and adheres to substrates without the need for a primer.

The product builds on Dow’s existing portfolio of silicone-based dielectric gels that offer electrical insulation, encapsulation, mechanical stress relief, and environmental protection. DOWSIL EG-4175 Silicone Gel is complemented by DOWSIL EA-7158 #Adhesive—also formulated for IGBT modules—which offers one-part, high-strength performance, rapid heat curing and translucent color for easier inspection.

#Dow is upgrading our IGBT materials portfolio to address the emerging trend toward achieving higher power densities,” said Cathy Chu, global strategic marketing director, Consumer and Electronics, Dow. “With its higher-temperature resistance compared to incumbent materials, this new silicone gel will enable our customers to design and manufacture higher-density IGBT modules with greater power system efficiency.”

Both silicone-based products for #IGBTmodules are now available globally, according to Dow.

source: Dow /Chargedevs

Today's KNOWLEDGE Share : Google Pixel 10 Series Smartphones Employ TORAYCON™ Recycled PBT Resin

Today's KNOWLEDGE Share

Google Pixel 10 Series Smartphones Employ TORAYCON™ Recycled PBT Resin

Toray Industries, Inc., announced today that new #GooglePixel10 smartphones incorporate #TORAYCON ™, a chemically #recycledPBT resin. Google LLC launched this series on August 21.

Google lauded this #engineeringplastic for its excellent mechanical properties and colorability that is equivalent to that of virgin materials.

Toray provides the following diverse recycled resin and related offerings (see below) for customers looking to increase their recycled content.

Resin type : ABS, PA6, PA66, PBT, and PPS

Raw material : Post-industrial and post-consumer recycled materials

Recycling method : Mechanical and chemical recycling techniques

One goal of the Toray Group Sustainability Vision for 2050 is to contribute to a world in which resources are sustainably managed.

The company will keep catering to customer demand for recycled resin in keeping with its commitment to delivering new value and contributing to social progress.

source : Toray

What is Zinc Oxide?

What is Zinc Oxide?

Zinc Oxide (ZnO) is more than just a chemical compound—it's a versatile performance additive crucial to a wide range of industries. Produced by companies like Zochem LLC, the largest dedicated producer in North America, zinc oxide is manufactured using the French Process, a method that ensures a final product with a purity of 99.9% or higher.

This fine, nodular-shaped powder or pelletized substance is a critical component in many applications you encounter daily:

Tire & Rubber: It acts as a key activator for the vulcanization process, making rubber products more durable.

Plastics: It serves as a UV and heat stabilizer, protecting plastics from degradation and extending their lifespan.

Paint & Coatings: It provides UV protection, corrosion resistance, and acts as a biocidal agent to prevent mold and mildew growth.

Pharmaceuticals: USP-grade zinc oxide is used in a variety of medical and health-related products, adhering to strict regulatory standards.

Zochem's commitment to sustainability is evident in their focus on recycling scrap zinc to produce high-quality zinc oxide. This not only emphasizes the broad utility of the material but also ensures "certainty of quality, consistency, and supply" while minimizing environmental impact. By promoting a circular economy, Zochem contributes to sustainable practices in the industry. For more information, here are some recommended resources:

source : #ZochemLLC

#zincoxide

Today's KNOWLEDGE Share : 𝗠𝗮𝘁𝗲𝗿𝗶𝗮𝗹𝘀 𝘁𝗵𝗮𝘁 𝗠𝗮𝘁𝘁𝗲𝗿 — 𝗣𝗣𝗦 (𝗣𝗼𝗹𝘆𝗽𝗵𝗲𝗻𝘆𝗹𝗲𝗻𝗲 𝗦𝘂𝗹𝗳𝗶𝗱𝗲𝘀)

Today's KNOWLEDGE Share

𝗠𝗮𝘁𝗲𝗿𝗶𝗮𝗹𝘀 𝘁𝗵𝗮𝘁 𝗠𝗮𝘁𝘁𝗲𝗿 — 𝗣𝗣𝗦 (𝗣𝗼𝗹𝘆𝗽𝗵𝗲𝗻𝘆𝗹𝗲𝗻𝗲 𝗦𝘂𝗹𝗳𝗶𝗱𝗲𝘀)

𝗦𝘁𝗿𝘂𝗰𝘁𝘂𝗿𝗲 | 𝗣𝗿𝗼𝗽𝗲𝗿𝘁𝗶𝗲𝘀 | 𝗔𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻 | 𝗗𝗼𝘄𝗻𝘀𝗶𝗱𝗲 | 𝗦𝗽𝗼𝘁𝗹𝗶𝗴𝗵𝘁: Teijin Carbon

#𝗣𝗣𝗦 is a semi-crystalline, high-performance 𝗲𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝗶𝗻𝗴 𝘁𝗵𝗲𝗿𝗺𝗼𝗽𝗹𝗮𝘀𝘁𝗶𝗰 consisting of a 𝗹𝗶𝗻𝗲𝗮𝗿 𝗮𝗿𝗼𝗺𝗮𝘁𝗶𝗰 𝗯𝗮𝗰𝗸𝗯𝗼𝗻𝗲 𝘄𝗶𝘁𝗵 𝗮𝗹𝘁𝗲𝗿𝗻𝗮𝘁𝗶𝗻𝗴 𝗯𝗲𝗻𝘇𝗲𝗻𝗲 𝗮𝗻𝗱 𝘀𝘂𝗹𝗳𝗶𝗱𝗲 𝗹𝗶𝗻𝗸𝗮𝗴𝗲𝘀.

This structure provides 𝗲𝘅𝗰𝗲𝗽𝘁𝗶𝗼𝗻𝗮𝗹 𝗰𝗵𝗲𝗺𝗶𝗰𝗮𝗹 𝗿𝗲𝘀𝗶𝘀𝘁𝗮𝗻𝗰𝗲, 𝗳𝗹𝗮𝗺𝗲 𝗿𝗲𝘁𝗮𝗿𝗱𝗮𝗻𝗰𝘆, 𝗮𝗻𝗱 𝗱𝗶𝗺𝗲𝗻𝘀𝗶𝗼𝗻𝗮𝗹 𝘀𝘁𝗮𝗯𝗶𝗹𝗶𝘁𝘆, even in aggressive thermal and chemical environments. Its tightly packed aromatic chains and high crystallinity result in 𝗵𝗶𝗴𝗵 𝘀𝘁𝗶𝗳𝗳𝗻𝗲𝘀𝘀 𝗮𝗻𝗱 𝗲𝘅𝗰𝗲𝗹𝗹𝗲𝗻𝘁 𝗲𝗹𝗲𝗰𝘁𝗿𝗶𝗰𝗮𝗹 𝗶𝗻𝘀𝘂𝗹𝗮𝘁𝗶𝗼𝗻 𝗽𝗿𝗼𝗽𝗲𝗿𝘁𝗶𝗲𝘀, with minimal creep under load.

PPS is commonly used in 𝗽𝘂𝗺𝗽 𝗵𝗼𝘂𝘀𝗶𝗻𝗴𝘀, 𝗲𝗹𝗲𝗰𝘁𝗿𝗶𝗰𝗮𝗹 𝗰𝗼𝗻𝗻𝗲𝗰𝘁𝗼𝗿𝘀, 𝗣𝗖𝗕 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁𝘀, 𝗮𝗻𝗱 𝗳𝗹𝘂𝗶𝗱 𝗵𝗮𝗻𝗱𝗹𝗶𝗻𝗴 𝘀𝘆𝘀𝘁𝗲𝗺𝘀, where chemical resistance and thermal stability are critical, often up to 200 °C continuous use. Pictured below are 𝘁𝗶𝗲 𝗿𝗼𝗱𝘀 made from PPS UD tape and injection molded materials.

Its primary weakness is 𝗯𝗿𝗶𝘁𝘁𝗹𝗲𝗻𝗲𝘀𝘀, especially in unfilled or unmodified grades, which limits its impact strength without fiber reinforcement or toughening agents.

𝗣𝗣𝗦 𝗨𝗗-𝗧𝗮𝗽𝗲𝘀 reinforced with carbon fibers can be procured from 𝗧𝗲𝗶𝗷𝗶𝗻 𝗖𝗮𝗿𝗯𝗼𝗻 𝗘𝘂𝗿𝗼𝗽𝗲. Teijin Carbon has their 𝘁𝗮𝗽𝗲 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝗶𝗼𝗻 𝗹𝗼𝗰𝗮𝘁𝗲𝗱 𝗶𝗻 𝗛𝗲𝗶𝗻𝘀𝗯𝗲𝗿𝗴, 𝗚𝗲𝗿𝗺𝗮𝗻𝘆 and is subsidiary of Teijin Limited. Teijin Limited is headquartered in Tokyo, Japan, and is one of the world’s leading suppliers of 𝗵𝗶𝗴𝗵-𝗽𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲 𝗳𝗶𝗯𝗲𝗿𝘀, including Tenax® carbon fiber, which is widely used in aerospace, automotive, and industrial composite applications.

The benefits of Tenax™ ThermoPlastic UniDirectional

High-performance mechanical properties

Low flammability, smoke and toxicity

Excellent resistance to chemicals and solvents

Room temperature storage and shipping

Compliant with health, safety and environment requirements

Recyclable

Out of autoclave consolidation (press forming, vacuum bagging)

Short cycle time

Thermoformable

Automated processes (automated tape laying, winding for tubular parts and pressure vessels)

Thermoplastic joining technologies

source : Alformet /Teijin

Modelling the direct reduction of iron is challenging

 #Modelling the direct reduction of #iron is challenging – it involves complex, multi-scale processes like phase transformations and gas transport in porous pellets. Conventional models often rely on fitting to experimental conversion data, which can leave critical mechanisms underexplored.

Ömer Kerim Büyükuslu and his colleagues developed a thermodynamically grounded pellet-scale model for H₂/CO atmospheres that captures key reaction mechanisms with fewer fitting parameters, while strictly enforcing thermodynamic limits. By adding spatially resolved microstructural data into model calibration, they reveal how reduction progresses inside the pellet.

This approach provides a tool for understanding and optimising hydrogen-based ironmaking – a key step towards greener #steel production.

#openaccess paper: https://lnkd.in/d4D89bvk

source : Max Planck Institute for Sustainable saterials