Thursday, 21 October 2021

Guest Interview: Paolo Negri – Founder and Owner of Isotattica “Stop turning the knobs and apply hands-on rheology to troubleshoot and design your materials and equipment!”

Hello and welcome to this guest interview. Today I present to you Mr. Paolo Negri founder and owner of Isotattica. We have the chance to learn about analysis on polymer flow behaviour with innovative methods.

Enjoy the interview!


Tell us about yourself, your current role, and about Isotattica.

Thank you for having me on your blog. I am Paolo Negri founder and owner of Isotattica.

I have always worked in the fantastic world of polymers and I am driven by the passion of offering innovative service with multidisciplinary approach.

My Vision is to become a valuable reference for industrial rheology with innovative methods to be used with concrete problem-solving purpose.

With over 25 + years of transversal activities in the field of polymers, extrusion, rheometry, we provide technical support to solve problems that arise during processing phase of the materials, with strong focus on rheology as methodology and “tool” to elucidate and optimize processes and equipment.

What is the rheological investigation method and device you developed and what is the practical usage of it?

Rheology is concerned with measuring the stress in a material and relating it to its deformation in the molten flow of the material.

Rheology is still little known in the industrial field because it is considered complex, of impractical implementation and does not bring practical results, vice versa I want to propose a different way of utilization of it: if findings are expressed in an understandable reading and applied in a pragmatic and concrete way to industrial processes, rheology becomes a valid approach to understand and resolve critical issues.

Understanding the flow properties of polymers through tests directly on extrusion-connected equipment can help optimize products and process conditions, thus saving costs and minimizing potential waste.

My motto is: Stop turning the knobs and apply hands-on rheology to troubleshoot and design your materials and equipment!

Isotattica offers analysis on flow behaviour with innovative methods: flow visualization and rheometric measurement through flow-induce birefringence and elongational experiments made with a filament stretching apparatus.

The first approach is innovative (the optical cell is patent pending) and allows flow visualization and mapping of stresses and deformation inside the geometry of flow channels. Thanks to the so called “optical rule” is it possible to sequence and calculate stresses and finally to determine viscosity in the melt stream where elongational specifically takes place.

The second approach, filament-stretching-method, is mainly used as complementary test and allows assessment of the melt quality in extensional experiments.

I invite readers to learn more on my website www.isotattica.com.

What are some potential applications?

The proposed methods of analysis are very sensitive: it is possible to replicate industrial process condition and capture the details that explain the difference in extrudability, for example due to the smallest of batch fluctuation;

In addition, it is possible to understand the contribution of elongational deformation in “complex flow” and correlate structure-property-processing-performance.

Die designers benefit from this because they can finally size the channels paths and tooling’s based on the specific and well understood flow responses of the materials and not based on generic data.

Where can the readers find out more about you and the services of Isotattica?

Whatever you would like to know about Isotattica including practical examples of utilization of these analysis, you can visit our website www.isotattica.com or simply mail or call me asking to provide specific details and offers.

With the pandemic continuing, we are more enhancing on in-direct communication via video conferences.

Who do you turn to?

We provide concrete and pragmatic support:

- To those who need to design new materials / compounds and perform rheometric characterizations for mapping and quantifying flow response, with emphasis in the extensional field in the various channel’s geometries or in downstream operation like blowing, cast film, profile extrusions, strand palettization, injection molding and many others

- To those who need to design and manufacture process equipment and layouts (co-extrusion heads / dies, extruders, downstream equipment) for specific industrial applications where knowledge of the shear characteristics but above all in elongation are vital.

- Who must study the extrusion process and its efficiency based on the rheological response of the materials and their stability when changing extrusion settings.

- To producers and converter of materials, or to deepen the intimate rheological aspects that cannot be captured with conventional approaches and that can make the difference.

- To those who need material consultation, for proper material selection, design review, feasibility study.

- To those who want to acquire mastery in dealing with and solving problems and improve business by distinguishing themselves from competitors.

That was the guest interview with Paolo Negri from Isotattica – thank you Paolo for the interesting insights into the polymer rheology world!

Greetings and #findoutaboutplastics

Herwig Juster

#rheology #guestinterview #Isotattica

Interested to talk with me about your plastic selection and part design needs - here you can contact me 

Interested in my monthly blog posts – then subscribe here and receive my high performance polymers knowledge matrix.
New to my Find Out About Plastics Blog – check out the start here section
You can support me here on  PayPalMe
Polymer Material Selection (PoMS) for Electric Vehicles (xEVs) - check out my new online course


Monday, 11 October 2021

Bio-Based Polyamides – Part 2: Short and Long Chain Aliphatic Polyamides (PA 6, PA 11, PA 6.10, PA 10.10)

Hello and welcome back to our bio-based polyamide blog series. In part 1 we discussed the bio-based PA 5.6 and today in part 2 we discuss bio-based homopolyamides (short and long chain) as well as long chain copolyamides (polyalkylene sebacamides).

Homopolyamides from Biomass Derived Monomers

There are two commercially feasible ways in making biomass based Polyamide 6 (Figure 1): the first route is over sugar and the second route uses starch as a starting point. In the second route an additional processing step is needed (hydrolysis of starch to obtain Glucose). For obtaining a long chain homopolyamide (PA 11), five processing steps are involved and 93% more biomass is needed to obtain 1 metric ton of Polyamide. AS a starting point for Bio-PA 11, caster beans are used.

Figure 1: Routes for making Bio-PA6 and Bio-PA 11


Copolyamides from Biomass Derived Monomers

For obtaining a long chain biomass based copolyamide we need a diamine which reacts with a diacid and either both (fully bio-based) or just one (partially bio-based) is derived from biomass. In Figure 2, the reaction routes of Bio-PA 6.10 and Bio-PA 10.10 are shown.

Figure 2: Routes for making Bio-PA 6.10 and Bio-PA 10.10


Selected properties of bio-based polyamides

In Table 1, typical properties of petroleum-based and bio-based polyamides are shown. The functional amide group which facilitates an internal hydrogen bond between the polymer chains, leads to properties such as hardness, good impact strength and excellent abrasion resistance. Comparing short chain to long chain aliphatic polyamides, the short chain outperforms the long chain in terms of thermal and mechanical properties. However, the long chain aliphatic polyamides have a higher chemical resistance as well as hydrolysis resistance together with low water uptake. Bio-based Polyamides cover the short chain and long chain spectra and depending on the application case, they can outperform or underperform petrol-based Polyamides. The properties shown in Table 1 are the base polymer properties and in most cases the base polymer will be modified with glass fibers and additives. This in turn will make direct comparisons more difficult and more data must be considered in the polymer material selectionprocess (long term data, cyclic data, and chemical data).  

Table 1: Selected properties of petrol- and bio-based Polyamides

Processing and Applications

Injection moulding polyamides represents around 76% of the total polyamide consumption and the automotive and truck market is here in the lead in terms of annual consumption. Other important markets are consumer articles, electrical and electronic parts and appliances parts. Extrusion represents 23% of the total polyamide consumption and covers applications in the field of wire and cable, tubing and piping, and non textile filaments. The remaining 1 % represents powder coating applications.

Bio-based Polyamides start to capture applications in the automotive field, especially for Electric Vehicles. However, due to the current price level and capacities, Automotive will not be the dominating applications field. Long chain bio-based Polyamides offer different properties compared to the more price sensitive short chain Polyamides. Blending and co-polycondensation with petrol based Polyamides will allow to reach the ideal price-to-performance ratio faster. Ongoing regulations to reach certain CO2 levels and Global Warming Potentials (GWP) allows bio-based Polyamides to faster capture applications in different industry sectors. Also, customer demand for such solutions is increasing as well as the regulations.

Thank you for reading and #findoutaboutplastics

Greetings

Herwig Juster

#materialselection #polymerengineering #biobased #biopolyamides

Interested to talk with me about your plastic selection and part design needs - here you can contact me 

Interested in my monthly blog posts – then subscribe here and receive my high performance polymers knowledge matrix.
New to my Find Out About Plastics Blog – check out the start here section
You can support me here on  PayPalMe
Polymer Material Selection (PoMS) for Electric Vehicles (xEVs) - check out my new online course


Literature:

[1] https://polymerdatabase.com/Polymer%20Brands/Biopolyamides.html

[2] https://matmatch.com/learn/material/biopolymers?utm_content=175746192&utm_medium=social&utm_source=linkedin&hss_channel=lcp-21389968

[3] https://www.ifbb-hannover.de/files/IfBB/downloads/faltblaetter_broschueren/Biopolymers-Facts-Statistics-2018.pdf

[4] Bio-Based Plastics Materials and Applications, S. Kabasci;

Tuesday, 28 September 2021

Bio-Based Polyamides – Part 1: PA 5.6 and 5T (Chemical Structure, Production, Properties, Applications, Value Proposition)

Hello and welcome to this three part series on bio-based polyamides. Since biopolymers are among the fastest growing segment in the polymer industry it is worth having a closer look at selected new polymers, such as the PA 5.6. In the first part we will discuss some definitions and then turn the focus towards Polyamide 5.6 and 5T. In part two we have a look at bio-based PA 6.6 and in the third part onto bio-based high performance polyamides.

Definitions and some basics

In this training video I review the chemistry of Polyamide 6 and Polyamide 6.6, discuss the properties and applications of Polyamides and look at their global demand and producers.

In general, Polyamides are semi-crystalline condensation polymers with repeating amide (–CO–NH–) links in their backbone. The number after the prefix ‘PA’ results from the number of carbon atoms between the amide groups. Furthermore, there are Monadic (AB) and Dyadic (AABB) Polyamides. AB-Polyamides have a single repeating lactam with an amine reactive group and as a ‘B’ component a carboxylic acid group. AABB-Polyamides are created by the reaction of diamine and a diacid. For them, the first number after the prefix ‘PA’ is the diamine and the second number describes the diacid. Now back to our bio-based Polyamides

Chemical structure and production of bio-based PA 5.6

Pentamethylene diamine, which is needed for PA 5.6, can be made from biomass or sugar. This is enabled by using microorganisms and in 2013 the company Cathay Industrial Biotech was able to increase the efficiency of amino acid decarboxylase by 100 times during the biological fermentation processes. As an enabler, a gene engineering technique was applied. This can be considered as the breakthrough for industrial up-scale of bio-sourced pentamethylene diamine (commercial name: C-BIO N5). Condensation reaction of the green diamine with a diacid (petrol based or bio-sourced) will lead to a full or partially bio-sourced Polyamide 5.6 (commercial name: Terryl™), depending if the diacid is bio-based too. Cathay claims that 8% less diamine is needed with C-Bio N5.

Cathay and Toray too hold patents on Polyamide PA5T. In general, the melt temperature of 5T is lower compared to PA6T and glass transition temperature of 5T is 141°C and therefore slightly higher (Tg 6T = 138 °C) which results in an improved thermal stability. Due to the high amide group concentration of PA 5.6 and PA5T, water absorption is higher compared to PA6T and PA 6.6.

Properties of PA 5.6 compared to PA 6.6 and PA 6

In the table below major thermal and mechanical properties of PA 5.6, in comparison to PA 6 and PA 6.6 are shown. The comparison indicates that PA 5.6 is more similar to PA 6.6 than to PA6.

Table 1: Property Comparison of Petrol-Based vs. Bio-Based Polyamides

Processing and applications

Processing of bio-based PA 5.6 can be done via the melt fiber spinning route for yarns and textiles as well as injection moulding for engineering parts. Since some internal H and O sites are free (compared to PA 6.6 where all internal H and O sites are bound), an easier dyeing is achieved. Furthermore, the higher moisture absorbance increased the comfort of wearing. Injection moulding compounds reinforced with glass fiber, enter different industries such as automotive, electrical, and industrial.

Environment, Health, Safety and Value Proposition

The bio organism fermentation approach described in the first section represents a safer route to produce monomers and polymers due to lower temperature, low pressure and much less toxic raw materials as well as by-products. This in turn makes the whole process more environmentally friendly, reduces the carbon footprint and also energy requirements. The value proposition of bio-based plastics in general is that by switching the monomer sourcing base from petrol to bio-based plant feedstock an  material with intrinsically zero carbon footprint is obtained. The obtained polymers are not necessarily biodegradable and the optimal end-of-life option (for example circular economy approach) needs to be further developed. 

Also, PA5X (X=6, 10, 12, 13, 16, 18) and PA56T are all already commercially available for global market applications which allows them to be the tomorrow's choice to cover sustainable, renewable and environmental demands.

In this post I discuss the difference between bio-based content vs. bio-based carbon content and in this post helpful standards for composting of biodegradable polymers. In the second part we discuss bio-based Polyamide 6.6 – stay tuned!

Thank you for reading and #findoutaboutplastics

Greetings

Herwig

#materialselection #polymerengineering #biobased

Interested to talk with me about your plastic selection and part design needs - here you can contact me 

Interested in my monthly blog posts – then subscribe here and receive my high performance polymers knowledge matrix.
New to my Find Out About Plastics Blog – check out the start here section
You can support me here on  PayPalMe
Polymer Material Selection (PoMS) for Electric Vehicles (xEVs) - check out my new online course


Literature:

[1] Bio-Based Plastics Materials and Applications, S. Kabasci;

[2] TERRYL™ bio-based nylon, P. Caswell, Cathay Industrial Biotech

[3] Progress in semi crystalline heat-resistant polyamides, C. Zhang

[4] https://matmatch.com/learn/material/biopolymers?utm_content=175746192&utm_medium=social&utm_source=linkedin&hss_channel=lcp-21389968

[5] https://matmatch.com/learn/property/difference-between-biodegradable-compostable-and-degradable?utm_content=176494659&utm_medium=social&utm_source=linkedin&hss_channel=lcp-21389968

Monday, 20 September 2021

Design Properties for Engineers: UL RTI vs HDT of Commodity, Engineering and High Performance Polymers

In this blog post, we compare the long-term thermal properties (based on UL RTI 746B) to the short-term properties (based on the Heat Deflection Temperature, HDT @ 1.8 MPa).

The figure below shows the comparison of the long-term and short-term thermal data. This allows designers to immediately assess the suitability of a selected polymer in terms of continuous heat exposure as well as short-term heat impact. Furthermore, alternative polymers can be selected too.

UL RTI vs. HDT (1.8 MPa):Long-Term vs. Short-Term Thermal Properties of Thermoplastics


I made a YT video which shades light into this topic in more detail:



Thank you for reading and #findoutaboutplastics

Greetings

Herwig Juster

#materialselection #polymerengineering #plasticsdesign

Interested to talk with me about your plastic selection and part design needs - here you can contact me 

Interested in my monthly blog posts – then subscribe here and receive my high performance polymers knowledge matrix.
New to my Find Out About Plastics Blog – check out the start here section
Polymer Material Selection (PoMS) for Electric Vehicles (xEVs) - check out my new online course


Literature:

[1] UL Prospector – 746B

Monday, 13 September 2021

Rule of Thumb for Plastics Injection Moulding: Weld Line vs Meld Line

 In this rule of thumb post, we discuss the difference between a weld line and a meld line in polymer injection moulding as well as how we can apply effective troubleshooting.

In short: the angle at which the converging polymer flow front meets in the tool again determines the difference between weld line and meld line.

A weld line is formed if the angle is less than 135°.  A meld line is formed if the angle is greater than 135° and the polymer molecules are more uniform compared to the orientation formed after a weld line. This is demonstrated in the picture below.

It is important to understand the flow fronts and the flow angle for achieving proper weld lines. Such an understanding allows the use of multiple submarine gates rather than fan gates to be used. Prediction of weld lines prior to the tool being cut allows the optimization of the part design and gate location which in turn reduces tool development time. Consideration of material, filler and pigmentation is important and this is why discussion with the technical team at your material supplier at the early stages are useful.

Rule of Thumb: Weld Line vs Meld Line


Troubleshooting of weld and meld lines

Weld and meld lines can cause a decrease in mechanical properties and are often clearly visible on the surface. An effective way of troubleshooting them is to move them in a non-functional / non-visible area. This can be achieved by changing the gate position or part thickness. Furthermore the allover quality can be improved by increasing the melt and mould temperature. This facilitates a better interfusion of the flow fronts. Also injection speed can help as well as an optimization of the runner system design.



Thank you for reading and #findoutaoutplastics

Greetings,

Herwig Juster

Interested to talk with me about your plastic selection and part design needs - here you can contact me 

Interested in my monthly blog posts – then subscribe here and receive my high performance polymers knowledge matrix.
New to my Find Out About Plastics Blog – check out the start here section
Polymer Material Selection (PoMS) for Electric Vehicles (xEVs) - check out my new online course


Literature:

[1] https://knowledge.autodesk.com/support/moldflow-insight/learn-explore/caas/CloudHelp/cloudhelp/2017/ENU/MoldflowInsight/files/GUID-099634AE-DB7A-41BA-B70C-5A23FB013B06-htm.html

Tuesday, 7 September 2021

Design Properties for Engineers – Comparison Property Data of Polyphthalamides (PPAs)

 Hello and welcome to a new post. In this post I provide you engineering comparison data of the 5 most used PPA base polymers and their glass-fiber reinforced compounds. Semi-aromatic polyamides are used when the aliphatic counterparts reach their limits due to high temperature and/or mechanical loads.

The five base polymers of PPA are:

-PA 6T/6.6

-PA 6T/6I/6.6

-PA 6T/6I

-PA 6T/DT

-PA 10T/X

The data are shown in property vs. density plots and we are comparing the semi-aromatic polyamides to aliphatic polymers.  

Background

Semi-aromatic polyamides have an amide linkage together with an aromatic ring. The aromatic content is most of times derived from 2-methylpentanediamine (DT), terephthalic acid (TPA) and/or isophthalic acid (IPA). In general, the aromatic structure helps to increase the glass transition temperature, which in turn increases the thermal and chemical resistance. Furthermore, reduction in water uptake is achieved. More details can be found in this post.

The following properties are presented in the below infographic (PPA reinforced with 50% glass fibers):

-Glass transition temperature

-Melt temperature

-Tensile strength (dry as moulded; conditioned)

-Tensile modulus (dry as moulded; conditioned)

-Heat Deflection Temperature (HDT; 1.8 MPa)

-Izod notched impact strength




Design Properties for Engineers – Comparison Property Data of Polyphthalamides (PPAs)

Thanks for reading and #findoutaboutplastics

Greetings,

Herwig

Interested to talk with me about your plastic selection and part design needs - here you can contact me 

Interested in my monthly blog posts – then subscribe here and receive my high performance polymers knowledge matrix.
New to my Find Out About Plastics Blog – check out the start here section
Polymer Material Selection (PoMS) for Electric Vehicles (xEVs) - check out my new online course


Literature:

[1] D. Kemmish: Practical Guide to High Performance Engineering Plastics, Smithers

[2] D. Glasscock: High Performance Polyamides Fulfill Demanding Requirements for Automotive Thermal Management Components, DuPont Engineering Polymers

[3] Eurotec: Tecomid High Performance Compounds

[4] Saechtling Kunststoff Taschenbuch, Hanser



Wednesday, 25 August 2021

Polymer Material Selection: Pre-Selection of Thermoplastics

Hello and welcome to this post. Today I will discuss with you a practical approach on how to pre-select thermoplastics for your application.

In a past post I touched on some rules of thumb for making an educated guess on plastics material selection and in this post we will add another approach into our plastic selection toolbox.

Thermoplastics can be divided into amorphous and semi-crystalline morphology. Amorphous polymers are transparent or translucent, whereas semi-crystalline polymers are opaque. If you need a transparent part, then selecting an amorphous polymer is the path forward. Flexible polymers with a Young’s Modulus of < 1500 MPa are always semi-crystalline. Amorphous polymers can only be used below their glass transition temperature (Tg) and therefore have always a stiff behavior up to their Tg. If you need flexible and transparent polymers, amorphous Polyamide can be an option when working with additives (clarifiers) helping to make a semi-crystalline transparent. 

Maximum use temperature and Young’s modulus

In the table below are amorphous and semi-crystalline resins shown, together with the Young’s modulus and maximum use temperature as selection criteria. All the values are for orientation and further investigation for proper material selection needs to be done (for example, mechanical properties over different temperatures). Detailed data can be found in the Technical Data Sheets (TDS) of material suppliers or in material databases. Also on my blog, I have several engineering data in particular for high performance polymers listed.


Polymer material selection: pre-selection of thermoplastics by using maximum use temperature and Young's modulus


Thanks for reading and #findoutaboutplastics,

Herwig

#polymerMaterialSelection #herwigjuster

Interested to talk with me about your plastic selection and part design needs - here you can contact me 

Interested in my monthly blog posts – then subscribe here and receive my high performance polymers knowledge matrix.
New to my Find Out About Plastics Blog – check out the start here section
Polymer Material Selection (PoMS) for Electric Vehicles (xEVs) - check out my new online course


Literature:

[1] M. Bonnet: Kunststofftechnik: Grundlagen, Verarbeitung, Werkstoffauswahl und Fallbeispiele