Monday 12 February 2024

Total carbon footprint (TCF) of consumers: what role do plastics play?

Hello and welcome to this new blog post. Today we investigate the question of what impact plastic products have on our total carbon footprint. When one is confronted with the question of "do i use too much plastic products and harm the environment?", the short answer is no and here is why: 

Let us start with the following question: 

How much plastic do we use?

The answer was well researched by independent scientist Dr. Chris DeArmitt and he presented literature which shows that plastics (mainly PE, PP, PVC, and PET) only account for 1% by volume (0.4% by weight) of society’s material use. Ceramics (mainly concrete) represent 84%, natural materials like wood 9%, and metals 6%. Global plastics consumption is around 370 million metric tons per year, however this is still small compared  to the 90 billion metric tons of overall materials used [1]. In order to put things better into perspective, we can compare the overall amount of materials used to a watermelon and compare it to a blueberry, representing the yearly plastics consumption (Figure 1). 

Figure 1: Watermelon vs blueberry - comparing the overall material consumption to the plastics consumption (on a yearly basis) [1].


How much do plastic products contribute to my total carbon footprint?

The short answer is: not much - only 1.3 % according to the study conducted by Carbon Trust in 2009 [3].  The 1.3% are 13,7 tons CO2-equivalents per capita. Recreation and leisure activities represent 18% of the total consumer carbon footprint, followed by space heating with 14%. Figure 2 shows the complete overview of the total consumer carbon footprint.

Figure 2: The role of  plastic products in the total carbon footprint of consumers [3].

Conclusions

Combining the answers of the two aforementioned questions, we can conclude that focusing on replacing plastics, which only represent 1% by volume of all materials, is not the best way forward to protect our environment. Concrete and ceramics represent 80% of the materials and they are the biggest pile which we need to attack first. Also, improving space heating systems with modern heat pump systems can reduce the personal carbon footprint much more than trying to not use a plastic bag for shopping. Allover, plastics are part of the solution to protect the environment and not the problem. 

I wrote another post on how plastics protect our climate and environment by using them as insulating materials - here you can read the whole post. 

Thanks for reading and #findoutaboutplastics

Greetings, 

Herwig Juster 

Interested in having a second opinion on your material selection and high performance polymers or  discuss with me about your current sustainability, 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

Interested in our material solutions - check out our product page here



Literature:

[1] Materials and the Environment: Eco-informed Material Choice 1st Edition

[2] https://phantomplastics.com/why-is-plastic-bad-for-the-environment-get-the-facts-in-5-minutes/

[3] https://plasticseurope.org/wp-content/uploads/2021/10/201009-Denkstatt-Report.pdf

Sunday 11 February 2024

Practical Examples on Sustainability from Plastics Industry: Polyamide-based plastic waste recycling - the new DIN SPEC 91481 standard, PA 6 textile-to-textile recycling, and bio-based High Temperature Polyamides (PPA)

Hello and welcome to a practical example on sustainability from the plastics industry (check out here the downgauging of PE-films in plastic garbage bag applications). Today we discuss three recent examples on Polyamide recycling and bio-based Polyamides. Let us start with the new DIN SPEC 91481 standard which aims to handle Polyamide recyclates along the value chain (from manufacturer over processing companies to OEMs) in an easier way. 

Example 1: What is the DIN SPEC 91481 and how can it help to advance recycling?

DIN SPEC 91481, is a new standard for recycled plastics, and has been introduced by the German Institute for Standardization (DIN). Based on data quality norms for usage and digital trading, the standard specifies requirements for the classification of recovered plastics and polyamide-based plastic waste. The goal of the standard is to facilitate the trading of polyamide recyclates by producers and processors. A group of 19 academic and business organizations, including Cirplus, the biggest internet marketplace in Europe for recycled plastics, worked together to create the standard. 

The standard includes requirements for Digital Product Passports (DPP) for waste and recyclables, definitions that improve clarity in waste-to-product-to-waste value-chains, Data Quality Levels (DQLs) for plastic recycles and waste feedstock, and suggestions for data collection, processing, and transmission throughout the entire life-cycle. The new standard is based on the methodology developed in DIN SPEC 91446, and is  adopted by the Association of the German Automotive Industry (VDA) too.

In terms of material selection for projects where your OEM or customer demands the usage of a recycled Polyamide, this standard will support you in the material comparison phase as well as sourcing phase. 

Example 2: Polyamide 6 textile-to-textile recycling is advancing too

Recently BASF and Spanish cloth manufacturer Inditex have launched loopamid®, a polyamide 6 (PA6) made entirely from textile waste. This innovative technology breaks down textile waste into monomers, which are then repolymerized to create new PA6 fibers and materials. Zara has incorporated loopamid® into its jackets, demonstrating its "design for recycling" approach. This move is a significant step forward for the fashion industry, in order to reduce tehri environmental footprint. 

Figure 1: From waste to new clothing: Polyamide 6 textile-to-textile recycling is advancing and shows commercial applications [2]. 

Example 3 - Bio-polyamides: advancement in bio-based high temperature Polyamides (Polyphthalamide PPA)

Another example is from Cathay Biotech which has developed a one-step bio-based high-temperature polyamide (Polyphthalamide PPA) preparation method, claiming to reduce polymerization time to less than 1% of conventional methods. This technology allows for controllable product melting point adjustments within the 290-310°C range. They have also produced a high-performance bio-based thermoplastic fiber composite with high glass fiber of 70 wt%, delivering environmentally conscious solutions in logistics, transportation, new energy, and construction fields. 

In the past I made a five blog post mini-series on bio-Polyamides: 

Part 1: PA 5.6 and 5T (Chemical Structure, Production, Properties, Applications, Value Proposition)

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

Part 3: Sustainability Facets (Bio Sourcing, LCA, Certifications) and Example Polyamide 6.10

Part 4: Application of Bio-Polyamides in Different Industries

Part 5: Performance Review of Short- and Long-Chain Aliphatic Homo- and Copolymer Bio-Polyamides

Thanks for reading and #findoutaboutplastics

Greetings,

Herwig Juster 

Interested in having a second opinion on your material selection and high performance polymers or  discuss with me about your current sustainability, 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

Interested in our material solutions - check out our product page here




Literature:

[1] https://www.sustainableplastics.com/news/germany-introduces-new-standard-recycled-polyamide

[2] https://www.texspacetoday.com/basf-and-inditex-make-a-breakthrough-in-textile-to-textile-recycling-with-loopamid/

[3] https://www.linkedin.com/pulse/cathay-biotechs-progress-report-bio-based-high-zu4bc?trk=article-ssr-frontend-pulse_more-articles_related-content-card


Wednesday 31 January 2024

Design Properties for Polymer Engineering: Comparative Tracking Index (CTI) after heat aging and moisture treatment (PA 6.6, PBT, and PPS)

Hello and welcome to this post on design properties for plastics engineering. In this post we deep dive into the Comparative Tracking Index (CTI) of aliphatic Polyamides, Polybutylene terephthalate (PBT) as well as Polyphenylene sulfide (PPS) used for electronic components made out of plastic. 

In previous posts we discussed the CTI of high performance polymers such as PPS and how we can improve it. The values shown in past posts were estimated according to the standard IEC-60112.

What is the Comparative tracking index (CTI) and why the CTI is important?

In general, when the plastic surface, which is the insulation material, carbonizes due to voltage exposure,  a conducting path is formed and tracking occurs. Over time, the surface erodes and a conduction of electricity takes place continuously. The resistance to the occurrence of tracking and erosion is represented by the Comparative tracking index (CTI).

How is the CTI value changing if flame retardant additives and glass-fiber reinforced are added to PA and PBT?

Figure 1 compares the CTI values of Polyamide 6 (PA 6), Polyamide 6.6 (PA 6.6) and Polybutylene terephthalate (PBT) with and without reinforcements, as well as with and without halogen free flame retardants. For Polyamides and PBT, adding reinforcement is not leading to a decline in CTI performance. PBT shows a decline in CTI performance in case flame retardants are added. 

Figure 1: CTI of PA 6, PA 6.6 and PBT with and without reinforcements, as well as with and without HFFR [1].

How is the CTI of PA, PBT, and PPS changing after heat aging and moisture influence?

Figure 2 [2] shows the results of the CTI measurements on untreated and treated PA 6.6, PBT, and Polyphenylene sulfide (PPS) samples (all with glass or glass/mineral reinforcement). For heat aging and moisture influence, the samples were exposed to 85°C at 85% relative humidity for 1,000 hours (in line with the international standards e.g. IEC 60068) .  PA 6.6- GF33 wt% (Zytel® 70G33L) and PBT-GF30 wt% (DURANEX® CG7030) reached in the untreated test scenario the maximum achievable value of 600 V. PPS-(GF+MF) 65 wt% (TEDUR® HTR PPS 2465) reached 500 V in the untreated test scenario. After the heat aging and moisture treatment, PA 6.6 and PPS did not show a decline in CTI performance. The advantage of Polyamides is their molecular structure which enables an inherent resistance to tracking and erosion. Achieving a 500 V level with PPS needs for example a special additive modification which we discussed here. PPS has a CTI in the range of 250 V.  In hot and humid environments, PBT showed a decline in CTI; however, it can still keep the CTI above 500 V. 

Figure 2: CTI of PA 6.6, PBT, and PPS before and after heat aging and moisture treatment (85°C/85%RH/1000h) [2]. 

Additional influences on CTI performance - part surface structure

Apart from moisture and temperature influence, part surface influences the CTI performance of your plastic part too (Figure 3). In case of PPS (Tedur HTR), a highly polished surfaces an increase the CTI from 500 V to 550 V [3]. on the other hand, rough surface structures such as the K29 and K30 (Knauf Industries), decrease the CTI value from 500 to 450 V [3]. 

Figure 3: CTI of PPS and influence of different surface finishes onto the CTI value [3].

Conclusions

CTI plays an important role when designing electronic components such as busbars for traction motors and power electronics. Selecting the optimal polymer material which can withstand temperature, humidity, time and mechanical impacts is key in order to make your design compact and safe without having short-circuits in the long run. 

Thanks for reading & #findoutaboutplastics

Herwig Juster 

Interested in having a second opinion on your material selection and high performance polymers or  discuss with me about your current sustainability, 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

Interested in our material solutions - check out our product page here




Literature:

[1] https://en.kunststoffe.de/a/specialistarticle/against-the-current-2586918

[2] https://www.polyplastics.com/en/product/lines/pbt_pa66/index.html

[3] https://www.plastverarbeiter.de/markt/elektroniktauglich-polyphenylensulfid-compound-mit-hoher-kriechstromfestigkeit.html


Monday 15 January 2024

Chlorine Based Plastics: PVC vs PVDC (Specialty Materials Know-How)

Hello and welcome to this blog post in which I discuss the differences and similarities of PVC and PVDC, as well as the unique barrier properties of PVDC. 

Re-cap: what is PVC? 

Poly(vinyl chloride) is an amorphous  thermoplastic polymer consisting of carbon (C), hydrogen (H) and chlorine (Cl) and PVC is, after polyolefins, the second largest plastics material group. Since the molar weight of this polymer contains 56.7% of chlorine [1], it uses  less petroleum and gas feedstock  for its production in comparison to other polyolefins. This elevated content of chlorine also provides PVC with flame-retarding properties. As a result, PVC holds the lead in civil- and construction  engineering applications, such as isolations and floorings. Apart from the construction sector, PVC plays an important role in medical device applications, where it ranks right after the Polyolefins in overall usage. A blog post on detailed applications using PVC in medical device applications can be found here

What Is Polyvinylidene Chloride (PVDC)?

PVDC fulfils not the classic definition of high heat/performance polymers (UL 746B - polymers need to withstand a continuous use temperature of 150°C for 100,000 hours), however we can classify it as a special polymer, based on its unique set of properties. 

PVDC, chemically defined as 1,1-Dichloroethene, has a temperature usage range from -20°C up to +100°C (from 160°C on chemical-thermal degradation starts, resulting in hydrogen chloride). The additional Chlorine results in a semi-crystalline morphology, whereas PVC is an amorphous polymer.

What is the difference between PVDC and PVC?

Figure 1 shows the chemical structure of PVC and PVDC. It can be seen that PVDC contains double the amount of chlorine compared to PVC. The combination of symmetric Chlorine leads to a high barrier towards oxygen and water vapor as well as superior flame retardancy performance. Figure 1 also contains the oxygen permeability of PVOH, EVOH, PVDC, and R-PVC. PVOH and EVOH perform slightly better than PVDC, however if you combine it with the water vapor chart, things look differently. PVDC has a low water vapor permeability compared to PVOH and EVOH. This allows you to have a material which has excellent oxygen and water vapor resistance which can be used for several interesting applications.

Figure 1: Chemical structure of PVC and PVDC, together with oxygen and water vapor permeability [5].

PVDC applications

PVDC is mainly used as film for packaging applications and as waterborne high-barrier resin dispersion which allows coating of textiles, paper, and plastics. 

For packaging, the combination of oxygen and water vapor barrier play a role for fresh and processed meat packaging, together with dry fruit, seafood and vegetable packaging. 

In the field of medical packaging, PVDC is used for pouching systems.

Also wine bottle caps use PVDC as a barrier layer. The well known Stelvin wine caps use a Saranex™ liner based on a PVDC [7]. 

Conclusions

To summarise, PVDC is a high barrier polymer with outstanding gas barrier and water vapor properties. This unique combination of properties makes it an optimal material choice during your material selection journey for advanced packaging and medical film solutions. Apart from PVDC, PARA (MXD6) has also interesting barrier properties which we discuss in the post here

Thanks for reading and #findoutaboutplastics

Greetings, 

Herwig Juster

Interested in our material solutions - check out our product page here

Interested to talk with me about your polymer material selection, sustainability, 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.


Literature: 

[1] W. Kaiser: Kunststoffchemie für Ingenieure: Von der Synthese bis zur Anwendung, Carl Hanser (2011)

[2] https://www.findoutaboutplastics.com/2015/02/pvc-not-always-in-best-spot-but-still.html

[3] https://www.findoutaboutplastics.com/2017/03/my-top-5-commodity-plastics-for-medical_23.html 

[4] https://us.metoree.com/categories/5347/

[5] https://www.syensqo.com/en/brands/ixan-pvdc/faq

[6] https://www.amcor.com/stelvin


Saturday 6 January 2024

Design Properties for Engineers: Superior Gas Barrier Properties of PolyArylAmide (PARA; MXD6)

Hello and welcome to this new blog post. We discussed several outstanding properties of PolyArylAmide (PARA; MXD6) in detail here

However, another impressive property is the superior gas barrier against oxygen and carbon dioxide in film applications. PARA is able to outperformance other commercial available Polyamides, and can compete with well established materials such as ethylene-vinylalcohol copolymers (EVOH),acrylonitrile copolymers (PAN) and vinylidenchloride copolymers (PVDC). 

Film extrusion and crystallization speed of PARA (MXD6)

PARA crystallizes similarly to PET allowing PARA to stay in an amorphous state easily if it is cooled immediately after the extrusion or injection moulding process. 150°C to 170°C is the temperature range where PARA crystallizes the fastest.  The moderate crystallization speed opens up a wider operation window compared to other Polyamides in the thermoforming or the orientation process for film making.

Gas barrier properties 

Figure 1 shows the oxygen permeation rate of PARA (MXD6) films (stretch ratio 4x4) and other barrier polymers. The data indicates that the oxygen barrier property of PARA is much less moisture sensitive than that of EVOH. PARA with its high heat stability and wide processing window can be co-extruded and co-injection moulded with PET, PP, and PE in order to make multilayer containers or films.  Also, the gasoline barrier properties are outstanding and therefore it is used in the fuel system of Internal Combustion Engines (ICE) cars. In case the Polyamide will be coated with PVDC, moisture influence can be kept on a stable level. In another post we will discuss the oxygen and water barrier properties of Polyvinylidene chloride (PVDC). 

Figure 1: oxygen permeation rate of PARA-MXD6 films compared to EVOH and PA 6 (PVDC coated) [1].

In case you want to read more on PolyArylAmide - check out "The ABCs of Polyarylamide (PARA; MXD6)".

Thank you for reading this post and #findoutaboutplastics.

Greetings,

Herwig Juster

Interested in our material solutions - check out our product page here

Interested to talk with me about your polymer material selection, sustainability, 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.


Literature:

[1] https://www.fostercomp.com/wp-content/uploads/2018/11/MX-Nylon_properties.pdf

[2] https://www.syensqo.com/en/brands/ixan-pvdc/properties

[3] https://us.metoree.com/categories/5347/


Monday 1 January 2024

Plastic Part Marking Codes of Aliphatic and Semi-Aromatic Polyamides (ISO 16396-1:2022 -prev. ISO 1874)

Plastic Part Marking Codes of Polyamides 

Hello and welcome to the first post of the new year 2024! I hope you had a great Christmas break and I welcome you all back to a new exciting year of polymer engineering topics. 

Let us start with a community question which is about the part marking codes for Polyamides, in particular the ISO 16396 (previously ISO 1874). 

In my previous posts I discussed mainly the ISO 1043 for part marking since it covers all polymers. However, apart from the ISO 1043, the ISO 16396 was established to deal with the wide range of Polyamides. 

What is the ISO 16396 (previously ISO 1874) exactly?

The ISO 16396-1:2022 (prev. ISO 1874) [1]: Polyamide moulding and extrusion materials was introduced particularly for Polyamides used in injection moulding and extrusion (PA 6, PA 66, PA 69, PA 610, PA 612, PA 11, PA 12, PA MXD6, PA 46, PA 1212, PA 4T, PA 6T and PA 9T and copolyamides of various compositions for moulding and extrusion). 

The designation consists out of five data blocks:

-Data block 1: identification of the plastic by its abbreviated term (PA), and information about the chemical structure and composition

-Data block 2: position 1: Intended application and/or method of processing; positions 2 to 8: Important properties, additives and supplementary information

-Data block 3: designatory properties

-Data block 4: fillers or reinforcing materials and their nominal content

-Data block 5:  contains additional information which may be added if needed

Example: PA6T/66 MH, 14-190, GF50

PA6T/66: Polyamide 6T which is a homopolymer based on terephthalic acid (TPA) / hexamethylenediamine together Polyamide 66 which is based on hexamethylenediamine and adipic acid. 

M: injection moulding; H: heat ageing stabilized

14-190: viscosity number (in ml/g) > 130 but below 150; 190: tensile modulus of elasticity between 17000 MPa and 20000 MPa

High heat Polyamides - plastic part marking examples

In Table 1 I summarized commonly used high heat Polyamides which allows you to quickly identify the plastic used for a certain part or to use it for your next project where in the end the part marking question may come up.

Table 1: High heat Polyamides - plastic part marking examples.

Data block 1 Data block 2 Data block 3 Data block 4 Description
PA6T/6I MH 12-110 GF30 PA based on TPA (6T) and IPA (Isophthalic acid; 6I) with 30 wt% glass fiber; injection moulding; heat stabilized;viscosity number >110-130; Elastic modulus >10.5 -11.5 GPa
PA6T/66 MH 14-250 CF30 PA based on TPA (6T) and PA 6.6 with 30 wt% carbon fiber; injection moulding; heat stabilized; viscosity number >130-150; Elastic modulus >23 GPa
PA 10T/X MH 14-100 GF30 PA based on 1,10-decamethylene diamine (10) and terephthalic acid (T) with 30 wt% glass fiber; injection moulding; heat stabilized; viscosity number >130-150; Elastic modulus >9.5-10.5 GPa
 


More examples of part marking codes for different plastics compounds can be found here and for PolyArylAmides here. I wrote a miniguide on this topic too, which can be downloaded here.

Thank you for reading and #findoutaboutplastics

Greetings

Herwig Juster

Interested in our material solutions - check out our product page here

Interested to talk with me about your polymer material selection, sustainability, 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.


Literature:
[1] https://www.iso.org/standard/81940.html