Tuesday, 20 September 2022

Flame Retardant Classifications According DIN EN ISO 1043-4 - What do they mean?

Hello and welcome to a new blog post. In a previous post we discussed flame retardants in a general way, followed by examples of flame retardants for Polyamides. In this post we uncover the flame retardant classification according to DIN EN ISO 1043-4.

Example of a part marking code with flame retardant

Let us begin with an example and let us decode it step-by step: PE-LD FR (30+40) 

PE-LD: Polyethylene with low density

FR (30+40): contains flame retardant form classification 30 and 40

What does the classification FR(30+40) mean?

To find out we need to have a look into the DIN EN ISO 1043-4 where we can find the different flame retardant types. 

Figure 1 shows an extract of the most common flame retardant classes. We can distinguish between halogen compounds, nitrogen compounds, halogen-free organophosphorus compounds,inorganic phosphorus compounds, metal oxides, Boron and zinc compounds, silicon compounds, and graphite.

Figure 1: extract of the most common flame retardant classes according DIN EN ISO 1043-4

Cycling back to our example, we can state that this PE-LD uses nitrogen compounds (3) and halogen-free organophosphorus compounds (40) as flame retardants.

In case you want to overmould copper (busbar application) with a Polyamide which needs a certain flame retardant level, attention should be given to use flame retardants from classification 40. Such flame retardants do not create electrical corrosion on your part which in turn can cause a short circuit. 

In market segments such as automotive, more and more flame retardant material in combination with other properties like thermal conductivity are used. Using Figure 1 during material selection can help to prevent part failure in the long run for example due to electrical corrosion (migration of flame retardants on surface). 

Thank you for reading and #findoutaboutplastics

Greetings, 

Herwig 

Interested to talk with me about your polymer material selection, sustainability, and part design needs - here you can contact me 

Subscribe to my Polymer Material Selection book launch page 

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

Literature:

[1] https://www.findoutaboutplastics.com/2022/06/flame-retardants-why-do-we-need-them.html

[2] https://webstore.ansi.org/Standards/DIN/dineniso10432016-1640336

[3] https://www.wikiwand.com/de/ISO_1043

[4] https://plastics-rubber.basf.com/global/en/performance_polymers.html


Sunday, 11 September 2022

What Should be the Minimum Transparency Level Required for Plastic Laser Welding? (Community Question Answered)

 Hello and welcome to a new blog post. Today we discuss a question I received regarding plastic laser welding. The basics of plastic laser welding I described herein this post which includes an introduction training video too. 

What should be the minimum transparency level required for plastic laser welding?

In general, thermoplastics transmit a near-IR beam. The upper plastics layer needs to have transparency for wavelengths between 808 nm – 1064 nm. A minimum transmission rate of 5% is required, however optimal would be 30% and greater (Figure 1). 

That means in an optimum application case,  30% of the laser energy passes through the transparent upper layer and is absorbed by the lower layer. Additives, fillers, pigments, and part thickness can negatively influence the transmissivity of your upper layer. Therefore, careful polymer material selection for laser welding is needed. 

Figure 1: Plastic laser welding - minimum and optimum transparency level of upper layer

Thanks for reading and #findoutaboutplastics

Greetings, 

Herwig 

Interested to talk with me about your polymer material selection, sustainability, and part design needs - here you can contact me 

Subscribe to my Polymer Material Selection book launch page 

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

Literature: 

[1] https://www.findoutaboutplastics.com/2021/03/joining-techniques-laser-welding-of.html

[2] https://youtu.be/0T_sQwbWFMA

[3] https://www.solvay.com/en/product/amodel-1145-hs-lzt-bk-979

[4] https://www.lpkfusa.com/articles/lq/LPW_GL_Hybrid_Laser_Wedling_Design_Guidelines.pdf

Tuesday, 6 September 2022

Ways to Increase the Comparative Tracking Index (CTI) of Thermoplastics (Community Question)

Hello and welcome to a new blog post. I received a question on how to improve the Comparative Tracking Index (CTI) of thermoplastics and in this post we will discuss this question since it can be of value for the whole community. 

The basics of CTI and its measurement I discuss in this training video. 

In general, there are polymers which more likely form a conducting carbonized path compared to other polymers. Aliphatic and semi-aromatic polymers, polyolefins, fluoropolymers, as well as polyesters show high resistance to form a conductive carbonized path. PPS on the other hand more likely forms a conducting carbonized path, combined with a low tracking resistance. Important in this context are the two standards IEC 60112 and UL 746 which are used in several industries to rank CTI of polymers. Figure 1 shows an overview in which CTI class (IEC and UL) different thermoplastics can be placed. 

Figure 1: Overview CTI of different thermoplastics


Ways to improve the CTI value

-Use a mineral flame retardant: By adding 8 weight % of mineral flame retardant to a PBT, CTI could be increased 13%.  Example is the ACTILOX® 200SM (Nabaltec).

-Use additives: there are multi-functional polyester modified siloxane additives which can be used to improve the CTI of various engineering compounds. Example is the TEGOMER® H-Si 6441 P (Evonik).

-Blending with a high CTI polymer: in the case of PPS, adding polyamide can improve the CTI value from 175 V (PPS-GF40) to 275 V (PPS-GF40+PA). Example is the Ryton XK2430 (Solvay). 

Electrical design properties such as the CTI is important during the material selection of components  for e-mobility and electronic applications. Choosing the optimal polymer can lead to a more compact design which is the case for busbars overmoulded with a thermoplastics. A high CTI polymer allows you to shorten the distance between the busbars. 

Thanks for reading and #findoutaboutplastics

Greetings, 

Herwig 

Interested to talk with me about your polymer material selection, sustainability, and part design needs - here you can contact me 

Subscribe to my Polymer Material Selection book launch page 

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

Literature: 

[1] https://www.toray.eu/eu/plastics/torelina/technical/tec_021.html

[2] https://www.plastic-additives.com/en/application-areas/cable-electronics

[3] https://nabaltec.de/fileadmin/user_upload/03_produkte/03-3_boehmit/nabaltec_tds_actilox-b30-b60-200sm.pdf

[4] https://www.solvay.com/en/product/ryton-xk2340

[5] https://www.youtube.com/watch?v=LzFyKr-SUZQ


Monday, 29 August 2022

HDPE Plastic Bag Degradation - The Experiment Update 2022

Hello and welcome to a new blog post. Today I will give you an update on my HDPE plastic bag degradation experiment

This summer I spent some weeks in our apartment flat in Sesimbra, Portugal which by the way you can rent for your holiday as well.  I used this time to check on my experiment which I started in January 2021. 

Flashback: experiment setup 

I cut a 240x160x0.1 mm part out of a standard HDPE bag and put it in a marmalade glass which is filled with seawater from the California beach of Sesimbra. I stored it in a room without the influence of sunlight.

20 month later

In August 2022 I opened the marmalade glass again and removed the HDPE piece. I checked it for damages such as cracks and holes. However, no visible damages could be found so far. Figure 1 shows the HDPE piece. After the check was finished I put it back and placed the glass in the dark room. If the glass would be impacted by sunlight, degradation may occur faster.  

Figure 1: Removed HDPE piece of plastic bag from sea water filled glass

I will give you an update in 2023 again. 

Generally, keeping in mind the four major factors (material, component design, part processing, service conditions) impacting plastic part performance during your polymer material selection and part design phase will decrease part failure in the long run.

Thanks for reading and #FindOutAboutPlastics! 

Greetings,

Herwig Juster

Interested to talk with me about your polymer material selection, sustainability, and part design needs - here you can contact me 

Subscribe to my Polymer Material Selection book launch page 

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

Literature:

[1] https://www.findoutaboutplastics.com/2021/01/hdpe-plastic-bag-degradation-experiment.html


Tuesday, 23 August 2022

Plastic Multipoint Design Data: Specific Heat Capacity as a function of Temperature

Hello and welcome to a new blog post. Today I will show you another set of multipoint design data: specific heat capacity as a function of temperature. 

In a previous post I presented to you the Global Warming Potential (GWP) as a function of the heat capacity. However, the heat capacity values were limited to one temperature only (20°C). 

Increasing the temperature of a polymer by a dT at constant pressure is the result of a specific amount of heat supplied to the system. This is referred to as specific heat. 

Figure 1 presents the specific heat of amorphous and semi crystalline unfilled polymers. With increasing temperature the specific heat of both amorphous and semi crystalline polymers is increasing.

 

Figure 1: Specific heat capacity Cp as a function of temperature of amorphous and semi crystalline unfilled polymers.

There are several calculations in polymer engineering where the specific heat value of a certain polymer is needed: 

-calculation of the pressure drop along the gate or runner of an injection mould 

-dimensioning extrusion dies

-thermal design of moulds

-predicting the flow length of spiral melt flows

-polymer material selection for thermal management applications (thermal diffusivity)

Here you can find further design property data of various polymers for your part design and material selection. 

Thanks for your reading and #findoutaboutplastics

Greetings,

Herwig Juster

Interested to talk with me about your polymer material selection, sustainability, and part design needs - here you can contact me 

Subscribe to my Polymer Material Selection book launch page 

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

Literature: 

[1] VDI Wärmeatlas

[2] Griesinger: Wärmemanagement in der Elektronik

[3] Natti: Design Formulas for Plastics Engineering 


Wednesday, 17 August 2022

Plastic Multipoint Design Data - CLTE of Polymers as a Function of Temperature

Hello and welcome back to a new post. Today we continue with polymer property data as a function of time. Multipoint data play a key role during material selection and part design. Properties over a temperature range are especially interesting for us part designers. 

In a previous post we discussed the Coefficient of Linear Thermal Expansion (CLTE) of unfilled and filled polymers at room temperature (20°C). Here you can find the post and the data

CLTE of unfilled polymers as a function of temperature

The Figure 1 below shows the CLTE values of amorphous and semi crystalline unfilled polymers. With increasing temperatures we see higher thermal expansion due to the easier movement of the polymer chains. It is important to check the CLTE of your selected material at operating temperature too. This will avoid unexpected part failures. Also, if metal overmoulding is done, such a check is in particular important. 

Figure 1: CLTE of unfilled polymers as a function of temperature

Here you can find further design property data of various polymers for your part design and material selection. 

Thanks for your reading and #findoutaboutplastics

Greetings,

Herwig Juster

Interested to talk with me about your polymer material selection, sustainability, and part design needs - here you can contact me 

Subscribe to my Polymer Material Selection book launch page 

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

Literature: 

[1] VDI Wärmeatlas

[2] Griesinger: Wärmemanagement in der Elektronik

[3] Hanser Kunststofftaschenbuch

[4] https://www.findoutaboutplastics.com/2022/07/plastic-part-design-properties-for.html


Monday, 8 August 2022

Plastic Multipoint Part Design Data - Thermal Conductivity of Polymers as a Function of Temperature

 Hello and welcome to a new blog post. Today we discuss the thermal conductivity of amorphous and semi-crystalline polymers (unfilled; only the polymer resin) as a function of temperature.

The importance of multi-point data

Multipoint data of different polymer and polymer compound properties prevail information which would otherwise may be overlooked during material selection and product design. 

In other posts we discussed multi-point data such as the DMA results of engineering and high performance polymers. Multi-point data are important for material selection since it has a lot to do with thinking in relationships of time-dependency and temperature-dependency behaviors. Graphically such behaviors can be better accessed. Single point data can lead to misjudgment and negatively impact the material selection process.

Thermal conductivity of polymers was already several times topic on this blog: 

-Thermal conductivity of filled and unfilled high performance polymers

-Thermal conductivity of 96 plastics for EV application design support

-Guest Interview: Max Funck from PlastFormance – “Our patented technology for innovative plastic compounds allows for high filler contents - up to 80% vol.”

-Polymer Chemistry meets A.I. – Finding and Developing New Polymers with Target Properties in the 21st Century

However, in those posts thermal conductivity mostly was discussed as a value estimated at one single temperature. Now we look how the thermal conductivity changes in a temperature range of -150°C and up to 150°C. There is no linear behavior of the different polymers in this temperature range. 

Amorphous polymers: thermal conductivity as function of temperature

Amorphous polymers: thermal conductivity as function of temperature

Semi-crystalline polymers: thermal conductivity as function of temperature

Semi-crystalline polymers: thermal conductivity as function of temperature

Here you can find further design property data of various polymers for your part design and material selection. 

Thanks for reading and #findoutaboutplastics

Herwig 

Interested to talk with me about your polymer material selection, sustainability, and part design needs - here you can contact me 

Subscribe to my Polymer Material Selection book launch page 

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

Literature: 

[1] VDI Wärmeatlas

[2] Griesinger: Wärmemanagement in der Elektronik

[3] Hanser Kunststofftaschenbuch