Wednesday 20 July 2022

Highly Filled PP Compounds - Materials for Improved Flame Retardancy, Cost, and Functionality

Highly Filled Polypropylene Compounds 

Hello and welcome to a new blog post. Today we discuss highly filled PP compounds as enabler materials for improved flame retardancy, cost, and functionality.

Some time an industry colleague said to me that if the application does not have a high temperature and precision demand, most of them will end up made out of Polyolefins (PP, PE): “PP can do the job”.

And we see more and more engineering polymer replacements (PA, PC, PBT) by PP with fillers (functional or non-functional). Therefore, let us have a look at highly filled PP compounds. 

Which types of highly filled Polypropylene are there and what are some major application fields for highly filled Polypropylene?

As a first overview we can cluster them in three groups: 

-Calcium carbonate filled PP: main drive is cost out and improved dimensional stability; calcium carbonate belongs to one of the most used inorganic fillers which increases the modulus of elasticity. Loading levels of 30 parts per hundred result in 11 % by volume. 

-Mineral filled flame retardant PP: main driver  is to comply with more stringent flame retardant requirements; Magnesium Hydroxide (MDH) can be used as flame retardant. 

-Graphite filled PP: main driver are Electrostatic discharge (ESD) applications such as fuel connectors, and fuel cell applications.

What filler levels can be realized?

For reaching certain stringent flame retardancy ratings with PP compounds, filler levels of flame retardant filler MDH can be 60-65% by weight. This would result in a composite density of 1.45 g/cm3. However, the balance need to be found between property reduction and processing capability. 

How to increase filler amounts to improve performance?

New technologies such as the patented PlastFormance technology (Guest interview here) allows loading a base polymer up to 80% weight and keeping still good flow capabilities for injection moulding. 

Examples of PP replacing engineering polymers

Also, we see talcum filled PP (min. 20% by weight) replacing ABS and long-glass fiber filled PP replacing short glass fiber PA.

Key for highly filled compounds is the understanding of filler shape, their size and how their surface is treated to be able to make a proper bonding with the base polymer. Using such compounds helps to enlarge your repertoire for polymer material selection

Thank you for reading and #findoutaboutplastics



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.
New to my Find Out About Plastics Blog – check out the start here section



[2] Introduction to Polymer Compounding  Raw Materials, Volume 1 by Natamai Subramanian 

No comments:

Post a Comment