January 30th, 2023
In our company we work with high-performance polymers only. These plastics can withstand temperatures of up to 250 °C, are chemically resistant and also withstand high mechanical loads. Most of the components we produce, replace complex manufactured metal parts or are used in chemically, thermally and mechanically demanding environments where no other material could resist. The production volume of these materials is in the range of one percent of the total production of polymers worldwide. The technical advantages and subsequently the high price of the raw material make it a valuable resource that we use with care.
Reduce - Reuse - Recycle has been the basis of sustainable actions for decades. Avoiding the consumption of raw materials, reusing products and ultimately returning them to the material cycle. What must be viewed critically is the shift of responsibility to the end consumer. For quite some time the 3 Rs have gained a new mate: Rethink is the keyword we should consider first. It is a direct request to the manufacturers to thinking about sustainability right from the product design stage.
But how do you think more sustainable?
Actually, it starts with asking some simple questions about the product:
Let’s take the valve of a thermal module as an example to show you, how Re-think considers sustainability aspects as part of the product development.
The goal is to break down the complexity of an existing valve and focus on what the customer actually needs – the must-haves:
• Low actuation
• Continuously variable diverting of the liquid flow
• Low pressure difference
• Defined throughput
• Tightness of the overall system
• Low internal leakage
• Resistance to water-glycol mixture
• Temperature resistant up to 80 °C
• Durable mechanics
• Lean design
• No constriction of the hydraulic cross sections during the switching operation
Re-Think components, materials & design
To save material the design should feature a low wall thickness, but nevertheless be stable throughout the product lifetime. Stability can be reached by intelligent placements of ribs.
In order to facilitate repair and ultimately disassembly at the end of life, the housing can be closed with screw connections and sealed with a removable O-ring.
If the emphasis is more on weight reduction and mono-material-approach, the housing could also be welded shut, disregarding the O-ring and the screws.
Material options could be either polyphenylene sulfide or polyphthalamide. Both materials are easy to recycle and for PPA there are already bio-based types on the market. PPA as well as PPS are very well suited for contact with water-glycol mixtures and temperature resistant in the required range.
The design as a simple flap saves material and weight, while performing in an energy-saving manner compared to other valve-types.
Recycling is easier if the valve body and the housing are made of the same material - and issues with different thermal expansion and resulting leakage are eliminated as well.
Sealing elements in thermal management valves are often made of fluoropolymers. Those materials are flexible and resistant to chemicals and temperature, but unfortunately they are made of environmentally harmful monomers and additionally difficult to recycle.
We are currently researching alternative materials, which provide the required properties, but have less impact on the environment and can preferably be separated with standard methods when recycled.
The actuator is one of the few metal elements in the assembly, along with the body screws (if used). If it is disassembled at the end of its life, it can be removed without any problems. Even in the case of destructive disassembly, the metal elements can be extracted from the plastic parts using magnets.
In comparison to other valves available at the market our re-thought solution requires less components, less different materials and still outperforms these in several categories (?)
The Rethink approach only works as a whole. A material with a low carbon footprint (CFP) is of no benefit if the function suffers. A reduction of the number of components is not effective if the device cannot be recycled at its EOL.
The aim is and must be to provide the customer with a product that fulfills all functions without compromises. Nothing harms the sustainability approach more than products that fail prematurely due to poor design or inferior materials. For us, product development has to go hand in hand with a holistic approach to sustainability, including smart design and intelligent use of polymers in every component. This is one of the necessary steps to maintain our technological progress without exploiting and polluting our planet further.
Author: Melanie Kunz
Melanie Kunz has worked for SGPPL+S GmbH since 2014 and since 2016 as process development engineer with focus on horizon 2 and 3 projects. Experiences in Materials Science and a strong expertise in process development for injection molding production qualifies her as one of the leading members of our innovation team. With a strong focus on sustainability and environmental footprints she accompanies our transformation to e-mobility.
January 26th, 2023