LANXESS: Highly hydrolytically stable and laser-transparent PBT material allows car engines to breathe

Polybutylene terephthalate (PBT)-based compounds not only have high hydrolytic stability at high temperature and humidity, but also have good laser transparency in laser transmission welding, which is a special case
.
This is because these two material properties are usually mutually exclusive
.
However, LANXESS now offers a variety of PBT compounds that successfully combine both properties
.

An example is Pocan B3233HRLT (hydrolysis resistant, laser transparent), which has been used in a range of large-scale applications, for example in the manufacture of housings for electromechanical actuators for eddy current control
.
An automaker based in southern Germany is equipping several of its diesel engine series with these actuators
.
The actuators are developed and manufactured by Sogefi Air & Cooling SAS in Orbe, France
.
The company is part of the Italian conglomerate Sogefi SpA, one of the world's leading suppliers of automotive filtration systems, flexible chassis components and air intake and engine cooling systems
.

Cost-effective production process

Jean-Marie Olive, Application Development Specialist at LANXESS' High Performance Materials (HPM) business unit, said: "Our PBT compound was chosen because it can withstand the high temperatures under the hood of automobiles, even in very humid conditions
.
Our The material also features low warpage and high dimensional stability, properties that make it ideal for compact housings with these complex geometries
.
Even if the material is dyed black, it can still be used in plastics typically used for laser transmission welding.
A high level of transparency is provided in the laser wavelength range
.
This ensures stable and efficient welding of housing components
.
”

Excellent test results

Pocan B3233HRLT's excellent resistance to high temperature and humidity has been demonstrated in SAE/USCAR-2 Rev.
6 long-term testing, which is considered the world's leading test for hydrolytic stability of plastics, according to standards established by the Society of Automotive Engineers (SAE).
One of the most demanding tests
.
During multiple cycles, finished parts are exposed to intense temperature changes at up to 100% relative humidity
.
Jean-Marie Olive said: "In tests of samples under similar conditions, our compounds met the requirements of class 3 and were therefore able to withstand temperatures up to 125°C
.
"

Laser Transmission Welding - The Latest Trend

Laser transmission welding is a joining method for components made of thermoplastics
.
It is ideal for cost-effective and gentle production of extremely small parts with complex geometries, making it perfect for the trend towards miniaturization of electrical and electronic functions
.
The process uses the energy of a laser
.
The laser beam passes through a laser-transparent component and is absorbed by a second component below (usually black pigment)
.
The absorption generates heat, which melts the surface of the second component
.
Thermal conduction, in turn, softens the surface of the first component, creating a strong weld between the two components
.
As far as the actuator is concerned, the laser-transparent part is made of Pocan B3233HRLT with a laser-transparent black color, while the absorbing half of the housing is made of Pocan B3233HR
.

Optimizing the combustion process

Swirl control actuators are part of the internal combustion engine air management system
.
They are responsible for controlling the air supply to the intake module while ensuring adequate air turbulence
.
They help to optimise the combustion process and thus play a key role in ensuring that the engine is highly efficient, which is ultimately reflected in high fuel economy and correspondingly low consumption figures
.