Photo by BASF BASF has expanded its polyamide portfolio for charge air duct applications in engines

BASF has developed Ultramid Advanced N to meet increasing demands placed on polyamides in automotive and electronics applications writes David Eldridge in this feature for Plastics News Europe.

Polyamide producer BASF (Hall 5 Stand C21/D21) has launched a new range of high-performance polyphthalamides (PPA), forming a centrepiece of the German group’s new engineering plastics showcase at K 2016.

The new Ultramid Advanced N materials “exceed the properties of conventional PPA plastics”, particularly in terms of dimensional stability, according to BASF.

“Advanced N is a new superhero for engineers, for our customers. BASF is very committed to the PPA market,” said Abdullah Shaikh, head of PPA materials in BASF’s Performance Materials Europe business.

BASF has been active in PPA since it launched its Ultramid T product line over 25 years ago. The Advanced N products have been developed in response to the trends for downsizing and increasing operating temperatures in sectors such as automotive, electronics and white goods.

“Today we see new trends coming up in the market, [including] miniaturisation, which means basically downsizing,” said Shaikh at a pre-K press event at Messe Düsseldorf in June. “You all remember how a mobile phone looked five to ten years back, and today how they look is completely different. They are a lot more compact, the performance is even better. This requires materials that can withstand higher temperatures and still perform and be safe, that can be moulded into smaller shapes, that can be functionally integrated into an entire system that delivers even better performance.”

In an automotive example, Shaikh said: “Gear wheels are being miniaturised. So they have higher performance requirements. They also are working under elevated temperatures.”

Ultramid Advanced N is suitable for small connectors and function-integrating housings. In electronics, applications are expected in the assembly of circuit boards using SMD (surface mounted device) technology, due to the PPA material’s lead-free soldering properties.

The Ultramid Advanced N portfolio includes unreinforced compounds and compounds reinforced with short or long glass fibres, as well as flame-retardant grades. BASF said its new materials exceed the properties of competitor PPAs, due to “constant mechanics” up to 100°C, “outstanding” chemical resistance and low water absorption as well as low friction and wear. The materials enable short cycle times and a wide processing window, the group said.

Low water uptake is “best in class”, said Shaikh, which leads to “excellent” dimensional stability. In his presentation, he showed a slide that compared Ultramid Advanced N with PA6T, both 35% glass-filled. In a moisture uptake test at 70°C and 62% relative humidity, the PA6T material had twice the amount of water uptake as Ultramid Advanced N, according to the slide.

“This means it can be used to manufacture very small, high precision parts,” said Shaikh.

Among the chemicals that Ultramid Advanced N shows high resistance to are hot oil, coolants, calcium chloride and fuels with a high methanol content. The individual grades have different heat stabilizers and are tailor-made for particular requirements of the automotive, electrical and electronics industries.

The flame-retardant grade reinforced with 30% glass fibres was subjected to alternating climate tests, and, according to BASF, “proved to be superior to corresponding market PPA grades as far as its tendency to migrate is concerned”.

The non-halogen flame retardant has a V-0 rating in UL94 tests at 0.4 mm. The material also displays “excellent” creep resistance, a good surface finish and is laser-markable, said BASF.

The trend for downsizing is particularly apparent in cars, where smaller capacity engines are being made to perform with better optimisation through the addition of turbochargers. BASF managers at the June press event discussed the group’s PA portfolio which it has tailored for the higher pressures and temperatures in charge air ducts.

Andreas Stockheim, segment manager for powertrain, said the engine downsizing trend is part of car makers’ response to global regulators setting tougher emissions targets. By 2020, each car maker’s vehicle range, on average, is required to meet the following CO2 targets: 95 g/km in the European Union, 105 g/km in Japan, 117 g/km in China and 140 g/km in the USA.

Stockheim showed a slide indicating the main areas where car makers are reducing CO2 emissions from an average of 130 g/km in 2015 to reach the EU target of 95 g/km. Engine optimisation is expected to be the biggest contributor, with a 25 g/km reduction, while body lightweighting is expected to deliver 5 g/km and electrification another 5 g/km in reductions.

Matthias Scheibitz, head of the product development team for Ultramid PA materials, discussed the portfolio of high performance materials which BASF has developed for various temperature requirements of the charge air duct. The range comprises PA6, PA66 and PA66/6 grades with a glass fibre content between 30 and 50%.

A new addition to the portfolio is Ultramid B3WG6 GPX, a PA6 containing 30% glass fibre, which is resistant to temperatures up to 180°C and for a short time up to 200°C. It is suitable for air intake manifolds made from several parts, due to its performance in burst pressure and weld strength.

Ultramid Endure materials cover the upper end of the temperature range and it can stand constant use temperatures of 220°C and peaks up to 240°C. The injection moulding grades Ultramid Endure D3G7, with 35% glass fibre reinforcement, and D3G10, with 50% glass fibre reinforcement, have found applications in air intake manifolds of turbocharged diesel engines as well as in resonators and sensors. OEMs use Ultramid Endure D5G3 BM, with 15% glass fibre, for blow moulded charge air pipes, said BASF.

For temperatures between 180°C and 210°C, the Ultramid portfolio contains PA66 plastics with enhanced heat stabilization. These include grades Ultramid A3W2G6 to G10 (with glass fibre reinforcements from 30 to 50%) for temperatures up to 190°C, for example in charge air cooler endcaps.

BASF has launched the new Ultramid A3W3G7 PA66 for temperatures up to 210°C. It said this material fills in the gap between the Ultramid A3W2 grades and Ultramid Endure. The material shows “very good” mechanical properties at constant use temperatures up to 210°C, it said.

The importance of weld and burst pressure strength was underlined by BASF, as welded components are frequently used in the engine. The group uses a number of testing methods to assess long-term strength and make sure performance of the Ultramid materials are “outstanding”.

It has developed the Ultrasim Weld Tester, a complex test specimen to determine the fatigue strength of weldlines under various long-term loads. It also enables a more precise prediction of the part’s service life using BASF’s Ultrasim simulation tool. BASF said the simulation helps customers to create an optimum design for their components at an early stage of development, to reduce development loops and the amount of prototypes.