Technical Insights
LANXESS High Performance Materials develops plastic solutions for numerous requirements. And it pushes the limits of what is feasible. With its PA6 Durethanes and PBT grades of the Pocan brand, HPM has developed materials that are on a par with PA66 – and in some cases even superior. Whether it is about improved impact strength, lower moisture absorption or significantly improved heat deflection temperature – HPM materials do a great job. And keep composure. Even at more than 150 °C.
Take a look what insights we offer for your challenges!
PA6 Performance: Cyclically loadable like a PA66.
Did you know…
…that the new polyamide 6 grades of the new Durethan Performance product family for cyclically permanently stressed components are several times more resistant to fatigue under pulsating loads than standard products with the same glass fiber content? Cyclic mechanical loads are a very special challenge for materials – the alternating loading between the load minimum and the load maximum is a major factor.
©Jürgen Fälchle - stock.adobe.comIn practice:
In tests, for example, Durethan BKV30PH2.0 showed a service life around three times that of a standard polyamide 6 material with 30 percent glass fiber reinforcement at a bending load of 2.75 kN.
In addition to the dynamic behavior, the static-mechanical property profile of the new construction materials has also been improved compared with standard products. The first representatives of the product range are the heat-stabilized compounds Durethan BKV30PH2.0, BKV35PH2.0 and BKV40PH2.0 with glass fiber contents of 30, 35 and 40 percent, as well as Durethan BKV130P, which is reinforced with 30 percent glass fibers and impact-modified.
We also offer two other highly reinforced material variants: Durethan BKV50PH2.0 and Durethan BKV60PH2.0EF. Their short glass fiber content is 50 and 60 percent by weight, respectively. With their high strength and stiffness, these materials are particularly suitable for structural components exposed to dynamic loads, for example in the engine compartment.
Tests have shown that the service life of Durethan BKV50PH2.0 at a peak load of 65 mP is about eight times longer than that of a standard polyamide 6 with the same glass fiber content. Durethan BKV60PH2.0EF also shows about eight times better fatigue strength in the corresponding comparison.
Material fatigue: In Wöhler’s 3-point bending tests, Durethan BKV30PH2.0 withstands over two million load cycles at a bending load of 2.75 kN, while a standard polyamide 6 with 30 percent glass fiber content already fails after around 700,000 cycles.
Durethan BKV60PH2.0EF shows in the HiAnt Fatigue Screening Test a partly several times higher fatigue strength under pulsating load compared to standard material with the same glass fibre content.
Potential applications for the new product series include support structures for electrical and electronic modules in batteries in electric vehicles, engine oil pans, oil filter modules and end caps, engine and chassis mounts, damper pistons and car seat shells. In mechanical engineering, materials are ideal for dynamically stressed components such as gear wheels. However, there is also great potential for use in housing and structural components of power tools such as drills and grinding machines. And for the furniture industry, parts for furniture locking systems can be manufactured from the impact-modified product type.
We support our customers in the development of cyclically highly stressed components from the concept phase through component and tool design to the start of production. For example, we offer numerous component tests: In addition to our servo-hydraulic tensile testing machines for determining Wöhler curves, we also have a shaker pilot plant, which is primarily designed for vibration testing of vehicle applications and covers all common fatigue tests. Our customer service also includes pressure swelling tests on components from the vehicle cooling circuit as well as pressure swing and backfire tests.
Conclusion:
The performance of high-modulus thermoplastics is similar to that of comparable polyamide 66 materials. The mechanical property profile makes polyamide 6-based Durethan Performance an alternative material for polyamide 66 compounds in many cases. As our tests have shown, substitution can often be achieved by product variants with the same glass fiber content, so that no higher material density and thus a higher component weight have to be accepted.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6: Hydrolysis resistant up to 120 °C.
Did you know…
…that PA6 is also used for applications with coolant contact? A common prejudice is that PA66 is the material of choice for water and glycol containing components. Nowadays, the much cheaper PA6 is a good alternative.
©artegorov3@gmail - stock.adobe.comThe resistance of polyamides to coolants is strongly dependent on the operating temperature. The test evidence: Glass fiber-reinforced PA6 GF35 shows very good performance at coolant temperatures of up to 120 °C – and achieves better values than PA66 GF30 in the impact test even after prolonged storage. At permanent coolant temperatures of over 120 °C, however, PA66 exhibits better resistance. Therefore, a PA66 such as our Durethan AKV35HR is recommended in this temperature range.
Coolant temperatures of 80 °C are usually not exceeded in cooling systems for electric vehicles. At these temperatures there is hardly any difference in the aging of PA6 to PA66. We therefore recommend the use of a PA6 grade, especially our special Durethan BKV performance grades.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6: Heat stable – even with long lasting heat.
Did you know…
… that PA66 can be replaced by PA6 even in applications with high ambient temperatures? PA66 is often used because it exhibits excellent heat resistance at temperatures above 200 °C. However, since service temperatures above 200 °C do not even occur in most applications, PA6 can often be used there without any problems. Due to its excellent heat aging behavior compared to PA66, PA6 shows its strengths particularly at temperatures between 150 °C and 200 °C - especially for very long periods of use.
©vrx123 - stock.adobe.comIn practice:
We contrasted a non-heat-stabilized PA6 material with an equally non-heat-stabilized PA66 material and subjected both materials to tensile testing after heat storage to test heat aging behavior. The results: PA66 ages significantly faster than PA6. Even after 3,000 hours, the PA6 still exhibits higher tensile strength than the PA66 after 1,000 hours. Similar results were obtained in the area of flexural strength: This could no longer be determined for PA66 after 3,000 test hours in an ambient temperature of 190 °C - due to excessive degradation of the mechanical properties. The PA6-Durethan BKV30H2.0, on the other hand, still performed very well even after 3,000 hours.
Conclusion:
The common prejudice is still that PA66 is better suited for high-temperature applications than PA6. This prejudice is based on the fact that PA66 has a higher melting point. However, PA6 is shown to have better overall properties at application temperatures below 200 °C.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6 and PBT: dimensional stability ensured.
Did you know…
… that the difference in water absorption between glass fiber reinforced PA66 and PA6 is very small in typical application environments? The comparison is even in favor of PA6 if you add slightly more glass fibers to a PA6 compound.
At the same time, PBT absorbs virtually no water at all. PBT therefore has a natural advantage over PA66 in terms of dimensional stability. It also has very constant mechanical properties that are independent of water absorption.
©Chris - stock.adobe.comWe compared a PA6 material reinforced with glass fibers with a PA66 material and tested both with regard to dimensional stability. In the real application area, the relative humidity of the air turns out to be the same: PA6 achieves similar results to PA66 for flat components. Although water is still absorbed by the material, as it is the case with PA66, the differences in the dimensional change are very small. Significant dimensional changes are recorded in the thickness – dimensional stability is largely guaranteed in the surface.
If additional glass fibers are added, this also reduces the water absorption of the PA6 compound, which has a positive effect on the properties of the material.
With PBT, the results look even better. Because of its chemical structure, PBT only absorbs very small amounts of water – an immense advantage in projects where moisture absorption must not be an obstacle.
LANXESSIt does not always have to be PA66. The dimensional change of components made of PA6 and PA66 due to water absorption is mainly in the thickness direction. In the rarest of cases, this is only occupied with a high tolerance. For this reason, the use of PA6 in the vast majority of cases is possible without problems in dimensional stability. However, PBT is the ideal solution for dimensionally sensitive components.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6 and PBT: PA66 substitutions with minimal effort.
Did you know…
… that in many cases you can switch from PA66 to PA6 and PBT without having to make adjustments to your tools? “Drop-in” and “running change” solutions are possible. For larger components, such as cylinder head covers, PA66, for example, can be very easily substituted by PA6 – with few or no adjustments at all to the tool. And due to its PA66-like shrinkage, PBT can also be used as an alternative in ongoing production – again often even without any tool adaptation.
PA6 has significantly lower shrinkage and distortion values than PA66 – we have proven this in our own application tests. What brings immense advantages right from the start in new projects with new tools due to better tolerance compliance, must be compensated on the existing tool during ongoing production.
The larger the component to be produced, the better the result. Because with the then larger tolerances, the constant and ultimately better shrinkage and distortion values of PA6 are no longer a factor.
When switching from PA66 to PBT, you have even less to worry about when it comes to different shrinkage and warpage values – PBT shrinks in a similar way to PA66. Therefore, it is basically possible to switch from PA66 to PBT during ongoing production. Partly without prior tool adjustments. With polybutylene terephthalates (PBT), you also benefit from significantly better electrical shielding. This makes the material a true all-rounder, especially in the fields of electronics and electrical engineering or e-mobility.
PA6 and PBT are ideal substitutes for PA66. With both materials, you can often replace PA66 with minor tool adjustments even during ongoing production. PBT offers advantages primarily in the E/E area, while PA6 is very well suited as a general substitute due to its very similar material properties. Due to the lower shrinkage and distortion values of PA6, you also benefit from improved compliance with tolerances in new projects.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6: Chemical resistance like PA66.
Did you know…
… that the chemical resistance of PA6 is just as high as that of PA66? No matter whether in acids, bases or solvents – for most applications with chemical contact PA6 can be used just as well as PA66.
©lily - stock.adobe.comIn practice:
PA6 also reveals its strengths in the field of liquids used in the automotive industry. Its resistance to new engine and transmission oils, but also to the more aggressive used oils, is almost identical in PA6 and PA66.
Both plastics also show excellent resistance to diesel and gasoline fuels.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6 and PBT: On par with PA66.
Did you know…
… that differences in mechanical properties between PA6 and PA66 can be easily compensated? By increasing the glass fiber content, properties such as the strength and stiffness of the material can be adapted to the respective requirements.
LANXESSWith the tensile modulus and tensile strength, significantly better results can be achieved with even minor additions of glass fibers in the PA6 compound – whether in dry or humid environments. The values determined are even higher than those of PA66.
In the area of stiffness, a significant increase can also be determined by the addition of glass fiber.
In terms of impact strength, PA6 has a natural advantage over PA66, especially in the conditioned state, even with the same glass fiber content.
PBT absorbs virtually no water. Therefore, the mechanical properties are independent of the condition of the material. Especially in the conditioned state, PBT exhibits significantly higher strength and stiffness compared to PA66.
PA6 achieves better values than PA66 in almost all mechanical properties by adding further glass fiber components. PBT is characterized in particular by its constant mechanical properties.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6: excellent weldability and stability.
Did you know…
…that PA6 is outstandingly weldable? The weld strengths clearly exceed those of PA66.
Weld seams produced by vibration welding have up to 15% higher tensile strength. This can also be seen in the real component. In an experiment, a welded engine intake manifold was manufactured in PA66 and PA6, respectively. The determined burst pressure of the variant made of PA6 GF30 exceeded the value of the variant made of PA66 GF30 by almost 40%.
PA6 can always be welded better than PA66.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6 and Durethan P-Grades – fatigue resistant
like PA66.
Did you know…
… that the fatigue strength of PA6 can be raised to the level of PA66? By adding more glass fiber, we were able to catch up with PA66 – and even outperform it with the properties of our specially developed polyamide 6 performance grades (Durethan BKVP).
©eshma - stock.adobe.comIn practice:
PA66 has shown slight advantages in dynamic strength in the literature so far. Our Wöhler curves show: By adding additional glass fiber components, fatigue strength values similar to those of PA66 can be achieved – especially at high cycle rates and at room temperature
Picture: The red Wöhler curve shows a standard PA66 material and the black one shows a standard PA6 material in comparison with our new P-Grade Durethan BKV30PH2.0 (blue curve).
In tests with high-temperature applications, the results diverge slightly. Among other things, however, the new P grades are used there. At 150 °C, these grades show significantly improved performance in pressure-pulsation resistance.
Conclusion:
PA66 has good fatigue resistance. By using the new Durethan P grades, however, the existing PA6 deficits in this area can be eliminated – both at room temperature and at 150 °C.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.
PA6: Excellent in cycle time.
Did you know…
… that PA6 can achieve almost the same cycle times as PA66? A high proportion of glass fibers, for example, can increase the crystallization rate within the polyamide matrix in PA6.
however, even without glass fiber reinforcement, the cycle time in PA6 is reduced as the size of the component to be produced increases. In other words, the larger the component to be produced, the more marginal the difference.
In the case of thick-walled components, differences in cycle time can also be compensated for by using our EF + XF grades by working at a significantly lower melt temperature. These so-called Easy Flow + Extreme Flow types flow particularly easily and therefore fill the mold cavities just as well at lower melt temperatures. For the E/E range, on the other hand, we recommend the use of PBT, which is the plastic of choice due to its other properties – high tracking resistance, consistently good electrical properties due to its low water absorption.
Would you like to know more? Our development engineers will be happy to answer any questions you may have.