LGF Reinforced Compounds
As design materials, plastics are now well-established in many areas of our lives. To improve strength, thermoplastics are typically reinforced with glass or carbon fibres. Particularly at higher loads such as impact stress or in applications at higher or lower temperatures, the fibre length in short glass fibre reinforced compounds is insufficient, as the polymer matrix begins to soften or become more brittle in such cases. Special compounds reinforced with long glass fibres were developed for this reason.
Long glass fibre compounds have been successfully used in various segments of the industry for several decades. The new product lines AKROMID®, AKROTEK® and AKROLOY® LGF compounds now offer solutions that extend to other segments thanks to the use of base polymers.
Advantages of long glass fibre reinforced compounds:
• Better mechanics at increased temperatures
• Less creep
• Higher working absorption during impact stress
AKROMID® Lite closes this gap between polyamide and polypropylene. Compared to polypropylene, AKROMID® Lite exhibits a better surface quality, improved mechanical properties and higher heat distortion temperature.
The mechanical properties in particular can be improved even further by using long glass fibre compounds. This applies at normal as well as at higher temperatures (see fig. 5 + 6).
Our long glass fibre reinforced Lite compounds also demonstrate significantly increased energy absorption. The Charpy notched impact strength values for long glass fibre reinforced compounds are twice those of short glass fibre reinforced compounds (see fig. 7). This itself is based on the fact that a particular fibre length is required to transfer forces or energy from the polymer matrix to the fibre reinforcement. At room temperature, the residual fibre length of short glass fibre reinforced compounds resulting after injection moulding is generally adequate.
Over the last 10 years, diecast and stamped bent parts have been substituted with engineering plastics especially in the automotive sector as well as in sanitary installations and general mechanical engineering where they have become the most feasible solution.
By blending PA 6.6 with a partially aromatic CoPA (PA 6I/6T), it has been possible to significantly reduce the effect of moisture on the product properties. Whereas a PA 6.6 GF 50 exhibits approx. 25 % drop in rigidity and strength in ambient conditions, a partially aromatic blend exhibits a decline of less than 10 %.
This is particularly evident in stress/strain curves (see fig. 10) at increased temperatures and measurements of the Charpy notched impact strength (see fig. 9). Thus AKROLOY® PA LGF 50 natural (5504) can absorb the same load compared with short glass fibre PA GF 50 natural (2916) at temperatures approx. 40 °C higher. At the same temperature, it is able to withstand significantly higher loads.
To further extend their suitability for high-temperature applications, AKRO-PLASTIC developed long glass fibre compounds with XTC stabilisation. This shielding technology extensively protects the polymer matrix against oxidative degradation at temperatures between approximately 170 °C and 230 °C. This was previously reserved for far more expensive thermoplastics such as PPA or PPS and metals. With AKROMID® C3 LGF 50 5 XTC natural (5574) AKRO-PLASTIC GmbH has developed an innovative compound. Its mechanical properties meet the highest standards, even after storage at temperatures up to 210 °C. After 3,000 h at 210 °C, for example, 80 % of the initial tensile strength is retained (see fig. 12). A further advantage of this stabilisation is the compound is free from halogen-based additives. It is therefore highly recommended for use in electrical applications.
Disclaimer: All specifications and information given on this website are based on our current knowledge and experience. A legally binding promise of certain characteristics or suitability for a concrete individual case cannot be derived from this information. The information supplied here is not intended to release processors and users from the responsibility of carrying out their own tests and inspections in each concrete individual case. AKROMID®, AKROLEN®, AKROLOY®, AKROTEK®, ICX®, PRECITE® and DIA(hr)LOG® are registered trademarks of AKRO-PLASTIC GmbH.