Manufacturing and testing of long basalt fiber reinforced thermoplastic matrix composites

Abstract

In this work, long basalt fiber reinforced composites were investigated and compared with short basalt fiber reinforced compounds. The results show that long fiber reinforced thermoplastic composites are particularly advantageous in the respects of dynamic mechanical properties and injection molding shrinkage. The fiber orientation in long basalt fiber reinforced products fundamentally differs from short basalt fiber reinforced ones. This results in more isotropic molding shrinkage in case of long basalt fiber reinforced composites. The main advantage of the used long fiber thermoplastic technology is that the special long fiber reinforced pellet can be processed by most conventional injection molding machines. During extrusion compounding the fibers in the compound containing 30 wt% fibers are fragmented to an average length of 0.48 mm (typical of short fiber reinforced thermoplastic compounds), this length decreases further during injection molding to 0.20 mm. Contrarily using long fiber reinforced pellets and cautious injection molding parameters, an average fiber length of 1.8 mm can be achieved with a conventional injection molding machine, which increased the average length/diameter ratio from 14 to 130. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers

Effective mechanical and transport properties of polysiloxane matrix based composites

“…Similar results for carbon textile reinforcements bonded to an epoxy resin were reported in [4] showing an increasing trend in impact resistance with increasing specimen thickness. Note that for short and long basalt fiber reinforced thermoplastic matrix laminates the Charpy impact strength was found in the range of 48-75 kJ/m 2 [3] comparable to the values obtained for glass fabric based systems. …”

“…This is not a trivial task and requires extensive image analysis to acquire basic geometrical data and consequently well defined experimentally measurable data to corroborate the numerical predictions. The latter issue considers effective electric conductivities already exploited to some extent in the combined numerical-experimental study of unidirectional basalt [3] and carbon-textile [6] polysiloxane matrix based composites. Detailed analysis of SEPUC goes, however, beyond the present scope.…”

“…In the present study, specimens having in-plane dimensions 60 × 60 mm were subjected to impact of a falling weight, see [3] for instrumentation details. The material is typically quantified by calculating the penetration energy written as…”

“…In this framework, the impact damage resistance is examined in the light of the type of reinforcement, the number of reinforcement layers and processing temperature. To that end, the standard Charpy and falling weight [3] tests were performed considering six and eight layer polysiloxane matrix based composite reinforced by carbon, basalt and glass plain weave fabrics and manufactured at three different processing temperatures (200…”

“…Six specimens were tested for each direction and laminate thickness (6 and 8 layers). The energy E c absorbed by the specimen was recorded and the Charpy impact strength α c was calculated as [3] …”