Hardener composition role on mechanical properties of polyester and lycal resin

Polyester and lycal resin are common used plastic as matrix of composite. Hand lay-up is also easiest and cheap method to produce composite. However this method is still not effective to produces a free porosity composite. Vaccuum infusion in which air is mainly force-sucked out of die then resin introduce on the die, could minimized existence of the porosities. It is effectively used on resin with gel time of 1 to 1.5 hours, in which both of the resin are fit with. Gel time is a function of hardener amount, and different amount of hardener may results different properties. This study investigated influence of hardener ratio to resin and hardener prior to vacuum infusion, towards tensile and compressive strength of the resin. The ratio between polyester and hardener was 10:0.5, 10:1, and 10:1.5. And the ratio between lycal and hardener was 3:0.5, 3:1, and 3:1.5. Density test showed that increasing of hardener amount had slightly reduced density of both resin. Tensile test was conducted according to ASTM D638, and Compressive test was with ASTM D695. It was revealed that a highest tensile strength of 43 MPa at lycal ratio of 3:1, and 39 MPa at polyester ratio of 3:0.5. Other, it resulted a highest compressive strength of 71 MPa at lycal ratio of 3:1.5, of 48 MPa at polyester ratio of 10:1. The lycal ratio of 3:1 provided compressive strength of 68 MPa, a comparable strength with the highest. These information might usefull to prepare technical composition of resin and hardener, to optimize the reinforced plastic composite.