Experimental analysis of resin injection pultrusion

Pultrusion is a process, which continuously produces high performance composites with low cost and high productivity. This study focuses on the pulling force, effective mass diffusivity, the void formation and removal, and blister formation. The goal is to develop high-speed pultrusion.; Pulling force is the summation of force resistances inside a die, which is complicated because a reactive resins experience liquid, gel, and solid stages along with fiber reinforcements. Two methods are used to study the pulling force, i.e., additional mat and different die length methods. Results show that the downstream part of die has no contribution to the pulling force.; Effective mass diffusivity in composite field is an important parameter in studying thermal-hygral effect of composites and the void diffusion during manufacturing. In this study, analytical models are developed to predict the effective mass diffusivity in rectangular and hexagonal arrays. The models agree reasonably well with the experimental data and other analytical models. The models agree very well when porosity is low. A weight factor is used to compensate for the error caused by assumptions. The modified models agree very well with the experimental data and other models in the whole range of porosity.; Fiber wetting is still a major concern in liquid composite molding such as in the resin injection pultrusion and resin transfer molding (RTM). This study focuses the cylindrical void formation and removal during processing. Fiber ring structure is proposed, which may cause the cylindrical void formation. A model of the cylindrical void diffusion is developed to understand the cylindrical void removal.; The blister is a major hurdle hindering productivity. The objective of this study is to investigate the mechanism of blister formation and the effect of process variables such as die temperature, line speed, die length, and the geometry of composite part on the blister formation. Process windows are developed based on the blister for different thickness. The effect of pulling speed on the mechanical properties is also examined.