This paper presented a study that revealed the severity of the filling imbalance for thermosetting materials in conventional geometrically balanced runner systems. The paper also presented a solution to the filling imbalance. The imbalance in the tested production mold was found to be almost 18% (see figure 10). This imbalance could potentially affect cure time, degree of curing and ultimately the properties of the final product. The solution was to add a melt conditioner that rotates the laminates of the melt. This virtually eliminated the side-to-side shear variation, provided for uniform material properties to each cavity, and thereby balanced the mold-filling pattern. In addition, a uniform balance of the curing properties and the mechanical properties of the molded part in tools containing geometrically balanced runner systems may be obtained using this method (7).
展开▼
