6.1 Introduction

In this chapter the desisgn and the different relationship between runner secments are studied herein. The first step in runner design is to diveded the mold into several logical sections. The volume of every section has to be calculated. Then the design has to ensure that the gate velocity and the filling time of every section to be as recommend by experimental results. At this stage there is no known relaible theory/model known to the author to predits these values. The values are based havily on semi-rilaible experiments. The Backword Design is discuused. The reader with knolege in electrical enginnering (electrical circtes) will notice in some similarities. However, hydralulic circuts are more complex. Part of the expressions are simplified to have analytical expressions. Yet, in actuality all the terms should be taken into considerations and commercial software such DiePerfect should be used.