Cavity Pressure Telemetry Fundamentals in Fast-Cycle Moulding
Cavity pressure telemetry decouples fast-cycle moulding from resin viscosity shifts by driving switchover directly from real-time in-cavity melt fronts.
Multi Cavity Flow Balance
Meaning
Flow characteristics determine the relative timing of melt reaching the end of each cavity. Achieving multi cavity flow balance ensures that each part in a large mould has identical dimensions and physical properties. If one cavity fills before others, it will pack more densely and potentially warp.
Balancing is achieved by adjusting runner diameters or gate sizes.
Melt Distribution
Equal pressure must be delivered to every gate for the cavities to fill simultaneously. Geometrically balanced runners are the primary method for achieving this state. In an unbalanced layout, the plastic travels different distances to reach each cavity.
Quality Variation
Differences in filling time lead to variations in part weight and strength. A mould with poor multi cavity flow balance will produce parts with different levels of internal stress. This often results in a high scrap rate because some parts will fail to meet the dimensional specifications.
Tooling Adjustment
Steel is removed from the runners or gates to fine tune the flow. Technicians use short shot studies to identify which cavities are filling slowly. By slightly enlarging the gate of a slow cavity, the flow resistance is reduced.
This mechanical tuning is a standard part of the mould validation process.