How could better control of a servo valve be used to improve blow moulding production?

An extrusion blow mounding system for controlling parison wall thickness could contain a closed loop control system monitoring the actual position of a movable die member and feedback signal from an automatic weighing system for the product.

This information can be used to set a desired position signal from the wall thickness controller to an electro-hydraulic servo-valve controlling the position of the movable die member that is providing the desired width of the die gap. The process ensures the weight of the final product is within a narrow weight range resulting in improved product consistency and quality. It also enables the total quantity of moulding material used in moulding of the product to be decreased.