Transient Entanglement Disentanglement Kinetics in Deep Draw Thermoforming under Multiaxial Strain Gradients
Matching plug speed to polymer disentanglement kinetics prevents corner thinning and optimizes wall thickness in deep draw thermoforming.
Servo Plug Assist
Meaning
A mechanical system driven by a precision servo motor controls the movement of a plug used to pre-stretch heated plastic sheets during thermoforming. This configuration is a servo plug assist and replaces older pneumatic cylinders with fully programmable electric drives. It allows the operator to control the speed and depth of the plug penetration into the mould cavity.
Process Control
Achieving consistent wall thickness in deep-drawn thermoformed parts depends on the precise movement of the plug. The servo plug assist adjusts its speed profile dynamically to match the stretching behavior of the polymer sheet. This capability prevents thin spots and punctures that often occur when using pneumatic systems.
It enables the repeat production of complex parts with tight tolerances.
Material Efficiency
Reducing the starting sheet thickness is possible when the polymer is distributed evenly during the forming cycle. By using a servo plug assist, processors can down-gauge the sheet without compromising the strength of the final product. This reduction in material use lowers the overall cost per part and minimizes trim scrap.
It improves the economics of high-volume packaging runs by allowing the use of multi-cavity moulds that require uniform sheet stretching.
Operational Variable
Configuring the acceleration and deceleration of the plug is performed through the machine interface. The required profile varies based on the resin type and part depth. This stability reduces reject rates during long runs.