Blowmoulder regulator provides automated quality control

A new automated regulator for blowmoulders can improve polyethylene terephthalate (PET) bottling line efficiency, its manufacturer claims.

Sidel said its Equinox device is the first automatic blow molding regulation system and paves the way for automatic, continuous quality control of the bottle making process.

The Equinox system is built into Sidel's rotary blow molding machines and automatically monitors and corrects bottle quality during production regardless of output rate.

With the advent of increasingly lightweight PET packages, blow molding takes on new importance in the beverage packaging process, Sidel stated.

"In fact, poor bottle quality negatively affects quality on the entire production line and can even lead to total production shutdown," the company said.

"Material distribution holds the key to bottle quality.

Early detection of material distribution problems can help protect an entire production run."

Until now, processors assess quality during production by frequently sampling and measuring bottles in the lab, followed by a manual adjustment if necessary.

In the time it takes to complete this step, production of out-of-tolerance bottles can continue for up to ninety minutes, Sidel stated.

Equinox does not require samples to assess.

The device automatically measures the weight of every bottle base.

The system uses sensor modules that emit infrared light.

The light is absorbed by PET at specific rates depending on mass of material that absorbs infrared radiation.

If the system detects variations from the setpoint weight, it corrects the problem by adjusting the required blow molding parameters.

No machine shutdown is required.

"In most cases, the automatic regulation occurs so quickly that no variation in material distribution exceeds the control limits set for the production mode," Sidel stated.

If the weight is beyond the tolerance limit based on the initial setpoint, then the blow molding machine's control algorithm is automatically triggered, and the operator receives a warning about the problem.

Changes can be made to pre-blow pressure regulate overall production on all stations, and to modify the start of pre-blow adjusts individual stations.

The parameters are automatically adjusted until the weight stabilises and returns to normal, indicating bottle quality and uniformity, Sidel stated.

The adjustments take about two minutes to completely stabilise the process, Sidel estimates.

If Equinox is unable to return the base weight curve to within tolerance limits, it automatically lets the operator know which blow molding station is causing the problem so that the operator can either modify pressure flow or take other corrective measures.