Mechanical design improvements greatly enhanced success rate during primary de-bagging for double-bag products.
Making several practical alterations to the automated de-bagging process for aseptic manufacturing could significantly increase overall reliability, research suggests.
In their study, Schouterden et al. optimised the first de-bagging step of bag-in-bag products of an existing de-bagger setup, reporting an overall success rate of 89 percent, increasing from 30 percent.
In these automated systems, double-bagged products are transferred from a non-sterile to a highly sterile environment. The current techniques has a high failure rate, mainly due to damaged packaging resulting from the “irregular nature” of the bags. This issue is compounded by the strict guidelines required for de-bagging in aseptic environments. Consequently, the initial de-bagging step results in “significant product loss and production downtime”, Schouterden et al. wrote.
As such, they sought to address the current challenges by optimised the process, utilising a plastic, box-shaped container of two halves fitted within a double bag.
The improvements comprised of testing practical mechanical adjustments and force-based evaluations in three stages. Additionally, a final combined process was evaluated in a larger-scale validation assessed across multiple product batches.
optimisations improved the general success rate from 30 to 60 percent"
Based on outcomes from the first stage, the authors concluded that rear bag clamping should be improved. This would “allow higher push-out forces and the force compensation should be eliminated to avoid the potential wrinkling and bunching up of the outer bag”. Testing showed these optimisations improved the general success rate from 30 to 60 percent.
The second stage improvements showed that “lowering the top-mounted guide rails and enlarging their contact surface” helped reduce the chance of damaging the outer bag during the push-out process.
In the third stage, the team assessed less directly observable parameters using push-out force measurements, push-out failure rates, and statistical analysis. “While several comparisons did not reach conventional significance thresholds, consistent trends toward lower push-out forces and reduced failure rates were observed when releasing the front suction clamp during push-out and when actively driving the pusher bar rotation”.
Specifically, to improve the design of de-bagging processes the authors recommended that:
- all contact surfaces with the product should maximise their contact area to distribute the load and avoid all kinds of edges in contact with the product
- guide rails should minimise the product’s freedom of movement and preferably only allow movement in the wanted orientations
- all clamping of the bag should be fixated in a way that the formation of wrinkles or the bunching up of excess bag is avoided
- an actively driven push bar can be beneficial if the rotational velocity is properly tuned.
The paper was published in Journal of Pharmaceutical Innovation.
