Given the expense of stainless steel tanks, discarding the tanks after each use was not a feasible option. A less expensive alternative had to be found. The company turned to Terracon and, in just four weeks, they came up with a solution: custom-configured cone bottom plastic tanks that met all of the manufacturer’s requirements and saved the company thousands of dollars a year. The company now orders 5-10 of these systems several times each quarter.
To design the solution, the Terracon team met with the production team to detail manufacturing requirements in order to design an alternative solution using 600L plastic tanks and the appropriate fittings and configurations.
As it turns out, in the manufacturing process, materials would flow from a feeder to the tank; therefore, Terracon needed to configure the top of the tank to mate with the existing equipment. To solve the problem, the team developed an application-specific top collar with a 15-inch opening to allow ingredients to flow in, and mixers to be inserted. The team then welded the collar to the top dome of the tank. It should be noted that all of connections and fitting transitions comply with the ASME (American Society of Mechanical Engineers) BPE (BioProcessing Equipment)-2009 Standard.
In addition to integrating with the existing manufacturing process components, a critical requirement of the plastic tank system design was to conform to aseptic manufacturing practices. To ensure elimination of dead leg and to promote complete drainage, the original tank—molded with a 45-degree slope and a small 6- to 7-inch-diameter flat surface at the bottom—was modified to eliminate the flat, and continue the cone slope all the way to the bottom outlet port. The design achieves two important objectives: complete drainage and improved mixing efficiency. The solution also includes a sanitary outlet port that links up to a recirculation and dispensing loop through which the operator withdraws finished product.
The final aspect of the complete plastic tank solution was portability of the solution. To promote ease of movement and workplace safety, the tanks, weighing about 75 pounds each when empty, were equipped with handles on each side—an easy fix.
What started out as the need to replace stainless steel tanks that compromised aseptic manufacturing requirements turned into a manufacturing solution and a long-standing relationship that has identified and overcome more of the customer's processing challenges than originally defined, including aseptic transitioning with the feeder and mixers, improved ease of carrying and moving the tanks, and ports to enable in-process sampling while providing smooth-flowing full-drainage vessels as defined in the initial specification. The customer is pleased because the single-use system solved a serious problem in just four weeks, and the solution not only meets its specific manufacturing requirements, but delivered significant savings as well.
Single-Use Mixing Tank Product Line Brought to Market
One of the most expensive aspects of manufacturing operations has traditionally been the cleaning and validation process required by the U.S. Food and Drug Administration (FDA). When manufacturers need to change production from one batch to another batch or from one product to another product, everything needs to be completely cleaned and then validated. Moreover, the validation process requires these companies to undertake extensive and time-consuming documentation.
Single-use systems, of course, solve this problem—and when a global pharmaceutical equipment manufacturer identified a market opportunity for large-scale (up to 500L) single-use mixing capabilities, the company decided to team with Terracon Corporation to design and deliver a complete, state-of-the-art solution that would cut costs and speed production. Primary components of the single-use system would be 3-D mixing bags validated and certified to be clean and sterile and a cylindrical open-top cone bottom (COC) tank.
Initially, the two companies met weekly at Terracon’s facilities, detailing requirements and discussing ideas and potential solutions. The team tackled one problem at a time. One of the key challenges was how to place the heavy motor in a position to ensure it engages and aligns reliably with the internal mixing elements without tearing the mixing bag; the team solved this issue by developing a sturdy hinged platform that incorporates the motor and swings up and down in a precise fashion to maintain the integrity of the bag.
Another key requirement was to design a way for the operator to easily replace one single-use mixing bag with another without slowing the production process. They solved this problem by designing a hinged door in the tank sidewall to enable users to reach in to install bags. A transparent window in the door allows visual confirmation of mixing activity. A small cut-out at the bottom of the door also enables operators to access product for sampling. In addition, the carrier comprises custom accessories and features including flared legs to prevent tipping and a base with fully locking casters for mobility, security, and stability.