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Tag Archive: Seal Aluminum Die Castings

1. Case Study: How One Company Overcame Their Casting Porosity Challenge

   January 8, 2019 3:22 pm Leave a Comment

   Manufacturing activities are being shaped to an increasing degree by the demands of consumer taste. Consumer’s expectations of quality and performance define product design, which further determines the requirements of the supply chain. This is a landscape that rewards suppliers who identify opportunities to adapt to the changing circumstances. One example is a vacuum impregnation service center that seals a variety of aluminum die castings for various automotive and industrial OEMs, Tier 1, and 2 suppliers.

   The Challenge

   The company primarily uses in-house batch impregnation systems to process the die castings. The batch systems aggregate various parts and process them in large batches. Despite being well versed in vacuum impregnation, the company could not reliably process the high value and complex castings due to the limitations of their batch systems. The company realized that the following challenges needed to be answered:

   • Contamination-Cured sealant remained in the through and blind tape holes.
   • Handling Damage-Despite being sealed, some parts were scrapped due to damage to machined features from handling in the batch system (Figure 1).
   • Floor Space-The batch systems consumed a lot of floor space, which prohibited efficient work flow and increased Work-In-Process (WIP).

   

   Figure 1: Despite being sealed, some parts were scrapped due to damage to machined features from handling in the batch system.

   The Solution

   To meet their customer’s quality and production requirements, the company realized that they needed to install an effective impregnation process in their manufacturing environment. Working with Godfrey & Wing, the company laid out their vision. Godfrey & Wing responded with its Continuous Flow impregnation (CFi) system (Figure 2). The system would be customized to answer the customer’s challenges.

   

   Figure 2: The CFi system uses Dry Vacuum and Pressure (DVP) and recoverable sealants to be the most effective impregnation process in the world. Its use of automation means it seals porosity at a higher rate, in a shorter cycle time and with minimal labor.

   The CFi uses the patented Dry Vacuum and Pressure (DVP) process, and 95-1000A or 95-1000AA recoverable sealant. Demonstrated to be the most effective vacuum impregnation process in the world, the CFi with the DVP process incorporates a fast, deep vacuum to evacuate the air from the porosity. Then after moving sealant to the part, the system applies high pressure to allow the sealant to thoroughly penetrate deep in the casting walls.

   The castings are in custom designed fixtures to maximize the amount of castings per cycle, flush sealant from blind holes, and protect critical machined features. The fixtures are delivered to the CFi via a conveyor; the CFI takes over and automatically moves the fixtures through the process. This allows the castings to be processed within the fixture without damage (Figure 3).

   

   Figure 3: The fixtures are delivered to the CFi via a conveyor; the CFI takes over and automatically moves the fixtures through the process. This allows the castings to be processed within the fixture without damage.

   The CFi system is fully self-contained for quality. The robot and PLC would work together to ensure that fixtures do not leave the system until meeting all of the pre-determined conditions. If acceptable, then the robot will move the fixtures from the CFi to the next process.

   The customer relayed to the Godfrey & Wing engineering team where they wanted to place the system on the floor. With this knowledge, the engineering team designed the layout and maintenance access to be integrated with the existing manufacturing flow.

   

   The Results

   The data clearly shows that the Godfrey & Wing CFi system achieved all of the customer’s goals. The results included:

   • Improve Casting Recovery-Scrap from porosity has been virtually eradicated with the CFi delivering a First Time Through (FFT) rating of near 100%. Historically, batch systems recover approximately 85% of castings. The CFi represents nearly a 15 point improvement over the previous impregnation methods.
   • Eliminate Contamination Handling Damage-The CFi has completely eliminated damage and sealant contamination and runs at 0 PPM. The part flow and fixture design flush sealant from the through and blind tap holes and machined features. This ensures that sealant residue is not on any critical features.
   • Reduce Floor Space-The CFi processes 40 cycles per hour, and requires 800 square feet with no infrastructure changes. The system maximizes production, eliminates WIP, and reduces floor space.

   In Summary

   This company found great value in searching for a new way to meet their customer’s ever-changing quality and performance demands. Godfrey & Wing’s automated CFi system is the only system that can meet the stringent demands. The CFi demonstrates that manufacturers can take control of the porosity sealing step and integrate vacuum impregnation into their production flow, to ensure product quality and productivity.

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2. Case Study: Aluminum Casting Porosity Forces the Need for Vacuum Impregnation

   February 1, 2018 4:26 pm Leave a Comment

   One of the largest aluminum casting facilities in United States produces engine blocks and transmission cases for an automotive OEM. This facility supplies the vast majority of powertrain castings in support of the OEM’s assembly operation throughout North America.

   The Challenge

   The casting standards and aluminum characteristics forced the need for vacuum impregnation. The program was launched with a vendor that utilized a Dry Vacuum (DV) process in an older batch style vacuum impregnation system. Unfortunately, the system and process could not meet the quality demands of the foundry or the OEM.

   The main challenges were:

   • Poor recovery– 14% of the parts still leaked after impregnation.
   • Contamination– Cured (solid) sealant remained in through and blind tapped holes.
   • Part Damage– Damage to machined features from handling and the impregnation process.

   These challenges caused missed shipments, quality alerts and increased rework costs. A better process was needed to deliver a higher quality parts.

   The Solution

   Based on the customer’s requirements and production quantities, Godfrey & Wing proposed the Dry Vacuum and Pressure (DVP) Continuous Flow vacuum impregnation (CFI) process for the customer’s parts.  The CFi seals high volumes of parts in a short cycle time with minimal labor. The system uses a recoverable sealant, maintaining the sealant in is original and purest state, which allows for repeated use.

   

   Godfrey & Wing’s solution was designed to address each of the customers concerns: 

   • Dry Vacuum and Pressure (DVP) process– Godfrey & Wing’s data indicated a meaningful improvement in recovery would be found using the DVP process. The previous vendor used a vacuum only process.
   • Single fixture part flow- Using single part flow systems allows parts to be fixture in a manner that promotes repeatability and consistent processing. The previous impregnation vendor stacked parts side by side in a random manner in large steel baskets leading to multiple failure modes. 
   • Automation– Material handling would be done with a robot instead of manual labor. This insures all parts are processed correctly and in sequence.  The previous vendor’s batch system is manually controlled where the large baskets could be packed or processed incorrectly.  

   Having never qualified the DVP process, the customer ran a sample to determine how much more effective it would perform compared to its existing DV process. The results clearly showed the DVP process surpassed the existing sealing results:

   • 100% part recovery– The customer’s part recovery rate increased to 100% with the DVP. This was a 14% improvement over the average rate with their existing process.
   • 0% part contamination– Using the DVP process, the customer’s rate of part contamination dropped to virtually zero.
   • 0% part damage– The customer experienced no part damage with the DVP process.

   Impressed with the results, the customer moved production to Godfrey & Wing.

   The Results

   During the first year of production, the CFI impregnated over 16,000 parts. The First Time Through (FTT) rate remained at 100% without any contamination or damage. The impregnation process continues to achieve 100% recovery without any contamination or damage. The process seals the parts at 150 cc.

   

   Godfrey & Wing’s CFi with the DVP process solution answered the following challenges:

   • Improve Recovery-The DVP process pushes the sealant deep into the micro porosity, which delivers near 100% recovery in a single cycle. The process thus delivers improved sealing efficiency.
   • Eliminate Contamination-Instead of packing the parts in a basket; the parts are placed in fixtures that hold either one or two parts. This allows excess sealant is effectively washed from the part during the cycle.
   • Eliminate Part Damage-The CFI system is fully robotic; the attendant interacts with the system through the HMI panel. The system’s robotic arm moves the castings between stations, which allows for a shorter cycle time and eliminates operator errors.

   In Summary

   As companies continue their search for ways to reduce costs and increase quality, it will be necessary to challenge the status quo. This company realized that the DV recovery rates were no longer valid for today. With Godfrey & Wing’s technology and processes, this company maximized casting recovery, reduced costs and improved quality. 

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