FEATURE High Performance Adhesives

Customizing Standard Formulations to Solve Specific Needs
By Tony Ring, technical director Fielco, LLC, HuntingdonValley, Pa.

For the past decade, most business and industrial literature has emphasized developing customized solutions for specific production needs. Production managers require adhesives that fit their own special manufacturing requirements and would far prefer to use a customized formulation rather than modify a production line to fit the all-too-often artificial limitations of a standard product.

This was not the case a few years ago. Until recently, most manufacturers were content to accept the limits of standard adhesives, and as a result, there was not a great deal of pressure on producers to change formulations. It was quite common for a formulation to remain unchanged for fifteen or twenty years. However, competitive manufacturing pressures have driven the industry to change formulations more quickly, with demands for greater product throughput, shorter cure cycles and much higher performance. Now many standard formulations have less than a three-year market span as ever-improving products replace them.

Custom formulations are forcing these changes. Manufacturers realize that adhesives can perform to their exacting specifications, and they rightly expect producers to make modifications for their needs. Incidentally, these customized products usually become standard in much the same fashion as the pharmaceutical industry's proprietary products become tomorrow's generics - and at that are replaced quickly with improved formulations.

Fielco, LLC saw this trend several years ago and changed its focus to customer demand formulations. While we produce a wide variety of standard products, we let our customers know that these are merely a basis for beginning their own special formulations, crafted to match a specific industrial application. Custom formulations help solve problems, ensure successful manufacturing and put the focus on adhesives as specialty products rather than mere commodities.

In the following three case studies, Fielco, LLC created adhesive solutions for very specific industrial production concerns. We worked closely with the customer to determine needs, test the products thoroughly and create a solution. We also worked with the customer on the next generation of solutions. Due to the confidential nature of our work, not all manufacturers can be identified in the article, but we vouch for the accuracy and specifics in each instance.

Mounting Metal Hubs onto Phenolic Grinding Wheels
The customer called with problems concerning hub mounting on phenolic grinding wheels. They were experiencing a failure rate of up to 5%; the problem centered on low frequency, intermittent adhesion failure during torque tests. We first identified the problem as surface contamination during hub manufacturing that could have been the result of soap, oil or wax film remaining on the hub from the manufacturing process. In these cases, the release agent wasn't being removed effectively. To help determine the specific causes, we recommended the customer check all aspects of the cleaning (rinse) cycle, including a wetting test kit for analyzing the cleaned hubs. With an improved rinse, the customer noticed a dramatic drop in the torque failure rate.

The rinse problem became an opportunity to create an improved product for the customer. We devised a new version of an adhesive that could cut through contaminated surfaces and still generate strong bonds. It also had a very rapid bond strength generation for improved handling, created a tough, vibration and impact resistant bond and featured excellent wetting to cured phenolic resins, abrasive grains and die-cast metal hubs.

To support the new product, Fielco also helped determine the strength requirements for smaller wheel hubs. Next we isolated the cause of the intermittent adhesion problems and helped set up the required QC test, surface wetting, to ensure the hubs were cleaned properly. As an additional service, we supplied adhesive in translucent drums to ensure that the customer's pumps would not run dry. In addition to solving the initial problem, Fielco provided a whole-related range of improvements to meet the customer's specific manufacturing requirements.

Today you can purchase these advantages in Fielco Product Masterweld 5970A/42B, designed specifically for grinding wheel applications. It provides much improved adhesive properties to both pretreated and mill oil contaminated aluminum surfaces as compared to its immediate adhesive predecessor. It also demonstrates higher cohesive strength and improved physical properties than its predecessor, while retaining the expected thermal and mixing characteristics. Custom solutions lead to improved products - all part of the chain of continuous improvement.

Ensuring Product Performance for Safety Tolerances
One Fielco abrasive manufacturer customer experienced difficulty with performance and safety tolerances on a leading product line. The product was prone to develop spot failures with an unknown cause.

Fielco relied on its Sintech mechanical analyzer to measure flexural and tensile strength of the finished product, the material backing and the adhesive itself. From the results, we created a mathematical model of the system and determined that the inconsistencies in the backing caused the problem. The backing was not inherently strong enough to support the abrasive material, given the high speed and pressure required for high performance usage. The backing was bending out of the plane of rotation and showed signs placement in the flap disc bundles to of catastrophic failure.

To resolve the problem, Fielco used the test results to develop a material that acted in a dual fashion. It reinforced the composite backing, giving it far greater flexural and tensile strengths, as seen in the mechanical analysis on the Sintech. Second, the new adhesive material had better flow properties, allowing it to create a more uniform grip. Our customers saw an immediate decrease in their product failure rate, as well as better speed performance of their product. Whereas the product had previously barely met safety standards, the improved product with customized Fielco adhesives more than surpassed safety tolerances.

Other suggestions to the customer focused on optimizing the oven cure cycle, which included a thermocouple placement in the flap disc bundles to determine the heat up rate, as well as to initiate the cure cycle. Our improved adhesive allowed reduction of the cure temperature, resulting in the improvement of overall quality of final product and increased throughput. We quantified the cure cycle by determining the degree of cure of epoxy using Differential Scanning Calorimetry. In addition to the enhanced speed performance as previously mentioned, we were also able to optimize the adhesive discharge temperature to improve product consistency.

All this led to the development of Masterweld 6300, which today notably outperforms its European competition in many areas including:

• Masterweld 6800 has reduced cure cycle times and oven temperatures, allowing for lower heating costs and faster fabrication. Typical cure cycle times are half that of the other product at a lower oven temperature.
• At higher cure temperatures, product degradation takes place, lowering performance and causing discoloration. This problem is eliminated with the new product.
• The new product shows increased green strength, resulting in less flap movement caused by operator handling before the curing takes place.
• Since the Fielco product is a drop-in replacement for the European adhesive, there's no changeover required in pumps or any requirements for flushing residual material away before replacing with the Fielco improvement.

Again, the search for the right solution led Fielco to ask additional questions that, in turn, helped create a superior product for the marketplace.

Building a Setter Brush
The technology for brush manufacture constantly evolves. For example, Indusco, a leading manufacturer of industrial brushes, turned to Fielco several years ago for specific high technology solutions to their adhesives problems. As Indusco's Tim Enchelmaier explained, "Our brushes need to meet our customers' exacting needs. We change our brushes to match customer requirements for solvents, application materials and specific industrial conditions.

"Several years ago we needed to develop an epoxy for our brushes that gave a strong but flexible bond. Prior to this we had been using a phenolic bond, which has some significant limitations. Phenolic products can lack flexibility and can also cause clumps or rocks in the brush, which increases materials waste. We turned to Fielco for a high technology product that would give our brushes a mechanical (epoxy-based) bond with great flexibility without the drawbacks of phenolics."

Fielco created a specific two-part epoxy product, MG 1167 A/B, to meet Indusco's need. This product had excellent adhesive properties and was notably resistant to decay from solvents and other manufacturing chemicals. It was a customized product for a specific requirement.

But Fielco knew that Indusco would want an improved version of MG 1167 A/B. Indusco was satisfied with MG 1167 A/B, but we saw some opportunities for improvement. We worked directly with Indusco's team to develop MG 1168 A/B, which had several additional benefits over its predecessor. First, it gave improved adhesion to various metal mandrels, while retaining the beneficial properties of its predecessor. Second, and most important, it proved to be far less toxic and better for Indusco's manufacturing operation.

Tim Enchelmaier noted, "Our employees' safety is very important to us. The dramatically reduced toxicity of MG 1168 A/B helped us safeguard our employees' health and also improved productivity. When you run a family concern, you have an ongoing commitment to your organization and that means protecting your workers' health and maintaining a safe working environment."

Fielco worked closely with Indusco to ensure that the products were used effectively. Representatives from Fielco helped train Indusco's workers in the proper handling and safety requirements for the adhesives, including hygienic practices, ventilation, use of protective gloves and eye protection. The commitment to quality continued through the actual manufacturing process as Fielco assisted Indusco in setting up a meter mix dispenser (Ashby-Cross) for MG 1168 A/B. Not only did Fielco want to develop a superior product, they were also committed to Indusco's ongoing manufacturing success.

The net results? The new materials had a dramatic effect on productivity. After using MG 1167 A/B and MG 1168 A/B, Indusco reduced its rejection rate on related brush lines from 15% to less than 1%. These are savings that help slash materials waste and the associated labor costs from unnecessary materials handing.

In all three examples, teamwork between Fielco, LLC and their customers made these improvements possible. By focusing on improvements, all partners develop superior products and everyone benefits. Today's specialty innovative solutions will become tomorrow's expectations.