FRP: Consistent and Continuous Catalyst Supply Is Key

Greg Van Gansen / ATFD Product Marketing Specialist - Graco

Consistent cure, high-quality parts and end products depend on a continuous catalyst flow rate. One of the largest problems faced by Fibre Reinforced Plastic (FRP) spray users is a reduction in catalyst supply. If there is insufficient catalyst in the mix, soft spots can develop, leading to costly rework and potential quality issues. In this respect, the presence of catalyst in the polyester is very important. Graco, with its own designed FRP gel coat and trim systems, ensures that the catalyst is continuously available and in the required proportion. This system, manufactured with proven Graco components in the industry, provides a technologically advanced, robust and long-lasting solution. With Graco's FRP gel coat and trim systems, consistent proportioning is guaranteed for consistent cure, and as a result, higher quality parts and end products are produced. In fact, the system is optimized for proportioning stability.

How Is This Achieved?

Graco's consistent catalyst supply is backed by three main elements. First, Graco's air motor reduces transition time to a minimum, ensuring continuous material pressure on the catalyst. As a result, negligible pulsation at spray pressure and well-mixed resin are obtained. The advantage of constant spray pressure is a consistent spray pattern. The transition is enabled by check valves triggered by the piston reaching the end of the air motor. This triggers rapid transfer of air pressure from one side of the air motor to the other, thus achieving rapid motor transition. Additionally, Graco's air motor is perfectly balanced; that is, the material pressure in the motor is equal on upstroke and downstroke. As a result, a consistent spray pattern is again achieved. Consistent and high-quality spray pattern makes it easier for the user to control the spray pattern. It has higher transfer efficiency and consequently provides consistent quality end products with high material savings (up to 40%). The second important feature is unique packing material that provides more consistent catalyst flow by minimizing friction and increasing transition speed. The third is the use of expandable hoses for the resin. These reduce pulsation during transition and allow smoother volume to pass through the catalyst pump. The overall result is smooth, consistent and pulse-free catalyst supply. Stable catalyst pressure provides continuous catalyst flow and minimizes the likelihood of wet spots or uncatalyzed areas in the application. Graco's gel coat and FRP system is suitable for use in boats, healthcare facilities, pools, trailers and many other areas.

Optimal Spray Pattern

Droplets leaking onto the floor, wall or worker's clothing is clearly wasted material. Graco's special Air-Assisted Containment (AAC) has been developed to ensure that the maximum amount of material is delivered to the desired location: where you are spraying. The AAC creates a spray pattern where droplets fly into the mold at very low pressure. Low velocity or "particle velocity" causes very little turbulence or irregularity when material reaches the mold. Spray guns from other manufacturers have high "particle velocity", causing very high turbulence during the application process. Turbulence or excessive atomization causes air entrapment; this can lead to void formation.

Long-Lasting and Easy Maintenance

Graco designed the FRP system to be easily maintained with limited tools and expertise. Its durability and robustness reduce production costs and increase efficiency on the production line. Graco achieved these benefits through longer-lasting seals and planned maintenance at longer intervals. Easy maintenance of the FRP unit is achieved by eliminating the need for an expansion tank, which would reduce repair parts, solvent, and resin used for filling.

Redesigned Trimmer

At just 1 kg in weight, the Graco RS Trimmer is 40% lighter than other trimmers on the market. The revolutionary air motor generates high torque and speeds, delivering high glass processing volume. The product is designed to offer fast blade change in less than 30 seconds; lightning quick compared to conventional trimmers that require about 15 minutes for blade change. Additionally, its magnetized holder allows easy replacement of individual blades, or even all of them with just one blade. Another important feature is that the tension of the trimmer head anvil can be changed while working without removing the guard. The anvil and trimmer head sprocket in the Graco RS Trimmer are mounted on a spring-loaded sliding mechanism. The tension adjustment button determines how much force is applied between the anvil and trimmer head. Performance can be improved by making small adjustments to the tension button on the trimmer. The Graco RS Gun and Trimmer optimize weight distribution to achieve a low center of gravity and balanced gun. The trimmer angle proportional to the spray pattern ensures that trimmed fiberglass fibers are evenly distributed across the spray pattern. Reduced cost for filled resins (elevated) A1 Fiberglas uses various fiberglass mold and application processes. The Hastings, Nebraska facility, which produces fiberglass parts for caravans, buses, medical equipment and amusement park rides, was seeking new ways to increase work efficiency. Their main objectives were to reduce downtime by reducing the number of pump overhauls required when using filled resin and to establish a schedule for overhauls by implementing preventive maintenance programs. This production environment proved to be an ideal test area for the Graco FRP System. A1 created a Graco FRP trimming system featuring DataTrak™ Control and Graco RS Chop Gun™ capabilities. A1 sprays approximately 453 kg (110 gallons) of resin daily, five days a week. According to feedback from users, pump seals now last longer and require less overhaul than previous competing pumps. DataTrak, which monitors resin usage and tracks cycles, provided the maintenance team with the ability to monitor system output and plan overhauls in advance. Furthermore, the absence of an expansion nozzle makes the system safer and more maintenance-friendly.

Boat Builders Increase Efficiency

Legend Boats LTD, a company that manufactures specialized fiberglass fishing boats, operates five days a week with very high output. Although Legend Boats was satisfied with the results from their current guns, they were seeking new ways to increase efficiency. Graco distributor Fluid Air Products suggested they try the new Graco FRP trimming system. This brought immediate success. The high-output trimmer and external anvil adjustment reduced downtime, allowing the company to increase productivity. The easily cleaned front head helped Legend Boats reduce acetone usage by several gallons per day, saving money. The external mixing gun provided a better spray pattern and more consistent cure across all parts. The output of the new gun was also well received. With one fiber wick on the Graco RS Trimming Gun, the output was nearly the same as two fiber applications on the previous trimmer. As a result, it was concluded that the trimming gun was very user-friendly with minimal maintenance.

Easy Transition from Wetting to Trimming

Although satisfied with GlasCraft® equipment and GlasCraft Formula Distribution Gun products, economic conditions drove Carlson Engineered Composites to seek ways to increase production efficiency. The transition from wetting to trimming consumed significant time during blade change and fiber trim adjustments. Due to a recent workforce reduction, the company needed to accomplish more by increasing production speed and reducing production downtime. Graco distributor Progress Plastics suggested that Carlson use the new Graco FRP trimming system to gain efficiency. With this new system, Carlson Engineered Composites witnessed improvements in a short time. The gun's dual-trigger feature allowed users to transition from wetting to trimming without physically shutting off fiber trim. This was particularly advantageous when the user wanted to add more resin after applying fiberglass. The gun's blade cartridge made blade changes easier and safer by molding the blades directly into the cartridge. Users no longer needed a tool to remove blades or had to touch each blade individually. Carlson liked the gun design because the tension between the blade and anvil could be easily adjusted without removing the guard. Carlson was convinced that the Graco FRP trimming system contributed to increased production efficiency and overall safety. Cristiano Giancola / Technical Training Manager - Graco