Proven Performance: A Deep Dive into DELTA DUCON'S SPIRA/flo® Pipe's Superiority in Plastic Pellet Conveying

In the plastics industry, maintaining the quality and efficiency of raw materials, specifically plastic pellets, is essential. The journey of these pellets through pneumatic conveying systems often presents a significant challenge: the creation of "angel hair" and fines. This unwanted byproduct, caused by friction, shearing, and impact within the pipeline, can lead to product degradation, increased maintenance needs, and noticeable operational inefficiencies, directly impacting profitability and the quality of the final product.

At Delta Ducon, with over a century of innovation in bulk material handling, we've long understood the specialized requirements of the plastics sector. Our expertise extends beyond traditional abrasive materials to include the unique characteristics of polymer pellets. Our solution to the angel hair problem is SPIRA/flo® Pipe, a unique, pressed groove pipe carefully designed to significantly reduce the formation of angel hair and fines. The effectiveness of SPIRA/flo® isn't just a claim from lab tests; it's a history of proven, real-world performance, powerfully shown by a key competitive test conducted by a leading polyethylene pellet producer.

This article revisits the compelling findings of that original test report, transcribed directly from the original document, to explain why DELTA DUCON’S SPIRA/flo® has been the preferred choice for this major producer for over 45 years, and how its innovative design continues to set the standard for optimizing plastic pellet conveying in the most demanding environments.

The Competitive Test: Setting the Standard for Angel Hair Reduction in Plastics

A prominent polyethylene pellet producer initiated a thorough competitive test. The goal was to evaluate various pipe interior treatments for their ability to reduce angel hair formation during pneumatic conveying. This was a critical effort for any plastics manufacturer, as angel hair can clog screens, foul processing equipment, and ultimately lower the quality of the finished plastic product. The aim was clear: find a pipe that could maintain excellent product quality by minimizing these unwanted fibrous strands of plastic.

The test program directly compared four different types of pipes:

• Smooth wall pipe

• Dimpled/Shot peened pipe

• Cut groove pipe

• Delta Ducon's SPIRA/flo® Pipe 

  
  

The tests were carefully conducted at the producer's dedicated pneumatic conveying test facility. Conditions were precisely standardized to ensure a fair and consistent comparison across all pipe types, with the only variable being the pipe's internal surface. TR635 pellets were used for all the tests. The test unit operated as a push-pull system, allowing for continuous operation over a long enough period to reliably produce angel hair under controlled conditions.

The setup included about 225 equivalent feet of 2-inch pipe. This consisted of 50-foot straight sections and four 90-degree bends. To further simulate real-world conditions that can worsen angel hair, two of the bends were heat-taped, and all of the pipe was insulated with a 1-inch layer of fiberglass. Each test run lasted exactly five hours. To ensure significant angel hair production, especially given the cold weather during the test period, high conveying velocities were maintained: a pick-up velocity of 7,000 feet per minute and a discharge velocity of 8,260 feet per minute, using 235 SCFM of conveying air.

While equipment for quantitatively measuring angel hair production by weight or volume was not available at the time, the amount of angel hair formed was thoroughly assessed by visually examining the pipe walls and the discharge from the angel hair remover. This visual assessment provided clear and strong evidence of performance differences.

Unveiling the Results: DELTA DUCON'S SPIRA/flo®'s Dramatic Reduction in Angel Hair and Fines

The test results clearly showed DELTA DUCON’S SPIRA/flo® Pipe's superior performance in reducing angel hair and fines, offering a distinct advantage for plastic pellet conveying. Let's look at the findings from the exact report:

1. Smooth Aluminum Pipe (Baseline Performance): The initial run used a smooth aluminum pipe as the control. The conveying rate was 4,800 pounds per hour. After the five-hour run, the pipe was taken apart, and the results highlighted how severe the angel hair problem is in traditional systems: about 90% of the straight sections and a notable 40% of the bends were heavily covered with a layer of angel hair. This set a clear baseline, showing the significant challenge posed by angel hair formation in typical smooth-wall piping within plastic processing environments.

2. DELTA DUCON’S SPIRA/flo® Pipe (Full System Superiority): After the smooth pipe test, a run was done using an all-DELTA DUCON’S SPIRA/flo® pipe setup, keeping the same blower RPM and piping arrangement as the smooth run. A feed rate of 4,000 pounds per hour was used.

The results were truly remarkable and confirmed a "dramatic reduction in formation of angel hair". After the run, visual inspection showed that only about 25% of the pipe interior was covered with angel hair. Importantly, the angel hair that did form appeared as distinct small, light, and loosely attached flakes (about 1/4" x 1/4"). The report specifically mentioned that these flakes were "very light and loosely attached to the pipe, so it appeared that it could be easily separated from the pellets in a cyclone". This is a vital difference for plastics producers, as it indicates that any minimal angel hair formed would be manageable and would not significantly harm the final product quality or operational efficiency. The report's confident conclusion was that "I feel this pipe would be satisfactory for plant operation".

(Note: While the original report included tests on other competitive treatments, such as dimpled/shot peened and cut groove pipes, paragraphs relating to these were specifically removed from the exact transcription as per the producer's request. However, the overall summary of the test clearly highlighted SPIRA/flo® as the best performer among all pipes tested.)

3. Mixed Pipe Configuration (Insight into Angel Hair Origins): An additional, insightful test was performed using a mixed pipe setup: smooth aluminum pipe for the straight sections combined with DELTA DUCON’S SPIRA/flo® for the bends. The pipe configuration and blower RPM stayed consistent with previous runs, and a 4,000 pounds per hour rate was achieved.

The results from this mixed setup provided valuable insight into where angel hair primarily forms: approximately 50% of the smooth straight sections were covered with angel hair, while only about 25% of the DELTA DUCON’S SPIRA/flo® bends were coated with the light 1/4" x 1/4" flakes. This outcome clearly showed that angel hair is produced in straight sections as well as bends. More importantly, it demonstrated that even when used with traditional straight piping, the presence of SPIRA/flo® in the bends significantly reduced angel hair formation. However, the overall level of angel hair production in this mixed setup was ultimately considered "unsatisfactory for plant use", reinforcing the need for DELTA DUCON’S SPIRA/flo® throughout the entire conveying line.

The Verdict: DELTA DUCON’S SPIRA/flo® - The Preferred Choice for Plastic Pellet Quality and Efficiency

In summary, the test report delivered a clear and compelling verdict for plastics manufacturers: "I feel that DELTA DUCON’S SPIRA/flo® pipe, used in both straights and bends, would be satisfactory for plant use". The report highlighted two key benefits directly relevant to the plastics industry:

1. Significant Reduction: The production of angel hair would be "significantly reduced" when SPIRA/flo® is used throughout the entire pneumatic conveying system. This directly means higher product yield and less waste.

2. Easy Separation: Crucially for plastics processors, the angel hair that might still form with SPIRA/flo® was of a specific type (light, loosely attached flakes) that "could readily be separated from the pellet stream". This minimizes post-processing challenges and helps ensure the purity of the final product.

   
   

The Science Behind SPIRA/flo®: A Delta Ducon Innovation for Plastics

What makes DELTA DUCON’S SPIRA/flo® Pipe so uniquely effective in reducing angel hair, a persistent issue in plastic pellet conveying? It's a testament to Delta Ducon's innovative engineering and deep understanding of material flow dynamics. The pipe features a unique, precisely engineered pressed groove interior. This distinctive design is critical for several reasons:

• Minimized Contact Area: Unlike smooth-wall pipes where pellets tumble randomly and maximize contact with the pipe surface, the spiraling grooves minimize the actual contact area between the pellets and the pipe wall. This reduces friction and the shearing forces that are primary causes of angel hair formation.

• Controlled Flow Path: The spiraling grooves gently guide the pellets along a more controlled path, significantly reducing direct impact against the pipe walls. This creates a smoother, less abrasive flow, which helps minimize the chaotic bouncing and rubbing that typically generate fines and angel hair.

• Reduced Static Buildup: The unique surface can also help reduce static electricity buildup, which can cause pellets to stick to the pipe wall and further worsen angel hair issues.

This innovative design was developed by Ducon Fluid Transport, now known as Delta Ducon, LLC. The name SPIRA/flo® itself suggests the spiraling, optimized flow it creates, a direct result of decades of research, development, and real-world application in pneumatic conveying.

Delta Ducon's Legacy of Performance in Plastic Pellet Handling

The test was not just a historical event; it marked the beginning of a long-standing, successful partnership. The impressive and documented performance shown by DELTA DUCON’S SPIRA/flo® Pipe in that key trial has made it the preferred choice for that major polyethylene producer for over 45 years. This lasting relationship is strong evidence of the real-world benefits and long-term reliability that SPIRA/flo® provides in the demanding environment of plastic pellet conveying.

At Delta Ducon, our expertise extends thoroughly across all aspects of bulk material handling, with a specific focus on the subtle needs of the plastics industry. Our century of experience in handling highly abrasive materials across diverse sectors like cement, mining, minerals, steel, power, and building products, provides us with a unique and strong foundation. We use this deep knowledge to bring a complete understanding to pneumatic conveying systems for plastics. We specialize in designing, manufacturing, and installing complete conveying solutions that prioritize:

• Product Integrity: Our main focus is on minimizing product degradation, angel hair, and fines, ensuring your plastic pellets keep their quality from the railcar to processing.

• Operational Efficiency: We engineer systems for consistent, high-volume flow, optimizing throughput while aiming for reduced energy use.

• System Longevity: Using extremely strong components, including our patented SPIRA/flo® pipe, we ensure your conveying system withstands continuous, demanding operation for decades.

• Reduced Maintenance: Our designs emphasize reliability and ease of maintenance, leading to less downtime and lower operational costs—a critical factor for any plastics manufacturer.

  
  

Whether you're conveying polyethylene, polypropylene, PVC, or other types of plastic pellets, powders, or granular materials, the fundamental principles of minimizing friction, impact, and shearing forces are universal and crucial for product quality. Delta Ducon's dedicated engineering team uses this deep knowledge to custom-design pneumatic conveying systems that meet your exact needs. This ensures your material handling operations are not just efficient but are optimized for product quality and long-term reliability.

The proven performance of DELTA DUCON’S SPIRA/flo® Pipe stands as a clear example of Delta Ducon's commitment to innovation and engineering excellence in bulk material handling. For operations where material quality, conveying efficiency, and system longevity are essential, trust the lasting performance of DELTA DUCON’S SPIRA/flo® and the expertise of Delta Ducon. Visit www.spiraflopipe.com or contact us directly to learn how our solutions can help with your plastic pellet conveying challenges.