Some of our projects solve equipment problems. This one was more complicated: transferring institutional knowledge across an ocean, then building the infrastructure to support that expertise in a new regulatory environment, all in the service of resin handling.
A global specialty chemical and materials manufacturer produces polyvinyl butyral (PVB) interlayer film used in laminated safety glass. The film is sandwiched between two layers of glass in automotive windshields and architectural applications, including high-rise curtain wall systems, where it holds shattered glass in place on impact.
The company operates production facilities on multiple continents and has built its interlayer products into some of the most demanding glass safety specifications in the world.
When the company decided to establish PVB film extrusion in the United States, the project required more than building a new line. The company needed to replicate a material handling approach that operated successfully in Germany for years, including a resin unloading method common in Europe but rare in U.S. facilities.
The primary raw material for PVB film production is Butacite® resin, a polyvinyl butyral polymer delivered in 20-metric-ton shipping containers. At the company’s European facility, containers are offloaded using a tilt unloader: the trailer is backed onto a hydraulic platform, uncoupled from the tractor, and tilted up to 45 degrees so the resin discharges by gravity through ports on the container. From there, it’s conveyed pneumatically into storage silos.
The tilt unloading method the company relied on wasn’t common practice in the States, and no off-the-shelf solution existed for the new facility in North Carolina.
The goal was clear: replicate the European process, maintain the same throughput rate, and design the system to meet U.S. safety regulations, including NFPA and OSHA requirements for combustible dust handling. AZO was brought in to engineer the full upstream resin handling system around a tilt unloader the customer sourced to match their European operation.
Butacite® PVB resin comes in flake form. It’s a physically stable material under normal conditions, but it presents real handling constraints. Above 70°C, the resin can begin to form lumps, complicating transport and the feeding process. And when it sits in storage, older material can oxidize and shift in color as opposed to freshly received resin. For a product that ends up in automotive windshields and visible architectural glass, color uniformity matters.
The dust explosivity characteristics of PVB resin also required careful consideration. PVB flakes are classified in the lowest risk group for dust explosion, but fine particles collected during processing have electrostatic properties that need to be managed. Any handling system had to meet applicable NFPA standards for combustible dust as well as satisfy the company’s own internal safety review process.
Beyond the resin, the full system also needed to handle the other ingredients fed into the extrusion process: plasticizers, adhesion additives, and liquid. Each had its own feed rate requirements and integration points with the main extruder.
AZO designed the complete upstream material handling system for the new U.S. extrusion line, working from the tilt unloader through to the extruder feed.
Resin discharged from the tilted container flows through a vibrating screener conveyor and is transferred pneumatically into a 60-ton storage silo. From the storage silo, material moves to a 60-ton blend silo with two rotary valves. The blend silo actively circulates resin at 3.3 tons per hour so incoming material homogenizes with existing stock, keeping color consistent throughout the batch. The blended resin is conveyed to a day tank sized for production batches, which then delivers material to the main extruder belt feeder.
On the liquid side, AZO provided mixing and feed tank systems for the plasticizer and adhesion additive streams, each with dedicated gear pumps and injection lines delivering precise flow rates to the extruder.
All dust-generating equipment was designed to meet NFPA standards for combustible dust, with bag filtration systems on the storage and blending silos sized and specified accordingly. Equipment was also designed for easy cleaning and safe dismantling, in line with the company’s own safety standards.
The project was delivered on schedule despite a complication that no one had anticipated: the COVID-19 pandemic.
The German-based commissioning engineer couldn’t travel to the US. No one had previously remotely commissioned a system of this complexity, but the teams adapted. The AZO technician was on-site at the customer’s facility, guiding the process through video and real-time wearable camera technology, while the commissioner stayed in Germany. The process went off without a hitch.
The outdoor storage silos presented a separate logistical challenge. Silos of this size aren’t typically shipped across oceans, but the client sought confidence the equipment would perform correctly in the new facility. To support that requirement, AZO purchased and coordinated the shipment of the silos from Europe to ensure the specifications matched what worked at the Germany facility before installing them at the new facility. Start-up went without incident.
The customer wanted the system running by Q4 2020, and AZO was the first vendor to complete commissioning in September 2020 ahead of the requirement. The tilt unloading process the customer had used in Germany was successfully replicated in the U.S., with all NFPA and OSHA requirements met.
The customer’s project team recognized AZO’s field support specifically. AZO’s technician arrived early every morning, participated in daily production meetings, and stayed involved through every stage of the material transfer process: from the first load into the storage silo through ongoing adjustments to blower pressures and feeder settings. The tech also helped troubleshoot smaller installation details, including gaskets, hoses, and level probe placement.
The customer’s project manager described the support as bringing "A wealth of knowledge of how the material handling system should operate," and noted that AZO was the first vendor on-site at start-up.
Even though an entire unloading process didn’t exist in the U.S., AZO stepped in to help this manufacturer recreate it. AZO’s ability to adapt, including commissioning a first-of-its-kind system remotely during a pandemic, reflects the kind of partnership manufacturers need when they’re doing something that hasn’t been done before in their market.
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