International Specialty Products (ISP), an $800 million specialty chemicals company, has developed a highly effective formula for success: equal parts manufacturing expertise, quality control, and customer-centered service. And while the chemicals produced at the company''s Freetown, MA-based facility often comprise a small percentage of the products in which they are used, they are nonetheless vital in those products, which serve the pharmaceutical, photographic, personal care, agricultural, coatings, and polymer industries.
Until recently, though, some of the specialty chemicals produced at the facility were not flowing smoothly -- specifically, a raw material used in producing a hair spray ingredient was creating some manufacturing challenges. ISP received the material in bulk bags and wanted to load it directly into its process vessel. But unlike a material with high granularity, this fine powder tended to form "rat holes" in the bulk bag in which it was delivered, preventing the material from being fed easily into the process vessel.
And ISP had other reasons to reevaluate the method used to charge this raw material, according to Fran Minnock, a 12-year veteran in the company''s Process Engineering and Quality Assurance department.
"We needed to control the dust that the material generated into the production atmosphere. We needed to improve efficiency and we needed to accomplish this in an oxygen-free atmosphere," said Minnock.
ISP evaluated several solutions, such as screw conveyors and other vacuum conveyor technology suppliers, but ultimately turned to PIAB Inc, a leader in industrial vacuum conveying technology located in Hingham, MA.
PIAB delivered a conveying system consisting of an air-driven vacuum conveyor, pneumatic controller, and bulk bag unloader. "PIAB provided us with the two most important elements in our decision-making process, these being a complete solution as well as a cost-effective price," asserts Minnock.
"The quality and flexibility of PIAB''s products were far superior to the other solutions we evaluated. The fact that we could remotely mount the bulk bag unloader away from the actual conveyor appealed to us," says Minnock.
Another benefit to ISP was the ability to test the flow of its product under real-life conditions, using both PIAB''s fully equipped testing facility in Hingham, and a unit at the production site. PIAB offers all of its potential customers the use of the test facility, running a wide variety of materials to assess their conveying characteristics -- and identify any possible challenges -- over distances of varying configuration.
"There''s no doubt that the use of PIAB''s testing facility and the use of the unit at the site was a strong selling point for us," said Minnock. "It''s not enough for us to see some theoretical equations on a blackboard. We needed to see how our process would work in the plant. PIAB gave us the chance to do that."
"PIAB''s C-Series 33 Vacuum Conveyor offered us many features to help improve the process," adds Minnock.
The C-Series conveyor''s modular design makes it easy for ISP to adapt the conveyor to suit its specific needs, and its stainless steel construction provides the hygienic (USDA and 3-A accepted) and corrosion-resistant characteristics desired for this application. The conveyor can transport the raw material safely and quietly, and is corrosion-resistant and easy to clean.
Another benefit is that the vacuum conveyor is 100% pneumatically operated, eliminating any need for an explosion-proof electrical rating. And because the conveyor incorporates few moving parts, routine maintenance and downtime are greatly minimized.
The PIAB vacuum pump, at the heart of the vacuum conveying system, is driven by compressed air and is characterized by high flow rates and deep vacuum down to 27 inHg. Since the pump puts the energy in its compressed air supply to maximum use and efficiency, overall energy consumption is low. The pump is also quiet, producing only 72-76 dB(A).
Used in conjunction with the compressed air-driven vacuum conveyors, the PIAB bulk bag unloader is a simple, fully contained stainless steel unit. The bulk bag is elevated above the station and its spout attached -- before being untied -- to an inflatable seal, providing for a totally dust-tight connection. This eliminates the need for gloveboxes, doors, or enclosures, and there is no dust connection. The PIAB bulk bag unloader is also easily disassembled for periodic cleaning.
In the manufacturing process that produces the hairspray ingredient, the bulk bag unloader is positioned under the hanging bulk bag, with the spout of the bag attached to the unloader. A pneumatic seal creates a dust-tight connection between the bag and the vacuum conveying system''s feed assembly, which has a nitrogen-fluidized cone to assist product flow toward the feed point. The nitrogen serves two purposes: it fluidizes the powder and inerts the transport piping. The entire feed assembly is mounted on a large pneumatic cylinder.
If rat holes form in the bulk bag, the cylinder extends, lifting the feed assembly up into the bag, breaking up the bridges in the material and allowing fresh material to flow toward the feed point. The cylinder can be raised and lowered manually, or configured to cycle up and down automatically.
The time savings, as well as the reduction in labor, have been dramatic. In addition, the entire manufacturing process is far more efficient. Previously, it took three people charging 23 bags, moving them manually into a vessel, lifting them up onto a hoist, and holding them over a manway. Ultimately, it took these three people a total of 10 hours to prepare the batch for the reactor. With the new PIAB equipment, that process was decreased more than 50%, to four hours.
ISP can now charge bulk bags quickly without oxygen in an inert atmosphere, do it safely, maintain a high level of cleanliness in the plant, and do it despite the fact that the raw-material powder did not have good flow properties.
That''s a formula for success that should keep ISP''s manufacturing process -- and profits -- flowing freely for a long time to come.