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Rotary hot-air bag sealers elevate operating efficiencies

Contract packer installs four units to accommodate high-speed, high-production demands of major paper products manufacturer.

Pw 6382 United Warehouse Ok Intl A

United Warehouse, Tulsa, OK, specializes in value-added warehousing, distribution, and contract packaging services, with emphasis on bottled beverages and bagged paper products. With locations in three states, the company operates well over 1 million sq ft of warehousing and distribution facilities.

Contract packaging manager Scott Surber says, “Often, it takes some effort to convince clients that doing everything themselves isn’t always the most cost-effective strategy. By handling the details of packaging, storage, and distribution of their products, we free up time for our customers to concentrate on their own core competencies.

“Our clients view United Warehouse as an extension of their own operations, and they trust us to ship their products directly to their customers. So quality assurance and traceability are of the utmost importance.”

Sealing equipment search

“Sealing paper products such as bath tissue and paper towels make up about half of our contract packaging operations at present,” Surber notes. “We currently package about 20,000 products per day for the largest manufacturer of paper towels and tissue in the world.

“We started this particular project in May 2006. We had used thermal impulse sealers on occasion for some other smaller projects. But this was our first packaging assignment that required sustained, high-speed bag sealing. So we didn’t quite know what type of equipment would be necessary. The customer-supplied, preformed film bags we needed to seal were fairly large, preprinted (including graphics, logos, and UPC bar codes), and about 2-mil thick. In order for us to reach our production targets, the bags would need to be filled and sealed with speed and accuracy. And the seal itself needed to be flawless and consistent. There were several types of sealers on the market, but none seemed to be able to deliver the speed and quality we were looking for.”

United Warehouse was hoping to source an Oklahoma-based manufacturer for the new sealing equipment. The company contacted several local manufacturers without much luck.

Recalls Surber, “It was a search of the Internet using the keywords ‘OK’ and ‘bag sealing’ that hit pay dirt for us. The company we found wasn’t located in Oklahoma. But the equipment we found on the OK International web site ( looked like just what we needed.

“Because this was an important decision, I made a quick trip to the Boston area to visit OK International’s headquarters. The sales staff was friendly and knowledgeable. The shop was clean and organized. And everyone seemed committed to making sure we got the right equipment for our specific application. Once we met the team at OKI and had an opportunity to see a trial run of the Supersealer SS1™ in action, we knew that it was the right product for our project. So we purchased four of them on the spot!”

Installation and start-up

When the four sealing units were installed at the Tulsa plant, United Warehouse staffers only had to contact OK International technicians a couple of times for assistance. Surber notes, “Installation was pretty straightforward, and the OK technicians were very helpful and knowledgeable.”

The SS1 Supersealers came complete with trim attachments and adjustable height pedestals. In addition, to work in synchronicity with the new high-speed sealers, United Warehouse purchased a gravity-fed conveyor system manufactured by Roach Conveyors ( and two high-speed pallet wrappers manufactured by Lantech, Inc. (

Surber says, “This is a very user-friendly and safe system to run. Operators can be trained on the proper sealer settings and safety features in just a few minutes. And they can be achieving quality seals right from the start. Our bags require a bottom gusset seal, which takes a little practice. But the sealer speed can be adjusted easily to allow the operator to become proficient at his or her own pace.”

To achieve bag sealing, the operator inserts each manually filled bag into the inlet of the Supersealer, and the machine does the rest. The bag is automatically pulled into the machine by enclosed drive belts; the excess film is trimmed from the top; the bag is hot air-sealed at constant temperature; and the sealed bag then is automatically routed through the machine exit.

United Warehouse workers manually erect and load the corrugated shipping cases (supplied by the contract packing customer), then seal them using automatic taping equipment from 3M Industrial Products (, acquired through local distributor Xpedx ( The shipping cases are coded using equipment from Kiwi (, Loveshaw MicroJet (, and Squid Ink Manufacturing, Inc. (

Super performance

Currently, United Warehouse is filling and sealing more than 50 different bag sizes—from a small six-pack of paper towel rolls to a huge 120-pack of toilet tissue rolls. Surber notes, “The sealing speed really depends on the length of the seal. For example, for an eight-pack of paper towels with a seal approximately two feet long, we average sealing speeds of 20 bags per minute. Changeovers from one bag size and seal length to another are quick and easy with the PLC pushbutton controls. We simply adjust the sealing speed, temperature, and height of the pedestal. The procedure takes about ten minutes.”

Cleaning and maintenance of the sealers also is easy. Surber explains, “We use compressed air to clean the inside of the sealers after each shift. And we inspect operating parts, sensors, and belts every few days. If parts are needed, we send an e-mail to our designated contact at OK International and normally receive the items a few days later.”

Summing up United Warehouse’s experience with the Supersealers, Surber says, “Two full years into this project, I think the best attribute of the OK International bag sealers is their reliability. We have sealed more than 13 million bags with our four Supersealers, and our customers have been impressed with our rate of production, our quality, and our flexibility. These sealers are helping us stay competitive in today’s contract packaging market.”

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