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Nonwoven Laminations: Absorb Profit

Tranquility adult disposable incontinence products are the flagship brand of Principle Business Enterprises, Dunbridge, OH. A roll of the nonwoven material produced at its separate division, Gelok Intl., has intrinsic value. So when management discovered not only mechanical issues but also that it was literally giving away 2% or more of each nonwoven roll following slitting and cutting of the superabsorbent laminate and composite material, they knew something had to be done.

These products are used to remove water, aqueous solutions, odors, hydrocarbons, blood, urine, or other substances. Applications include personal hygiene, packaging, spill control, filtration, medical cleanup, wound dressing, manufacturing, and other operations where absorbency is needed.

In the lamination area at the Gelok operation, the company was experiencing inconsistent length measurements at its slitter/rewinder station. This station operates on a single-shift schedule, five days a week.

The slitter/rewinder typically runs 48-in.-wide rolls of laminate with material lengths up to 5,000 lineal ft. This station cuts a variety of products ranging from 1¼ in. to 48 in. on slightly larger rolls.

Line speeds vary on different roll sizes. For example, 12-in.-wide rolls are processed at 100-500 fpm, depending on the application.

Gelok produces and cuts laminates from various materials and in diverse combinations. These range from thin-layer cellulose to air-laid and nonwoven materials.

The slitter/rewinder station used a mechanical wheel encoder to measure product length, and over time the device began to wear and provide erroneous readings. The mechanical encoder also would slip because of the lubricants used on the slitter to separate the rolls of product. As such, the mechanical encoder required constant maintenance and recalibration.

The other downside was that the plant was shipping too much product to its customers. In bad months, inaccuracies at the slitter/rewinder station were as much as 2.5%.

For example, the company was under the impression it was delivering 1,000 lineal ft of material when in actuality it was delivering 1,025 lineal ft. With this excess amount, each roll was costing Principle Business Enterprises a significant amount of money in unnecessary expense.

The company needed an accurate, noncontact length measurement system to ensure it delivered the exact product quantity as specified by its customers.

Noncontact Encoder Ensures Accuracy

Principle Business Enterprises installed a Beta LaserMike LaserSpeed 4000 noncontact encoder on the slitter/rewinder, downstream of the lamination line. It has proven its worth over time.

The LS4000 uses advanced, laser-based technology to measure precisely the length of product as it's slit and rewound. The system is said to capture length and speed measurements with better than +0.05% accuracy.

The LS4000 projects a unique pattern on the surface of the laminate product. As the product moves, light is scattered back to the unit. This information is translated into product speed, and pulses are produced to determine the product length.

Critical Process Factors & Installation

The determination to implement an LS4000 at the Gelok facility was driven by several demanding process requirements. The unit had to provide accurate length measurements for various substrates and material thicknesses running at the different line speeds. Also, plant personnel did not want to go through the time-consuming task of recalibrating the encoder for every material thickness.

In addition, the LS4000 needed to provide the capability for quick cleaning, since the slitter operation produces a significant amount of dust and debris from cutting operations and superabsorbent powder residue. The LS4000 met all the requirements.

The LS4000 is mounted to the slitter frame on the infeed side of the parent roll. The unit is positioned perpendicular to the incoming material at the slitter.

The measurement area is stabilized through the use of two idler rollers to minimize product movement. Slitter blades are located downstream after a series of idler rollers. The standoff distance of the LS4000 encoder to the web material is set at 12 in. At this position, the LS4000 produces a 1.4-in. depth of field or “measurement zone” to detect product movement accurately. The length measurement is output via a PLC to a counter device and is displayed in lineal feet.

Principle Business Enterprises produces $2 million to $4 million of Gelok product per year on the lamination line. Since the implementation of the LS4000, the company realized a return on investment very quickly while benefiting from other advantages of noncontact laser measurement.

Richard LaVoie, general manager for Gelok, summarizes the benefit in saying, “Beta LaserMike's LaserSpeed product has operated reliably at our plant for years. It has saved us a significant amount of money, and we're no longer giving away two percent of material because of the inaccuracy of mechanical wheel encoders. We're also very pleased with Beta LaserMike's level of quality and responsive service.” So pleased, in fact, Principle Business Enterprises has implemented a second encoder in its production operations to check the length accuracy of incoming vendor material rolls.

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Direct Benefits Realized

Principle Business Enterprises, Dunbridge, OH, reports the following benefits after installing a Beta LaserMike LaserSpeed 4000 noncontact encoder on a slitter/rewinder station:

  • Eliminated product give-away by 2%, representing $40,000/yr in savings (2% of $2 million)
  • Realized a return on investment on the LS4000 encoder in 3 months
  • Minimized waste, product give-away, and bill-backs from customers due to higher accuracy measurements
  • Eliminated routine recalibration and mechanical maintenance due to permanent calibration and no moving parts
  • Enabled rapid clean-out of optical path to maximize production uptime with quick-change window feature
  • Freed critical personnel to perform other valuable jobs in the plant rather than monitor and service the measurement system

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