Quality Control & Inspection Systems Update

By Karen Bitz McIntyre, Editor | February 15, 2012

A look at how quality control and inspection systems are helping move nonwovens and disposable products forward

On the production line, the slightest flaw can be a big deal, not only costing companies financially but also hurting their reputations among customers. To prevent catastrophe, makers and converters of nonwovens are investing more heavily in quality control and inspection systems to stop problems before they arise. And, these manufacturers, in turn, are coming up with a lot of exciting new developments to stop mistakes before they happen.

AccuSentry’s applied automated inspection solutions for nonwoven and absorbent hygiene manufacturers deliver powerful quality tools that enable realtime process control. Their Centerlining Package provides an effective means for manufacturers to transform automated inspection data into powerful process control data in the form of realtime graphs displayed on an operator dashboard. This allows manufacturers the ability to take control of their process consistency by standardizing production setup across shifts, operators and product styles.

Accusentry’s Centerlining dashboard gives line operators access to a number of critical parameters.

This Centerlining dashboard places critical product measures front and center to allow the operator to quickly monitor the status of the process at all times, and give them objective control over production variations during startup and changeover. Standardizing control of the production process in this way simplifies operator training, improves production consistency and offers significant cost savings.

Each graph on the Ceterlining dashboard correlates to a specific process on the machine. The operator runs the production line based on a set of established targets, presented as “centerlines” on the graphs. While the line is in operation, they adjust the natural process variations to fluctuate around those centerlines, keeping key product parameters within a tolerance range. The dashboard alerts the operator when a parameter is sliding out of specification. The operator then adjusts the machine based on the data presented.

Centerlining effectively removes the inefficient cycle of sample retrieval, measurement and feedback for machine adjustment. Tolerances can be set and then micro-adjusted by monitoring the process as a whole instead of constantly sampling individual products. Operators constantly hone equipment performance and proactively marshal support resources to achieve maximum production efficiency.

Mining valuable control data from the Centerlining Dashboard not only removes production variability, but also helps plant management translate and monitor organizational production goals directly to line operators. Successful implementation of this package requires proper training and a commitment from the plant management to the line operators. Centerlining delivers significant improvements across operations, thereby enabling the manufacturers to achieve unparalleled performance levels.

Beta LaserMike
Beta LaserMike, a leading global provider of precision measurement and control solutions, has introduced the LaserSpeed differential speed measurement system to help nonwovens manufacturers accurately control the web tension of product during manufacturing. Most manufacturers currently control web tension by either trusting the speed that their drives are reporting or using a mechanical contact encoder. While drives are becoming more sophisticated and more accurate every year, the simulated encoder output from the drive cannot compensate for slippage. Every product has some amount of slippage on the drive roller. The amount that the product slips can change based on texture, product composition, or even tension at other points on the production line. Contact encoders experience similar issues.

Beta LaserMike’s differential speed measurement system solves this problem by measuring the differential speed of the web at two different locations without making contact with the product. The system uses the LaserSpeed Length Differential Indicator (LDI) and two LaserSpeed non-contact laser encoders to monitor the two different line speeds. The LaserSpeed encoders are placed at two critical measurement points on the line, for example, at the exit side on the unwind station and the input side of the rewind station. Since the LaserSpeed encoder measures the product itself and not the drive roller, slippage is not a problem. Speed measurements are captured with better than ±0.05% accuracy and 0.02% repeatability, enabling the manufacturer to precisely monitor and control the required amount of tension on the web.
BetaLaser Mike’s LaserSpeed differential speed measurement system helps nonwovens makers accurately control web tension.

The Differential Speed Measurement System can be equipped with either the LaserSpeed 4000 encoder for unidirectional measurement or the LaserSpeed 9000 encoder to measure forward and reverse directions as well as down to true zero speed to control very slow movements. Both versions can be interfaced with a PLC to control the differential speed and can be connected to a light stack or alarm to notify an operator when the differential speed exceeds tolerances. The LaserSpeed encoder is designed for heavy industrial environments, is easy to install, and is factory calibrated for low-maintenance operation. The measurement is performed optically, so there are no parts to wear out.

Cognex Corporation
Cognex Corporation has launched a new fixed-mount industrial ID reader—the DataMan 300. According to the company, the DataMan 300 is designed to handle the most difficult ID code-reading applications on even the highest speed lines. These new readers dramatically increase barcode read rates and speed with a new 1DMax+ algorithm, which incorporates groundbreaking new “Hotbars” technology.For 2-D matrix and difficult-to-read DPM (Direct Part Mark) codes, reading performance has also been significantly improved from a major upgrade of 2DMax to the 2DMax+ algorithm. With the DataMan 300, set up and deployment is even easier than before, with modular, controllable lighting options and a unique intelligent tuning system.

“It just reads. Period. The DataMan 300 can read any code we challenge it with,” says Carl Gerst, vice president and business unit manager, ID Products. “Besides unprecedented read rates, the DataMan 300 reader is our easiest to install and maintain, saving our customers time and money—two things they need to allocate to other areas of their operation in order to be successful.”

DataMan 300 series offers two models. The DataMan 300 provides standard resolution of 800x600 pixels and the DataMan 302 is the high resolution model at 1280x1024 pixels. The DataMan 302 is ideal for reading very small DPM codes on small components to ensure full part traceability—a trend for the automotive industry, for example.

Strong-performing code-reading algorithms have been advanced, taking a quantum leap beyond the current best-in-class technology. 1DMax+ with patent-pending Hotbars technology is a breakthrough in image-based barcode reading. Invented by Cognex’s 31-year veteran Bill Silver, Hotbars uses texture to locate barcodes at any orientation, and then extracts high-resolution 1-D signals for decoding. With a solid mathematical foundation and meticulous assembly language programming, Hotbars combines superior signal fidelity with lightning speed, giving the next generation of Cognex DataMan readers unprecedented performance. The 2-DMax+ algorithm is also an upgrade from existing 2DMax technology offering tremendous enhancements in handling damaged codes at high line rates and poorly marked or extremely damaged codes. Both algorithms allow for the highest read rates possible.

In another leap, the DataMan 300 series offers the flexibility of integrated and controllable modular lighting and optics. The user can purchase just one model and choose the appropriate lens for their required working distance and field of view. The controllable, field changeable lighting modules allow the user to create the best possible lighting for their part, ensuring optimal read rates.

The Mahlo DML Laser Caliper Sensor utilizes a very high precision laser triangulation sensor both above and below the web to measure absolute thickness directly.This measurement is completely non-contact and non-nuclear. The lasers use the principle of optical triangulation, whereby the light reflected from the web is focused on a high resolution CCD sensor originally developed for the digital camera industry. As the distance to the web changes, the light is focused at a different location on the CCD.

A very useful feature of the Mahlo laser is that it not only measures the position on the CCD, but also measures the total received intensity.The intensity measurement is used to close-loop modulate the power supply to the laser emitter so that there is absolutely no sensitivity to changes in web color, gloss, translucency or surface reflectivity.

Mahlo’s DML Laser Caliper System

The Mahlo DML Laser Caliper Sensor is offered in two versions, one with a dynamic measurement repeatability of better than 0.001 inches (1 mil), and a high-precision model with active radio frequency compensation with a measurement repeatability of0.0002 inches (0.2 mils, 5 microns). Measurements of up to 4 inch thick webs are possible.

In addition to the fundamental sensor performance, innovative tools are standard in the Mahlo QMS-12 QCS System software that allow user-selection of a variety of Laser Caliper measurement modes such as peak-picking, valley-picking, averaging and false measurement rejection (for very porous or perforated webs).

The Mahlo DML Laser Caliper Sensor provides the most accurate, reliable direct measurement of thickness available and is proven in the many challenging field applications.

Ryeco’s marking systems can fit any kind of nonwovens line.

Inspecting for defects is no longer enough if you want to promise defect-free products to your customers.For years companies have been inspecting their products for defects but not removing the defects they find.Ryeco marking systems allow you to mark all defects for later removal.

Ryeco offers a variety of Marking systems to fit any nonwoven line.Marks can be placed on the edge so they appear as a ring on the end of a roll or can be placed on the surface near the defect using a lane marker.With the addition of a Mark Detection system the line can stop automatically when a defect approaches during the unwind process.

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