Run silent, run cheap
Groton, CT--The primary purpose of a nuclear attack submarine (SSN) is to attack enemy submarines. However, politics have left the bulk of the Soviet-cum-Russian submarine force rusting at its moorings, and American submarine makers rather high and dry.
Like a dive alarm, the advent of real peace has awakened officials at Electric Boat to the necessity of redefining the business of designing and building their principle--and, in reality, only--product. The defense contractor has followed the examples of Boeing and Chrysler in adopting the CATIA CAD/CAM package from Dassault Systemes, Paris, France, for nearly all aspects of the product development cycle.
The latest program to get the green light at Groton is the so-called New Attack Submarine (NSSN), which the Navy wants to replace its maturing fleet of Los Angeles-class SSNs starting around 2004. Design of the new boats is well advanced, and engineers say CATIA has been instrumental every step of the way. In fact, NSSN is the largest, most complicated CATIA project anywhere in the world. This represents a sea change at Electric Boat. All other submarines were designed on paper, from the Holland built in 1900 up to and including, astonishingly, the Seawolf-class.
One of our submarines is missing. Conceived in the Red October era, the Seawolf is the most capable attack sub ever built. It is also the most expensive. Each boat costs between $2.5 and $3 billion.
The Seawolf displaces 9,150 tons submerged compared to the Los Angeles's 6,900, enabling greater weapons load and patrol endurance. The former is supposed to be quieter at high speed than the latter is sitting at the pier. In the sub-hunt game, quietness equals victory.
The first unit, USS Seawolf, is undergoing sea trials. The second, USS Connecticut, should be completed in 1998. Funding for a third unit has been approved for delivery in 2001. And that's all she wrote.
"We're on life-support," admits Craig Haines, Electric Boat's vice president of quality and information technology. "The Seawolf will just keep us in business until the NSSN goes into production."
"The Navy can't afford to buy 20 Seawolves," explains William Lennon, deputy program manager for the New Attack Submarine. "So our goal is to provide certain Seawolf-type capabilities but cheaper."
Cheaper means each NSSN will cost about half as much as a Seawolf. The new class is significantly smaller, displacing 7,700 tons, and will not be quite as fast, nor as deep diving, nor as quiet as its better-appointed predecessor. However, the NSSN will offer a number of advantages in performance and firepower over the Los Angeles boats, such as a vertical launch system for tactical missiles similar to those found on Arleigh Burke-class destroyers and later Ticonderoga-class cruisers.
Electric Boat is also designing NSSN with post-Cold War combat in mind. The Navy has specified requirements for the new sub to carry and deploy troops, unmanned submersibles, and advanced mines.
Perhaps the most innovative design feature of NSSN is its modular construction arrangement. A series of bays, each supporting related equipment and functions, slide into sections of the sub's pressure hull like boards in a PC. The NSSN is designed to be disassembled, so particular modules can be removed for ease of maintenance or even replacement by more advanced modules. This way, the Navy hopes to keep the NSSN up to date and effective for decades.
Diving deep. In order to survive in the submarine business, Electric Boat found it necessary to embrace those design and manufacturing technologies that have helped revitalize other troubled industries in the not-too-distant past. The transition has not been tentative: Over 950 seats of CATIA Version 4 have been installed on a mainframe and a network of 300 IBM RS/6000 workstations. What's more, every component and section of the NSSN will be designed electronically and evaluated in digital or physical mock-up before steel is ordered.
"The most important ability we have obtained from migrating to CAD is flexibility," Lennon says. As an example, he cites an early design specification for NSSN that dispensed with dihedrals, which are small fin-like planes attached near the rudders. Eliminating them would reduce drag. However, subsequent analysis showed the boat's stability would suffer in their absence, and the dihedrals were put back in the design. "Similar revisions to the design at such a late date under a paper-based system would have caused several months' delay," Lennon says. "With CAD, the design team handled the changes in less than a month."
According to Haines, a major time- and cost-saving device of the NSSN program has been to link the design and manufacturing processes. "Historically, design was a single activity by contract," Haines says. "Now, the Navy has awarded a joint design and build contract for the NSSN. For the first time, this allows us to approach a project in a totally integrated way."
Linkage has been achieved through a common database of CATIA geometry accessible by both design and manufacturing engineers. Product data management (PDM) is regarded as key to this achievement, and the CATIA Data Management system was cited as one of the chief reasons Electric Boat went with Dassault/IBM. PDM works in concert with the Artemis product definition system from Computer Sciences Corp. (CSC) for document control and product scheduling. In addition, Electric Boat has outsourced all "non-strategic" application development, processing, and MIS functions to CSC.
Haines insists PDM and software-based program definition have drastically improved the efficiency of the NSSN program compared with previous efforts. "In one instance, on the Seawolf we found the same part had 16 different numbers," he says. "People on different teams just couldn't find an existing number for the part, so they gave it a new one. Now that all the engineering teams are linked together, this doesn't happen."
Many of the parts going into NSSN never would have made the cut on earlier submarines. This is not through lack of quality, Lennon is quick to point out, but because they were not to military specifications. "We have found that 90% of the fasteners on a submarine can be commercial grade," Lennon says. "That's resulting in a savings on NSSN of $500,000 per unit. We are finding similar savings with off-the-shelf enclosures and other systems as well."
Electric Boat's engineers provide potential vendors with a component's performance requirements, volume, and touch-points. The component designers return drawings or CAD geometry--preferably the latter--which are fitted into the CATIA assembly. "It's an iterative process," Lennon explains. "CAD allows it to happen much more smoothly."
One of the most important design tools enabled by CATIA is Electric Boat's home-grown electronic visualization system, which can display life-size assemblies on a large screen. Designers, manufacturers, and representatives of the Navy can navigate through virtual mock-ups of NSSN compartments.
"We used to have to build physical mock-ups three to five times before the customer was happy," Lennon relates, indicating each iteration might cost $1 million. "Then we would generate 2-D drawings from the approved version and deliver them to the shipyard, who had concerns too."
Changes can readily be made to the CATIA geometry that support the electronic visualizations. Furthermore, when an arrangement has been agreed upon by all parties, including the shipyard, the 3-D CAD models are ready to drive the manufacturing process.
The only section of the NSSN being modeled in wood and plastic is the propulsion module, which supports the S9G pressurized water nuclear reactor. Notes Haines, with the barest hint of impatience: "The nuclear navy customer is not persuaded the aft section of a submarine can be built without a full-scale mock-up."
Laser sensor controls agricultural spraying
Orlando, FL--Schwartz Electro-Optics has adapted its laser range-finder and imaging technology to control agricultural spraying. The precision possible with the Treesense system cuts overspraying. Result: minimal environmental impact and cost savings on sprayants.
Treesense is based on Schwartz's Autosense II vehicle detection and classification system that scans an eye-safe infrared indium gallium arsenide pulsed diode laser beam. A silicon avalanche photodiode detector senses the reflected beam.
In agricultural applications, the sensor detects the presence and extent of foliage on each side of the sprayer. Spraying is limited to those volumes containing foliage--the sensor lets the sprayer accommodate both small and large adjacent trees as well as differing patterns and extent of growth.
BEI, South Haven, MI, was the first to outfit a sprayer, its Curtec-2000, with Treesense. Luis Martinez, a grower representative and vice president of Curtec of Florida, a BEI sprayer distributor, says the ability to accurately gauge a small tree means "you don't drown the tree. Material-wise we can save 15 to 60%, depending on how many resets are in the grove." Resets are new trees planted to replace dead ones, which in the average grove is 5% per year. He adds, "That's a significant amount with a tank containing $1,000 worth of material."
Previous sensing systems based on ultrasonics require more detectors and components, according to Martinez, and can pick up false readings due to birds, for example. Detection with the laser-based method can be thresholded to avoid such spurious positives. While orchard applications require a range of about 30 feet, which both sensor types can handle, Martinez says the laser system can be adapted to row-crop spraying using boom sprayers up to 50 feet long.
Treesense-equipped sprayers can speed along at 3 to 5 mph and still get a precise growth profile. The system microprocessor allows for custom software development for individual growers. This can include census information such as the number of resets in a grove block, the extent of vegetation, or the time to accomplish spraying of various chemicals. Growers could also program the system to estimate yield of fruit by reading orchard color.
Thermal-spray technology tops U.S. Plunkett Awards
Turnberry Isle, FL--The company that developed a one-step method for the thermal spraying of fluoropolymer ceramic and metal composite coatings walked off with the first-place prize for U.S. entries in the 1997 DuPont Plunkett Awards for Innovation with Teflon® at an industry award ceremony. Similar awards were presented to European and Asia Pacific winners.
Spray-Tech Inc., Newton, CT, in conjunction with Frank N. Logo Associates, East Northport, NY, perfected the ceramic and metal composite coating technology. It provides low friction, low wear, corrosion protection, and other benefits of Teflon fluoropolymer resin for machine parts and tooling. Key to the patented system is a thermal barrier that protects particles of Teflon PTFE resin against destruction by the extreme heat of thermal spraying.
Compared with a conventional two-step process, the technology saves energy, eliminates added quality-assurance steps, and improves performance reliability. The process also emits no VOCs and eliminates waste. The resulting composite coatings with the embedded particles of Teflon have demonstrated 50% less friction and 20% longer wear life than coatings without the material.
Second prize went to MCR Oil Tools Corp., Burleson,TX, for a radial cutting torch. The torch pyrotechnically cuts tubing in a fraction of a second--on site--in oil and gas wells. It uses a mixture of Teflon PTFE resin and powdered metal as a gas generator. The faster cutting technique reduces labor, rig operating time, and energy costs.
Lowered down the well, the radial cutting torch is positioned and then "fired" to produce a high-velocity jet of molten metal and gas that cuts through well pipes in a fraction of a second. The Department of Energy has calculated that, over time, the Radial Cutting Torch can save energy producers some $40 billion in costs.
White Knight Pumps & Fittings Inc., Hemlock, MI, won third prize for its Pneumatic LogicTM shifting mechanism. The device, made entirely of Teflon, is used in the company's reciprocating pumps. Because they are 100% fluoropolymer resins, the pumps constitute a major advance in maintaining the high purity of fluids in semiconductor and chemical processing operations.
The pump has two pistons in opposing chambers. The pistons are connected so that while one expels fluid from its chamber, the other draws on fluid. Driving each piston is a bellows that expands under air pressure and contracts when pressure is released. Air flow to the bellows is controlled by the shifting mechanism, which incorporates a shuttle valve.
International winners. Award winners also were recognized in the European and Asia Pacific regions. On the European scene, first prize went to Trifluor GmbH, Ochtrup, Germany--shared with 2H Kunststoff Gmbh, Wettingen, Germany, and Metallform Gmbh, Imst, Austria--for the Plexoform® wet, flexible flue liner system for low-temperature or calorific-value heating boiler systems. Lenzing AG, Lenzing, Austria, received the second prize for its PROFILEN® staple fiber for needle felts used as scrims and sewing thread in high-temperature filtration; Kureha Chemical Gmbh, Dusseldorf, Germany, took the third prize for its PTFE fluoropolymer reinforced with Kreca® carbon fibers to produce gaskets, seals, and wear rings with improved properties.
Award winners for the Asia Pacific region included: first prize, Nippon Valqua Industries Ltd., Tokyo, Japan, for a method to line large tanks with fluoropolymer sheets at the customer's site; second prize, Heliro Pty Ltd., South Wales, Australia, for a process to injection mold small, complex insulators for coaxial cable connectors; and third prize, Chukoh Chemical Industries LTD., Tokyo, for its heat-resistant laminating belt used in corrugated board manufacturing.
The awards are named after Dr. Roy J. Plunkett, the DuPont scientist who discovered the original PTFE fluoropolymer that DuPont markets under the Teflon trademark. First-place winners received $5,000, second-place winners $3,000, and third-place winners $1,500. Judges included: Drew Azzara, vice president, American Society of Testing and Materials; Yasuhiro Koike, associate professor, Department of Science and Technology, Keio University, Yokohama, Japan; Piet J. Lemstra, professor, Laboratory of Polymer Technology, Eindhoven University of Technology, Eindhoven, The Netherlands; Ann Van Orden, assistant professor, Department of Mechanical Engineering, Old Dominion University, Norfolk, VA; Alvin Scolnick, vice president, National Electrical Manufacturers Association, Rosslyn, Virginia; and Gary Chamberlain, senior editor, Design News.
Engineering take-out hits the spot
Chelmsford, MA--APC, a Billerica, MA-based manufacturer of uninterruptable power supplies (UPSs), possesses an extensive staff of mechanical and electrical engineers. Nevertheless, it sought specialized engineering support elsewhere for a ground-breaking new product--code named "Dark Star"--that required a radical enclosure design. The company brought in two ID firms for initial consultations on the pitfalls and the potentials of the design concept, and selected the Bleck Design Group to see Dark Star realized.
According to Tom Eagan, director of engineering at Bleck, his company's role was to supplement APC's internal resources by tackling particularly challenging aspects of the project--in particular those that called for the engineering of structural and functional plastic components.
The goal of Dark Star was to develop an easy-to-manufacture UPS system with minimized component inventory and maximized configuration possibilities.
Bleck's solution was to develop a building-block approach, with an elaborate main enclosure--termed, the garage--as the cornerstone. This 20-lb gas-counter-pressure-formed unpainted structural foam part would accept multiple variations of transformer, battery, converter, and electronics configurations. Such an arrangement would permit APC to package configurations and upgrades such as field kits that the customer would unwrap and slip into place in the garage. What's more, the components were to be blind-mated and hot-swapable.
"While aesthetic quality, structural integrity, and blind-mate design were challenging, the biggest challenge mechanically was balancing the constraints for the various mounting and design features," Eagan says. He indicates designing such a robust enclosure would not have been possible without the use of high-end CAD systems. Bleck engineers did much of the design work for Dark Star using the surface-modeling tools of Euclid 3 from Matra Datavision, Andover, MA.
APC has just started selling the finished UPS product, now dubbed Symmetria. The entire product-development cycle was just over two years. "Symmetria was made possible by a coordinated effort," Eagan says. "No one organization could have achieved it on its own."
Enclosure weathers plant-floor conditions
Foxboro, MA--When The Foxboro Co. set out to design its newest process control system, the company knew it needed a tough enclosure. Destined for plant-floor applications in the food and pharmaceutical industries, the system had to withstand daily hose downs and exposure to harsh chemicals. The company's choice: the PC industrial enclosure from Rittal Corp., Springfield, OH.
Measuring 6×3×3 ft, the sealed NEMA 4X enclosure houses a process control computer with intelligent automation software. The system features a CRT that provides a status update, as well as both keyboard and mouse that are watertight.
The enclosure itself is stainless steel to resist corrosion. It's available with a choice of three cooling options: an industrial air conditioner, a water-cooled unit, or an air-cooling system; and is delivered with the cooling method of choice built in. The enclosure's upper door is available in glass for maximum visibility, or in shatterproof fiberglass to prevent breakage in the event of an accident.
In addition to the variety of design options, Foxboro chose Rittal's PC enclosure because of its reasonable cost. Add to that past dealings with Rittal that were successful. "We also liked the fact that Rittal does all its own design and development," says Chris Dhupar, hardware development manager at Foxboro. "And, because it's a multinational company, we don't have to ship products from the U.S. to Europe. Rittal produces the same enclosures in Europe as it does here, so we can have products shipped directly to our European customers."
3-D visualization clears up molecular confusion
Morris Plains, NJ--Re-searchers at Parke-Davis use molecular modeling to create, modify, study, and test interactions between molecules in their efforts to design new drugs. In the past, they relied on tinker-toy models and crude wireframe computer drawings to visualize the complex interaction of drug and biological molecules. However, these tools did not adequately display the nooks, crannies, bumps, canyons, and holes of the molecules' topography.
Now, Parke-Davis uses high-speed workstations, advanced modeling software, and the 3-D visualization capabilities of CrystalEyes eyewear from Stereographics, San Mateo, CA, to create near-exact visual replicas of complex molecules.
"With CrystalEyes we've gained an understanding of the forces and factors involved in making a compound a potent drug. Before using this equipment, we didn't fully appreciate the role that those properties played," says Parke-Davis Research Associate Dan Ortwine.
CrystalEyes works with the user's computer display and software to transmit separate left-eye/right-eye images, creating the illusion that on-screen objects have depth and presence. The result: Crisp stereo 3-D images delivered without ghosting or double-image artifacts.
Alternately displaying left- and right-eye perspectives on a monitor using a standard bandwidth solves a major problem of the past--true control of the z axis. For remote manipulation and viewing of objects, stereo 3-D gives the user control of changes made to a structure on the screen along all axes, including the z axis. This control is essential for exacting real-time processes such as the docking procedure critical to modeling molecular interactions.
Today, instead of making 200 molecules using the old methods, researchers need create only 50 because they can reject the remainder with greater speed and certainty. "We know in advance that a situation won't work because a drug molecule doesn't fit into a cavity," says Ortwine.
Phenolic compound reduces brake-cylinder piston weight
Winona, MN--Performance advantages such as heat resistance and dimensional stability make thermosets ideal for replacing metals in many automotive applications. The latest: brake-cylinder pistons for articulated dump trucks, front-end loaders, container handlers, and lift trucks.
Component engineers at Rockwell Automotive replaced the previous piston's steel core with Fiberite's FM 4029F-1 glass- and mineral-reinforced phenolic molding compound. The material's heat resistance helps protect the piston's rubber seals from heat conducted through the brake-lining backing plate. This minimizes seal hardening and extends the seals' life, according to Pat Cadaret, Rockwell's senior project engineer for off-highway axles and brakes.
Another advantage: The piston weighs 66% less than its all-steel counterpart. "This means less drag after braking and longer lining life. Our O-ring retraction system requires less force and quickly backs off the pad after braking," says Rockwell Brake Engineering Manager Bill Hayes.
Thermal specifications include a glass transition temperature above 572F and a coefficient of thermal expansion of 13 ppm/C. Hayes reports that test comparisons of two other molding compounds indicate FM 4029F-1 material is most easily processed using Rockwell's compression-molding technology.
The number of new thermoset applications nearing production or in development at OEMs or tier one suppliers in both the U.S. and Europe is at an all time high. As thermosets find their way into more under-the-hood applications such as valve covers, engineers are investigating other applications such as fuel rails, intake manifolds, throttle bodies, and water and oil pumps.
Milstar payload delivered
Sunnyvale, CA--Milstar prime contractor Lockheed-Martin recently received the first medium-data-rate (MDR) payload for the next block of upgraded Milstar communications satellites. The military will begin launching the new satellites aboard Titan IV-Centaur vehicles in 1999.
Milstar satellites currently in orbit are Block I. They feature a low-data-rate (LDR) payload supplied by TRW Space and Electronics that transmits information at 75 to 2,400 bps. The new Block II spacecraft will carry both an LDR payload from TRW and an MDR payload to extend the satellite's data-rate transmit/receive capability to 1.544 Mbps. Delivery of the MDR payload, built by Hughes Space and Communications Company, represents a transition to the Block II configuration.
The new payload carries two specially designed nulling antennae that can pinpoint a jammer's direction and temporarily block, or null, signals from that direction. Jam-free operations can be continued in other directions without losing communications.
Milstar's "Switchboard-in-the-Sky" approach uses five technologies not found in previous military satellite communications systems. These are:
The satellite's ability to frequency-hop across its full 2-GHz bandwidth--a first for communications satellites--also enhances security.
Tensioned spokes redefine the wheel
Wilton, CT--Bicycle enthusiasts and racers have something new to spend their money on: compression-molded carbon-composite wheels with spokes that suspend the wheel hub in tension. The design results in enhanced lateral rigidity and the ability of the wheel to protect the rider from shock, says Spinergy Inc.
Making the family of rev-X® wheels involves a three-step procedure, says Raphael Schlanger, engineering manager at Spinergy. First, the rim, all eight spokes, and a hub-flange area are molded as one integral unit. (The multi-layer layup uses both woven and unidirectional carbon fiber.) Next, a rim of 6061 T6 aluminum extrusion, rolled and joined at the ends, is bonded to the composite rim.
Last in the sequence comes hub bonding. "After the rim is bonded up, you have four spokes coming down on each side," Schlanger explains. Each set of spokes comes together at a hub flange. "We pull on those two hub-flange areas, spacing them apart from each other along the axis of the axle. Then you put your hub in there, and lock the wheel in the stretched position." This procedure puts the spokes under a tensile load.
The tensioned spoke system results in a number of benefits, according to Schlanger. Most carbon-fiber wheel designs now in use employ compression-spoke wheels. A compression spoke functions like a column under a compression load. Shock caused by a bump or other obstacle travels through that spoke, through the axle and bicycle frame, to the rider.
With a tensioned spoke wheel, shock may reduce tension in the spoke, but the spoke does not go into compression. Instead, all of the other spokes take up tension to compensate. This design "distributes shock throughout the whole wheel," Schlanger explains, "which means you don't have to make any one part of the wheel exceptionally strong because the impact affects the whole wheel and the design distributes the load throughout the wheel. So you can make a lighter wheel."
In addition, because the carbon fibers are in tension, the design makes the structure stiffer and enhances the wheel's lateral rigidity. A compression spoke wheel requires "a whole lot of material and a lot of section, particularly at the base of the spoke near the hub, to achieve any kind of respectable lateral rigidity," asserts Schlanger. Compression also forces the composite's resin to carry load. But tension loads use the fiber in an optimum way.
Given that pairs of rev-X wheels cost from $750 to more than $1,000, what do they offer a rider, aside from clever engineering? "There's a definite aerodynamic benefit," says Schlanger "The rim cross section is teardrop shaped; it's much deeper than your standard rim. There's much less flow separation as the rim moves through the air." He says that the wheel develops less than half the drag produced by a conventional wire-spoke wheel. "Bike racers might ride several hundred miles a week. And when they ride these wheels they notice the difference."
Flat panel directly replaces CRT
Los Gatos, CA--Measuring five inches deep, this 12.1-inch plug-and-play graphics monitor, called the VueStationTM, supports 256K colors with 800×600-pixel resolution (SVGA).
Made by National Display Systems (NDS), the panels use the firm's proprietary SmartSync technology to translate analog VGA and SVGA signals to a digital format. SmartSync employs an interface board with features that make the flat panel behave like a conventional CRT monitor, according to NDS's Hai Nguyen. In this design, a microcontroller based on an Intel 8088 microprocessor manages the signal going in to drive the flat panel. According to NDS, SmartSync makes the flat panel as easy to use as a standard multi-sync monitor.
In addition to saving space, VueStation consumes less power than a CRT. "A CRT consumes about 35 to 40W, this guy's only going to consume 10 to 15W at the most," explains Nguyen. Unit price for the 12.1-inch SVGA model is $2,300.
Plain plastic bearings weather bumps, sand, and sea water
Costa Mesa, CA--Imagine completing a 2,000-mile bicycle tour without ever hearing that annoying gnash emanating from the front hub. Plain plastic bearings employed in the front wheel hub, headset, and bottom bracket of RBH Machine's commuter-style bicycle reduced the number of parts, cut costs, improved reliability, and simplified maintenance, say company engineers.
Failed bearings on long bike treks mean scored rolling elements, galled races, or maladjusted cones. And if you're a tool-packing biker carrying spare parts, it means roadside greasing and adjustment that often results in sifting sand for balls dropped during reassembly.
Front wheel hubs, steering mechanisms, and pedal-crank mechanisms traditionally employ ball bearings. Engineers generally consider plain bearings, especially plastic plain bearings, unsuitable for these applications because of load limitations, high clearances, and increased friction. Iglide oil-free bearings from Igus Inc., East Providence, RI, have changed the way bicycle designers think.
The Iglide L1 plain bearing design consists of glide pads connected by thin film hinges. L1s contract and expand, maintaining close tolerances under wide temperature and humidity ranges. "Friction has simply not been a problem in this application," says RBH Machine's Richard Harvey. "There is no noticeable difference between Iglide L1s and ball bearings."
Igus supplied off-the-shelf L1s to RBH Machine, and Harvey simply cut them to length. The design, tested on a 30-bicycle fleet, has patent applications filed for the front hub and bottom bracket designs. "We purposely drove the bikes into curbs, on the beach, through salt water, and on dirt trails," says Harvey. "Several bicycles have over 2,000 miles on them without any sign of bearing wear."
Harvey estimates that using L1s saved $20 per headset and is so satisfied with the bearings' performance that he gives a lifetime warranty on Iglide-equipped bikes.
Plastic layer fights graffiti
Baltimore, MD--By placing a layer of DuPont's Tedlar® PVF film over maps and other signage, Globe Transportation Graphics protects the signs from graffiti. Mass transit systems in Maryland and Virginia use Globe Transportation's TransGrafix® signage and markings, which combine high-contrast colors, low-glare finish, raised letters, Grade 2 Braille, and other tactile features.
TransGrafix products employ a top layer of Tedlar TUT10BG3 fused to a subsurface printed polycarbonate substrate. Globe Transportation Graphics then embosses the structure with tactile features and coats its back surface with a high-performance foamed pressure-sensitive adhesive.
Globe Transportation allowed ballpoint pen ink to dry on Tedlar for 24 hours. All-purpose cleaner removed the ink. Samples of Tedlar exposed to a 10% solution of room-temperature hydrochloric acid for one year remained undamaged, according to Duke Zimmerman, Globe Transportation's president.