Field of Springs

In the same city where Astroturf made its debut, another material technology Wrings Houston a new baseball marvel.

When the Houston Astrodome, baseball’s first indoor stadium, opened in 1965, it had a natural grass field. The grass required a translucent roof, which produced glare and caused fielders to lose track of fly balls. To solve the problem, the stadium’s roof was painted and the grass replaced with the newly invented artificial surface that we now call Astroturf.

No matter what you think about baseball on artificial turf, it is commonly agreed that Houston was at the forefront of baseball stadium innovation in the ’60s. It continues that tradition today. The Astros still play ball under a roof but only when necessary. That’s because the city erected Enron Field, a stadium with a retractable roof that makes natural grass possible. Although Enron Field is not the first stadium with a retractable roof, it does boast a special suspension system that is engineered to open and close the roof without glitches.

Bart Riberich, vice president of engineering at Uni- Systems, the Minneapolis-based firm that designed the roof travel mechanism, says that operating problems occur when the suspension system relies on bogies. They concentrate the load at a single point when the wheels hit a high spot on the rail, thereby thwarting smooth movement. Instead of bogies, Uni-Systems engineers turned to independent suspensions for each of the 142 wheels that carry the three huge roof sections atop Enron Field. To make the independent suspensions work, the engineers needed a suspension spring that would compress when the wheels met a high spot on the rail.

Finding the materials to make the springs was about as easy as hitting a Randy Johnson fastball. Almost from the start, Uni-Systems eliminated conventional metal springs because they couldn’t achieve the targeted 25-year lifespan. The designers turned their attention to elastomers, which are not only highly resilient and durable but also able to handle heavy load capacity.

The Uni-Systems design team, along with engineers at Kastalon Polyurethane Products, Uni-Systems’ partner on the project, selected Adiprene urethane prepolymer from Uniroyal Chemical to make the springs. “The springs had to be compact to make the design work,” says Bruce DeMent, president of Kastalon. “The versatility of Adiprene urethanes allowed us to compound an elastomer that would give us the required performance.”

The patented cylindrical springs installed at Enron Field consist of alternating layers of steel and urethane around a central shaft. Only 8 in. in diameter and 9 in. tall, the assemblies support a normal load of 125,000 lbs and peak loads up to 325,000 lbs. Now, the Astros can play ball come rain or shine.

More information on polyurethanes is available by contacting Kastalon Inc. , 4100 W. 124th Place, Alsip, IL 60803 or calling (708) 389-2210.

Fork-Kushions® – Siding Manufacturer

Challenge/Problem/Issue
A quality control supervisor of a globally recognized manufacturer of engineered wood siding was continually experiencing significant damage caused by their forklifts picking up bundles of siding. Unique to the industry, their siding boards are denser and more rigid than traditional strand board siding, however, this rigidness also makes the sharp edge more susceptible to damage when coming in contact with the back of a lift truck. As a result, the supervisor searched for possible solutions.

Solution
Upon investigation, the supervisor learned of a revolutionary forklift bumper system called Fork-Kushions® that had proven to provide impressive damage control. Due to the sharp edge of the siding, it was determined that the “cut-resistant” style with its durable outer surface and it’s shock absorbent center would be the best fit to test against their application.

Customer Value
After 2 weeks of putting the Bumper into service they saw a 30% reduction in Broken Board. There was also a reduction in Siding interlocking with itself when the forklift picked up the tiers of newly milled siding. Although this was not a defect, it did cause safety and ergonomic issues and was greatly reduced by using the bumpers. The only concern they had was that they were going to have to purchase a longer fork for the forklifts to make up for the 1-1/2″ they lost for the bumper and it’s bracket.

After a full 3 months in service, the Fork-Kushions combined with the hydraulic carriage dampers for the fork lifts resulted in about an impressive 60% reduction of in process damaged board.

Sound Value Being Added to the Workplace

In 1987 society was introduced to a relatively new term called Ergonomics. By definition, the new buzz word means “The study of workplace equipment design or how to arrange and design devices, machines, or workspace so that people and things interact safely and most efficiently.” Countless organizations were formed and research groups began delving into the cause, effect and corrective action required to reduce the occupational injuries associated with the work environment.

As a result of studies and analysis done in the workplace, jobs have been made more efficient, less fatiguing and safer for the employee. OSHA has established a comprehensive strategy and has written a protocol for Developing Industry and Task Specific Ergonomic Guidelines published in June of 2004.

As we continue to search for ways to recognize and control potential hazards in the work place, nearly twenty years later, the newest safety concern to be brought to the forefront is Noise in the Workplace. Noise is often overlooked as a key “ergonomic” element in the workplace, however, the National Hearing Conservation Association has proven otherwise and has formed an alliance with OSHA to develop a hearing conservation programs that can be adopted by industry.

Studies have proven that excessive noise can cause lasting damage to hearing and can be considered dangerous if an employee is exposed to sound levels of 85 decibels or more for prolonged periods. Further, occupational noise has been written into General Industry Safety Orders for many states and has been named to the top 10 OSHA citation list with fines totaling over $206,000 in 2002.

According to OSHA’s 1981 estimates, at least one million workers in manufacturing and utilities had sustained occupational hearing impairments greater than OSHA’s definition of hearing handicap.

Unfortunately, although loss of hearing is the second highest self-reported workplace injury or illness in the United States, it is considered to be 100% preventable.

As automation continues to revolutionize industry, more and more facilities have integrated a material handling conveying system into their work flow in order to move product more efficiently. A conveying system not only brings an efficiency factor but adds an additional noise factor, as well. In conveying environments noise is created by not only the machinery itself, but also the product being conveyed across the belt or metal rollers. In addition, noise can be accentuated by conveying systems being operated at higher speeds.

According to a report published by the Conveyor Product Section of the Material Handling Industry “The primary goal should always be to reduce noise at its source.”

Different conveyor designs create different noise issues to be dealt with. For example Roller tube ringing is a common source of noise in roller based conveying systems. By covering metal rollers with Kastalon Koat-A-Roll® polyurethane conveyor roller sleeves , the roller surface is transformed to a non-marking, shock-absorbing, rugged “slip-on” polyurethane coated conveyor roller. Product is now transported across the urethane material and does not come in contact with the metal roller. Independent field tests have found that simple addition of polyurethane sleeves results in an impressive reduction in operating noise measuring 7-10 decibels.

Benefits of Koat-A-Roll®
Utilizing innovative components such as Koat-A-Roll® conveyor roller sleeves, legacy systems can be retrofitted in the field with inexpensive non-marking, rugged “slip-on” polyurethane roller covers. The value is not only limited to immediate reduction in noise, but the cost effectiveness becomes even more substantial when considering the greater friction and longer component life that is achieved.

For more information about Kastalon Polyurethane Products, visit www.kastalon.com or contact their client relations staff at 800-527-8566.

Polyurethane Is A Perfect Fit For Pipe And Bar Straighteners

Pipe and bar straighteners are a great market for polyurethane parts for noise suppression, product protection and conveying. Kastalon has supplied this market place with many parts on an MRO basis. We have developed a material that has the impact resistance, cushioning and enhanced wear resistance required to provide the optimum in life for a trough liner.

We would recommend using material thicker than 3/4″, generally 1-1/4″ to 2″ thicknesses is ideal. The liner will function properly until it is worn through. Some additional positions that could and should be polyurethane/plastic covered are:

  • Protective Pads: (shock absorption, noise suppression, cut, tear and abrasion resistance, product protection)
  • Kicker shoes (these are the arms that pick up and push or kick the tube/pipe/bar, down the ramps).
  • Transfer arm covers (similar or the same as kicker arms, they also may be a wheel moving the pipe from one conveyor to the other)
  • Any hard stop surfaces for the pipe
  • V Rollers for roller transport (better friction and drive than plastic)

Kastalon produces a highly engineered a polyurethane compound in 75 Shore D hardness that is extremely effective in protecting the pipe surface and has a very long life. We find these straighteners mostly in solid bar plants where shafting and forging stock have very critical surface finish requirements (to prevent stress points in the surface of the bar which lead to cracks)

Any where there is shock, polyurethane due to its elastomeric nature, including in plastic hardness, is more effective and long lived than plastic.

Polyurethane improves safety in mills

In a steel or aluminum mills, safety is always a major concern. With many employees staying in the workforce longer, there is a growing concern for reducing injuries that result from heavy lifting.

Recently, an aluminum mill established a goal to limit the maximum weight lifted manually at 50 pounds. In the roll shop this was a major concern because the bearings are held in place by a large steel split ring, known as a thrust collar that is locked into place. The maintenance process of changing out the bearing requires the worker to break the ring free and remove it. These rings can typically weigh more than 60 pounds each.

Interestingly, Kastalon was able to design a custom engineered polyurethane alternative that had all of the same strength and wear characteristics of the steel ring, but only weighed 12 pounds.

The first 4 rings well exceeded the life expectancy by lasting more than a year in continuous service and proved to reduced lost time due to back injuries in that area.

Not only did the mill find a method that would protect their workforce from unsafe practices but also found a way to achieve greater efficiency.

If you would like to learn more about our metal processing solutions, contact Lyn Thorne at lyn@kastalon.com.

Designing Rollers – Kastalon helps companies save by joining their design team!

When designing a roller assembly it is critical to take into consideration the actual application and environment that rollers will be operating in. Although the drawing might be accurate, it is essential to involve your roller manufacturer in the design phase to assist in choosing the right polyurethane compound that the roller will be covered with. Not all polyurethanes are the same, but understanding how the roller is going to be used and where the roller will be located, is essential in choosing the right material that will result in the best performance.

To avoid over engineering a roller assembly, which can affect the cost and lead time, the roller manufacturer can help choose the proper material with adequate tolerances for the specific application being planned. For example, calling out a very tight tolerance can drive up the cost of the roller unnecessarily.

This is where Kastalon can help.

Recently, a customer gave us a drawing for a new roller assembly for a new process. The engineers called out a TIR of .005. After several months of receiving the rollers as requested, they sat down with us and shared their concern that the cost of the rollers was negatively impacting their ability to sell their new system. Once they shared the actual application and environment with our design engineers it was determined by opening up the tolerance to .015, the cost could be reduced by more 20% with no effect on quality, life expectancy or system efficiency. The lead time was also significantly reduced and the outcome was the customer’s ability to deliver their new system at a lower cost and a reduced lead time.

We like to think that having us on your design team is a win, win proposition!