Behind the Wheel is a blog created by Stellana for the wheel industry. Whether you are new to polyurethane wheels or have been in the business for a long time, this blog is a great tool for polyurethane education, industry safety, company news and updates, and much more.
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Quality | Understanding & Reducing Hysteresis
Understanding and Reducing Failures:
Polyurethane is one of the most versatile materials.1 Physical properties can be adapted to solve challenging problems. Polyurethane
is formed by reacting a polyol (ether-based or ester based) with an isocyanate
(an MDI or TDI). It is then cured at a specific temperature for the optimal
time to reach desired physical properties. Properties are altered based on the
polyol and isocyanate and the application impacts the function. It is critical
to choose the ideal material based on the application and the conditions the
product is expected to withstand.
What is Hysteresis?
Hysteresis is a time-based dependence that relies on present and past inputs. Polyurethane is an excellent insulator and absorbs and stores energy,
which will then be converted to heat. If heat generation is greater than heat dissipation,
the polyurethane will melt internally, resulting in a buildup in pressure as
the material expands. The increase in temperature will change the physical
properties of the material. Evidence of
hysteresis can be indicated with a powder like substance, bumps on the tire, or
visible molten material. The most common causes of hysteresis are overloading
the part or operating at too great a speed.
Contributing factors to heat buildup in tires include: poor
conductivity of polymers, tread thickness, size of tire, speed of rotation,
load on tire, TIR of tire, and length of run. Improper installation- metal hub
rubbing on other metal object causing friction will generate heat.
Metal objects imbedded in the tire promote heat generation.
In the picture, a metal object is imbedded in the tire. The metal will absorb heat and raise the temperature of the wheel. As a result, the material changed physical properties and burned off the adhesive.
Hysteresis is commonly mistaken for bond failure. What is Bond Failure?
Bond failure is a result of improper surface preparation,
contamination, or machine malfunction. A true bond failure will leave adhesive
intact on the metal. The excessive heat generation in the hysteresis process will burn off adhesive on the poly or metals, or both.
Ways to Avoid Hysteresis
You can significantly reduce costs associated with downtime
and extend the life of your product with the proper conditions of the
application. Decrease speed of trucks, load capacity, or length of runs. Experts
will help you choose the correct system based on the application needs. Engineering experts will review
the design of the tire and optimize the cross-sectional thickness, runout, and
About New Tech Machinery New Tech Machinery (NTM), based out of Denver, CO, is the leading manufacturer of the portable rollforming machines that include seamless gutter machines, metal roof panel machines, and other specialty equipment. NTM transformed the metal construction industry by bringing contractors easy-to-use rollforming solutions directly to the job site. New Tech Machinery was also the first portable rollforming company to commercially produce and market a polyurethane drive roller machine with separate forming rollers. Due to their history of innovation, NTM’s designs are frequently imitated throughout the industry and most have implemented this technology. Wheel Malfunction This machinery is used by contractors and other professionals within the metal construction industry to form metal sheets into rain gutters, metal roofing, siding, and more. NTM was experiencing continual adhesive and bonding issues in the wheels previously used on their equipment
Our Task – Vulkollan Scarcity The material handling industry has continued to face a shortage of Vulkollan wheels and rollers. What is Vulkollan®*? Vulkollan is a cast polyurethane elastomer that is known to offer the ultimate performance under the most demanding applications. The material has gained a reputation for being one of the toughest polyurethanes available, and many members of the industry believe that there are no substitutes for a material of this caliber. Vulkollan® wheels and rollers are widely used on industrial trucks in Europe. Characterized by their dynamic load bearing capabilities and low wear and tear, these products minimize the need for service. Many equipment manufacturers count on Vulkollan products to keep their trucks up and running. At Stellana Sweden, we have a state-of-the-art Vulkollan production line that is dedicated to making Vulkollan wheels. However, we too have had trouble supplying these products. Material Shortage Since
What application comes to mind when you think of polyurethane wheels and tires? I would bet forklifts do for many of you. While a countless number of our polyurethane wheels and tires are used on forklifts, our materials excel within a variety of other applications. Our engineering expertise and manufacturing experience allow us to produce high-quality polyurethane for a variety of industries that you may not have imagined. Stellana is one of the world’s largest manufacturers of molded polyurethane products. Our engineering team consists of mechanical and chemical engineers who have a unique understanding of polymer formation. This department is equipped to tackle product design, tooling, material selection and carry out a variety of performance analytics. Whether it is a new design or one in need of improvement, our engineers find a way to offer the best solution. 7 Surprising Applications At Stellana , we think of ourselves as application specialists because of our abil