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
Billy Joe of PFI Fashions Inc. By now, we are all aware there is a PPE shortage for many of the workers who need protective equipment the most. One of the most talked-about items are masks. We are also hearing how many companies are experiencing an extreme decline in business. A local company, PFI Fashions Inc., took what could be a negative situation and used their open capacity to make a very positive impact on their local community. Jodie and Billy Joe Todd, owners of PFI, took it upon themselves to begin manufacturing masks for those in need. Located in Genoa City, WI the full-service company specializes in screen printing, promotional products, and embroidery. Within the course of a week, they have completely shifted their production focus to making washable, cotton face masks. They have been generously donating them to Aurora Hospital, local EMTs, and the other essential workers who need them the most. Because of their hard work, we were able to purcha
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
Customer – IAM Robotics IAM Robotics, creators of the world’s first autonomous mobile manipulation robot, has found a niche in e-commerce order fulfillment. Its robots use highly advanced computer vision and perception technology combined with an articulated robot arm on a mobile base to autonomously navigate warehouse aisles, picking and transporting products just like a human. Our Task IAM Robotics turned to us for our polyurethane expertise. The company tasked us with the job of providing a wheel material suitable for the typical usage and environments of their mobile picking robots, named Swift TM . The company designs their robots to work around the clock, continuously moving on the floors of warehouses and distribution centers. Its charging system only requires a 30-second change about once a shift, avoiding any lengthy downtime. The continuous operation made localization a key consideration when selecting wheels for the Swift robots. The Swift ™ Robot Swi