Quality | Understanding & Reducing Hysteresis

-

Understanding and Reducing Failures: Hysteresis

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 surface area.

Amanda Coca
Quality Manager at Stellana US

 References
1. https://polyurethane.americanchemistry.com/Introduction-to-Polyurethanes/

Comments

Post a Comment

Popular posts from this blog

Customer Success Story - New Tech Machinery

-
Image
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
Read more

Stellana Developed Powerthane® Plus as replacement for Vulkollan®

-
Image
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
Read more

Is eCommerce affecting ordering patterns throughout our industry?

-
Image
How many days a week do packages arrive at your household? For some of us, you could even ask how many times a day do packages arrive at your house? Buying habits and expectations have been changing for some time now, and these trends are forcing warehousing and manufacturing operations to adapt. There is little to no room for downtime, and forklift wheels and tires play a crucial role in keeping things moving during the seasonal peaks and shopping holidays such as Cyber Monday. Current Climate in the World of Ecommerce Ecommerce trends are making order fulfillment more complex. In general, consumers are placing smaller orders more frequently. With the ease of online ordering, it is not unusual that someone places an order, then a few hours later, places another order with an additional item they forgot. With a just few clicks, a passing thought can become a purchase. Seamless operations provide the ultimate convenience for the purchaser, but behind the scenes with each ord
Read more