Adhesives in the Automotive Industry

Adhesive bond materials are transversal to many different industries: from automotive to aerospace, electronics, medical, sports, and construction. Providing high-performance adhesive to aluminum, steel and other materials, structural adhesives have become an interesting and valid solution to replace welds and mechanical fasteners, helping to improve durability, reduce weight, and reduce manufacturing costs. 

In the automotive industry, reliability and durability are the most important characteristics, and structural adhesives meet these criteria better than most others. For applications in this industry, where adhesives are being used increasingly in safety-critical areas, it is necessary to carefully evaluate any possible decrease in performance that may occur when the adhesively-bonded joints are subjected to impact loading.

Download our white paper Read more

Instron Awarded by the United Way

We are proud to announce that our Community Connection Committee (C3) has been awarded the Campaign Coordinator Award for the fourth year in a row by the United Way of Tri-County. This honor is in recognition of a successful 2013 United Way Campaign to advance the local community through service and support.

The Annual Recognition Event Breakfast was again marked with inspirational stories of courage and overcoming adversity. This year's Special Guest Speaker was Harry Gantz, Co-producer and Director of the film American Winter, a documentary shown on HBO. American Winter is a film that follows the personal stories of families struggling in the aftermath of the worst economic crisis since the Great Depression.

Read more

The Truth About Strain Gauge Load Cells vs. Pressure Transducers

Load cells independently and directly measure the force being applied to specimens. Pressure transducers measure force indirectly from the oil pressure observed in the cylinder. Which is superior? The answer is simple: Load cell technology due to the fact that some of the pressure in a hydraulic system has nothing to do with the load being applied to the specimen.

Design Differences: Left Load cell measures force directly | Right Pressure Transducer measures force indirectly

For instance, moving the cylinder requires some hydraulic pressure to overcome the friction between the piston and cylinder; raising the piston off the cylinder bottom can require a significant amount of pressure; and the weight of the oil itself creates pressure in the system. This pressure creates errors in the indication of load and can raise the lowest calibrated reading (sometimes as high as 10% of capacity). Machines using pressure transducers attempt to eliminate these inherent load measuring errors:

• Systems are designed without seals ... Since piston seals cannot be used on pressure transducer systems because of the frictional forces that would result, hydraulic fluid spills out of the top of the cylinder. Extra drain lines are needed to return the fluid to the reservoir. Over time the overflow can increase as the piston and cylinder assembly wear resulting in decreased testing speeds
• Additional plumbing and fittings are needed to eliminate friction ... Hydraulic bearing pressure and return lines are used to float the piston. Meant to keep the piston from touching the cylinder sides to eliminate friction, it requires more parts, more mechanical adjustments and could possible limit the machines ability to handle off-center loading.
• Electrical pressure offset is required for the weight of the oil in the cylinder ... The pressure reading is affected by the weight of the column of oil. As the piston is raised, the volume and height of oil in the cylinder changes requiring a complex chain and pot assembly to electrically offset the weight of the oil as the piston is moved. Accuracy of the load readings over the entire stroke of the machine is questionable.

When making critical business, design, or process decisions based on the mechanical properties of a material, shouldn’t these properties be measured directly with a load cell rather than indirectly with a pressure transducer?

Download the white paper Read more

Thermoset and Thermoplastic Composites ... What’s the Difference?

As composites continue to be adopted in more industries, fiber-reinforced plastics can be found in products that people interact with every day, including cars and sporting goods. Fiber-reinforced plastics consist of reinforcing fibers surrounded by a plastic matrix. There are several types of fibers that can be used including glass, carbon fiber, and aramid which give the material its high tensile strength. The matrix gives the composite the compressive strength and, in the case of fiber reinforced plastics, can be made using thermoset or thermoplastic polymers.

Thermoset polymers are polymers that are cured into a solid form and cannot be returned to their original uncured form. Composites made with thermoset matrices are strong and have very good fatigue strength. They are extremely brittle and have low impact-toughness making. They are commonly used for high-heat applications because the thermoset matrix doesn’t melt like thermoplastics. Thermoset composites are generally cheaper and easier to produce because the liquid resin is very easy to work with. Thermoset composites are very difficult to recycle because the thermoset cannot be remolded or reshaped; only the reinforcing fiber used can be reclaimed.

Thermoplastic polymers are polymers that can be molded, melted, and remolded without altering its physical properties. Thermoplastic matrix composites are tougher and less brittle than thermosets, with very good impact resistance and damage tolerance. Since the matrix can be melted the composite materials are easier to repair and can be remolded and recycled easily. Thermoplastic composites are less dense than thermosets making them a viable alternative for weight critical applications. The thermoplastic composites manufacturing process is more energy intensive due to the high temperatures and pressures needed to melt the plastic and impregnate fibers with the matrix. The energy required makes thermoplastic composites more costly than thermosets.

These two similar materials have such different properties that both will continue to be used in different applications for very different reasons and the products of the future will likely be a combination of both.

Read more

Testing United States Bridges at Columbia University

With recent events causing concern about the stability of major bridges, the Department of Civil Engineering and Engineering Mechanics at Columbia University is evaluating their durability with the help of Instron. Click to watch the video:

 

The Robert A. W. Carleton Strength of Materials Lab discusses with CBS News how they are testing timeworn infrastructure in the United States to understand how they may react to various scenarios. Read more