What are the major trends in adhesives used to bond metals?
This part of the industrial field has mostly the same trends as other adhesives: faster, stronger, and cheaper. Customers want to make parts faster, and they want them to be more reliable. And everyone wants to cut costs.
Are there any new markets emerging?
One new aspect is that people are looking for more structural adhesives that will support heavy loads and can have exposure to heat, humidity, or chemicals. Adhesive technology is starting to catch up to the requirements in this field. We're producing single component products that are much simpler to use than technologies with two components in two bottles that were sensitive to application techniques. The new adhesives can save customers both time and money. Structural adhesives represent large volumes; some replace welds that are a foot in diameter. There are also areas in home construction such as metal truss beams that once had around 100 fasteners. The majority of the fasteners have been replaced by adhesives. But adhesives can't yet withstand the temperatures of a house fire, so some screws must be used to prevent a collapse if there is a fire.
How are adhesive costs changing?
When you look at high volume adhesives like construction, it has to be cost effective. It comes down to labor versus product. The labor costs for someone to insert screws or weld the metals can be very high. Adhesives are not always the cheapest option. But a lot of time people look at the price, sometimes $100 per pound, and they don't realize that they'll only use a fraction of a gram for each bond. In terms of replacing fasteners, we eliminate the cost of carrying various size fasteners, and you don't need lock washers.
What's changing in adhesive curing?
Curing speed is always a fine line. People always want it to be faster, but it can be too fast, setting up too quickly. For example, if a production line moves slowly and the adhesive is fast, you'll have a problem with waste. But if the line moves slowly and the adhesive is fast, you might have parts falling off as they move down the line. You have to look at each application as unique and balance the factors. In other applications, you can end up throwing out a static mist tip if the adhesive sets up too quickly. The tips can become clogged if materials set up in the dispensing tip before they're used.
How is the business side evolving?
Equipment integration has become a key part of the entire system sell. We're now looking not only at the adhesive but also the lab services to qualify it and the equipment to apply it. Adhesive companies are offering total solutions now, from cartridge guns all the way up to multi-million-dollar work cells. Adhesive companies used to be very limited in what they would offer. Manufacturers are also putting much more emphasis on quality. Depending on the industry, defect rates can be 20 parts per million. In automotive, they're trying to get below 1 ppm.
Ed Fisher is a senior applications chemist at Henkel Corp.'s Loctite group, where he's worked for the past 11 years. He holds a Bachelor of Science degree in chemistry from the University of Connecticut and has an American Chemical Society accreditation. His current responsibilities include adhesives and design support for the appliance and military markets.