Jim, Tom, and Dave: Thanks, guys, for the detailed feedback and your collective experience. The advantages of one over the other obviously depend on the specific circumstances. The big advantage I kept hearing about adhesives was simplification and therefore reduction of manufacturing times, thus savings. I will keep all this in mind when I work on the micro-fastener feature. Your feedback will help me ask better questions!
Jim makes a good point. Adhesives can resist as much load as mechanical fasteners -- provided that you have enough surface area to spread them over. But since, in round numbers, the shear strength of steel is 100 times greater than the shear strength of typical structural adhesives, this means you need to have 100 times more surface area. It might not be hard to find this much surface area on a large component, but on a small component, it could be a challenge.
Where adhesives really shine is in fatigue -- and since, in my experience, most fastener failures are fatigue failures, this can be a big advantage. Also, as Tom Drechsler points out, if adhesives are properly used, they can vastly simplify a manufacturing process.
Given all this, I would imagine we will see more and more adhesives on our products. Are there particular industries that are adopting this? Are there certain industries in which the adoption of adhesives is a particularly strong solution?
Rob, the cost differential seems to revolve mostly around application process differences that save manufacturing costs and time, which also translate into cost. But your point is well taken--if the adhesives help the product last longer since it's not poking holes in sheetmetal--which will make the metal fail sooner as well as creating a point of ingress for damaging liquids--then that's another cost savings.
Ann: We were able to reduce the cost of a small shaft assembly by eliminating machining operations for traditional fasteners by switching to an anaerobic shaft-locker. The resulting bond is stronger than the small 17-7Ph shaft it is used on. Surface prep is critical, dispensing must be done carefully but when done in a controlled environment with fixturing the assembly times can be managed. Life & overstress testing has validated the process and we continue to monitor it as this is new ground for us.
The resulting parts are stronger (no flats for stress raisers), have less vendor issues (deburring on fine ID bores from cross threading or stepped shaft diameters). and take less space (even small fasteners have length requirements that conflict with highly packed components).
I've experienced the opposite problem. In fact experiencing it now. When attempting to fasten small components with adhesives, there is less margin of error. Less surface area, more opportunity for contaminant, or surface irregularity to confound adhesive. I guess there are some caveats - such as surface preparation, use of cleanroom, etc. Sometimes you simply want there to be a "mechanical" connection.
Chuck, that's an intriguing point about adhesives replacing fasteners in ever-shrinking smaller electronics. That's what I would have thought, but it turns out there's a "micro" class of fasteners that are ridiculously small--I don't recall the exact dimensions--and that will be the subject of an upcoming feature this year.
Dave and Alex, thanks for the feedback. A whirlwind tour it was. Each of these subjects deserves its own feature, and in fact, each will get its own spot at least once again this year. I concentrated on structural solutions since those seem like the toughest area for adhesives to beat fasteners, but they came closer than I'd initially expected. The fact that adhesives spread out the load over a larger area seems to be one of their biggest advantages. Pretty awesome numbers, eh? There's a lot more going on with adhesives, and they've come a lot further, than I would have guessed.
Interesting, Ann. It could be that the material costs are small compared to overall costs. If the adhesives are particularly effective, there could be additional savings in quality through the life of the product. That could matter in terms of overall costs.
I would think that adhesives offer an advantage in smaller electronics partially because mechanical fasteners can only get so small before they become a manufacturing problem. I would imagine that some of today's razor thin phones would be a good example of this.
For 3D printing to make the jump from rapid prototyping to manufacturing, engineers will need to find easier ways to move products from their CAD screens to their printers.
Gigabit and PoE are two networking technologies moving ahead in tandem as industrial users power remote Ethernet devices such as IP security cameras at 1,000 Mbps over existing CAT5 cable.
New versions of BASF's Ecovio line are both compostable and designed for either injection molding or thermoforming. These combinations are becoming more common for the single-use bioplastics used in food service and food packaging applications, but are still not widely available.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 5
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
2 
