MANUFACTURING TECHNOLOGY
Speciality resins enhance fastener systems By Mark Thurber, CEO at Maelstrom Chemical Technologies LLC When designing new, innovative componentry or sub-assemblies, one must eventually consider the seemingly ordinary topic of attachments. More often than not, all the parts that comprise the assembly can be brought together and held in place with all the usual suspects: Screws, bolts, pins, clips and the like.
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his practice is all well and good until one encounters the dreaded semi-permanently or permanently hold parts together exception – where conventional hardware simply will not work while in transit. For example, bolts needing separate on its own. We frequently hit this ‘bump in the road’ for the same accessory parts, such as multiple washers, bushings or half dozen reasons such as: No viable access, a poor anchoring spacers, may be held together and staged upstream to site, incompatible process steps, poor geometry, costing or ‘due to speed up assembly. A resin ring affixed to the side of the bolt a last minute design change we did not properly consider the can hold these accessory parts in place attachment point, but now it’s too late to modify the tooling so while in transit, making the bolt its own we had better figure out something fast’. sub-assembly, fully ready to be installed Complicated situations don’t always require complicated upon arrival. answers; they may only need one: A multidimensional An almost opposite case can exist approach or a ‘composite’ solution. The pecking order for where the bolt itself may need to be attachment options includes a multitude of mechanical choices, retained in a receiving hole of a much primarily because they are tangible, as well as easy to see and larger component, such as a valve cover, understand. Only once this array of choices is exhausted, manifold, chassis or bracket. A well placed either by mechanical rationale or cost, do we look beyond to polymer retainer can capture fasteners in the less defined, more ethereal options of reactive resins and a ready-to-drive position. related materials. In other examples, a complex Tectorius® Tec-U-Seal™ Not always considered is the fact that mechanical and polymer system can replace a metal or chemical attachment techniques need not be regarded as plastic retaining clip entirely. Where mutually exclusive. Often the optimum outcome can be fixturing implements were once needed accomplished by bringing together the best attributes of to instantaneously hold assemblies in multiple materials into one item. position while adhesives dried or cured, Anchoring systems used in concrete or masonry these may now be replaced by instant applications have long looked to epoxy products to enhance fixture adhesives. Traditional, UV cured the performance of the imbedded anchor. Although the anchor instant adhesives have had the drawback itself is intended to carry the load, the epoxy fortifies the of not being able to be cured where light surrounding concrete, dampens vibration, prevents water cannot penetrate or where the deposit intrusion and prevents torsional shifts; ultimately providing a is too deep for the light to reach the full more durable, long lasting connection. deposit depth. Tec-Stay™ Minutefix™, Resins and polymers can be ideal complements to metal a new groundbreaking addition to the Tec-Stay™ components in joint designs. Threadlocking adhesives have Tec-Stay product line, addresses this been commonplace for many decades as a means of securing very challenge. bolts and screws. In more recent years, the use of new resins has expanded the Often times, processes, adhesives or coatings must be possibilities for single component fasteners to perform multiple added functions, applied to products, such as in electronic components, where all while doing their primary job of securing a joint. extensive time is required for the final article to cure. In many One example includes Tectorius® Tec-U-Seal™, a formed-in-place polymeric scenarios, mechanical fixturing is employed to hold parts in material that is positioned under the head of common bolts and screws, and limbo, sometimes for days, while the final cure takes place. The used to seal, cushion, or retain parts in multi-staged assembly. Tectorius Tec-Stay Minutefix product line is UV cured, allowing Tec-U-Seal brand encompasses a number of different product grades for a wide for instant bonding, dry to the touch texture and is range of application types and provides reliability, corrosion prevention, as well self-fixturing. Areas that are too thick for the light as streamlining the assembly process. penetration or shielded from the light will continue to cure for Retaining by use of resins does not stop at concrete anchors and epoxy. several hours thereafter, while being held and sealed securely. Specialised multifunction resin systems can be modelled to serve a wide range of Advances in resin systems cleverly coupled with functions and add versatility to fastening systems. Retaining, anchoring, fixing, conventional mechanical methods, can greatly expand fixturing or staking can make huge strides in assembly line efficiency. Precisely the engineering and assembly toolkit for product and placed polymer resins can be designed into processes where they temporarily, process optimisation. info@tectorius.com
148 FASTENER + FIXING MAGAZINE // ISSUE 115 JANUARY 2019