Easier Bonding for the Tough Combinations
Laurel and Hardy. Lewis and Clark. Some combinations just seem to go together. Aluminum panels and steel tube framing. Oak veneer and particleboard. Flexible foam and an ABS part. To readily bond these and many other combinations of high surface energy or porous materials, you have a wide selection of 3M liquid, paste, hot melt, and pressure sensitive adhesives.
Other combinations, however, don't seem to go together as well: Oil and water, natural rubber and a polypropylene housing. These and other tough combinations like bonding EPDM rubber to a powder-coated surface, or bonding anything to oily metal without cleaning can be very challenging. But it does not have to be!
In the following articles, see how ongoing 3M innovations are making even the toughest-to-bond applications easier and easier.
Bond EPDM, CR, SBR, and more...now without priming
For the many product designers who consider EPDM, CR, SBR, natural rubber, and other TPV and TPE solids as hard to bond, 3M offers the easy way to bond with liquid, hot melt, and pressure sensitive adhesive choices that best meet production and end use requirements.
If you want instant World Record-type Strength adhesion over a smaller bond area, consider 3M™ Scotch-Weld™ Instant Adhesive PR100 with low viscosity for tight fitting parts, or PR600 with medium viscosity for gap filling. Either way, a simple pinch from a flexible container applies a precise drop or bead of cyanoacrylate power.
When 100% solids, fast bonding, and flow over a larger area are the answer, 3M™ Scotch-Weld Hot Melt Adhesive 3796 gives 40 seconds of open time for assembly, and bonds with one of the highest peel and shear strength combinations in the 3M hot melt line
For bonding EPDM, sponge rubber, or rubber sheeting to most porous surfaces with low soak-in, evaluate 3M™ Scotch-Weld™ Industrial Adhesive 4799. This pioneering formulation dries quickly to a flexible, water resistant bond.
Bond LSE plastics with the strength you need, the ease you want
Low Surface Energy (LSE) plastics can't help but to drive you crazy. It's in their nature.
To illustrate the concept of surface energy, think of water on the unwaxed hood of a car. The unwaxed hood has high surface energy (HSE), and water on the hood flows into puddles. Surface energy ranges from high to low (Figures 1 & 2), and a waxed hood has low surface energy. The water beads up. Similar to water, adhesive on a high surface energy plastic, such as ABS or nylon, flows and "wets out" the surface. "Wetting out" is required to form a strong bond. Most adhesives and tapes on LSE plastics, such as polyethylene or polypropylene, however, have a tough time sticking.
|Low Surface Energy Figure 1
||High Surface Energy Figure 2
That could be a problem for engineers who want to take advantage of the lower cost of LSE plastics as compared to engineering grade plastics. But with 3M, there's no problem at all. You just need to tell us how much bond strength you need in the range from non-structural to structural. Typically, non-structural adhesives bond with less than 1,000 psi, and structural adhesives bond load-bearing parts of a product with strength of 1,000 psi and above.
If you want to bond nameplates and graphic overlays, for example, to polypropylene housings, 3M™ Laminating Adhesive 300LSE Products bond on contact after simply wiping dust off the substrates. Die-cut for a precision fit with high shear and peel strengths, and resistance to chemicals, moisture, UV light, and high temperature. With a 200g load in shear and a half square inch of overlap, 2 mils of one of the 3M™ Laminating Adhesive 300LSE Products holds at up to 444°F.
Other applications include attaching gaskets and cushions, membrane switches, underhood labels, decorative trim, instrument clusters, LCD windows, and assembly of plastic housings.
Select from 2.0 to 7.9-mil adhesive thickness to match the contact requirements of smooth, textured, or rough surfaces. Select specific products from lines of either adhesive transfer tapes or double-coated tapes. The carrier of a double-coated tape adds dimensional stability for handling ease.
At the high end of the strength spectrum, 3M™ Scotch-Weld™ Structural Plastic Adhesive 8010 a 2-part acrylics that bond LSE and HSE plastics with strength greater than the materials joined. In many assemblies, you eliminate the extra processing steps of screws and rivets, avoid the restrictions of plastic welding, and reduce surface preparation to simply wiping off dust or oil.
With a simple squeeze, the 3M™ EPX™ Plus hand-held applicator simultaneously and accurately meters, mixes, and dispenses the 2-part formulation from the convenient 3M Duo-Pak cartridge. Bond quality is consistent, and you eliminate metering guesswork, measuring time, and reduce adhesive waste
Typical applications include assembly of a thermoplastic composite railing, bonding a polypropylene/EPDM alloy gasket into a swimming pool diverter valve, assembly of multi-layer polyethylenesignage, and securing urethane rubber end caps into the bodies of polyethylene batons.
3M™ VHB™ Tape 5952 offers the speed and convenience of a pressure sensitive adhesive with strength enough to replace rivets and screws in many applications. It bonds high and low surface energy plastics to themselves and many other substrates. The white, closed cell acrylic foam carrier provides viscoelasticity to absorb impact, damp vibration, and flex with differential thermal expansion and contraction.
Whatever your production considerations, budget, and end use demands, Think 3M First for LSE plastic bonding. In addition to what you've read so far, think about 3M™ Quick Bonding Adhesive 360 Products -the thin laminating adhesive that bonds at the speed of touch and outperforms many thicker adhesives; 3M™ Scotch-Weld™ High Performance Industrial Plastic Adhesive 4693 - LSR bonding from a collapsible tube dispenser; 3M™ Scotch-Weld™ Hot Melt Adhesives 3731 and 3764; 3M™ Scotch-Weld™ Instant Adhesive PR600 & AC77 Primer; 3M™ Hi-Strength 90 Spray Adhesive; and more.
Oily or powder coated metals...not so tough anymore
Bonding to oily metal
Used to be you had to take the time and effort of removing light oil from metal before trying to bond anything to it. Now with 3M, you've got non-structural and structural choices that bond as if the oil isn't even there, saving you time and money.
In addition to bonding LSE plastics (see above), 3M™ Laminating Adhesive 300LSE Products bonds plastic nameplates, metal rating plates, die-cut rubber or felt gaskets, foam cushions, graphic overlays and appliqués, film labels, and more to lightly oiled metal without surface preparation.
For the many designers who want thinner bond lines for thinner products using lighter weight materials, 3M™ Quick Bonding Adhesive 360 Products provide more strength with less adhesive on more substrates, including lightly oiled metal. With a 2-mil or 5-mil transfer tape or a 2-mil or 4-mil double-coated tape using 3M™ Quick Bonding Adhesive 360, shear and peel strengths are equal to or greater than thicker tapes. Even though thin, the neat, dry adhesive conforms to textures to bond and seal even against solvents and typical household cleaners. For success in electronics, appliances, medical devices, and other market application involving exposure to heat, it can resit up to 350°F. That's enough to reliably withstand the heat from an electronics transformer.
For structural strength bonding, 3M™ Scotch-Weld™ Toughened Epoxy Adhesive DP920 cuts through surface oil and cures at room temperature, saving the cleaning and energy cost of heat. Wherever metal meets metal in agricultural equipment, appliances, elevator panels, construction equipment, trailers, and millions of other products, toughened DP920 increases bond line durability for long-term rugged use.
Overlap shear strength of 4,400 psi and an average T-peel of 21 piw combine to be one of the most powerful adhesives in the 3M line. No order associated with structrual acylis.
Bonding to powder-coated metal
Powder coating is applied electrostatically to metal and heat-cured to form a protective and decorative layer that's tougher than conventional liquid paint. Metals such as aluminum or stainless steel are high surface energy (Figure 2 above), but once the metal is powder coated, you will be bonding to a low surface energy "skin". You have three 3M choices in pressure sensitive adhesives depending on how much holding power you want. For bonding lighter weight materials to powder coated metal, you've already read above about 3M™ Laminating Adhesive 300LSE and 3M™ Quick Bonding Adhesive 360 Products.
Metal Surfaces (High Surface Energy) Figure 3
For higher holding power in static and dynamic loads, 3M™ VHB™ Tape 4941 replaces mechanical fasteners in such applications as bonding powder coated metal stiffeners in office desks and filing cabinets.
Now bond the really tough one without priming
Silicone repels and makes a great gasket for keeping out water and solvents, even in very high heat environments. The problem for product and manufacturing engineers, however, is that silicone also tends to repel adhesive unless primed. At least, that's how it used to be.
3M™ Silicone Laminating Adhesive Transfer Tape 91022 and Double-Coated Tape 96042 bond silicone rubbers and foams to themselves and to other substrates on contact without priming. High shear strength, good peel strength, and high solvent resistance combine for success in such applications as gasketing, flexible keypad assembly, Buzz/Squeak/Rattle control, and splicing silicone liners.
The 3M adhesive resists up to 500° F for high heat applications such as brake shim bonding. The polyester carrier in double-coated tape 96942 resists up to 300°F.
Both tapes feature a single 2-mil polyester liner to reduce liner waste by 50% and save the time and cost of second liner removal and disposal. Stable liner release with low gms/in over time and a 12-month shelf life extend usability for a better return on your tape investment.
Make a winning combination with the 3M TSR Program
Barnes and Noble. Bow and arrow. Holmes and Watson. All the right combinations. Same as your tough bonding challenge and the 3M TSR.
Using the 3M Technical Service Request (TSR) Program, a 3M representative will work with you on initial testing of an adhesive design solution. One or two best options will be identified then a sample of your substrate is brought to the 3M Laboratories and tested for stress or other factors the product will encounter. The 3M test results will help you select the best design solution for your manufacturing process and customer needs.
Work with 3M at your manufacturing plant through the 3M IATD Design Solutions Program
Using the 3M IATD Design Solutions Program, we identify a design solution then works side-by-side with you, at your manufacturing plant, to ensure your personnel are trained in the new manufacturing process. Follow-up visits and ongoing support are key parts of the program.
We are eager to work with you. Please contact us by email to discuss your project or call: 1-800-362-3550.