“Can you recommend the most appropriate UV-curable adhesive to bond ABS connectors to polyurethane tubing in a medical device application? It is a polyether aromatic polyurethane tube to a transparent ABS connector.”
For this type of application I suggest trying DYMAX 1161-M. This adhesive cures with UV and visible light and exhibits good adhesion to ABS and PUR. It also fluoresces blue for quality purposes. If you are interested in See-Cure patented color-change technology, I would recommend DYMAX See-Cure 1201-M-SC. This product is blue and helps verify that enough adhesive has been dispensed. Upon exposure to UV/visible light, the adhesive turns clear to confirm complete cure.
“I need to bond a plastic cap to an alloy/some type of metal shaft. The application is really similar to the two bottom joysticks of a playstation controller where you have the plastic cap that bonds on the resistive joysticks made of an alloy/some type of metal shaft. Any ideas about what adhesive might work best?”
Without knowing what the plastic is, the size and what type of environment this will be exposed to, it is difficult to make an accurate recommendation. However, based on what you provided we would recommend looking at a cyanoacrylate (instant adhesive).
“I am interested in a low-viscosity epoxy (<100 cp) with good adhesion to ceramics and stainless steel. The objective is to seal a small metal sensor inside a ceramic casing at room temperature. There is no contact with the patient. What type of epoxy do you recommend?"
Based on the substrates, ceramic and stainless steel, and the room-temperature requirements, I would recommend looking at a cyanoacrylate (instant adhesive) or a two-part epoxy.
Cyanoacrylates are available in very low viscosities. You may want to evaluate the DYMAX 222 Series which offers cyanoacrylates in a variety of viscosities. Low-viscosity epoxies are rare. One option could be two-part epoxy 301 from EPO-TEK, which is 100-200 cP.
“I understand DYMAX has a masking material that is biocompatible or had biocompatible testing done on it?”
DYMAX provides a selection of adhesives (http://www.dymax.com/products/medical/index.php) that have been tested according to ISO 10993 and are biocompatible in the cured stage.
A medical-grade material is typically not needed for temporary masking applications where the light-curable resin acts as a manufacturing aid only and is being removed before the end product is finalized.
“I am trying to bond 304 stainless steel to 304 stainless steel without welding. A strip of stainless steel is put into place once the device is completely assembled and welding would damage sensitive electronic components. The strip of stainless steel is currently held in place with high bond-strength double-sided tape with foam between the adhesive layers. The foam helps the strip to take its shape over slight surface variations in the welded cabinet it is being affixed to. The problem is that the foam can be shifted over allowing access to what is behind the strip. Pry bars have then been used to gain access into the device. It has been difficult to find an adhesive that can allow for surface irregularities. The adhesive must be able to withstand outdoor temperature extremes, moisture, and UV since this device can be permanently installed anywhere. The adhesive must also have other special properties because the strip is installed vertically to the cabinet and it is done on a shop floor where there are a lot of people around. Any ideas?”
For such extreme environment requirements and gap configuration, a 2-part epoxy could possibly be the best solutions for this application.
“We want to bond Polyurethane to PU, Polyurethane to latex, and PU to polycarbonate. A little flexibility would be helpful. Visibility of the bond would also be desirable. Do you have a product that meets these requirements?”
DYMAX offers 204-CTH-F light-curable adhesive, which is recommended for single-use medical devices made of Polyurethane, PVC, Polycarbonate, and many other plastics. This adhesive fluoresces blue under black light for quality purposes and is suitable for assembling rigid and flexible components due to its flexibility.
Since latex is very difficult to adhere to, 204-CTH-F may not provide the desired bond strength. Typically, a cyanoacrylate like DYMAX 222 Series is used for latex; however, it will not provide a flexible bond.
If you want to be able to see the adhesive while you dispense it and get confirmation of cure, I would suggest trying DYMAX 1201-M-SC or 211-CTH-SC. Both are light-curable adhesives equipped with DYMAX patented See-Cure color change technology. Adhesives formulated with See-Cure technology are visible when dispensed onto substrates due to their bright blue color while in the uncured stage. When fully cured, they become colorless to visually assure they have been cured.
“We need to glue an epoxy-coated magnet to a copper-clad FR4 PC board. The UV-cure glue needs to resist mechanical shock without cracking. Any Ideas?”
DYMAX offers 6-625-SV01-Rev-A, a flexible light-curable adhesive with secondary heat cure and activator cure capabilities for shadowed areas. Its high viscosity of 10,000 cps also enables it to be dispensed from the outside and act as an edge-bonding material.
“We offer a permanent surface treatment that increases the dyne level of plastics. We have heard that each adhesive system works best with a certain dyne level, and you can actually have too high a dyne in some cases. Can you clarify?”
Typically, the dyne level of the substrate must be higher than the adhesive for better wettability. Our adhesive chemistry (polyurethane modified acrylates) are about 30-47 dynes. We haven’t come across any issues where the dyne level of the substrate was too high.
“What is the best type of adhesive to use to join two threaded components that are reusable and generally sterilized by steam chambers at temperatures up to 275°F?”
For devices that require repeated cycles of steam sterilization, I would suggest a two-part or heat-curable epoxy. Masterbond and Epoxy Technology offer such products in medical grade versions.