“I’m looking for a UV-fixating adhesive to bond a steel cannula onto a polypropylene hub. The hub will be plasma or corona treated prior to gluing to increase the bonding performance and the hub will have annular rings as well. However, since the material is opaque I assume the adhesive has to have a secondary curing mechanism too? In addition to the above, the fixation time for bonding needs to be <10 seconds. Can you please advise which of your adhesives might be suitable?"
On occasion full cure via UV/Visible light can be achieved with opaque PP hubs.
Depending on the color and thickness of the polypropylene, some light from the side can transmit through the plastic and polymerize the UV/VIS adhesive. The largest area of the adhesive is usually cured from the top. However, due to limitations in depth of cure of most UV/VIS adhesives, I would recommend keeping the length/depth of the bond joint to a minimum and mold the annular rings near the top of the hub. Suitable UV/Visible light-curable products are DYMAX 1180-M-SV04 and 1-20777, which are medium viscosity and won’t flow deep inside the hub. Low-viscosity products such as DYMAX 1161-M or 1162-M can be used if the design of the bond joint prevents these materials from flowing too deep inside the hub.
In order to achieve short curing times I would recommend high-intensity UV lamps such as Fusion F300, which is a focused beam lamp or DYMAX BlueWave® 200, which is a spot-lamp that can be equipped with multi-wand lightguides.
Adhesives, Curing Equipment
“We are currently using your DYMAX 1-20323-W UV-curable epoxy on a piece of PVC Tubing. Is there a way to dissolve this epoxy without damaging the PVC? We want to remove this epoxy for re-work reasons.”
Fully cured UV-adhesives such as 1-20323-W are cross-linked, thermoset resins, which do not melt and may be difficult to remove from a substrate, especially if they stick very well to it.
For your removal purposes, I would recommend heat or chemical exposure to weaken and then remove adhesive bonds or coatings. It may be very difficult since PVC and the cured adhesive have similar limitations in terms of temperature and chemical resistance.
I suggest placing a part in an oven at 60°C (140°F) for 10 minutes and immediately apply a peel or cleavage force to the bond or coating. Next you can try to increase the temperature up to where the part will not be adversely affected.
There are several chemicals that will dissolve or swell 1-20323-W, such as Dichloromethane, MEK, and Acetone; however, these will also damage the PVC and may not be suitable for your specific needs. Using isopropyl alcohol (IPA) may be the only option in this particular case. A long soak in warm IPA with the help of an ultra sonic cleaner could be the last option if previously mentioned options did not provide desired results.
“Please help me source an adhesive that will break down when put in contact with boiling water. The preferred mode of breakdown would be for the adhesive to desolve upon exposure to boiling water for a short time.”
The right choice depends on what needs to be accomplished with the initial bond. To adhere two substrates together and later be able to take them apart easily, you can try Master Bond MB600, a single-component adhesive for glass, metal, and many plastics, that cures at room temperature as well as via exposure to heat. For temporary coating or masking of a surface, I suggest looking at DYMAX 713-Gel, which is a light-curable temporary masking material. Both products dissolve easily in hot water.