“We need to bond a Mylar film with a PET backing to extruded ABS sheeting. We are looking for a liquid and/or PSA. The criteria we need to achieve:
• Adhesion for a period exceeding five years
• The finished product will be in high-humidity environments and exposed to fresh/salt water spray
• Temperature variation -20 to 180ºF (or very close)”
A silicone sealant/adhesive (Pt curable) or silicone pressure-sensitive/lamination adhesive would all be good options to evaluate. A PSA like Dow Corning Q2-7406 (solvent based, peroxide cure) would be applied to the Mylar film by draw down bar/myer rod, drive off the solvent at 65oC for two minutes, cure at 150°C for two minutes, and then apply to the ABS. You could also devolatilize the solvent, apply the film and uncured PSA to the ABS, and then cure at 150°C in more of a lamination-type application. If a lower temperature is required, then Platinum-curable DC 7657 & Syl-Off 4000 catalyst could be mixed and then cured between 80-130°C (after driving off the solvent). For a solvent-free option, DC 2013/Syl-Off 4000 would be a good option.
"Our research lab is looking for a medical-grade adhesive to bond:
1.) Dacron cloth to silver plate and
2.) Glass and PMMA optical cylinder in a silver tube.
It needs to be moisture resistant and should last for a long time (20 years).
Please suggest a product."
Dacron is a commercial name for PET, or polyethylene terephthalate. Bonding cloth to a rigid substrate like a silver plate can be done in a few different ways. Bonding to cloth is mostly a mechanical lock that forms by encapsulating strands of the cloth and then locking them to the rigid substrate. The viscosity of the adhesive will play a role, as the thinner the viscosity, the more it will wick into the cloth. A very high viscosity will not wick very far into a cloth. A 2-part epoxy, such as found from Loctite or 3M, or a 2-part urethane, such as found from Lord Corporation, are just two products that you might want to explore. A silicone adhesive may also do the trick, and would suggest contacting representatives of Dow Corning, Momentive Performance Materials, NuSil Technology, or any of the other silicone manufacturers.
To bond glass and PMMA you may be able to use the same adhesive, but the application might require a lower-viscosity material, depending on the gap between the parts and method of assembly. The epoxy and silicone systems will be moisture resistant and have good usage life, but most manufacturers will not warrantee a 20-year usage lifetime. A 1-part, light-curable urethane acrylate, like 203A-CTH or 209-CTH from DYMAX, are options if you can get light to the adhesive.
Adhesives, Catheter Bonding, Medical
“I am looking for an adhesive that can be used to bond an injection-molded PET part to a stretch blow-molded PET container. Ideally, this adhesive should be compatible with the PET recycling stream. Any recommendations?”
There are a few options available to bond PET to PET, whether injection molded or stretch-blow molded. One available option is light-curable adhesives. These adhesives are available from Partner Pak, and a few other players in the market that work closely with the container/packaging industry. While DYMAX has not tested each material for the recycle-ability of our adhesives, David Cornell, the Technical Director from APR (Association of Postconsumer Plastic Recyclers, www.plasticsrecycling.org) offered these comments regarding PET clamshells
Does the presence of the adhesive:
- Cause the PET to yellow when re-melted?
- Cause the IV of the PET to fall excessively when melted?
- Cause haze in melted PET?
- Cause films to crystallize too quickly?
- Cause black specks in melted PET?
Generally, one should find out by testing a control of un-bonded components and a test sample of bonded components. Make new components by grinding up bonded and un-bonded structures separately and processing as regrind after the hot water wash. If you find no difference in appearance and performance at 25% and 50% regrind levels, the adhesive is probably not going to be an issue if the clamshells are recycled.
Clamshells generally are not pursued as sources of recycled PET, but PET clamshells do occasionally end up in bales, asked for or not. As such, the real world experience would have the adhesive present at much less than 25% of the recyclate. But if you can show no problems at 25%, concerns will be allayed. The cured adhesive should not affect solid stating performance, but should be tested fully.
My thought is that there is no problem with recycling PET sealed with a DYMAX light-curable adhesive since our adhesive is a clear thermoset (when cured) that constitutes a small % of the total assembled package.
“I’m looking for a UV adhesive that will bond a PET or Acrylic lens to a photo print such as those you get from a professional photo lab.”
DYMAX light-curable dome coatings have crystal-clear coating/adhesive properties, and stick well to plastic lens, thin films, and professional photo printing paper, without wrinkling or distorting the image. I recommend a soft, flexible A-70 durometer material with a viscosity of 1,500 cP that it is easy to apply and roll onto the printing paper surface, so the entrapment of bubbles is eliminated. It’s important to use a low-medium intensity light to reduce stress during cure. Other coatings are available that provide a glossy, scratch-resistant coating over the photograph, usually in applications without a covering of PET or acrylic lens.
A recent question came in about a recommended plastic-bonding adhesive:
“We’re looking for the best clear adhesive that will work with polyethylene terephthalate (PET) material. The adhesives we have tried in the past often react with PET and turn a translucent white color. Can you recommend an adhesive that will not have this reaction with PET and remain clear upon application?”
A large number of clear adhesives work with PET material. The material you select will depend on whether the part in question is a molded PET part or a thin film. It will also depend on whether you are looking for a medical, industrial, or packaging-grade adhesive. There is even an adhesive for use with PET material that changes color when it is cured, indicating that it has received enough ultraviolet light. Choosing the proper light source is also important and will depend on whether the application requires the curing of a 3-D part or whether it involves a web coating or lamination. All of these materials are designed to provide a crystal-clear bond line without stressing the PET material, which causes the translucent white effect you refer to.