“We are looking for a medical-grade adhesive for bonding PEBAX (72D MED) tubing to latex nature rubber. We need shore hardness of a UV adhesive below 50D after cured. What is the best adhesive for this application? Also, which pre-surface treatment is suitable for PEBAX?
We also need a medical-grade adhesive for bonding PEBAX (72D MED) tubing to a colored ABS hub. Which fast setting adhesive is suitable for this?”
Latex nature rubber can typically be bonded with cyanoacrylates, also referred to as Super Glue. The Dymax medical grade 222 series cyanoacrylates might be a good place to start.
For bonding PEBAX I would suggest looking at Dymax 208-CTH-F, which is a medical grade, light-curable adhesive with shore D55. To combine PEBAX with latex or colored ABS, light-curable adhesives might not be suitable due to low adhesion to latex and problems with light curing through the colored ABS hub. Therefore, a cyanoacrylate is most likely the adhesive of choice.
Adhesives, Cyanoacrylates, Medical
“I am trying to adhere a Polyethylene (PE) foam material onto a Polyethylene (PE) rigid, smooth plastic material. I prep both surfaces with a primer (Loctite 7701) before dispensing the adhesive, which is Loctite’s 4011 cyanoacrylate medical-grade adhesive. The adhesive is anchoring or sticking really well to the PE foam, but not the rigid plastic. They are both PE materials and I am not sure why it would adhere to one and not the other.
Are there different primers that vary in performance?”
One reason why the adhesive might stick better to the foamed Polyethylene (PE) is its larger surface. Due to the holes and grooves, adhesives in general can hold on better and achieve a mechanical lock.
According to the suppliers web site, the primer you are using is recommended for PE. If it is not providing the desired results, you may want to look into another surface treatment method such as plasma or corona, which adds polar groups to the surface and usually results in higher bond strengths.
“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.
“Which type of cyanoacrylate can be used for bonding skin/tissue together instead of suturing small wounds or incisions? Does DYMAX supply such a material? “
There are four types of cyanoacrylates. Two of them can be used for closing wounds and are available from different suppliers:
- Butyl cyanoacrylate is used to bond skin and close wounds and is available from Henkel (Indermil), Advanced Medical Solutions Group (LiquiBand), and B. Braun (Histoacryl). All versions are FDA approved.
- Octyl cyanoacrylate is a newer-generation cyanoacrylate for bonding skin and closing wounds. It is supposed to provide higher breaking strength and be less irritating to skin than the butyl-type adhesive. This type of cyanoacrylate is available from Adhezion Biomedical (SurgiSeal), Ethicon (Dermabond), and Chemence Medical Products (derma+flex QS). All products are FDA approved.
- Ethyl cyanoacrylate is the most commonly used adhesive for assembly purposes and the type of cyanoacrylate supplied by DYMAX.
- Methyl cyanoacrylate is used for assembly purposes.
“What type of adhesive would I use to bond latex and latex-free rubber to brass?”
Latex rubber can usually be bonded with cyanoacrylate, commonly referred to as super glue. In most cases cyanoacrylates have excellent adhesion to brass. Latex-free rubber can include any number of types of rubber, from synthetic rubber, butyl rubbers, and isoprene, to even silicone, so I can not make a recommendation right now. However, cyanoacrylates would be a good starting place. Cyanoacrylates come in different viscosities such as low water-like viscosities of 20 or 50 cP, higher viscosity materials like 500 cP or 1,000 cP, and all the way up to GEL viscosities. Cyanoacrylates also come in different grades like low odor, low bloom, surface insensitive, and rubber toughened for better impact resistance. DYMAX 222/100, which is a low odor/low bloom cyanoacrylate, might be a good place to start, and then you can refine the adhesive selection from there.
"I have an application bonding opaque parts with a Cyanoacrylate (Super Glue Type). There is much surface area and I have a very good bond. Will Gamma Sterilization effect my bond strength?"
Most cyanoacrylates will survive 1x, 2x, and sometimes even 3x gamma sterilization without a significant impact on bond strength. Repeated Gamma sterilization will start to add additional crosslinking, which will start to reduce elongation. As most cyanoacrylates are already brittle materials (depending on the grade), the adhesive may become even more brittle. Drop tests, impact testing, or tensile testing may be a good indicator of the final impact on your bond strength.
Adhesives, Cyanoacrylates, Medical