When it comes to bonding rubber or rubber-like materials, selecting the right adhesive can be a challenging task, especially when the exact type of rubber is unknown. Rubber bonding is crucial in various industries, such as automotive, manufacturing, and even marine applications. In this article, we will explore different types of rubber, the best adhesive options to bond rubber, and frequently asked questions about using adhesives like Permabond POP for rubber bonding.
Types of Rubber
Identifying the specific type of rubber you’re working with is essential before choosing an adhesive. Some common types of rubber include:
- Nitrile Rubber (NBR): Commonly used in applications like hoses, O-rings, seals, conveyor belts, and cable and printing rollers.
- Butyl Rubber (IIR): Known for its flexibility and used in applications like inner tubes, seals, and valve seats.
- Polyurethane Rubber (PUR/TPU): Used in high-performance molded applications.
- Natural Rubber (NR): Often used for carpet mountings and support elements.
- Silicone Rubber (VMQ): Resistant to high temperatures, making it suitable for O-rings, seals, kitchen utensils, medical devices, and prosthetics.
- EPDM Rubber: Suitable for hoses, seals, and more.
These are just a few examples, as there are many other rubber types, including SBR, latex, neoprene, and more.
How to Bond Rubber
Before attempting to bond rubber, it’s important to prepare the surfaces properly:
- Clean the Surfaces: Use a solvent or industrial cleaner to remove any surface contaminants like release agents, anti-friction additives, or lubricants. Isopropanol is a good option for quick cleaning, but be cautious with acetone as it can harm some types of rubber.
- Adhesive Selection: While epoxy adhesives are generally not recommended for rubber bonding, cyanoacrylate instant adhesives are often the best choice. They cure quickly, allowing you to check the bond’s strength almost immediately.
- Application: Apply a small amount of cyanoacrylate adhesive to the surfaces to be bonded, ensuring they are firmly pressed together. If the bond fails after proper curing time, it may indicate a tougher rubber type, such as EPDM or silicone rubber.
Bonding Silicone Rubber with Permabond POP
Silicone rubber can be challenging to bond, but with the right approach, it’s achievable. Here’s how to bond silicone rubber using Permabond POP:
- Cleaning: Clean the surfaces with isopropanol to remove any removable agents.
- Apply Permabond POP: Apply Permabond POP as a primer and allow it to dry.
- Apply Cyanoacrylate: Use Permabond cyanoacrylate adhesive like Permabond 105 for most applications or Permabond 2050 for more flexibility.
Frequently Asked Questions about Permabond POP
What is Permabond POP?
Permabond POP is a primer, or adhesion promoter. It is not an accelerator, so it’s not suitable for increasing curing rates or changing the pH of acidic surfaces like wood.
Is There a Time Limit for Bonding Parts Treated with POP?
Some general guidelines apply:
- For many substrates, bonding with Permabond cyanoacrylate adhesives can be done up to 2 hours after applying POP.
- When bonding PTFE, it’s recommended to bond the parts immediately after applying and drying POP.
- In all cases, it’s best to achieve the bonding as soon as possible for optimal results.
What Does Permabond POP Do?
This polyolefin primer significantly enhances the bond strength of cyanoacrylate bonds on polyolefins (such as polypropylene and polyethylene), acetal (POM), and silicone. It also works on fluoropolymers (like PTFE, FEP, PFA, ETFE). It often improves bond strength on PBT, PMP, PPS, polystyrene, and polyurethane grades.
Substrates That Don’t Work Well with Permabond POP
- DAP and polyamide: Bond strength decreases when using POP.
- ABS: POP does not provide a noticeable increase in bond strength.
Will It Improve Epoxy Adhesion?
Permabond POP is only recommended for use with cyanoacrylates. It will not enhance the adhesion strength of other adhesive types, such as epoxies, UV adhesives, or acrylic adhesives.
Conclusion
Bonding rubber, especially when the type is unknown, can be a daunting task. However, by understanding the various types of rubber, proper surface preparation, and selecting the right adhesive like cyanoacrylates or using primers like Permabond POP when working with challenging materials like silicone, you can achieve strong and reliable bonds. If you have specific questions or need personalized recommendations for your application, don’t hesitate to reach out to us. We are here to help you optimize your production processes and address any adhesive-related challenges you may encounter.