Tips for Gluing Plastic Plain Bearings

Plain bearings are usually pressed (pictured right) or clamped into mounting holes so that they are held securely in the bore and do not turn unintentionally. However, bearings will move out of the housing if the press fit is lost and there is no additional axial securing. Although it is not always the cheapest or fastest method for axially fixing the bearing, there is the option of using an industrial glue. But there are probably as many adhesives as there are bearing materials. Which is the right one? And what should you watch out for when gluing plastics? Here are a few tips. 

Gluing Plastic Plain Bearings With the Right Adhesive

There are many adhesives for bonding plastics. The problem: Plain bearings are often not made of "simple" plastics, but of plastic compounds or blends. These are mixtures of plastic polymers and additives and fillers that complement their properties. Substances that improve the sliding properties, such as silicone, MOS2 or PTFE, can be problematic here. In these cases you should seek advice directly from the manufacturer of the plain bearings.

Here at igus®, we used two-component adhesives in particular, a combination of Loctite 406 and Loctite 770 primer. Loctite 401 without a primer also produces good results for plain bearings made of plastics with lower proportions of substances that improve the sliding properties. Of course, comparable adhesives from other manufacturers can also deliver potentially good results.

Important: Prepare the Surfaces to Be Bonded Well

As in many situations in life, the following applies when gluing plastic plain bearings: Preparation is everything. So that everything holds up well in the end, you should consider the following things:

• Remove dirt, rust and other foreign matter from the surfaces to be bonded
• Roughen the surfaces a little by sanding them
• Thoroughly degrease the adhesive surfaces, e.g. with alcohol, nitro thinner or acetone
• Let the glued areas dry well

We Are Happy to Help!

Gluing in plain bearings is often not the ideal form of plain bearing assembly. Especially with medium quantities, the additional installation effort represents a not-inconsiderable cost item. Often, even small changes to the component tolerances or component geometry can make gluing superfluous.

But even if there is no way around gluing, we not only advise you on possible alternatives to gluing, but also, if necessary, on the best design and execution of glued joints for plain bearings.

Read this tech talk to learn more about how to properly secure bearings, or reach out to our iglide® Product Manager with any questions.