Alternatives to Plexus® adhesives; what is the best solution for you?

If you find yourself wondering if there are alternatives to Plexus® adhesives, look no further. Yes, there are alternatives, but it all depends on what you’re looking for.

As a manufacturer of specialist adhesives here at Forgeway, engineers in the manufacturing industry often ask us this question.

It’s critical for us to address this topic because when manufacturers like yourselves are seeking information on alternatives, it’s often because you are facing a problem with the product and want to change. Supply chain issues can also create the need to look at other options 

We have helped a multitude of manufacturers overcome their issues with Plexus®. We will be discussing your alternative options, some of which are our products. However, the purpose of this article is to educate you, not to promote our products. 

In this article, we will walk through some common problems with Plexus® adhesive (although this is likely due to the type of glue, not Plexus® itself). After that, you will see our top five alternative options.

By the end of the article, you will be able to determine the actual cause of why you are looking to change. It could be an issue with the supplier but it could very likely be the adhesive product. Read on to find out which it could be.

But first of all, we should give a bit more background to Plexus®.

What is Plexus® Adhesive?

Illinois Tool Works (ITW) is the company that owns the Plexus® product line. Plexus® is ITW’s Methyl Methacrylate adhesive (MMA) product.

To complicate things, Plexus® has become the generic trademark for Methyl Methacrylate Adhesives. In simpler terms, it just means most people call MMA’s Plexus®. Much like how the general public would call cola-flavoured soda ‘coke’. Or how most people call vacuum cleaners ‘hoovers’.

So when someone is talking about Plexus® adhesive, they likely mean MMA. (Whether or not they are actually using Plexus’® product).

Now that we have defined what Plexus® likely means, we will go into a bit more detail about Methyl Methacrylate adhesive.

Methyl Methacrylate adhesives are a two-component structural adhesive that are growing in popularity (more on that later). There are two main ratios of MMAs, 1:1 and 10:1. The difference? 10:1 uses 10 times more of one component, whereas 1:1 uses equal amounts.

Two-part adhesive
10:1 Methyl Methacrylate-based adhesive

1:1 would likely cost around £30 per 400ml cartridge whereas 10:1 would likely cost more than £50 per 490ml cartridge. The reason some people prefer 10:1 is because it is much more flexible than the 1:1 alternative. 

These prices are averages. Some situations can affect the price to be more or less.

Why are Plexus® and Methyl Methacrylate Adhesives popular?

As mentioned earlier, MMAs have been rising in popularity recently. There are good reasons too. But first, let’s go over the other types of adhesives and then discuss what sets MMAs apart.

There are three main types of structural adhesives. Epoxy adhesives, polyurethane adhesives, and methyl methacrylate adhesives. Of those three types, MMA is the only option that is truly primerless.

The reason it is primerless is because it isn’t affected by surface contaminants. It ‘cuts’ right through any contaminants. Therefore, it will not need to have optimised surface preparation.

On the other hand, Epoxies and polyurethanes will require optimised surface preparation. So to begin with, it is a lot more simple to apply.

Surface activator being applied

You are probably thinking, surely that’s not all? You would be correct.

MMA offers exceptional durability and performance and can be widely used on various surfaces. Plastics, metals and weld replacements are some examples of where MMAs can be used.

Whilst epoxies are known to be very strong, they are also extremely brittle. 

The opposite is true of polyurethanes. They are very flexible but not especially strong.

MMA is the best of both worlds. Granted it doesn’t excel at either, but MMA’s offer good flexibility (not quite as flexible as polyurethanes) while remaining nearly as strong as epoxy adhesives.

It is perhaps worth mentioning that the cure times of epoxies are very sensitive to changes in ambient temperature. As our other article explains in more detail, ambient temperature is the biggest factor in affecting the cure time of adhesives.

MMAs are much less sensitive to changes in ambient temperature. This means the cure speed is a lot more consistent and reliable, regardless of ambient temperature.

Why Methyl Methacrylate Adhesives may not be a good fit

If you haven’t used a Methyl Methacrylate adhesive before, beware. It stinks! This is technically known as ‘having a very distinct odour, making it difficult to work with’, cutting straight to the chase, it doesn’t smell pleasant.

However, this smell can lead to confusion. Some consider the smell to be toxic and dangerous, but it isn’t.

This may not be an issue for you. Some people make out the smell is worse than it actually is. There are even occasions where it is barely even noticeable. We would say that the smell only becomes an issue if you are working in confined spaces or a room with limited airflow. 

It is something to be wary of though.

The other significant point to remember about MMA’s is the fact they exotherm as they cure. 

Exothermic curing can lead to witnessing or read-through on the substrate. Because it gets so hot during the curing process, it leaves a mark on the substrate.

burn mark on a plastic from exothermic reaction
The left shows a burn mark on a plastic with a low melting point. The right shows a plastic that doesn’t have a low melting point.

In extreme cases, it can even melt the substrate although this is usually only on plastics or materials with a low melting point.

It’s hardly an issue, it’s more something to be aware of. Some manufacturers have even developed MMA products that overcome this issue. Some examples are the Plexus® MA8 120 and our very own Forgeway VX61.

As previously stated, the purpose of this article isn’t to promote our product. We just want you to know about the available options should you wish to explore this point any further.

Our top five alternatives to Plexus® adhesive

Now that you have got to this part, you should hopefully have more of an understanding of Plexus® adhesive. As described, Plexus® adhesive is the household name for Methyl Methacrylate adhesives.

In the following section, we will be exploring five alternatives to the Plexus® adhesive brand. 

For the sake of the list below, we’re not including our own products. We’ll be listing some of the other top choices you should consider. The following are the brands we frequently come across that also supply MMAs. This list is in no particular order.

  1. Parker Lord corporation is a US manufacturer of MMAs.
  2. Bostik’s (Arkema) SAF range is one of the largest manufacturers globally of Methyl Methacrylate adhesives.
  3. Scotchweld is the brand of 3M’s structural adhesives. They have a range of MMAs.
  4. IPS owned Scigrip have manufacturing facilities in the US and UK. Their main product range is MMAs.
  5. Crestabond is the brand for Methyl Methacrylate adhesives owned by Scott Bader in the UK.

There are several other manufacturers we haven’t included on this list. In fact, there are more than 10 manufacturers globally who also supply this product. These are the most common though. 

When considering Plexus® alternatives, do you need a different supplier or a different product?

At this point, you will be able to determine other adhesive manufacturers who also supply MMAs. However, the original problem may not be down to the supplier, but with the type of adhesive itself.

If you think a different adhesive solution sounds like a better fit, the list above will give a good indication of other adhesive manufacturers who could supply you. 

We already touched on a few of the other potential products that could be a good fit. But as a recap, epoxy-based or polyurethane-based are the two main alternatives to MMAs.

But, if you want to read more, we advise you to download our Ebook ‘The Fundamentals of Adhesives’. Chapters four, 14 and 15 are likely to be of significant interest based on this article. However, the whole book will be of interest and covers a range of products.

Here at Forgeway, we manufacture a wide range of adhesive solutions. We understand you may not know what you should do next.

If you think a different supplier may solve the problem, the list above will give you a good idea of who may be able to help. Alternatively, you can get in touch with us and one of our staff will be in touch to help.