Ultimate Guide to Static Mixers for 2-Part Adhesives

Two part adhesives like Epoxies, MMA’s, Urethanes and Silicones require plastic static mixer nozzles to mix and dispense the A and B sides. The two materials enter the static mixer where they run through a series of chambers called Elements which mix the two sides and activate the curing process. Static mixer nozzles are an excellent way to save time and money over trying to mix and dispense two part adhesives by hand.

Because there are so many different adhesive ratios and cartridge types, choosing the correct static mixer can get a bit confusing. In this video, we’re going to explain all of the cartridge and nozzle options so you can be confident when choosing a static mixer for your dispensing needs.

If you're more of a visual learner, we've put together an extensive video reviewing all of the current static mixer types, sizes and technologies.

Static mixers can take any number of forms, each suited to particular applications and with unique advantages and disadvantages. These include in-line mixers, where components are placed as a permanent part of the dispensing line, and static dynamic mixers, which have moving parts but are not powered. Disposable bayonet mixers, however, are by far the most common and widely applicable. Disposable static mixers take the form of a nozzle that attaches to either meter mix and dispense (MMD) or handheld dispensing equipment. Their internal components can vary greatly depending on the needs of the application. The most common are the helical type and the box chamber type. Disposable static mixers are designed to be thrown away after use which can be cost effective compared to the flushing and cleaning necessary in non-disposable mixers. They also make sense for equipment which will handle multiple adhesive types.

Before we dig into the different sizes and connections on static mixer nozzles, we're going to briefly discuss the difference between standard and Quadro (also known as Turbo) mixers.

Standard static mixers are the oldest technology in two part adhesive dispensing. These nozzles are round and come in a wide range of connection types. Standard mixers typically require longer nozzles and more mixing elements to create the same mixing quality as Quadro mixers.

Quadro mixers are the newest technology to two part cartridge dispensing and are square in shape. Quadro mixers allow for more complete mixing in a shorter nozzle. The advantage of Quadro style nozzles is that there is less wasted adhesive left over in the nozzle and users can get closer to their substrates when dispensing.

The type of static mixer nozzle you will need will depend on a number of different factors but users should always start with the type of connection required. Different cartridges and dispensing equipment use different connectors. After you are confident the connection type is correct for your equipment or cartridge, then the best static mixer can be chosen for a particular adhesive or application need.

• Dispensing Equipment - One key consideration is if the adhesive will be dispensed by machine or hand held application. Disposable mixers are more frequently used for handheld equipment and are compatible with various cartridge sizes. Machine dispensing applications may also use static mixers, particularly when adhesives are being changed or other mixing options aren't feasible.
• Shot Size - A larger shot size/faster dispensing will require fewer mixing elements and a larger diameter opening. Because a larger diameter usually means less-efficient mixing, a balance is required between the two. Smaller shot sizes require more mixing elements and smaller diameter for an ideal mix.
• Adhesive Characteristics - Thicker adhesive components require larger diameter openings to flow and mix properly. The difference between component viscosities will also affect the number and type of elements needed.

The first step to choosing the right static mixer nozzle is knowing what size cartridge or meter mix equipment you will be dispensing from. We're going to review all of the available mixer nozzle options cartridges from 50ml all the way up to high volume meter mix equipment.

50ml cartridges for two part adhesives are extremely popular and a great way to mix and dispensing two part adhesives for low volume applications or those that require lightweight, precise application of material. There are two types of 50ml cartridges, each of which require a different type of mixer nozzle.

Larger cartridges for two part adhesives are a great option for medium to high volume dispensing application. There are two types of larger cartridges, each of which require a different type of mixer nozzle.

Meter Mix equipment is perfect for high volume applications and needs. Bell static mixing nozzles are a high quality, low cost solution for a wide variety of high volume applications.

Static mixing nozzles for rotary machine dispensing equipment are designed for use with specialty meter mix and dispensing equipment. Static mixing nozzles provide inexpensive solutions for the dynamic mixing, with elements that rotate within the nozzle attachment.

The materials you are mixing directly determine the range of elements needed to mix the materials into a homogenous material. Some materials are considerably more difficult to mix than others, so it is crucial that you have the appropriate amount of elements in your mixer to get the mix you need.

Some common materials you will likely be working with include acrylic, epoxy, poly-sulfide, PU foam, silicone, and urethane. Typically, the element range needed for each of these separate materials is as follows:

There are two factors that can indicate you should use a number toward the higher range. The first is the viscosity of the materials; if the two elements have very different viscosities (i.e. material A is 5,000 cps and material B is 150,000 cps), you will likely need to use the higher number of elements. The second is the material ratio; if you are dealing with a mixing ratio of 7:1, for example, a higher number of elements will be needed to achieve a pure, homogenous mix.

This question will help you determine what connection style/inlet you will use with your mixer. There are three main connection types: bayonet, bell, and integral nut (threaded). Bayonet mixers feature a simple twist-and-lock system, and are recommended for 9-50ml cartridges. Bell mixers come in a slightly larger variety, with options for round, square, and rotary connections. Typically bell mixers are used for 200ml cartridges, or larger. Inline, or threaded mixers, are also for larger cartridge sizes, but do not require the use of a retaining nut.

Choosing the best static mixer for your application is a process but looking at your type of cartridge or valve, what material you're working with, your mixed viscosity of both fluids, and what dispensing application you're aiming for what will help with the process. As always, these are guidelines and it's important to consult your local sales rep for proper testing. Also be sure to check out our Static Mixer Tool to find the perfect mixer for your application.