Pasty adhesives and sealants are available in cartridges (standard size: about 300/310 ml), but also in so-called economy packs (often called "foil cartridge," "foil bag," or simply "bag"), packed with 300–600 ml of content. Consequently, there are cartridge presses available in at least two sizes or lengths, namely for cartridges and for foil bags.
Since commercially available adhesives and sealants cover a wide range of viscosities, cartridge guns powered by hand, compressed air, and batteries are manufactured with different pressure ratios.
For some applications (e.g., in the encapsulation of components), low-viscosity, even almost liquid, or at least thick products are used. For others, on the other hand, very high-viscosity products (e.g., in the elastic bonding of different materials using the stress-equalizing thick-layer process; The most prominent example is certainly the windshield bonding in cars).
If we look at manual cartridge presses as an example, the possible and actually covered by Innotech pressure force translation ranges from 7:1 to 35:1, with the achievable advances being 12.5 to 2.8 mm. However, the maximum pressure force of 1.0 kN to 5.0 kN is only achieved at the pressure tip.
This aspect alone makes it clear that there cannot be a "standard" or "universal" press.
To choose the "right" cartridge press, in addition to the material characteristics (e.g., viscosity, but not only that), the specifics of the respective application must also be considered (e.g., the amount to be dispensed for the respective application). This way, you can find THE right cartridge press for the selected material and the intended application.
Even with the pneumatic presses, there are different designs, also adapted to the material to be applied and the task to be performed. Selection criteria are as follows:
1. The precision of pressure regulation
At Innotech, there are three different pressure regulators that allow for optimal fine adjustment with half to four turns. The precision of the setting with maximum repeatability is particularly important whenever small quantities need to be dosed accurately.
2. The maximum pressure force with the pressure regulator fully opened
Almost all adhesive manufacturers have materials ranging from low to high viscosity, so there can't be THE one cartridge press that is equally suitable for everything. Innotech offers over 15 different performance options, and each device can be retrofitted to adjust its performance to a new material or application if needed.
3. The repeatability or reproducibility
Here, the question is: "Is every application the same?" The processor values this for technical reasons as well as for optical ones... after all, the adhesive application should be in a reliable quantity and the sealant application should have impeccable optics.
That's not all: Different controllers and maximum pressure can be combined, leading to hundreds of new possible variants from which can be selected according to individual customer needs. In this context, the material to be processed and the desired output quantity per given time unit are considered the most important selection criteria.
When working in an industrial environment with a compressed air cartridge press, one usually uses the in-house compressed air line, often a circuit or ring line, which has to supply various devices and consequently exhibits pressure fluctuations, indeed must exhibit them. To ensure a reliable application of adhesive/sealant, it is advisable to measure and regulate the inlet pressure. The required displays and controllers can be retrofitted on most devices and show great effect with little effort.
A newer Innotech development is a system from INNOTECH/FESTO, where the same amount of adhesive is dispensed per shot, regardless of how long the operator triggers the material flow. This is the ideal solution when automation cannot or has not yet been implemented, and a defined amount needs to be dispensed for each order. This system is also available as a retrofit kit for existing pneumatic cartridge guns. This represents another step toward the reproducibility of the application.
Which brings us to the battery-powered cartridge press: Like pneumatic presses, these do not require any physical effort from the operator, thus eliminating fatigue as a source of error, but compared to pneumatic presses, they reduce the risk of accidents because they can be used without hoses (tripping hazards). For the same reason, these cartridge presses enable processing in hard-to-reach areas or on large objects such as a truck body or a bus, when
They are "adapted" to
- the given mixing ratio (determined by the material to be processed),
- the given material viscosity, which has a significant impact on mixability (the pressure generated by the cartridge press must transport the material to be mixed in the desired quantity thru the mixer, ensuring a homogeneous mixture),
- the given cartridge mass/cartridge geometry,
- the desired or required discharge quantity per given time unit or per "shot",
- the intended application, especially considering the spatial conditions (e.g., internal sealing in tight housings).
Here, too, hand-operated, pneumatic, and battery-operated devices are available.
Especially when processing 2K material, it is important to consider the back pressure building up in the mixer when selecting the press. Especially when the two components to be mixed have very different viscosities and when the quantities of the components to be mixed differ significantly, for example, MV 25:1, the uniform advancement of the pistons must contribute to the homogeneous mixing of the two components. At the same time, the cartridge press must overcome the pressure building up in the mixer to ensure a fatigue-free, uniform, and thus safe application.
Anyone who has ever "trembled" a bead of sealant or adhesive with unsuitable equipment knows to appreciate this – and we're not talking about home "crafting" here, but about artisanal and industrial application scenarios.
The adhesive/sealant processing device can indeed not only simplify the work and thus make it more cost-effective but also contribute somewhat to reducing the rate of illness or absenteeism – two examples of this:
- When bonding floors in busses or rail vehicles (but also in office and administrative buildings), highly viscous, elastic adhesives are often used, which require the worker to be on their knees or squatting – both of which are "hard on the bones," as they say. The "Floor Dispenser" provides a solution here – the worker stands upright, does not have to bend down, and certainly does not have to work on their knees.
- A manual cartridge press with an unsuitable gear ratio requires a high amount of force, especially when processing highly viscous materials. The overstrained hand often responds with tendonitis – resulting in the employe being absent for several weeks. Similarly, the bond strength of, for example, 2K-PUR polyaddition adhesives suffers due to mixing errors caused by the constant pressure peaks when "pumping with the manual cartridge press."
In both cases, the appropriate processing equipment is significantly cheaper than the illness-related absence of one or more employes – not to mention the employer's legal duty of care.
Innotech offers over 700 different cartridge presses for the manual processing of pasty adhesives and sealants – not including special developments and customer-specific modifications. Why? To provide you with THE RIGHT processing device for your application, the device that is right for the material to be processed and the adhesive or sealing task to be performed, thereby contributing to a controlled and reproducible application.
