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Laboratory stirrers and shakers from JOANLAB

35 families of laboratory stirrers and shakers from JOANLAB: heating magnetic stirrers, magnetic stirrers, multi-position stirrers, stirring baths, stirring accessories, overhead stirrers, homogenizers, vortex mixers, microplate shakers, rotary mixers, orbital shakers, and reciprocating, rocking and 3D shakers. Models, configuration and availability are confirmed in the quote.

35 product families

Where the torque comes in

The first decision is not volume: it is how the torque reaches the vessel. In a magnetic stirrer, a rotating field under the plate drags a bar that sits inside the beaker. The coupling acts at a distance and has a ceiling, which drops with the thickness of the base and with the height of the liquid.

When the resistance of the medium goes past that ceiling, the bar falls out of step, jumps and stops mixing. Nothing on the unit gives it away: the bar is the only part not joined to the motor. An overhead stirrer transmits the rotation through a submerged shaft and cannot decouple; in exchange it takes up vertical space above the vessel. The three overhead families on this page are the only ones whose datasheet declares nominal torque.

Mixing and breaking up are not the same thing

A stirrer moves the liquid in bulk to even out concentration or temperature. A homogenizer does something else: it concentrates the work in a very small space, where the liquid is put under an enormous velocity gradient. That is shear: it breaks up agglomerates, forms emulsions and dissipates energy inside the liquid itself.

It is not faster mixing, it is a different process, and one of short cycles: it is worth checking whether the datasheet declares a maximum continuous running time. A vortex mixer takes a third place, with a small amplitude at high frequency at the bottom of the tube: it turns the contents over in seconds. Many are used that way, in pulses, but not all of them are short-cycle: the platform and multi-tube formats declare continuous running and timers of up to 8 or 24 hours, so if the process is a long one it is worth looking at the timer on the datasheet before ruling them out.

Hot plate, cooler liquid

A hotplate regulates its own surface; the liquid trails behind it, by a difference that is not fixed. It depends on the contact with the base, on the thickness of the glass, on the volume and on the stirring itself, which spreads out a heat that comes in through a single point.

Setting the plate to the value you want in the liquid does not get you there. To control on the medium you need a probe inside it: it is worth checking whether the datasheet declares one, and not confusing the tolerance on the liquid with the tolerance on the plate.

On a platform, amplitude governs

A platform shaker does not touch the liquid: it moves the vessel and lets inertia do the work. The movement has an amplitude of its own —the orbit diameter when it is orbital— and what you adjust is the speed. A large, slow amplitude moves the whole volume of a flask; a small, fast one shakes the contents of a well, where there is no room for a long travel.

Whatever goes on top has to be held down, because the platform accelerates and brakes on every turn. And there is a weight ceiling: among the families on this page that declare a maximum load, none goes beyond 5 kg. The catalog does not spell out what that load includes.

Worth having on hand before requesting a quote

The real volume you are going to stir and the viscosity of the medium at working temperature; if it thickens during the process, the value that decides is the one at the end.

The vessel: type, base diameter and whether it is closed. And how many units in parallel, which is what separates a single station from a multi-place unit.

Where it ends up installed: several datasheets declare an ambient temperature range for use, and it is worth looking at if the unit is going to work in a cold room. Voltage and availability are confirmed in the quote.

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