What Is a Powder Dispenser?
A Powder Dispenser is a sophisticated device specifically designed to accurately dispense a predetermined volume of powder. It falls under the category of automatic dispensing systems and is also known as a powder feeder or powder dispenser. These devices are commonly used in laboratories and the pharmaceutical industry, particularly for dispensing small amounts of powder, such as in milligram units.
Uses of Powder Dispensers
Powder Dispensers are primarily used in fields requiring precise powder dispensing related to chemistry and biology. They are employed in testing and research, the pharmaceutical industry, medical fields, the cosmetics industry, chemical engineering, and the food industry. These devices are used to accurately dispense minute quantities of powder, typically in milligram or microliter units, and commonly handle substances like:
- Pharmaceutical ingredients
- Reagents and raw materials for chemicals (such as resins or salts)
- Food ingredients like powdered milk or soy milk
- Food additives and seasonings
- Dental amalgam powders
- Agar and glass beads for biological and biochemical experiments
- Silica gel
- Veterinary powders
- Fish feed
Depending on the device, substances of various granularities, including powders, granules, and beads, are often processed.
Principle of Powder Dispensers
Powder Dispensers typically work by ejecting filled powder to achieve accurate dispensing. Some use a mesh plate to manually sieve a set volumetric amount of powder into a microplate.
Filling the Powder
The method of filling powder varies by device, including manual filling into the dispensing head or devices equipped with powder suction functionality. In dispensing head systems, the heads are interchangeable, allowing for the quick processing of multiple materials in different quantities without the need for cleaning, thus preventing cross-contamination.
Dispensing
Dispensers operate either by volume or mass units, with manual systems generally dispensing by volume. For example, manual systems might fill powder into a cavity at the tip and use a plunger to eject it. Electric systems can dispense rapidly, with each dispensing action taking about 3 seconds, and are capable of continuous ejection.
Device Design
Devices come in various designs, including handheld and benchtop models. Electric benchtop models can perform automated dispensing using racks of microtubes, vials, or well plates.
Mesh Plate Method
In the mesh plate method, a well plate is placed under the mesh plate, and powder is filled onto the mesh with a slider inserted between the mesh and well plate. After filling the mesh plate with the correct amount of powder and removing excess with a scraper, the slider is removed to dispense the powder into the well plate below.
Types of Powder Dispensers
There are various types of Powder Dispensers, and selecting one appropriate for the application is essential. Volume-based dispensers typically accommodate powder volumes from 5 to 1000 μl. Mass-based dispensers commonly work with milligram quantities, with some capable of dispensing from 5 to 300 mg, and others up to 25 g.
Both electric and manual dispensers are available, with electric models particularly suited for automating large-volume dispensing. Some devices can also integrate with peripheral equipment for automated material mixing, reagent preprocessing, and cap opening/closing. While microtubes, vials, and well plates are commonly used dispensing containers, compatibility varies by device, and some may only accept specific containers. Additionally, while some Powder Dispensers are designed solely for powder, others can handle various solids, including granules and beads.