Automatic or semi-automatic capsule fillers are usually either tamping pin or dosator types. If you’re buying one, you want to understand its operation first. This article explains how a dosator capsule filling machine works, which is today’s most used type.
What Makes a Dosator Capsule Filling Machine Different?
Dosator capsule fillers rely on a piston-loaded tube (dosator) to measure and compress the fill material. We call this method the dosastor principle. The machine is also either an intermittent type or continuous.
Tamping pin capsule filling involves a series of pins, usually five. The pins compress material inside a cavity in turns, ensuring sufficient amounts and weight consistency.
Another difference is the automation level. Dosator fillers are usually either automatic or semi-automatic. In contrast, a tamping pin capsule filling machine can only be automatic.
You can use a dosator filler to encapsulate medicines and supplements or package cosmetics and industrial chemicals. Other uses include packing agricultural products, veterinary drugs, and more.
Key Parts of a Dosator Capsule Filling Machine
Before examining the dosator capsule filling process, let’s understand the various parts that make it. The machine is usually automatic and complex, as outlined below.
Fill Material Hopper and Feeding Unit
The fill material hopper holds the substance that needs encapsulating. The material can be a powder, granules, pellets, or medicine tablets. The hopper sends the material down the feeding unit and onto a powder bed during filling.
Capsule Hopper and Feeding System
This hopper holds unfilled capsules before they can go down to the filling station. On the other hand, the feeding unit changes their directions to prepare them for filling.
Dosing Pin and Plunger
The dosing pin measures the fill material, ensuring accuracy and maintaining material weight consistency. The pin has a space at one end and a moving piston on the other.
Setting the plunger higher increases the amount of material. Setting it low reduces the cavity space and, therefore, the material. The piston also compresses the powder, holding it inside the cylinder.
Filling Bed and Dosing System
The filing bed holds the substance, allowing dosing. The dosing unit holds the plunger-loaded pins that descend onto the filling bed. It fills the powder or other material, moving automatically without manual intervention.
Capsule Locking and Ejection Mechanism
The locking mechanism rejoins the caps and bodies, sealing them as required. After sealing, the ejection system removes the filled capsules from the line, sending them to a collection point.
Other Parts
The machine also has motors, drive systems, sensors, and controls. It also has an electrical, lubrication, and vacuum system to support its operation. Automatic types have rails and conveyors. These help users to integrate it with other sections of a production line.
How a Dosator Capsule Filling Machine Works
The dosator capsule filling for powder is a 6-stage process. It comprises these steps: pre-compression/incoming phase, compression, retraction, doctoring, filling, and ejection. The steps below explain the various stages and more.
Stage 1: Feeding Powder into Dosing Bed
- The required amount of powder leaves the hopper
- The material goes to the powder bed
- Empty capsules also move down the rectification system
Stage 2: Dosator Moves into Powder Bed
- The dosing tool moves down, forcing powder into its cavity
- The cavity is the space between its tip and the piston
- This part is the pre-compression stage
Step 3: Compacting and Plug Formation
- The piston moves down the dosing tool, compressing the powder
- This action forms a slug, holding the powder inside the dosing cavity
- The compaction force varies from 10-150N
Step 4: Scraping Excess Powder (Doctoring)
- The dosing tool moves up and out of the powder bed
- A scraper cuts off part of the plug hanging out of the tool’s tip
- This action removes excess powder, ensuring consistent filling weight
- We call the procedure doctoring
Step 5: Ejecting Plug into Capsule
- The dosing segment rotates, moving to the side with capsules
- The plunger pushes the compressed powder into the capsule body
Step 6: Capsule Sealing and Ejection
- In another section, the machine rejoins the caps to the bodies
- It also seals and ejects them
- Meanwhile, another cycle has already begun
- This cycle will follow the above steps
What are the Advantages of Dosator Capsule Filling?
The machine has many benefits, especially since it’s automated and highly accurate. Likewise, it has some drawbacks and limitations. Let’s start with the advantages before exploring the downsides.
High Precision
Accuracy is one of the most significant benefits of dosator and other automatic machines. The adjustable dosing tube precisely measures fill amounts, with 5-10 gram weights possible.
Enhanced Versatility
This machine can fill various material forms, including powder, granules, pellets, and tablets. Mechanisms vary based on the material type. However, the dosing principle still applies.
Increased Consistency
The plunger ensures the dosage remains equal for consistent material amount and weight. That’s because its position remains constant. Other reasons include the automated processes that provide precise repeatability.
Greater Adaptability
It has numerous settings that allow you to adjust filling parameters. You can change its tooling components to make it encapsulate various capsule sizes.
Dosator Capsule Filling Drawbacks
The dosator working principle has a few downsides. They include complexity, material limitation, and machine maintenance requirements. Let’s examine these factors and how they can influence your decisions.
Complex Operation
The complex machine operations are less friendly to beginners. For instance, you need specialized training to operate one. The machine also requires a qualified professional to service or fix it.
Limited Materials
You can only use it for dry materials and capsules. As such, you would also need a different machine to fill liquid or semi-solid materials like pastes.
Higher Maintenance Needs
It has many moving parts and complex mechanisms. These need constant servicing and lubrication. The machine also uses advanced software and electronics. These require more attention and updates, making the machine demanding to care for.
Choosing a Dosator Capsule Filling Machine for Your Business
How do you ensure the type of filler you go for is perfect for your business and other requirements? We compiled a list of the considerations to make.
1. Choose between an automatic and semi-automatic type: they have varying prices and mechanisms. Automatic types are faster and more convenient. They also allow integration with larger systems.
2. Find a device that can fill your specific “type of capsule” and size to avoid incompatibility issues. You can find this information in the machine’s specifications list.
3. Select a speed that meets your production requirements. Some are faster than others, with variations that reach several thousand capsules per hour.
4. Features and add-ons also vary. Therefore, go for a machine that satisfies your application. Examples include auxiliary equipment like polishers and capsule inspection devices.
5. Ensure the machine follows industry standards, and mainly those enforced in your part of the world. These include safety-based standards like cGMP, RoHS, and FDA requirements.
Conclusion
The dosator capsule filling machine is the most used today, especially by the pharmaceutical industry. The machine utilizes a unique tube fitted with a plunger to measure and dispense material. This action ensures filing precision. In other words, your products will have consistent weight, reducing rejected pieces and improving product quality.
