A rotary tablet machine is a mechanical device that has several tooling stations which rotate to compress granules/powder mixture into tablets of uniform size, shape (depending on the punch design) and uniform weight.
It was developed to increase the output of tablets. In a rotary tablet machine, the compaction force on the fill material is exerted by both the upper and lower punches leaving the powder granules to be compressed in the middle.
This is known as the accordion type of compression. The capacity of a rotary tablet press is determined by the rotation speed of the turrent and the number of stations on the press.
Advantages of a Rotary Tablet Machine
- There is High productivity with a minimal amount of labor while saving money.
- Rotary press has an output of between 9000 – 234000 tab/hour thus saves time and meets up with the high demand of tablet dosage form.
- The powder filled cavity can be managed by a moving feeder automatically.
- Rotary press decreases waste of valuable formulation in non-specific tablets.
- The machine allows independent control of both weight and hardness.
- Rotary tablet machines utilize Modern and advanced technology. Excellent mechanical elements help to minimize tablet faults like capping, laminating, and picking and sticking.
Disadvantages of a Rotary Tablet Machine
Just like everything that has an advantage, it does have a few disadvantages. Here are the disadvantages of a rotary tablet machine.
- It is very effective and expensive, when it comes to sourcing it, it is not cost effective or economical.
- Technical know-how is essential while using a multi-station rotary tablet machine. This is due to the fact that it contains numerous built-in automatic mechanisms.
Additionally, the pills that are being crushed are readily contaminated. This is so because a liquid lubricant is used in the lubrication system.
- The spillage of the lubricant into the die-punch could contaminate the pills.
- Only massive manufacturing is relevant for this machine. It is not cost-effective for small-batch manufacturing.
Component of the Rotating Tablet Machine
Hopper: The hopper holds the powder mixture that is to be compressed into tablets. It facilitates the easy flow of the ingredients into the compression point.
Die cavity: This is where the power mixture is compressed in and it determines the size , the diameter and to an extent the thickness of the tablet.
Feed paddle: this helps to force the feeds into the dies especially during faster rotation
Punches : They move within the die to compress granules into tablets. It is made up of both the upper and the lower punches.
Lower cam track : This guides the lower punch during the filling stage so that the die bore is overfilled to allow accurate adjustment.
Cam tracks: This helps to guide the movement of both the upper and lower punches. That is, it controls filling, compression, and ejection of the formed tablets.This part of the machine helps in making sure the tablets produced are almost faultless.
Dept of fill/capacity control: This adjusts the lower punch track during the latter part of the fill stage to ensure that the appropriate quantity of granules remains within the die prior to compression
Recompression rollers: This roller gives the granules an initial compression force to get rid of excess air that might be entrapped in the die.
Main compression : This roller applies the final compression force needed for the formation of tablets. This part of the machine provides enough force required to compress powder into tablets.
Ejection cam: This Guides the lower punch upwards facilitating the ejection of tablets from the die cavity after compression.
Take-off Blade : This is located in front of the feeder housing and it deflects the tablet into the discharge chute.
Discharge chute : This is where the tablet passes through for collection after being deflected by the take-off blade.
Touch Screen Control Panel: This is a computerized part that allows you to control all the operations of the production of tablets. It can be directly attached to this machine or it can be used separately.
Sealing System: This part of the machine seals the tablets and helps in managing dust and preventing cross-contamination.
Electric Motor, Gear, and Belts: These are components of this machine that must move for it to function. For instance, the die, punch, turrets, and compression rollers.
The gear, belt and others have to move for the die, punch to be able to move. These movements are made possible through induction or servo motors. The filling system uses a servo motor because it can easily be controlled for accurate filling.
A synchronized motor is ideal for providing a good speed for both pre-compression and the main compression process.
The belt and gear are useful in transferring the rotation to other parts of the machine. Therefore, the application of electrical, mechanical, and hydraulic systems in this machine is very important..
Lubrication Systems: Because the machine is made up of moving parts, it’s bound to wear and tear due to friction over time.
Therefore, it’s imperative to lubricate the moving components frequently. For the automated machine, it has a central lubrication system that will automatically lubricate the rotating parts.
Hydraulic Pump Unit: This part maintains the required pre-pressure and main pressure that will ensure a smooth and accurate compression process of tablets. Apart from this, it can automatically stop the machine when it is overloaded.
How to Clean a Rotating Tablet Machine
It is very important to clean the rotating tablet machine because it will help in maintaining the hygiene of the products, seeing that the product that it is producing is quite sensitive. Here is an explanation of how it should be cleaned.
- Make sure you switch it off and unplug it from power. You don’t want to be hurt by power surge or any related causes.
- Remove all the residues of powder granules in the hopper, turret top, and other places.
- You can now take off the larger top and the gravity hopper.
- Using a paper towel with a 95% ethanol solution, clean all the parts of this machine.
- Disassemble the right side door and the top punch and detach the upper punches.
- Pull out the bottom punch casing access port and spin the turret to the initial station.
- Using an alley key, unfasten the die locks and lodge the longer punch installation rod through the bottom access port.
- Spin the shaft and align the succeeding stations to the access ports. Repeat this for all the punches.
- Remove the lower punches, spin the turret to the initial station, and place your hand below the bottom access port. This will enable you to hold the punch as it falls and unfasten the leaf spring for the bottom punch.
- Remove the plastic holding the plug and keep it in a corner.
- Rotate the shaft and align the succeeding stations to the access ports and repeat this for all the lower punches.
- You can now remove the dies and arrange them according to the stations and the bottom access ports.
- Unfasten the die lock to ensure it’s at the same level as the barrel.
- Lodge the long die installation rod through the bottom access port and hit it gently upwards till it comes out.
- After this, spin the associate blue shaft and align the next station in line to the access port. Repeat this for all the dies.
- clean all the disassembled dies and punches, Using the 95% ethanol and paper towel.
- You can also clean all the die boreholes using the paper towel with ethanol. After this, put them on a clean surface.
- Once this is done, you can put back the small access ports for both the bottom and top punches.
- Return the feeders mount plate and turret guards in place.
- Place back the top punch take-out plate and the side cabinet door.
- Lastly, shut the glass window, place the gravity hopper, and the large machine covering back and you have a clean and ready rotating tablet machine.
Conclusion on the Rotary Tablet Machine
This machine is used for compressing powder granular into tablets of different sizes, shapes, thickness, and weight.
The rotating tablet machine is used by many industries. For instance, it is used by pharmaceutical industries to produce tablets and vitamins.
It’s also used by cosmetics, confectionery, and herbal industries. As expensive as it can be, it is very effective and essential for production.
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