Development and improvement of rotary table press have come a long way.
Previously, we had hand driven tablet press which has over time undergone development to electrically driven machine.
The results of the advancements in the design of the tablet compression machine are efficiency, greater flexibility, and minimized tablet variation.
If you want to venture in this form of oral dosage (tablet compression), then this guide is for you.
It covers everything about rotary tablet compression machine – from the basic definition, advantages, working principle, technical specifications, and many other critical aspects.
Without further ado, let’s dive right into the main subject of this guide:
- What is a Rotary Tablet Press Machine?
- Standards for Tablet Compression Tooling
- Classification of Rotary Tablet Press Tooling
- Advantages Rotary Tablet Press
- Disadvantages of Rotary Tablet Press
- Functional Parts of a Rotary Tablet Press
- How Rotary Tablet Press Machines Works
- Clean-up Procedure of Rotary Tablet Press
- Maintenance and Lubrication of Rotary Table Press Machine
- Features and Technical Specification of Rotary Tablet Press
- Application of Rotary Tablet Press in Pharmaceutical Industry
What is a Rotary Tablet Press Machine?
Tablet press is also known as a pharmaceutical tablet press, tablet compression machine, tableting machine, or tablet punching machine.
It is a mechanical equipment that compresses powders into tablets of consistent size, shape, and weight.
Tablet compression machine
The resultant tablets contain approximately the same amount of Active Pharmaceutical Ingredient (API) and excipients.
Apart from its application in the pharmaceutical industries for producing varieties of tablets, you can equally use it in the manufacture of cosmetics, cleaning products, and illicit drugs.
All tablet compressing machines employ a similar basic principle of compression.
There exist two types of tablet presses namely:
This is the simplest tablet compression machine.
At times you may as well refer to it as eccentric press, or single station tableting machine.
Based on its design, you may operate it manually or install an electric motor.
Usually, this equipment entails a single tooling station having a die, and pairs of a bottom and top punches.
Single punch tablet press
Due to this fact, the compression force of the tablet punching machine is because of the top punch only.
During the process of compression, the bottom punch stays stationary.
This means that the operation process seems to be the same as that of the hammering movement.
It is because of this fact that you may call it a single-station punch press.
· Rotary tablet presses
Most high-speed tableting machine comes in the form of a rotating turret that carries any number of dies and punches.
As they spin about the turret, the punches get into contact with cams which modulate the vertical posture of each punch.
Rotary tablet press is a mechanical equipment that contrary to the single punch tablet compressing machine, has various tooling station.
Normally, these stations rotate to compress powder or granule mixture into tablets of consistent size, shape, and weight.
The shape of the tablets depends on the punch design.
Basically, this machine was developed to enhance the output of tablets.
Individual fabricators of rotary tablet press machines have sought to obtain higher output by;
- Raising the effective number of punches.
- Increasing the number of station.
- Expanding the number of compression points.
- Raising the speed of compression turret.
However, each of the improvements come with their merits and demerits.
In rotary tablet press, both the upper and the lower punches exert the force of compaction on the fill material leaving the powder granules you want to compress in the middle.
This is referred to as an accordion type of compression.
The number of stations on the machine and the speed of rotation of the turrets determines the capacity of a rotary tablet press.
Each application of a rotary tablet press requires custom-made punches and dies, which you can make in a broad variety of sizes and shapes.
You can customize them with manufacturer codes and scoring lines to facilitate easier breaking of tablets.
Based on the size, shape, material, and configuration of the press, a typical modern rotary tablet press can manufacture from 250,000 to above 1,000,000 tablets per hour.
Rotary tablet press compresses tablets into a uniform shape, size, and weight.
It also manufactures more tablets compared to single punch tablet presses.
These attributes make rotary tablet compression machines the preferred equipment for large-scale manufacture of tablets.
Standards for Tablet Compression Tooling
The compression tooling that is, the punches and dies determine the size, shape and identification labels of the tablet.
As a rule, the tooling must comply with certain specifications to fulfill the needs of production efficiency, dosage uniformity and aesthetic appearance.
Tablet press tooling system
With regard to punch and dies, tooling dimensions standardization has been set to minimize the number of spare parts and to enable interchangeability between tablet presses.
In most instances, a specific tableting machine is available with a variety of turrets so as to standardize tooling with a manufacturing facility.
Whenever you are planning to purchase in new rotary tablet press tooling, you will have two standard designs to select.
Globally there exist two acknowledged standards for tablet compression tooling; The EU standard and the TSM standard.
Set of tablet press tooling system
The establishment of TSM and EU tooling standards in the industry was to offer a system that guards individuals’ tooling investments while retaining established procedures and processes.
TSM and EU standards are very similar to one another though you cannot interchange them.
· TSM Standards
TSM is the short form for ‘Tablet Specification Manual’extensively recognized and solely applied in the United States.
The TSM tooling stipulations are the only published guidelines for the tablet compression industry.
It is the exclusive reference on U.S. production standards for tablet tooling and tablets.
The American Pharmacists Association (APhA) is the body that instituted it.
· EU Standard
European Standard is known as the Euronorm or EU standard.
The EU standard tool formations are not published or controlled by an association or organization.
This is the most popular tooling configuration applied outside the U.S.A.
TSM and EU standards are very similar to one another, but both differ on the basis of punch length, head thickness, and punch head.
Differences between TSM and EU Tooling Configurations
The key differences between these two tablet compressing machine tool designs are:
- Punch length in TSM standards is 0.010 inches shorter than EU standards.
- In both B and D types of tool, the head thickness is smaller in the EU tooling system than in the TSM specifications.
- The punch heads have a domed profile in EU standard while in TSM, it has an angled top profile.
- Comparing the B tooling type in EU, the internal head angle for punches is 30°while in TSM specifications it is 37°
Even though there exist little deviations between the standards, like seal grove configuration, these deviations do not hinder interchangeability.
Besides, they are not harmful to the working of the rotary tablet press.
All of these variations are surmountable.
Tablet press tooling types
In recognition of the need to eliminate these variables, the EU standard has been brought up to date to make it be in harmony with ISO standard.
ISO 18084 lays out sensible and efficient specifications for tablet press/cross-platform compatibility.
Importance of Tablet Tooling Standardization
Recent calls to merge legacy tooling standards and make them in agreement with the globally acknowledged have gotten much more extensive.
In the current global pharmaceutical industry, the majority of solid-dose firms have production facilities around the globe.
Therefore, there are several advantages of having only a single standard for tablet tooling, consisting of:
- Interchangeability between tablet compression machines of different products both in facilities and across locations globally.
- Minimized tooling inventories. This can help in cutting costs.
- Reduced lead times thanks to tooling-supplier rationalization
- Standardized procedures (for example, procurement, operation, and maintenance)
- Standardized machinery and processes for verification and inspection
- Consistent quality and grade of tooling throughout all pharmaceutical products and plants.
- Increased global technical exchange problem-solving and development.
Given these advantages, it should come as no surprise that ISO 18084 is getting acknowledgment as a suitable standard for the tablet-tooling sector.
As a matter of fact, there is proof that global pharmaceutical manufacturers, for whom the rewards for rationalization are greatest, are increasingly adopting the ISO standard.
One global tooling standard ought to be highly desirable for the pharmaceutical industry.
Nonetheless, these changes will take quite some time to evolve, even if rotary tablet press developers could be persuaded that it is in their business interest to embrace the global tooling standard.
Classification of Rotary Tablet Press Tooling
You can classify rotary tablet press into various categories though the most critical of these classifications depends on the type of tooling you are to use on the machine.
As you are aware already, a tooling set consists of the die and its related punches.
Based on the EU and TSM standards, there are mainly B and D classes of tablet tooling.
Further, there is BB classification of the B tooling dies and punches.
You can as well use the D tooling on the B tooling equipment, and you refer to this as DB tooling.
You make the subcategories of BB and DB tablet tooling depending on the dies and punches requirements of the compression process.
The table below shows the dimensions of these types of rotary tablet press tooling.
|Type of Tooling||Punch Dia. (mm)||Die Dia. (mm)||Punch Length (mm)||Max Size Round/Capsule|
· B tooling
The B tooling formation has an ordinary, punch barrel diameter of 19 mm (0.750 inches). You can apply the B type with two types of die, that is, they have two differing die sizes:
- B dies having a diameter of 30.16 mm (1.1875 inches), appropriate for all sizes of tablet as much as the maximum for the B punches.
- The smaller BB dies that have diameter of 24 mm (0.945 inches). This type of die is fit for tablets having diameter of 9 mm or maximum of 11 mm.
· D tooling
This type of tooling has a larger ordinary barrel diameter of 25.4 mm (1 inch) and a die diameter of 38.10 mm (1.500 inches).
It is appropriate for tablets having a maximum length or diameter of 25.4 mm.
· BB Tolling
A rotary tablet press tooling having a barrel diameter of 0.75 inch, length of 5.25 inches, Head diameter of 1 inch, dies external diameter of 30.16 mm.
B tooling is similar to BB with the only difference being that the lower punch has a length that is just 3 and 9/16th inch long.
· DB Tooling
This type of tooling has punch diameter and length similar to that of D tooling through the diameter of the dies differs between them.
D tooling punches and dies normally have a bigger diameter of the punches tip as compared to B type of tooling.
This makes D tooling appropriate for compression tablets of big sizes.
The design of rotary tablet presses allows them to use either B or D tooling but not both.
Here, the amount of compression force attainable in a tableting machine relies on the type of tooling you use.
Compression machine designs requiring B tooling type apply a maximal compression force of 6.5 tonnes.
On the other hand, tablet presses that use the D tooling configuration apply a compression force of 10 tonnes.
There is as well special tablet punching machinery designed with the intent of applying higher compression forces.
The highest force of compression that a tablet press can exert on a specific size and shape of tablet depends on:
- Size of the punch tip
- Maximum force the design of the machine can handle.
The choice of the type of tablet press tooling (B or D) is essential to enhance the output during commercial manufacturing.
Normally, the output will be 20 to 25% more in B tooling than in D, assuming the same diameter and speed of the turret of the compression machine as number of stations.
As you can see, die and punch set play an integral role in the tablet compression process.
For that matter, selecting a suitable design that satisfies your specific tablet making requirements is crucial.
Moreover, the standardization and maintenance of rotary tablet press tool type are important in guaranteeing maximum and efficient production.
Advantages Rotary Tablet Press
I know you have been asking yourself why a table press is a must have accessory.
Well, in this section, you will learn about the various advantages of rotary table press.
Rotary tablet press
i. High output
With rotary tablet press, you can manufacture tens or hundreds of thousands of tablet pieces per hour whereas you can only produce hundreds of pieces using a single punch tableting machine.
ii. High efficiency
As an automatic equipment, rotary tablet compressing machine could continually complete the operation of powder filling, tablet pressing and rejecting.
With the easy and humanized operation, the machine saves on time and human labor.
iii. High-quality tablets
Advanced methods and excellent mechanical components greatly reduce the chance of tablet flaws, such as capping and chipping, lamination, picking and sticking, among others.
iv. Uniform pressure
A rotary tablet compressing machine produces each tablet by pressing it from both top and bottom side using uniform pressure.
This evens and compacts the powders resulting in tight tablets, with subtle weight variation.
Different types of tablet press
Furthermore, you attach a pre-pressing gadget on each rotary tablet press which functions before main pressing.
The combination of pre-pressing and main pressing gets rid of air entrapment that may result in tablet capping.
v. Smooth surface of tablet
The punch tooling employed on rotary tableting machine needs to be of high quality or produced with special treatment.
The machine has a well-polished B and D tooling resulting in a smooth tip surface thus, smooth, good quality tablets.
vi. Hygienic operation
Stainless steel that meets the GMP requirements houses the rotary tablet press.
Transparent windows surround the working area enable you to observe the working condition clearly.
You can open the windows for cleaning and caring; this offers a sanitary condition for tablet pressing.
Disadvantages of Rotary Tablet Press
Well, a rotary tablet press machine is not 100% perfect. It has some disadvantages.
A reason why you should talk to an expert to consider this is a perfect choice for you or not.
Let’s look at some of these disadvantages:
- One main demerit of this type of tablet press machine is that it is relatively costly to purchase. However, you will get value for your money due to the efficiency offered by it.
- Another disadvantage worth highlighting is that multi-station compression machine needs a little bit of expertise considering that it has various automated systems.
- The high possibility of pollution and contamination is another shortcoming of this tableting machine. Typically, the lubrication system of the equipment utilizes liquid lubricant.
In some instances, such lubricants might spill or leak into the die-punch cavity resulting in contamination.
- Besides, rotary tablet press is not suitable for manufacturing small batches thus making it unfit for R&D projects or small-scale production.
Functional Parts of a Rotary Tablet Press
Knowing rotary tablet press components is important in the tablet manufacturing process.
For this reason, I will enlighten you on these parts by focusing on the major components that you will come across in any rotary tablet punching equipment.
Smart PLus tablet press machine
Rotary tableting presses have the following basic components:
Figure 10 Basic parts of a tablet press machine
1. The Hopper
The process of tablet compression begins here. It is through this component that you inject into the rotary tablet press all the raw material that you want to compress into tablets.
There are different varieties of tablet compression machine hoppers.
Irrespective of the shape of the hopper, it ought to allow for easy flow of the raw materials into the tablet compression chamber.
Material used to make the hopper is stainless steel.
This is because it is one section of the tablet press that gets into direct contact with the raw material.
Use of stainless steel on this component guarantees safety and hygiene of the pharmaceutical products.
Based on the design of a tablet punching machine, you can fill the raw material either manually or applying other automated systems.
When shopping for a rotary tablet press, insist on a hopper that makes sure there is a constant flow of the raw material to the compression systems.
Choose tableting machines having hoppers that have optimal flow angles to permit flow, particularly in situations where it is almost impossible to modify formulation.
In addition, certain hoppers may have vibratory rods.
These come in handy in boosting product flow and avoiding possible separation of product.
2. Feeder System
This is yet another essential part of the tableting machine.
It is important to note that, at any specific time, the design of the rotary tablet press must be in such a way that it facilitates an accurate and regular flow of powder to the punch and die system.
Section of the feeding system
The feeder system of a rotary tablet compression machine consists of two crucial components:
3. Feeder housing
The channel through which raw materials from the hopper enter the die system.
For you to produce high-quality tablets, the feeding process needs to be constant and accurate.
Here, the material used to make the feeder housing is 316L stainless steel because it gets in contact with the raw material.
Additional, stainless steel ensures that the powder does not adhere to the feeder housing since it will result in inconsistencies during the process of feeding.
4. Feed peddles
Majority of high-speed rotary tablet presses have feed peddles.
These components make sure there is constant and accurate feeding of materials into the die systems.
Tablet compression process flow
Absence of a feed peddle, papeddlesarly if the tableting machine is functioning at high speed, there could be possibilities of half filling of some dies.
This may lead to tablets with different degree of compaction or thickness.
5. Rotary Tablet Press Punches
Punches are another crucial parts of a rotary tablet compression machinery.
Usually, you have the liberty to select from simple to complex punches.
The design and shape of a rotary tablet press punch have direct effect on the quality of the tablets.
Tablet compression punches
Normal working conditions expose the punches to extremely high pressure and abrasive environments.
Therefore, they need high-quality material and if practicable with a special layer to prevent wear and sticking.
To manufacture the required tablets, the rotary tablet punches move inside the die, thus compressing the raw material into the required tablets.
In any rotary tablet compression machine, you will find:
6. Upper punch system
Like the name hints, you will find the top punches on the upper segment of the rotary tablet press machine.
They advance vertically, in and out of the die bore.
7. Lower punch system
The location of the lower punches is on, the lower segment of the rotary system of the tableting equipment.
During the process of compression, the lower punches stay inside the die bore all through the entire cycle.
8. Rotary Tablet Press Die System
In most case, whenever we discuss tablet compression machine punches, the die system is the next part that comes into picture.
Section of the die system
As stated previously, the movement of rotary tableting machine punches happens inside the die cavity or bore.
Therefore, to ensure compatibility, you must machine together with the punch and the die.
Compression of powder into wanted tablets of defined size and thickness takes place in the die cavity.
The die cavity dictates both the size and thickness of a tablet.
Same as the punches, a die system needs to have the following attributes:
- Clean impression on each punch
- Prevent destruction or chipping of tablets
- Have anti-corrosion protection
- Feature non-stick treatment
Other crucial properties that you should factor in when machining the die system of a tablet press include:
- Tapering angle which is an essential element because it facilitates escape of excess air while minimizing the frictional heat and tablet ejection force.
- Other technical specifications consist of chamfer, die bore, die height, and die diameter.
9. Tablet Press Turret
Turrets are the center of rotary tablet press tooling, and there have been plenty of advancements in the recent past relating to their designing.
Tablet press turret
The spinning turrets got holes that house the die system of a rotary tablet press.
There machining is precise to the needed rotational tolerances and dimensions.
Each bore on it ensures full alignment of the punches and dies for optimal tablet compression operation.
Moreover, to ensure efficiency and reliability, you rotary tablet compression machine should have room for any necessary modifications with regard to the tablet making process.
For this reason, most tablet press developers are moving from ordinary turrets that were mainly punches and dies, to segmented turrets having partitioned sections and punches.
A segmented rotary turret design boosts production while reducing likely downtime during the process of tablet compression.
In addition, the new design facilitates quick part changeover and increased number of tablet punching stations.
Not that, it is the turrets of the rotary tablet press that dictates the number of stations.
This assists in determining the manufacturing capacity of the compression machine for each complete rotation of turret.
Furthermore, with an appropriately designed tablet tooling system, it is possible to install the multi-tips punches easily.
This is popular in the high capacity rotary tablet presses (EU) or the Tablet Specification Manual (TSM) tooling.
On the other hand, you can as well go for custom tableting machine tooling systems.
10. Cam Tracks
These are other rotary tableting machine components that have an important purpose in ensuring a seamless tablet compression process.
The primary role of the cam tracks is to direct the lower and upper punches in different phases of the tablet compression operation.
That is, it is the cam trucks that facilitate the up and down movement of the punches as the turret rotates.
This comes in handy in the control of filling, compression, and ejection of processed tablets.
Section of cam track
For instance, powder flows in and fills the cavity as the upper cam draws out the top punches from the die.
Conversely, the lower cam track thrusts the bottom punches upwards inside the die cavity.
This leads to overfilling of the die by the raw material, enabling accurate variation of the die content.
For the rotary tablet press to attain a maximum compression force, the top cam track steers the upper punch while the bottom cam track adjusts the lower punch.
After compressing the tablet to the required prescriptions, the top cam draws out the upper punches.
On the other hand, the bottom punches move upwards to eject the compressed tablets with the assistance of the bottom cam.
In summary, you can realize that the lower and upper cam tracks play a vital role at every stage of the tablet compression in the rotary tablet press machine.
Tablet making is a simple procedure that you must precisely control to attain tablets of the desired size and weight.
11. Filling Station and Weight Control
With the aid of various motions of the cam systems, the powder will move into the cavity based on the position of the punches.
Typically, manufacturers of rotary tablet press machines apply servo motors to modulate the movement of cam tracks for correct dosing.
Section of the filling station
This is because of the motor’s high precision and ease of incorporation to other computerized systems of other machinery parts.
· Weight control
This is an essential feature of the rotary tablet compression machine.
By regulating the depth fill, tablet punching equipment can easily control the content inside its die cavity.
Usually, with the aid of the bottom cam track, the lower punch moves up to a preset height.
This ensures filling of the die cavity to a desired depth before commencing any compression process.
In some instances, there may be overflow of the excess powder as the lower punch moves up.
On that account, to prevent wastages, the extra powder automatically flows to the next die cavity that machine should be filling.
To attain these, all the other parts and components must be in smooth coordination for a seamless tablet compression process.
12. Compression Rollers
The primary goal of tablet making process is to make sure that the rotary tablet press compresses only the powder to the required size and shape.
Nonetheless, in some situations, you may find air trapped within the powder particles.
To attain this result, the tablet punching machine has a series of rollers that apply an adequate amount of force needed to compress the powder.
They first eject air before starting the process of compression.
Most rotary tablet press has two sets of rollers:
· Pre-compression rollers
These are tablet compression equipment first rollers.
They exert a small quantity of force on the lower and upper punches.
This provides the first compression force.
Here, the key role of the pre-compression rollers is to eliminate air that could be within the powder granules or the die.
Any trapped air will automatically result in poor quality tablets.
These component of rotary tablet press machine are essential due to the fact that any powder in the hopper might have air between its granules.
· Main compression rollers
Main compression rollers apply a preset quantity of force (final force of compression) for the production of the tablets.
The amount of compression force exerted by these rollers is higher than the pre-compression ones.
It is critical that the rollers stay stable without vibration during the whole process.
This is to make sure there is consistency in the size and thickness of the produced tablets.
13. Ejection Cam
The location of the ejection cam is immediately after the main compression rollers.
They are equally important parts of the rotary tablet press just like the other cam tracks.
If the machine lacks them, there is no way you will be able to access the processed tablet.
Section of ejection cam
After compression, the tablet always remains fixed inside the die systems (area between the top and the bottom punches).
The ejection cams firmly and gradually push the lower punch up.
Concurrently, the upper cams move upwards and so does the upper punches.
Consequently, the fully compressed tablet get out of the die cavity, that is, the resulting tablet stays at the top of the die.
14. Take –off blade
You will find then take –off blades installed just above the feeder housing.
They have the main purpose of deflecting the produced tablets into the discharge chute.
15. Discharge Chute
This component directs the fully compressed tablets to the collection bin after receiving them from the take-off blades.
You will realize that the 11 rotary tablet press parts discussed above primarily concentrate on the processing segment.
That is feeding, compression, and discharging phases.
Nevertheless, there exist other components that equally aid in the tablet compression.
Let’s look at these additional components that as well play a crucial role in the process of tablet manufacturing.
16. Touch Screen Control Panel
The touchscreen HMI system enables the operator to control each aspect of the tablet compression process.
You can either have the HMI attached to the tablet press or separate.
Touchscreen control panel
Majority of rotary tablet presses found in the market either use Allen-Bradley or SIEMENS PLC systems.
Since the control panel monitors every element of the tableting operation, it is a key component of the integrated computerized system.
17. Sealing System
The sealing system offers an advanced capability of managing dust.
This isolation minimizes the necessity to clean the rotary tableting machine constantly and possible cross-contamination.
18. Electric Motors, Gears and Belts
The dies, punches, turrets, compression rollers, among others, are all moving components.
This signifies that the rotary tablet punching machinery employs a prime mover (s).
Based on the type of movement you intend to create, the machine can use either an induction motor or a servo motor.
Electrical system of rotary tablet press
For instance, a servo motor is the better option for the filling system.
This is due to the ease of controlling servo-motors to achieve the greatest standards of precisions such as 0.01mm.
Nevertheless, for the pre-compression and the compression phases, using synchronous motors provide a better speed and control.
Moreover, to transfer this motion to other parts of the tablet press, you may employ a blend of both belts and gears.
The design of every rotary tablet press is in such a manner that enables the machinery to compensate any variations in load correctly.
Even the motor is capable of starting the tableting equipment, whether with no load or under maximum load.
In a nutshell, to obtain a desired motion, you need to integrate electrical, hydraulic and mechanical systems.
19. Lubrications Systems
By now you should have realized that moving parts make integral sections of the rotary tablet compression machine.
For that matter, to avoid wear and tear brought about by friction, you need to lubricate the moving parts.
Section of lubrication system
Majority of rotary tablet presses have a central lubrication system.
This system automatically oils the moving components of the compression machine.
20. Hydraulic Pump Unit
An effective hydraulic pump system will aid in maintaining constant pre-pressure and main pressure.
This makes sure there is smooth and accurate tablet compression process.
In addition, to prevent probable destruction that may take place on the tooling system of the machine, the rotary tablet press has an overloading protective unit.
It automatically stops the equipment in the event of an overload.
How Rotary Tablet Press Machines Works
A rotary tablet press is one of the most common type of compression machine and broadly utilized in the pharmaceutical industry.
It helps in the compression of powder into tablets of consistent size and weight.
In this section, I am going to briefly take you through the working principle of the rotary tablet press machine.
Different Stages of Tablet Compression Process:
The working of rotary tableting machines is categorized into four distinct stages.
They consist of:
Tablet compressing stage
Filling Overfilling of the raw material into machine
Metering Removal of excess raw material
Compression Formation of tablets by pressure of punches inside the die
Ejection Removal of tablets from the die
The filling phase of tablet compression process entails transfer of raw material in place for tablet forming.
Here, the formulation has undergone prior processing by dry granulation (roller compaction), sizing, wet granulation or other process.
The formulation then undergoes blending to give a homogeneous mix.
At this stage, you feed the rotary tablet press machine with the raw materials by placing them in the hopper.
Because to the geometrical shape of most hoppers, the formulation flows to the tableting machine punch-die cavity.
The punch-die cavity consists of the lower punch and the punch-die.
The lower punch position inside the die dictates the volume of the punch-die cavity.
You must appropriately size this volume in order to compress the weight of the powder into tablets.
The overfilling of raw materials takes place on the turret (die table) to make sure there is total filling of the volume of the punch-die cavity.
Rotary table compression process
Metering phase of the tablet compressing process entails removal of excess raw material from the rotary tablet compressing device.
This stage makes sure that you compress the exact weight (volume) of powder into tablets.
Height of the bottom punch in die controls the exact weight of the raw materials.
On the other hand, the metering cam (also known as the dosage cam) controls the height of the bottom punch.
The system raises the bottom punch to the suitable level within the die to give the exact weight of raw materials in the punch-die cavity.
Normally, the machine scrapes the excess powder from the surface of the turret.
This stage is the same as the technique applied to measure flour during cake baking.
You first overfill a measuring cup with flour; then utilize a knife to scrape off the extra.
You then leave the exact quantity of flour in the measuring cup.
The compression step of the tablet production forms the tablet.
This phase entails closing together the lower and the upper punches under pressure inside the die to produce the tablet.
Tablet compression process
As the punches move into the compressing stage, the bottom and top punches move between the two compression rollers (also referred to as pressure rolls).
The rollers close the punches together to produce the tablet.
Remember, the distance between the top and the bottom punches dictates the hardness and the thickness of the formed tablet.
If the punches are close to each other, the rotary tablet press machine will form a thin and hard tablet.
On the other hand, it will produce a softer and thicker tablet when the punches are farther apart.
Appropriate balance of hardness and thickness dictates the optimum compression roller distance for any particular product.
You make these adjustments while maintaining the tablet weight constant.
The ejection phase of the tablet compressing operation entails removal of the tablet from the bottom punch-die station.
In this step, the top punch pulls back from the die cavity and moves up above the turret.
Then the bottom moves upwards within the die, which consequently thrusts the tablet up to the upper surface of the turret and out of the die cavity.
A scraper (also referred to as tablet rake-off or takeoff scraper) then thrusts the tablet off the turret away from the tableting press into the discharge chute.
Eventually, the discharge chute releases the tablet into the collection container.
Basically, this will be the end of a single whole cycle of the rotary tablet press machine.
It implies that the turret has undergone one complete revolution.
In some instances, you may as well refer to the equipment as multi-station tablet press machine.
Clean-up Procedure of Rotary Tablet Press
Tablet punch machine
- Switch off and unplug the tablet punching machine.
- Vacuum out the powder particles from the gravity hopper, the top of the turret and all obvious
- Take out the large top covering and gravity hopper.
- Follow procedures 1-7. Cleanse and wipe every component using paper towel coupled with 95% ethanol solution.
- Take out the right side cabinet door, and the top punch take-out plate.
- Detach the upper punches:
- Pull out the casing of the bottom punch access port.
- Spin the turret to the initial station.
- Unfasten the die lock screw using an Allen key.
- Lodge the longer punch installation rod via the bottom access port.
- Spin the relevant shaft and line up the succeeding station to the access ports.
- Repeat for every punch
- Take out the lower punches:
- Spin the turret to the initial station.
- Place your hand below the bottom access port (to grasp the punch as it falls).
- Unfasten the leaf spring for the bottom punch utilizing an Allen screwdriver. Take out the plastic retaining plug. In case the punch fails to fall, drag it down towards the bottom punch access port till it drops into your hands. Pull out the punch and put aside.
- Rotate the related shaft and line up the succeeding station to the access ports.
- Repeat for every punch.
- Remove the dies:
- Arrange the first station in line to the bottom access port.
- Unfasten the die lock screw so that it is level with the barrel.
- Lodge the long die installation rod via the bottom access port and knock the die softly upwards, till it pops out.
- Spin the associated blue shaft and arrange the next station in line to the access ports.
- Repeat for every die.
- Clean all the detached dies and punches by wiping using 95% ethanol, and place them on a clean surface.
- Cleanse all the die bore holes using paper towel and ethanol.
- Put back the small access port for the bottom and top punches.
- Put back feeder mount plate and the turret guards.
- Put back the top punch take-out plate and the side cabinet door.
- Shut the glass windows, put back the gravity hopper and large machine covering.
- Put back all lubricants and tools to the toolbox. Return the toolkit in the cabinet under the rotary tablet press machine.
Maintenance and Lubrication of Rotary Table Press Machine
Maintenance and lubrication is an important procedure in tablet compression machine.
That’s why you need to learn every aspect about the process.
Rotary tablet compression machine
Let’s take a quick look how it works:
Lubrication of Tablet Compression Machine
- Recharge oil to the lubricant nozzle prior to each utilization of the tablet compressing machine. You can add more lubricant during the operation as dictated by the running speed, length of operation and temperature.
- Utilize N32 in winter and N46 oil in summer. Fill until you cover the gear to the required height, and monitor the level of oil via the glass during the compression process. Make sure you replace the oil after approximately six months.
- Apply oil using a brush before every operation to lubricate the top track disc.
- To lubricate the press track and pins, use N32 mechanical oil. Be careful not to rub in too much, since excessive quantities will spill onto the raw materials and Take care not to apply too much, as excessive amounts will leak onto the raw materials and adulterate the tablets.
Maintaining Tablet Compression Machine
Rotary tablet compression tooling system
- Continually monitor the parts, 1–2 times every month, consisting of the pressing wheel, bearing, worm, worm gear, top, and bottom tracks, camshaft.
Monitoring entails checking for clean motion of the moving components and wear.
Carry out repairs immediately you find defect.
- After compression process, remove unutilized powder and dust off excess powder from all parts of the rotary tablet press machinery.
For a prolonged shutdown, disassemble the dies and cleanse the tableting machine wholly, smear anticorrosive and envelop with a cloth shield.
- Maintain the dies in a clean state and store them in their special box, submerged entirely in oil to prevent rust.
- Clean the area of operations constantly. Specifically, avoid ash or dust contamination when producing food or medical tablets.
- Maintain and consistently monitor the electrical components. Blow the accumulated dust off the cooling fan routinely using compressed air.
- To prolong the life of the rotary tablet compressing equipment, maintain a suitable working condition having moderate humidity and temperature.
- You should let qualified personnel carry out the electrical maintenance, particularly for frequency converter. You should send it to the manufacturer if it requires repair.
- Before doing an insulation trial for the electrical components, make sure you first disassemble all the major circuit line of the frequency converter. This helps in avoiding damage.
Troubleshooting Rotary Tablet Press Machine
Compression system for tablet press
- Jitter of top/bottom pressing wheel: pressing wheel wear because of lack of lubrication. In case of little wear, fix and add lubricant. However, for serious wear, change immediately.
- Wear of upper track
- Frequently the outcome of dry wear due to lack of lubricant, leading to modest damage to the surface of the track. For serious cases, substitute the track.
- For less serious situations try lubricating the track using air compressor grease or 30” gear grease before starting the rotary tablet press machine.
- Excessive dust can result in lifting of the tableting press, causing the top track to wear. Change the formulation production process to make sure the powder constituents (beyond 100 mesh) of the formulation is not above 10%.
- Inconsistent tablet weight
- Inappropriate installation of feeder or wear can cause the problem. Replace the feeder if it is worn. Make adjustments if the problem is because of incorrect installation.
- A problem with the die could also be the cause. Inspect the height of the top/bottom press pin. Change it if it is beyond the range of tolerance.
- Never inject wet raw material into the rotary tablet press.
- If obstruction or other issues come up during the compression process, never remove tablets using hand when the compressing machine is running. This may result in personal injury.
- Refrain from putting on loose clothing when handling the rotary tableting machine.
- In case of damage, stop operating the tablet punching machine immediately until after you have adequately repaired it.
Features and Technical Specification of Rotary Tablet Press
Before purchasing and table press machine. Y
ou need to review some features and technical specifications.
This way, you will get a machine that meet your specific industrial needs.
Features of Rotary Tablet Press
Rotary tablet compression machines feature very compact design.
It has no electrical cabinet since the machine housing encloses all the electrical components.
This makes the machine take up very little space in the production room
316L stainless steel forms all the contact parts of tablet compressing machine.
Moreover, you can easily move the machine.
Control panel of modern rotary tablet press apply the newest computerized system fully remote from the visual system.
There is full integration and linkage of the Human Machine Interface (HMI) with a controller.
The multi-station tablet compression machine set of features is authentically impressive, with benefits that no other comparable machine can rival.
Normally, the motor generates up to 80Kn of pressure.
This gives it the power to produce industrial amounts of perfectly shaped tablets having up to 12mm width and 6 mm depth.
It also inscribes the tablets with crisply carved characters or a logo.
Some rotary tableting machines provide the alternative of attaching double layered, two-color equipment, etc.
That is, for manufacturers who desire to form striking tablets having strong commercial appeal.
The machine enables you to manage:
- Tablet size
- Motor speed
- Tablet depth wholly via simple electronic controls
Having comprehensive warning lights to alert the operator. Additionally, an automatic cut out system makes sure there is safe application of the immense pressure produced by the machine.
A four-sidedglass shield fullyencases the turret, boosting safety of the operator safety, and blockingairborne cross adulteration of the raw materials. For easy cleaning and access, you can open the shield on all sides.
The rotary tablet press guarantees efficient utilization of the powder courtesy of a vacuum driven suction unit.
Remember, a suction device sucks the surplus powder from the die region and takes it back for reuse.
Apart from being efficient with regard to preventing wastage, this as well minimizes the cleaning required to manage the flying powder and minimizes the hazard of blockage interrupting production.
This type of tablet press requires simple maintenance, thanks to the innovative, semi-automatic lubrication system found inside a sealed unit at the bottom of the machine.
Apart from saving a lot of time, the feature also minimizes the possibility of oil contamination and the build-up of heat.
Furthermore, it makes sure there is smoothing operation and minimized component wear.
The rotary tablet press machine is a serious component of manufacturing plant that functions exactly as you would want, considering:
- Advanced design
- High-quality fabrication
As impressive as the tableting machine is, the over 100,000 tablets every hour headline rate is barely half the story.
You also need to factor in the minimized maintenance time brought about by the vacuum powder recycling system, groundbreaking lubrication system, among others.
With regard to general productivity, rotary tablet press is thus exceptionally efficient.
In spite of its power and exceptional speed of manufacturing, the rotary tablet compression machine is very easy to operate.
This is due to its all-electronic controls and alert console.
Everything you should be aware of is right before you, and anything you ought to modify is within your reach.
You do not need to fiddle about with wrenches to regulate the output, or struggling to remember the screws that require tightening.
By just turning a dial makes all the adjustments fast and efficiently.
This implies you have more time to supervise the quality of your produced tablets and to maintain the rotary tablet press filled with raw material and operating smoothly.
Technical Specifications of Rotary Tablet Press Machine
|Punch and die type(EU)||D||B||BB||BB|
|Number of press station||45||55||69||75|
|Max tablet diameter(mm)||25||16||13||13|
|Max abnormal prolate axis size||25||18||16||16|
|Max filling depth(mm)||20||18||18||18|
|Max main pressure(KN)||100||100||100||100|
|Max pre pressure(KN)||20||20||20||20|
|Idle load noise dB(A)||<75|
|Power||380V 50HZ 10.5-13KW|
Application of Rotary Tablet Press in Pharmaceutical Industry
The tablet press forms the tablets based on a pre-determined design.
Punches and dies in the device help to shape the tablets.
These equipment produce tablets for various industries; nonetheless, the most extensive application of rotary tablet presses is pharmaceuticals and vitamins.
Applications of rotary tablet press
Tablets produced for human consumption require a design that looks attractive and easy to ingest.
Tablet compression tooling as well applies tablets coatings to make them easier to consume to prevent dissolution.
Even though the pharmaceutical industry is the biggest recipient of tablet compression machines, there are a variety of high-speed industrial rotary presses.
The machines are particularly for a range of uses, such as nuclear fuels, ferrites, nutraceuticals and food, hygiene and body care, detergents, catalysts, automotive, consumables, powder metallurgy, and electronics.
We all need a tablet punching machine that ensures optimal performance with the least downtime, safe to operate, and gives the highest level of uniformity and accuracy.
You can only acquire such a tablet compressing machine if you got an extensive knowledge of the numerous technical specifications.
Whenever you are shopping for a tableting machine, you should take into account the structural design, type of dies, punches, and turret, safety, press configuration, and automation technology.
By factoring in all these, I am quite sure that you will easily enhance productivity thus a high possibility of registering significant profits.
Though there exist various types of tablet punching machines, the clear and straight forward operation concept still stays the same.
If you want to buy a tablet compression equipment that has a fully automated system and high production, then rotary tablet press machine is your best choice among the many option you have in the market.