The objective of all tablet/capsule counting machinery is essentially the same. Bulk product must be distributed to containers in specific quantities. Machine manufactures have attempted to accomplish this objective utilizing many methods since the first automated tablet/capsule counter was designed. Electronic counters and slat counters have emerged as the industry standard. A large number of manufacturers have produced electronic counters. This article will discuss how to determine which might best fit a particular application.
Speed : Speed is among the top concerns that must be taken under consideration. Most electronic counters will claim speed output in terms of bottles per minute (BPM). Manufacturers typically use an aspirin size tablet (1/4” Diameter X 1/8” Height) with 100 tablets per bottle to measure BPM. It is also important to note that a packaging line is only as fast as its’ slowest piece of equipment. Therefore, if a packaging line contains a machine that only completes 30 bottles per minute; the filler does not need to exceed this speed. Many variables dictate the top speed that a machine can complete a fill cycle. Product manipulation, Design quality of the counting apparatus and the number of containers filled simultaneously have the greatest overall effect on speed.
Accuracy : Accuracy is in some cases the most important function of the counting machine. The FDA mandates that tablets and capsules that fall under its’ jurisdiction must be counted as means of determining the quantity per container. Most electronic fillers accomplish this by detecting a tablet or capsule as it free falls past a sensor or camera system. The sophistication and capabilities of these counting systems varies greatly from machine to machine. The higher end the machine, the more likely it will have a more sophisticated and capable counting system.
Simple systems use a sensor (usually an off-the-shelf name brand sensor, not specific to the application) to determine that there was a change in signal and will count this change as a good tablet. Complex systems will use customized sensor assemblies or cameras to detect a tablet or capsule on multiple planes and collect and analyze data from each object that falls through the counting system. These systems can usually determine if the product that fell through is whole or broken, or if two or more products fall through the system simultaneously the system can identify it as two or more tablets, whereas a simple system would count that instance as one product. The higher end counting systems typically have faster communications and reset times allowing for faster throughput of product without sacrificing accuracy due to lag time errors.
Change-over time / Parts : Another important consideration is changeover. One of the biggest benefits to an electronic filler is that it does not require a large number of product or container specific change parts. This keeps costs down even if a large number of different products are filled by the same machine. Container funnels are typically the only change part required with electronic counters, but different manufacturers may have additional change parts required to run different products.
To avoid cross contamination, machine parts that come into direct contact with the product must be cleaned between runs. This is a time consuming process that cuts into the overall production of the packaging line. It is therefore important that the tablet filler can be disassembled quickly and easily. Most machines will allow contact parts to be removed without the use of tools. This saves valuable time and allows operators, who may not be comfortable with tools, to disassemble the machine for cleaning. The breakdown of each machine differs significantly. This is an important aspect to the global functionality of the machine.
Packaging facilities will often have multiple sets of contacts parts, so that one set can be used for production while others are being cleaned. Having multiple sets of contact parts can save substantial time during change over from one product to another. This does increase the cost; some machines have many contact parts and require thousands of dollars in investment to own. The number of contact parts may be a consideration to the end user.
Cleaning : All machines must be cleaned between product runs. While contact parts are normally removed for cleaning, other areas of the machine may require cleaning as well. Some machine designs have accounted for this with flush surfaces and large access areas. Other machines do not address this issue with design features. A machine that is difficult to fully clean can create problems for packaging facilities.
Some machines in the industry will make available mobile stations specifically designed for a particular machine’s contact and change parts. This allows for easy parts management, as well as easy cleaning. The mobile stations are designed so that the entire station can be washed down and all parts will be orientated for optimal exposure. Most packaging facilities have cleaning procedures, a well designed machine, in this respect, can improve efficiency.
Durability : A tablet / capsule filler is a major purchase for a packaging line. It is extremely frustrating and disappointing when a relatively new piece of equipment fails. In an effort to keep costs down, some machine builders will use inexpensive components and materials in their machines. Over time these components and materials breakdown, as they often have a lower cycle life or are stressed beyond their intended use. It is important to select a machine that has a robust build and uses higher quality components.
Footprint : Packaging lines occupy a large amount of space in a facility. Smaller footprint machines are a benefit to a line layout as they allow the packaging line to be smaller and contain more equipment, which adds capability. As a general rule smaller machines operate slower. It is important to balance the commodity of space versus the need for speed. Most tablet counters are designed to be as compact as possible, but some machines have a greater footprint to output ratio than others.
Machine Maintenance : All machines require maintenance. Another advantage to electronic fillers over slat fillers is that electronic fillers have far fewer moving parts. This translates to less required maintenance and parts replacement. Most machines will have recommended preventative maintenance schedules. This can be useful in determining how high or low maintenance a machine will be. It is also important to be sure that the machine has good access points to all areas of the machine. Access to unauthorized areas of the machine should be restricted without the use of tools so that unapproved personnel, cannot tamper with the machine.
Safety : Electronic tablet counters have relatively few moving parts, so safety concerns are not as great as they are on other machinery. A few areas for concern might be the Shutter assembly, Electrical cabinet, and bottle indexing system. These areas should have proper guarding and warning decals. The importance of safety in any machine should not be overlooked.
Product Manipulation : All electronic tablet counters have a bulk product hopper from which tablets start the passage through the machine. Most fillers will move the product out of the hopper using vibration. Separation is a very important aspect of product manipulation as tablets and capsules should fall through the counting system single file. This will limit the opportunity for counting errors. Product should flow smoothly and as quickly as possible from the hopper, and achieve the required separation prior to entering the counting system.
Once the product is counted it must be grouped as a “complete count” and dispensed into a container. More advanced fillers will have multiple staging areas that “complete counts” will transfer through before being dispensed. This allows for continuous motion filling, providing for better overall efficiency.
Reject Method : Broken tablets will be introduced to all electronic fillers. It is an unavoidable problem that most higher end electronic counters can account for. Higher end counting systems can determine when a broken tablet or possible miscount have passed through the counting system. Most fillers will track this “bad count” to the container, and reject the container as it exits the machine.
A few electronic fillers on the market can reject “bad counts” before they enter the container. This ensures that only correctly filled containers exit the machine. This is a safer rejection method as it eliminates the possibility of sending a “bad count” down the packaging line.
Machine Operation : Operation of each tablet counter will differ from one manufacturer to another. Some important features to note are as follows:
-Recipe parameters / memory- Most machines will allow end users to enter many product specific parameters to best tune the machine to run that particular product. The more parameters, the more control, too many parameters can cause issues as well if the operator becomes confused. Once the parameters are defined, most machines will allow the end user to save this recipe. Machines do have limits as to how many recipes can be stored. Some machines also allow for recipes to be exported or imported as well.
Self teach- Some machines will allow the end user to run a few products through the count system and the machine will learn the size and shape of the product. It will use this data to determine what to look for as it counts product during production.
User management : It is important for a machine to have a user friendly interface. Most well developed electronic counters will have an intuitive HMI with simple navigation. Security features such as user logins and controlled access throughout the system is a benefit.
Data Management : Data, such as reject and error tracking is imperative to understanding what is happening on the packing line.