Tablet Counter For Dusty Products: Handling Transparent And Irregular Dosage Forms

A tablet counter for dusty products requires stable product separation and reliable detection performance. The main factors to evaluate are dust control, feeding behavior, and sensor or camera accuracy for the actual dosage form. Equipment selection should be based on representative product testing rather than nominal counting speed alone.

Why Dusty, Transparent, Irregular, and Sticky Products Cause Counting Errors

Counting errors usually begin before the product reaches the counting sensor or camera. If tablets or capsules do not enter the detection zone as separate, predictable units, even a capable counting system may produce unstable results.

Four material characteristics deserve particular attention.

Product Condition	Typical Symptom	Possible Cause	Confirmation Test	Potential Action
Dusty tablets/capsules	Intermittent overcount or undercount	Dust deposits on sensor, lens, reflector, or guide surfaces	Run a controlled dusty sample and inspect optical surfaces before/after the test	Improve dust extraction, cleaning access, sensor protection, or feeding conditions
Transparent capsules/softgels	Missed counts or unstable detection	Low optical contrast or light transmission/reflection changes	Test transparent samples under actual lighting and sensor settings	Evaluate optical sensing, lighting, camera exposure, or detection algorithm
Irregular tablets	Double feeding, bridging, unstable count	Non-uniform geometry changes orientation and flow	Compare round and irregular samples at the same feed setting	Adjust vibration, channel geometry, separation, or product path
Sticky/gummy products	Product overlap, sticking, intermittent feed	Surface tackiness causes adhesion or bridging	Run samples after conditioning at representative temperature/humidity	Modify feed conditions and verify separation before increasing speed
Mixed sizes or shapes	Variable feed rate	Product flow behavior changes between batches	Run each SKU separately and compare flow stability	Establish product-specific settings or changeover parameters

These symptoms should not be treated as proof of a sensor failure. A count problem can originate in the hopper, vibration system, guide channel, detection zone, bottle positioning system, or control logic.

For this reason, a material-compatibility test should examine the complete path from bulk loading to final count.

Dust: The First Variable to Investigate

Tablet dust can accumulate around feeding channels and optical components. The effect depends on particle size, dust loading, product formulation, surface properties, machine geometry, and cleaning frequency.

For a conventional photoelectric counting system, contamination can affect the optical path between the emitting and receiving components. A dusty environment can also change how products separate, because fines may alter surface friction and flow behavior.

A useful diagnostic sequence is:

1. Record the normal count error and operating conditions.

2. Inspect the feed channels and detection area.

3. Clean the relevant optical and product-contact surfaces according to the equipment procedure.

4. Repeat the same sample test.

5. Compare the count result before and after cleaning.

6. If the error returns progressively, investigate dust generation and accumulation rather than repeatedly recalibrating the sensor.

A dust-resistant design can reduce this sensitivity, but "dust-resistant" should not be interpreted as "maintenance-free." The acceptable dust load must be established through testing with the actual formulation.

SED Pharma's electronic counting equipment uses photoelectric detection and provides product-contact and cleaning-oriented design features on applicable models. Its SED-8S page also identifies an optional dust collection arrangement and anti-jam features for specific applications.

The practical selection question is therefore not simply whether a counter can count dusty products. Ask:

How does the detection system behave after the same dust exposure that occurs during your actual production run?

How Transparent Capsules and Irregular Tablets Affect Detection

Transparent and irregular products create different detection challenges, so they should not be grouped under a single "difficult product" category.

Transparent Capsule Counting

Transparent capsules or softgels can be difficult for optical systems because the detected signal depends on how light passes through, reflects from, or is scattered by the product.

Color, shell thickness, fill material, surface finish, and lighting geometry can all affect the result. A transparent capsule that is easy to detect under one optical arrangement may behave differently after a formulation or shell change.

For transparent capsule counting, the evaluation should use representative production samples rather than substitute materials. The test should consider the actual capsule size, normal feeding conditions, product orientation, dust or fines generated during handling, and the proposed sensor or camera configuration. Repeated counting cycles are also necessary because a single successful demonstration does not represent long-term detection stability.

Do not validate transparent products using opaque samples and assume the result will transfer.

If a camera-based system is being considered, lighting and image processing become additional variables. Camera exposure, illumination direction, background contrast, product orientation, and image-processing thresholds can influence whether the capsule boundary is consistently recognized.

Vision-based counting systems can provide additional options for products where traditional optical detection becomes difficult. However, the effectiveness depends on factors such as image contrast, lighting conditions, product orientation, and recognition performance under actual production conditions.

However, published compatibility should still be treated as a starting point for qualification, not a substitute for a product-specific test. The final operating boundary should be established with the actual sample.

Irregular Tablet Counting

Irregular tablets create a mechanical problem as much as a detection problem.

Irregular tablets can affect both feeding stability and detection consistency. Their asymmetric geometry may change how they move through the vibration channel, how they separate from neighboring tablets, and the position at which they enter the detection area. These variations can result in unstable orientation, product overlap, inconsistent sensor signals, or different image profiles between counting cycles.

This means that simply increasing vibration amplitude may not solve an irregular counting problem. Higher vibration can improve separation in one product but increase bouncing, collisions, or uncontrolled orientation in another.

The correct approach is to identify whether the error occurs before detection or during detection.

If two tablets arrive together, investigate feeding and separation.

If the tablets are visibly separated but the sensor or camera misses one, investigate the detection system.

That distinction prevents unnecessary changes to the counting algorithm when the real problem is mechanical feeding.

Sticky and Gummy Products

Sticky materials, including some gummy or chewable dosage forms, present another limitation. Their surface properties can cause two units to remain in contact or adhere temporarily to a guide surface.

A gummy counting machine therefore needs to be evaluated for both counting and product handling.

Sticky or gummy products require evaluation of both material properties and machine handling conditions. Factors such as surface tackiness, temperature, humidity, storage conditions, coating characteristics, product geometry, vibration settings, and contact surfaces can influence whether products separate consistently during feeding.

These parameters are product-dependent. A machine setting that works for one gummy formulation should not automatically be transferred to another.

If temperature or humidity affects tackiness, the test should reproduce the intended production environment or define a controlled conditioning procedure. Any resulting parameter range should be verified against the actual equipment, product, and validation requirements.

How to Test a Tablet Counter Before Equipment Selection

A product sample test should reproduce the conditions that create the counting problem. A small quantity of clean, perfectly uniform samples is not enough when the production material is dusty, transparent, irregular, or sticky.

A practical test protocol can use five stages.

1. Define the Product Sample

• Product type
• Tablet or capsule dimensions
• Weight range
• Shape
• Surface condition
• Transparency or opacity
• Coatin
• Dust generation characteristics
• Tackiness
• Normal storage and handling conditions

Where available, provide representative production samples rather than laboratory samples with different surface characteristics.

2. Measure Feeding Behavior

Before judging counting accuracy, observe whether the product reaches the detection zone as individual units.

Record:

• Bridging
• Overlap
• Product bounce
• Channel blockage
• Orientation changes
• Product damage
• Feed-rate instability

If the product cannot be separated consistently, the problem is primarily a material-handling issue.

3. Test Detection

Once stable separation is established, test the actual detection system.

For photoelectric systems, observe:

• Sensor response
• Optical contamination
• Product transparency
• Detection consistency
• Sensor alignmen

 

For vision systems, evaluate:

• Image contrast
• Product boundary recognition
• Lighting uniformity
• Product orientation
• Overlapping-product recognition
• False detection and missed detection

The test should use repeated runs rather than one successful cycle.

A project-specific record can use a structure such as:

Test Parameter	Recorded Value
Product	[Insert product name]
Dimensions	[Insert verified dimensions]
Sample quantity	[Insert verified sample quantity]
Dust condition	[Define representative condition]
Product temperature	[Insert test condition]
Relative humidity	[Insert test condition]
Feed setting	[Insert actual machine setting]
Counting speed	[Insert actual test speed]
Count result	[Insert verified result]
Missed counts	[Insert verified result]
Overcounts	[Insert verified result]
Product damage	[Insert verified observation]
Test repetitions	[Insert verified number]

 

The test conditions should be agreed before the trial. Speed, vibration, temperature, humidity, and other parameters are not universal specifications; they must be evaluated against the specific product, equipment configuration, and validation conditions.

4. Test the Worst Reasonable Condition

If the production process creates dust, the sample should represent that condition.

If transparent capsules are used, test the transparent capsules.

If the product is irregular, test the actual irregular geometry.

If the product becomes sticky at a defined environmental condition, the test should consider that condition.

The objective is not to create an artificially difficult test that the product will never encounter. It is to avoid approving equipment based only on ideal samples.

5. Establish the Operating Boundary

After completing the test, define the operating range where the counting performance is acceptable. The final report should record the verified product, machine settings, environmental conditions, test results, and any limitations identified during evaluation.

This information helps procurement and engineering teams understand not only whether the equipment works, but also the conditions required for stable operation.

Which Counting Technology Should You Consider?

For difficult products, technology selection should follow the failure mechanism.

Requirement	Conventional Photoelectric Counting	Vision-Based Counting
Regular opaque tablets	Often suitable	Suitable
Dusty products	Requires dust-management evaluation	Requires lens/camera contamination evaluation
Transparent capsules	Requires optical compatibility test	Requires lighting and image-contrast test
Irregular tablets	Requires feed and sensor testing	Requires feed plus image-recognition testing
Sticky/gummy products	Strong focus on mechanical separation	Strong focus on separation and image separation
Product inspection during counting	Limited by sensor architecture	Can support image-based recognition depending on system
Product-specific tuning	Sensor and feed settings	Feed, lighting, camera, and software parameters

 

This does not mean vision counting automatically solves every difficult-product application.

A camera cannot reliably compensate for two sticky products arriving as one inseparable mass. Likewise, a sophisticated image-processing system cannot eliminate dust that physically obscures the camera or changes the product flow.

The selection decision should therefore consider the complete system:

bulk feeding → separation → product presentation → detection → counting logic → rejection/control

SED Pharma provides both photoelectric and vision-based counting solutions for different solid dosage applications. For example, photoelectric counting systems are commonly used where stable product separation and reliable optical interruption are sufficient, while vision-based systems can be considered when product recognition and image processing become important factors.

For a product with uncertain optical or mechanical behavior, these technologies should be evaluated against the same sample and acceptance criteria rather than selected from the product description alone.

A Practical Material-Compatibility Checklist

Before approving a counter for a difficult dosage form, procurement and engineering teams should confirm the following.

For a practical material-compatibility assessment, procurement and engineering teams should confirm that representative product samples are available and that product dimensions, weight range, dust generation, transparency, irregular geometry, and tackiness have been documented. Feeding stability should be evaluated independently from counting accuracy, while sensor or camera performance should be checked after representative product exposure. The test speed, machine settings, test repetitions, missed counts, overcounts, product damage, and operating limitations should also be recorded. Any parameter changes that could affect product quality or validation status should be controlled through the site's applicable procedures.

 

A useful sample submission should include the product itself together with basic technical information. Sending only the product name makes compatibility assessment less reliable because different formulations, coatings, sizes, and surface properties can behave differently.

Send Samples Before Finalizing the Counting Solution

Difficult products should be treated as a material-compatibility question rather than a specification-sheet question.

SED Pharma can support this evaluation by reviewing the product characteristics, intended counting application, and proposed equipment configuration. Its counting-machine range covers tablets, hard capsules, softgels, pills, irregular tablets, and other solid products, while its vision counting solution provides an alternative approach where image-based recognition is technically appropriate.

 

The most useful information to provide for an initial assessment includes:

• Representative tablets, capsules, softgels, or gummy samples
• Product dimensions and approximate weight range
• Whether the product is transparent, opaque, coated, or irregular
• Known dust or fines generation
• Known sticking or bridging behavior
• Required counting quantity
• Target production rate
• Current counting problem, if replacing existing equipment
• Photos or videos of the current feeding and counting issue
• Relevant environmental conditions
• Confirm Equipment Compatibility Before Final Approval.

The test should establish how the product feeds, separates, presents to the sensor or camera, and performs at the intended operating conditions.

Conclusion

Selecting a tablet counter for dusty products requires more than confirming a nominal tablet or capsule size range. Dust can affect optical detection and maintenance, transparent products can change the optical signal, irregular tablets can destabilize feeding and orientation, and sticky products can create overlap before detection occurs.

The correct selection sequence is:

Characterize the material → observe feeding → test detection → reproduce difficult conditions → record actual results → define operating limits → approve the equipment.

For transparent capsule counting, irregular tablet counting, or gummy products, representative sample testing is especially valuable because material behavior can vary significantly with formulation, surface condition, dimensions, environmental conditions, and machine settings.

The final acceptance decision should be based on verified test results and documented operating boundaries, with any changes that may affect product quality or validation status handled through the applicable SOPs, risk assessments, and validation procedures.

A tablet counter for dusty products is suitable only when its feeding and detection performance have been demonstrated for the actual material and conditions that matter in production.