20 Common Tablet Press Machine Defects and Solutions

Producing perfect tablets is not easy. Whether you’re in pharmaceuticals, nutraceuticals, or other industries, tablet press machine defects can disrupt operations, waste materials, and compromise product quality. 

But here’s the good news: understanding these issues and their solutions can save you time, money, and headaches. Let’s explore the most common tablet press machine defects and how to address them effectively:

1. Capping

Capping happens when the top or bottom of a tablet separates during or after compression. Capping defect often arises due to improper bonding during the compression process. 

Alt-text: A capsule with the top and bottom separated and the content spilled

Solution:

• Adjust compression force and pre-compression settings to improve bonding.
• Ensure proper granule moisture levels to maintain cohesion.
• Use appropriate binders in your formulation to enhance the integrity of the tablet.

2. Lamination

Lamination occurs when a tablet splits into multiple horizontal layers, often due to insufficient bonding during compression. 

Solution:

• Decrease tablet press speed to allow more time for particle bonding.
• Increase dwell time to ensure proper compaction.
• Optimize granule size distribution to promote uniformity.

3. Sticking

Sticking happens when the powder adheres to the punches or dies, often due to excessive moisture or inadequate lubrication. 

Solution:

• Ensure punches and dies are clean and polished to reduce surface adhesion.
• Use anti-adherent agents like magnesium stearate to minimize sticking.
• Adjust formulation to reduce tackiness and improve flow properties.

4. Picking

Picking refers to material sticking to the engraving or logo on punches, leading to defective tablets with incomplete markings. 

Solution:

• Use punches with a smoother surface or specialized coatings to prevent picking.
• Apply proper punch lubrication to reduce adhesion.
• Modify the formulation to reduce moisture content and enhance flowability.

5. Binding

Binding occurs when granules stick to the die wall, causing operational delays and damaged tablets. 

Solution:

• Reduce compression force to decrease stress on the material.
• Apply more lubricant to the formulation to ensure smooth flow.
• Clean and polish the die regularly to maintain its functionality.

6. Mottling

Tablet press machine defects can also lead to mottling, similar to mottling in paint. Mottling is the uneven coloring on tablet surfaces, which can affect the aesthetic appeal of the product. 

Solution:

• Ensure uniform mixing of colorants in the formulation to avoid inconsistencies.
• Use light-resistant coatings for sensitive materials prone to discoloration.
• Reduce heat exposure during processing to maintain color stability.

7. Flashing

Flashing refers to thin, unwanted edges forming around tablets, often caused by poor alignment of punches and dies. 

Solution:

• Align punches and dies correctly to prevent material overflow.
• Reduce compression force to minimize edge formation.
• Inspect and replace worn punches or dies as necessary.

8. Chipping

Chipping involves the breaking or flaking of tablet edges, which can compromise the tablet’s integrity and lead to tablet breaking.

Solution:

• Lower compression force to reduce stress on tablets during production.
• Ensure proper tool alignment to avoid uneven pressure.
• Use harder tooling materials to withstand wear and tear over time.

9. Cracking

Cracking happens when visible lines or fractures appear on tablets, often due to high compression force or inadequate formulation. 

Solution:

• Decrease tablet press speed to reduce impact and stress.
• Increase granule moisture content for better compaction and flexibility.
• Use plasticizers to improve tablet elasticity and reduce brittleness.

10. Double Impression

Double impression occurs when the tablet shows overlapping logos or engravings, leading to inconsistent branding. 

Solution:

• Use punches with anti-turning features to maintain alignment.
• Ensure the upper punch is properly secured during operation.
• Regularly inspect and calibrate the machine to maintain precision.

11. Black Spots

Have you noticed black spots on your tablets? Black spots on tablets are often due to contamination during the manufacturing process. 

Solution:

• Clean all machine components thoroughly between batches to remove contaminants.
• Inspect raw materials for any impurities before use.
• Use high-quality tooling with non-reactive coatings to prevent discoloration.

12. Inconsistent Thickness

Another issue caused by tablet press machine defects is inconsistent thickness. Thickness variations can compromise tablet uniformity and dosing accuracy. 

Solution:

• Regularly calibrate the tablet press machine to maintain consistency.
• Monitor granule size and ensure consistent feeding into the die cavity.
• Adjust compression force as needed to achieve uniform thickness.

13. Twining

Twining occurs when two or more tablets stick together during production, often due to high moisture levels or insufficient lubrication. 

Solution:

• Ensure sufficient lubrication in the formulation to prevent adhesion.
• Decrease compression force to reduce tackiness between tablets.
• Regularly inspect punches and dies for wear and replace them as needed.

14. Hardness Variation

Hardness inconsistencies affect tablet durability, packaging, and dissolution rates. 

Solution:

• Maintain consistent granule size distribution to promote uniform bonding.
• Adjust compression settings to achieve the desired hardness levels.
• Regularly monitor machine settings and recalibrate as necessary.

15. Weight Variation

Weight variation can lead to dosing inaccuracies, regulatory non-compliance, and customer dissatisfaction. 

Solution:

• Ensure consistent granule flow into the die cavity by using proper feeders.
• Regularly check and adjust the fill depth to maintain uniformity.
• Maintain machine components to prevent irregular feeding and blockages.

16. Dusting

Dusting results in excessive powder residue on tablet surfaces, affecting their appearance and handling. 

Solution:

• Use dedusting equipment after tablet compression to remove excess powder.
• Ensure proper granule binding during formulation to minimize dust.
• Regularly clean the machine to prevent powder accumulation and contamination.

17. Brittleness

Brittle tablets are prone to breaking during handling, packaging, or transport. 

Solution:

• Increase binder content in the formulation to enhance cohesion.
• Reduce compression force to avoid over-compaction that leads to brittleness.
• Use granules with optimal moisture levels to improve tablet flexibility.

18. Uneven Coating

Uneven coating affects tablet aesthetics, taste masking, and functionality. 

Solution:

• Ensure uniform application of coating material during the coating process.
• Optimize the drying process to avoid streaks or uneven finishes.
• Use high-quality coating equipment for consistent results across batches.

19. Underfill

Underfill occurs when tablets contain less material than required, leading to non-compliance and inefficiencies. 

Solution:

• Calibrate the feeder system to ensure accurate fill levels for each batch.
• Monitor granule flow to prevent blockages in the feeder system.
• Inspect and replace worn feeding components regularly to maintain accuracy.

20. Improper Lubrication

Improper lubrication can cause sticking, binding, or other defects during production. 

Solution:

• Add the correct amount of lubricant to the formulation to reduce friction.
• Use high-quality lubricants suited to your materials and machine specifications.
• Regularly clean and maintain lubrication points on the machine to ensure smooth operation.

Tablet Press Machine Defects: Final Thoughts

Tablet production is a delicate balance of precision and quality control. Understanding and addressing these tablet press machine defects ensures smoother operations and higher-quality products. 

By taking proactive measures, you can significantly reduce downtime, avoid defective tablets, and produce consistent, high-quality tablets. 

Ready to upgrade your equipment and minimize defects? Explore high-quality tablet press solutions at Canaan’s product page or contact us for cutting-edge technologies designed to optimize your operations.

Resources

• Causes and Remedies of Lamination in Tablet Manufacturing
• How to solve Tablet Chipping