Kraft Board COBB Value: Why Moisture Causes Packaging Failure | Case Study
- Omnia Papers LLP
- Feb 5
- 3 min read
In industrial packaging, kraft board failure rarely happens suddenly. Most failures begin quietly — with moisture.
Many manufacturers select kraft boards based on GSM, plybond, or BF, assuming thickness and bonding will protect their product. But when packaging enters humid warehouses, monsoon transport routes, or coastal regions, another factor silently takes control: COBB value.
Understanding COBB value is essential if your drums, core pipes, or industrial packaging must survive real-world conditions — not just factory inspection.
What Is COBB Value (Moisture Absorption)?
COBB value measures how much water a kraft board absorbs within a fixed time period. In simple terms, it tells you how your packaging behaves when exposed to moisture.
COBB value becomes critical in:
Humid and monsoon climates
Long-distance road or sea transport
Chemical and pharmaceutical storage
Coastal and high-moisture zones
👉 Low COBB = low water absorption = better strength retention
What many buyers don’t realize is this:
A visually strong kraft board can lose 30–40% of its strength after absorbing moisture.
And this loss often happens after dispatch, not inside the factory.
Why COBB Value Matters in Industrial Applications
High moisture absorption directly affects performance in:
Kraft board drums stored in warehouses
Core pipes exposed to humidity
Export packaging
Chemical and pharma drums
When COBB value is high, moisture enters the board layers and causes:
Board softening
Loss of BF (bursting strength)
Edge collapse
Adhesive failure
Reduced stacking strength
The packaging may look fine initially — but real failure starts once moisture exposure begins.
Case Study: How High COBB Value Caused Kraft Board Drum Failure
Client Background
The client is a fiber drum manufacturer in North India, supplying drums to chemical and pharmaceutical companies. Their packaging is used for powders and granular materials, where structural stability and safety are non-negotiable.
Since drums travel long distances and are stored in warehouses for extended periods, exposure to humidity and seasonal weather changes is unavoidable.
Problem Faced
Despite using kraft board with:
Adequate GSM
Acceptable plybond
…the client experienced repeated quality failures during storage and transportation, especially in humid conditions.
Key issues included:
Drum walls becoming soft after moisture exposure
Loss of rigidity during warehouse stacking
Cracking and deformation during transport
Rising customer complaints during monsoon months
At dispatch, the drums appeared strong. But once exposed to moisture, performance dropped sharply.
Investigation & Root Cause Analysis
Omnia Papers LLP conducted a detailed evaluation of the kraft board being used.
The findings were clear:
The kraft board had a high COBB value
Moisture penetrated rapidly into board layers
Absorbed water reduced burst strength and stiffness
Over time, this led to structural weakness and failure
The most critical insight:
COBB value was never specified or controlled.
The board was non-guaranteed, leading to batch-to-batch variation in moisture resistance. Although GSM and plybond were within limits, moisture absorption destroyed real-world performance.
How Omnia Papers LLP Solved the COBB Issue
Instead of increasing GSM or redesigning the drum, Omnia Papers LLP addressed the root cause — moisture absorption.
Step 1: Moisture Exposure Assessment
Evaluated warehouse humidity levels
Studied transit duration and exposure points
Step 2: Optimized Kraft Board Selection
Recommended a low-COBB, guaranteed kraft board, ensuring:
Controlled moisture absorption
Consistent batch performance
Recommended specification included:
Low COBB value kraft board
Guaranteed quality
Balanced GSM suitable for drum applications
Step 3: Quality Consistency & Supply Control
Defined moisture resistance parameters
Ensured stable quality across all supplies
Results Achieved
After switching to low-COBB kraft board:
Drums retained stiffness in humid conditions
No softening or deformation during storage
Improved stacking strength in warehouses
Sharp reduction in moisture-related complaints
Better product safety and customer confidence
Operations during monsoon became smooth and predictable.
Key Learning for Buyers
This case highlights a critical reality:
Moisture absorption silently weakens kraft board
GSM and plybond alone are not enough
COBB value must be controlled, especially for chemical and pharma packaging
In the next blog, we’ll explain:
👉 How to identify high COBB kraft board before it fails 👉 COBB vs BF: which matters more in humid conditions? 👉 Common buying mistakes that increase moisture risk
Because in kraft board packaging, water doesn’t break products immediately — it breaks trust first.
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