Whether you’re a seasoned business owner or just stepping into the packaging world, understanding corrugated board grades is essential.
From reducing packaging costs to enhancing product protection, the right cardboard can make all the difference.
Dive into this comprehensive guide to master the types of cardboard and elevate your packaging game.
Composition of Material
How Is Corrugated Material Formed?
Corrugated cardboard is a powerhouse in packaging, but how is it made? A standard sheet of corrugated cardboard consists of three main components:
- Fluted Material (Flutes): The wavy middle layer that provides strength.
- Outer Liner: The sturdy paper on the outside.
- Inner Liner: The protective paper on the inside.
During manufacturing, the fluted material is glued to both the outer and inner liners.
This bonding process adds rigidity and stability, ensuring your packages are both strong and reliable.
Types of Paper
Material Used in the Manufacture of Cardboard
The type of paper used in corrugated cardboard significantly impacts its strength and cost. Here are the primary paper types:
Kraft Paper (K):
- Source: Made from softwood trees.
- Benefits: Strongest type, easy to print on.
- Usage: Commonly used for the outer liner.
Test Paper (T):
- Source: Made from recycled fibers.
- Benefits: Cost-effective but less strong than Kraft.
- Usage: Typically used for the inner liner.
Other Paper Grades:
- CHIP (C): Waste-based liners.
- Fully Bleached White (BW): High-quality, bleached Kraft.
- White Top (WT): White-coated recycled liner.
- Mottled Kraft (MK) & Oyster (OY): Decorative options.
- Semi Chem (SC) & Waste Based (WB): Specialized uses.
Understanding these paper types helps you choose the right material for your packaging needs, balancing cost and performance.
Paper Weights & GSM
Variances Between Papers Used
GSM (Grams per Square Meter) measures paper weight. Higher GSM means thicker, stronger paper. Common GSM weights for corrugated material include:
- 115/125 GSM
- 140/150 GSM
- 185/200 GSM
- 300 GSM
For example, a 125 GSM Kraft paper liner is often labeled as 125K. Choosing the right GSM ensures your packaging meets both strength and cost requirements.
Wall Types
Construction of Corrugated Cardboard Material
Corrugated cardboard can have different wall types based on the number of flutes:
- Single Wall:
- Structure: One layer of flutes between two liners.
- Use: General packaging needs.
- Double Wall:
- Structure: Two layers of flutes with three liners.
- Use: Heavier items requiring extra protection.
- Triple Wall (Tri-Wall):
- Structure: Three layers of flutes with four liners.
- Use: Very heavy or large items like automotive parts.
Selecting the appropriate wall type ensures your products are well-protected during transit.
Flutes
Explanation of Corrugated Flutes
Flutes are the wavy layers that give corrugated cardboard its strength. Different flute types offer varying levels of performance:
- E Flute (1.5mm): Fine flutes, excellent for high-quality printing and lightweight cartons.
- B Flute (3mm): Versatile, suitable for most packaging needs.
- C Flute (4mm): Greater compression strength, ideal for lightweight products.
- BC Flute (6mm) & EB Flute (4.5mm): Double wall flutes for enhanced protection and strength.
Flute type affects both the durability and print quality of your packaging. Choose the flute that best matches your product requirements.
Board Grade Naming
Corrugated Board Descriptions Explained
Understanding board grade naming helps you identify the right cardboard for your needs. The format typically follows:
[Outer Liner GSM/Type] / [Flute Type] / [Inner Liner GSM/Type]
Examples:
- 125K/B/125T: 125 GSM Kraft outer liner, B flute, 125 GSM Test inner liner.
- 150T/E/150T: 150 GSM Test outer liner, E flute, 150 GSM Test inner liner.
This naming convention ensures clarity when selecting materials with specific strength and cost characteristics.
Applications
Individual Flute Uses
Choosing the right flute type is crucial for different packaging applications:
- E Flute:
- Use: High-quality prints, small cartons, die-cutting.
- Benefit: Excellent compression strength and crush resistance.
- B Flute:
- Use: Versatile for various packaging needs.
- Benefit: Good all-round performance.
- C Flute:
- Use: Lightweight products needing higher stacking strength.
- Benefit: Better compression strength.
- BC & EB Flute:
- Use: Shipping boxes requiring high transit protection.
- Benefit: Enhanced strength and print finish.
Selecting the right flute type ensures your packaging performs optimally for its intended use.
Weights
Flute Type Weight Tables
Different board grades support varying product weights. Here’s a quick reference:
B or E Flute:
- 125 K/T: 4-6kg
- 150 K/T: 8-12kg
- 200 K/T: 12-17kg
- 200 K/300 T: 17-25kg
- 300 K/T: 25-35kg
BC or EB Flute:
- 125 K/T: 10-15kg
- 150 K/T: 15-25kg
- 200 K/T: 25-35kg
- 200 K/300 T: 35-40kg
- 300 K/T: 40-45kg
Use these guidelines to match your packaging needs with the appropriate board grade.
Terminology
Technical Terms Associated with Corrugated Board Grades
Familiarize yourself with key terms to navigate the corrugated cardboard industry effectively:
- Across Flute: Measurement across the flute’s width.
- Backing Liner: Compressible paper material enhancing appearance and strength.
- Blank: Flat piece of corrugated board ready to be made into a box.
- Board Grade: Classification based on liner weights, flute type, and inner liner.
- Burst: Packaging failure due to excessive pressure.
- Carton Board: Stiffer, thicker than boxboard, used for paper cups and plates.
- Crush: Resistance to being flattened.
- Double Wall Board: Two layers of corrugated material for extra strength.
- Edge Crush Test: Measures board’s resistance to vertical crushing.
- Tri-Wall: Triple fluted board for maximum strength.
Understanding these terms will help you make informed decisions about your packaging solutions.
In Summary
Understanding Corrugated Board Grades
Choosing the right corrugated board grade is vital for ensuring your packaging is cost-effective and performs well.
By understanding the composition, paper types, GSM, wall types, flutes, and board grade naming, you can select the perfect cardboard for your needs.
Need Expert Advice?
If you have questions or want to ensure your packaging uses the most cost-effective material, contact a design engineer at Pakoro today. Elevate your packaging strategy with the right corrugated board grade!
