Our board: materials, testing and recyclability
The board is recycled kraft, GSM-verified and burst-tested by batch. Every Vikrama Industries box starts as recycled kraft paper fluted into 3-ply, 5-ply or 7-ply board. We verify the GSM, test bursting strength on each batch, and design for recyclability. This page defines the terms plainly and states the honest limits, so you know what the board does and what it does not do.
What the board is
Our board is corrugated recycled kraft paper. Flat outer and inner liners sandwich a fluted middle layer, and the flute is what gives corrugated board its stiffness and cushioning. More layers mean more walls and more strength. 3-ply is single wall, 5-ply is double wall, 7-ply is triple wall.
The weight of the paper is measured in GSM, grams per square metre. Heavier paper and more plies raise the GSM and the strength. Our figures are about 420 g/sqm for 3-ply, about 700 for 5-ply and about 980 for 7-ply. These are typical values, not fixed constants, because recycled kraft varies with the batch.
GSM means grams per square metre. Our board runs about 420 g/sqm at 3-ply, 700 at 5-ply and 980 at 7-ply.
| Term | Plain meaning |
|---|---|
| GSM | Grams per square metre. The weight of the paper per square metre. Higher GSM means heavier, stronger board. |
| Ply | The number of paper layers in the board. 3-ply is single wall, 5-ply is double wall, 7-ply is triple wall. |
| Single wall (3-ply) | One fluted layer between two liners. Light to mid-weight goods. |
| Double wall (5-ply) | Two fluted layers. Mid-weight and fragile goods. |
| Triple wall (7-ply) | Three fluted layers. Heavy, dense or bulk loads. |
| Flute E | A fine flute about 1.5mm tall. Smooth surface, good for print. |
| Flute B | A flute about 3mm tall. Firm, common for retail boxes. |
| Flute C | A flute about 4mm tall. Good cushioning and stacking. |
| Flute BC | A B and C combination about 7mm tall, used in double wall for extra strength. |
| RSC | Regular slotted carton. The standard box where all flaps are the same depth and the outer flaps meet in the middle. |
| Bursting strength | A batch-tested measure of how much pressure the board takes before it ruptures. |
| Kraft paper | Strong paper made from wood pulp. Ours is recycled kraft, reused fibre rather than fresh pulp. |
| Recyclability | Whether the board can be reprocessed after use. Plain corrugated is recyclable when kept clean and dry and free of heavy coatings. |
How the board is verified and burst-tested
Recycled kraft is not uniform. Fibre length and moisture shift from batch to batch, and that changes both weight and strength. So we do not assume the board is right. We check it.
- GSM is verified against the target for the ply, so the board weighs what it should.
- Bursting strength is tested by batch, so a weak run is caught before it becomes your boxes.
- Ply and flute are matched to the load: single wall for light goods, double for mid-weight and fragile, triple for heavy.
- A physical sample is approved before any production run, so you hold the actual board first.
Bursting strength is a batch-tested measure of the pressure the board takes before it ruptures.
Verification is the point. A GSM figure on a spec sheet means little unless the board in your hands matches it. Batch burst-testing is how a claim becomes a check.
GSM-verified tested board vs unverified board
Corrugated board can look identical across two suppliers and behave very differently under load. The difference is whether anyone measured it.
The honest version is that both start as recycled kraft. What separates them is the check between the mill and your dispatch.
Recyclability by design, and the honest limits
Plain corrugated recycled kraft is recyclable by design. The fibre can go back into the paper stream when the board is kept clean and dry. Two things change that: coatings and disposal. Heavy laminates, wax or plastic film can make board harder to recycle, and greasy or wet board is often rejected at collection. We keep coatings minimal and tell you when a finish affects recyclability.
We will not overstate this. Corrugated board has real limits, and a shipping decision made on false comfort costs more than an honest one.
- Plain corrugated is not waterproof. It resists brief handling but not soaking.
- Monsoon humidity weakens board. Damp air softens the fibre and lowers the effective strength, so storage matters in the wet months.
- Recyclability depends on coatings and clean disposal. A heavy plastic laminate or contaminated board may not be accepted for recycling.
| Limit | What it means | What helps |
|---|---|---|
| Not waterproof | Plain board wicks water and loses stiffness when wet | Store dry, use a liner or coating for wet routes, note the recyclability trade-off |
| Monsoon humidity | Damp air softens board and lowers stack strength | Keep stock off the floor and covered, run heavier ply in the wet season |
| Coatings affect recycling | Laminates and films can block reprocessing | Keep coatings minimal, disclose finish, dispose clean and dry |
Frequently asked questions
What does GSM mean on a box spec?
GSM is grams per square metre, the weight of the paper per square metre. Higher GSM usually means heavier, stronger board. Our board runs about 420 g/sqm at 3-ply, 700 at 5-ply and 980 at 7-ply.
What is the difference between 3-ply, 5-ply and 7-ply?
3-ply is single wall with one fluted layer, for light to mid-weight goods. 5-ply is double wall for mid-weight and fragile items. 7-ply is triple wall for heavy or dense loads.
What is bursting strength?
Bursting strength is a batch-tested measure of how much pressure the board takes before it ruptures. We test it by batch so a weak run is caught before it becomes your boxes.
Are the boxes waterproof?
No. Plain corrugated recycled kraft is not waterproof. It handles brief exposure but not soaking, and monsoon humidity weakens the board, so keep stock dry.
Is the board recyclable?
Plain corrugated recycled kraft is recyclable by design when kept clean and dry. Heavy coatings, laminates or contamination can prevent recycling, so we keep coatings minimal and disclose any finish that affects it.
What are the flute grades?
Flute E is about 1.5mm and smooth for print, B is about 3mm, C is about 4mm, and BC is a combination about 7mm used in double wall for extra strength.
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