Every supplier sends a spec sheet. Very few use the same fields in the same units, which is why two quotes that look alike can be 30% apart on cost per absorbed litre. This guide walks through the numbers that actually move the price, and the order to read them in.
Start with grams, not adjectives
A diaper is sold by name and bought by weight. "Ultra-soft premium" tells you nothing about what is inside the bag. The first number to find is total weight in grams per piece, then SAP loading in grams. Those two figures, not the branding, decide what the product can absorb and what it costs to make.
A useful sanity check: at the same absorbency target, every extra gram of SAP adds cost roughly in proportion, while extra fluff pulp adds bulk and weight without much capacity. If a supplier quotes a heavy diaper with a low SAP number, you are paying for pulp.
SAP loading is the second number
Superabsorbent polymer is the most expensive component in most diaper constructions. Economy tiers typically run around 4 g, volume tiers around 6 g, and overnight or premium tiers around 8 g. Ask for the number explicitly, in grams, per size. A sheet that gives only "high absorption" is hiding the one figure that determines both performance and price.
Absorption should be in millilitres
Absorption capacity is usually stated in millilitres per piece, measured by a defined test method. Insist on the method: free swell, centrifuge retention and demand absorbency give very different numbers for the same core. If two suppliers quote "600 ml" without a method, you cannot compare them. Ask which standard they test to and whether a third-party report exists for the batch.
Rewet and acquisition time matter as much
Absorption capacity tells you how much the core can hold. Rewet tells you how much comes back to the skin under pressure, and acquisition time tells you how fast liquid disappears from the surface. A diaper can hold 800 ml and still feel wet in ten minutes. For baby and adult products, ask for rewet in grams and acquisition time in seconds; those two numbers predict complaints better than capacity alone.
Price the product per 100 ml, not per piece
Per-piece price hides the product. A USD 0.038 piece absorbing 400 ml costs 0.95 cents per 100 ml. A USD 0.058 piece absorbing 800 ml costs 0.73 cents per 100 ml: more expensive on the shelf tag, cheaper per unit of performance. Distributors who compare only per-piece prices almost always overpay for the low tier and under-buy the high tier.
Five numbers to request from every supplier
- Total weight per piece, in grams, by size
- SAP loading, in grams, by size
- Absorption in millilitres, with the test method named
- Rewet in grams and acquisition time in seconds
- Price per 100 ml, calculated from the four numbers above
Any supplier who cannot produce all five is guessing, and you will discover it in the first claim.
What to do with the answer
Once the numbers are on one page, the commercial conversation gets shorter. You can decide which tier fits your shelf price, which sizes to lead with, and where a cheaper construction is genuinely safe rather than quietly worse. Send us your target shelf price and destination market, and we will return a spec that hits it, with these five numbers filled in.
