Foam fitness products look like commodity items and are sold on two numbers a buyer cannot see in a photograph: density and compression set. A roller at 45 kg per cubic metre feels soft in the shop and collapses within a month of daily use. A block at the same density loses its corners and stops being a block.
We produce EVA foam rollers, yoga blocks and moulded massage tools in Changzhou, with density and surface texture specified per SKU rather than as a house standard.
Density and what it changes
Roller density sets both the pressure and the lifespan. At 60 kg/m3 a textured roller holds its shape through repeated body weight and gives useful myofascial pressure; at 45 kg/m3 the foam compresses too far and the pressure spreads out, which is comfortable but does little. Yoga blocks sit around 50 kg/m3, firm enough that a hand pressing on the block does not sink into it.
Specification
| Roller | 33 x 14 cm, hollow bore or PP core, grid or smooth surface |
|---|---|
| Block | 23 x 15 x 7.5 cm, bevelled edges, EVA |
| Massage stick | 45 cm, PP shaft with five moulded TPE rollers |
| Density | Roller 60 kg/m3, block 50 kg/m3, custom 40 to 90 |
| Colour | Solid, two-tone, or a printed surface film |
| Packing | Polybag with header, or a printed carry strap |
| MOQ | 500 pieces per SKU |
Compression set
The test that matters is compression set: compress the foam by 50 percent, hold it, release, and measure how much thickness comes back. A good EVA recovers above 90 percent. Cheap foam recovers in the low 80s and visibly flattens where the body weight sits. We test a sample from each production lot and hold the result with the shipment record.
Texture and surface
A moulded grid or nub pattern is formed in the tool, not cut afterwards, so the pattern depth stays consistent across the roll. Cutting a pattern into a finished roller leaves a rough edge and exposes cells that fill with sweat and cannot be cleaned. Where a buyer wants a printed logo, we recommend a debossed mark rather than a print, because print on EVA wears off within weeks of handling.
Market and compliance
These are fitness accessories, not medical devices, and the copy is kept to that boundary: no therapeutic or injury-treatment claims. Foam is tested for phthalates and heavy metals where the destination market requires it, and any product-level certification is arranged by the buyer. Rollers ship compressed in some configurations to save freight, and we flag the recovery time on the carton where that option is used.
