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Shuntai supplied logoSHUNTAIRUBBER & PLASTIC FOAMING MATERIALS

solution · source-backed review

EVA/PE: Low-Formamide and Low-Odour Evaluation

Evaluate blowing-agent selection, functional additives, processing history and finished-product testing as one system.

Discuss this requirement
EVA/PE: Low-Formamide and Low-Odour Evaluation — supplied material
Supplied SY-1 sample photograph. Product sample only; not a customer application or result.
Approach
Material and process together
Validation
Controlled comparison
Boundary
No guaranteed outcome

A foam has more than a density target

The supplied solution covers EVA footwear, yoga and floor mats, children’s foam, PE/EVA sheets and rolls, packaging and cushioning. It treats expansion, cost, formamide, odour, cells, shrinkage and long-term dimensional stability as related targets.

Symptoms that need to be separated

  • Elevated formamide test results.
  • Odour directly after demoulding or returning after sealed packing.
  • Insufficient expansion or increased shrinkage after changing to a lower-temperature agent.
  • Coarse, merged or broken cells and unstable skins.
  • Density/hardness lost when AC dosage is reduced.
  • Batch variation in density, dimensions or odour.

Material, process and acceptance information

Record resin grade, AC model, crosslinking system, actual material temperature, moulding time, thickness and post-ageing. Define the intended market and the specified finished-product tests; odour, VOC and formamide are different evaluation items.

A single substitution may not solve the system

Release before the material develops gas retention can lose gas; late release can leave insufficient foam, residue or later swelling. Match gas release to melting, crosslinking and cooling, instead of treating a lower nominal decomposition temperature as a complete solution.

Three routes from the supplied solution

RouteCandidate actions
Retain the mature AC systemReview SA grade against the temperature window; assess SY-1 and SQ-1/SQ-2 as appropriate; review temperature, time and ageing.
Medium/low-temperature modified routeAssess SPE or other modified AC against actual temperature, residence time, crosslinker and activation.
AC reduction with an endothermic componentEvaluate NC to adjust release behaviour; determine any additional SY-1/deodoriser need from actual finished-product tests.

A compound route is not simple addition of ingredients. Components have different decomposition windows, gas types and rates; rebuild the formulation/process window through trials.

Define the effect you intend to measure

Odour reduction does not establish a formamide value, and either result alone does not establish VOC compliance. Select a route from the actual material, processing history and product requirement, not from an unconditional “zero” claim.

Four comparisons and traceable samples

  1. A · Baseline. Current compound, agent, dose and process, with the current result recorded.
  2. B · Direct replacement. Change the candidate agent while holding other conditions steady.
  3. C · Process optimisation. Evaluate permitted adjustments to actual temperature, time, speed, pressure and cooling.
  4. D · Alternative. Compare a second candidate or a reviewed compound route.

For each group record model, batch, dose, mixing order, equipment settings, actual material temperature, pressure, speed, residence time, mould/die, cooling and sample time.

For this application, also record compound batch, mixing, actual temperature, moulding time, thickness, cooling and ageing before sampling.

Compare more than an initial odour impression

  • Apparent density, expansion and part weight.
  • Cell size/distribution, merging and breakage.
  • Shrinkage and dimensions at 24 hours, 7 days and 28 days where relevant.
  • Hardness, tensile, tear and compression properties.
  • Whiteness, colour and yellowing.
  • Odour after 24 hours, 7 days and 28 days, plus separately specified formamide, VOC and other restricted-substance tests.

Pending confirmation No numerical formamide reduction, odour grade, validated formulation or original finished-product report is supplied for this solution.

Advice remains subject to the customer’s validation

A successful small trial does not establish stable production performance. Recheck batches, actual equipment temperatures, mixing and feeding, speed, pressure, residence time, mould/die condition, cooling and ageing during the production trial.

Technical advice does not replace the customer’s formulation responsibility, production verification, finished-product testing or target-market requirements.

Describe the odour or chemical requirement

Provide the material and grade, process and thermal history, current formulation, issue, target tests/methods, destination market and acceptable density, cells, mechanics and dimensions.

Discuss an EVA/PE evaluation