1. Polymer type
The polymer is the largest cost item in a recipe. From cheapest to most expensive, roughly: SBR and natural rubber (NR) → CR and EPDM → NBR and specialty polymers (HNBR, silicone, FKM). Different grades of the same polymer (ACN content in NBR, ENB content in EPDM) also move the price. Because polymer prices follow commodity and currency markets, quotes are kept short-dated.
2. Carbon black and filler loading
More carbon black means a smaller polymer share, which usually lowers the price per kg but changes hardness and strength. Highly reinforcing blacks (N330) cost more than semi-reinforcing ones (N660, N772). Mineral fillers (calcium carbonate, kaolin) reduce cost and limit performance. A "cheap compound" is usually a highly filled one; that is fine if the part still meets its specification, and not cheap at all if it does not.
3. Chemical package
Protective agents (antiozonants, antioxidants), accelerators and special adhesion or flame-retardant additives look small per kg but can be decisive in total. Long outdoor life, high-temperature ageing requirements or adhesion to cord fabric all enlarge the package.
4. Mixing stage and delivery form
Masterbatch (no cure system) and final compound differ in labour and second-stage cost. Slab is the cheapest delivery form; calendered sheet or strip adds calender labour and liner, but cuts preparation time and scrap at the moulder — total cost usually falls. Cut plates and special widths carry an extra processing charge.
5. Batch size and monthly volume
Small batches below mixer capacity raise unit cost; a regular monthly tonnage helps both raw-material buying and production planning, and shows in the price. Annual framework agreements are the best tool for price stability.
6. Quality level and test scope
Rheometer, Mooney, hardness and mechanical testing on every batch, batch traceability and a certificate of analysis are what an automotive-tier supplier provides. That infrastructure (laboratory, automation, IATF 16949 system) is built into the price; the return is lower scrap and rejection risk at the mould.
7. Customer recipe or producer recipe?
In toll compounding the customer's recipe is applied as is, so the price is largely raw material. With the producer's own formulation, a recipe that meets the same specification with more economical raw materials is often possible — which is why sharing the specification and asking for an alternative recipe is frequently the best route to price.
What to share for an accurate quote
- Polymer type or operating environment (temperature, fluid contact, outdoor)
- Shore A hardness and mechanical values (tensile, elongation, ageing)
- Delivery form: slab / sheet / strip, thickness and width
- Estimated monthly tonnage and delivery frequency
- Existing TDS, test report or sample if available
With these we quote the price per kg, a sample plan and lead time together. Use the form on the rubber compounds page or write to info@metekimkaucuk.com.
Frequently asked questions
How much does rubber compound cost per kg?
It depends on polymer type, recipe, delivery form and tonnage; at the same hardness an NR/SBR compound and an NBR compound can differ several-fold. We quote a firm price per kg against your specification and monthly volume.
Why do prices change so often?
Natural rubber, synthetic polymers and carbon black are priced in commodity markets in foreign currency, so quotes are short-dated and longer-term supply is handled by framework agreements.
Why is calendered compound more expensive?
Calender labour and liner are added; in return preparation labour and scrap at the moulder fall, so total cost usually goes down.
Are samples charged?
The sample and laboratory development process is planned per project; when you send your specification we quote the sample plan together with the price.