Modulus of Latex Products

Manufacturer: We are manufacturers of latex products. One of our customers requested that our products be harder and softer but without changing our curative formulations. How shall we proceed?

John Woon (Senior Latex Consultant): Technically you are talking about the "modulus" of the rubber which depends on the degree of cross-linking and cure state. The higher the modulus the harder the rubber. And the reverse is true.

Your customer asked for higher and lower modulus probably because they are concerned about the processability of the latex compounds if the curatives are changed.

I suggest you try adding MMA-grafted NR latex (or some synthetic latices) for higher modulus while adding plasticizer (e.g. mineral oil) for lower modulus.