Do you actually not know the difference between free trade and capitalism? Capitalism is when investors own the means of production in order to extract profit from a disparity between price and cost (including labor wages). There are plenty of free trade models which don't utilize capitalism, they are not the same thing.

Grog (the worker) owned his own axe (means of production) and traded the wood he gathered for shiny shells (free trade). Capitalism would be if Bunga (capitalist) owned the axe and then traded the wood Grog gathered himself, giving Grog some shells while keeping the rest (profit).