The reason why the chinese exports to argentina are of lower quality than those to the united states is the following:
Chinese exports to the united states were for years paid in US Bonds.
The Federal Reserve can print these out of thin air with near 0 cost and receive the goods.
The volume of purchase from the US are huge anfd this gives the opportunity of better prices and goods made specially for american corporations Example Walmart or Nike
Argentina has to pay in dollars for the imports, which means that argentina has to work for the moneypaid, argentina does not have the printing machine to give the chinese worthless US Bonds.
The argentine market is small so it cant "hire" complete factories for especial productions which tend to be of higher quality.
I hope this clarifies in general terms the reasons for the difference in quality.