The bindings that are on his upper arms are made of carbonite, and If you watch carefully you should be able to catch The Ugnaughts remove the bindings on Han's hands before he is lowered

Hands are up in the air and spread apart. One of the most outstanding an exciting things (other than realizing there were new Star Wars figures at retail) about finding the final wave of Kenner action figures at Toys R Us was that they felt so much bigger than previous action figures. Han Solo (In Carbonite Chamber) is one of them. When Han Solo is being put into carbon freeze (The Empire StrikesД«ack), his hands are cuffed. There were some large than life action figures released in THE POWER OF THE FORCE line. LEGO STAR WARS Han Solo In Carbonite Chamber Figure + Rare Stand - 752430 - New - 7.25. Interestingly, both the script and the official novelisation disagree, stating that he was firmly bound before being placed into the chamber.ДЄs to the bindings on his upper arms, those were already made of carbonite and hence melted away when Leia unfroze him, according to Steve Sansweet, former Head of Content/Head of Fan Relations for Lucasfilm. Which you can see in this scene just before Han is placed into the carbonite chamber. Two Ugnaughts approached Han, removed the manacles from his wrists,

The film's junior novel indicates that the Ugnaught guards removed them: So Han is standing there chained up, about to go down into the carbonite chamber, and Chewbacca's there, and Threepio and Artoo and Princess Leia.and.

Carbonite chamber