There is slow growing tension and tense personal drama in Sweat but it is also inconspicuously provocative.

Seven years ago, playwright Lynn Nottage started spending time in Reading, Pennsylvania, one of the poorest towns in America and wrote Sweat based on her experiences there.

Set among a group of factory workers, what you get is in many ways a classic drama of friendship, jealousy and tragedy born out of a moment of madness. 

But globalisation and immigration beat at the heart of this story as, when the workers' way of life is threatened by layoffs, they are pitted against each other and big business.

Job for life ideology

This is a community brought up on the idea that a factory job is a job for life, where the reward for decades of hard, physical work is a good pension.

It is also a community where union cards are the key to the lucrative factory jobs but they are like elusive golden tickets if you aren't local or the right sort of local.

Two families form the centre of the narrative. Cynthia (Clare Perkins) works at the factory and her son Chris (Osy Ikhile) works there too but has longer-term plans to go to college.

Cynthia works with her friend Tracey (Martha Plimpton) and Tracey's son Jason (Patrick Gibson) who is happy to have his factory job and his life mapped out.

Friendships challenged

Tensions in their friendship first appear when there is an opportunity to apply for a promotion - the first person to make it off the factory floor into a management position.