Workers at the Pot Noodle factory in Crumlin have gone on strike over a pension dispute with employers Unilever.
Members of the Unite union are taking part in the industrial action on Thursday in a series of 11 days of strike action at sites across the country.
The company wants to end its final salary scheme. Unite, Usdaw and GMB unions say the move will cut retirement income for staff by up to 40%.
Unilever has maintained that almost 90% of affected staff will keep 80% or more of their pension and that changes needed to be made because of rising costs of its final-salary scheme.
In a statement, Unilever said: “The reality is that the union representatives had multiple opportunities to help shape the greatly improved final outcome of consultation we reached in October, but unfortunately they decided to walk away from talks.
“Making these changes was a tough but necessary choice which reflects the realities of rising life expectancy and increased market volatility.”
Around 200 people are employed at Crumlin, producing 155 million Pot Noodles a year.