Whanganui business Axiam Plastics has increased its staff from 90 last year to 140 this year, and taken on some of the workers laid off by Mars Petcare.
The growth has come from some new customers, but also from existing customers wanting more product, general manager Matthew Smith said.
"It's just they have all grown a little bit."
The factory operates six days a week, with three shifts per day.
Axiam Plastics makes plastic parts and components for other products. Some are assembled on-site, but most are sent away to New Zealand customers to assemble.