The lockout took effect at 9 p.m. on Sunday, and the employers' association is asking federal Labour Minister Steven MacKinnon to intervene.
Mattr, through its subsidiary, has entered into a definitive agreement to acquire all of the outstanding shares of AmerCable from Nexans USA Inc.
Through the partnership, NEO aims to transition from pilot-scale production to large-scale commercial manufacturing of its silicon anodes.
Canada's manufacturing sector faces the biggest risk should Trump push forward on imposing broad tariffs, said Canadian Manufacturers and Exporters president and CEO Dennis Darby.