Unite the Union said workers at the facility were called to a meeting on 20 September and told that the site would be closed.
The main catalyst for the decision was the firm’s loss of a long-standing contract to produce paper-based betting products for bookmaker William Hill, which Unite said no longer required Essentra’s services “as the betting industry has moved towards new technology”.
Unite regional officer Andy McFarlane said: “This is a devastating blow for the workers at the site and also for the people of Kilmarnock. These jobs were highly skilled and were carried out by a dedicated workforce.
“Not only has this announcement left workers shattered, it is yet another blow to the wider community of East Ayrshire and a nail in the coffin of the town’s manufacturing base.
“This closure is an example of negative outcomes of the move towards technological change taking place across the industrial landscape.
“It is clear that while we must not shy away from automation, this must be done in a way that protects jobs and allows workers to share in the benefits of technological advances and must be done through collective bargaining with trade unions. The failure of Essentra to plan for the future has led to these job losses.”
Formerly known as Ritchie (UK), the site was previously a wholly-owned subsidiary of Clondalkin Group’s Specialist Packaging Division, which was acquired by Essentra in 2014 in a $455m (£349m) deal, its biggest acquisition to date at that time.
In a statement published in the Daily Record, an Essentra spokeswoman said it was “with regret” that the company has had to announce proposals to close the site following “the withdrawal of all orders by a long-standing and very significant customer”.
“This means that we are now entering a formal consultation period of at least 30 days which, if our proposals are confirmed, would result in around 50 redundancies and the site being closed by the end of 2018,” she added.
“We recognise that this is a disappointing decision and it is not one that we have made lightly.
“We take our responsibilities as a local employer extremely seriously and are fully committed to finding ways to provide our employees with appropriate support both during and post the consultation period should the proposals be confirmed.”
In its results for the half-year period ended 30 June 2018, Essentra posted revenue of £513.1m, down 1.8% year-on-year, though its pre-tax profit was up by 7% to £20.8m. Its packaging division accounted for £170.2m of sales in the period, down 7.8% year-on-year.
Last year around 150 jobs were lost when Essentra closed its loss-making Newport folding cartons site.