Johnson Service Group said that its results for the first half of 2015 would be robust and full year results were likely to top expectations.In a brief announcement, the textile-related services company said that the integration of its recent acquisition, the London Linen business, was trading in line with expectations.Following the purchase, net debt at the end of the first half was slightly lower-than-expected at £73m.Results for the six months to 30 June will be published on 2 September.As of 9:30 BST, Johnson Service Group was trading 3.8% lower at 90p.