In the fourth quarter of 2018, Lydall's
net sales increased by $31.9 million, or 17.9%, to $209.9 million, compared to $178 million in the fourth quarter of 2017 as a result of the acquisition of Interface Performance Materials, which increased Performance Materials ("PM") segment net sales by $33.9 million. Organic sales growth was 4.2% in the PM segment driven primarily from improved sales of filtration products. The Technical Nonwovens ("TNW") segment reported organic sales decline of 4.7% due to lower demand and timing of orders of filtration products in China and reduced sales of advanced materials products. The Thermal Acoustical Solutions ("TAS") segment reported a marginal reduction in organic sales as reduced parts sales in North America and China were partially offset by increased parts sales in Europe.
For the full year 2018, the company reported net sales of $785.9 million in 2018, including $48.9 million from acquisitions, compared to $698.4 million in 2017. Organic sales growth was 2.2%, with modest growth in all segments. Gross margin was 19.4% in 2018 compared to 23.4% in 2017.