Bosses said revenues had also increased, rising by 13 per cent to £120m, with pre-tax profits higher at £48.9m.
In a report, the firm said group sales volumes stood at 1,584 tonnes, compared with 1,392 tonnes in the same six months in 2013.
Earlier this year, it revealed a strong January had given sales an early boost.
The firm's products are used in a number of sectors, including resins and coatings for aerospace equipment, and substitutes for metal in gears across the automotive sector.
It Invibio Biomaterial Solutions division also supplies specialist products for medical device makers.
Anita Frew, Victrex chairman, said: “We saw continued growth momentum during the first-half of 2014, principally reflecting a very strong second quarter.
“We enjoyed particularly strong performance in our core business, alongside a return to growth in Invibio.
“Our second-half has started well, with volume trends building on our first-half performance and we will continue to focus on driving growth.”