Success came quickly, and soon the family expanded their equipment and built a factory next to their home on the Tveiten farm. Through dark times like WWII, when yarn was scarce and every item had to be carefully rationed to brighter days as Europe recovered, the Tveitens never stopped knitting.

Shortly after the war, Ola's sons, Åsmund and Odd Tveiten, took over the business. They built a new factory three kilometres from the farm, down by the fjord in the village of Hosanger. In those days, most traffic on Osterøy went by boat. By the fjord, goods could be shipped in and out with ease, and customers could come to visit. The Norlender factory still stands there today.

By the 1980s, low-cost imports had flooded the Scandinavian market, and the company had to fight to survive. In the winter of 1989, the third generation took over: Odd Tveiten's children Gyda, Astrid, Ola and Magnus, together with Gyda's husband, Alwyn Lewis. They replaced the factory's circular knitting machines with heavier flat-knitting machines, switched from cotton to wool, and started making sweaters and cardigans. With the new machines came a new name: Norlender. The years were hard. Many Norwegian textile factories closed in the same period. The Tveiten siblings kept theirs running.