Paper manufacture at Kaipola

The first phase of the Kaipola mill was completed in the mid-1950s.After the Myllykoski mills separated from United Paper Mills Ltd in 1952, the company was left without a newspaper mill. It was decided to build a new substitute mill at Kaipola in Jämsä. The first papermaking machines were ordered from the United States and England. In addition, an old machine was brought from Simpele for use as a wrapping and tube paper machine.

Kaipola's PK 1 started up in September 1954. For a long time, there were difficulties with the working of the machine and the paper quality did not reach the expected standard. Production improved when the manufacturer of the machine delivered a new headbox in 1956. In the same year, PK 2 also started up, making rolled newsprint. A second supercalender was ordered for the machine in 1959. About 2/3 of Kaipola paper was sold to France, England and West Germany. As demand was high, it was decided to buy a new papermaking machine.

The American-made PK 4 started up at Kaipola in March 1961. The machine represented the highest technology of its time.The machine was ordered from the world's most famous machine manufacturer, Beloit of the United States. At the same time a second machine was reserved. PK 4 started up in March 1961. At the beginning of the decade, improvements to the old machines were also made. PK 5, equipped with two machine calenders, became operational in spring 1964. Kaipola paper production had risen to over 300,000 tonnes a year. The mill produced newsprint and magazine paper. About half of the production was rolled SC paper.

Rolled speciality paper

Kaipola aimed to produce speciality papers, to which average newsprint prices would not apply. Customers were found independently, bypassing the sales organisation of Finnpap, the association of Finnish paper mills. One of the major customers was English Associated Newspapers Ltd which used SC paper to print its newspapers and magazines. In the 1970s Kaipola became the flagship of United, also in financial terms.

Kaipola mills had experimented with the use of talcum instead of kaolin as the filler material of paper. The results were so positive that the change to the sole use of home-produced talcum in print paper production was made in 1969. Product development of print paper continued under the leadership of Per-Erik Ohls, the mill director. The mill specialised in lightweight printing paper; when the output tonnage could not be increased, due to a shortage of pulp, a larger area was made from the same amount of pulp.

In May 1975 Kaipola was the first mill in the world to make 45 gsm lightweight printing paper totally without cellulose. From the left: Per-Erik Ohls, Ahti Syrjänen, Pertti Ruusu, Reima Kortelainen and Niilo Hakkarainen.The lighter paper also pleased customers, because it reduced transport and distribution costs. The first customer to change to the lighter newsprint was Aamulehti. It was soon followed by The Times and Daily Mail. The development work at Kaipola on refined mechanical pulp had led to good results, and in May 1974  45-gsm lightweight printing paper was first made totally without cellulose.

Due to the recession the Kaipola machines were also standing idle on occasions in 1975. Improvements were made to PK 1 at the end of the 1970s, but finally, in 1982, the machine stopped as it was unprofitable. The mill's other two 1950s machines, PK 2 and PK 3, were stopped in 1989 and 1988. PK 4 and PK 5 stayed in use. Kaipola had to wait for a new papermaking machine until 1985, when it was decided to build a machine complete with a thermo-mechanical pulper for the manufacture of coated magazine paper.