is 20 to 30 lower than the untreated chip the preferred chip structure can be further characterized by british disintegrator test where less than about 40 of the disintegrated chips are greater than 1 65 mm in size and preferably less than 20 of the disintegrated chips are greater than 1 65 mm in size chips destructured as described above can be pulped using conventional or known chemical pulping processes in kraft or soda digestion operations the chips are digested with a liquor consisting of sodium hydroxide alone or in combination with sodium sulfide in acid sulphite operations the cooking liquor is a mixture of sulphurous acid and sodium magnesium or calcium sulfite alkaline sulfite cooking is preformed with a cooking liquoor containing sodium sulfite and sodium hydroxide in bisulphite operations the cooking liquor is a mixture of sulphurous acid and sodium bisulfite anthraquinoine can be used in these processes to further improve the pulp pulping may be carried out in a batch or continuous operation typical pulping conditions are temperatures in excess of 130 u00b0 c and pressure of 30 to 80 psig chips destructured in accordance with the present invention are particularly desirable for use in vapor phase cooking as indicated previously it is not desirable to reduce kapp below about 30 to 40 by cooking instead kappa should be reduced to about 50 and then the pulp should be delignified further under milder conditions as a corollary cooking conditions temperature and time are preferably limited such that the h factor does not exceed about 400.