In 1912 the firm converted to a Private Limited Company. Expansion of manufacturing facilities and trading was very marked both before and after the first World war, during which the Company played its part in the production of war materials and hospital supplies.
In 1923 Howard Franklin's eldest son, Burke, entered the business, followed in 1928 by his brother Patrick.
After the depression years of 1929-32, the Company extended its manufacturing capacity by acquiring additional factory premises in Slough.
In 1935 the company exhibited at the British Industries Fair at Olympia.
Harold Franklin, director and works manger, died in 1937.
In 1939 Paul, son of Frederick Franklin, and Michael, youngest son of Howard Franklin, joined the Company. Paul was killed in Normandy in 1944.
During the second World War the Company played its part once again by the manufacture of essential hospital and other supplies for the forces. Experience during time of war was put to good use after the end of hostilities in an extensive programme of reconstruction and modernisation. In 1948 it employed over 500 people.
In 1949 the company again exhibited at the British Industries Fair at Olympia.
In 1968 the Company was acquired by G. D. Searle & Co of Chicago and passed out of the hands of the family. The Hackney factory was closed in the 1970s, like several others: http://www.brickfields.org.uk/text/late20c-work.html A newspaper report of 1973 headed "Hackney rubber factory fire" says "Management and staff were evacuated when a fierce blaze swept through and East End rubber manufacturers' today. More than 40 firemen fought to control the fire - the fourth in two months - which broke out on the first floor of J. G. Franklin and Sons in Colvestone Crescent, Hackney."