In 1949 I got a job with a company named Tenaplas Ltd located in Upper Basildon,Berkshire where I was involved in the development of large bore LD polyethylene tubing.At that time the development of extrusion machines for thermoplastics was in its infancy and most companies used modified rubber processing machines.We used for experiments on extruding up to 7in.dia tube a modified Iddon 4in.rubber machine with a 12:1 ld ratio screw and a crude carriage type haul off.
In 1950,Ken Pepper the general manager managed to get a contract for the production of 5 miles of 6in.ID polythene tube for the Home Office for use in emergency water supply in the event of a nuclear attack on the UK.
We had no machinery capable of producing this amount to tube and nothing suitable was for sale.This is where the Francis Shaw equipment comes into the picture.We purchased a new Francis Shaw 31/2in.rubber extruded and modified it with a 15:1ratio screw and a Schrage type variable speed electric motor.We also constructed. 60ft.rail type haul off with manual tube cutting saw.This equipment was constructed in seven months and continued in production until 1954 or5.All told this equipment together with another machine produced over 120 miles of this tube.
