Image of Sainsbury's new laboratories at 115 Southwark Street: tensile strength test of packaging film

Photograph by Brian Shuel which is part of a set (SA/IMA/4/SO/40/1-32) showing staff working in Sainsbury's new laboratories at 115 Southwark Street, London which opened in 1968. Some of the photos from the set were used for an article in 'JS Journal' (staff magazine) February/March 1969 pages 18-21 (this specific frame however was not used).

The picture features one of the rooms in the packaging laboratory with temperature and humidity control. JS Journal explains that: "The test being carried out is to determine the tensile strength of a packaging film. A strip of the material has been clamped between an upper and lower grip. The crossbar is drawn down at a controlled speed towards the limit of tensile strength. A graph (on the left of the chemist) records the breaking and elongation point".