Abstract: A system for heat sealing in conjunction a pair of plastic strips each of having a series of regularly spaced transverse pockets so that the pockets together form chambers separated by webs. The two pocketed strips to be joined are brought together and the strips heat sealed around the pockets to seal the chambers from one another while passing cooling fluid over the pockets so as to avoid distortion or collapse of the pockets.

Abstract: A flexible plastic cuvette belt comprises a series of open-topped chambers defining said cuvettes interconnected by webs. The chambers are generally rectangular in cross-section with their side faces having an approximately flat profile across their widths. The belt is used in conjunction with a photometric analysis station of the clinical analyzer which has a pair of spaced parallel plates which engage the cuvette side faces and render or keep them parallel. The forming press for use in the manufacture of such a cuvette belt is also disclosed.