44 liquid foam although there is plenty of work done on the characterisation of solid foams from natural rubber latex. Therefore, the current paper explores the usage of a foam analyser to obtain information pertaining to the liquid foam from natural rubber latex. METHODOLOGY Natural rubber latex was obtained from a local supplier and the latex was foamed using a foam analyser (FOAMSPIN, TECLIS Sarl, France) without the addition of any chemicals. The instrument (Figure 3) is equipped with a set of rotating blades, which produces foam under INTRODUCTION Since the discovery of vulcanisation 1 , natural rubber latex (NRL) has been used to produce a variety of regular goods. One very interesting product is latex foam rubber which saw development in the late 1920’s 2 . Eventually the industry bloomed and today, latex foams are made to cater for a wide range of products, such as mattresses, pillows, cushions and automobile seatings 3 . In general, latex foam rubber products are made by incorporating air into the latex and whipping it before it is gelled using a delayed action gelling agent and dried in the oven 4 . Unlike foam from dry rubber which has a closed cell structure, foam from latex has an open cell structure, in other words, they are interconnected (Figure 1) 5 . One key component responsible in the foaming of NRL is the surface active ingredient which stabilises the latex particles against coagulation during whipping, while promoting and stabilising the foam produced. Surface active ingredients, commonly known as surfactants, are molecules comprising of two components, a hydrophilic (affinity to water) component and a hydrophobic (affinity to oil) component 6,7 . Surfactant molecules adsorb onto the interface of two systems and reduce its interfacial tension (Figure 2). In the case of a gas- liquid system, the surfactant will facilitate the dispersion of gas and reduce the size of bubbles, which changes the velocity and regime of bubble rise 8 . In order to produce a good latex foam, information on the liquid foam formation and stability, foam collapse, liquid drainage and foam structure are important. However, not much literature is available on natural rubber latex Manroshan Singh MRB Rubber Technology Developments Characterisation of Liquid Foam from Natural Rubber Latex This paper describes characterisation of liquid foam obtained from mechanical stirring of natural rubber latex. Subsequent decay in the foam was tracked using a foam analyser. Important information such as morphology of the liquid foam, number of bubbles, bubble polydispersity and area occupied can be obtained for further understanding and design of new foam products from natural rubber latex. Figure 1. Latex foam rubber structure obtained using a Carl Zeiss microscope showing the interconnected cells.