JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS 1. For liquids containing detergents, i.e., shampoo, Pliofilm or P.V.C. are acceptable as the inner ply of a lamination. Polythene has not proved reliable owing to a tendency to weaken and delaminate over a period. Saran film, whilst providing very good protection, is extremely difficult to seal satisfactorily in film form, and when applied as an emulsion does not give a sufficiently strong seal to hold other than very viscous products. 2. The problem of packing powders or granular products does not present the same problems as, broadly speaking, these products have to be protected from access to moisture, oxygen, etc., from the outside, and the components of the lamination are rarely in contact with liquid, but have to stand up to conditions of high humidity. For this class of product a wide range of materials is available in the form of laminations of paper, aluminium foil, Pliofilm, polythene, Saran, P.V.C., and vinyl films, so that it is possible to tailor a material to suit the most exacting requirements. 3. Preparations containing large proportions of water do not present quite the same problems, although loss of essential ingredients through plastic film is always a matter which requires checking in each individual case. What of the future ? How far will the use of flexible packaging material extend into the cosmetic field ? Already it is making its presence felt with the single facial tissue which is impregnated, and contained in a sealed pouch. This type of toilet preparation was first used on airlines but it has now a much wider market. Face packs in sachet form have a steady sale, and combination packs of hair tints and shampoo have certainly arrived. The "one shot" pack although perhaps not economical from the con- sumers' point of view, is becoming more and more popular. Hand cream, face cream, or hair cream, packed in this way are certainly possibilities for the holiday trade or for travelling. On the Continent, catch-covers con- taining sachets of different sorts of beauty preparations are sold so that women can try small portions inexpensively and thus determine which they like best. This type of pack can also be used as the "give away" to introduce a new line. In all, although unlikely to greatly affect the field of beauty preparations which are catered for adequately by a wide variety of jars, bottles, tubes, etc., flexible packaging must surely play a much larger part in the market of cosmetics and toilet preparations in the future. (Received: 17th May 1961) REFERENCE •Christie, H.W. Modern Packaging. 34 213 (April) (1961).

FLEXIBLE PACKS 51 DISCUSSION MR. R. F. L. THOMAS: You have covered the relationship of jaw or platen pressures and temperatures to material type. You have not men- tioned, however, the possibility of temperature effects on the laminant (rather than the bonding laminate) and I should like to know your comments on the temperature stabfiity of the types employed. THE LECTURER: This is an extremely difficult question. In use there is a tendency for the heat to affect the laminate. We can very satisfactorily anchor foil to paper, and subsequently anchor paper to plastic material. With two laminates, we can test these individually for strength, ageing, etc. If the wrong laminant is used it tends to embrittle after applying heat, and then delamination of the foil and paper occurs. When anchoring paper to plastic, heat tends to force a certain amount of the laminate into the paper and not leave sufficient behind to hold the film the characteristics of the laminant can also be altered by the effect of heat, thus weakening the bond. This is a very complicated matter and we are working on it at the moment. Nevertheless, the laminants used at present are much better than those used in previous years. This brings me to another point. Cellulose acetate is plasticised. In order to get flexibility and the characteristics one requires, certain plasti- cisers have to be used. Cellulose acetate is often used in food packing, and the question of toxicity then arises. At too high a temperature (10-20 ø) the plasticiser volatilises, and the character of the material changes, becoming embrittled. Heat, therefore, affects not only the laminant, but also other ingredients. In foil, if there is excess moisture, etc., in the laminate, the platens will turn it into steam and this will blow the laminate apart. Immediately the platens come apart the lamination tends to separate. This trouble is ex- tremely difficult to spot, but it does happen. DR. H. W. HIBBOT•: (1) Have you any views on maximum amounts of moisture, and methods of determining moisture in paper, for this purpose ? (2) Plioffim deteriorates in alkaline conditions, particularly in the presence of light, and I wonder if development of metalized sachets and opaque finish sachets is a rather elegant method of getting over the shortcomings of Pliofilm ? THE LECTURER (1): This is a matter of compromise. When moisture is reduced below the order of 4-5% the paper becomes embritt!ed and there is loss of strength. With more than 7-8% moisture within the paper, there, is a tendency towards "blowing".