JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Corks are supplied in various shapes, the most popular types being tapers and parallels. A common modification made with parallel corks is to cut or shape a bevelled or rounded point. For certain bottling purposes, such as gin, corks are supplied with clean points or tips. This is done by 100 per cent hand sorting and notching out pores on points of corks, which minimises dust effect from corks, but is expensive. It might be said that the aristocrat of corks are those used for the bottling of champagne only the finest quality selected wood is used in the manufacture of these, and most are made of three Ol four pieces. In use it is common for champagne corks to be com- pressed to one-third of original volume when in bottle necks. For certain purposes corks are treated with hot or cold paraffin wax, and, on the Continent, lacquer. Paraffin wax acts as a lubricant also these treatments minimise dust effect from corks. A particular feature of modern cork closures is the popularity of the flange top that is put on, or is shaped as an integral part of cork. This can be seen in common use on wine, spirits and fruit juice bottles. Flange tops can be made of decorated wood, decorated metal, wax compound or plastic. It helps easy removal of closure from the bottle and also serves a decorative and descriptive purpose. The composition type of cork closure is usually of conventional cork shape and is made of granulated cork, binder and possibly plasticiser. This was used to some extent before the last war as a wide mouth type of closure this use, however, has been largely superceded by the use of screw caps. Another purpose for which composition cork plugs are used at present to a limited extent is the bottling of such materials as Vin Ordinaire on the Con- tinent. In this case, the corks are presumably manufactured by a cheap moulding process which enables the product to be sold at a highly competitive price. GLASS STOPPERS The quantity of ground glass stoppers used commercially appears to have diminished if this is not precisely true, it is a fact that the percentage of glass-stoppered bottles used has diminished. Two possible reasons for this are: Expense: every stopper has to be hand fitted by carborundum grinding to each individual bottle. Misuse: there are two major ways of misusing glass stoppers the first is to allow a stopper to lose its original bottle with the probable consequence of a leaky closure. As acids are often the concerned bottled matehals, this can be dangerous. The other is to use them without lubricant this can be harmless as far as a decanter of brandy is concerned, but the instances of jammed stoppers in bottles of

BOTTLE CLOSURES acid or alkali are frequent, and it is not unknown for efforts to remove obstinate stoppers to result in accidents. A little soft paraffin on glass stoppers, particularly those used commercially, will invariably prevent this trouble. RIGID COMPOUND SCREW STOPPERS WITH RUBBER WASHERS As a carbonated beverage and ammonia closure, these stoppers have been in common use in Britain for some years. A point of interest is that they are not used for beer or mineral water bottling in the United States. Generally speaking, re-use closures are not permitted for food products in that country. Although this type oi closure has been criticised as being possibly unhygienic for carbonated beverage bottling, one must take into consideration that it has been used satisfactorily by our bottling trade for some considerable time. Other types of closures may replace these stoppers in time, but at present it can be said that the annum quantity used is going up. Important points with the use of this type of closure are: 1. They should be thoroughly cleansed and sterilised before re-use. 2. Any that are contaminated with objectionable foreign matter such as kerosene should be scrapped. 3. Rubber rings should be renewed if there are any signs of deterioration. RUBBER PLUGS Use of these is on the whole restricted to laboratories and the bottling of a few chemicals, probably because of expense. They are mainly used for the bottling of alkaline solutions and certainly are preferable to normal corks for this purpose. Their shape is of conventional tapered corks. When referring to size, however, it is usual to refer to the number found embossed on all plugs. One type of plug that has found some favour in industry is that which is made of somewhat soft rubber and has lateral serrations which add to sealing efficiency. This type Mso has a built-on rubber cap that is fashioned to fit around bottle top. Another type of rubber plug that is used is that which is shaped to form bottle plug and primary cap liner it is used in the bottling of such materiMs as spirituous perfumes to prevent evaporation. POLYTHENE STOPPERS The use of polythene stoppers in industry appears to be gaining favour points in the advantage of their use are: 1. Polythene is inert to the acids and alkalis normMly encountered.