Abstract: Inorganic constituents of cigarette paper are identified and monitored by scanning a region of the infra red spectrum of the paper, computing first and second order derivatives of the scan, comparing the first and second order derivatives by a best fit comparison with reference spectral data, and computing concentrations in the paper of the identified inorganic constituents.

Abstract: Apparatus and method of forming a rod of tobacco from two types of tobacco in which the two types are stored in a hopper and separated therein by a partition, and deposited on an air pervious conveyor belt so that one type overlies the other type. Deposition of one type on the belt is periodically inhibited in favor of the other type by means of an air jet directed at the belt.

Abstract: A cylindrical filter element for a cigarette is wrapped in a ventilated tipping wrapper which is spaced from the filter element by a raised pattern of thermoplastic material printed on the inner surface of the wrapper. The pattern is designed to provide air channels communicating with the ventilations in the wrapper and leading to the mouth end of the filter. This enables the manufacturer to dispense with a separate spacing member which has hitherto been located between the filter and the tipping wrapper. The invention includes a method of making a filter element including such a raised pattern.

Abstract: Method of monitoring a line of adhesive deposited on a travelling paper web to check for accidental omission of adhesive wherein the adhesive has a distinguishing relative permittivity and is sensed by a capacitive proximity sensor. The web may be plugwrap material for cigarette filter rod, the adhesive being provided to anchor filter tow in position when the plugwrap is wrapped around it. The method avoids various disadvantages associated with other automatic monitoring devices such as optical devices and infra-red devices.