[0001] The invention relates to firelighters.
[0002] A well known firelighter in general domestic use is the so-called white firelighter
which comprises a solid block and which is based on a kerosene/urea- formaldehyde
resin system. It was developed during the 1950's out of wartime work carried out at
the Fuel Research Station.
[0003] The firelighter is white because this colour is produced in cross-linking of the
resin to afford a solid matrix. The white firelighter has been accorded certain advantages
such as a clean, aesthetically pleasing appearance, with low odour and good tactile
properties. The material is easily cut and it provides a block which is readily visible
for ignition among the darker fuel used in a domestic fireplace such as coal or coke.
[0004] The known white firelighter does however present some disadvantages. Its manufacture
depends on the emulsification of kerosene into the resin base and subsequent hardening
of the resin. Poor emulsification and/or poor hardening can lead .to products which
exude kerosene, or water, or both. These effects, in turn, can lead to such problems
as staining of packs, poor appearance, poor smell, condensation within film wrappings,
difficulty of ignition, poor candle-like flames and general inferior quality. Such
problems may be exacerbated by attempts to conserve or reduce the kerosene contents
of firelighters, a desirable requirement in view of the present problems with oil
supplies.
[0005] We have now made the surprising discovery that it is possible to produce a white
firelighter which retains the advantages of good appearance, low odour, ease of cutting,
and ready visibility among dark domestic fuels, and which also removes or reduces
the disadvantages associated with emulsification and hardening.
[0006] According to the invention, a method of manufacturing a firelighter comprises the
combining of kerosene, a binder in the form of a soap system, and perlite, a volcanic
glass.
[0007] Perlite is a white material which takes up some of the liquids in the composition.
It fills and thickens the composition and helps to promote long, controlled but effective
burning. Perlite is also a low density material which helps to lighten the product.
This may be advantageous in transporting the product in bulk and certainly to the
housewife carrying the product home.
[0008] It has been found that a firelighter according to the invention is relatively easy
to light, burns well, and may afford significant kerosene economies.
[0009] Preferably the soap system is formed by reacting stearine with caustic soda.
[0010] Preferably kerosene and stearine are first mixed together, for example in a steam
jacketed vessel at 70° to 75
0C and are then mixed with caustic-soda at a similar temperature, for example in a
further steam jacketed vessel.
[0011] Preferably the perlite is added subsequently.
[0012] The firelighter may contain from 35 to 80% (e.g. 50 to 70%) kerosene by weight.
[0013] The firelighter may contain from 1 to 10% (e.g. 5 to 8%) stearine by weight.
[0014] The firelighter may contain from 1 to 5% (e.g. 1 to 3%) solid caustic soda by weight.
[0015] The firelighter may contain from 5 to 15% (e.g. 6 to 10%) water by weight.
[0016] The firelighter may contain from 1 to 25% (e.g. 1 to 20% or 2, to 15%) perlite by
weight.
[0017] As an alternative to caustic soda, sodium silicate may be used. The firelighter may
contain from 2 to 10% (e.g. 4 to 7%) by weight of a sodium silicate solution containing
25 to 55% total solids.
[0018] In order to vary the cost, economy of materials, performance, appearance, or other
properties, the firelighter may include one or more of the following additives: liquid
fuels or waxy materials; solids which have an intrinsic fuel value; solids which have
no fuel value.but which may act as modifiers of appearance, consistency, burning properties,
or which may function solely as fillers.
[0019] Additives may include whiting (Snowcal), Kaolin, Kiesselguhr, mica, calcite, vermiculite,
fillite, flyash, pumice, talc, Bentonite, alumina, sodium carboxymethyl cellulose
and related compounds, starch, sodium carbonate, sodium bicarbonate, and foamed-or
expanded plastics.
[0020] The invention includes a firelighter manufactured by the method according to the
invention.
[0021] By way of example, specific embodiments of the invention will now be described, with
reference to the accompanying drawings, in which:-
Figure 1 is a diagrammatic view of an apparatus for carrying out a first embodiment
of the invention; and
Figure 2 is a diagrammatic view of an apparatus for carrying out an alternative embodiment
of method according to the invention.
[0022] Referring first to Figure 1, kerosene and stearine are fed to a first steam jacketed
vessel 10 via pipes 11 and 12 respectively. They are mixed in this vessel by means
of a stirrer 13 and the mixture overflows via pipe 14 to the bottom of a second steam
jacketed vessel 15. Caustic soda and water are fed into the vessel 15 through pipes
16 and 17 respectively and mixing again takes place using a stirrer 18. In this vessel
a soap forms into which the kerosene is bound. The hot mixture overflows from the
steam jacketed vessel 15 through a pipe 19 and is pumped by a pump 20 to a mixing
device 21. The mixing device comprises a downwardly directed tube containing paddles
22 driven by a motor 23. Fillers are fed to the mixing device 21 through a screw feed
device 24. The fillers are mixed into the hot composition as the composition travels
down the tube 21 and the final composition passes into a mould device 25 where the
composition cools and sets.
[0023] In the alternative embodiment shown in Figure 2, the caustic soda and water are first
mixed together in an unheated vessel 26 before they join the kerosene and stearine
mixture in the steam jacketed vessel 18. The output.from the pump 20 leads to a two-way
valve 27.so that the hot mixture can either be recycled to the vessel 18 or can be
; pumped via pipe 28 to the inlet of a wide throat monopump 29. The fillers 31 are
fed from a hopper 30 to the pump 29 by a moving belt conveyor 32 which forms the base
of the hopper 30. The hot composition and the fillers are mixed together by the pump
29 and are fed via pipe 33 to the mould device 25 for cooling and setting.
[0024] There will now be described six examples of compositions which may be manufactured
using the above described embodiments.
EXAMPLE 1
[0025] The following composition was used:

[0026] The kerosene and stearine were first mixed together at a temperature of from 70°
to 75°C. This mixture was then reacted with the caustic soda and water at the same
temperature. The perlite was then subsequently mixed in and the composition was allowed
to set.
[0027] The set composition was cut into rectangular blocks weighing'25 grams and it was
found that one 25 gram block burnt for 19 minutes and 44 seconds.
[0028] The finished composition set to give a non-gritty solid which had dry surfaces even
when cut.
EXAMPLE 2
[0029] The following composition was used:-

[0030] The kerosene, stearine, caustic soda and water were mixed as before. The snowcal
was then added and mixed in, the perlite was then added and the mixture was allowed
to set. It was cut into blocks of 25 grams each and one block was found to burn for
26 minutes and 45 seconds.
EXAMPLE 3
[0031] While Example 1 and Example 2 were produced by a batch process, the following Example
was produced by a continuous process, the proportions of the ingredients being given
as a percentage of the total mixture by weight.

[0032] The final mixture was moulded by a continuous process into blocks, each weighing
29 grams in weight. It was found that a 29 gram block burned for 22 minutes and 41
seconds.
[0033] The invention is not restricted to the details of the foregoing embodiments and examples.
1. A method of manufacturing a firelighter characterised by the steps of combining
kerosene, a binder in the form of a soap system, and perlite, a volcanic glass.
2. A method as claimed in Claim 1, in which the soap system is formed by reacting
stearine with caustic soda.
3. A method as claimed in Claim 2, in which the kerosene and stearine are first mixed
together at 70 to 75° and are then mixed with caustic soda at a similar temperature.
4. A method as claimed in claim 3, in which the perlite is added subsequently.
5. A method as claimed in any one of the preceding claims, in which the firelighter
contains from 35 to 80% kerosene by weight.
6. A method as claimed in any one of the preceding claims, in which the firelighter
contains from 1 to 10% stearine by weight.
7. A method as claimed in any one of the preceding claims, in which the firelighter
contains from 1 to 5% solid caustic soda by weight..
8. A method as claimed in any one of the preceding claims, in which the firelighter
contains from 5 to 15% water by weight.
9. A method as claimed in any one of the preceding claims, in which the firelighter
contains 1 to 25% perlite by weight.
10. A method as claimed in Claim 9, in which the firelighter contains 1 to 20% perlite
by weight.
11. A method as claimed in claim 1, in which the soap system is formed by reacting
stearine with sodium silicate.
12. A method as claimed in claim 11, in which the firelighter contains from 2 to 10%
by weight of a sodium silicate solution containing 25 to 55% total solids.
13. A firelighter when manufactured by the method claimed in any one of the preceding
claims.