[0001] This invention relates to apparatus for wetting filaments.
[0002] It is known that some composite bodies comprise filaments, such as glass fibres,
encased in a medium such as cured epoxy resin. Where the formation of such bodies
is on a mass production basis and is repetitive, it is advantageous to include apparatus
in the production line which will perform the necessary operations. One such operation
is wetting a continuous filament and presenting the wetted filament for application
to the body being formed.
[0003] According to the present invention, apparatus for treating a continuous filament
with a wetting medium comprises a bath for the medium, a roller guide assembly having
a plurality of staggered upper and lower rollers arranged at one side of the bath,
a filter assembly arranged at the opposite side of the bath, and an intervening partition
plate between the assemblies whereby drawing a fibre through the bath and the roller
guide assembly induces a current flow to cause medium to circulate about the partition
and through the filter assembly.
[0004] The invention will be described further, by way of example, with reference to the
accompanying drawings; in which:-
Figure 1 is a side sectional view of an embodiment of the invention; and
Figure 2 is a plan view of Figure 1.
[0005] In the drawings, a bath 1 contains a wetting medium 2, such as a -liquid epoxy resin,
up to a level 4 in the bath 1. The bath 1 is supportect on a base plate 5 by bolts
6, the base plate 5 also carrying a covert for an electrical heater 7' located beneath
the bath 1. The heater 7' serves to maintain the medium 2 in a liquid state. Current
for the heater 7' is supplied to terminals 8' by a cable (not shown) which enters
the cover 7 through a cable port 8. A tray 9 surrounds the bath 1 and is secured to
the base plate 5 by connectors 10, the tray serving to collect any wetting medium
which escapes from the bath 1.
[0006] A continuous strand or filament 3, for example a filament of glass fibre, is guided
through the bath by a roller guide assembly 11. The guide assembly 11 is removably
disposed in the bath 1 at one side thereof as can be seen from Figure 2. The guide
assembly 11 comprises a top plate 12 with handles 13 and a staggered arrangement of
alternate upper and lower rollers 14. The upper rollers of the assembly are supported
from the plate 12. The lower rollers of the assembly are journalled on a partition
plate 15. The partition plate 15, which is provided with a lifting eye 15' for removal
during bath cleaning operations, extends to the bottom of the bath and serves to separate
the roller guide assembly 11 from a filter assembly 16 which is situated in the bath
at the opposite side of the plate 15 to the roller assembly 11.
[0007] The plate 12 which carries the upper rollers is retained in an operating position
by a clamp 17 which resiliently urges the upper rollers on to the lower rollers of
the assembly 11, thereby providing strand tensioning.
[0008] The filter assembly 16 comprises a comb 19 one end of which lies on the bottom of
the bath 1 and the other end of which is suspended from a support 20 which spans across
the top of bath 1 between one side wall of the bath and the top of partition plate
15. The comb 19 is immersed in the depth of the medium 2 as can be seen from Figure
1. A handle 21 is provided for removal of the comb 19 for cleaning.
[0009] In operation, the fibre strand 3 enters the bath 1 at the right hand side, referring
to the drawings, and is threaded through the guide assembly 11 in an under/over/under
manner, leaving at the left hand side of the bath 1. The drawing of the strand through
the upper and lower rollers 14 induces a relatively weak pumping action which is sufficient
to create a current in the medium to cause flow between the guide assembly and the
filter assembly about the partition plate 15 and as indicated by the arrows X, Y in
Figure 2, it being understood that the partition plate 15 does not extend as far as
the two end walls of the bath, see Figure 1. The induced flow is sufficient to cause
the wetting medium 2 to pass through the comb 19 which traps any solid foreign matter
in the wetting medium. The comb 19 can be removed periodically from the bath for cleaning.
The fibre strand 3 is impregnated or coated (or both) with wetting medium 2 during
its passage through the bath 1.
1. An apparatus for treating a filament with a wetting medium characterised by a bath
(1) for the wetting medium, a roller guide assembly (11) having a plurality of staggered
upper and lower rollers (14) arranged at one side of the bath, a filter assembly (16)
arranged at the opposite side of the bath, an intervening partition plate (15) between
the assemblies (11, 16) whereby drawing a fibre (3) through the bath and the roller
guide assembly induces a current flow in the medium to cause medium to circulate about
the partition and through the filter assembly.
2. An apparatus according to claim 1 in which the filter assembly (16) is removable.
