WIRE COATING TECHNIQUE
FIG3 shows a cross section through a wire coating apparatus according to an embodiment of the invention
FIG3 shows three temperature zones within the coating apparatus 100. Temperature Zone 1, TZ1, comprises the upper cylindrical section 101 of the injection channel 107. Temperature Zone 2, TZ2, comprises the lower cylindrical section 102 of the injection channel 107. Temperature Zone 3, TZ3, comprises the coating chamber 103. Each temperature zone has a different temperature profile. It should be noted that the shown locations of the temperature zones are approximate. The temperature zones indicate different regions within the apparatus in which at least some, and preferably most, of the coating material in the region is heated to within a temperature range associated with the temperature zone. The desired temperature ranges within each temperature zone will depend on the specific coating material being used.
cross-sectional view
103
coating chamber
100
coating apparatus
3
Temperature Zone
403
control system
105
wire
402
cooling chamber
102
lower cylindrical section
101
upper cylindrical section
108
coating nozzle
106
piston
401
oven
['1. A coating apparatus (100) comprising: a coating chamber (103) for applying a plastic coating material to a wire (105) passing through the coating chamber; an elongate injection channel (107) for receiving plastic coating material input to the coating apparatus at a first end (101) of the injection channel through an inlet portion (104), and supplying the received plastic coating material to the coating chamber that is arranged at a second end (102) of the injection channel, wherein the inlet portion intersects a side wall of the elongate injection channel, the side wall extending between the first end and the second end of the elongate injection channel, the injection channel comprising a first cylindrical section at the first end of the injection channel and a second cylindrical section at the second end of the injection channel, wherein the diameter of the first cylindrical section is greater than the second cylindrical section; a piston (106) that is moveable along the length of the first cylindrical section of the injection channel, the piston configured to pressurise the contents of the injection channel and coating chamber, the applied pressure causing the plastic coating material to flow down the injection channel; and a number of heating elements (109, 111) controllable to progressively raise the temperature of the plastic coating material as the coating material flows through the coating apparatus to achieve a desired viscosity of the plastic coating material within the coating chamber.', '11. A coating system comprising the coating apparatus of any preceding claim, an oven (401), a cooling chamber (402) and a control system (403); wherein: the coating apparatus is arranged to receive wire and to apply a layer of plastic coating material, to the received wire; the oven is arranged to receive wire output from the coating apparatus and to heat the wire to a temperature at which the applied plastic coating material sets; the cooling chamber is arranged to receive wire output from the oven and to cool the wire such that the wire output from the cooling chamber can be wound or fed back into the coating apparatus for a further layer of plastic coating material to be applied; and the control system is configured to control the heating elements in the coating apparatus, the temperature of the oven and the speed of the wire through the coating apparatus, oven and cooling chamber.']