ANALYSIS OF POWDER COATING LINE HEATING SYSTEM
The heating system of a powder coating line is a crucial part of the entire coating process!
Electric curing oven is widely used due to easy temperature control. The use of far infrared heating is more popular than the traditional resistance wire heating, to save energy, shorten the heating time and reduce production costs.
At present, in order to save energy, reduce production costs, curing furnace with resistance wire heating has been gradually reduced, widely used infrared or far-infrared heating measures.
Silicon carbide far-infrared heating plate heating quickly, but generally each plate power are in 1-2KW, the heat is too concentrated, easy to view the local baking yellow image, and the electrical load leads to a large junction is often easy to burn off; Carbonized clams plate repeatedly warming, cooling, easy to rupture, and warming delay, heat capacity is larger.
Quartz far-infrared heating tube heat is not concentrated, rapid warming, its own heat capacity is small, low buffer capacity after thermostatic power failure, and transparent appearance, easy to observe the working condition in time for maintenance, but easy to break is the biggest shortcoming, should pay close attention to the possibility of workpiece falling down smashed caused by a short-circuit even electricity, must have a protective net.
Low carbon steel far infrared heating tube heat capacity than quartz tube, pre-temperature than the quartz tube is slow, thermostatic power-off buffer capacity than the quartz tube, thermostatic cycle is long, its own strength is good, there are a wide range of applications in the market.
General electrostatic powder coatings require 180℃ ± 5℃ environment, curing 20min to achieve full curing. In order to maintain a uniform temperature in the curing oven there is generally a hot air circulation device. Hot air circulation device should be generally in the curing oven temperature is higher than 150 ℃ before the start of circulation. Curing oven is generally equipped with automatic temperature control instrument, automatic timer and alarm device (through the type of curing oven is only equipped with automatic thermostat device, depending on the conveyor chain running speed to determine the curing time).
The use of spray line equipment for thick-walled workpieces or cast iron workpieces, due to its large heat capacity, the curing temperature must be appropriately elevated in order to achieve a normal curing effect (cast iron parts are generally preheated to 200 ℃, curing at around 190-210 ℃ , with about 30min ).