Our novel elements are applied directly to the article to be heated using a short, “straight-through” process.
This contrasts sharply with the (typically) 27+ stage process to produce conventional coiled wire elements, involving 7 different industry sectors.
Production Benefis - This vastly simplified process results in significant economic and operational benefits for our licensees.
Outline of the rapid, low capital cost process used:
1. Metal powders, consisting of alloys of nickel, chromium (IV valence) and iron are supplied as pre-oxidised powders of a defined particle size range, composition and degree of oxidation. These are applied, using a ‘flame-spraying’ process with specially adapted guns, directly onto the substrate in question and using ‘masks’ to control the size and shape of element applied. Where the flame spraying is done utilising a computer controlled robot, the shape and form of the element can be of any configuration that can be described by a mathematical equation to control the robot carrying the flame-spraying gun (e.g. circular, tubular, flat, elliptical, hemispherical, etc.). Powder feed rates, gas flow rates, speed of traverse of the robot, ‘flight’ distance, thickness of deposit, number of layers deposited and direction of deposit are all controlled variables. Deposits of between 50-250 microns thickness are typically applied, depending on purpose, using this technique. Variable thickness within a single element can also be produced, if required.
2. In certain circumstances, a high dielectric base coat is pre-applied to the substrate before applying the pre-oxidised metal powders.
3. Electrical contact strips (usually of metallic copper powder) are flame-sprayed onto the applied elements at appropriate positions.
4. The final resistance of the heating elements (and thereby the power rating in use) is finally adjusted using a patent-pending high voltage pulsing sequence, referred to as “conditioning”. This works by creating more conductive pathways through the metal/ metal-oxide heating element matrix, progressively opening-up more such pathways, until the desired resistance value is achieved.
MANUFACTURING PROCESS AND BENEFITS: