Enclosed Coating Apparatus with Gas-Assisted Inversion
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Solution Overview
Problem
Existing coating technologies for snack foods result in non-uniform and inefficient application of flavorings, leading to high wastage, contamination, and significant downtime for cleaning, with a high percentage of products being coated on one side or not at all, causing inefficiencies and financial losses.
Innovation Solution
A system comprising two enclosed coating stations with a pressurized gas supply and a conveyor that inverts products between stations, ensuring both sides are coated using gas assistance, minimizing atmospheric contamination and allowing for quick cleaning and flavor changes, with electrostatic charging to enhance uniformity and containment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a rotating drum coating system is used, then coating application is achieved, but coating uniformity is poor and product damage occurs
Solution Approach 1:
The coating system is divided into multiple independent coating stations (first coating station, second coating station) that can operate separately. Each station has its own coating substance supply and application mechanism, allowing precise control over coating application on different sides of the product without the mechanical damage caused by rotating drum systems.
Solution Approach 2:
The traditional mechanical rotating drum system is replaced with a conveyor-based system where products are moved through stationary coating stations. This substitution eliminates the mechanical contact and friction that cause product damage while maintaining coating application capability through controlled gas-assisted powder delivery.
2Manufacturing precision
If a narrow chute is used for coating substance delivery, then coating application is localized, but coating coverage is limited to narrow region
Solution Approach 1:
The coating application is extended from a narrow longitudinal region to a broader two-dimensional area by introducing lateral dispersion mechanisms. The coating substance is delivered through chutes and dispersed by gas streams and electrostatic fields to cover a wider region above the conveyor, achieving comprehensive product coverage.
Solution Approach 2:
A pressurized gas stream acts as an intermediary between the coating substance delivery system and the product. The gas stream carries the coating powder laterally and deposits it uniformly across the product surface, expanding coverage without requiring a more complex mechanical delivery system.
3Loss of substance
If open coating systems are used, then coating application is simple, but atmospheric contamination and wastage increase
Solution Approach 1:
Each coating station is enclosed by a hood or enclosure that contains the coating substance and gas stream within a defined space. This enclosure prevents coating powder from escaping into the atmosphere while allowing the coating process to proceed efficiently, reducing wastage without significantly increasing system complexity.
4Productivity
If single-sided coating is used, then processing is simple, but product quality is reduced
Solution Approach 1:
The coating process is segmented into distinct first and second coating stations, each responsible for coating one side of the product. The inverting station positions the product between these stations, enabling systematic double-sided coating. This segmentation allows each station to be optimized for its specific side while maintaining overall processing efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Achieves a 99% effective double-sided coating with minimal waste and improved uniformity, reducing downtime and contamination, while allowing for closer equipment spacing and efficient cleaning, thereby enhancing manufacturing efficiency and product quality.
Implementation Method 1
A pressurised gas stream is used to deliver the coating substance towards the product
Implementation Method 2
the charged powder will be attracted to the products in a generally uniform manner
Implementation Method 3
Upon emerging from an exit nozzle, the substance passes a charging electrode. The charged gas then impacts on the falling coating, dispersing it and imparting a charge to it, and will be attracted to the product in contact with the grounded drum surface
Implementation Method 4
the inverting station is operable to invert product such that, prior to product being transported by the conveyor to said second station
Data Source
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AI summary
The present invention relates to an improved apparatus and method for delivering a coating substance and more particularly, though not necessarily, to an improved apparatus for delivering a powder, liquid, or suspension coating. There exists a wide variety of products that require to be coated with a substance (e.g. powder, liquid, suspension, etc) during their preparation. For example, snack foods such as potato crisps and corn chips are usually coated with flavouring. It is generally desirable to be able to achieve a uniform and controllable coating over the entire surface of a product. A traditional method used for coating snack foods involves the use of a rotating drum, having a 2 - 3m length and a diameter of 0.5 - 1.5m, which has its axis generally aligned with the horizontal, but with a slight tilt. Flavouring in the form of a powder is delivered via an inclined chute to a location within the drum so that the flavouring is sprinkled onto the products to be coated. This technique tends to result in a non-uniform coating of products, with flavour concentration varying between product pieces and across the surfaces of individual pieces. Product can be damaged; flavourings may clump; this can damage the reputation of a brand. Another problem that arises with prior art systems is that, through the use of a rotating drum system, there can be tremendous wastage of coating material. A still further problem associated with the rotating drum systems is that, in the event of a change in the application of a flavour to a snack, there is a considerable downtime taken to clean the apparatus. In terms of an industrial process, this corresponds to a loss of 1/48th - 1/24th manufacturing time in a 24/7 manufacturing facility which is additionally due to cleaning. This can be significant. The present invention seeks to provide an improved coating delivery method and apparatus.