Vacuum Process Roller With Heated End Caps For Uniform Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vacuum coating installations face challenges in achieving uniform temperature distribution on process rollers for substrates in strip form, particularly at the periphery, due to inadequate radiant heating and inefficient cooling processes, leading to temperature gradients and increased servicing efforts.
Innovation Solution
A vacuum-tight process roller design with flattened, outwardly curved hemispherical end caps and a radiant heater extending into the end caps, utilizing a lightweight high-grade steel construction and infrared heating rods, ensures even heating of the peripheral zone and facilitates easy servicing by maintaining a controlled vacuum environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If elongated radiant heaters are used in the process roller with overlength in relation to the width of the substrate, then the middle region of the lateral surface receives sufficient radiant power, but the outer regions and end faces are exposed to less radiant power causing lower temperatures at the periphery
Solution Approach 1:
The radiant heater is divided into multiple independent heating zones along the axial direction of the process roller. Each zone can be independently controlled to provide uniform heating distribution, ensuring that both the middle region and peripheral regions receive adequate radiant power for maintaining consistent temperature across the entire roller surface.
Solution Approach 2:
Different regions of the process roller are provided with different heating characteristics. The peripheral regions and end faces are equipped with additional localized heating elements or adjusted heating intensity to compensate for the lower radiant power exposure, ensuring uniform temperature distribution across all areas of the roller surface.
2Reliability
If the process roller is made vacuum-tight with insulated interior space to prevent contamination, then servicing effort is reduced, but the structure becomes more complex
Solution Approach 1:
The vacuum-tight sealing function is integrated into the existing process roller structure by providing a vacuum connection between the interior space and the vacuum process chamber. This merging of functions eliminates the need for separate insulation and sealing components, reducing structural complexity while maintaining contamination prevention.
Solution Approach 2:
The process roller interior space serves multiple functions: it acts as a vacuum-sealed environment for contamination prevention, a thermal mass for temperature control, and a structural component for mechanical support. This multi-functionality reduces the need for additional separate systems, simplifying the overall structure.
3Ease of operation
If the process roller is cooled down before servicing in batch systems, then work can be carried out safely, but the cooling time increases the total servicing duration
Solution Approach 1:
A cooling channel is provided in the process roller that allows cooling medium to flow through the interior space before servicing is required. This preliminary cooling action can be initiated in advance, allowing the roller to cool down more efficiently and quickly, thereby reducing the total servicing time while ensuring safety.
Solution Approach 2:
A cooling medium (such as gas or liquid) is introduced as an intermediary to transfer heat from the process roller interior space to the external environment. This intermediary cooling mechanism enables faster and more controlled cooling, reducing the cooling-down time required before safe servicing can begin.
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
The solution achieves better heating of the peripheral zone, reduces temperature gradients, and allows for quicker cooling while minimizing contamination and servicing efforts, ensuring consistent coating temperatures and efficient operation.
Implementation Method 1
A heat source, for example one or more radiant heaters that are arranged inside the process roller, is used for this purpose. The heat transfer to the substrate in strip form takes place by thermal conduction as a result of the contact of the substrate in strip form with the roller body
Implementation Method 2
The heat transfer to the substrate in strip form takes place by thermal conduction as a result of the contact of the substrate in strip form with the roller body
Implementation Method 3
In order to achieve this, a sufficient vacuum must be generated inside the process roller. This can either be achieved by the interior space of the process roller being provided with the same vacuum that also prevails in the rest of the vacuum process space
Data Source
AI summary
A process roller for receiving and guiding substrates in strip form in vacuum coating installations. The process roller comprises a heater located inside the process roller, in the form of an elongated radiant heater, and also a cylindrical lateral surface for receiving a substrate in strip form, the process roller being mounted rotatably about an axis of rotation in a vacuum process chamber. A particularly uniform temperature distribution can be achieved on the process roller's lateral surface by the process roller (2) being configured in a vacuum-tight manner, by the lateral surface (3) of the process roller (2) being connected in a vacuum-tight manner to two end caps (4, 5), which have a flattened, outwardly curved hemispherical form, by the interior space of the process roller (2) being connected to a vacuum connection (6), and by the radiant heater (8) extending into the region of the end caps (4, 5).