Sterilizing Plastic Preforms Before Forming
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Solution Overview
Problem
Existing methods for sterilizing plastic containers are inefficient and costly, as they require large amounts of sterilizing agents and can damage heating devices due to the use of aggressive gases like hydrogen peroxide, and often involve sterilizing finished containers rather than preforms, which have a larger surface area.
Innovation Solution
A device that heats plastic preforms and then applies a flowable medium, such as hydrogen peroxide gas, to the inner wall of the preforms before reshaping them into containers, using a sterilization device positioned between the heating and shaping units to prevent damage to the heating device and optimize sterilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sterilization is performed on finished containers, then the inner wall is sterilized, but a large amount of sterilizing agent is required due to the large surface area
Solution Approach 1:
The patent applies sterilizing agent to the preform before blowing into the final container shape. This preliminary sterilization action occurs when the preform has a smaller surface area, reducing the total amount of sterilizing agent required while still achieving effective sterilization of the inner wall that will contact the product
2Reliability
If aggressive gases like hydrogen peroxide are used for sterilization, then sterilization effectiveness is improved, but the heating device can be permanently damaged
Solution Approach 1:
The patent divides the production process into separate functional zones: a heating zone and a sterilization zone. The heating device and sterilization device are spatially separated, allowing aggressive sterilizing agents to be applied without exposing the heating device to damaging chemicals, thus protecting the heating device while maintaining sterilization effectiveness
3Device complexity
If sterilization is performed in the heating device, then the process is integrated, but the heating device is attacked by aggressive gases
Solution Approach 1:
The patent segments the production line into distinct functional units: heating device, transport device, and sterilization device arranged in sequence. This spatial segmentation allows each device to perform its specific function without exposure to harmful substances from other processes, eliminating corrosion while maintaining process integration through the coordinated sequence of operations
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
This method allows for cost-effective and efficient sterilization of plastic containers by applying the sterilizing agent to preforms before they are reshaped, reducing the amount of sterilizing agent needed and minimizing damage to the heating device, while ensuring the inner walls are sterilized before the forming process.
Implementation Method 1
a heating device (4), which heats plastic preforms (10)
Implementation Method 2
a sterilization device (30) which applies a flowable medium, in particular gaseous hydrogen peroxide, to a wall and in particular an inner wall or a region of this inner wall of the plastic preforms (10) in order to sterilize this inner wall
Data Source
Figure 1
AI summary
A device (1) for manufacturing plastic containers (20), comprising a heating device (4) which heats plastic preforms, a transport device (12, 14, 16, 18) which transports the plastic preforms (10) along a predetermined transport path (T), and a forming device (8) arranged downstream of the heating device (4) along the transport path, which forms the plastic preforms into plastic containers. According to the invention, the device (1) includes a sterilization device (30) which applies a flowable medium to a wall of the plastic preforms (10) in order to sterilize this wall, wherein this sterilization device is arranged with respect to the transport path of the containers such that the sterilization takes place after the end of the heating process of the containers in the heating device (4) and before the end of the forming process in the forming device.