Radiation Screen for Blow Molding Preform Heating
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Solution Overview
Problem
Existing blow molding machines face inefficiencies in heating preforms due to heat losses through gaps in transport mandrels and radiation absorption by device components, leading to inconsistent temperature profiles and increased energy consumption.
Innovation Solution
A heating device with a radiation screen that overlaps with a support ring to shield the preform's mouth area from thermal radiation, reducing heat loss and ensuring a well-defined temperature profile, while also preventing preforms from slipping during transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If preforms are transported through a heating device using conventional transport mandrels, then the preforms can be heated, but heat losses occur through gaps in the transport mandrels and radiation is absorbed by device components, leading to inconsistent temperature profiles and increased energy consumption
Solution Approach 1:
A radiation screen is introduced as an intermediary component between the heating radiation source and the preform support ring. This screen selectively blocks thermal radiation from reaching the mouth area of preforms and device components while allowing the desired heating of the preform body to proceed, thereby reducing heat loss and improving temperature profile consistency
Solution Approach 2:
The radiation screen is positioned specifically to cover only the mouth area of the preform and the support ring, rather than the entire preform. This localized shielding approach allows the body of the preform to receive necessary heating radiation while protecting the mouth area and surrounding components from excessive radiation, optimizing both energy efficiency and temperature distribution
2Loss of energy
If the radiation screen is positioned to shield the preform mouth area, then heat loss is reduced and temperature profile consistency is improved, but the complexity of the heating device increases
Solution Approach 1:
The radiation screen serves multiple functions simultaneously: it shields the preform mouth area from excessive radiation, protects the support ring from heat accumulation, reduces overall heat loss from the heating device, and helps maintain consistent temperature profiles. This multi-functionality justifies the additional component by delivering multiple benefits from a single addition
3Device complexity
If the support ring is exposed to thermal radiation, then the heating process is simpler, but the support ring absorbs heat leading to heat loss and potential deformation of the preform mouth area
Solution Approach 1:
The radiation screen is positioned in advance to block thermal radiation from reaching the support ring before the radiation can cause harmful heat accumulation. This preliminary protective action prevents the support ring from absorbing excessive heat that would lead to energy loss and potential deformation of the preform mouth area
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 enhances the efficiency of the heating process by minimizing heat loss and maintaining a consistent temperature profile, improving the quality of the blow molding process and reducing energy consumption.
Implementation Method 1
heating radiation of which is emitted in a near-infrared range
Implementation Method 2
equipped with a large number of mirror surfaces in order to avoid or at least greatly reduce absorption of the thermal radiation by components of the heating section and to reflect the NIR radiation back onto the preform
Implementation Method 3
radiation screen that overlaps with a support ring to shield the preform's mouth area from thermal radiation
Data Source
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AI summary
The invention relates to a heating device (H), comprising a heating section (24) for thermally conditioning preforms (1) consisting of thermoplastic material, having an upper mouth section (21) having an opening, a collar-like supporting ring (54) arranged below the mouth section (21), and a bottom section (56) closed at the lower end, to a temperature profile suitable for blow molding, wherein the heating device (H) has transport means (33) for transporting the preforms (1) along a transport path (55) of the heating device (H), and wherein the transport means (33) each bear at least one handling means (41) for holding and handling the preforms (1), wherein a radiation shield (52), which is forced to follow the transport path of the preforms (1), is arranged in an intermediate space between two handling means (41) each provided for handling a preform (1), said radiation shield having, at least on one end face, a recess (53) for partially engaging around a preform (1) held in the handling means (41) that is adjacent to the recess (53), wherein the radiation shield (52) is arranged in such a way that a surface area of the radiation shield (52) overlaps, on the side of said surface area facing away from the opening section (21), with a surface area of the supporting ring (54) as viewed in the longitudinal direction of the preform (1), at least at times during the transport of the preforms (1).