Multiple Durometer Bulb Seal Cooling Method
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Solution Overview
Problem
Conventional co-extrusion processes for making bulb seals result in cooling differentials between the mounting and bulb portions due to different durometers, leading to compromised part dimensions, tolerances, and structural integrity, with the bulb portion not being effectively cooled internally and the mounting portion experiencing curvature or waviness.
Innovation Solution
A method involving multiple extruders, calibrator devices, and cooling tanks arranged in-line to cool the structural member and bulb portion separately, ensuring uniform cooling and maintaining the desired profiles of both components before cutting to length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional co-extrusion process is used to make bulb seals with different durometers, then the mounting portion and bulb portion can be formed in a single continuous extrusion, but the different cooling rates of the two portions cause dimensional tolerances and structural integrity issues
Solution Approach 1:
The patent divides the continuous extrusion process into two separate segments: the mounting portion is extruded and cooled in a first cooling tank, then the bulb portion is extruded and cooled in a second cooling tank. This segmentation allows each portion to be cooled independently at rates appropriate to its material properties, preventing dimensional tolerance issues while maintaining continuous production.
Solution Approach 2:
The patent applies different cooling conditions to different portions of the bulb seal based on their specific material requirements. The mounting portion (higher durometer) and bulb portion (lower durometer) each receive tailored cooling rates through separate cooling tanks, ensuring that each local region is cooled at the optimal rate for its material composition and structural requirements.
2Device complexity
If conventional single cooling tank process is used, then the processing equipment is simpler, but the bulb portion cannot be effectively cooled from the inside due to the continuous extrusion preventing water entry
Solution Approach 1:
The patent segments the cooling system into two separate cooling tanks, allowing the bulb portion to be cooled independently. The second cooling tank can effectively cool the bulb portion from the inside because the continuous extrusion has already been formed and cut, allowing cooling medium access to the interior of the bulb portion during the second cooling stage.
Solution Approach 2:
The mounting portion is first extruded, cooled, and stabilized in the first cooling tank before the bulb portion is extruded and cooled in the second cooling tank. This preliminary action of cooling the mounting portion first establishes a stable base structure, allowing subsequent cooling of the bulb portion without compromising the overall structural integrity.
3Productivity
If conventional co-extrusion with single cooling is used, then the processing steps are fewer, but the mounting portion experiences curvature and waviness due to cooling differentials
Solution Approach 1:
The patent segments the cooling process into two separate stages with dedicated cooling tanks for each portion. This prevents the cooling differentials that cause curvature and waviness by ensuring that the mounting portion is cooled uniformly first, then the bulb portion is cooled separately, eliminating the thermal gradients that would otherwise cause surface defects.
Solution Approach 2:
Each portion receives localized cooling appropriate to its material properties and geometric requirements. The mounting portion is cooled at a rate optimized for its higher durometer material and structural function, while the bulb portion is cooled at a different rate suited to its lower durometer material and sealing function, preventing surface irregularities in both regions.
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 approach prevents cooling differentials, enhances the quality of multiple durometer bulb seals by ensuring consistent cooling and maintaining the structural integrity and tolerances of both the structural member and the bulb portion, reducing processing complexities and costs.
Implementation Method 1
provide a cooling medium flow thereto
Data Source
AI summary
Method for making multiple durometer bulb seals includes cooling separately at least one structural member and at least one bulb portion of the bulb seal, which have different durometers and shapes. At least a first extrusion is drawn through a die of an extruder for forming a structural member profile and the extruded material is pulled by a first pulling device along a longitudinal axis to a first calibrator device and then through a first cooling tank to cool the structural member profile to a predetermined temperature. Cooling medium directly contacts the outer and inner surfaces of the first profile. The bulb portion is extruded and attached onto the cooled structural member and pulled downstream to a second calibrator device and through a second cooling tank to cool the profile a predetermined amount. Disparity in cooling expansion and cooling differential between the multiple durometers and shapes is avoided or overcome.