Prefabricated Concrete Pipe With Thermoplastic Lining and Thermoset Fittings
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Solution Overview
Problem
Conventional prefabricated concrete parts for shaft construction, especially sewage shafts, face challenges in achieving a smooth and chemically resistant lining due to the high cost and thermal expansion issues associated with thermoplastic materials, while thermoset plastics offer advantages in cost-effectiveness and stability but are complex to produce for large components.
Innovation Solution
A prefabricated part with a concrete body lined internally and at connection ends with thermoplastic materials, using a thermoplastic strip embedded with connecting means to integrate with both thermoplastic and thermoset plastic components, allowing for a cost-effective and stable connection through welding or gluing, ensuring a tight overlap and anchoring within the concrete body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermoplastic material is used for lining the pipe inner side, then chemical resistance and smooth surface are improved, but manufacturing cost increases and thermal expansion issues occur
Solution Approach 1:
The pipe is divided into two distinct zones: the pipe inner side lined with thermoplastic material for chemical resistance, and the connection form area covered with thermosetting plastic for cost-effectiveness and dimensional stability. This segmentation allows each material to be used where it provides the most benefit.
Solution Approach 2:
Different material properties are applied to different locations of the pipe. The thermoplastic lining is applied locally to the pipe inner side where chemical resistance is critical, while thermosetting plastic is used locally at the connection forms where dimensional stability and cost are priorities.
2Reliability
If thermoplastic material is used for complex components like connection forms, then chemical resistance is improved, but manufacturing cost increases significantly due to large injection molds
Solution Approach 1:
The connection form is segmented from the main pipe body and covered with a separate molded part made of thermosetting plastic. This allows the complex connection form to be manufactured using cost-effective thermosetting plastic rather than expensive thermoplastic injection molding.
Solution Approach 2:
Thermosetting plastic is applied locally to the connection form area where chemical resistance is less critical than in the pipe interior, but dimensional stability and manufacturing cost are more important.
3Reliability
If thermoplastic material is used for connection forms, then chemical resistance is improved, but dimensional stability deteriorates due to high coefficient of thermal expansion
Solution Approach 1:
The connection form area is segmented and covered with thermosetting plastic material that has low thermal expansion, ensuring dimensional stability during outdoor storage and handling, while the pipe interior maintains thermoplastic lining for chemical resistance.
Solution Approach 2:
Thermosetting plastic with superior dimensional stability is applied locally to the connection forms where precise dimensional control is critical for proper assembly, while thermoplastic is used in the pipe interior where chemical resistance is the priority.
4Ease of manufacture
If thermosetting plastic is used for lining, then manufacturing cost is reduced, but production complexity increases for large components
Solution Approach 1:
The pipe is segmented into zones where thermosetting plastic is used for the connection forms (simplifying production compared to thermoplastic injection molding) while thermoplastic lining is used for the pipe interior. This segmentation optimizes both cost and production complexity.
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 solution combines the cost-effectiveness and chemical resistance of thermoplastics with the stability of thermoset plastics, providing a durable and economically viable prefabricated part with reduced thermal expansion issues, ensuring a tight and long-lasting connection in shaft construction.
Implementation Method 1
The strip is connected to the molded part via one or more connecting means which is/are at least partially embedded or received in both the strip and the molded part, and that the strip is connected to the lining via a joint.
Data Source
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AI summary
A precast element (1a, 1b) comprises a concrete body (2) in the form of a pipe with two pipe ends (3, 4) and an inner pipe surface (5). The inner pipe surface (5) is at least partially lined by a plastic lining (6) connected to the concrete body (2), and at least one of the pipe ends (3, 4) is at least partially covered by a plastic fitting (9, 10) connected to the concrete body (2). At least the partially covered pipe end (3, 4) has a connection shape for connecting the pipe end (3, 4) to a pipe end (4, 3) of another precast element (1b, 1a). The lining (6) is made of a thermoplastic material, and the fitting (9, 10) is made of a thermosetting plastic. The lining (6) and the fitting (9, 10) are tightly connected to each other.