Pulsating Pipe Mold Spigot Connector Pressure Control
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Solution Overview
Problem
The manufacture of double wall corrugated plastic pipes using a pulsating corrugator faces challenges in providing appropriate pressure to support the extruded molded plastic during the shifting of mold blocks, which affects the formation of a reliable spigot connection.
Innovation Solution
A pulsating corrugator system that includes a plurality of main mold blocks for forming double wall corrugated pipes with an inner smooth wall and outer corrugated wall, utilizing at least one secondary mold block to form an inline spigot connection, with a controller managing the movement and pressure of the mold blocks to ensure proper formation and cooling of the spigot corrugations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a pulsating corrugator with main mold blocks is used to form double wall corrugated pipe, then the pipe forming process is efficient and continuous, but the spigot connection formation is difficult because the mold blocks move individually and cannot maintain proper pressure support during shifting
Solution Approach 1:
The mold system is segmented into main mold blocks for pipe forming and a separate secondary mold block specifically for spigot connection forming. This segmentation allows the secondary mold block to be positioned upstream of the extrusion outlets where it can independently form spigot connections with proper pressure support, while the main mold blocks continue their pulsating movement for efficient pipe production.
Solution Approach 2:
The secondary mold block acts as an intermediary element between the extrusion outlets and the main mold blocks. It temporarily holds and forms the spigot connections with appropriate pressure support before transferring them to the main mold blocks for continued pipe formation, thus resolving the pressure support issue during mold block shifting.
2Reliability
If air pressure is used to support extruded plastic during mold block shifting, then the plastic is properly supported, but the pressure must be continuously adjusted which complicates the control system
Solution Approach 1:
The air pressure system is made dynamic with variable pressure control. The controller adjusts air pressure based on the position and operation of the secondary mold block - providing higher pressure when the block is engaged with the spigot connection for proper support, and reducing pressure when the block is moved or released. This dynamic adjustment maintains reliability without requiring complex continuous control.
Solution Approach 2:
The controller monitors the position and operation of the secondary mold block and adjusts air pressure accordingly. This feedback mechanism ensures that pressure is applied at the right time and magnitude to support the extruded plastic during spigot formation, while avoiding unnecessary pressure adjustments that would complicate the control system.
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 system effectively forms an integral male spigot connection as part of the double wall corrugated pipe by varying air pressure and vacuum forces to support the extruded plastic, ensuring accurate shaping and cooling of the corrugations, thereby enhancing the manufacturing process.
Implementation Method 1
The controller varies the pressure of an air supply that introduces support air between said extruded plastic outlets at a first pressure for each corrugation of said first diameter and at a lesser pressure for supporting a last formed spigot corrugation
Implementation Method 2
The controller varies a vacuum force used with said primary mold blocks for forming said corrugations of said first diameter and exerts a reduced vacuum source when the respective main mold block engages a corrugation formed by the secondary mold blocks
Data Source
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AI summary
A pulsating corrugator is provided with at least one secondary mold block that is selectively used for forming a spigot connection as the corrugated or ribbed pipe is formed. Preferably, the primary mold blocks used to form the corrugated pipe are also used to assist in further cooling of the formed spigot connection once released from the secondary mold block. The corrugator also includes a controller used to provide different air pressure as the mold blocks move past extrusion outlets of an associate extruder.