Volumetric Cavity Pump Metering for Hot-Melt Adhesive Coating
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Solution Overview
Problem
Existing adhesive distribution systems for polyurethane reactive hot-melt adhesives face challenges in accurately dispensing small amounts, leading to glue leakage and unsatisfactory product quality, with maintenance being time-consuming and laborious.
Innovation Solution
A volumetric cavity pump (VCP)-embedded metering distribution assembly with specially designed flow passages and gear sets, including a pressure control check valve and control valve assembly, to ensure precise fluid distribution and prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a gear pump is used to distribute polyurethane reactive hot-melt adhesive, then the adhesive can be supplied through a heated hose, but the residence time of the adhesive in the heated hose exceeds the pot life and accurate distribution cannot be achieved
Solution Approach 1:
The patent extracts the adhesive distribution function from the heated hose system and implements it directly at the nozzle through a distribution head with integrated metering cavities. This eliminates the heated hose from the adhesive path, removing the source of excessive residence time while maintaining the ability to supply and distribute the adhesive accurately.
Solution Approach 2:
The distribution head is segmented into multiple independent metering cavities, each with its own nozzle and flow control. This segmentation allows precise control of adhesive quantity to each application point, enabling accurate distribution of small amounts of adhesive without requiring long residence times in a common supply line.
2Manufacturing precision
If a dedicated volumetric cavity pump distributor is used to accurately coat small amounts of hot-melt glue, then adhesive distribution precision is improved, but obvious droplets accumulate at the tip of the nozzle and glue leakage occurs
Solution Approach 1:
The patent implements a motorized drive system that can dynamically reverse the rotation direction of the gear pump. This dynamic control allows the system to not only dispense adhesive with high precision but also to reverse flow and clear residual adhesive from the nozzle tip, preventing droplet accumulation and leakage that would occur with static or unidirectional systems.
Solution Approach 2:
The intelligent controller monitors the distribution process and controls the motor reversal function based on operational parameters. This feedback mechanism ensures that the system can detect and correct conditions that would lead to glue leakage, maintaining manufacturing precision while eliminating the harmful effects of droplet accumulation.
3Productivity
If the gear pump operates to distribute adhesive, then adhesive can be delivered to the nozzle, but adhesive ends accumulate on the surface of the coated object leading to unsatisfactory appearance
Solution Approach 1:
The motorized drive system performs periodic reversal of the gear pump rotation at controlled intervals or upon completion of distribution cycles. This periodic action clears residual adhesive from the nozzle tip at regular intervals, preventing the formation of adhesive ends and droplets that would mar the coating quality, while maintaining high productivity during the actual distribution phase.
4Reliability
If a sealed melter unit and heated hose system is used for polyurethane reactive hot-melt adhesive, then the adhesive can be supplied in a closed container, but maintenance is time-consuming and laborious
Solution Approach 1:
The patent extracts the adhesive from the heated hose system and delivers it directly to the distribution head through a minimized supply path. This eliminates the heated hose that would require maintenance for temperature control and potential clogging, reducing maintenance effort while maintaining the sealed container system's reliability for preserving adhesive integrity.
Solution Approach 2:
The distribution head is designed with a compact, integrated structure that consolidates multiple functions (metering, distribution, and nozzle control) into a single unit. This dimensional consolidation simplifies the overall system architecture, making maintenance more accessible and reducing the labor required compared to distributed components throughout a heated hose 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 achieves high-precision adhesive distribution with reduced maintenance efforts, eliminating glue accumulation and leakage, and maintaining adhesive quality.
Implementation Method 1
a gear set located in the aperture of the gear fixing plate, the gear set having a fluid inlet and a fluid outlet on a side of the gear set opposite to the fluid inlet
Implementation Method 2
a volumetric cavity pump (VCP)-embedded coating system
Data Source
AI summary
A metering distribution assembly and a coating system. The metering distribution assembly includes a volumetric cavity pump that comprises a flow passage plate having flow passages, a nozzle plate with a flow passage, a gear fixing plate attached between the flow passage plate and the nozzle plate, and a gear set located in an aperture of the fixing plate. The gear set has a fluid inlet and a fluid outlet on a side of the gear set opposite to the fluid inlet. The fluid inlet is in fluid communication with the flow passages of the flow passage plate, and the fluid outlet is in fluid communication with the flow passage of the nozzle plate. A part of the flow passages of the flow passage plate, which is in direct fluid communication with the fluid inlet, extends in a direction parallel to a rotation axis of the gear set.