Depamu Triple Screw Pumps for Adhesives & Sealants
Introduction
In the industrial processing of adhesives and sealants, fluid transfer equipment faces some of the most demanding operating conditions imaginable. These materials are typically highly viscous, often shear-sensitive, may contain fillers or solid particles, and frequently require precise, pulse-free metering at controlled temperatures. The choice of pumping technology directly impacts product quality, production efficiency, and ultimately, the profitability of manufacturing operations.
Depamu (Hangzhou) Pumps Technology Co., Ltd. has emerged as a leading manufacturer of triple screw pumps specifically engineered to address these challenges. Established in 2003 and headquartered in Hangzhou's Qiantang Area, Depamu is a high-tech enterprise specializing in the research, development, production, and sales of fluid transfer equipment. The company has introduced advanced technology and scientific management systems from Germany, secured over 100 technical patents, and obtained API, CE, ISO 9001, ISO 14001, and ISO 45001 certifications. Its products are now exported to more than 50 countries and regions, including the United States, the United Kingdom, and France.
This article examines the design, operating principles, and key advantages of Depamu triple screw pumps for adhesive and sealant applications, exploring why these pumps have become the preferred choice for manufacturers worldwide.
The Principle of Triple Screw Pump Operation
Depamu triple screw pumps are positive displacement rotary pumps that operate on a simple yet highly effective principle. The pump consists of three intermeshing screws—one power-driven main screw and two driven secondary screws—rotating within a precision-machined casing. As the screws rotate, they create progressively advancing cavities that trap fluid and transport it axially from the suction port to the discharge port without pulsation.
A distinctive feature of Depamu's triple screw pump design is that the main screw and driven screws do not make mechanical contact with each other. Instead, the pumped fluid itself forms a protective film between the screws and between the screws and the liner. This hydrodynamic lubrication principle results in minimal mechanical friction, exceptionally long service life, and reliable operation even under demanding conditions. The company describes this as "semi-permanent" longevity—a claim supported by the pump's robust construction and advanced German-inspired engineering.
Critical Advantages for Adhesive and Sealant Processing
1. Handling High-Viscosity Fluids
Adhesives and sealants span an enormous viscosity range—from low-viscosity cyanoacrylates to extremely thick polyurethanes, silicones, and hot-melt adhesives. Depamu triple screw pumps are specifically designed to excel in high-viscosity applications. The pumps can handle viscosities from 3 to 760 cSt under standard configurations, with specialized designs accommodating even higher viscosities.
Unlike gear pumps or centrifugal pumps that may struggle with thick fluids or suffer from excessive wear, Depamu triple screw pumps maintain consistent volumetric efficiency regardless of viscosity variations. The positive displacement nature of the screw mechanism ensures that each revolution delivers a fixed volume of fluid, making these pumps particularly suitable for applications where viscosity fluctuates due to temperature changes or batch-to-batch variations.
2. Pulse-Free, Continuous Flow
One of the most critical requirements in adhesive and sealant manufacturing is the elimination of flow pulsation. Pulsation can introduce air bubbles, cause inconsistent application weights, and compromise the structural integrity of finished products. Depamu triple screw pumps deliver flow that is "uniform, continuous, and free of pulsation". The fluid moves through the pump in an axial,匀速 linear motion, resulting in minimal pressure fluctuation and exceptional flow stability.
This characteristic is particularly valuable in metering applications, where precise volumetric delivery is essential for maintaining product formulation accuracy. The pumps can be operated at high rotational speeds without sacrificing flow stability, offering manufacturers flexibility in production rate adjustment.
3. Superior Self-Priming Capability
Adhesive and sealant production lines often involve complex piping systems with elevation changes, long horizontal runs, and multiple fittings. Depamu triple screw pumps feature excellent self-priming ability, capable of drawing fluid from suction lifts without requiring foot valves or vacuum assist equipment. This self-priming capability simplifies system design, reduces installation costs, and eliminates the maintenance associated with auxiliary priming devices.
Furthermore, the pumps demonstrate high tolerance for entrained gases and minor contaminants. In adhesive production, where mixing processes can introduce air into the fluid, this characteristic prevents cavitation and maintains consistent pump performance.
4. Temperature Control and Heating Jacket Options
Many adhesives and sealants require elevated temperatures to achieve pumpable viscosities. Hot-melt adhesives, in particular, must be maintained at precise temperatures throughout the transfer process to prevent premature solidification or degradation.
Depamu offers heating jacket configurations for their triple screw pumps, incorporating hydraulic temperature control systems that subject the medium to cold-hot exchange and temperature compensation as it enters the pump head. This design ensures correct addition of temperature-sensitive media and improves the mobility of viscous liquids by leveraging the characteristic that liquid viscosity decreases as temperature rises. The result is fluent delivery and accurate metering even for materials that are solid at room temperature.
The heating jacket design also includes cooling features on mating connection bodies to reduce the adverse effects of excessive heat on mechanical transmission components. This thermal management capability extends pump life and maintains dimensional stability of precision-machined parts.
5. Low Shear and Non-Foaming Operation
Shear sensitivity is a significant concern in adhesive and sealant processing. Many formulations contain polymers, thickeners, or reactive components that can degrade or undergo unwanted reactions when subjected to high shear forces. Depamu triple screw pumps transport fluid with minimal agitation, delivering media "without foam or vortex formation".
The gentle pumping action preserves the rheological properties of shear-sensitive materials, maintaining their viscosity, tack, and curing characteristics. This is particularly important for structural adhesives, sealants containing fillers, and reactive systems where shear-induced heating could trigger premature cross-linking.
6. Compact Design and High-Speed Capability
Despite their robust construction, Depamu triple screw pumps feature a compact, space-efficient design. The small footprint is advantageous in crowded production environments where floor space is at a premium. The pumps can be driven directly by electric motors or other prime movers, eliminating the need for complex belting or gearing systems.
The ability to operate at high rotational speeds allows manufacturers to achieve substantial flow rates without resorting to larger, more expensive pump models. Depamu's DPSN and DP3G series offer maximum flow rates up to 575 m³/h (9,583 L/min) with differential pressures up to 25 bar and maximum speeds of 2,900 r/min.
7. Reliability and Long Service Life
In continuous manufacturing operations, unplanned downtime is extraordinarily costly. Depamu triple screw pumps are engineered for reliability under demanding conditions. The pumps demonstrate "significant advantages under special working conditions of high viscosity, high pressure, and high temperature". They are "not prone to failure and operate reliably," with service life "noticeably longer than gear pumps or Rotor Pumps".
The absence of mechanical contact between rotating elements eliminates the primary wear mechanism that limits the life of gear pumps and other positive displacement designs. The fluid film protection between screws and between screws and the liner ensures that wear is minimal even after years of continuous operation.
Technical Specifications
Depamu offers two primary series of triple screw pumps suitable for adhesive and sealant applications:
DPSN Series:
-
Robust construction with easy installation and maintenance
-
Capable of conveying high-viscosity and high-temperature media without foam or vortex formation
-
Strong self-priming capability
-
Uniform, continuous, pulse-free flow with high volumetric efficiency
-
Low noise operation
-
Compact size with high-speed capability
-
Insensitive to entrained gases and minor contaminants
DP3G Series:
-
Simple structure with multiple configuration options
-
Small flow rates from 0.2 to 6.5 m³/h with integrated pump body and liner
-
Mechanical shaft seals as standard
-
For medium to large flows, separate liner fixed within pump body
-
Double-suction horizontal mounting for large flow models
-
Both mechanical and packed shaft seals available depending on pumped media
-
Marine versions available in horizontal and vertical mounting configurations
Common Specifications (Both Series):
-
Maximum flow rate: 575 m³/h (9,583 L/min)
-
Maximum differential pressure: 25 bar
-
Maximum speed: 2,900 r/min
-
Media viscosity range: 3–760 cSt
For medium and larger flow models, Depamu incorporates safety valves that return high-pressure oil to the pump inlet when pressure exceeds the set point, protecting both the pump and downstream equipment.
Applications in Adhesives and Sealants
Depamu triple screw pumps are widely used across multiple industries, including petroleum, chemical, metallurgy, power, petrochemical, shipbuilding, construction materials, hydraulic systems, and machine tools. Within the adhesives and sealants sector, specific applications include:
Hot-Melt Adhesive Transfer: The heating jacket configuration maintains adhesive at optimal application temperatures during transfer from melting units to application equipment.
Structural Adhesive Metering: Pulse-free, accurate volumetric delivery ensures consistent bondline thickness and adhesive coverage in automated assembly operations.
Sealant Filling and Dispensing: The pumps' ability to handle high-viscosity, filled sealants without degradation makes them ideal for cartridge filling and precision dispensing applications.
Reactive Adhesive Processing: Low-shear operation prevents premature reaction of two-component systems and maintains pot life.
Polymer and Resin Transfer: The pumps efficiently handle the high viscosities typical of polymer melts and resin systems used in adhesive formulation.
Butyl and Polyurethane Sealants: The self-priming capability and tolerance for entrained air are particularly valuable when handling these commonly used construction and automotive sealants.
Industry Recognition and Quality Standards
Depamu's commitment to quality is evidenced by its certifications and industry standing. The company has passed API, CE, ISO 9001, ISO 14001, and ISO 45001 certifications and serves as a drafter of pump industry standards. Its products are utilized by major state-owned enterprises including CNPC, SINOPEC, and CNOOC. Notably, Depamu secured the world's largest Indian oilfield polymer high-pressure reciprocating pump project in 2018, breaking the monopoly of European and American manufacturers in the高端 equipment market.
Conclusion
Depamu triple screw pumps represent a sophisticated engineering solution for the demanding requirements of adhesive and sealant processing. Their unique combination of pulse-free flow, high-viscosity capability, self-priming operation, temperature control options, low shear characteristics, and exceptional reliability makes them indispensable tools for manufacturers seeking to optimize product quality and production efficiency.
The company's German-inspired technology, extensive patent portfolio, and rigorous quality certifications provide assurance of performance and durability. As adhesive and sealant formulations continue to evolve toward higher performance, greater complexity, and more demanding processing requirements, Depamu's commitment to technological innovation positions its triple screw pumps as a trusted solution for the industry's most challenging fluid handling applications.
With over two decades of experience, a comprehensive product range, and a global presence spanning more than 50 countries, Depamu (Hangzhou) Pumps Technology Co., Ltd. continues to advance the state of the art in positive displacement pumping technology, helping manufacturers around the world achieve new levels of productivity and product quality in adhesive and sealant production.