FDL Double Shaft Mixer

Q: Can the FDL mixer be used for adhesives and sealants?

Yes. The FDL is suitable for viscous adhesive and sealant formulations requiring both material circulation and high-speed dispersion.

Q: Can the Double Shaft Mixer operate under vacuum?

Vacuum dispersing and mixing are available on request and should be selected according to the formulation and process requirements.

Q: What agitator options are available?

Anchor-type and butterfly-type low-speed agitators are available, while single-disc, double-disc and Niemann-type dispersing discs can be selected according to process requirements.

Q: How do I choose the correct FDL model?

Selection should consider working batch capacity, viscosity, density, filler ratio and dispersion requirements before determining tank size, motor power and mixing configuration.

Heavy-duty dual-shaft mixing and dispersing equipment for adhesives, sealants, coatings and other medium- to high-viscosity formulations. The FDL combines low-speed material circulation with high-speed dispersion in the same vessel.

Low-speed circulation + high-speed dispersion

Typical viscosity up to 150,000 cps

Standard tank capacity 150–900 L

Vacuum & variable-speed options available

Mixing Principle

Agitation + Dispersion

Two shafts operate simultaneously

Typical Viscosity

Up to 150,000 cps

Subject to material formulation

Tank Capacity

150–900 L

Standard FDL models listed below

Process Option

Vacuum / Variable Speed

Configured according to process needs

Mixing Principle

How Does the FDL Double Shaft Mixer Work?

High-viscosity formulations need both bulk material movement and localized shear. If material does not circulate effectively, a high-speed disperser may work intensively around the disc while material farther from the active zone moves more slowly.

The FDL addresses both functions with two independently driven shafts: a low-speed scraper agitator moves the overall batch, while a high-speed dispersing shaft works on powders, fillers and agglomerates.

By combining macro-level circulation with localized high-shear dispersion, the FDL supports formulations that are difficult to process with a single mixing element.

Two Mixing Actions in One Vessel Each shaft performs a different process function during the same batch.

Low-Speed Scraper Agitator

Creates continuous bulk circulation throughout the vessel while PTFE scrapers return wall-adhering material to the active mixing zone.

High-Speed Dispersing Shaft

Generates intensive shear around the dispersing disc to wet out powders, break down agglomerates and distribute fillers and additives.

Machine Design

Key Machine Design for Mixing & Dispersion

The FDL is built around two independently driven mixing functions and a vessel-handling system designed for viscous production. The final arrangement can be selected according to material behavior and process requirements.

FDL double shaft mixer machine structure

Low-Speed Scraper Agitator Promotes bulk material turnover while the PTFE scraper continuously returns material from the vessel wall.

High-Speed Dispersing Shaft Provides localized shear for powder wetting, filler incorporation and dispersion.

Precision-Finished Vessel The finished inner surface supports close scraper contact and helps simplify batch cleaning.

Independent Drive System High-speed dispersion and low-speed agitation are driven separately for greater process flexibility.

Hydraulic Lifting System Supports lifting operation for vessel positioning, tank access, cleaning and batch handling.

Heavy-Duty Base Provides stable structural support during production-scale high-viscosity mixing.

Applications & Process Fit

Suitable Materials & Processing Conditions

The FDL Double Shaft Mixer is intended for formulations that need simultaneous material turnover and high-speed dispersion, especially as increasing viscosity reduces natural circulation inside the vessel.

01 / ADHESIVES

Epoxy Adhesives

For incorporating resins, fillers, functional powders and additives into medium- to high-viscosity adhesive formulations.

02 / ADHESIVES

Polyurethane Adhesives

Supports controlled material circulation and dispersion in viscous resin systems containing fillers and additives.

03 / ADHESIVES

Acrylic Adhesives

Suitable where resin systems require simultaneous blending, filler incorporation and high-speed dispersion.

04 / SILICONE

Silicone Adhesives & Sealants

Supports continuous material turnover in viscous silicone-based formulations containing powders, fillers and additives.

05 / FILLED SYSTEMS

Structural Adhesives & Sealants

For filled formulations where both overall circulation and localized dispersion are required during processing.

06 / OTHER MATERIALS

Coatings, Inks & Putties

Additional applications include viscous pigment- or filler-containing coating, ink, putty and polymer systems.

Especially Suitable When Your Process Involves Process behavior is more useful than industry name alone when evaluating mixer fit.

01 Medium- to high-viscosity formulations

02 Powders or fillers requiring dispersion

03 Material adhering to vessel walls

04 Limited natural circulation at higher viscosity

05 Simultaneous mixing and dispersion

06 Vacuum deaeration requirements

Mixer Selection Logic

When Should You Choose an FDL Double Shaft Mixer?

The FDL is most useful when the process needs more than high-speed dispersion alone. Its second shaft is intended to maintain bulk material movement while the disperser works locally at higher shear.

Mixing + Dispersion Are Both Required

Choose a double shaft arrangement when the formulation requires overall circulation together with high-speed dispersion of powders, fillers or additives.

Viscosity Limits Natural Material Turnover

The low-speed scraper agitator keeps viscous material moving through the vessel while the high-speed disperser works in the active shear zone.

A Single High-Speed Disperser Is Not Enough

For more viscous formulations, strong local shear may not provide enough bulk circulation. The additional low-speed shaft supports overall turnover.

Different process? For extremely high-viscosity, paste-like materials with very limited flow, a planetary or double planetary mixer may be more suitable and should be evaluated separately.

Technical Data

FDL Double Shaft Mixer Technical Specifications

Standard model data provides a starting point for equipment selection. Final motor power, agitator structure and process configuration should be confirmed according to the actual formulation and production requirement.

Parameter / Model	FDL-600	FDL-900	FDL-1000	FDL-1200
Tank Capacity	150 L	500 L	600 L	900 L
High-Speed Power	7.5–11 kW	18.5–22 kW	22–37 kW	30–55 kW
Low-Speed Power	4–4.5 kW	7.5–15 kW	11–30 kW	11–37 kW
High-Speed Blade Diameter	200 mm	250 mm	280 mm	330 mm
Low-Speed Mixing Device Diameter	570 mm	860 mm	960 mm	1160 mm
High-Speed Shaft	1500 rpm	1500 rpm	1500 rpm	1500 rpm
Low-Speed Shaft	90–120 rpm	60–120 rpm	120 rpm	120 rpm
Max. Up / Down Range	700 mm	950 mm	1000 mm	1100 mm
Dimensions (L × W × H)	1750 × 1250 × 2350 mm	2420 × 1400 × 3106 mm	2800 × 1700 × 3250 mm	2800 × 1700 × 3250 mm

* Specifications are standard reference data. Final equipment selection may change according to viscosity, density, formulation, batch size, mixing objective and site conditions.

Configuration Options

Available FDL Mixer Configurations

Mixing components, speed control and vessel handling can be selected around material viscosity, dispersion target and production requirements.

Component Available Configuration Selection Basis

Low-Speed Agitator Anchor / Butterfly Selected according to viscosity and required bulk circulation.

Dispersing Disc Single / Double / Niemann Matched to powder wetting and dispersion requirements.

Speed Control Fixed / Variable Frequency Configured according to the required operating speed range.

Wall Scraper PTFE Scraper Returns wall-adhering material to the active mixing zone.

Vacuum Process Available on Request Used when deaeration or reduced air incorporation is required.

Hydraulic System Lift / Lift + Swing Selected according to vessel access and multi-tank operation.

Tank Clamping Belt / Manual / Pneumatic Matched to vessel handling and operating requirements.

Explosion Protection ATEX Option Available Confirmed according to material, solvent and installation conditions.

Typical Process

Typical Double Shaft Mixing Workflow

A typical adhesive or filled formulation may move through the following stages. The actual sequence depends on formulation and production requirements.

Material Loading Liquids and selected raw materials are charged into the vessel.

Pre-Mixing Low-speed agitation establishes initial material circulation.

High-Speed Dispersion The disperser incorporates powders, fillers and additives.

Uniform Mixing Both shafts continue until the required consistency is reached.

Discharge / Transfer The finished batch moves to the next production stage.

Actual mixing sequence and processing time depend on formulation, viscosity, filler loading and required final properties.

Mixer Selection

What We Need to Select Your FDL Mixer

Capacity alone is not enough to select a double shaft mixer. Material behavior and the required processing result affect motor power, agitator structure, dispersing configuration and vessel arrangement.

Material Viscosity Provide starting, processing and expected final viscosity where available.

Batch Capacity Specify required working volume or batch weight rather than only vessel size.

Material Density Density helps evaluate batch load, vessel volume and drive requirements.

Powder / Filler Ratio Filler loading can significantly change material flow and mixing torque.

Dispersion Requirement Define whether the process needs incorporation, intensive dispersion or both.

Vacuum Requirement Confirm whether deaeration or reduced air incorporation is required.

Site Conditions Confirm installation space, electrical requirements and operating environment.

Engineering Support

Integrate the FDL Into Your Adhesive Production Process

The FDL can be supplied as standalone mixing equipment or considered together with material handling, transfer, discharge, filling and packaging requirements when planning a broader adhesive production process.

Raw Material Feeding

Liquids, resins, powders and fillers are prepared and introduced according to the formulation sequence.

FDL Double Shaft Mixing

Low-speed circulation and high-speed dispersion are combined in the main mixing stage.

Vacuum / Transfer

Vacuum and transfer arrangements can be evaluated according to material and downstream process needs.

Discharge / Filling

Finished material can move to discharge or filling equipment according to the production layout.

Packaging

Downstream packaging equipment can be considered when a more complete production line is required.

FAQ

Double Shaft Mixer FAQ

Common questions when evaluating the FDL mixer for adhesives, coatings and other high-viscosity formulations.

What is a double shaft mixer?

A double shaft mixer uses two mixing shafts to perform different functions in the same vessel. The FARFLY FDL combines a low-speed scraper agitator with a high-speed disperser so that material circulation and dispersion can occur simultaneously.

What viscosity can the FDL Double Shaft Mixer handle?

FARFLY specifies the FDL as typically suitable for viscosities up to approximately 150,000 cps. Actual suitability depends on density, formulation, batch volume, filler loading and the required mixing result, so final selection should be confirmed for each process.

Can the FDL mixer be used for adhesives and sealants?

Yes. The mixer is suitable for viscous adhesive and sealant formulations that require both bulk circulation and high-speed dispersion. FARFLY also applies the FDL in silicone and other adhesive production processes.

Can the Double Shaft Mixer operate under vacuum?

Vacuum dispersing and mixing are available on request. The requirement should be confirmed according to the formulation, deaeration target and production process.

What agitator options are available?

Depending on material viscosity and formulation behavior, anchor-type and butterfly-type low-speed agitators are available. Single-disc, double-disc and Niemann-type dispersing discs can also be selected according to the required dispersion result.

Can one mixer work with multiple tanks?

A hydraulic lifting and swing mechanism can be configured for operation with a single tank or multiple tanks, depending on production layout and handling requirements.

Is an explosion-proof configuration available?

ATEX-compliant configuration to II 2GD c IIB T3 is listed as available on request. The final explosion-protection requirement should be confirmed according to the material, solvent system and installation environment.

How do I choose the correct FDL model?

Start with working batch capacity, viscosity, density, filler ratio and dispersion requirement. FARFLY can then evaluate the appropriate tank capacity, motor power, agitator structure, dispersing disc and operating configuration.