The Market Context
Thailand produced approximately 900,000 metric tons of aquaculture feed in 2023, with Nile tilapia accounting for roughly 220,000 tons of that volume. For decades, much of this tilapia feed was manufactured as sinking steam-conditioned pellets using ring die pellet mills — a process that is mechanically straightforward but nutritionally limiting. Sinking pellets disperse rapidly in pond water, degrade water quality through uneaten feed accumulation, and deny farmers the visual feeding monitoring that floating feed uniquely enables.
A mid-sized independent feed mill in central Thailand’s Nakhon Pathom province recognized both the threat and the opportunity. Local tilapia farmers — many of whom operated cage-culture systems in canals and reservoirs — were increasingly demanding floating extruded feed. The farmers’ rationale was practical:
- Floating feed allows real-time observation of feeding intensity
- Reduces overfeeding by 15–25%
- Keeps uneaten pellets recoverable rather than decomposing on the pond bottom
Yet the mill’s existing ring die pelleting line, installed in 2015 and rated at 2 t/h, was physically incapable of producing floating pellets. The mill management faced a stark choice: invest in extrusion technology or cede market share to larger integrated feed conglomerates.
The Customer’s Challenge
The mill’s production profile at the time of inquiry was as follows: Beyond the product limitation, the mill faced compounding operational pressures. Raw material costs for fishmeal — a critical protein source — had risen 18% year-on-year, squeezing margins on a product already commoditized at the lower end of the market. The mill needed not only a new production capability but also a pathway to higher-margin premium feed that could justify its raw material investment.
Management articulated four specific requirements to prospective equipment suppliers:
Produce floating extruded feed with a bulk density of 0.38–0.45 g/cm³ and water stability exceeding 2 hours.
Achieve a minimum throughput of 1.5 t/h on a tilapia formulation containing 28% crude protein.
Maintain starch gelatinization ≥80% to ensure digestibility and pellet binding without synthetic binders.
Complete installation and commissioning within a 14-day shutdown window to minimize revenue disruption.
Technical Assessment and Equipment Configuration
Hongyang Feed Machinery conducted a two-day on-site survey prior to submitting a proposal. The engineering team assessed not only the physical footprint available for the new extrusion line but also the mill’s existing raw material grinding capability, steam infrastructure, and electrical distribution capacity. Several findings shaped the final configuration:
The existing hammer mill — fitted with a 3.0 mm screen — produced meal with a geometric mean particle diameter of approximately 580 µm, which fell within the 500–700 µm range recommended for single-screw extrusion. Retaining this unit avoided unnecessary capital expenditure.
The mill’s boiler, rated at 500 kg/h saturated steam, had sufficient surplus capacity to supply the conditioner without requiring a new steam generator.
Electrical load analysis revealed 65 kVA of available capacity on the main distribution board, adequate for the proposed 55 kW extruder main motor plus ancillary drives.
The configuration proposed centered on a HYSP-100 single-screw wet-type extruder, supported by a twin-shaft preconditioner, belt dryer, counterflow cooler, and post-extrusion coating system.
Barrel & Screw Configuration Notes:
The extruder barrel configuration was specified with four independently controlled temperature zones, allowing the operator to build a progressive thermal profile from feed inlet (Zone 1) to die plate (Zone 4). The screw profile included two shear-lock segments positioned at Zones 2 and 3 to increase mechanical energy input and ensure complete starch gelatinization — a design choice validated by published research demonstrating that shear-lock placement affects both specific mechanical energy (SME) and pellet expansion ratio in cereal-fishmeal formulations.
Process Parameters and Quality Control
Commissioning took nine days — three days ahead of the scheduled window — during which Hongyang service engineers worked alongside the mill’s operators to establish stable running parameters for the primary tilapia formulation. The following operating window was documented and incorporated into the mill’s standard operating procedures.
Operational Note — Buoyancy Variability Issue
During the first three production days, pellet buoyancy showed unacceptably high variability, with approximately 15% of sampled pellets failing to float beyond 30 minutes. Root-cause analysis traced the problem to inconsistent steam quality — specifically, wet steam carryover from the boiler during peak demand cycles.
The solution was twofold:
- Installation of a steam separator trap immediately upstream of the conditioner
- Reduction in steam header pressure from 6 bar to 4.5 bar, which improved steam dryness without compromising conditioning temperature
This episode, while minor, illustrates an important principle: the success of extrusion technology depends as much on auxiliary utility management as on the extruder itself.
Results
Six months of post-installation production data were collected and benchmarked against the pre-project baseline.
FCR Improvement — On-Farm Economics
The improvement in FCR is particularly significant when viewed through the lens of on-farm economics. At a typical tilapia harvest weight of 600 grams and a feed cost of approximately THB 18 per kilogram, the reduction from FCR 1.7 to 1.4 represented a feed-cost saving of approximately THB 3.24 per fish.
For a medium-scale cage farmer producing 50,000 fish per cycle, this equated to over THB 160,000 in annual savings — a compelling commercial argument for adoption.
The Service Dimension
What distinguished this project from a simple equipment transaction was the depth of on-site engineering support. Hongyang service engineers remained embedded at the mill for the full 14-day commissioning period, and one senior process engineer stayed for an additional week after handover to mentor the operations team through the first unsupervised production runs.
Specific support activities included:
Documentation of complete extrusion parameter matrices for three tilapia formulations (starter crumble, grower 3 mm, finisher 4 mm).
Training of four line operators on startup/shutdown sequencing, die-plate changeover procedures, and basic troubleshooting of pellet density and shape irregularities.
Implementation of a simple quality-control checklist for hourly sampling of pellet buoyancy, bulk density, and moisture.
Recommendations for screw and barrel preventive maintenance intervals based on observed wear patterns during the first 200 hours of operation.
This level of post-installation engagement is not incidental. Extrusion cooking for aquafeed is a process that sits at the intersection of mechanical engineering, cereal chemistry, and practical mill operation. Equipment performance guarantees, however credible, are only fully realized when the operators who run the line understand not just what the parameters should be, but why.
Conclusion
The transition from sinking pellets to floating extruded feed represents far more than a production line upgrade — it is a strategic repositioning of a feed mill’s product portfolio and market identity. For the Thai mill in this case, the investment in Hongyang extrusion technology delivered on all four original requirements:
Floating feed with over two hours of water stability
Throughput meeting the 1.5 t/h target
Starch gelatinization consistently above 80%
Commissioning timeline that beat the 14-day shutdown window
The deeper lesson, however, lies in what happens after commissioning. Equipment specifications and process parameters can be written into a manual, but the knowledge transfer, troubleshooting partnership, and operational discipline that turn a new extruder into a sustainable competitive advantage require something less easily codified: a supplier’s genuine commitment to seeing the project through to measurable customer success.
Post time: May-27-2026
