The Techdreno KC line — which does not require a geotextile sleeve — is not a marketing decision: it is backed by a doctoral thesis defended at the Federal University of Lavras (UFLA) in 2025, which compared the hydraulic performance of thin knife-cut slotted drains against conventional larger-orifice drains, with and without a sleeve.
What the research evaluated
The thesis “Hydraulics of Slotted Drains Without Envelope Material,” by Flávia Vilela Corrêa, aimed to evaluate and compare water intake capacity, discharge rates, and solid transport rates between drains with smaller knife-cut orifices and conventional drains — with and without a geotextile sleeve.
What the results showed
The conventional drain, having larger orifices, showed lower entrance resistance and greater effective radius — meaning it lets water in with less flow opposition. But that same larger orifice that increases the discharge rate also favors solid transport: more water gets in, but more sediment comes with it.
The knife-cut (KC) drain showed solid transport rates similar to a conventional drain with a geotextile sleeve — without needing the sleeve. The sleeve, when used, facilitates water inflow, but its performance can be compromised by clogging, especially in low-cohesion soils.
Thesis conclusion
According to the research, the knife-cut drain offers a more stable and controlled flow, favoring prolonged drainage, and represents a more economical, easier-to-install solution. The geotextile sleeve is not essential for this drain format, because the thin slits themselves already control particle transport — the same logic behind the Techdreno KC line.
Full reference
CORRÊA, Flávia Vilela. Hidráulica de drenos ranhurados sem material envoltório. Doctoral thesis (Water Resources) — Federal University of Lavras, Lavras, 2025.