Flexible plastic pipes for irrigation, conduits, and tubing are most commonly manufactured from which polyolefin?

Introduction / Context:
Pipe and tubing materials must balance flexibility, toughness, and processability. Within the polyethylene family, density (and branching) strongly affects stiffness and bendability of extruded pipes.

Given Data / Assumptions:

• “Flexible” implies high elongation and easy bending without kinking.
• Applications include small-diameter irrigation lines and general tubing.
• Commodity thermoplastics are under consideration.

Concept / Approach:
LDPE has significant chain branching, reducing crystallinity and modulus, which increases flexibility—ideal for flexible pipes and tubes. HDPE is stiffer and used for pressure pipes and gas mains. PP is stiffer than LDPE and has lower low-temperature toughness. Unsaturated polyesters are thermosets, not typically used for extruded flexible pipes.

Step-by-Step Solution:
Relate flexibility requirement to polymer structure.Select LDPE for its lower modulus and higher ductility.Eliminate HDPE/PP (stiffer) and thermoset polyester (unsuitable for flexible extrusion).

Verification / Alternative check:
Datasheets for LDPE tubing show high elongation and low bend radius; HDPE datasheets emphasise stiffness and pressure rating.

Why Other Options Are Wrong:
HDPE/PP: better for rigid pipes; reduced flexibility versus LDPE.Unsaturated polyester: used in FRP composites, not flexible pipe extrusion.

Common Pitfalls:
Assuming all “polyethylene” grades have the same flexibility; density and branching matter greatly.

Final Answer:
Low-density polyethylene (LDPE)