HDPE Recycling

Why recycle HDPE — and why it’s easier than you think

Brazil generates over 11 million tons of plastic waste per year. In the US, studies indicate that plastics account for 12% of landfills — and of this total, 19% is HDPE. An extraordinary amount of raw material that could return to the production chain.

HDPE is the plastic with the greatest potential for recycling among technical plastics:

• Does not contain chlorine (like PVC) — simpler, cheaper, and safer recycling for the environment
• Stable mechanical properties after multiple cycles — does not “degrade” with reprocessing
• SPI Code 2 — accepted in almost all selective collection systems worldwide
• Flotation separation — HDPE floats in water (density 0.94–0.96 g/cm³), separating it from PVC, PET, and other plastics in a simple way without chemical reagents
• 1.75 kg of oil are used to produce 1 kg of virgin HDPE — each kilogram recycled saves this non-renewable resource

Recycling HDPE is not just an environmental responsibility — it’s a rational economic decision based on solid technical grounds.

The HDPE Recycling Process — step by step

From collection to final product, recycled HDPE goes through a controlled industrial process in 7 stages:

1. Collection and sorting: separation of HDPE from other waste. HDPE floats in water — a simple, reagent-free method highly efficient for separating mixtures
2. Grinding: grinding into flakes with a size of 4–10 mm — the “flakes” that enter the processing line
3. Washing: removal of contaminants (soil, oils, labels) in industrial washers with hot water and neutral detergent
4. Drying: centrifuge + hot air drying to a moisture level < 0.1% — a requirement of the extrusion process
5. Extrusion and pelletizing: melted HDPE, filtered, and cut into homogeneous pellets — recycled raw material pellets ready for production
6. Characterization: MFI (melt flow index), density, and mechanical strength tests for classification by application grade
7. Reprocessing: recycled pellets mixed with virgin resin in controlled proportions → new tubes and compounds with certified performance

Techduto Recycling Program — two fronts, continuous result

Industrial Recycling (Post-Industrial)

In Techduto’s four manufacturing units, 100% of production waste — scraps, rejects, and out-of-spec tubes — are separated, ground, and reprocessed internally. Nothing goes to the landfill. The utilization rate is monitored as an environmental performance indicator per unit.

Post-Consumer Collection

Discarded HDPE pipes from construction sites, renovations, and facility decommissioning are collected through partnerships with recycling cooperatives, construction companies, and partner clients. The material is sorted, washed, and incorporated into the industrial flow — exiting as certified raw material.

Sources of post-consumer HDPE we accept:

• Corrugated and smooth tubes from deactivated facilities
• HDPE drums and barrels (post-use of non-hazardous products)
• Industrial HDPE packaging
• Post-industrial HDPE bags and films

Measurable Environmental Impact — real numbers

Each ton of recycled HDPE instead of virgin resin generates the following environmental benefits:

Source: UEM-PR (Maringá State University) and UNISC-RS (University of Santa Cruz do Sul) studies.

Scientific Proof — technical basis, not marketing

The technical feasibility of recycled HDPE in structural applications was proven by independent university research:

UEM-PR — Maringá State University

Analysis of mechanical and rheological properties of HDPE over up to 5 reprocessing cycles. Result: proven stability of tensile strength, elasticity modulus, and melt flow index. HDPE does not “degrade” with recycling — maintains its performance.

UNISC-RS — University of Santa Cruz do Sul

Study on the incorporation of post-consumer HDPE into blends with virgin resin for pipe production. Result: technical feasibility validated for up to 30% recycled content without compromising the final product’s properties.

These studies underpin Techduto’s compound formulation decisions — ensuring that choosing recycled material does not compromise performance.

Recycled Compounds 2025 — what you can request

In 2025, Techduto launched its line of high-performance recycled compounds. These are certified formulations with defined post-consumer HDPE content, developed based on UEM-PR and UNISC-RS studies.

• Controlled proportions of recycled HDPE validated in the laboratory — applications defined by testing, not estimation
• Origin traceability — documentation of the origin of the incorporated recycled material
• Technical documentation available for projects requiring proof of recycled content (ESG, bids, LEED/EDGE certifications)
• Product technical sheets with performance data and percentage of recycled content per batch

The 2025 compounds are Techduto’s next step towards products with increasing recycled content — with progressive targets for the coming years.

Applied Circular Economy — the complete cycle

The ideal circular economy model for HDPE completes the cycle entirely:

1. Extraction and production: oil → ethylene → virgin HDPE → pellets
2. Manufacturing: virgin + recycled pellets → corrugated HDPE Techduto pipes
3. Installation and use: 75–100 years of service life in infrastructure
4. Post-use collection: pipes removed from construction sites, renovations, decommissioning
5. Recycling: grinding → washing → pelletizing → certified recycled HDPE
6. Return to production: recycled pellets enter the next production line

With each recycling cycle, dependence on oil decreases. In a full circular economy scenario, a pipe installed today can become the raw material for another pipe in 75 years — keeping the material in use indefinitely and out of landfills forever.