Continuous staple fibre lines processing YS-W100R are not limited by melt temperature alone; the specific boundary conditions are pellet moisture, intrinsic viscosity distribution, and the pressure-rise profile across the melt filtration pack. Pellets are pre-dried in a desiccant-wheel dryer with a dew point no higher than -40 °C at 160 °C for 6 h. Residual moisture is determined by ISO 15512:2016 and must be held below 50 ppm before the extruder throat; wet feed causes hydrolytic chain scission in the first barrel zones and an intrinsic viscosity loss above 0.03 dL/g. Intrinsic viscosity is measured on the incoming pellet and on spun fibre by ASTM D4603-18 in 60:40 phenol/1,1,2,2-tetrachloroethane at 25 °C. If pellet IV falls below 0.62 dL/g, filament tenacity drops below acceptable values for standard 0.9–22 dtex fibre; if pellet IV exceeds 0.80 dL/g, melt pressure rises and requires a higher extrusion temperature that accelerates thermal degradation. Production-scale spinning equipment for YS-W100R typically uses a single-screw extruder with a 36:1 L/D barrier screw and compression ratio of 2.8:1, a gear melt pump, and a dual-stage vacuum vent at -0.08 MPa. The melt pump inlet is maintained at 282–290 °C, while the spinning beam is held at 285–292 °C. Quench air is controlled at 18–22 °C with crossflow velocity 0.4–0.6 m/s. The main production bottleneck is screen-pack pressure rise: a rise of more than 25% within 4 h or an absolute pressure above 120 bar indicates non-PET contamination, gel formation, or degraded flake; the melt filter is typically 40 µm. Batch-to-batch IV variation is managed by pre-blending incoming lots to keep the standard deviation below 0.02 dL/g; higher variance produces fibre denier drift and increases spinning breaks. PVC contamination in the recycled feed at levels above 50 ppm is unacceptable because it decomposes at PET processing temperatures and generates hydrochloric acid, which accelerates chain scission and causes corrosion in downstream draw stands. Polyolefin contamination above 30 ppm produces gel spots and draw-line breaks. These operational limits are derived from standard rPET fibre line practice; published data for this specific YS-W100R configuration is limited, so incoming contamination and IV must be verified lot by lot.

Where Extruded PET Strapping Demands Consistent Melt Pressure Across 120 mm Barrier Screws

Extruded polyester strapping made from YS-W100R is processed under conditions that are more draw-critical than fibre: the film is quenched, oriented, and slit, so local melt-pressure variation becomes thickness bands and tensile failure at the draw gap. For high-tenacity strapping with a target tensile strength above 400 MPa under ASTM D3954, the incoming resin IV should be at least 0.80 dL/g. Extrusion lines are typically built around a 120 mm single-screw extruder with 30:1 L/D, a melt gear pump, and a flexible-lip flat die. Melt temperature at the die is held between 270 °C and 285 °C; die pressure is controlled between 50 bar and 80 bar. Pressure fluctuation greater than ±1.5% is visible as transverse gauge bands after orientation and is rejected. The quench bath is kept at 40–55 °C, and the orientation zone is heated to 95–115 °C with a draw ratio of 5.0:1 to 6.0:1. Final strap width is generally 12–25 mm and thickness 0.6–1.2 mm. Moisture must remain below 50 ppm by ISO 15512:2016; a higher level produces hydrolytic IV loss, lower tensile strength, and increased break frequency between the first and second draw rolls. If YS-W100R has an IV below 0.75 dL/g, the draw ratio is reduced to 4.0:1 or lower, and the grade is restricted to strapping with tensile strength below 300 MPa. PVC contamination above 50 ppm is also critical in strapping: it decomposes into hydrochloric acid and creates black specks, surface roughness, and acid-catalysed polymer degradation. Polyolefin contamination above 30 ppm produces gel particles that disturb the melt curtain and cause edge fibrillation after slitting. Process records show that most strapping line stops are caused by filter pack blockage rather than by melt-temperature variation; 20–40 µm screen packs are used, and pack replacement is scheduled at a pressure rise of 40 bar above the clean-pack baseline.

For rPET sheet extrusion from YS-W100R, the extruder configuration includes vacuum devolatilisation rather than simple pre-drying alone, because post-consumer feedstock can retain volatile residues after washing and solid-state processing. Sheet lines use a corotating twin-screw extruder or a ventilated single-screw extruder with an open vent and vacuum level of at least -0.08 MPa. Melt temperature at the sheet die is kept between 270 °C and 285 °C, and the polished chill-roll stack is controlled at 15–25 °C. Sheet thickness is normally 0.4–1.5 mm for trays, clamshells, and industrial packaging. Food-contact use imposes a legal boundary that is not resolved by extrusion temperature: in the EU, the recycled PET process must have an approval under EU Regulation 2022/1616, and the finished article must comply with overall migration limits in EU Regulation 10/2011 Annex III. In the US, a valid FDA Letter of No Objection for the specific recycling process is required, with the base polymer assessed under 21 CFR 177.1630. Without these approvals, monolayer sheet from YS-W100R is restricted to non-food trays and industrial packaging. A three-layer A/B/A sheet structure with virgin PET cap layers is commonly used for food-contact trays when the recycled core is not authorised for direct food contact; the cap-layer thickness is typically not less than 25–40 µm per side, but final compliance depends on barrier modelling and migration testing. Production control problems in sheet extrusion are dominated by roll wrap and haze: melt temperatures above 285 °C cause sticking to the chill roll, and roll temperatures above 25 °C increase spherulitic crystallisation, raising haze. Inline optical inspection is performed with a 0/45° spectrophotometer; colour difference ΔE* against the approved batch above 2.0 is rejected for cosmetic sheet. Acetaldehyde in sheet is measured by headspace gas chromatography and is controlled below 3–10 mg/kg depending on package size and food contact time. Published data for this specific YS-W100R configuration is limited, so migration and sensory testing must be performed on the final article rather than assumed from pellet specifications.

What Preforms and Container Reheat Profiles Reveal About Copolymer Content in YS-W100R?

Injection stretch blow moulding of preforms from YS-W100R introduces an additional control point that is absent in sheet or fibre: infrared reheat behaviour. Preform injection is carried out on a reciprocating-screw machine with an accumulator or shut-off nozzle, barrel temperature zones from 265 °C to 285 °C, hot-runner temperature 270–285 °C, and a cold mould at 6–12 °C. Pellets are dried at 170 °C for 5 h in a desiccant dryer to a residual moisture below 35 ppm; this tighter limit is used because acetaldehyde specifications for beverage containers are stricter than for sheet. Acetaldehyde in ground preforms is measured by headspace gas chromatography and is typically kept below 10 mg/kg for water-contact containers, while sensitive mineral water grades may require below 5 mg/kg. The reheat station uses quartz IR lamps to raise the preform surface to 100–110 °C before stretch-blow. If YS-W100R contains post-consumer copolyester, polyolefin residues, or variable comonomer content, the DSC heating curve measured under ISO 11357-3 shifts the melting peak and cold crystallisation temperature; this alters infrared absorption and causes off-centre gates, uneven side-wall thickness, or blowouts at the same lamp settings. A melt-peak shift larger than 2 °C from the validated setpoint is an early warning for feedstock change. Process equipment failures include gate blush and preform streaks when screw recovery time extends beyond 8 s, indicating excessive melt viscosity or poor melting uniformity. Shooting-pot injection pressure above 120 bar should not be corrected simply by raising barrel temperature above 290 °C, because this accelerates thermal degradation and increases acetaldehyde regeneration. The IV of the preform is checked after injection to measure process-induced degradation; a drop greater than 0.02 dL/g between dried pellet and preform usually indicates moisture leakage or a worn check ring. Published data for this specific configuration of YS-W100R is limited; these limits are standard control points observed on production-scale rPET preform lines.

Injection moulding of non-structural technical parts from YS-W100R generally requires crystallisation modification and impact modification because unmodified recycled PET is notch-sensitive and slow to crystallise in a cold mould. For technical parts, the resin is dried at 150 °C for 4 h to a moisture level below 50 ppm. Melt temperature is set from 260 °C to 280 °C, and the mould is maintained at 100–130 °C. A mould temperature below 100 °C produces largely amorphous parts with lower heat deflection and greater post-mould shrinkage; a mould temperature above 130 °C increases cycle time and can cause ejection deformation. Nucleating agents such as fine talc at 0.3–0.8 wt% or sodium ionomers at 0.2–0.5 wt% raise crystallisation rate and improve surface stability. Impact modification with an ethylene-butyl acrylate-glycidyl methacrylate terpolymer at 5–15 wt% raises Charpy notched impact from below 3 kJ/m² to above 8 kJ/m² measured under ISO 179-1/1eA. Tensile modulus and strength are measured on injection-moulded plaques under ISO 527-2; unreinforced rPET modulus is typically 2.0–2.5 GPa, but published data for this specific recycled lot is limited. The production bottleneck is feeding: recycled pellets can have lower bulk density than virgin pellets, so a crammer feeder or vented barrel with at least 24:1 L/D is needed to maintain shot-to-shot consistency. Variability in pellet size creates screw recovery-time drift; recovery time outside ±0.5 s of the validated window is an early warning of feed-bridging or contamination.

When Recycled Feedstock Replaces 30% Virgin PET in Glass-Fibre-Reinforced Compounds

Glass-fibre-reinforced compounds using YS-W100R are prepared on corotating twin-screw extruders with 40:1 L/D, side-feeding of glass fibre after the melt seal, and vacuum venting before discharge. The recycled resin is pre-dried at 150 °C for 4 h to below 50 ppm moisture; wet feed causes an IV loss greater than 0.04 dL/g and generates volatiles that overload the vacuum vent. Glass fibre at 30 wt% is introduced through a side stuffer, screw speed is maintained at 300–500 rpm, and melt temperature is kept between 280 °C and 295 °C. The higher temperature window compared with unfilled rPET is needed for fibre wet-out but increases the risk of thermal and hydrolytic degradation, so residence time is controlled below 90 s. Tensile strength of a well-compounded virgin PET-GF30 measured under ISO 527-2 normally falls between 140 MPa and 160 MPa, and flexural modulus under ISO 178 between 9 GPa and 10 GPa; these values are validation targets for YS-W100R compounds, not guaranteed properties, because published data for this exact feedstock is limited. Impact-modified rPET-GF30 grades are additionally tested under ISO 179-1/1eA and ISO 6603-2 for falling-weight puncture behaviour. The central processing conflict is fibre attrition versus dispersion: an aggressive screw profile reduces fibre length and lowers notched impact strength, while an overly gentle screw profile leaves fibre bundles and produces surface roughness. A medium-shear screw layout with two neutral mixing blocks before the side feeder is specified. Residual polyolefin contamination in the recycled feed above 5 wt% can cause interfacial delamination and must be controlled by flake sorting, not by compounding conditions alone. Incompatibility with amine-based additives should be evaluated case by case because they can accelerate transesterification in polyester matrices, although published data for YS-W100R in this additive system is limited.

Monofilament Spinning, Filtration Bypass, and Diameter Variance

Monofilament extrusion from YS-W100R covers brush bristles, zip ties, filter fabrics, and geotextile monofilaments. The line configuration uses a single-screw extruder with 30:1 L/D, a melt pump, and a screen changer with 20–40 µm filtration media. Melt temperature is set at 275–290 °C, and the extrudate is quenched in a water bath at 25–40 °C. Two-stage orientation in hot-air ovens or hot-water baths applies a total draw ratio of 3.0:1 to 4.5:1, producing final diameters from 0.15 mm to 0.80 mm. Filtration bypass is the leading cause of diameter variance: if the screen-pack pressure drop exceeds 80 bar or rises by 30% within 2 h, the pack is changed before gel particles reach the die. Diameter coefficient of variation above 2% across a 24 h run indicates gel passage, melt-temperature stratification, or insufficient static mixing. Incoming IV should be between 0.70 dL/g and 0.80 dL/g for general monofilament; IV below 0.65 dL/g reduces knot strength and flexural fatigue, while IV above 0.85 dL/g increases melt pressure and denier variation unless the melt pump is re-trimmed. Tensile properties are tested on conditioned filament according to ISO 527-1 or ISO 2062 for yarns; elongation at break is typically 15–30% depending on draw ratio. Moisture control follows the same requirement as other PET extrusion: below 50 ppm by ISO 15512:2016. For geotextile monofilaments that will be exposed to alkaline soil water, long-term alkali resistance testing under ISO 12960 is advised because recycled PET may show localised surface degradation if incompletely washed caustic residues remain.