Cast-film conversion of YS-W05 for BOPET begins with desiccant drying at a supply dew point of −40 °C and a pellet outlet temperature of 150–165 °C. The amorphous chip stock must not be dried above 170 °C because the pellets begin to crystallize rapidly at that threshold, which shifts the melting enthalpy and causes die-pressure instability on the cast line. Moisture content above 50 ppm at the extruder throat causes hydrolytic chain scission and reduces intrinsic viscosity during the first pass. The pellet is fed into a single-screw extruder with L/D of 30:1 to 36:1, a barrier screw section, and a screen changer fitted with 20–32 µm pleated polymer elements. Melt temperature measured at the flex-lip die is held within 270–285 °C. Residence time above 295 °C is limited to less than 15 min because acetaldehyde formation and gel counts accelerate beyond that boundary. The cast web is pinned to a chill roll at 20–40 °C to suppress crystallization and maintain low optical haze. Sequential biaxial orientation applies machine-direction draw ratios of 3.0:1 to 4.0:1 and transverse-direction draw ratios of 3.5:1 to 4.5:1. Heat-setting at 200–230 °C reduces free shrinkage to ≤2.0% at 150 °C when tested per ASTM D1204. The resulting films are slit or metallized for flexible food lidding, printed label facestock, capacitor-grade dielectric film, and barrier packaging laminations. Direct food-contact compliance follows FDA 21 CFR 177.1630(b) and EU Regulation 10/2011; overall migration with 10% ethanol or 3% acetic acid food simulants must not exceed 10 mg/dm². The film haze is determined per ASTM D1003 and normally remains below 2.0% when the chill roll surface finish and filtered cleanroom environment are maintained. A known incompatibility exists with amine-functional slip or antistatic masterbatch systems, which can accelerate hydrolysis at the BOPET heat-setting stage.

On high-output APET sheet lines, YS-W05 is converted directly into clear sheet for plug-assisted thermoforming of refrigerated food trays, bakery clamshells, and fresh produce punnets. Drying is carried out at 150–165 °C for 4–6 h in a desiccant-hopper dryer with a dew point below −35 °C. Extruder barrel zones are profiled from 240 °C at the feed section to 270–280 °C at the adapter, with melt temperature at the polishing rolls held near 265 °C. The melt is filtered through 40–60 µm screen packs and delivered through a coat-hanger die to a vertical three-roll stack. Roll temperatures are set between 30 °C and 60 °C, producing a sheet thickness tolerance of ±0.05 mm across widths of 600–1,200 mm. During form station entry, the sheet surface reaches 120–150 °C. Plug-assisted thermoforming with a cavity depth-to-width draw ratio up to 2:1 and a 0.8–1.2 s dwell period produces trays with sidewall haze below 3% per ASTM D1003. Food-contact testing under FDA 21 CFR 177.1630 and EU Regulation 10/2011 covers total non-volatile residue; the specific migration limit for antimony is 0.04 mg/kg in Regulation 10/2011. The sheet is slit into rolls for clamshell containers, cookie trays, chocolate inserts, and fruit punnets. Edge trim regrind is fed back into the extrusion stream at up to 35 wt%; above that level, melt homogeneity is disrupted and gel levels become visible. If ambient relative humidity exceeds 60%, the regrind stream must be dried in a second-stage hopper or isolated from moist air to prevent hydrolysis defects.

What Limits Thin-Wall Preform Lightness in Amorphous PET Injection Molding?

For ISBM conversion of YS-W05 into non-carbonated cosmetic jars, vitamin bottles, and small food jars, the critical inlet variable is intrinsic viscosity determined per ISO 1628-5. If the measured IV is below 0.72 dL/g, thin-wall preforms below 2.0 g are not recommended because the melt strength at blow temperatures cannot sustain hoop draw ratios beyond 2.8:1 without sidewall thinning. When the IV is within the typical sheet-grade window of 0.72–0.80 dL/g, YS-W05 is injection-molded at melt temperatures of 270–290 °C, with a hot runner temperature of 280–295 °C and a mold temperature of 8–12 °C. The cycle time is 20–30 s for a 25–50 g preform, depending on wall thickness. Reheat-stretch blow molding is carried out at preform surface temperatures of 100–130 °C, with axial stretch ratios of 2.0:1 to 2.8:1 and hoop stretch ratios of 2.8:1 to 3.5:1. Acetaldehyde in the finished preform is measured per ASTM F2013 and ideally kept below 10 ppm for taste-sensitive applications. Food-contact status follows FDA 21 CFR 177.1630 and EU Regulation 10/2011; the same antimony specific migration limit of 0.04 mg/kg applies. This ISBM window should not be extended to carbonated beverage bottles above 1.5 L, because published data for this specific configuration is limited and the burst pressure requirement is not demonstrated for low-IV amorphous chip stock without solid-state polycondensation.

When Amorphous Chip Stock Replaces Dried Crystalline Pellet in Oriented Strapping Lines

On industrial strapping lines that normally run crystallized PET feedstock, YS-W05 is processed as an alternative input when the extruder is equipped with a gear pump and static mixer. The feed is dried to ≤50 ppm moisture and extruded at 280–295 °C through a flat or profile die. The molten ribbon enters a quench water bath at 30–50 °C; quench residence time must be sufficient to develop a fine amorphous structure that orients uniformly in the next step. Orientation is performed at 80–120 °C with draw ratios between 5:1 and 8:1. Relaxation of 5–10% after stretching reduces split tendency during wind cycling. The oriented strap develops a tensile strength above 500 MPa and an elongation at break between 12% and 20% when tested per ASTM D638-14. The target strap width is 9–32 mm with thickness of 0.6–1.3 mm. End products include pallet strapping, bundle strapping for paper rolls, and baling straps for textile and cotton compression. This non-food industrial route is evaluated under RoHS 2011/65/EU Annex II, with lead below 1000 ppm and cadmium below 100 ppm. The converter should avoid blending YS-W05 with polypropylene or polyethylene carry-over above 2 wt%, because incompatible domain size leads to transverse fracture under impact load at low warehouse temperatures.

YS-W05 is also extruded into sheet for print-receptive graphic display, glazing, and electronics carrier trays, where haze and thickness control are tighter than in food-only sheet. Drying at 150–165 °C to moisture below 50 ppm is followed by extrusion through a polished roll stack at 30–50 °C. Sheet for glazing is produced at 0.5–3.0 mm thickness with a total luminous transmittance of ≥88% per ASTM D1003 and a haze value below 1.5%. Print adhesion is governed by surface energy after corona treatment; a minimum dyne level of 40 mN/m is required prior to lithographic or flexographic printing. The compliance matrix below applies to display and electronics carrier applications.

The formed trays and display panels are converted by die-cutting and heat-bending at 100–130 °C; this is below the crystalline melting range and avoids stress whitening. End products include point-of-sale display boxes, shelf strips, glazing sheets, and protective carrier trays for electronic components. The converter must control post-extrusion cooling because internal stress remains visible as optical wave patterns when sheet is heated above 90 °C without a relaxation step.

rPET Blending Windows in Co-Rotating Twin-Screw Extruders

For recyclers and compounders, YS-W05 acts as a viscosity-stabilizing feedstock when blended with washed post-consumer or post-industrial PET flake. A co-rotating twin-screw extruder with L/D of 36:1 to 44:1 is configured with at least one devolatilization vacuum port operating at −0.08 MPa to −0.095 MPa. The blend is dried to moisture below 200 ppm before processing. The melt temperature is held at 270–285 °C, and screw speed is kept within 250–450 rpm to limit shear-induced temperature rise. YS-W05 addition rates of 20–50 wt% compensate for the lower intrinsic viscosity of recycled flake; below 20 wt%, the melt frequently fails during downstream drawing. Flake particle size above 12 mm creates inconsistent feeding and reduces dispersion. The compounded extrudate is pelletized and later converted into non-food strapping, monofilament, or thick sheet. This recycled stream is not automatically cleared for food-contact use; validation follows the appropriate national or EFSA recycling process authorization for post-consumer PET if food-grade output is required. For non-food routes, documentation is maintained against REACH and RoHS 2011/65/EU Annex II. The practical boundary is that flake purity below 98 wt% PET, with polyolefin contamination above 1 wt%, causes visible melt fracture and delamination in the final sheet.