In carbonated soft drink (CSD) container conversion, YS-Y01 resin is dried at 160–180 °C for 4–6 h in a desiccant-wheel dryer to reach a pellet moisture content not exceeding 30 ppm as measured by Karl Fischer titration according to ISO 15512:2019; where silos have been exposed to relative humidity above 60%, dry-air conveying or extended drying is applied because residual moisture produces hydrolytic intrinsic-viscosity loss during plasticising, which appears on the production floor as inconsistent preform weight and lower top-load resistance. The delivered lot is checked for intrinsic viscosity against the supplier certificate of analysis using ISO 1628-1:2021 before drying. The dried YS-Y01 is fed to a reciprocating injection unit with screw L/D 20:1–24:1 and compression ratio 2.2:1–3.0:1, with barrel setpoints held between 270 °C and 290 °C. The hot-runner manifold and valve-gate drops are balanced to keep cavity-to-cavity fill variance below 1.0% by shot weight; wider variance alters sidewall thickness distribution and lowers burst-pressure reproducibility. The preform mould is maintained at 8–12 °C water circulation to quench the melt into an amorphous state, after which preforms are reheated to 90–110 °C surface temperature and stretched in a two-stage reheat blow moulder with axial stretch rod and pre-blow timing adjusted to prevent pearlescence and stress whitening. Formulation addition is 100 wt% YS-Y01 for monolayer CSD preforms; where food-contact post-consumer rPET is cleared through a US FDA letter of no objection or an equivalent national authorisation, rPET may replace up to 25 wt% of YS-Y01, but higher rPET content increases gel-particle incidence and broadens molecular-weight distribution, which is observed as greater carbon dioxide loss through the sidewall. Regulatory compliance is anchored to FDA 21 CFR 177.1630 and Commission Regulation (EU) No 10/2011, with overall migration not exceeding 10 mg/dm² and specific migration limits for terephthalic acid at 7.5 mg/kg, ethylene glycol at 30 mg/kg, and antimony at 0.04 mg/kg. Downstream terminal products are 330 mL, 500 mL, 1.25 L, and 2.0 L carbonated soft drink bottles with closure threads from 28 mm to 38 mm; drop impact is tested per ASTM D2463-15, and carbon dioxide retention is measured by ASTM F1115-95.

What Acetaldehyde Generation Limit Separates Still Water Preform Molding From Carbonated Beverage Processing?

The limiting variable in still water preform production is residual acetaldehyde, not carbon dioxide retention. YS-Y01 is processed at the lower end of the injection temperature window—270–280 °C—because acetaldehyde generation follows thermal degradation kinetics and rises sharply when barrel residence time exceeds 5 min or hot-runner surface temperature exceeds 280 °C. Preform acetaldehyde is quantified by headspace gas chromatography according to ASTM F2013-10; taste-sensitive water fillers commonly require not more than 2 µg/L acetaldehyde in the finished bottle after migration, although published sensory thresholds range from 1 µg/L to 10 µg/L. The addition ratio is 100 wt% YS-Y01. If a converter runs high-cavitation tools with long melt residence and fails the acetaldehyde specification, an acetaldehyde-control masterbatch at 0.2–0.5 wt% may be introduced, but this changes preform haze and must be revalidated under ASTM D1003-21. Downstream injection uses high-cavitation presses of 48–96 cavities with balanced hot runners; cavity-to-cavity fill imbalance above 1.5% produces thick-walled preforms that overheat during reheating and generate additional acetaldehyde. The preforms are injection moulded at 270–280 °C melt temperature, quenched in 8–12 °C moulds, and blow-moulded on reheat stretch equipment. Regulatory compliance is under FDA 21 CFR 177.1630 and (EU) No 10/2011. Terminal products are still water bottles from 200 mL to 2 L; bottle sidewall haze is measured by ASTM D1003-21, and final acetaldehyde is confirmed by ASTM F2013-10 before release.

Because edible oil containers are evaluated under fatty-food simulant D2 and are not subjected to carbonation pressure, the critical control points shift from burst resistance to wall-thickness distribution, oxygen ingress, and migration under oily contact. YS-Y01 is used at 100 wt% for direct food contact; post-consumer recyclate is omitted unless the specific rPET source holds a US FDA letter of no objection or EU recycled-plastics authorisation under Commission Regulation (EC) No 282/2008. Clarified oil grades packaged in transparent containers may use a UV-absorber masterbatch at 0.3–1.0 wt%, with the balance YS-Y01, because lipid oxidation is accelerated by ultraviolet wavelengths below 390 nm; if the masterbatch affects transparency, light transmission is measured by ASTM D1003-21. Preforms for edible oil containers are injection moulded with thicker sidewalls and a heavier finish than water bottles; injection velocity is reduced to limit shear-induced crystallinity, and melt temperature is held at 270–285 °C. After reheating and stretch blow moulding, the container is tested for oxygen transmission rate by ASTM F1307-14; a drop impact test by ASTM D2463-15 verifies that the thickened wall retains toughness under cold-chain distribution. Regulatory migration testing follows (EU) No 10/2011 with fatty-food simulant D2 at 40 °C for 10 days and FDA 21 CFR 177.1630 conditions of use; the specific migration limit for terephthalic acid is 7.5 mg/kg, and overall migration must not exceed 10 mg/dm². Terminal products are 500 mL, 1 L, 2 L, and 5 L edible oil bottles for soybean, rapeseed, sunflower, and blended vegetable oils.

When Hot-Fill Stability Demands Crystallinity Above 25%, Mold Temperature Control Replaces Ambient Blowing Practice

Heat-set blow moulding differs from ambient cold-mould blowing in that the blow mould surface is held at 120–150 °C rather than 8–12 °C. YS-Y01 may be processed at 100 wt% for hot-fill applications only when the target fill temperature does not exceed 75 °C; for fill temperatures of 85 °C or higher, published data for YS-Y01 is limited, and the converter must validate sidewall crystallinity and volume shrinkage under the specific fill profile before commercial use. The heat-set process requires preform surface temperature of 100–110 °C, blow pressure of 25–38 bar, and blow mould residence time sufficient to induce crystallinity above 25% as measured by differential scanning calorimetry according to ISO 11357-3:2018; lower crystallinity produces volume shrinkage that commonly exceeds 1.5% after filling. The thermal stability of the blown container is evaluated by filling at the target temperature and measuring dimensional change; because no universal ISO method applies to hot-fill volume stability in blown PET containers, brand-specific specifications predominate. Preform injection for heat-set containers is run at the lower end of the melt temperature window, 270–280 °C, to limit premature crystallinity, and the preform design is adjusted to shift material away from the neck and base regions where shrinkage is greatest. Regulatory compliance is anchored to FDA 21 CFR 177.1630 and (EU) No 10/2011; antimony migration must not exceed 0.04 mg/kg. Terminal products are 250 mL–1.5 L hot-fill bottles for juices, teas, and sports drinks.

Although APET sheet extrusion shares the same drying and moisture limits as preform injection, the downstream thermoforming process imposes additional control over sheet crystallinity, thickness uniformity, and melt residence time. YS-Y01 is dried to ≤ 30 ppm moisture as measured by ISO 15512:2019 and extruded through a vacuum-vented single-screw or co-rotating twin-screw line with L/D 30:1–34:1; barrel setpoints are held at 270–285 °C, and a melt pump delivers consistent head pressure to a coat-hanger die. Polished chill rolls maintained at 25–40 °C solidify the web before thickness gauging and roll winding; edge trim is reground and re-fed at up to 30 wt% when the regrind is controlled for moisture, gel count, and intrinsic-viscosity loss. Direct food-contact sheet is produced with 100 wt% YS-Y01; in-plant regrind may replace part of the virgin feed within the 30 wt% boundary, provided the final sheet complies with FDA 21 CFR 177.1630 and (EU) No 10/2011 overall migration not exceeding 10 mg/dm². Amine-based processing aids are not introduced because they catalyse ester cleavage and lower molecular weight. Thermoforming is performed at sheet surface temperatures of 100–160 °C on roll-fed or sheet-fed machines; plug assist and cavity vacuum are adjusted to avoid corner thinning below 50% of nominal sheet thickness. Terminal products include fresh produce trays, bakery clamshells, portion cups, and food-service lids with starting sheet thickness from 0.2 mm to 1.5 mm.

Optimising Strapping Tensile Retention Through Draw Ratio and Annealing Temperature

On strapping extrusion lines, YS-Y01 is processed after drying to ≤ 30 ppm moisture to prevent hydrolytic degradation during melt processing. The resin is extruded through a single-screw line with L/D 30:1 and melt setpoints of 280–290 °C; the cast strap is quenched in a water bath to a largely amorphous state, then drawn in a hot-air or hot-water oven at a draw ratio of 3.5:1–5.5:1 and annealed at 180–220 °C. Higher draw ratio raises tensile strength but increases fibrillation; lower annealing temperature leaves residual free shrinkage that can loosen on a pallet. The formulation is 85–100 wt% YS-Y01; cleaned post-consumer rPET may be added up to 15 wt% if weld strength and break elongation remain within ASTM D3950-18. Outdoor-grade strapping uses a UV masterbatch at 0.5–1.5 wt%, with YS-Y01 as the balance. Break strength and joined-strap strength are measured according to ASTM D3950-18, and tensile elongation at break is determined by ASTM D638-14. Terminal products are 10–19 mm wide polyester strapping for pallet unitisation, bundle tying, and heavy package closure.

Cosmetic Bottle Moulding Requires Validation Against Ethanol-Induced Environmental Stress Cracking

Cosmetic bottles produced from YS-Y01 are tested for environmental stress cracking because personal-care formulations often contain ethanol, surfactants, and essential oils that can accelerate crazing in amorphous PET sidewalls. The resin is dried to ≤ 30 ppm moisture and injection-moulded into thick-walled preforms at melt temperature 270–280 °C; preforms are then blow-moulded in one-stage or two-stage ISBM equipment with mould surface temperature 8–12 °C to preserve optical clarity. Formulation is 100 wt% YS-Y01 for transparent containers; colour masterbatch is introduced at 0.5–2.0 wt% when tinted or opaque packages are required, and regrind should not exceed 20 wt% to avoid surface haze and intrinsic-viscosity reduction. Stress-cracking compatibility is evaluated by exposing blow-moulded bottles to the target formulation at 40 °C for 7 days, followed by visual inspection and tensile property retention under ASTM D638-14; published data for specific fragrance and essential-oil combinations with YS-Y01 is limited, so validation is mandatory before filling. High-terpene essential-oil formulations are not assumed compatible; a full stress-crack matrix is required because the amorphous PET wall can craze under concentrated terpene contact. Regulatory compliance for cosmetic packaging includes EU Regulation (EC) No 1223/2009 for the finished cosmetic product and 94/62/EC for packaging heavy metals where applicable; if the bottle is used for food-adjacent gift sets, compliance with FDA 21 CFR 177.1630 and (EU) No 10/2011 is verified separately. Terminal products are 30–500 mL bottles for toners, serums, lotions, and hair-care formulations.