Within potable water contact rotational moulding, Braskem PROXESS 3310 is dry-blended at 98.5–99.4 wt% resin with 0.1–0.3 wt% hindered phenolic antioxidant, 0.2–0.6 wt% high-molecular-weight HALS, 0.05–0.15 wt% calcium stearate acid scavenger, and 0.3–1.0 wt% food-contact-compliant pigment masterbatch; total additive loading is kept below 1.5 phr because higher concentrations depress long-term hydrostatic creep resistance in vertical tank walls. Incoming powder is checked according to ISO 1133-1:2022 at 190°C/2.16 kg; lot-to-lot shifts outside the certificate of analysis are compensated by oven residence time adjustment of 2–4 min, not by raising oven temperature. The powder is ground to a 35-mesh (500 µm) cut with 90–95 wt% passing 60-mesh and fines below 10 wt% at 200-mesh; powder temperature during attrition pulverizing is held below 45°C, since fines soften and fuse onto rotor tips when the mill gap falls below 0.2 mm, causing batch-to-batch particle-size drift. The governing compliance framework includes NSF/ANSI/CAN 61, AS/NZS 4020:2018, FDA 21 CFR 177.1520, and Regulation (EU) 10/2011; finished plaques are tested on a surface-to-volume ratio representing the tank's maximum rated fill volume rather than on a lower-exposure flat coupon. The moulding cycle uses biaxial primary rotation of 6–10 min⁻¹, secondary rotation of 1.5–2.5 min⁻¹, oven air temperature of 280–310°C, and cook termination when internal air temperature reaches 190–205°C. The cook termination band is held at ±5°C; internal air above 210°C initiates oxidation embrittlement, while internal air below 185°C leaves unmelted powder at the parting line. Forced-air cooling for 8–12 min followed by water-mist cooling for 3–6 min is standard; the part is not exposed to water mist above 120°C surface temperature because rapid quench sets up differential crystallization and causes stress whitening at seams. End products are 500–25,000 L vertical water storage tanks, truck-mounted potable water tanks, and rainwater cisterns with nominal wall thickness from 4 mm to 12 mm.

Agrochemical Tank ESCR and Carbon Black Loading

Formulation for agrochemical containment under Braskem PROXESS 3310 uses 97.0–98.5 wt% resin, 1.5–2.5 wt% UV-stabilized carbon black masterbatch, 0.15–0.35 wt% processing antioxidant, 0.05–0.15 wt% acid scavenger, and, if the stored fluid contains more than 5 vol% ester or aromatic solvent, 1.0–2.0 wt% fluoropolymer processing aid to reduce microvoid coalescence at internal corners; published data for this specific configuration is limited. The powder cut is shifted coarser to a 30-mesh average (600 µm) with fines constrained below 8 wt% at 200-mesh to maintain fill-line flow when the mould arm length exceeds 4 m. Applicable standards are ASTM D1998-21 for polyethylene upright storage tanks, ISO 179-1:2010 notched Charpy impact at 23°C and -20°C, ASTM D1693-15 environmental stress crack resistance Condition B in 10% Igepal CO-630, and UN 1H1 certification where the tank is used for legally classified dangerous goods. Moulders run a reduced oven temperature of 270–290°C and terminate cook at an internal air temperature of 180–195°C; if peak internal air is allowed to exceed 210°C, oxidation embrittlement at the inner wall reduces ESCR below the acceptance threshold specified in ASTM D1998-21. Cooling is sequenced as 10–14 min forced air, 2–4 min intermittent water mister, and 20–30 min ambient stabilization before demoulding. End products include horizontal agrochemical transport tanks, crop-sprayer tanks, and fertilizer storage vessels with wall thickness from 5 mm to 15 mm and hydrothermal endurance tested at 60°C for 500 h.

For marine flotation components, Braskem PROXESS 3310 is compounded with 2.0–3.0 wt% carbon black masterbatch, 0.3–0.6 wt% HALS, 0.1–0.3 wt% primary antioxidant, and, for foam-filled parts, 0.5–1.0 wt% azodicarbonamide chemical blowing agent whose decomposition onset around 190–205°C overlaps the resin melt range; the mould cavity is therefore charged to 50–70% of its volume to allow foam core expansion at the centre while the outer wall remains solid. The marine segment requires ISO 4892-3:2016 accelerated weathering under UV-A 340 lamps for 2000–3000 h, ISO 179-1:2010 notched impact at -30°C, and REACH Annex XVII restrictions on polycyclic aromatic hydrocarbons in the carbon black masterbatch. The rotomoulding cycle uses primary rotation at 8–12 min⁻¹, secondary rotation at 2–3 min⁻¹, oven air temperature 290–320°C, and a short internal air plateau of 175–190°C; internal air excursions above 200°C lead to over-expansion of the blowing agent, producing parting-line blowholes and skin delamination. Cooling starts with 8–10 min forced air and proceeds to water mist at 15–20°C until the part surface falls below 70°C; demoulding above 80°C causes permanent compression set at foam ribs, while cooling below 45°C before release can leave external sink marks. End products are encapsulated dock floats, navigation buoys, and modular pontoon floats with outer wall thickness between 4 mm and 8 mm and foam core density of 150–300 kg/m³.

What Processing Window Prevents Surface Defects in Playground Components?

Braskem PROXESS 3310 enters the playground and recreational component segment as a dry-blend of 98.5–99.5 wt% base resin, 0.3–0.8 wt% non-phthalate organic pigment masterbatch, 0.2–0.5 wt% HALS, and 0.05–0.15 wt% internal mold release; the pigment masterbatch is selected to meet EN 71-3:2019+A1:2021 migration limits for nineteen elements and ASTM F963-23 soluble heavy metal requirements, with the release formulation tested on the actual moulded surface texture rather than on a polished plaque. The powder particle-size distribution is held at 35-mesh (500 µm) with no more than 12 wt% retained on 60-mesh to reproduce fine-grained texture on cast aluminum moulds of 8–12 mm wall thickness. Moulders set oven temperature at 275–300°C, primary rotation at 6–9 min⁻¹, and secondary rotation at 1.5–2.5 min⁻¹; cook termination occurs at internal air temperature 185–200°C, because higher internal air produces low-molecular-weight surface material that creates gloss variation on slide walls and ladder rungs. Post-mould cooling is forced air for 10–15 min with mould ends blocked to prevent warpage in tubes and slide enclosures; water-spray cooling is limited to short intermittent bursts to avoid sink marks at boss attachments and handrail sockets. End products are rotomoulded slides, climbing tunnels, pedal cars, and self-supporting play panels with wall thickness from 4 mm to 10 mm.

In industrial bulk handling, Braskem PROXESS 3310 is formulated with a minimum 98.0 wt% resin, 1.0–2.0 wt% mineral-filled or carbon black masterbatch for flexural stiffness, 0.1–0.3 wt% primary antioxidant, and 0.05–0.15 wt% calcium stearate acid scavenger; the mineral filler addition is restricted to 2.0 wt% because higher loadings lower ESCR below the threshold required for pallet boxes operated in cold rooms at -20°C. The compliance framework for this segment rests on ISO 179-1:2010 notched impact at -20°C, ASTM D1693-15 ESCR Condition C in 100% Igepal CO-630, and FDA 21 CFR 177.1520 where reusable totes contact dry foodstuffs. Processing uses a cast aluminum mould of 10–14 mm wall thickness, a biaxial ratio of 3.5:1.0, oven temperature 280–310°C, and a cook time of 28–38 min for a 1000 L container and 18–24 min for a 300 L box; shorter cycles produce undercooked inner-wall pinholes at rib intersections, while longer cycles increase drop-impact but degrade corner straightness due to thermal expansion differences across the mould flange. Demoulding is performed after the part surface temperature falls below 55°C; forced ejection above that temperature causes corner warpage on thin floor ribs and can set residual stresses that later crack under stacking load. End products are 300–1500 L bulk bins, pallet boxes, insulated fish tubs, and modular hoppers with wall thickness from 5 mm to 14 mm.

When Rotomoulded Automotive Fluid Reservoirs Require Low-Temperature Impact

Braskem PROXESS 3310 is used for non-fuel automotive fluid reservoirs when the formulation includes 97.5–98.9 wt% resin, 0.5–1.5 wt% HALS/UV masterbatch, 0.2–0.5 wt% antioxidant, and 0.2–0.5 wt% processing stabilizer; for windshield washer and urea tanks, the inner wall is subjected to hydrolysis resistance screening at 60°C for 1000 h in 50% glycol solution, and published data for this specific configuration is limited. Compliance is anchored to ISO 179-1:2010 Charpy notched impact at -30°C, ISO 75-2:2013 heat deflection temperature at 0.45 MPa, and OEM-specific low-temperature drop tests using a 2.0 kg steel dart at -20°C. The rotomoulding cycle uses oven temperature 280–300°C, primary rotation 7–10 min⁻¹, secondary rotation 2–3 min⁻¹, and cook to internal air temperature 190–205°C; the critical processing boundary is demoulding temperature, kept below 55°C to prevent thread-insert distortion and flange warpage. Release agents are avoided on the thread inserts because residual silicon migration can reduce insert torque retention; the insert is preheated to 60–80°C before mould charging to promote resin encapsulation. End products include windshield washer reservoirs, hydraulic oil expansion tanks, and urea solution reservoirs with wall thickness from 3.5 mm to 7.0 mm.