Rotomolding Water Tanks & Storage Containers — Food-Contact, Anti-Extraction

Rotomolding Water Tanks & Storage Containers — Food-Contact, Anti-Extraction

💧 Rotomolding Water Tanks & Storage Containers

Drinking water, household water storage, RV water tanks, chemical liquids, pesticides and fertiliser tanks — Tiangang additives provide a complete package of food-grade compliance, extraction resistance and long-term weathering for "water-holding / liquid-holding" applications.

1. Demanding Operating Conditions of Water Tanks and Storage Containers

Water tanks and storage containers are one of the largest rotomolding applications, but also one of the most complex scenarios for additive formulation — they must simultaneously meet the triple challenge of "food-grade compliance + long-term weathering + resistance to extraction by the medium".

  • Food / drinking water contact: must comply with FDA 21 CFR, EU 10/2011, Chinese national standard GB 4806.7 and other regulations
  • Migration resistance: the light stabilizer must not migrate into the water (SML limit)
  • Extraction resistance: must not be extracted during long-term contact with water, acid/alkali cleaning agents and disinfectants
  • Long-term outdoor service: 10+ year warranty requires a QUV 16k+ grade
  • Anti-microbial: long-term water storage easily breeds algae and bacteria, so the formulation must consider anti-fungal protection
  • Structural stress: large storage tanks have walls 8–15 mm thick, and the light stabilizer must be well dispersed into the core layer

2. Tiangang Recommended Solutions

Solution A: Household / RV drinking water tanks (food grade, high weathering) — Tiangang Top Pick

ComponentModelRecommended DosageFunction
Compounded light stabilizer packageHS-3620.35%Light stabilization + antioxidation + processing stability, three tasks in one package; molecular weight > 2000, 10% weight loss > 350℃, withstands long dwell at 250℃ in rotomolding
Supplementary UV-A (optional)UV-3600.10%High-temperature UV absorber that suppresses initial color change; melting point 195℃, flash point > 200℃
Upgrade: acid/alkali immersion resistanceXT-80.25%The N-OR structure does not react with acidic substances; sulfur resistance 3000~7000 ppm, chlorine resistance ≤ 850 ppm
Why recommend HS-362 instead of blending four single components yourself: water tank manufacturers usually do not have the development capability to balance additive synergies. Inside HS-362 the synergy between light stabilizer and antioxidant, the staged interception sequence, and the dual-stage protection for the processing stage and the service stage have already been designed — feeding is done in a single step, with no trial blending and no multi-component weighing.

Solution B: Chemical liquid storage tanks (acid / alkali / salt environments) — Tiangang Top Pick

ComponentModelRecommended DosageFunction
Acid-resistant dedicated one-packT-680.40%Compounded light stabilizer dedicated to acid and other harsh environments, melting point 80~100℃, weight loss > 300℃; ready to use straight from the bag, zero trial-blending cost
Upgrade: export compliance / strongly corrosive mediaXT-8 + HS-6250.25% + 0.20%N-OR high molecular weight + polymeric HALS two-tier protection, extraction resistant, already registered under EU REACH / US TSCA
The value of T-68: acid and alkali media neutralize the basic nitrogen of classical HALS, so the light stabilization function decays quarter by quarter — this is the most common failure cause of chemical tanks. T-68 is a one-pack developed by Tiangang specifically for acid and other harsh environments, so customers do not have to redo formulation validation themselves.

Solution C: Pesticide / fertiliser / agricultural irrigation containers (sulfur and chlorine containing) — Tiangang Top Pick

ComponentModelRecommended DosageFunction
Pesticide-resistant dedicated one-packT-66 / T-690.40%Light stabilizer package dedicated to agricultural film with pesticide resistance, melting point 90~130℃; optimised for sulfur-containing pesticide media
Upgrade: high sulfur concentration (3000 ppm+)XT-8 + HS-6250.25% + 0.15%XT-8 measured sulfur resistance 3000~7000 ppm, chlorine resistance ≤ 850 ppm; verified in a 38-month field greenhouse trial with mechanical property retention of 50%+

Solution D: Functional masterbatch solution (first choice for small and medium water tank plants) — Tiangang Top Pick

ModelActive IngredientRecommended DosageApplication
TGUVFQ2001PEHALS compounded UV-resistant system3~5%Dedicated to thick-wall articles — water tank walls are far thicker than film and need a higher active load and a slower release curve
MB0607-1Active HALS 15% + active antioxidant 5%2~4%General-purpose for PE; the weathering formulation is completed in one step, with dust-free feeding and better dispersion than direct powder feeding
MB0607-2High-molecular-weight HALS compound2~4%PE-based articles with high weathering requirements
Masterbatch conversion: target addition level ÷ active ingredient concentration of the masterbatch = masterbatch dosage. Example: target HALS active content 0.3%, using MB0607-1 (15%) gives masterbatch dosage = 0.3% ÷ 15% = 2.0%. Tiangang can convert the feeding amount directly from the customer's formulation.

Solution E: Recycled-material water tanks (degraded material + improved dispersion)

ComponentModelRecommended DosageFunction
Compounded light stabilizer package (increased)HS-3620.50%Recycled material is degraded to varying degrees, so the dosage must be raised to compensate for the insufficient active component
Multifunctional processing aidAO-4270.20%CAS 42774-15-2, melting point 268~275℃; thermal stability + processing stability + improved tinting performance, suppressing the rise in acid value

3. Food-Contact Compliance and Certification

Tiangang's compliance support for food-contact applications:

  • FDA 21 CFR: HS-944, HS-770, HS-962, AO-1076 and AO-168 are all on the indirect food-contact permitted list (SML/QM calculations required)
  • EU 10/2011 (PIM): HS-944, HS-950, UV-360 and XT-8 have passed the EU compliance review for plastics in food-contact materials
  • GB 4806.7: the Chinese national standard for domestic food-contact plastic additives; Tiangang additives meet the limit requirements
  • NSF / WQA: third-party certification support can be provided (please enquire for specific models)
Recommendation: before formal mass production, request the "Food-Contact Compliance Statement" (FDA / EU / GB) for the relevant model from Tiangang, and carry out migration testing (SML/OML/QM) according to the final article specification.

📂 Other rotomolding scenarios

← Back to the rotomolding application overview 🎠 Rotomolding playground and public infrastructure ⛽ Rotomolding fuel tanks and industrial components

Need a specific formulation for drinking water tanks or chemical tanks?

Describe your substrate, wall thickness, target service life and compliance requirements (FDA/EU/GB), and the technical center will respond with a solution within 48 hours.

Contact the technical team →
Technical reviewTiangang Technical CenterVersion2026-11-07
Specifications and application notes on this page are compiled from Tiangang's published technical data. Actual values are governed by the COA shipped with each lot and the technical agreement confirmed by both parties.

Certifications

  • National High-Tech Enterprise
  • Vice Chairman Unit, China Plastics Processing Industry Association (CPPIA)
  • Vice Chairman Unit, Agricultural Plastics Branch, China Agricultural Plastics Application Technology Society
  • Member, Ageing Methods Subcommittee, National Technical Committee on Plastics (SAC/TC15/CS5)
  • Member, Society of the Plastics Industry (SPI), USA

Recommended Products

Products

UV Absorbers

400-094-4362