Pvc waterproof membrane (calendered laminating process) outdoor weather-resistant feasibility plan

Recipe Core Logic

1. Weathering Enhancement:"UV absorbers + antioxidants + light-blocking pigments" form a closed-loop protection to address degradation issues caused by outdoor ultraviolet rays, high temperatures, and high humidity.

2. Performance balanceThe total number of plasticizers remains unchanged, utilizing a combination of DOTP as the main component and ESO+DOS as supplements, which ensures flexibility and prevents migration; the addition of processing aids and lubricants ensures stability during the calendering process.

3. Cost controllable:The total addition of weather-resistant additives is about 3.1 parts, increasing the cost by 800-1000 yuan per ton. Compared to traditional formulations, it offers a higher cost-performance ratio and can meet long-term weather resistance needs.

Focus on controlling the mixing, calendering, laminating, and post-treatment processes to reduce defects such as bubbles, crystal points, and delamination, as these defects can accelerate outdoor aging and shorten the lifespan.

1. Pre-mixing process (ensure uniform dispersion)

- EquipmentHigh-speed mixer + cooling mixer

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1. Low-speed stage (500r/min): Add PVC resin powder, calcium-zinc stabilizer, UV-531, and antioxidant 1010, and mix for 3 minutes to ensure the stabilizer and weather-resistant additives evenly coat the resin.

2. High-speed phase (1200r/min): Add plasticizers (DOTP→ESO→DOS in sequence), heat to 85-90℃, and maintain the temperature for 5 minutes to ensure that the plasticizers are fully absorbed by the resin without any free residue.

3. Supplementary Addition Stage: Add calcium powder, titanium dioxide, ACR-401, and lubricant, and mix at high speed until the temperature reaches 110-115°C (the material appears as loose granules). Immediately discharge into a cooling mixer and cool to below 40°C before discharging.

Core RequirementsThe mixed material has no clumps or white lumps, with a dispersion uniformity of ≥95%, preventing local insufficiency of additives that could lead to processing degradation.

2. Rolling Forming Process (Control of Thickness and Surface Quality)

- EquipmentFour-roller calender (roller diameter Φ600-800mm)

- Key Parameters：

Other parameters:

- Rolling speed: 8-12m/min (excessive speed may lead to uneven thickness, deviation must be ≤±5%);

- Roll gap adjustment: According to the target thickness (2.0-3.0mm, no less than 2.0mm for outdoor use), decrease sequentially as "first roll > second roll > third roll > fourth roll" for gradual compaction.

3. Bonding Process (if composite polyester substrate)

- Fetal base preprocessingPolyester tire is dried by hot air (80-90℃, for 3-5 seconds) to remove surface moisture, preventing bubbles after bonding.

- Fit parametersThe temperature of the laminating roller is 160-165℃, with a pressure of 0.8-1.0MPa. After laminating, it immediately enters the cooling roller (25-30℃) for setting, with a cooling time of ≥5 seconds to ensure a firm bond between the carcass and the PVC layer without delamination (delamination can lead to moisture infiltration, accelerating internal aging).

4. Post-processing Techniques

- Trimming and ReelingTrim width is controlled within ±5mm, rewinding speed is synchronized with calendering speed (8-12m/min), and rewinding tension is 50-80N (excessive tension can easily cause stretching and deformation, while insufficient tension can lead to looseness).

Aging treatmentAfter rolling, place it in a curing chamber (40-50°C, humidity ≤60%) for 24 hours to allow the plasticizer to further diffuse evenly, reducing the shrinkage rate in the later stage (shrinkage rate after curing ≤1.5%).

WeatherabilityAccording to GB/T 18244-2000, conduct a xenon lamp accelerated aging test (irradiance 0.71W/(m²·nm), 65℃, 50% humidity). After 1000 hours, the tensile strength retention rate should be ≥80%, and the elongation at break retention rate should be ≥70%, corresponding to an outdoor lifespan of 8-10 years.

2. Processing FeasibilityThe formulation exhibits good material flow at a calendering temperature of 150-170°C, without sticking to the roller or forming crystalline points. After lamination, the surface of the rolled material is smooth, with a thickness deviation of ≤±3%.

3. Environmental Compliance:All materials comply with RoHS standards, the plasticizers are free of phthalates, and the calcium-zinc stabilizers contain no heavy metals, meeting the requirements for outdoor environmental use.