Frequently Asked Questions (FAQ) About Flame Retardancy in Corrugated Tubing

Dealing with blooming, sticky surfaces, or white mold deposits on your flame-retardant corrugated pipes? It's not just an appearance issue—it means your active flame retardants are migrating out. Discover the root causes of FR blooming and how YINSU's high-compatibility masterbatches (like FRP-950X) lock in performance from the source.

Q1: Why does the surface of a corrugated tube treated with a flame retardant turn white and develop a frosty appearance after being stored for a period of time?

This is a precipitation issue caused by poor compatibility between the flame retardant and the PE substrate. The small molecules in traditional flame retardants are in a “supersaturated” state within the PE. Over time, and as environmental temperature and humidity fluctuate, they gradually migrate to the surface of the product, forming a white powder or frost-like substance. The higher the temperature and the greater the humidity, the faster the precipitation occurs. PE-XT-141 forms a uniform and stable dispersion system through melt blending, preventing precipitation or frosting even after long-term storage.

Q2: Why do flame-retardant corrugated tubes feel slightly sticky to the touch after being stored in a warehouse for a while?

The sticky surface is also caused by the migration of small-molecule flame retardants or additives to the surface. Some low-molecular-weight additives can seep out from the interior in high-temperature, high-humidity environments, forming oily or sticky substances. PE-XT-141 employs a reactive-additive hybrid technology approach, in which the flame retardant forms a stable dispersion with the PE matrix, preventing migration or precipitation and ensuring the surface remains dry at all times.

Q3: If a flame-retardant corrugated tube experiences precipitation issues, will this affect its flame-retardant performance?

Yes, it does. The exudation of flame retardants means that effective flame-retardant components are leaching out from the interior of the product, leading to a localized decrease in flame-retardant concentration and unstable flame-retardant performance. The white powder exuding onto the surface also affects the product’s appearance and subsequent processing (such as inkjet coding and printing). Yinsu's PE-XT-141 and FRP-950X systems both ensure that flame retardants remain stably retained within the base material over the long term, with no degradation in flame-retardant performance.

Q4: Why does a layer of white powder form on the mold during extrusion even after adding flame-retardant masterbatch?

The white powder on the mold is “mold residue” formed by the migration of flame retardants during high-temperature processing. The higher the processing temperature, the more severe the migration. PE-XT-141 uses a highly compatible formulation system that prevents sticking to the mold and screen clogging during processing, significantly reducing the frequency of mold cleaning.

Q5: When making flame-retardant corrugated tubing, how can I determine if a flame-retardant masterbatch will precipitate?

Three quick methods: First, assess the compatibility between the masterbatch and the base material—poor compatibility indicates a high risk of precipitation. Second, conduct an accelerated aging test—place the finished product in an oven at 70°C for 72 hours and observe whether any precipitates appear on the surface. Third, check for carbon buildup or white powder accumulation on the die head during production. Yinsu’s PE-XT-141 and FRP-950X have both passed long-term storage and high-temperature, high-humidity environment tests, showing no frosting or exudation.

Q6: Can corrugated pipes that have already exhibited exudation be salvaged?

Minor surface exudation can be removed by wiping the white frost off with alcohol or a specialized cleaner; however, this is only a temporary fix and does not resolve the issue of ongoing internal migration. The fundamental solution is to switch to anti-precipitation flame-retardant masterbatches—PE-XT-141 (white system) or FRP-950X + aluminum hydroxide (halogen-free system)—to eliminate precipitation at its source.

Which one you choose depends on your product color, environmental requirements, and cost objectives.