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This paper focuses on the common appearance defects of dull and foggy surfaces in PVC pipe fitting production, breaks the misunderstanding of attributing problems to a single fault point, and systematically sorts out more than ten core inducing factors from the whole process dimensions of raw material formula, processing technology, environment and mold, including additive precipitation, excessive moisture in raw materials, temperature control deviation, excessive workshop humidity and poor mold condition. It covers various influencing factors from basic material properties to production operation details, helping production practitioners quickly locate the root cause of problems, clarify the underlying logic that causes appearance fogging and luster dullness in the whole process of PVC pipe fittings from raw materials to molding, and provide a complete troubleshooting reference for targeted solving such appearance defects in mass production.

The core objective of wax selection is to simultaneously meet four requirements: lubrication balance, foaming stability, surface gloss, and non-blooming. In terms of viscosity selection, high-viscosity polyethylene wax offers superior gloss and higher molecular weight with low bloom tendency despite slightly poorer dispersion, making it suitable for products with hazy surfaces that require brightness enhancement. Low-viscosity wax provides good dispersion but is prone to migration and blooming, making it only suitable for formulations with high dispersion requirements. The recommended wax types in order of preference are: high-density polyethylene wax for high-temperature processing, oxidized polyethylene wax for balanced internal and external lubrication with low bloom tendency, Fischer-Tropsch wax for its narrow molecular weight distribution and excellent foaming stability, while cracked wax is not recommended for high-gloss products due to significant quality fluctuations. Key selection pitfalls to avoid include choosing a melting point of 100–140°C, particle size of 5–20μm, and controlling the addition amount at 0.1–0.4 phr. Pure polyethylene wax must be used, avoiding recycled wax or inferior cracked wax that can cause surface stains and dullness.

Cause: Summer heat broadens molecular weight distribution (more low-MW fractions) and softens wax during production/storage. Humidity adds to stickiness. Not caused by: Melt viscosity or normal oil content. Negative effects: Disrupts plasticization, sticks to equipment, poor dispersion; causes blooming, lower thermal stability, printability issues. Solution: Adjust process, ensure cooling, store at low temperature.

A technical analysis of oxidized polyethylene wax selection criteria for polyolefin garment fiber masterbatch systems. The article focuses on the precise adaptability of SCG ox102P across critical indicators—low viscosity (≈200 cPs), high thermal decomposition temperature (>250°C), and moderate acid value (≈16 mg KOH/g)—and presents a side-by-side comparison with two typical general-purpose oxidized wax products on the market. It reveals the fundamental reason why products within the same oxidized wax category are not interchangeable: the magnitude of difference in viscosity and thermal stability constitutes an insurmountable process barrier. This analysis serves as a technical reference for raw material selection in fiber masterbatch enterprises.

Monoglyceride‌ is a natural emulsifier that leverages its "lipophilic-hydrophilic" dual nature to bind water and oil. Produced via ‌conventional synthesis‌ and ‌molecular distillation purification‌, the ‌high-purity form‌ (over 90%) delivers superior performance in food, cosmetics, and pharmaceuticals compared to the ordinary grade (40%), making it an "invisible helper" in enhancing product texture and stability.

‌Acid value is the core indicator determining the performance of plastic additives‌, as its level directly affects the additive's polarity, lubrication type, compatibility, and thermal stability. ‌High acid value (16–30 mgKOH/g) in high-density oxidized polyethylene wax‌ enhances internal lubrication, significantly accelerating PVC plastification, making it suitable for highly filled rigid products such as SPC flooring and pipes. ‌Low acid value (10–15 mgKOH/g) in low-density oxidized wax‌ emphasizes external lubrication, improving demolding and surface gloss, ideal for film applications. ‌EBS, oleamide, and erucamide‌ require strict control of acid value ‌≤7.0 mgKOH/g‌ to ensure minimal blooming, high thermal stability, and reliable performance—functioning respectively as lubricant-dispersants in PVC processing, fast-acting slip agents in general PE films, and long-lasting anti-blocking agents in high-speed packaging films. The acid value is deeply tied to the molecular structure and application environment of the additive. ‌Precise matching of acid value enables optimal balance between processing efficiency and product quality‌.