判断标准是"与 PVC 相容性":相容性高、能进入分子链之间的叫内润滑(聚酯蜡、脂肪酸酯类),相容性低、迁移到熔体与金属界面的是外润滑(氧化聚乙烯蜡、聚乙烯蜡、石蜡)。硬质 PVC 通常内外并用。 The dividing line is compatibility with PVC: highly compatible grades that slip between chains act as internal lubricants (polyester wax, fatty acid esters); poorly compatible grades that migrate to the melt–metal interface act as external lubricants (oxidized PE wax, PE wax, paraffin). Rigid PVC normally needs both.
内润滑剂起什么作用? What does an internal lubricant do?
内润滑剂与 PVC 相容性好,插入分子链之间削弱链间作用力,降低熔体粘度、降低扭矩、促进塑化。聚酯蜡属于典型的极性内润滑剂,在保持制品透明性上有优势,适合高透明片材、透明膜。 Internal lubricants are highly compatible with PVC. They slip between chains, lower melt viscosity and torque and promote fusion. Polyester waxes are typical polar internal lubricants and are preferred where clarity matters, such as transparent film and sheet.
外润滑剂起什么作用? What does an external lubricant do?
外润滑剂与 PVC 相容性差,加工中迁移到熔体与螺杆、模口的界面,减少摩擦与粘附,延后塑化、防止析出。氧化聚乙烯蜡兼具极性与外润滑作用,是硬质 PVC 里最常用的品种之一。 External lubricants are poorly compatible. They migrate to the melt–metal interface, reduce friction and sticking, delay fusion and help prevent plate-out. Oxidized PE wax combines polarity with external lubrication and is one of the most used grades in rigid PVC.
内外润滑失衡会有什么表现? What happens when the balance is wrong?
内润滑过多会塑化过快、熔体强度下降、制品发脆;外润滑过多会塑化不良、制品表面出现析出物或"鲨鱼皮"、焊接强度下降。调整时按单一变量小步试,不要同时改多个品种。 Too much internal lubrication fuses too fast and lowers melt strength, giving brittle parts. Too much external lubrication delays fusion and causes plate-out, shark skin or weak weld lines. Change one variable at a time in small steps.
高填充配方该怎么配润滑体系? How should highly filled compounds be lubricated?
高碳酸钙填充配方对润滑剂的需求量更大,且要保证分散。极性结构、相容性好的聚酯蜡适合高碳酸钙填充体系,可同时改善流动性与制品表面光泽。具体用量以小试扭矩曲线为准。 Highly filled compounds need more lubricant and good dispersion. Polar polyester waxes with high compatibility suit high calcium carbonate loadings, improving flow and surface gloss. Set the dosage from a small-scale torque curve.
对比一览 Comparison
| 品种 Grade | 与 PVC 相容性 Compatibility with PVC | 作用定位 Role | 典型用途 Typical use |
|---|---|---|---|
| 聚酯蜡(ES 系列) Polyester wax (ES series) | 高 High | 内润滑,促进塑化、保透明 Internal: promotes fusion, keeps clarity | 透明片材、高填充管材、型材 Clear sheet, filled pipe, profiles |
| 氧化聚乙烯蜡(ST 系列) Oxidized PE wax (ST series) | 中 Medium | 内外兼顾,防析出 Internal + external, anti plate-out | 硬质管材、型材、注塑 Rigid pipe, profiles, injection |
| 聚乙烯蜡 / 费托蜡 PE wax / Fischer-Tropsch wax | 低 Low | 外润滑,延后塑化 External: delays fusion | 硬质挤出、电缆料 Rigid extrusion, cable compound |
| 微粉蜡 Micronized wax | — | 表面性能:耐磨、抗划伤 Surface: rub and scratch resistance | 涂料油墨、涂层 Coatings, inks |
常见问题 FAQ
内润滑和外润滑能只用一种吗? Can I use only one type?
取决于配方与设备。硬质 PVC 挤出通常内外并用才能兼顾塑化速度与脱模性;软制品与部分注塑配方可以偏内润滑为主。最好按扭矩曲线与制品外观确定。 It depends on the compound and the machine. Rigid PVC extrusion usually needs both to balance fusion speed and release; soft compounds and some injection grades can run mainly internal. Decide from the torque curve and the surface appearance.
润滑剂加多了会怎样? What if I overdose the lubricant?
最常见的是析出:制品表面起霜、印刷或粘接困难,模口积垢。发现析出应先把外润滑减量,再观察塑化时间是否回到正常区间。 The usual sign is plate-out: blooming on the surface, poor printing or bonding, and die build-up. Reduce the external lubricant first, then check that fusion time is back in the normal window.
聚酯蜡和单甘酯(GMS)能互相替代吗? Can polyester wax replace GMS?
部分可以。有专门按 GMS 替代定位的聚酯蜡型号,在保持内润滑的同时改善热稳定性与析出倾向。替代前应按同一配方做对照小试,比较扭矩、透明性与析出情况。 Partly. Some polyester wax grades are designed as GMS replacements, keeping internal lubrication while improving heat stability and reducing plate-out. Always compare torque, clarity and plate-out in a side-by-side trial.
透明度要求高时优先选哪种? Which grade for high clarity?
优先选相容性好、极性适中的聚酯蜡。相容性差的外润滑剂在高透明配方里容易雾度上升,用量要压到最低。 Choose a polyester wax with high compatibility and moderate polarity. Poorly compatible external lubricants raise haze in clear compounds and should be kept at the minimum dosage.
参考资料 References
本页内容用于选型参考,具体指标以该批次的 COA 与 TDS 为准。