PES材料加工成型:PES可按一般热塑性塑料的方法进行成型加工，无需特殊设备，可采用的方法有：注射、挤出、模压、流涎、塑、真空成型、发泡成型和涂覆成型，但以注射和挤出为主。注射成型用于加工工程零部件，应选用螺杆式注射机，以等矩渐变螺杆为主，均化段螺槽应比一般螺杆深，以避免熔体受到过高的剪切摩擦热。喷嘴宜用直通式，模具设计时应避免出现熔接痕。PES熔体为塑性体，即熔体表观粘度随剪切速率的增加呈下降趋势，但下降幅度并不大。但是当PES在正常加工温度范围内(310-335℃)长时间或多次加工时，会出现熔体增稠现象，可能是剪应力导致分子链断裂形成了自由基，自由基使分子链产生支化或轻度交联所致。因此加工PES时应控制熔体在设备中不要停留过长时间，一般不应超过40min。PES在加工前也应干燥，使含水量降至0.12%以下，干燥条件为120～140℃时l0h或160℃时3h以上。(3)PES的熔融温度范围较窄，大约为315-335C，熔体冷却速率较快，因此应采用较高的注射速率将熔体送人模具，以避免熔料充模流动性变差而使制品欠料。PES在成型时一般均形成无定形结构，因此挤出时的出模膨胀率较小，注射时的收缩率也较小，但当加入少量的成核剂时也会形成晶体结构。
Processing and molding of PES materials: PES can be molded andprocessed according to the methods of general thermoplasticswithout special e The methods available include:injection, extrusion, molding, salivation, plastic, vacuum molding,foam molding and coating molding, but mainly injection andextrusion. Injection molding is used to process engineering partsand components. Screw injection machine shall be selected, mainlywith equal moment gradual change screw. The screw groove ofhomogenization section shall be deeper than that of ordinary screwto avoid the melt being subjected to excessive shear friction heat.The nozzle should be straight-through type, and the weld markshould be avoided during the mold design. The PES melt is plastic,that is, the apparent viscosity of the melt decreases with theincrease of shear rate, but the decrease is not significant.However, when PES is processed for a long time or several timeswithin the normal processing temperature range (310-335 ℃), themelt thickening phenomenon will occur, which may be caused by themolecular chain fracture caused by shear stress and the formationof free radicals, which make the molecular chain branched orslightly cross-linked. Therefore, when processing PES, the meltshould not stay in the e for a long time, which should notexceed 40min generally. The PES should also be dried beforeprocessing to reduce the water content to below 0.12%, and thedrying conditions are 120~140 ℃ for 10h or 160 ℃ for more than 3h.(3) The melting temperature range of PES is relatively narrow,about 315-335C, and the melt cooling rate is relatively fast.Therefore, a higher injection rate should be used to send the meltinto the mold to avoid the shortage of products due to the poormelt filling fluidity. PES generally forms amorphous structureduring molding, so the extrusion expansion rate is small and theshrinkage rate during injection is also small, but crystalstructure will also be formed when a small amount of nucleatingagent is added.
