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1、交交联电缆苑会林北京化工大学交联聚乙烯电缆的特点由于交联聚乙烯为体型大分子,故为不熔不溶物,耐热性明显提高。交联度低,软化点变化不大;交联度高,维卡耐热温度可提高3040;交联聚乙烯的长期使用温度为95100。交联聚乙烯电缆的特点交联聚乙烯结晶区减少,密度均匀,使其电绝缘性基本无变化,所以仍属好的绝缘材料,并且绝缘性在较高温度和苛刻的化学介质中仍能保持高值,常用于电缆护套层。由于分子链间架起化学链桥,物理力学性能提高,特别是硬度、刚度、耐磨性、耐蠕变性和耐尺寸稳定性;同时因为交联部分的分子链虽受限制,但还可在原位置附近作轻微振动以消耗冲击能,故冲击强度也提高。交联电缆的方法过氧化物交联硅烷交联
2、（一步法、两步法）电子辐照交联过氧化物交联工艺DCP 用量与凝胶含量的关系试验基本配方为:PE100份;抗氧剂10100.5份;DCP0.63.0份交联温度对凝胶含量的影响交联温度对凝胶含量的影响交联温度对凝胶含量的影响凝胶含量与材料力学性能的关系不同不同PEX 的电性能的电性能PEX-1为一般的过氧化物交联聚乙烯PEX-2为加炭黑后的过氧化物交联聚乙烯,炭黑本身有导电性,炭黑表面氧化程度高,其含氧基团起绝缘作用,增加炭黑会使体积电阻率下降。PEX-3为用作比较标准的意大利潘德那塑料公司生产的硅烷交联聚乙烯,比较表中数据可以看出,一般的过氧化物交联聚乙烯电性能较高。炭黑含量对凝胶含量的影响炭黑
3、含量对交联聚乙烯拉伸强度的影响炭黑含量对交联聚乙烯拉伸强度的影响ZnO 对交联聚乙烯凝胶含量的影响ZnO 用量对交联聚乙烯力学性能的影响抗氧剂对交联聚乙烯的影响抗氧剂用量对交联聚乙烯热性能的影响交联聚乙烯过氧化物交联电缆料XL 07407CopolymerWireandCableCompoundDensity1.40PETROTHENEXL07407isespeciallyformulatedforuseinflameretardantprimaryinsulationforlowvoltageautomotivewireandcable(SAEJ1128)applicationsandfor
4、ULapplicationsincluding125appliancewireandSIS.XL7407isanon-tarnishing,non-halogenated,flameretardant,chemicallycrosslinkablecompound.Non-discoloringantioxidantandspecialactiveperoxidehavebeenaddedtoensurethermalstabilityduringprocessingandoptimumcuringresults交联硫化通道Petrothene XL 07407过氧化物可交联无卤阻燃聚乙烯电缆
5、料加工应用试验。挤出试验设备挤出试验设备：单螺杆挤出机3025，片材模具280(mmmm)。温度设定：模具80100110120110挤出速度：1060转分冷却辊：三辊压光机，压片厚度1.5mm。后交联甘油浴温度：204交联时间：5，10，20秒推荐加工和应用条件推荐加工和应用条件PetrotheneXL07407CopolymerWireandCableCompound为过氧化物可交联无卤阻燃聚乙烯电缆料，可适用于电线护套和电线电缆穿线管，应用于公共场所建筑物、电梯间、民用住宅、车船的电线护套和电线电缆穿线管。本产品的特点：使用温度可耐120阻燃燃烧时无有毒气体放出燃烧时无烟或烟密度很低加工
6、推荐加工温度在107113，常规挤出机，螺杆长径比2025，压缩比2:1或3:1，口模要短，口径直径与产品直径放大比可达20%，挤出加工后进入高温盐浴或硫化通道204210进行后固化,停留时间1520秒。交联后的产品可用于125的场合。过滤网最大40目。使用前不需预干燥。电子束辐射加工电子加速器生产辐照交联电线电缆目前，全世界用于工业的电子加速器有700800台，总功率超过20000kW，其中200多台应用于电线电缆的辐照交联，主要集中在北美、欧洲、日本、俄罗斯、中国及韩国等国家。美国、日本等国几乎所有生产电线的大厂都利用电子加速器生产辐照交联特种电线电缆。我国现有电子加速器近60台，用于电线
7、电缆辐照交联的近50台。目前我国电线电缆辐射加工已成为辐射加工行业这个高技术产业的基础。但我国辐照交联电线电缆产品无论在规格、品种和技术等各方面与先进工业国家仍有相当大的差距。辐照设备10KV交联电缆料LDPE100敏化助交联剂1.5抗氧剂10100.30.6硬脂酸钙0.5氧化锌1.5碳酸钙1-4炭黑母粒（含量45%）26交联度80%辐照量20Mrad硅烷交联电缆料一步法两部分共聚合硅烷交联机理硅烷交联电缆料诺基亚一步法电缆生产线SILANE CROSSLINKED PE PEX OR XLPE电缆料料苑会林Silane Crosslinked PE is called PEX or XLPE
8、 无卤阻燃塑料一个新的发展是在无卤阻燃聚烯烃电缆料中采用纳米层状硅酸盐，以改善材料的阻燃性和降低无机阻燃剂的用量。如在以氢氧化铝阻燃的乙烯-乙酸乙烯酯电缆料中加入5%以下的纳米层状硅酸盐，电缆料中氢氧化铝的含量(质量分数)可由原来的65%降至45%，而材料释热速率峰值仍保持不变，且加工性、成炭性、耐光性和生烟性均有改善。 XPEPEX Pipes Heat Shrinkable tubes Wire and Cable main processes Aone step process,calledMonosilAtwo step processcalledSioplasMonosil proc
9、ess (One step process) Sioplas process (Two steps process) Effect of silane structure VTMOS (Vinyl trimethoxysilane) reacts much faster than VTEOS (Vinyltriethoxysilanes). Effect of silane concentration The maximum concentration of VTMOS recommended is 2wt% concentrations can be used but these can r
10、esult in lower gel contents which might very well prove to be suitable for some applications. Concentrations higher than 2wt% do not lead to significant higher gel contents. Effect of silane concentrationInfluence of the Organic Peroxide on PE Crosslinking The peroxide to be used needs to have decom
11、position kinetics which are suitable for the temperatures and residence times involved in the procesing of polyethylene. Generally DCP, Dicumyl peroxide or BPDIB; t-Butyl di-iso propyl benzene are recommended. The peroxide level required will vary with individual characterics such as :Melt flow inde
12、x the initial polyethylene, density, polymerization process.) Desired melt flow index of the grafted PEProcessing temperature during graftingPresence of some additives or fillers Influence of the Catalyst on PE CrosslinkingDBTDL,dibutyltindilaurateisthepreferredcatalystforcrosslinking.Sincetheconcen
13、trationofDBTDLaffectssignificantlyprocessabilityofthemixtureofgraftcopolymers,itissometimerecommendedtouseitaslowas0.25wt%This reduction in concentration reduces the rate of crosslinking but does not affect the gel content of fully crosslinked graft copolymerInfluence of the Process Conditions on PE
14、 Crosslinking Process conditions also have a strong impact on moisture crosslinking and final performance. Two key parameters are water temperature and wall thickness of the extruded profile. Water temperature Wall Thickness Wall Thickness壁厚 The Crosslinking reaction is fast but diffusion of moistur
15、e into the material is a limiting factor. For this reason, the wall thickness of the extruder parts have a strong influence on the time needed to crosslink it. High Speed LineNo Special Equipment RequiredBy adopting a SIOPLAS process, converters have the ability to use commercially available pre-gra
16、fted polyethylene (Silanized PE) that can be premixed with a catalyst masterbatch and colormasterbatch. Increased Maximum Operating Tempeatures PEX continuous service temperature is around 100-120C. gel influences thermo-mechanical performances of PEX. Increased Chemical and Environmental Crack ResistanceBetter Tensile and Impact Performance
