课程设计-塑料方凳注射成型设计.doc_第1页
课程设计-塑料方凳注射成型设计.doc_第2页
课程设计-塑料方凳注射成型设计.doc_第3页
课程设计-塑料方凳注射成型设计.doc_第4页
课程设计-塑料方凳注射成型设计.doc_第5页
已阅读5页,还剩20页未读 继续免费阅读

下载本文档

版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领

文档简介

高分子材料成型加工设计说明书塑料方凳注射成型设计起止日期: 2010年 6月 28日 至 2010年 7月4日学生姓名222班级高分子材料与工程071班学号07404300110成绩指导教师(签字)包装与材料工程学院2010年 7 月 4 日目 录第一章 制品基本条件的确定21.1制品基本参数的确定21.2制品的成本估计2第二章 方凳结构设计2第三章 选材及配方设计43.1基材和性能分析43.2 配方设计4第四章 注射量计算及注射机的初步确定54.1 注射量的计算54.2 注射机的初步确定6第五章 浇注系统设计计算7第六章 成型零件工作尺寸及模具设计86.1型芯的设计86.2型腔的设计9第七章 模具加热与冷却系统设计与校核137.1加热系统设计与校核137.2冷却系统设计与校核13第八章 注射压力、锁模力和安装尺寸校核及注射机的选定168.1注射压力的校核168.2锁模力的校核168.3 安装尺寸与工艺的设计与校核178.4 注射机的确定18第九章 成型工艺条件18第十章成本及利润核算1910.1 方凳的成本1910.2每天的利润19第十一章 课程设计总结20第一章 制品基本条件的确定1.1制品基本参数的确定该制品为塑料方凳,作为可以承受成人体重的凳子,现在人一般在80Kg以下,则需要方凳能承受的载荷条件要达到784N; 塑料方凳的主要用于湖南等南方城市一带,要能承受40的高温和10的低温;塑料凳子要能耐磨,硬度也要高,设计洛氏硬度70;弯曲强度45MPa;凳子成型收缩率要低,这样才不至于变形,收缩率55 J.m-2;同时,凳子的韧性必须好,这样才能不至于太脆而易损坏,则需断裂伸长率100-200%。1.2制品的成本估计为了获得更大的利润,必须控制单张凳子的成本在7元左右。第二章 方凳结构设计根据现在人得平均身高和体型特征,可设计方凳的高度为500mm,上表面宽度为300mm,腿的侧边和上边缘分别为70mm,中部加强横档为50mm。设计的方凳示意图和效果图如图1(a)所示;图1中的(b)图为凳子底部加强筋的示意图,有了这些加强筋,力学性能就更好,则能承受784N的力。(a)(b)图1第三章 选材及配方设计3.1基材和性能分析根据以上制品的用途及所需达到的性能,决定选用聚丙烯作为基体树脂来做这个塑料方凳。聚丙烯是一种高结晶度的聚合物,由于C-O键的键长比C-键短,因而聚丙烯轴方向的填充密度大,由于侧甲基的位阻效应,成螺旋结构。聚丙烯韧性好,耐热性好,可在100以上温度上工作,但低温下耐冲击强度不高。下表为基体树脂聚丙烯的主要性能指标。表1 聚丙烯的主要性能指标密度()0.90弯曲强度/MPa50结晶率/(%)0.94-0.96热变形温度(1.82MPa/112.5-126.6吸水率24h长时期(%)0.01-0.03剪切强度/MPa54-67洛氏硬度/MPaR80R110拉伸强度/MPa29拉伸强度/MPa60-70压缩强度(屈服)/MPa112.5-126.6断裂伸长率(%)200缺口冲击强度/()0.53.2 配方设计由于聚丙烯价格很高,达到6875元一顿,为了降低成本,需加入一些其他的助剂来满足要求,但加入助剂就会降低聚丙烯的力学强度。GF和LCP的配合使用时得其增强效果更好,它们的作用是改善制品的力学性能,使制品强度达到预期的效果;PP的成型收缩率很大,为了达到要求的0.7%,也为了降低成本,需加入碳酸钙,但会使PP的韧性下降;POE由于加入了填料及增强材料,需加入增韧剂来改善PP的韧性;PP的在10时耐冲击强度低,而且各项性能指标均不好,则需加入耐寒剂EPDM;由于凳子会经常用来做,则需很好的耐磨性,而PP本身是质地比较软的树脂,则需加入耐磨剂来改善性能,石墨和配合使用是很好的耐磨增强剂;PPgMAH是相容剂,因为PP和POE以及EPDM同时使用时相容性达不到,而PPgMAH做相容剂时能使得这三者达到很好的相容性;KH-550是作为的偶联剂,因为是无机物,而树脂等式有机物,加入偶联剂能增进无机物和有机物之间的粘合性能;由于PP的结晶度很高,熔融流动性不强,需加入润滑剂来改善它的流动性,HSt润滑剂兼有内,外润滑的作用,除了改善流动性,能增加塑料表面的润滑性;PP的抗紫外光老化性能较差,而塑料方凳很多时候会用在一些餐馆摆出的户外摊位上,所以必须加入紫外光吸收剂来增强制品的抗紫外光老化性能;钛白粉,群青,酞菁蓝组合的使用是使得制品的颜色是深蓝色,这是种接近自然的颜色,用的很广。由上述这些分析可将方凳的配方设计如下:表2 方凳的配方组分名称分数树脂PP100增强材料及耐热剂GFLCP3010填料50增韧剂POE15耐寒剂EPDM15耐磨增强剂石墨105相容剂PPgMAH5偶联剂KH-5501润滑剂HSt1紫外线吸收剂UV-327三嗪-50.50.5抗氧剂1010DLTP0.10.2颜料钛白粉群青0.120.03基色酞菁蓝0.01第四章 注射量计算及注射机的初步确定4.1 注射量的计算方凳体积的计算: (1)式中 =3003002.5=225000=225 =300702.54=210000=210 =43070242.5=602000=602 =238.4502.54=119200=119.2所以有 V=225+210+602+119.2=1156.2V-方凳总体积;V1-上表面体积;V2-上部边缘体积;V3-凳子腿体积;V4-凳子横梁体积。所以根据产品形状结构方凳体积为V=1156.2方凳质量为M=VD1=1156.20.95=1098.39g=1.10Kg (2)M-方凳质量;D1-方凳用料固体密度。M=1.10Kg符合1Kg左右。注射量的计算:D-方凳用料熔体密度。4.2 注射机的初步确定根据以上条件可选取得注射机型号可以有:SZ2500/500,SZ4000/800这两台注射机均为浙江塑料机械厂生产,其主要工艺参数如下表:表3 SZ2500/500型注塑机工艺参数型号单位数值理论注射容积2500注射速率570注射压力150螺杆转速0120锁模力5000移模行程850喷球口半径SR35喷球口孔径SZ4000/800型注塑机工艺参数型号单位数值理论注射容积4000注射速率770注射压力150螺杆转速080锁模力8000移模行程1200喷球口半径SR35喷球口孔径第五章 浇注系统设计计算浇注系统由主流道,冷料穴,浇口组成,无分流道。下图为主流道结构简图。图2 主流道的结构主流道截面尺寸:a: 主流道半锥角,取=,内壁表面粗糙度一般为um以下。b:R1为喷嘴球径;主流道对接处的半圆形凹坑半径R2:=39.4+1=40.4mm。凹坑深。c:主流道长度,大端直径为,小端直径比喷嘴直径大。冷料穴的设计:冷料穴一般位于主流道末端分型面的动模一侧。其作用是捕集熔体流动的前锋冷料,避免冷料进入模腔,对塑件造成不利影响。开模时又将冷料拉出,因而冷料穴直径稍大于主流道大端直径,该模具采用带球行头拉料杆的形冷料穴。其中主流道大端直径为,该设计中冷料穴深度为:第六章 成型零件工作尺寸及模具设计型芯、型腔基本尺寸校核:6.1型芯的设计6.1.1 凸模:(1)型芯径向尺寸:设塑件内型尺寸为,塑料平均收缩率为,其公差为,则其平均尺寸为;型芯基本尺寸为,制造公差为,其平均尺寸为。则,得: (3)式中 即 式中 =0.10. =0.033.平均收缩率: =0.65%所以 型芯大端径向尺寸计算如下:=341mm =341+3410.0065+0.750.10=343.3mm型芯小端径向尺寸计算如下:;=297.5+297.50.0065+0.750.10=299.5mm(2)型芯高度尺寸.:按公差带标注原则,塑件高度尺寸为,型芯高度尺寸为,因磨损小,计算时磨损量可不予考虑则 (4) = 即 式中 ;查表得 ;所以 =497.5+497.50.0065+0.670.10=500.8mm 6.2型腔的设计6.2.1 凹模:(1)凹模径向尺寸:设塑件平均收缩率为;塑件外型基本尺寸为,其公差为,则塑件平均尺寸为;凹模基本尺寸为,其制造公差为,则凹模基本尺寸为。 (5)式中 Ls=343.6 mm ;查表得;所以: =343.6+343.60.0065-0.750.10=345.8(2)凹模深度尺寸:按公差带标注原则,塑件凳子腿高度尺寸为,凹模深度尺寸为,凹模底面和型芯端面均与塑件脱模方向垂直,因磨损小,计算时磨损量可不予考虑。则 (6) =即 成型整个方凳的凹模深度:=500mm ;查表得;所以 =500+5000.065-0.670.10=532.43方凳成型时型腔设于凸模上,由于凳子中段加强档的原因导致凸模上有凸起部分而不易脱模,则脱模采用瓣合模,及凸模由四瓣组成,中间有根圆杆,在注射成型过程中,除最后脱模过程,圆杆一直与凸模的前端平行,当凹模离开后,圆杆后移使得凸模四瓣向中间移动,同时四个凳脚上的推杆向前推动塑料方凳,从而顺利脱模。模具的结构简图如下图所示:(a)模具配合剖面图(b)凸模主视图(c)凸模顶部俯视图图3第七章 模具加热与冷却系统设计与校核7.1加热系统设计与校核:PP结晶度高,熔体凝固速率很快,会造成充模困难、制品表面出现皱折等缺陷,因此宜将模温控制在70;所以仅靠注入高温塑料来加热模具是不够的,还需设置加热装置。此处用电热棒加热。相关计算:(1),电加热模具所需总功率:按经验公式有 (7)式中G-模具质量,Kg;q-加热单位质量的模具到规定温度时所需要的电功率,其大小由查表得设计模具质量为50Kg。所以(2),所需电热棒的根数的计算 (8)式中 n-电热棒的根数; Pe-电热棒的额定功率,W。选取Pe=30W,所以故所需电热棒根数为50根。7.2冷却系统设计与校核:(1)单位时间(每分钟)内注入模具中塑料的质量(M0),Kg/min; M0 (9)式中:-单位重量的塑件在凝固时所放的热量,; -冷却水的体积流量,; -冷却水的密度,; -冷却水的比热容,; -冷却水的出口温度,; -冷却水的入口温度,。查表可知:=590;=0.0092;=1000; =4.2; 设计中设定=45,=25。则M0 Kg/min。(2)冷却面积:A= (10)式中 h-冷却管道壁与冷却介质之间的传热膜系数, -模温与冷却介质之间的平均温差,。 (11)式中:-与冷却水温度有关的物理系数; -冷却水在一定温度下的密度,; -冷却水在圆管中的流速,m/s; d冷却水管的直径,m。查表得,=7.60;=1000; m/s;d=0.015m。则所以 A=(3)冷却管道的孔数: (12)取冷却管道孔数为2。(4)冷却管道的设计:浇口部位是模具上最热的部位,应加强冷却,一般将冷却水的入口设在浇口处,使冷却水先通过浇口处,如下图4所示。图4 冷却回路入口结构模具中选用沟道式冷却及直接在模具或者模板上钻孔铣槽,通入冷却水冷却。型腔的冷却回路选用外接直通式,如图5所示为最简单的外部连接的直通管道布置。用水管接头和橡胶管将模内管道连接成单路或者多路循环。该形式的管道加工方便,适合较浅的矩形型腔,其缺点是外接部分容易损坏。图5模具上的冷却回路(5)型芯冷却回路设计:型芯冷却回路的开设可在型芯上直接钻水道,其结构如下图6。图6 型芯的冷却回路第八章 注射压力、锁模力和安装尺寸校核及注射机的选定8.1注射压力的校核注射机的额定压力即为该机器的最高压力Pmax=150MPa注射成型时候所需的注射压力P。即. (13)式中-安全系数常数=11.3,此处=1.1,。PP的成型注射压力为130MPa。 1301.1 =143Mpa150Mpa,满足要求。所以 注射压力一般塑件的成型注射压力为130MPa。从注射压力可以判断第四章选择的两种注射机都适合。8.2锁模力的校核锁模力的大小主要取决于注射压力和施压方向垂直的制品投影面积,三者必须符合下列的关系才达到锁模的目的。 (14)式中 -锁模力,KN; -注射压力,MPa; -压力损耗系数,一般在0.30.6之间,取0.4; -安全系数,一般在11.3之间,取1.1; -于施压方向垂直的制品投影面积。所以初步选定的两台注射机的最大锁模力分别为5000KN,和8000KN,故SZ40000/800型号的注射机满足要求。8.3 安装尺寸与工艺的设计与校核(1)开模行程的校核:校核时只要使注射机最大开模行程大于模具所需的开模距离,即 S (15)对于单分型面模具,模具所需开模距离为: (16)式中: H1塑件脱模需要的顶出距离,为500mm; H2塑件高度,为560mm。开模行程需要满足:S=500+5680+7=1067mm,初步选定中的SZ2500/500注射机的最大开模行程为850mm1067mm,所以满足要求。注射时间的校核:根据公式 (17)式中: Q-注射量, V-注射速度,所以 (2)保压压力及时间的校核:保压力的大小取决于模具对熔体的静水压力,并与之间的形状、壁厚有关。保压力可稍低于注射压力,取保压压力为50MPa。PP塑件的保压时间约取20s。(3)冷却时间设计为30s。(4)成型周期的估算:根据公式: (18)及一个方凳的注射成型过程为96.5S。8.4 注射机的确定根据注射压力,锁模力以及开模行程的校核,最终确定选取注射机的型号为:SZ4000/800。第九章 成型工艺条件根据前面的设计可以确定方凳的注射成型工艺条件如下表:表4 方凳注射的工艺条件料筒温度() 后段 中段 前段 喷嘴250260220210模具温度()70注射压力(MPa)130注射时间(s)1.5冷却时间(s)30保压时间(s)20注射总周期(s)96.5保压压力(MPa)50熔体温度()240第十章成本及利润核算10.1 方凳的成本(1)原料的价格原料的总价格约为6元。(2)能耗的价格机器的功率为20,如果每天24小时不间断生产,电价为1.5元,每天消耗电价为:=20241.5=720元(3)工资按每人1400元一月,一台机需3人操作,每天工资为:=1400330=140元(4)机器损耗此机器的价格为25万元,假设可用10年,则每天损耗费:=25000010365=68.5元注射机每天生产的凳子数个(5)每个凳子所需的其它成本 (6)塑料方凳的总成本为Y=6+1.0=7元10.2每天的利润注射机每天生产895个方凳,每个方凳的价格为12元,则每天的利润为:L=(127)89572014068.5=3546.5元及一天可以获利3546.5元。第十一章 课程设计总结塑料方凳的设计选用的基体树脂是聚丙烯,并通过加入助剂来使得塑料等达到预期的效果,改善聚丙烯的力学性能,并且可以降低成本,选用注射成型的方式来生产方凳,选用的注射机型号为SZ4000/800,并确定在注射时得各个工艺参数。方凳能承受的载荷条件要达到784N,并能承受40的高温和10的低温,设计洛氏硬度70,弯曲强度45MPa,凳子成型收缩率55 J.m-2,断裂伸长率100-200%。在设计的最后进行了成本和利润的估算,可达到日利润3546.5元。参考文献1张国强.注塑模设计与生产应用. 北京:化学工业出版社 2005;2 周达飞 唐颂超.高分子材料成型加工. 北京:中国轻工业出版社 2010;3 罗河胜.塑料工艺与实用配方. 广东:广东科技出版社 2004。请您删除一下内容,O(_)O谢谢!Many people have the same mixed feelings when planning a trip during Golden Week. With heaps of time, the seven-day Chinese National Day holiday could be the best occasion to enjoy a destination. However, it can also be the easiest way to ruin how you feel about a place and you may become more fatigued after the holiday, due to battling the large crowds. During peak season, a dream about a place can turn to nightmare without careful planning, especially if you travel with children and older people. As most Chinese people will take the holiday to visit domestic tourist destinations, crowds and busy traffic are inevitable at most places. Also to be expected are increasing transport and accommodation prices, with the possibility that there will be no rooms available. It is also common that youllwait in the line for one hour to get a ticket, and another two hours at the site, to only see a tiny bit of the place due to the crowds. Last year, 428 million tourists traveled in China over the week-long holiday in October. Traveling during this period is a matter that needs thorough preparation. If you are short on time to plan the upcoming Golden Week it may not be a bad idea to avoid some of the most crowded places for now. There is always a place so fascinating that everyone yearns for. Arxan is a place like this. The beauty of Arxan is everlasting regardless of the changing of four seasons. Bestowed by nature, its spectacular seasonal landscape and mountains are just beyond word. Arxan is a crucial destination for the recommended travelling route, China Inner Mongolia Arxan Hailar Manzhouli. It is also the joint of the four prairies across the Sino-Mongolian border, where people gravitate towards the exotic atmosphere mixed with Chinese, Russian, and Mongolia elements. As a historic site for the Yitian Battle, Arxan still embodies the spirit of Genghis Khan. Walking into Arxan, you will be amazed by a kaleidoscope of gorgeous colors all the year round - the Spring azaleas blooming red in the snow, the Summer sea wavering blue in the breeze, the Autumn leaves painted in yellow covering volcanic traces, and the Winter woods shining white on the vast alpine snowscape. Hinggan League Arxan city is situated in the far eastern area of Inner Mongolia Autonomous Region. Its full name Haren Arxan means hot holy water in the Mongolian language. Arxan is a tourism city in the northern frontier with a blend of large forest, grand prairies, vast snowfield, heaven lake cluster, thermium, as well as volcanic cluster. It is a rare and unique ecotourism base filled with healthy sunshine, clean air and unspoiled green. Nestled close to the countrys largest virgin forest, and known for its spring and ecological environment, Arxan is marveled at by many tourists as the purest land on earth. You cannot miss out the Autumn of Arxan. It is definitely the best with brightly-colored scenery full of emotions. Autumn in the northern part of the country comes earlier than the South. A September rain followed by the footprints of Autumn brings more colors to the once emerald green mountain and blooming grassland. Shutterbugs flock to see for themselves the marvel of splendid colors around the mountains and waters, many of whom have travel a long distance and even camp here only to capture a moment of the nature wonder. The silver birch turns golden, while the larch is still proudly green. You will find yourself drowned in the intoxicating red of the wild fruits as well as the glamour of flowers in full blown. And your heart will be lingering on the woods as its time for the wild fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If itrains heavily on Saturday night, some elderly Chinese will say it is because Zhinu, or the Weaving Maid, is crying on the day she met her husband Niulang, or the Cowherd, on the Milky Way. Most Chinese remember being told this romantic tragedy when they were children on Qixi, or the Seventh Night Festival, which falls on the seventh day of the seventh lunar month, which is usually in early August. This year it falls on Saturday, August 2. Folklore Story As the story goes, once there was a cowherd, Niulang, who lived with his elder brother and sister-in-law. But she disliked and abused him, and the boy was forced to leave home with only an old cow for company. The cow, however, was a former god who had violated imperial rules and was sent to earth in bovine form. One day the cow led Niulang to a lake where fairies took a bath on earth. Among them was Zhinu, the most beautiful fairy and a skilled seamstress. The two fell in love at first sight and were soon married. They had a son and daughter and their happy life was held up as an example for hundreds of years in China. Yet in the eyes of the Jade Emperor, the Supreme Deity in Taoism, marriage between a mortal and fairy was strictly forbidden. He ordered the heaven troop to catch Zhinu back. Niulang grew desperate when he discovered Zhinu had been taken back to heaven. Driven by Niulangs misery, the cow told him to turn its hide into a pair of shoes after it died. The magic shoes whisked Niulang, who carried his two children in baskets strung from a shoulder pole, off on a chase after the empress. The pursuit enraged the empress, who took her hairpin and slashed it across the sky creating the Milky Way which separated husband from wife. But all was not lost as magpies, moved by their love and devotion, formed a bridge across the Milky Way to reunite the family. Even the Jade Emperor was touched, and allowed Niulang and Zhinu to meet once a year on the seventh night of the seventh month. This is how Qixi came to be. The festival can be traced back to the Han Dynasty (206 BC-AD 220). Traditionally, people would look up at the sky and find a bright star in the constellation Aquila as well as the star Vega, which are identified as Niulang and Zhinu. The two stars shine on opposite sides of the Milky Way. Customs In bygone days, Qixi was not only a special day for lovers, but also for girls. It is also known as the Begging for Skills Festival or Daughters Festival. In this day,

温馨提示

  • 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
  • 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
  • 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
  • 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
  • 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
  • 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
  • 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

评论

0/150

提交评论