GMT汽车挡泥板的成型工艺研究

采用玻璃纤维增强聚丙烯片材和流动模塑成型工艺试制汽车挡泥板。通过模具的合理设计,并设定了压力、温度、时间等成型工艺参数:模塑片材在220℃中预热10 min;成型压力15 MPa,保压1 min;模具工作温度120℃。压制出的产品具有良好的表面质量和优异的力学性能,制品合格率>95%,满足设计要求。     

FRTP片材冲压成型技术的近况及市场预测

冲压成型工艺是利用FRTP片材为原科(坯料)加工制品的高速压模工艺,也是熔融流动成型工艺(a melt forming process)——熔融状片材投入模内,在高压下快速闭合上下模具,使物料充满模腔,最终制成制品。其坯料利用率为100％,系净模塑工艺(a net molding process)。分析一下当今FRTP工艺,可初步看出该冲压工艺较为先进,因而前景广阔。一、冲压系统冲压系统(见图1)的主要设备有片材加热炉冲压模具、冲压机和模温控制仪。     

双片材热成型技术

在英国伯明翰举办的Ｉｎｔｅｒｐｌａｓ’99上,英国Ｄｕｃａｐｌａｓｔ公司示了其开发的双片材热成型技术。两种热塑性片材通过真空成型,熔融粘接在一起,形成空心结构的产品,可用于材料加工、农业、海洋、通讯、国防、汽车和许多其它领域。双片材热成型工艺是真空成型技术的主要领域,工艺包括对两种热塑性片材的加热,将其放置在两个分离的模具表面,在模具和原材料之间的空气被排放,形成一个真空。大气压力将片材压入模具,与模具表面接触而成型。精确地控制两个模具的温度,在压力作用下两块片材粘接在一起。在这种工艺中,所设计的模具面应满…     

空心玻璃微珠复合聚氨酯泡沫的模塑成型收缩率

研究了用空心玻璃微珠复合聚氨酯泡沫塑料制成厚度不同、形状不同、结构不同的制品时模型成型的收缩率，以及在模塑成型过程中，熟化温度、熟化时间和熟化后在模具内保持的时间对模塑成型收缩率的影响。结果表明，制品模塑成型收缩率随着厚度的增加而增大；加入金属嵌件后可较大程度地限制制品收缩；当熟化温度高于100℃时，随着熟化温度的升高，制品收缩率增大。     

PET片材热成型技术

介绍目前我国PET片材热成型加工技术中成型设备、加工原理、模具制作、加工工艺，为PET片材加工业的发展及开发应用提供参考。     

气辅注射模塑制件和模具的设计特点及原则

本文介绍了一种新型成型工艺－气辅注射模塑制件和模具的设计特点及一般原则，并通过与传统注射模塑制件和模具设计的比较，阐述了气辅注射模塑与传统注射模型在制件和模具设计上的差别以及气辅注射模塑的优越性。     

旋转模塑工业中新原料与新技术的应用

本文介绍了近年来在旋转模塑工业中出现的一些新原料和新技术包括模具制造新技术、成型工艺新技术，它们的出现使旋转模塑工艺的竞争力不断提高。     

汽车冷却风扇面罩热固性压缩模设计

针对风扇面罩SMC热固性塑料压缩成型的需要,设计了其模一模一腔两板模结构热固性压缩成型模具,模具由成型件、加热系统、顶出系统等机构件组成;模具的加料方式采用机械手条料加料方式,并对条料进行分割均布以保证塑件成型的饱满性;模具上、下模温度控制采用油温控制,模腔成型工艺参数为:温度控制在150℃,成型压力为41 MPa,成型时间1. 2 min/mm,脱模取件温度为80℃;模具的顶出机构采用4个油缸驱动顶出板及顶针平衡顶出。模具结构简单,布局合理,便于制造和生产。     

滚塑成型工艺与设备发展状况

1 滚塑成型工艺及其优势 滚塑是中空塑料制品成型的一种工艺方法，又称旋转成型、旋转模塑或回转成型。滚塑过程是将塑料粉末加入模具中，然后加热模具并使之沿相互垂直的两根轴连续旋转，模具内树脂在重力和热量的作用下逐渐均匀地涂布、熔融黏附于模具内表面上，从而形成所需要的形状，然后冷却模具，脱模得到制品。     

GMT片材的制造与应用技术 Ⅳ GMT制品成型技术

简要介绍了GMT制品的成型技术。成型GMT制品合理的坯料设计和铺设方式取决于片材所用的基体和玻纤毡特点以及制品形状,坯料铺设推荐层叠式。模压较佳的工艺条件是:片材预热后温度195-220℃,模温60-90℃,模腔压力10-25MPa,终端合模速度15-30mm/s。     

纵论注射成型技术

以注射成型技术在橡胶行业的发展现状为依据,从工作原理、生产工艺、产品质量、生产效率等几个方面着手,对模压成型技术和注射成型技术进行了比较,阐述了注射成型技术的优越性。同时,针对推广注射成型技术遇到的困难,提出了注射成型技术在橡胶行业的推广过程中所需要解决的一系列问题。     

Real‐time ultrasonic monitoring of the injection‐molding process

In this study, a noninvasive and nondestructive ultrasonic technique has been used to monitor the polymer injection‐molding process in an attempt to establish a fundamental understanding of the processing/morphology/ultrasonic signal relationships. The ultrasonic technique not only can provide information on solidification affected by various temperatures and pressures but also can reflect the evolution of the crystal morphology and phase morphology of polymer blends. In addition, the periodic vibration of the dynamic‐packing injection‐molding process, in which the melt is forced to move repeatedly in a chamber by two pistons that move reversibly with the same frequency as the solidification progressively occurs from the mold wall to the molding core part, can also be monitored with the ultrasonic velocity and attenuation. Our results indicate that the ultrasonic technique is sensitive and promising for the real‐time monitoring of the injection‐molding process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

聚醚酰亚胺成型技术探讨

阐述了聚醚酰亚胺的性能、工艺特性、成型设备、制品和模具的设计,以及注射成型的要点和注意事项。     

Injection Molding Nanoscale Features with the Aid of Induction Heating

During injection molding of micron or submicron scale features, incomplete filling frequently occurs, resulting from premature freezing of the polymer melt in contact with a cold mold. In order to overcome the filling difficulty without increasing the total cycle time, the mold surface temperature was raised rapidly by induction heating. A prototype mold insert with cooling channels was fabricated and integrated with a nickel stamp having nanoscale-grating structures. The nickel stamp surface was successfully heated from 25 to 258°C in 2.7 sec. Four different mold surface temperatures, 100, 150, 200 and 250°C, were tested to determine if the nanograting structures can be replicated with an optical quality cyclic olefin copolymer. Experimental results indicate that the nanocavities were successfully filled when the surface temperature reached 250°C, but mold release caused drag damages on the nanogratings. Further, coupled thermoelectromagnetic analyses were carried out to simulate the induction heating process of the nanostructured mold insert. The predicted surface temperature responses in general agree with the experimental ones and the simulation model can be used in the further development of process control and mold design in micro/nano molding.     

熔体振动成型技术的应用

简要介绍了熔体振动成型技术在注射、挤出、吹塑等方面的应用。通过大量的实验表明 ,熔体振动成型可提高生产率、质量及力学等方面的性能     

模糊PID法在塑料成型条件优化中的应用

针对比例–积分–微分(PID)方法在塑料成型加工仿真模拟中存在一定的超调和震荡现象的问题,利用模糊控制对工艺参数改变的反应不太敏感的特点,将两种方法进行联用,可在一定程度上弥补PID方法的超调和震荡现象,从而实现塑料加工过程快速高效的控制。为此,综述了模糊PID控制方法在塑料注射成型、挤出成型、吹塑成型、压延成型等成型方法中的应用,并着重阐述了其在注塑机料筒温度控制和电液系统控制方面的应用。     

Analysis of the influence of the injection molding process on the crystallization kinetics of a HDPE

Thermal analyses of microparts in high density polyethylene (HDPE) have shown that the specific processing conditions used in microinjection molding have irreversible consequences on the polymer morphology. This result has been demonstrated with the analysis of the non‐isothermal crystallization behavior of a HDPE with different thermal histories. The evolution of the absolute crystallinity has been analyzed with a relevant model able to separate the primary and secondary mechanisms all over the crystallization duration. This model has emphasized that the evolution of the primary crystallinity with time is different for the microparts compared to the conventional objects. These differences were attributed to variations of the crystallization mechanisms, especially within the nucleation phase, where a persistent melt memory effect of the former chains orientation/extension was assumed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44239.     

精神注射成型影响因素分析探讨

从塑料材料、模具设计与制造、成型工艺和成型设备等方面对影响精神注射成型的因素进行了讨论，并给出了相关的解决办法。     

气体辅助注射技术及其他介质辅助成型最新进展

概括地介绍了传统气体辅助注射技术的工艺及它的优缺点。并详细地介绍了气辅注射过程中的一些改进方法,如:外部气辅注射、局部气辅注射、振动气辅注射等,及运用其他介质的一些辅助成型方法,如:液体辅助注射(水辅注射)等新技术。