锥形双螺杆专业应用程序的开发及应用

CAD二次开发成果在塑料模具上已经得到了普遍应用。融合新的设计理念，针对锥形双螺杆的设计进行AutoCAD二次开发及应用。     

Study on the thermoplastic vulcanizate using ultrasonically treated rubber powder

Nowadays, waste EPDM (ethylene propylene diene monomer) increasingly has been causing significant environmental problems with increasing numbers of vehicles. From the perspective of the environment and economics, recycling is the best method to treat waste materials. This study investigated waste EPDM/PP (polypropylene) blends with waste EPDM. Waste EPDM powders were treated ultrasonically, which physically modifies the rubber particles to confer good mechanical properties. Also investigated were the relevance of the mass percentage of the dispersed phase, the influence of the geometry and rotation speeds of the screw used in extrusion, and the melting temperature of PP materials on the morphology and mechanical properties of the blend. The purpose of this study was to develop a valuable thermoplastic elastomer from waste EPDM. This study concentrated on determining the optimum conditions for producing a blend by extrusion, including parameters of screw geometry, screw rotational speed, and operating temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2503–2507, 2003     

Extrusion of ultrahigh molecular weight polyethylene under ultrasonic vibration field

The effects of polypropylene (PP) and ultrasonic irradiation on the processing and mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE) are studied. The results show that PP can effectively improve the fluidity and mechanical properties of UHMWPE. The Izod notched impact strength increases from 92 kJ/m² for pure UHMWPE to 109.2 kJ/m² for the blend of UHMWPE with 10 wt % PP. The Young's modulus increases from 528 MPa for pure UHMWPE to 1128 MPa when 25 wt % PP is contained in the blend, and the yield strength also rises when PP is added. The application of ultrasonic vibrations during extrusion can prominently decrease the die pressure and apparent viscosity of the melt, thus increasing the output of extrudate. An appropriate ultrasonic intensity and irradiation time can further promote the mechanical properties, while an overdose of irradiation destroys them. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2628–2632, 2003     

The Plasticating Sequence in Barrier Extrusion Screws Part II: Experimental Assessment

A modular laboratorial single screw extruder was used to perform screw pulling experiments and generate data on the development of plasticating of two polymers along the axis of a Maillefer barrier screw. The effects of the presence of the barrier (by comparison with an equivalent conventional 3-zone screw), of its geometrical parameters and of operating conditions were investigated and compared to the predictions provided by a previously developed computational model. Although the small size of the extruder influenced solids conveying and induced premature and quick melting, the two sets of data were generally in satisfactory agreement.     

Application of Ultrasound for Oil Separation and Recovery of Palm Oil

This work investigated whether ultrasound treatment could improve the oil recovery from the extract obtained from pressed oil palm mesocarp. Oil recoverable after subjecting two process streams from palm oil milling operations to ultrasound were compared to that obtained from corresponding samples without ultrasound treatment. The process streams examined were (i) the ex-screw press feed into the vertical clarification tank and (ii) the underflow sludge from the clarification tank. Oil recoverable was taken as the sum of decantable oil obtained after a gravity settling process at 85 °C for 1 h (skimmed oil) and oil released from the remaining colloidal dispersion after centrifugation at 1,000 g (centrifuged oil). Oil recoverable was dependent on the ultrasound treatment applied, type of transducer used and the feed stream. Increased recoverable oil was obtained by applying low frequency ultrasound (20 kHz) to the ex-screw press feed using a long rod radial sonotrode system but recoverable oil was decreased when a short single step cascade focused sonotrode system was used. High frequency ultrasound (400 + 1,600 kHz) increased recoverable oil from both process streams. Applying sequential low and high frequency ultrasound increased recoverable oil from the ex-screw press feed but decreased that from the underflow sludge. The use of high frequency ultrasound for improving oil recovery is a significant advance for palm oil milling operations.     

螺压推进剂成型工艺过程安全性分析

为提高螺压推进剂成型工艺过程的安全性,从剪切流动、绝热压缩和过热分解等视角,对推进剂在单螺杆压伸成型工艺过程中发生危险的可能性进行论述。系统地分析了药料在螺杆和模具内的流动状态,通过模拟实验,研究了推进剂在压伸过程中的热分解(着火)温度,通过实验数据分析了热分解的原因。结果表明:在药料剪切强度下降的情况下,固体床的断裂将意味着压伸的失败;在排气不畅的情况下,压伸过程的断料有可能形成绝热压缩而引发严重后果。     

Laboratory modular instrumented single screw extruder for optimisation of polymer processing

Abstract

A laboratory fully modular instrumented single screw extruder designed to gather information on the development along its axis of temperature, mixing, chemical conversion and/or morphology development of a given material is presented. Some of its capabilities are utilised to study the effect of operating conditions and of screw geometry, including conventional versus barrier profiles, on the evolution of the plasticating sequence of a low density polyethylene. Melting of an immiscible polymer blend (polyamide 6/polypropylene) is also investigated and a specific melting mechanism is proposed.     

TPU生产工艺路线的比较与选择

比较并分析了热塑性聚氨酯弹性体（TPU）双螺杆法与传送带法生产工艺之间的差别.     

乳化炸药包装机中双螺泵的研制

本文介绍了用于乳化炸药包装机中物料传输的双螺杆泵的设计.在设计的过程中,参照了德国Ploy-elip公司的自动灌装系统,利用UG对核心构件双螺杆曲面进行光滑拟合,并对整体数据进行三维造型.     

双螺杆挤出丁苯透明抗冲树脂溶液脱挥工艺

将质量分数为20．00％的丁苯透明抗冲树脂溶液经浓缩器提浓至质量分数不小于30．00％后,送入同向啮合式双螺杆挤出机,在多段真空状态下脱除溶剂,研究了双螺杆挤出脱挥工艺中的温度、真空度、停留时间和螺杆转速工艺务件,并与湿法凝聚工艺进行了产品分子参数和能耗对比。结果表明,双螺杆挤出脱除溶剂工艺适用于丁苯透明抗冲树脂溶液脱除溶剂,其能耗远低于湿法凝聚,所得产品的性能与国外同类产品基本相当。