Papers by Keyword: Process Characteristics

Abstract: The hot-rolled strip skin-pass mill is the important technological equipment of finishing process in the hot rolling plant, and its role is to apply a slight thickness reduction of approximately 1% - 4% to the finished products cooled to room temperature to repair flatness defects and improve the surface quality and mechanical properties. In this study, the initial flat roll contours were optimized to solve some problems such as the serious and non-uniform wear of work rolls and the poor shape control abilities of the strip. A three-dimensional rolls–strip coupling model of hot-rolled strip skin-pass mill was established using the nonlinear finite element software ABAQUS. The effects of the roll contours on the contact pressure between rolls and the control effect of bending forces were analyzed, and a variable contact-length backup roll (VCR) contour configured with a positive crown contour for work rolls was proposed. Compared with the initial flat roll contours, the average replacement cycle of work rolls for the optimized roll contours increased from 465.4 tons to 701.3 tons, the non-uniform wear amount was reduced by nearly 15%, and the adjustment ratio of the negative bending forces decreased from -100% to -40% by industrial experiments in the 1580 mm single-stand four-high hot-rolled strip skin-pass mill.

Abstract: Nowadays, plastic injection molding is widely used in the production of very complex parts and it enables to produce numerous parts within one cycle. Molding conditions or process parameters are crucial for productivity and quality of desired products. This research aims to investigate the state-of-the-art approach to find optimal parameters characteristics in plastic injection molding process. Fill time, average velocity, pressure, clamp force, cooling time and volumetric shrinkages are selected as process parameters in this research. Nokia 6680 model is used for revealing process optimization. Two case studies based on two plates and three plate moulding layout are conducted to suggest the plastic injection mold optimization process. The process parameters of two proposed layouts are compared based on Mold flow Plastics Insight (MPI) analysis results. Result show that three plate moulding satisfy not only the process quality but also the product quality characteristics in this injection moulding process.

Abstract: The MID technology offers a high potential for the development of innovative integrated product solutions. The integration of mechanical and electronic functions on a spatial circuit board allows the realization of modules with a high functional density and a significant degree of miniaturization. MID components are spatial injection molded parts, with their surface selectively patterned and metalized. The conventional production of MID applications by an injection molding process is time consuming and expensive. Therefore, the efforts of industry and research show the significance of MID prototyping. Our objective was to develop process overviews and matching sequences for the methodological-assisted prototyping within our MID-Laboratory (MIDLab). First of all, we developed process overviews for any suitable process operations in accordance to the MID reference process. To enable a methodological approach in the production planning, essential information has been summarized in characteristics. The characteristics include a short description of the process and its unique features and a summary of the advantages and disadvantages compared to alternative methods. In addition, the compatibility of subsequent process steps, if limited or restricted, is illustrated. Afterwards, these process steps were combined to production sequences with a focus on costs, benefits and house production. Based on the requirements of the prototype, two scenarios have been developed, covering a wide spectrum of possibilities. In both sequences emphasis has been placed on cost-optimal combinations with a high house production rate. The validation of the results was carried out by two application examples. For this reason demonstrators were designed. On the basis of these modules, the results of the developed process chains were validated.

Abstract: The performance of two-phase anaerobic in a laboratory-scale operating on traditional Chinese pharmaceutical industry wastewater at various hydraulic retention times was investigated. The wastewater with high pollutant concentration in reactor designed based on two-phase anaerobic principles was analyzed with GC-MS. The effect of controlling the pH of the methanogonic phase of traditional Chinese pharmaceutical industry wastewater digestion on the biogas production rate and pollution potential reduction was also investigated. The reactor was designed to act as a liquid-solid separator, in order to maximize the microbial mass in it, and was operated at different hydraulic retention times. It operated as a two-phase reactor when the pH of the wastewater was controlled in the methanogenic phase. The results of experiment indicate that acidifier discomposes compounds composed of big molecule were degraded into small acid molecule which is more subject to biochemical treatment, and after the final treatment of reactor producing methane, species and contents of compound contained in treated wastewater are obviously reduced.

Abstract: Traditional fire detection technologies usually measure the smoke particles or the temperature increase resulted from fire. However in the early stage of fire, few particles and low heat are generated. Current fire algorithms is based on comparing the fire variables with a given threshold value, the transient sampled values are often affected by some stochastic disturbances. Consequently current methods are hardly alarm fire fleetly and reliably and often give false or failing alarm. A new fire detecting technology was presented based on early fire process signature and fuzzy clustering algorithm. The process eigenvector is made up of CO concentration in detected environment as well as its increasing rate and acceleration. The eigenvectors are divided into two categories of real fire and non-fire, the two cluster centers are obtained by using fuzzy clustering analysis. According to threshold membership principle, the real fire sources can be distinguished from non-fire sources successfully. The result of experiments has shown that the presented technology is feasible for early fire detecting with lower rate of false and failing alarm, and give fire alarm much early than any other traditional method.

Abstract: At present, crankshafts are finished mostly by abrasive cloth and manual steel brush, which is not ideal on finishing quality, efficiency and cost, especially cleanness degree does not meet design and use request. So horizontal spindle barrel finishing has been developed. Based on its finishing theory, process characteristics are key factors affecting the finishing effect, especially finishing uniformity. Process characteristics of motion parameters, finishing depth, finishing time, etc. are analyzed, and reasonable parameters are defined. It provides basis for industry application of this process.