Advances in Research of Molded Pulp for Food Packaging

The molded pulp,a product of three-dimensional papermaking technology,is environmentally friendly and has a low environmental impact due to its ability to decompose quickly in the natural environment after disposal.The application of molded pulp for food packaging can replace or reduce the use of plastic food packaging.Researchers extract fibers from plants for the production of safe and hygienic molded pulp for food packaging,and they also study and enhance the qualities of molded pulp to broaden its use in the food industry.This paper reviews the sources and varieties of plant fiber used in molded pulp for food packaging,as well as research on the improvement and optimization of the performance of molded pulp products.Additionally,issues with molded pulp’s actual use for food packaging are reviewed,along with the potential for future research.This work can serve as a reference for molded pulp applications and research in the food industry in the future.

Rheological characteristics of injection molded titanium alloys powder

Ti-6Al-4V alloy powder was taken as raw material. 60%（mass fraction） paraffin, 35%low density polyethylene and 5%stearic acid were employed as binders to prepare injection feedstocks. Capillary rheometer was adopted to determine the rheological parameters and to analyze the rheological properties of the feedstocks at different milling time, powder loading and temperature. It is indicated through the results that the viscosity increases and the value of n decreases with the increase of milling time. The more the powder loading is, the higher the viscosity is. The empirical formula on the relationship between the viscosity and the powder loading is： ηr=η/ηb=A（1-Ф/Фmax）/^- m . The value m is calculated as 0.33. The flow activation energy Ea decreases with the increase of shear rate.

Analysis of Mechanical Properties of Injection Molded Short Glass Fibre (SGF)/Calcite/ABS Composites

Acrylonitrile-butadiene-Styrene (ABS), with and without calcium carbonate (calcite) particles,was used as the matrix for reinforcement with as-received short-glass fibres (were originallytreated by the manufacturer) and sized short-glass fibres with two amino-silane coupling agents.The calcite particle content is 0, 11.7 and 23.5 vol. pct for the matrices. The glass fiber contentis 0, 10 and 15 vol. pct. The matrix materials and corresponding composites were compoundedusing a twin screw extruder and dumbbell-shaped tensile bars were prepared with an injectionmolding process. The tensile and flexural properties as well as the unnotched and notchedCharpy impact energies of short glass fibre/calcite/ABS composites were studied in this paper.The effects of fibres, fibre surface treatments and particles on these mechanical properties ofthe composites were discussed in detail. An importarit information was obtained, which is thatthe tensile and flexural strengths of hybrid SGF/calcite/ABS composites are the same as thoseof corresponding fibre composites when the ratio of the interfacial adhesion strength betweenparticles and matrix to that between fibres and matrix is higher than certain value. otherwise theformer are lower than the latter.

Evolution of microstructure and dimension of as-molded parts during thermal removal process of wax-based MIM binder

The evolution of the microstructure and the dimension of as molded parts were studied on the basis of the thermogravimetric analysis of wax based MIM binder. The results show that the binder removal speeds are different in different temperature ranges during binder removal process. The evolution of the microstructure of as molded parts during binder removal process clearly showed the initiation and formation of connected pore structure, which is the removal channel of the binder. The as molded parts almost continuously shrank through binder removal process, except an expansion stage during 320～440 ℃, which is the dissolution expansion effect due to the dissolution of V PW in the polymer melt. [

美国吹塑商Blow Molded添加新设备

Blow Molded Specialties购买了一台新的格雷厄姆Engineering Hercules储料缸式机头吹塑机,从而提高其处理复杂燃料和液压柜配件和驾驶室组件的能力。该机器的射出量为50磅,将于2017年1月正式投入使用。公司销售部副总裁Michael Thompson在一次电话采访中表示：＂我们购买这个设备的第一个原因是公司在持续增长,第二个原因是我们增添了很多新的设备,帮助我们获得了更多的业务,也使得生产更加有效率。＂这标志着该公司连续两年增加关键器械,

T01067∗Series Fuel Pump Pulp Molded Package Dynamic Drop Simulation

In this paper,combined with the actual situation encountered in the process of product transportation,the finite element analysis software ANSYS/LS-DYNA was used to simulate the dynamic drop process of the buffer packaging structure of T01067∗series fuel pump,and the simulation results were analyzed,and a conclusion was drawn.According to the fuel pump weight calculation buffer material thickness,according to the product size and structure design of the pulp molded cushion structure,simulation of static cushioning performance,and dynamic drop simulation,for the subsequent structural optimization cost reduction to provide early warning[1,2].Check the simulation production cost,reducemany times a large number of experiments and time,structure is ideal type prediction,find out the ideal optimization total,physical test,further optimization and improvement[3].

Warpage prediction of the injection-molded strip-like plastic parts

For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the warpage be- cause of their special shape. A new solution was suggested in this work. The strip-like plastic part was regarded as a little-curved beam macrnscopically, and was divided into a few one-dimensional elements. On the section of each elemental node location, two-dimensional thermal finite element analysis was made to obtain the non- uniform thermal stress caused by the time difference of the solidification of the plastic melt in the mold. The stress relaxation, or equivalently, strain creep was dealt with by using a special computing model. On the bases of in-mold elastic stress, the final bending moment to the beam was obtained and the warpage was predict- ed in good a^reement with practical cases.

INJECTION MOLDED TUNGSTEN HEAVY ALLOY

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STRESS ANALYSIS OF INJECTION MOLDED PARTS IN POST-FILLING STAGE

The linear isothermo-viscoelastic constitutive equation is established according to the principle of viscoelastic mechanics. Given the boundary conditions of the temperature field, the linear thermo-viscoelastic constitutive equation is established acording to the analysis of the thermorheologically simple. The stress analysis model is constructed on the base of some reasonable hypotheses which consider the restraint conditions of mold and the characteristics of injection molding in the post-filling stage. The mathematical model is calculated by the finite difference method. The results can help to predict the warpage of plastic products.

Influence of binder composition on the rheological behavior of injection-molded microsized SiC suspensions

The influence of four kinds of binders consisting of paraffin wax （PW）, random-polypropylene （RPP）, high-density polyethylene （HDPE）, and stearic acid （SA） on the theological behavior of injection-molded SiC feedstocks was investigated over a temperature range of 150℃ to 180℃ and a shear rate range of 4 s^-1 to 1259 s^^-1. The results showed that all the feedstocks exhibited pseudoplastic flow behavior. The wax-based binder of multipolymer components （PW-RPP-HDPE） exhibited better comprehensive rheological properties compared with the binder of monopolymer components （PW-RPP or PW-HDPE）. The addition of 5wt% SA to the binder could reduce the viscosity of the feedstock but enhance the rheological stability by improving the wettability between the binder and the SiC powder. The binder of 65wt% PW ＋ 15wt% HDPE ＋ 15wt% RPP ＋ 5wt% SA was found to be a better binder for microsized SiC injection molding.

Effects of heat treatment on the properties of powder injection molded AlN ceramics

The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride（AlN） ceramics were investigated.The AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis（SHS） and compacts were fabricated by employing powder injection molding technique.The polymer-wax binder consisted of 60 wt.% paraffin wax（PW）,35 wt.% polypropylene（PP）,and 5 wt.% stearic acid（SA）.After the removal of binder,specimens were sintered at 1850°С in nitrogen atmosphere under atmospheric pressure.To improve the thermal conductivity,sintered samples were reheated.The result reveals that the heat-treatment atmosphere has significant effect on the properties and secondary phase of AlN ceramics.The thermal conductivity and density of AlN ceramics reheated in nitrogen gas are 180 W·m^-1·K^-1 and 3.28 g·cm^-3 and the secondary phase is yttrium aluminate.For the sample reheated in reducing nitrogen atmosphere with carbon,the thermal conductivity and density are 173 W·m^-1·K^-1 and 3.23 g·cm^-3,respectively,and the secondary phase is YN.

Shape retention of injection molded stainless steel compacts

The effects of the binder composition, the powder loading, the thermal properties of feedstocks, and the injection molding parameters on the compact shape retention for metal injection molding 17-4PH stainless steel were investigated. The high-density polyethylene is more effective than ethylene vinyl acetate as a second component of the wax-based binder to retain compact shape due to its higher pyrolytic temperature and less heat of fusion. The compact distortion decreases with increasing the powder loading, molding pressure and molding temperature. There exists an optimal process combination including the powder loading of 68%, molding pressure of 120MPa and molding temperature of 150℃. Under this process condition, the percentage of distorted compacts is the lowest.

Reducing Refractive Index Variations in Compression Molded Lenses by Annealing

Compression molding of glass optics is gradually becoming a viable fabrication technique for high precision optical lenses. However, refractive index variation was observed in compression molded glass lenses, which would contribute to image quality degradation. In this research, annealing experiments were applied to control the refractive index variation in molded glass lenses. The refractive index variations pre and post annealing experiment in molded lenses were measured by an experiment setup based on Mach-Zehnder interferometer. The experimental results showed that the refractive index variation can be controlled providing that a proper cooling process is applied during cooling.

Experimental Study of Shrinkage Displacements of Points on Injection Molded Parts

The existing research on shrinkage of the injection molded plastic part mainly focuses on various shrinkage ratios of the part dimensions,and the relevant experimental studies belong to mere dimension measurement after demoulding.Obviously,measuring after the plastic part is demoulded from the cavity can not offer shrinkage displacements of points on the plastic part.However,shrinkage displacements of points on an injection molded plastic part are essential for exposing the inner relation among shrinkage ratios of various dimensions of the part.So visualization of the in-mold plastic part which can indicate the location relationship between the part and the cavity is needed.In this paper,a visual injection mold was fabricated by adopting the half mold structure and light transmission manner.With the visual mold,in-mold shrinkage images of injection molded plastic parts were photographed after the plastic part stayed in the injection mold for 24 h.By means of digital image processing of the in-mold shrinkage images,the experimental data of shrinkage displacements of points on injection molded parts were researched.From the experimental data,it is found that shrinkage directions of points on an injection molded part are related with both positions of the gate and of the part centroid,and either the gate or the centroid will exert more influence on the shrinkage direction of some point which is closer.Furthermore,some point at the later filled area has more shrinkage distance than the point at the earlier filled area.Combination of shrinkage directions and shrinkage distances of points on an injection molded part determine shrinkage ratios for various dimensions of the part,and shrinkage directions are more influential to shrinkage ratios of dimensions.This experimental research of shrinkage displacements offers a unique approach to understand the shrinkage principles of injection molded parts.

EFFECT OF MELT TEMPERATURE ON THE PHASE MORPHOLOGY,THERMAL BEHAVIOR AND MECHANICAL PROPERTIES OF INJECTION-MOLDED PP/LLDPE BLENDS

The phase morphology and thermal behavior of various isotactic polypropylene （PP）/linear low density polyethylene （LLDPE） blends were investigated with aid of scanning electron microscopy （SEM） and differential scanning calorimetry （DSC）, respectively. The effect of barrel （melt） temperature on the morphology, thermal behavior and the resultant mechanical properties of the injection molded bars was the research focus, and the influence of LLDPE composition was also taken into account. It was found that the mechanical properties, especially the tensile ductility and the impact strength, were greatly affected by the processing temperature. The samples obtained at low temperatures had the highest elongation at break and impact strength, while those molded at high temperatures had the poorest toughness. Two reasons were responsible for that： first, the phase size in the samples increased with the processing temperature; second, possible orientation existed in the samples obtained at low processing temperatures.

Manufacturing of Injection-Molded NdFeB Magnet with (BH)max111 kJ · m-3

The bonded NdFeB magnets prepared by injection molding meet with the development tendency of the magnet in small volume, light weight and high performance ,and have a good prospect.In this paper, a modified nylonbased binder was developed for powder injection molding of NdFeB bonded magnets.The effects of pretreatment of NdFeB anisotropic magnetic powder produced with HDDR processing on the anti-oxidation behaviors of powder and the final magnetic properties of the molded bonded magnets were studied.The optimal powder loading of 65 vol% was achieved with the modified binder.It was found that the properties of the bonded magnets were mainly affected by the powder surface pretreatment and the intensity of the applied alignment magnetic field during injection molding for a certain powder.Bonded magnets with remanence of 0.820 T, intrinsic coercivity of 1140.3 kA· m-1 and maximum energy product of 111 kJ · m-3 were produced with the optimal processing.

Flowing simulation of injection molded parts with micro-channel

In the micro-molding of component with a micro-sized channel, the ability for polymer melt to flowing into the micro-channel in a macro-sized part is a big challenge. The multidimensional flow behaviors are included in the injection molding the macro-component with a micro-channel. In this case, a simplified model is used to analyze the flow behaviors of the macro-sized part within a micro-channel. The flow behaviors in the macro-cavity are estimated by using the finite element and finite difference methods. The influence of the injection rate, micro-channel size, heat transfer coefficient, and mold temperature on the flowing distance is investigated based on the non-isothermal analytic method. The results show that an increase in the radius of the micro-channel and mold temperature can improve effectively the flowing distance in the micro-channel.

Sintering products molded by injecting ceramic and metal powders

The injection molding products with different volume ratios of ZrO2 ceramic powder to 316L stainless steel powder were prepared. Properties and structure of the products were characterized by X-ray diffraction（XRD）, scanning electron microscope（SEM） and transmission electron microscope （TEM）. The results show that the compressive stress exists in the products and the bend strength reaches 300MPa. ZrO2 phase and stainless steel phase are uniform in samples. The toughness of ceramic increases with the increasing the content of stainless steel. Through TEM study of the interface, some crystalline orientation relationships are determined.

Effect of sintering parameters on powder injection molded Ti(C, N)-based cermets

Effect of two-stage sintering parameters such as heating rate, top sintering temperature and holding time, sintering temperature and holding time at the second stage on relative density, transverse rupture strength(TRS) and microstructures of powder injection molded Ti(C, N)-based cermets were investigated, by means of Archimedes’s method, three-point bending test and micrographic analysis. The results show that the optimum sintering cycle for powder injection molded Ti(C, N)-based cermets comprises rapid heating (10℃/min) at low temperatures, slow heating (5℃/min) at intermediate temperatures, holding at the highest sintering temperature (1420℃) for a short time (10min), and holding at the second stage (1360℃) for a longer time (6h) to avoid grain coarsening, and that its TRS reaches 624MPa, and there are little pores in their microstructures.

Influence of the Process of Worker on the Mechanical Properties of Carbon Fiber Reinforced Plastic Molded by Autoclave

The present study aims to investigate the difference of the operation process and the significant mechanical properties between expert workers and beginner workers clearly. The influence of the performance of the carbon fiber reinforced plastic (CFRP) molds made by subjects with difference skill level was discussed. Subjects were allowed to choose their process and molding tools. Subject A had 13 years,and subject B had 1 year of professional experience.The time spent usage of tools and process was recorded by a video camera used for analysis and comparison. Mechanical properties assessed in this study include tensile,compressive and Izod impact properties. The working time analysis shows that subject A needs short time for each process. On the other hand,subject B takes twice time to work for each process compared with subject A. From the surface and cross-section observation, it was found that the molding made by subject B had wrinkles all over and the disorderly inter-layer direction; on the contrary,the wrinkles on the molding surface of subject A are barely,and the inter-layer direction of which are more orderly. The results of tensile and Izod impact tests show that the surface winkles have little influence on the mechanical properties of the molding. According to the compression test and failure structure analysis in edge corner part,it was found that it had a great influence on the compression mechanical properties of the sample belonging to different subjects with different experience.