sheet molding compound是什么意思

英语翻译
Injection molding machines are manufactured in many sizes.These are rated according to size by the amount of material which can be injected in one cycle,which ranges from a fraction of an ounce in the small laboratory models to many pounds in large production equipment .Laboratory models are used in the research and development of new polymers and molding techniques.
There are two basic units to an injection molding machine; one for injecting the heated plastic and one for opening and closing the mold.The first unit includes a feed hopper,heated injection cylinder ,and an injection plunger or screw system.The second unit comprises a hydraulic operated moving platen and a stationary platen on which the halves of the mold are mounted.Injection molding machines are also available in vertical models.
There are many variations in injection molding machine design,however,the basic machines are of either the screw-ram,or plunger type.The main difference between these types is the method in which the plastic material is delivered from the hopper to the nozzle of the machine.Machines of the reciprocating-screw type are used more because of the material.
The injection molding machine has a variety of instrumentation used for the clamping unit,mold,and injection molding machine.Fig.2.1.1 shows the most important possibilities of the instrumentation.In fact ,there is no known direct method for in-line checking of the condition of the mold.
A typical laboratory injection molding machine,will vary in shot capacity from a few grams to about one-half ounce.It will have a clamping device that is usually hand operated with a cam action and an injection system operated manually or by compressed air.The injection system exerts very high pressure on the mold,from 5000 to 20000 psi.It is therefore necessary for the mold to be clamped together with a greater pressure than the injection pressure or the mold halves will be forced apart and flash(squeeze out of resin at the parting line of the mold)will result.
The loading chute and the heating cylinder make up the other major components of the machine.Most of the laboratory size machines are of the plunger type.
Injection molding is especially suitable for high production runs,most machines produce several thousand products an hour.Virtually all thermoplastic resins can be injection molded,however,some are more difficult to process and require specialized equipment.From a knowledge of polymer structure,it becomes evident that resins with wide melting range mold easier than those with a sharp or narrow melting point,Other factors to consider are the molding temperature requirements,moisture absorption of the resin,and the necessary properties required for the product.For example,acetal resin has a sharp melting point,turning quickly to a liquid,which requires exacting temperature controls.

英语翻译
Use of Resin Transfer Molding
Simulation to Predict Flow,
Saturation,and Compaction in the
VARTM Process
N.C.Correia
F.Robitaille
A.C.Long
C.D.Rudd
School of Mechanical,Materials,
Manufacturing Engineering and Management,
University of Nottingham,U.K.
P.S ˇ
ima ´c ˇek
S.G.Advani*
Department of Mechanical Engineering,
Center for Composite Materials,
University of Delaware,USA

英语翻译
Problem:Poor Finish
When molding Renprene TPVs and our other TPE products,pressures in the
mold work to increase the contact between the shot material and the mold surface.Generally,high injection pressures maintain part properties,improve part appear- ance and reduce molding cycle times.When the melt flow pressures do not allow for the material to pack out evenly against the mold cavity,poor surface finish
can result.
Mold Fill Is Too Slow
The majority of our TPVs are shear dependent.They require fast mold filling via high injection speeds and pressure to increase shear through the system,which reduces their viscosity.If increasing injection pressure and injection speed does not rem-
edy a poor finish,increasing the melt temperature and mold temperature will also improve surface appearance when molding our materials.
Mold Function Is Incorrect
First make sure that venting and gate size are not reducing the melt flow speed.Vents that are too small can lead to trapped air in the mold cavity,which can slow melt flow into the cavity.We do not recommend using mold releases or lubricants.Over time,the lubricants may actually cause the parts to stick in the mold due to build up and vent clogging.Be sure that the mold surface is clean.Avoid thick ribs and bosses that will create sink marks on the opposite side of the part.
Problem:Poor Surface Detail
The leading causes of surface detail problems on parts molded from Santoprene TPVs are improper filling and packing conditions.Pressures in the mold work to increase the contact between the shot material and the mold surface.Generally,high injection pressures maintain part properties,improve part appearance,and reduce molding cycle times.A reduction of pressure in the mold cavity can be caused by the gate freezing off prematurely,poor mold design,or low pack/
hold pressures.Verify that the set up conditions are correct using the Start Up
Procedures.
Mold Filling Improperly
If material is not filling surface details on the part,there may not be enough pres- sure or material to fill the part.First check that the shot size is correct.If the shot size is correct,try increasing the injection speed and back pressure.This will help ensure there is enough pressure in the mold to encourage contact between the melt flow and the mold surface.
Packing Conditions Are Improper
Under-packing of the mold cavity can lead to excessive shrinkage,shrink voids in thicker wall sections,sinks in large surface areas,and poor part appearance.Traditionally,mold fill time takes between 0.5 and 2 seconds,depending on
part volume,runner-gate style and size,cavity locations,and injection pressure.Increasing the second stage pressure and time will also help to maintain pressures in the mold necessary for good surface finish.
Polymer Cooling Rate Is Too High
Increasing mold temperatures will help by reducing the cooling rate of the melt and encouraging filling of surface details.

英语翻译
In the injection molding process of regular parts the heat
flow from the polymer melt to the mold wall during the
filling stage can be neglected due to the short filling times.
However,the local heat flow has a high impact on the
polymer flow in the surface structures during the filling
stage and is considered by a one dimensional heat conduction
model.The freezing of the polymer melt in surface
structures depends significantly on the temperature level
chosen on the mold wall and the glass-transition temperature
of the amorphous molding material used.
Therefore,in order to mold surface structures with
higher qualities a higher mold wall temperature is necessary
which results in increased cooling time.In contrast,
parts with a lower surface quality allows for a reduction in
mold wall temperature.Due to the higher temperature
gradients occurring in the filling and cooling stages the
cooling time is then reduced significantly.

英语翻译
Genesis and Vantage Series
Transfer Molding Presses 与其类似的一种压力机

blow molding with accumulators什么意思
还有compounding/masterbaches Producer什么意思

英语翻译
With regards to injection molding life cycle inventories
(LCI),much effort has gone into studying the production of
raw materials (polymers) as well as the product end-of-life
aspects,such as disassembly separation and recycling.
Amongst the researchers in this area,it is worth mentioning Ian
Boustead,who developed a set of “eco-profiles,” or LCI’s,of
the most consumed polymers in the plastic industry.He also
created life cycle inventories for injection molded PVC and
injection molded polypropylene.The former LCI studied two
injection molding facilities in France that produce PVC fittings
for pipe drainage systems [2].The latter LCI studied one
facility in the U.K.that produces 12 to 76 g polypropylene
components [3].These studies are product specific,narrowing
on one application and one set of processing parameters.In an
effort to obtain a range of values typical in injection molding,
and thus more breadth of data,this study incorporates
measurements from machines processing different products
and materials.It also provides a transparent outline of all the
sub-processes that make up the injection molding process
together with their environmental performance.
Other contributors to the field of injection molding include
Mattis et al.1996 and Boothroyd et al.2002.Mattis et al.used
a 3-D solid modeling environment and numerical analysis to
explore the influence of mold design,part design,and some
process parameters on the process efficiency [4].Boothroyd et
al.,whose goals were to develop design-for-manufacturing
guidelines,developed a set of empirical equations predicting
machine size and processing time of each stage in the injection
molding cycle [5].
翻译的好追50分

英语翻译
Blow molding is the third largest plastics processing technique worldwide and is generally recognized to be one of the fastest growing areas in the plastics industry[1].One of the essential steps which constitutes the blow molding cycle is the inflation of the parison.The entire process of parison inflation occurs in two successive stages,namely,free inflation followed by confined inflation.The parison inflation process is highly complex,involving the interaction of several process variables,such as the inflation pressure,material characteristics,parison thickness distribution,and parison temperature profile.
There have been quite a few reports in the existing literaturre on the simulation of parison inflation[2--9].Ryan and Dutta[3] made an analytical treatment of the free inflation of a viscoelastic parison by assuming a one-dimensional isothermal deformation.This simplified analyses cannot be used to predict realistic shapes of the parison during its inflation.
The finite element method (FEM) has been used to simulate the inflation of parison over the last decade[4--9].However,modeling blow molding inflation process with the FEM requires that many of the most difficult aspects of the FEM be addtessed in the analysis.These difficulties arise because of large strains,large deformations,nonlinear material behavior and so on during the inflation of parison.
In this paper,a mathematical model has been derived for simulating the parison free inflation in the plastics extrusion blow molding.In order to evaluate the predictive capabilities of the model,the instantaneous images of parison inflation within a mold epuipped with glass side windowa have been obtained by using a video capture technique.
1 Theoretical Analysis
Consider the free inflation of an isotropic and incompressible annular parison with an uniform radius and thickness,and length 2L in the initial state,as shown in Fig.1.The parison is assumed to be treated as a membrane (with thickness much less than any radius of curvature) so that any change in the deformation variables across the thickness may be neglected.Gravity and surface tension effects are neglected.Cylindrical polar coordinate system(r,r,x) is taken and all puantities are independent of r because of symmetry.Amaterial particle that locates at (r,r,x) during inflation is originally at (r,r,x).The ends of the parison are at x=0 and x=2L,and there is symmetry about the plane x=L.

英语翻译
Thermoplastic Injection Molding:New Packages and 3D Circuits
Abstract
Thermoset epoxies,discovered nearly 80 years ago,remain the workhorse materials for electronic packaging and printed
circuit boards,but this may change with increasing technical,economic and regulatory demands.Modern halogen-free
thermoplastics boast superior properties and automated high-efficiency high-volume processes.Injection molding can readily
produce intricate 3D structures suitable for packaging and 3D molded circuits.Although there is a well-established packaging
infrastructure geared to thermoset epoxies there is a much larger world-wide manufacturing base that excels in thermoplastics.
Nearly 16-billion pounds of thermoplastics are molded into parts each year in the USA alone; 30 times higher than for
epoxies.The time may be right for adding thermoplastic packages,interconnects and circuitry to 21st century electronics.
This paper will discuss concepts,novel designs,new processes and the advancements for injection molded packaging and
highlight their impressive attributes; the lowest moisture uptake,the fastest processing and the highest stability in the world
of polymers.While MEMS packaging will be a central theme,general component packaging will also be discussed including
power packages and camera modules.The discussion will include the development of new BGA concepts that utilize
automatic insert-molding of tiny metal balls to create the 1st and 2nd level interconnect system.Assembly topics will cover
package sealing methods that include laser welding.
New Multi-Chip Package (MCP) ideas based on insert-molded flex will be described that could find use in stackable designs.
Hermeticity is discussed using data to show that plastics are near-hermetic but do not yet pass MIL-STD levels.But,future
work with barrier coatings may eventually lead to a low cost full hermetic plastic package.And finally we’ll look at 3D
molded circuits,now called MID (Molded Interconnect Devices),and search for new applications.Conductor patterning
methods include molding with plating-catalyzed resin and direct laser writing.We will also consider the idea of combining
molded circuitry and packaging for maximum synergy.
请在5月30号以前译出!可要求加分50~100分 ,能者多劳,

什么是 foam in bag molding system
请问一下foam in bag molding system 是什么东西,原文是这样的,use foam in bag molding system to obtain molded pieces.mold part from 0.4 density sprayed foam in place.请帮忙全部翻译一下就更好了,