注塑模具畢業(yè)設(shè)計(jì)外文翻譯--立體光照成型的注塑模具工藝的綜合模擬

1、 1附錄2Integrated simulation of the injection molding process with stereolithography moldsAbstract Functional parts are needed for design verification testing, field trials, customer evaluation, and production planning. B

2、y eliminating multiple steps, the creation of the injection mold directly by a rapid prototyping (RP) process holds the best promise of reducing the time and cost needed to mold low-volume quantities of parts. The potent

3、ial of this integration of injection molding with RP has been demonstrated many times. What is missing is the fundamental understanding of how the modifications to the mold material and RP manufacturing process impact bo

4、th the mold design and the injection molding process. In addition, numerical simulation techniques have now become helpful tools of mold designers and process engineers for traditional injection molding. But all current

5、simulation packages for conventional injection molding are no longer applicable to this new type of injection molds, mainly because the property of the mold material changes greatly. In this paper, an integrated approach

6、 to accomplish a numerical simulation of injection molding into rapid-prototyped molds is established and a corresponding simulation system is developed. Comparisons with experimental results are employed for verificatio

7、n, which show that the present scheme is well suited to handle RP fabricated stereolithography (SL) molds. Keywords Injection molding Numerical simulation Rapid prototyping 1 IntroductionIn injection molding, the poly

8、mer melt at high temperature is injected into the mold under high pressure [1]. Thus, the mold material needs to have thermal and mechanical properties capable of withstanding the temperatures and pressures of the moldin

9、g cycle. The focus of many studies has been to create the injection mold directly by a rapid prototyping (RP) process. By eliminating multiple steps, this method of tooling holds the best promise of reducing the time and

10、 cost needed to create low-volume quantities of parts in a production material. The potential of integrating injection molding with RP technologies has been demonstrated many times. The properties of RP molds are very di

11、fferent from those of traditional metal molds. The key differences are the properties of thermal conductivity and elastic modulus (rigidity). For example, the polymers used in RP-fabricated stereolithography (SL) molds h

12、ave a thermal conductivity that is less than one 3used to create physical models for visual inspection and form-fit studies with very limited func-tional applications. However, the newer generation stereolithographic pho

13、topolymers have improved dimensional, mechanical and thermal properties making it possible to use them for actual functional molds. 2 Integrated simulation of the molding process 2.1 Methodology In order to simulate the

14、use of an SL mold in the injection molding process, an iterative method is proposed. Different software modules have been developed and used to accomplish this task. The main assumption is that temperature and load bound

15、ary conditions cause significant distortions in the SL mold. The simulation steps are as follows: 1The part geometry is modeled as a solid model, which is translated to a file readable by the flow analysis package. 2Simu

16、late the mold-filling process of the melt into a photopolymer mold, which will output the resulting temperature and pressure profiles. 3Structural analysis is then performed on the photopolymer mold model using the therm

17、al and load boundary conditions obtained from the previous step, which calculates the distortion that the mold undergo during the injection process. 4If the distortion of the mold converges, move to the next step. Otherw

18、ise, the distorted mold cavity is then modeled (changes in the dimensions of the cavity after distortion), and returns to the second step to simulate the melt injection into the distorted mold. 5The shrinkage and warpage

19、 simulation of the injection molded part is then applied, which calculates the final distortions of the molded part. In above simulation flow, there are three basic simulation modules. 2. 2 Filling simulation of the melt

20、 2.2.1 Mathematical modeling In order to simulate the use of an SL mold in the injection molding process, an iterative method is proposed. Different software modules have been developed and used to accomplish this task.