Weld line injection molding. The weld lines in injection molded parts arise as a result of the collision of two fronts of the flowing material, which fills the mold cavity and are sometimes unavoidable [1][2][3] [4]. Weld line injection molding

 
 The weld lines in injection molded parts arise as a result of the collision of two fronts of the flowing material, which fills the mold cavity and are sometimes unavoidable [1][2][3] [4]Weld line injection molding injection molding, (b) weld line and meld line, and (c) injection sample size and shape

In this paper, aiming at the problem of weld line defects in the injec- tion process of a key phone panel, the injection process is optimized by using Moldflow and drop simulation. Weld lines in injection molding occur when two flow fronts meet and create a visible line on the surface of the molded part. Bociaga and Jaruga (2007) investigated flowing weld line in injection process by injection molding machine, which the part surface was observed in reflected light using the optimal microscope and. In. In this paper, two different injection molding tests were completed. Meld Lines. Weld lines form where two or more flow fronts come together and can create a cosmetic or structural problem. The molded plastic part may also appear to be rust-colored. As a result this weld line will be a weak point in this part. The welding angle can be used to differentiate weld lines and meld lines. This is expected to achieve maximum results while the pressure holding effect will also increase. Procedia Mater Sci 2014; 3: 2048–2053. After that, the compounds were injection-molded into tensile samples with and without weld lines to. The weld line in injection molding is created when two melt streams connect, as shown in Figure 1. Since weldline in plastic injection molding (PIM) has an influence on not only the strength but also the surface appearance of a plastic product, it is preferable to reduce it as much as possible for high product quality. A visible weld line is observed, due to a combina-The Weld line result itself has a scale associated with the placement of the weld line that is directly relative to how severe the weld line will be based on the angle in which the two flow fronts meet. In this study the polycarbonate (PC) and carbon fiber (CF) are used as the experimental materials to investigate the impact of injection molding process parameters on tensile strength of weld line. Melt temperature is 250°C, mold temperature is 110°C. Gate position in injection mold. 6. Gate Placement: Properly positioning the gate can direct the melt flow to minimize weld lines or relocate the weld line to non-visible areas of the part. Thoroughly clean molding machine cylinders. Failure may result due to the assembly torque, or end-use application loads (temperature, creep). This thermal field was transferred to an injection molding flow solver to compare simulations and experimental results from the high speed video, both with and without the effect of induction heating. a) Multi-fiber connector micro injection molding simulation b) 3D simulation of micro gear with 150µm diameter for weld line position prediction c) 3D micro injection molding filling simulation of micro gear with 180µm diameter Fig. It occupies a major part in the plastics industry ranking second to plastic extrusion in terms of production and the utilization of both thermoplastic and thermosetting plastic materials. Weld line existence reduces the material strength; however, its demerit characteristics. To explore the formation of weld lines in injection molding, a. 3. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. This method was adopted. One common issue that frequently arises during injection molding is the formation of weld lines. A weld line occurs when two or more molten plastic flows meet and fuse during the injection molding process, resulting in a visible line on the surface of the molded part. Adjust the design for the flow pattern to be a single source flow. 4If the injection gate is not properly designed, it can cause the formation of defects like sink-mark, warpage, short shot, weld-line, air traps, and other faults [15]. Insufficient plasticizing ability of injection molding machine. Fig. This customary mark is caused by differential rates of cooling in the resin where. [ 18 - 21 ] In addition, the effects of flow behavior of the polymer melt due to the optimal process parameters for the minimization of weld-line effects are an important consideration. A weld line is a visible seam where two areas of the molten plastic meet. Known methods to reduce weld-line effects are the optimization of injection molding parameters, enhanced tool temperature, and using special molding tool devices. Unless you are manufacturing an extremely simple part with one gate and a unidirectional flow front, your part will have weld lines. Co-injection molding technique is a useful way to study weld lines, which can offer more detailed information of the. . The weld line in injection molding is created when two melt streams connect, as shown in Figure 1. It is not always easy to completely eliminate weld lines by simply adjusting the relevant injection mold design or the molding conditions. In this lesson we will focus on the meld and weld lines. Flow Lines. A knit line may be unnoticeable or may look like a crack. Weld lines, knit lines, and meld lines are terminologies to describe the imperfections of finished parts in plastic injection. Munich, Germany: Carl Hanser Verlag, 1994. In a weld line, reinforcement fibers adopt an orthogonal orientation with respect to the filling direction, which results in a significant reduction in the strength and. Investigations on WLs in micro injection molded parts were performed in Refs. 3. Vibration assisted injection molding. Figure 1a illustrates how the weld line is produced when two melt streams merge during the final filling process. Weld line strength is influenced by the temperature at which the weld line is formed and the pressure exerted on the weld until the part freezes, (pressure is 0 at the weld line). This paper presents the. The cracking was always located in the weld/knit line and therefore caused by weakness in the bonding of the plastic at. Gambar 2. molding Æ Thermoplastics Æ Weld line Æ Simulation Rheol Acta (2004) 43: 240–245 DOI 10. • Move injection locations to make flow fronts meet more obliquely, turning the weld line into a meld line. Islyn Thomas summarized the need for a particular vent location better than I ever could. A weld line is often unavoidable. of micro injection molding process simulation by technology update and progress. These lines can occur at the gate location, where the plastic enters the mold, or anywhere along the flow path. A poor knit line. This occurs mainly in the presence of barriers that divide the melt flow in. Some of the common fixes for weld lines include: Increase the resin temperature to ensure both sides of the weld line are liquid when colliding. For the production of these weld‐line specimens, a special mold was used and injection molding parameters were systematically varied, tensile (ISO 527‐2) and impact (ISO 179‐1/1eU. Munich, Germany: Carl Hanser Verlag, 1994. Wu CH, Liang WJ (2005) Effects of geometry and injection-molding parameters on weld-line strength. Weld Lines. Ideally, the resin flow will split into two flow fronts to pass around the obstruction and then recombine into a single flow front. Fiber content dependence on. One of the things that can compromise an injection molded part is a weld line, also called a knit line. In the present study, Moldflow&#xae; software is applied to simulate the injection molding of automobile instrument light guide bracket and optimize the injection gate position. The thermo-rheological findings were used to investigate the sources of weld line weakness. Weld lines are significant defects that affect injection molding quality, causing the poor appearance and low mechanical strength of injection‐molded parts. * Corresponding author, e-mail: fengsjpc@ku. The results showed that the tensile strength of PE remains unchanged in the presence of weld lines. Some of the approaches include the application of machine learning methods (Chen 2008; Manjunath and Krishna 2012; Kuo et al. Weld lines form where two or more flow fronts come together and can create a cosmetic or structural problem. During injection. Mechanical properties of the weld line defect in micro injection molding for various nano filled polypropylene composites. In injection molding of thermosoftening plastics, an important aspect having a bearing on the quality of articles is the appearance of weld lines that are formed when there are inserts, barriers, molding signs, reinforcements, etc. Zhao, X. As the name implies, it is usually positioned along the edge of the workpiece, forming a visible mark at the demarcating line. Computer simulation packages of injection molding have had success in predicting filling behavior in extremely complicated geometries, capable of predicting weld lines’ location exactly. Change the gate locations. 3 cc/sec, the weld lines decrease over temperatures up to 150 C, while at higher volumetric injection flow rates of 43. This consequently produces weld lines. The formation of weld line in the injection molding method is caused by the product and mold design that is one of the common mistakes. Unfortunately, the 3D layering process creates ‘weld lines’ (an injection molding term) between layers which is essentially two layers of polymer that meet. Crack growth behavior. To determine the effect of the weld lines on tensile strength, tensile tests were conducted with the specimens fabricated with NORYL (amorphous blends of. Lugs size is 65 х 24 х 4 mm. In recent years new methods for quality prediction and optimization of the injection molding process have been proposed and applied. Processing OptimizationReduced frozen skin thickness: High injection speeds also contribute to a thinner frozen skin at the weld line. (2) Causes & Countermeasures (See the table below) *Note: Flash also tends to occur when the injection pressure/speed are too high, but molding time is too long and mold temperature is too low. From Understanding Weld-line Integrity by Sabic Innovative Plastics, p. C. Which means engineers need to know how to account for this phenomenon in an efficient way. 1. These are preferred over weld lines as they will normally result in improved cosmetics and structure. Here is a look at the differences between them, the causes of meld and knit line imperfections, and their impact on part durability. Silver Streak. Meld and knit lines are actually both different types of weld lines. 1007/s00397-003-0339-2 ORIGINAL CONTRIBUTIONCauses and Remedies of Sink Marks In Injection Molding. They are the result of fundamental physical effects taking place inside of the mold tool cavity. Xie L, Zhu D, Ziegmann G, Steuernagel L (2016) Investigation on correlation between cold/hot weld line mechanical properties and micro injection molding processing parameters. They. Weld lines not only affect the appearance and quality of products, but also cause negative influences on the mechanical properties. Insufficient plasticizing ability of injection molding machine. Compd. Remedies: Reduce packing and fill rates by adjusting until the part is properly filled with minimum stresses. Ejector System (Pötsch, 1995) . Weld-line strength for plastics can vary from 20% to nearly 100% of the strength of the plastic itself. Weld Lines are formed when two or more molten polymer flows meet during the injection molding process. Reposition gates and runners to allow resin to flow around the obstruction from a. G. First, an injection mold with triangular inserts was built to study the influence of meeting angles on material properties at the weld line. The. Weld lines appear as a result of the flow of molten plastic during the injection molding process. gas, which can cause blistering, as well as poor weld lines, warpage and the formation of cold slugs that affect filling and part mechanical properties. The graph shows clearly how an increasing cavity temperature correlates with a reduction in the weld lines. Bin-Xin Yang Ouyang Jie Supei Zheng Qiang Li Wen Zhou. With Ixef® PARA compounds, the strength of a weld line is typically 90 MPa (13,000 psi). Penyebab Weld Line. 030 0. ResourcesTo study the weld line formation of colliding flow fronts the filling of a mold cavity was simulated. 2. Injection moulding (U. Weld Line defect analysis, the most common of many defects in injection moulding products. 2. Gate Placement: Properly positioning the gate can direct the melt flow to minimize weld lines or relocate the weld line to non-visible areas of the part. Siemens PLM Software. Despite injection molding being recognized as a robust process for obtaining parts with high geometry accuracy, one last occurrence remains a challenge in micro-injection molding, especially when junctions are. Weld lines represent the region where two separated melt fronts recombine. Weld lines are visually undesirable and a plastic part is structurally weak at weld line positions. Increase the injection speed. The weld line length was selected as part of the quality index to investigate the effects of gate location on weld. Jiquan Li, Taidong Li, +1 author. 010 0. Weld lines are one of the typical quality issues of injection molded parts. Sink Marks Cause 4: High Mold Temperature. Weld lines in injection molding are a type of cosmetic defect that detracts from a plastic part’s appearance. For thick-walled parts, slow injection rates result in more uniform polymer distribution . Polym Eng Sci 45(7. In the injection molding process, weld line regions occur when a molten polymer flow front is first separated and then rejoined. Flow front tracing simulation results for weld line developing process in micro injection molding with Comsol ® Multiphysics 3. Weld lines in injection molding are formed when two or more flow fronts of molten plastic material meet and merge during the molding process. What Causes Weld Lines in Plastic Injection Molding Parts? I. Weld lines are formed when two orAbout Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright. This study presents an innovative approach to enhancing weld line strength in advanced polymer injection molding through applying gas-assisted mold. It is a zone with reduced mechanical properties negatively influencing on the molding behavior in exploitation. The injection molding process can be optimized to maximize weld line strength by increasing. In the first, sequential injection moulding, the lines are displaced to noncritical areas of the moulding. Except for a few very simple injection molded parts, they occur on most injection molded parts (typically in the form of a line or V-groove), especially large complex items that require use of multi-gate molds and inserts. Gava and co-workers implemented an investigation devoted to the de-weld lines in injection molded thermoplastic composites. But the unfavorable and unavoidable defect of weld line in micro injection molding part leads to detrimental mechanical and surface properties. 3. Injection pressure or. Five industry pros with more than 200 years of combined molding experience provide step-by-step best practices on mounting a mold in a horizontal injection molding machine. If so, look for an alternative resin. Weld lines are also known as knit lines. These master batches and PP pellets were dry-blended by adjusting the ratio such that the fiber contents were 10, 20, and 30 wt%. Weld lines occur when melt flow fronts meet during the injection molding of plastic parts. To resolve this issue, rapid heat cycle molding (RHCM) has attracted attention as an innovative PIM technology. (1)Injection Machine Poor plasticization and non-uniform melt temperature – appropriately extend the injection molding cycle, to ensure thorough plasticization, and change for a machine with a larger. It provides scientific basis for designers toWeld lines are significant defects that affect injection molding quality, causing the poor appearance and low mechanical strength of injection‐molded parts. In. This reduced thickness of the frozen skin further enhances the visual appeal of the. In the 1947 book, Injection Molding of Plastics, the late Dr. Wavy lines are another feature of weld lines. Meld lines are formed when two separate flow fronts meets. Here are some strategies. สาเหตุรองของการเกิดปัญหาการเกิดประกายเงิน (silver streak) 1. (1983). Mobile 0813; Shinko Sellbic Co. Polymers 2023, 15, 2440 3 of 21. Google Scholar | Crossref | ISI. Injection molding. Our weld line injection molding is essential for the best result of finished molded products. Thus, a right gate design raises polymer temperature to prevent the formation of weld lines and flow marks. th INTRODUCTION Injection molding is one of the mostWeld lines have been one of the common defects puzzling the injection molding industry. In this work, the weldline strength of injection molded short-glass-fiber reinforced polycarbonate was derived by an analytical method of modified rule-of-mixtures as a function of the area fraction between skin and core layers. Miron MC, Major Z, Adachi T. One of the factors that determines the quality of injection molded parts is the weld line [50,75,76]. The default weld line result recognizes 135º as the maximum angle of collision and as that angle decreases, the severity increases as it. Weld lines can impact the strength and appearance of the final part, and are often considered a defect. Burn Marks. Knit lines, weld lines, mold lines, or flow lines in injection molding are faint lines that become visible on certain plastic parts. 1 Prediction of weld lines with injection molding simulation softwareWeld lines in design for manufacture. ac. Weld lines are a common occurrence in injection molding that affects the overall quality and strength of a finished product. 020 0. Designers can easily set up and perform analysis with only a few clicks. That helps. Lesson 6: Meld and Weld Lines (Processing) When plastic flows into an injection mold, the internal flow pattern depends on the part design, mold design, and processing factors. Nguyen-Chung. weld lines in infill analysis of injection molding simulation was observed [5]. warpage, and weld line. Weld lines not only detract from an injection-molded part’s surface quality, but also significantly reduce its mechanical strength. 2) Vents in an injection mold should let the air out, but not the liquid plastic. Fracture behavior of weld lines in injection molded components loaded under real operating conditions. Weld line additionally called as knit line, is a defect that occurs when the injected plastic meets within a. It has larger cross-sectional regions that allow sufficient molten plastic flow into the cavity. Many researchers had emerged with several. To respond to poor plasticization and uneven melt temperature, the molding cycle can be extended to make. [ 18 - 21 ] In addition, the effects of flow behavior of the polymer melt due to the optimal process parameters for the minimization of weld-line effects are an important consideration. 2 mm to 1. Three terms that often get mixed up in the plastic injection molding industry are weld, meld, and knit lines. To prevent knit lines, injection molders can increase the temperature of the molten resin to prevent solidification from starting too soon, and increasing injection speeds and pressure are also potential solutions. This remains as a challenge for control engineers. The flow disruptor is a small insert introduced inside the injection molding cavity, in the weld line area, and its objective is to mix the melt and disrupt fountain flow in order to blur and. Weld line and warping are two critical defects for injection-moulded part. Depending on the resin, resin temperature, mold temperature, and filling speed, knit lines can vary. Optimization of Injection Molding Process to Minimize Weld-line and Sink. 5. When an external load is applied to a weld line region, the part’s potential for mechanical failure is increased. Weld-line yield strength, yield strain, and failure strain of talc-filled polypropylene increase with increasing melt temperature and increasing hold pressure. In this regard, Taguchi orthogonal experimental design is adopted, and five processing parameters, the mold temperature, melt temperature, cooling time, packing. Increase the melting temperature. This happens when the molten plastic is injected into the mold cavity and flows around an obstacle such as a pin, hole, or protrusion, and then comes back together. In this case the two flow fronts will meet and there will be very little molecular orientation across the weld. A simulation process was conducted to determine the recommended setting of injection moulding parameters and the range of the variable. The second technique, cascade injection moulding, can produce parts free from weld lines. Technol. For the production of these weld‐line specimens, a special mold was used and injection molding parameters were systematically varied, tensile (ISO 527‐2) and impact (ISO 179‐1/1eU. Controlling injection molding weld lines with good design and process control. as warpage, shrinkage and weld line of the plastic parts. Tekanan. The problem with ‘weld lines. The schematic diagram of a weld line formation is illustrated in Figure 7, where is the welding angle of two melt fronts. A weld line refers to a line, notch or color change that is created on the molded part caused by the convergence of two separate flows of molten plastic. The gate location should enable the two flow fronts to merge easily and continue to flow beyond the weld line. This gives a clue as to how it was formed. In this study, the effects of injection temperature, injection pressure, and fiber content on the mechanical properties of weld lines were studied for carbon fiber-reinforced nylon. The defects encountered could be caused by mechanical factors, such as poor mold design and mold manufacturing, or by processing related factors, such as incomplete kneading, inadequate molding pressure, injection. The possibility of the functional thin film for. This study presents an innovative approach to enhancing weld line strength in advanced polymer injection molding through applying gas-assisted mold temperature control, significantly increasing mold temperature beyond typical values observed in conventional processes. The melt stream is separated at the part’s cutout and reunited at the other end of the cutout. <Mold> Increase (or decrease) the size of the runners and gates. injection molded pipe-fittings with and without weld line. A weld line region is typically filled at the end of an injection stroke or during the pressure phase. The weld-lines are undesirable from both aesthetic and functional points of view and their effect is different for varied materials, process conditions, loadings, forms. Figure 1 a illustrates how the weld line is produced when two melt streams merge during the final filling process. Wavy lines are another feature of weld lines. 1. Thus, it is important to understand (i) if the melt is able to fill the cavity up to the weld line location, (ii) where the weld line forms, and (iii) if the weld line is a cold or flowing one. Thus, it is important to understand (i). The weld line is an inevitable defect in the most injection molded components. Fig 13:- Detailed view of weld lines. The following are the conclusion drawn from the present research: 1. Weld Lines. In the sense that the weld line is better formed before the resin temperature. Weld lines can be caused by several different problems: Low temperature of injection moulding machine barrel. Weld lines in injection molding are frequently unavoidable. The impact behavior of weld-lines in injection molding. During injection moulding, a weld-line occurs when two or more flow fronts collide in the hollow cavity. Thus, it is important to understand (i). The. Wang, G. This will produce parts with aExperimental results show that the weld-line strength from a standard test is not applicable in microinjection molding. The injection pressure is too lowEffect of the processing conditions on the variations of the bulk temperature, T b , at the end of mold filling at the two locations: in (left) and away (right) from the weld-line (T w , T inj. As the injection process continues, the two separated melt fronts meet again along the longitudinal section of the plate forming a weld line. Article Google Scholar Deng YM, Zheng D, Lu XJ (2008) Injection moulding optimization of multi-class design variables using a PSO algorithm. 3. This leads to a better molecular chain entanglement, which in turn creates a better weld. C. Install an ultrared light inside the hopper. Weld line. Weld lines. To study the weld line formation of colliding flow fronts the filling of a mold cavity was simulated. • Optimize the design of the runner system. Strength at weld the line location and warpage problem in injection molding plastic component were not new problems in injection molding industries. Learn how to avoid them and what injection molding companies do to prevent them. when two or more melt flow fronts contact each other immediately after the cooling process. Multi-Shot Molding – A molding process that uses two or more plastic materials to form a single part. In the end, the total amount of time that running a complete Taguchi DOE (L18) to occupy an injection. Methodology. According to the weld line distribution map of six gate schemes shown in . A weld line (weld point, flow line or a knit line) forms when separate melt fronts travelling in opposite directions meet. Alloys. Polym. These lines are formed when two or more flowing molten plastic streams meet and fuse together, creating a visible line on the surface of the molded part. These lines can occur due to variations in wall thickness, gate location, or the geometry of the part. Weld lines represent the region where two separated melt fronts recombine. • Reduce runner dimensions and maintain the same flow rate. The definition of weld lines: When multiple plastic flow fronts meet in the cavity after encountering inserts, holes, or areas with inconsistent flow rates or interrupted melt flows, or in the case of gate injection filling, the inability of two or more flow fronts to fully “knit” together will cause the linear weld marks. Meld and knit lines are actually both different types of weld lines. In our DFM report, we will analyze the possible weld lines. The strength of the weld-line area can be increased by optimizing injection molding process parameters like melt temperature, injection speed, packing pressure, changing gate type and location, etc. The Solutions for Poor Welding Lines. The weld-lines are undesirable from both aesthetic and functional points of view and their effect is different for varied materials, process conditions, loadings, forms of weld-line, etc. DYNAPLAST Tbk. Maintain a holding pressure that is no more than 1/2 the. technical ulletin SPECIALTY POLYME RS Design and Production of Injection Molding Tools. A weld line refers to a line, notch or color change that is created on the molded part caused by the convergence of two separate flows of molten plastic. A new kind of weld line was. Weld lines are a common defect generated in injection molding, which apparently affects the performance of final products, but the available reports on carbon fiber. com1. 18/06/2021. With Ixef® PARA compounds, the strength of a weld line is typically 90 MPa (13,000 psi). Introduction. Simulation of polymer molding filling process with an adaptive weld line capturing algorithm. Park et al. Weld line is formed when two different melt flows converge, as illustrated in Fig. [23, 24]. 7 in Kobayashi et al. T. The effects of filling time, packing time, packing pressure, melt temperature, and mold temperature on the ultimate tensile strength (UTS) and the elongation value of the weld. If it only affects the appearance, it can change the position of the burn four to change the position of the weld line. Weld lines can compromise the strength and aesthetics of the part, so it’s important to carefully design the mold and. This is expected to achieve maximum results while the pressure holding effect will also increase. The position, length, and angle of weld lines are dependent on the. Weld lines are among the most critical structural defects in parts made by the injection molding of fiber-reinforced thermoplastics, explained Sirmax in a press release. Increase the injection speed to reduce the amount of cooling happening in the mold. Weld lines are formed when there is an inability of two or more flow fronts to ‘knit’ or ‘weld,’ together during the molding process. Flash. Key words: weld line strength, thermoplastic composites, injection molding, wall thickness, skin and core layers Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand. 809-814. (1998) for clear photographs. poor flow fronts that are too cold, this can also lead to a deterioration in the mechanical properties. The formation of weld line in the injection molding method is caused by the product and mold design that is one of the common mistakes. However, even with advanced technologies and precise control, the process is not without its challenges. Weld lines are a common imperfection to be found in most plastic injected molded parts. Weld lines can lower the integrity of the part. injection molding, (b) weld line and meld line, and (c) injection sample size and shape. In some cases, a weld line can also cause a loss of strength and impact resistance. Injection molding weld lines where two or more flow fronts come together in the mold. The need to minimize fiber breakage, plus the higher viscosity of materials with. The terahertz time-domain spectroscopy (THz-TDS) imaging technique was used to detect the weld line defect of an injection-moulded short glass fiber-reinforced composite. 025 100 120 140 160 180 200 220 240 Mold Temperature (F) LDPE PPAbstract. Its properties make it possible to create thin-walled parts having close tolerances in fast cycles over long. Neat polypropylene retains nearly 90% of its strength on a properly designed and molded weld line. (1) Increase the injection pressure and prolong the injection time. 2012. 5 mm, 1. Avient’s Zachary Alderman shares practical tips on designing and injection molding parts utilizing short-fiber reinforcements. This gives a clue as to. Weld line defects are a common part defect that occurs when the injected plastic flows around a solid piece of the mold and does not knit back together. These lines can weaken the strength of the part, and they can also be unsightly. The weld line’s strength is reduced when. A weld line develops when two or more flow fronts come together but do not meld completely because of partial solidification. + Optimize holding pressure time. (2) Causes & Countermeasures (See the table below) *Note: Flash also tends to occur when the injection pressure/speed are too high, but molding time is too long and mold temperature is too low. Poor weld line Ⅰ. They can affect the strength and appearance of the part, depending on the temperature, pressure, speed, and mold design of the injection molding process. Mold flow analysis can predict the location of weld lines. Mold flow analysis is widely employed in mold making industry, utilizing data simulation software, the injection molding process can be simulated and presented on the computer,. th e use of design of e xperiment techniq ue.