Weld Lines. 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. 8. As the injection process continues, the two separated melt fronts meet again along the longitudinal section of the plate forming a weld line. Figure 1a illustrates how the weld line is produced when two melt streams merge during the final filling process. Weld line injection molding troubleshooting. Weld-line is a weak area which reduces the strength of the part locally. 2. These flow. Three terms that often get mixed up in injection molding are weld, meld and knit lines. 1. A weld line develops when two or more flow fronts come together but do not meld completely because of partial solidification. Its appearance can be improved by adjusting parameters. In manufacturing, the Weld line or Knit line or Meld line is the line where two flow fronts meet when there is the inability of two or more flow fronts to "knit" together, or "weld", during the molding process. th INTRODUCTION Injection molding is one of the mostWeld lines have been one of the common defects puzzling the injection molding industry. In. This occurs wherever there is a hole, notch, or any other feature on a part which divides the flow of plastic into 2 separate “flow fronts. Ozcelik studied the influence of the injection parameters and weld line on the mechanical properties of polypropylene (PP) during IM process via the design of experiment (DOE). J. Facebook. 7 of the reference. Increase the injection speed. With Ixef® PARA compounds, the strength of a weld line is typically 90 MPa (13,000 psi). 025 100 120 140 160 180 200 220 240 Mold Temperature (F) LDPE PPAbstract. Weld Lines. These flow fronts occur when the molten plastic material encounters obstacles, such as inserts, ribs, or other features within the mold cavity. As the name implies, it is usually positioned along the edge of the workpiece, forming a visible mark at the demarcating line. ชิ้นงานเกิดเป็นเส้นรอยประสาน Weld line. Insufficient plasticizing ability of injection molding machine. The resulting defects don’t stop at flash only. According to the weld line distribution map of six gate schemes shown in . This consequently produces weld lines. Xie L. Meld Lines. Sink Marks Cause 3: Improper Pack or Hold Pressure. One solution is to prevent the weld lines from forming in regions that are. The thermo-rheological findings were used to investigate the sources of weld line weakness. Clamping Unit. This leads to a better molecular chain entanglement, which in turn creates a better weld. 2012. Table 2-Glass Fiber Glass Fiber Glass Fiber Glass Fiber 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. Slow down injection speed. This study focuses on the analysis of fill time by optimizing the injection molding parameters to reduce the defects that are always found on the plastics part such as poor weld line and part not. Weld lines are visually undesirable and a plastic part is structurally weak at weld line positions. The impact behavior of weld-lines in injection molding. Flow lines arise when at least two melt fronts meet at an acute an-Weld line is aesthetically unpleasant and affects the mechanical strength of injection molded parts. Materials Science. Numerical results show that weld lines can be predicted accurately, and the formation and evolution processes of weld line can be shown more clearly by co-injection molding technique. Weld Lines. Meld and knit lines are actually both different types of weld lines. 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-reinforced thermoplastics are still rather few. Increase the injection speed to reduce the amount of cooling happening in the mold. During injection moulding, a weld-line occurs when two or more flow fronts collide in the hollow cavity. ing weld line properties of injection molded thermo-. 2. A knit line in a plastic injection-molded part is created when two separate plastic flows meet within the mold and "resolidify" along their interface. The weld lines that occur in injection mouldings are critical areas on which depends on the strength of the mouldings. This study presents an innovative approach to enhancing weld line strength in advanced polymer injection molding through applying gas-assisted mold. Injection speed is too low. 2017-01-0481. Double push filling method. In this study, epoxy molding compounds (EMC) filled with glass beads were fabricated with a twin-screw-extruder (TSE) and tempered before further processing to generate different degrees of cross-linking (0–15%) in the compounds. Equipment. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. 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. <1> As illustrated in Figure 4, the existence of. To respond to poor plasticization and uneven melt temperature, the molding cycle can be extended to make. The results showed that the tensile strength of PE remains unchanged in the presence of weld lines. Weld lines are one of the typical quality issues of injection molded parts. It is important to investigate the weld line because the weld line area can. Weld Line Factors for Thermoplastics. A weld line can appear during the absence of enough pressure to push the plastic flow and then meld. Remedies: Raise the temperature of the mold or molten plastic. A weld line can also be called a knit line. We have various types and models available. Again, consult with professionals as to how you could improve mold designs. Just check out some of it on the above lists. Insufficient plasticizing ability of injection molding machine. Weld line usually is not allowed on some critical area, and weld line on the part also weaken the strength. Five injection molding process parameters, including mold temperature, melt temperature, packing pressure, injection. Kagitci YC, Tarakcioglu N (2015) The effect of weld line on tensile strength in a polymer composite part. This gives a clue as to. Weld lines. As a result this weld line will be a weak point in this part. This paper presents the. Adjust the position of the gate and include a venting slot. Which means engineers need to know how to account for this phenomenon in an efficient way. Emerging Materials Research. 1, right). Three terms that often get mixed up are weld, meld, and knit lines. Weld lines can impact the strength and appearance of the final part, and are often considered a defect. The impact behavior of weld-lines in injection molding. 000 0. Insufficient plasticizing ability of injection molding machine. In this experiment, several ejector. poor flow fronts that are too cold, this can also lead to a deterioration in the mechanical properties. As these flow fronts come together on the. Weld lines represent the region where two separated melt fronts recombine. 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. 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. 3. The line where two resin flows “knit” or “weld” together during injection molding is called a weld or knit line. Weld or knit lines result wherever two or more polymer flow fronts unite. The. 5. Simulation of polymer molding filling process with an adaptive weld line capturing algorithm. In recent years new methods for quality prediction and optimization of the injection molding process have been proposed and applied. This paper presents the. Int J Adv Manuf Technol:1–11In addition to the weld line, the exposure of fibers on the molded product surface results in a rough surface, which degrades the appearance of the product. [8,9] It is capable of. 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. These lines can weaken the strength of the part, and they can also be unsightly. Conventional injection molding is widely used to produce plastic parts, mainly in the automotive industry, due to the high production ratios and quality of. , Ltd. This customary mark is caused by differential rates of cooling in the resin where. (2011) and Fig. when two or more melt flow fronts contact each other immediately after the cooling process. Plast. 298 µm and the weld line on the heated region was almost eliminated with the aid of induction heating. 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-reinforced thermoplastics are. Designers can easily set up and perform analysis with only a few clicks. 3. Short Shot Short Shot adalah suatu kondisi dimana, plastik leleh yang akan diinjeksikan kedalam cavity tidak mencapai kapasitas yang ideal atau sesuai settingan mesin. 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. Munich, Germany: Carl Hanser Verlag, 1994. อุณหภูมิของพลาสติกเหลวสูงเกินไปจนก๊าซหรือความชื้นแยกตัวออกมาได้. Weld line, 5. In this regard, Taguchi orthogonal experimental design is adopted, and five processing parameters, the mold temperature, melt temperature, cooling time, packing. Wang. 010 0. 3. In the heating step, the heatingOverview of the injection molding process. Bin-Xin Yang Ouyang Jie Supei Zheng Qiang Li Wen Zhou. Article Google Scholar Deng YM, Zheng D, Lu XJ (2008) Injection moulding optimization of multi-class design variables using a PSO algorithm. Weld lines appear as a result of the flow of molten plastic during the injection molding process. Wu CY, Ku CC, Pai HY (2011) Injection molding optimization with weld line design constraint using distributed multi-population genetic algorithm. Recently, injection molding process has generated growing interest, exhibiting great potential to easily fabricate unique polymeric materials for industrial applications. Thereby creating localized pressure within the mold. 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. Miron MC, Major Z, Adachi T. Weld lines form where two or more flow fronts come together and can create a cosmetic or structural problem. 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. In the sense that the weld line is better formed before the resin temperature. This weld line can act as a weak spot in the material. The result is part defects such as weld lines, poor finish, or discoloration. 3 Materials Polypropylene (PP) and. Install an ultrared light inside the hopper. This paper presents the. Ideally, the resin flow will split into two flow fronts to pass around the obstruction and then recombine into a single flow front. Article Google Scholar Xie L, Ziegmann G (2009) Influence of processing parameters on micro injection molded weld line mechanical properties of polypropylene (PP). Berikut beberapa di antaranya: 1. Plastic part design for injection molding – An introduction. Weld-line strength for plastics can vary from 20% to nearly 100% of the strength of the plastic itself. Strength measurements should be made to. Weld lines can compromise the strength and aesthetics of the part, so it’s important to carefully design the mold and. Thus, it is important to understand (i). ResourcesTo study the weld line formation of colliding flow fronts the filling of a mold cavity was simulated. These are caused by the shot of molten plastic moving at different speeds throughout the injection. Weld line. When two or more strands of molten plastics meet in the mold, a weld line will be produced at the junction [1,2]. 4. Adjust the design for the flow pattern to be a single source flow. 1007/s00397-003-0339-2 ORIGINAL CONTRIBUTIONCauses and Remedies of Sink Marks In Injection Molding. Vibration assisted injection molding. These weld lines occur usually around holes or at the material flow joint area in the injeciton molded part, some welding lins is very small, specially if. สาเหตุรองของการเกิดปัญหาการเกิดประกายเงิน (silver streak) 1. In this paper, a kind of polypropylene (PP) foam plastic parts with special weld lines were obtained by core-back foam injection molding with chemical blowing agent. Weld lines in injection molding are frequently unavoidable. The weld line’s strength is reduced when. 5. วัตถุดิบ พลาสติก PMPA ( อะคริลิก ) เกรด A. The edge gate is the most popular and straightforward injection mold gate design. 10 in Nguyen-Chung et al. The parting line in injection molding is which one of the following: (a) the lines formed where polymer melt meets after flowing around a core in the mold, (b) the narrow gate sections where the parts are separated from the runner, (c) where the clamping unit is joined to the injection unit in the molding machine, or (d) where the two mold halves come. A weld line is a mark left on the surface of a plastic injected molded part. [ 18 - 21 ] In addition, the effects. as warpage, shrinkage and weld line of the plastic parts. 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. As the unfavorable defect in micro injection molding parts, weld line brings reduced mechanical and physical properties, especially for nano filled composites. This will produce parts with aExperimental results show that the weld-line strength from a standard test is not applicable in microinjection molding. Injection molding is a complex multi-variable, nonlinear and time-varying unsteady process, which makes it more difficult to optimize the process parameters. The graph shows clearly how an increasing cavity temperature correlates with a reduction in the weld lines. Machine Shot Capacity – The maximum volume of resin that can be injected in a single stroke of the injection machine. 666 Azieatul Azrin Dzulkipli and M. Part design features may cause a material flow to split and rejoin as it flows around design features in a mold. Strength at weld the line location and warpage problem in injection molding plastic component were not new problems in injection molding industries. Powder injection molding comprises several processing steps, and defects may occur in each step if care is not taken. Figure 2. An evaluation model based on artificial neural network method. If the different flow fronts have cooled. In this mold, a visualization design and a rapid heating/cooling system were integrated, and specimens with different cross section. It is a zone with reduced mechanical properties negatively influencing on the molding behavior in exploitation. When this fails to happen correctly, a weld line defect occurs. For this purpose, the width of the weld line calculated by Sigmasoft is. This study addresses the effects of injection molding weld line on the fatigue crack resistance of commercial CPVC in the temperature range of −10 to 70 °C. Wu CY, Ku CC, Pai HY (2011) Injection molding optimization with weld line design constraint using distributed multi-population genetic algorithm. Weld-line is a weak area which reduces the strength of the part locally. [ 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. Weld line formation in the injection molding process occurs. 015 0. 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]. For multiple gate and complex part, molding weld-lines are unavoidable, therefore mechanical behavior of the weld-line needs to be predicted. So today we are going to take a look at the five most common defects in injection molding and their solutions. This gives a clue as to how it was formed. Unless you are manufacturing an extremely simple part with one gate and a unidirectional flow front, your part will have weld lines. The schematic diagram of a weld line formation is illustrated in Figure 7, where is the welding angle of two melt fronts. Let’s review what causes meld and knit line imperfections, how they’re different, and how they affect part durability. 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. In this paper, two different injection molding tests were completed. 9. This reduced thickness of the frozen skin further enhances the visual appeal of the. Weld lines are a common issue in injection molding, and occur when two flow fronts meet and fuse together as the material cools and solidifies. Remember, by avoiding weld lines, you can lessen operations cost. The possibility of the functional thin film for. The following are the reasons. Sink marks are a common type of injection molding defect. Weld lines are injection molding defects that can be mitigated by a number of tactics that depend on your part design. Maintain a holding pressure that is no more than 1/2 the. 2. It occurs when melting plastic material is injected into a mold, it flows through all parts of th. Weld lines in injection molding are frequently unavoidable. The injection molding process can be optimized to maximize weld line strength by increasing. There are several possible causes that need to be investigated to troubleshoot weld lines in injection molding. Co-injection molding technique is a useful way to study weld lines, which can offer more detailed information of the. 18/06/2021. 1. In this case the two flow fronts will meet and there will be very little molecular orientation across the weld. 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. (3-1) Increasing the Resin Temperature at the Weld Line Section. A knit line, also called a weld line, occurs when the liquid plastic moves through the mold and hits more melted plastic and they don’t flow or fuse together. Many works deal with weld lines and their dependence on processing parameters for conventional injection molding, but only a few works focus on the weld line in µIM. A weld line is often unavoidable. Below is one of the examples: !NOTE: if the weld lines is important to the cosmetic surface of your part, please bring this up to your mold maker during quoting phase. Injection molding could be applied with many polymer materials, such as. In this blog post, we will explore the causes of weld lines in. 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. 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. Microsyst Technol, 14 (6) (2008), pp. Yes, it does help, for two reasons: Often the weld line traps air and the ‘dump’ acts as a vent to allow the air to escape. The Influence of Knit-lines on the Tensile Properties of Injection Molded Parts, Polymer Engineering and Science, 23(10): 591-596. Email him at jhenz@polymer-center. Fatigue crack growth (FCG) tests were conducted on SEN specimens prepared from 100 mm. In the plastic injection molding industry, we work with materials that are byproducts of oil refinement and molds made of metal casting, so our terminology is bound to be at least slightly confusing. That helps. And how to use the 3 modes of the sequential controller correctly to prevent burn marks, weld line, short shot, and other part defects in injection molding. S. Effects of mold temperature and pressure on shrinkage 0. Minimize the use of release agent. Investigate for potential contamination. Which means engineers need to know how to account for this phenomenon in an efficient way. 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-reinforced thermoplastics are. Controlling the mold’s temperature could also minimize the weld line’s effects. 1. – Use generous and even. Bubbles are caused by melting flow fronts colliding in a mold cavity. CrossRef View in Scopus Google Scholar [17] G. 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. 1. Gava and co-workers implemented an investigation devoted to the de-weld lines in injection molded thermoplastic composites. The formation of weld lines and their location along the flow path is a well-studied phenomenon in conventional injection molding; however, only a few papers are devoted to micro-injection molding [11,13,14,15,16]. However, even with advanced technologies and precise control, the process is not without its challenges. They decrease the. Stagnant weld lines are formed when melt streams meet head-on. 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. Usually it’s a straight line, and often to be found radiating away from a hole, inclusion or other such part feature. One common issue that frequently arises during injection molding is the formation of weld lines. As compared to a weld line, the flow fronts come together at less than 135 degrees. This may require higher melt temperature or lower injection speed . Optimization of Injection Molding Process to Minimize Weld-line and Sink. Here are some reasons why design is important for injection molding. 2. If the plasticizing ability of the plastics injection molding machine is insufficient, the plastic cannot be fully plasticized, resulting in weld lines when filling the mold. org or visit 80-ton Victor injection molding machine, equipped with an accumulator capable of delivering maximum flow rate of 138 cm 3 /s and providing maximum injection pressure of 210 MPa, is utilized for experiments. These lines can occur at the gate location, where the plastic enters the mold, or anywhere along the flow path. Edge Gates. Joe Henz is a chemical engineer with 30 years of experience in the plastics industry, primarily with GE. This results in a region of a different level of molecular entanglements than the bulk material. 3 and 53. The molded plastic part may also appear to be rust-colored. % glass fibers – PA6 Aramid SV 30-1ETM (figure 1b). Weld Lines-3 Ways for Detecting and Correcting. molding Æ Thermoplastics Æ Weld line Æ Simulation Rheol Acta (2004) 43: 240–245 DOI 10. 3 cc/sec, the weld lines are no longer perceivable above 130 C. Effect of process parameters on the relative weld line strength From injection molding practice and literature, 1, 3,4 it is generally accepted that: if a weld line forms before the filling is. 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. By the reflection method and a high speed camera, the visual system can be used to record and observe the forming process of micro weld lines during the. Rapid heat and cool injection molding is an example of a measure to prevent the generation of weld lines. Injection pressures too high Reduce pressure . The weld lines in injection moulded parts arise as a result of the collision of two fronts of the flowing material, which fills the mould cavity and are sometimes unavoidable. Polym Eng Sci 45(7. 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. Molding with weld line model Moldex3D was used for calculate the molding of lugs (figure 1). The weld lines in blow molding occur wherever the pari son knits together in the head, mold tacking areas and mold parting pinch-off region. 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. A weld line region is typically filled at the end of an injection stroke or during the pressure phase. A weld line is often unavoidable. box, along the region of weld line formation (wc, wm, we and wl) and away from the weld line, in a radial position along the flow direction (R), as shown in Figure 2. Weld or knit lines are perhaps the most common and difficult injection molding defect to eliminate. Flow Lines. Nozzle – The nozzle is at the end of the barrel and contacts the injection mold. [23, 24]. Here are some strategies. Siemens PLM Software. 13 shows the best gate location for which the weld lines . (+86) 760 2222 2556 enquiry@starrapid. + Move gate (to where it is not visible). 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. This study focuses on the effect of melt temperature on. Mechanical properties of the weld line defect in micro injection molding for various nano filled polypropylene composites. 3. 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. Controlling injection molding weld lines with good design and process control. Consequently, weld regions have been observed to have inferior mechanical properties compared to the bulk. Weld line strength is important in blow molding as well as injection molding. According to the characteristics. Injection molding. Weld lines are the result of fundamental physical effects taking place inside of the mold tool cavity, they are common imperfection to be found in most plastic injection molded parts. The optimal process condition is very likely to appear in this second part's fine-tune group. To study the weld line formation of colliding flow fronts the filling of a mold cavity was simulated. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. Our injection molding company is explaining what these imperfections are, why they can compromise. If the injection molding speed is too slow, however, there may be an insufficient filling of the mold. In the 1947 book, Injection Molding of Plastics, the late Dr. (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. Weld lines can be caused by material flowing around holes or inserts in the part, multiple injection gates or variable wall thickness where hesitation or "race tracking" can occur. If the plasticizing ability of the plastics injection molding machine is insufficient, the plastic. It can be determined by a visible line appearing on the surface of the plastic part where two flows of the plastic meet. The wheel has to be gated at three places on the hub and. . Fracture behavior of weld lines in injection molded components loaded under real operating conditions. 5. 1 Prediction of weld lines with injection molding simulation softwareWeld lines in design for manufacture. Venting at Weld Lines. J. Remedies: Raise the temperature of the mold or molten plastic. Moldflow is computer software that is widely used across the plastic injection molding industry to predict and optimize the injection molding process and assist with mold design. These lines usually occur around holes or obstructions and cause locally weak areas in the molded part. Wolfgang Homes, head of the applications department of Eurotool, a manufacturer of hot runner systems, clarified the two methods for IMI, noting that. In the end, the total amount of time that running a complete Taguchi DOE (L18) to occupy an injection. Weld-line is a weak area. Additionally, you can get our free Design Cube, which will provide a physical aid to help understand how knit lines form as well as other injection molding design considerations. 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. Weld lines not only affect the appearance and quality of products, but also cause negative influences on the mechanical properties. Here we are looking at most common part defect that can come from injection molding called weld line. A knit line may be unnoticeable or may look like a crack. Here is a look at the differences between them, the causes of meld and knit line imperfections, and their impact on part durability. Neat polypropylene retains nearly 90% of its strength on a properly designed and molded weld line. 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. Tekanan. Silver Streak. Weld and meld lines are generally caused by holes or inserts in the part, multiple gates, variable wall thickness or hesitation and. Injection Molding Glossary; Weld Lines; Weld Lines. Injection molding plate for mode I testing geometry. 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. High-density PE was also moulded in the same conditions but in a lower temperature range (145 to 220°C). In some cases, a weld line can also cause a loss of strength and impact resistance. As a result this. of micro injection molding process simulation by technology update and progress. To resolve this issue, rapid heat cycle molding (RHCM) has attracted attention as an innovative PIM technology. As the plastic flows through the mold it. 2023年1月3日 / by admin. Weld-line is a weak area which reduces the strength of the part locally. In this lesson we will focus on the meld and weld lines. when two or more melt flow fronts contact each other immediately after the cooling process. This study examines the impact of injection parameters on the weld line strength of the polyamide 6 and 30% fiberglass (PA6 + 30% FG) composite samples. The weld lines are an integral part of plastic injection molding and can seldom be prevented, even by specifically planning the mold with inserts for holes or the like. [1-2] investigated the weld line zone of injection molded glass-fiber-filled polypropylene (PP) composites. Change the gate locations. In addition a weld line can be moved to an area where it is less visible. Keywords: Flow behavior , Injection molding , Particle tracking , Visualization , Weld-line Article MetricsSimulations and experiments were conducted with gas temperatures of 200–400 °C to investigate the impact of external gas-assisted mold temperature control (Ex-GMTC) on the quality of weld line of molding products.