Change the gate locations. The default weld line result recognizes 135º as the maximum angle of collision and as that angle decreases, the severity increases as it. The. Weld Lines are formed when two or more molten polymer flows meet during the injection molding process. g. It is possible to pre. Weld lines can significantly reduce ultimate tensile strength (UTS) and fracture strain of talc filled polypropylene (PP). • Move injection locations to make flow fronts meet more obliquely, turning the weld line into a meld line. If weld lines are unavoidable due to multiple gates in a moulding, they should be positioned in the non-critical region. Insufficient plasticizing ability of injection molding machine. In injection molding weld lines are formed whenever two flow fronts are joined. T he decreased gloss level at the position of. The Factors that Cause Weld Line in Injection molding Pressure. Slow down injection speed. Voids and bubbles, 6. In the case of PC, the model predicts satisfactorily the weld-line strength as a function of injection temperature. Injection molding can be performed with only one of these materials like glass, plastics, etc. The problem with ‘weld lines. 025 100 120 140 160 180 200 220 240 Mold Temperature (F) LDPE PPEffects of mold temperature and pressure on shrinkage 0. The three parameters affecting operation were called injection pressure, injection time, and packing pressure which influence the quality of weld line. Weld lines form where two or more flow fronts come together and can create a cosmetic or structural problem. Molding with weld line model Moldex3D was used for calculate the molding of lugs (figure 1). Thoroughly clean molding machine cylinders. Islyn Thomas summarized the need for a particular vent location better than I ever could. are very minimum. open access Abstract Micro weld lines are the common problem that occurs for plastic molded parts through injection molding process. Procedia Mater Sci 2014; 3: 2048–2053. The type of resin used during injection molding plays a large role in whether or not a knit line will be present. C. Wu CY, Ku CC, Pai HY (2011) Injection molding optimization with weld line design constraint using distributed multi-population genetic algorithm. From Understanding Weld-line Integrity by Sabic Innovative Plastics, p. Let’s review what causes meld and knit line imperfections, how they’re different, and how they affect part durability. This paper presents the. 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. This consequently produces weld lines. poor flow fronts that are too cold, this can also lead to a deterioration in the mechanical properties. Azuddin / Procedia Engineering 184 ( 2017 ) 663 – 672 Fig. The line where two resin flows “knit” or “weld” together during injection molding is called a weld or knit line. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. Technol. Weld lines are significant defects that affect injection molding quality, causing the poor appearance and low mechanical strength of injection‐molded parts. Weld line usually is not allowed on some critical area, and weld line on the part also weaken the strength. In the first, sequential injection moulding, the lines are displaced to noncritical areas of the moulding. This remains as a challenge for control engineers. [1] Kobayashi et al. Controlling the mold’s temperature could also minimize the weld line’s effects. 015 0. 8. Expand. 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. 000 0. when two or more melt flow fronts contact each other immediately after the cooling process. 2012. Figure 2. Injection molding is a complex multi-variable, nonlinear and time-varying unsteady process, which makes it more difficult to optimize the process parameters. 5. Weld lines have been one of the common defects puzzling the injection molding industry. In some cases, a weld line can also cause a loss of strength and impact resistance. During injection moulding, a weld-line occurs when two or more flow fronts collide in the hollow cavity. Fracture behavior of weld lines in injection molded components loaded under real operating conditions. Recently hired at plastic injection molding simulation software provider Moldex3D, Nicholson was spurred to undertake the research study following a conversation with a customer experiencing weld-line woes. 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. 2. 226-233. Weld lines can appear on the components when the molten plastics meet each other as they are flowing from two different parts of the mold. on conventional reciprocating screw injection molding machines using molding practices standard for filled engineering thermoplastics . In this case the two flow fronts will meet and there will be very little molecular orientation across the weld. These are caused by the shot of molten plastic moving at different speeds throughout the injection. These flow. Known methods to reduce weld-line effects are the optimization of injection molding parameters, enhanced tool temperature, and using special molding tool devices. Learn more about ABS injection molding here. Meddad and Fisa [3] found that the weld line is a zone between 2 and 8 mm wide extending throughout the thickness in which the fibers are oriented almost. Weld lines in injection molding are formed when two or more flow fronts of molten plastic material meet and merge during the molding process. In this case the two flow fronts will meet and there will be very little molecular orientation across the weld. The thermo. Flashes, 3. Improper fusion of two fluid flows, a state before weld line. Weld or Knit lines are a plane or section in an injection molding part where the flow of molten plastics meets from different directions. Weld lines often generate mechanically weak areas, because of the unfavorable perpendicular orientation of the macromolecules, fibers and/or other fillers to the direction of the main flow. Therefore, the length of flowing weld lines must be additionally defined. The following guidelines have. Article Google Scholar Xie L, Ziegmann G (2009) Influence of processing parameters on micro injection molded weld line mechanical properties of polypropylene (PP). Weld lines, knit lines, and meld lines are terminologies to describe the imperfections of finished parts in plastic injection molding processing. Insufficient injection pressure and speed can cause 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. Steven. ResourcesTo study the weld line formation of colliding flow fronts the filling of a mold cavity was simulated. 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. Minimize the use of release agent. , a post that forms a hole) and then rejoins, or when polymer melt fronts meet, from multiple injection points. Reposition gates and runners to allow resin to flow around the obstruction from a. Plastic part design for injection molding – An introduction. Wu CH, Liang WJ (2005) Effects of geometry and injection-molding parameters on weld-line strength. An injection molding gate is a critical component in mold design, acting as the passage through which molten plastic travels from the runners into the mold cavity. They. Weld lines. Adding vents, using overflows, or using porous metal. 7 in Kobayashi et al. Tekanan. NX Mold Flow Analysis. Polyamide 6 (Lanxess, Durethan B 30 S 000000, non-reinforced, ISO 1874-PA 6, GR, 14-030, Cologne, Germany) was used for this experiment. The gate vestige for injection molding is usually narrow. Poor weld line Ⅰ. In this regard, the plasticizing ability of the plastic injection moulding machine should be checked. Nozzle – The nozzle is at the end of the barrel and contacts the injection mold. Weld lines are injection molding defects that can be mitigated by a number of tactics that depend on your part design. They are unavoidable even for moderate complex products. Knit lines in injection molding are undesirable, especially when surface appearance and part strength are significant concerns. 18 ชิ้นงานเกิดเป็นเส้นรอยประสาน Weld line. This model provides the necessary information. Injection molding weld lines refer to a line on an injection molded part that is generated where the two halves of the mold come together. Flow lines are off-color lines, streaks, and other patterns that appear on the surface of a part. Figure 2. Weld lines form where two or more flow fronts come together and can create a cosmetic or structural problem. Usually it’s a straight line, and often to be found radiating away from a hole, inclusion or other such part feature. These lines can occur at the gate location, where the plastic enters the mold, or anywhere along the flow path. Raising the mold temperature will keep the material molten longer, resulting in stronger weld lines and even elimination of weld lines. 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. 2004; To study the weld line formation of colliding flow fronts the filling of a mold cavity was simulated. The weld line’s strength is reduced when. Therefore, the investigation on the developing process of weld line would be a significant issue for improving the quality of micro injection molded parts. Weld lines are also known as knit lines. Wolfgang Homes, head of the applications department of Eurotool, a manufacturer of hot runner systems, clarified the two methods for IMI, noting that. Weld line is formed when two different melt flows converge, as illustrated in Fig. An evaluation model based on artificial neural network method. Melt temperature is 250°C, mold temperature is 110°C. The effects of these two injection molding process parameters are explained in terms of their influence on the skin-core morphology observed on the fracture surfaces in the weld zone. There are several possible causes that need to be investigated to troubleshoot weld lines in injection molding. ชิ้นงานเกิดเป็นเส้นรอยประสาน Weld line. . This leads to a better molecular chain entanglement, which in turn creates a better weld. Ideally, the resin flow will split into two flow fronts to pass around the obstruction and then recombine into a single flow front. A good weld typically occurs when the melt temperature where the weld line is formed is no more than 20°C below the injection temperature. It is important to investigate the weld line because the weld line area can induce potential failure of structural application. Unless you are manufacturing an extremely simple part with one gate and a unidirectional flow front, your part will have weld lines. Its design significantly impacts the final product’s appearance, strength, and functionality, making it crucial for manufacturers to understand its intricacies and variations thoroughly. Investigate for potential contamination. 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. When two or more streams of plastic meet and fuse. Here are some reasons why design is important for injection molding. A weld line (weld point, flow line or a knit line) forms when separate melt fronts travelling in opposite directions meet. 3. To resolve this issue, rapid heat cycle molding (RHCM) has attracted attention as an innovative PIM technology. When two or more streams of plastic meet and fuse together, a visible line or weakness is formed on the surface of the finished product. Weld Line defect analysis, the most common of many defects in injection moulding products. A simulation process was conducted to determine the recommended setting of injection moulding parameters and the range of the variable. The weld line is an inevitable defect in the most injection molded components. In this lesson we will focus on the meld and weld lines. Weld lines form where two or more flow fronts come together and can create a cosmetic or structural problem. The possibility of the functional thin film for. This study focuses on the effect of melt temperature on. The injection molding simulation software used offers a method for the detection of weld lines that has shown to be only reliable for the detection of stagnating weld lines. Three terms that often get mixed up are weld, meld, and knit lines. Investigate for potential contamination. 1. 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. Visualization analysis of flow behavior during weld-line formation in injection molding process. A meld line occurs when two moving melt fronts converge and flow parallel to each other. 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. J. Weld line reduction is one of the major concerns in plastic injection molding (PIM) that results in high surface appearance and high strength of a plastic product. 030 0. 5 mm, 1. <Materials> Pre-dry thoroughly. A weld line is a mark left on the surface of a plastic injected molded part. Various measures are taken at production sites to address these problems. Install an ultrared light inside the hopper. 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 are a common imperfection to be found in most plastic injected molded parts. This failure causes the product to be damaged during use. Simulation of polymer molding filling process with an adaptive weld line capturing algorithm. 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. Weld line additionally called as knit line, is a defect that occurs when the injected plastic meets within a. The gate is the critical bridge between the runners (the channels through which the molten plastic travels) and the actual mold. A quantitative evaluation of the appearance quality of weld lines in RHCM parts. They decrease the. In the heating step, the heatingOverview of the injection molding process. Sink Marks Cause 3: Improper Pack or Hold Pressure. 6. and Mosle, H. 6. 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]. 2020-01-1306. We investigate the effects of various heating times and. Flow-induced filler orientation and weld lines are un-avoidable facets of the injection molding process. In this blog post, we will explore the causes of weld lines in. 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. technical ulletin SPECIALTY POLYME RS Design and Production of Injection Molding Tools. These flow fronts occur when the molten plastic material encounters obstacles, such as inserts, ribs, or other features within the mold cavity. The appearance quality of plastic parts in weld lines can be improved significantly through the rapid heating cycle molding (RHCM). 3 cc/sec, the weld lines are no longer perceivable above 130 C. The weld line length was selected as part of the quality index to investigate the effects of gate location on weld. Increase the injection speed. Again, consult with professionals as to how you could improve mold designs. Weld-line is a weak area which reduces the strength of the part locally. The flow of the material in the injection mould takes place through the gate. Gate position in injection mold. Polymers 2023, 15, 2440 3 of 21. replication and poor weld line strength . 2002), the use of simulation approaches (Berti and. In an injection molding process, a weld-line forms when two flow fronts meet each other. Xie L. DescriptionThis insertion ensures the separation of the melt flow. Email him at jhenz@polymer-center. Effects of fillers and/or reinforcements on weld-line strength of nylon 6/6. Polym Eng Sci 45(7. 015 0. Furthermore, injection molding was applied by filling these pellets into a micro-injection molding machine (C. 2. Plastic part design for injection molding – An introduction. Therefore, it is recommended to do a moldflow study prior to the mold being built. In recent years new methods for quality prediction and optimization of the injection molding process have been proposed and applied. Abstract. สาเหตุรองของการเกิดปัญหาการเกิดประกายเงิน (silver streak) 1. To explore the formation of. 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. [23, 24]. In an injection molding process, a weld-line forms when two flow fronts meet each other. Flow marks in injection molding can be avoided if adequate measures are taken. Weld Line Phenomenon: Surface defect in which the weld, or the part where the flows of melted plastic meet inside the mold, shows up on the surface as a groove or pattern. Which means engineers need to know how to account for this phenomenon in an efficient way. 005 0. 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. 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 optimum injection molding parameters to manufacture the product was determined by . There are several possible causes that need to be investigated to troubleshoot weld lines in injection molding. That helps. The following are the conclusion drawn from the present research: 1. Five injection molding process parameters, including mold temperature, melt temperature, packing pressure, injection. 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. 1. Again, consult with professionals as to how you could improve mold designs. Examples of such failure are shown in Figure 1. . 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. As a result this weld line will be a weak point in this part. Miron MC, Major Z, Adachi T. Known also as knit lines 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. 22 shows how the weld lines are formed when the melt splits around core pins during the injection molding process. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. Here we are looking at most common part defect that can come from injection molding called weld line. of micro injection molding process simulation by technology update and progress. [ 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. Known methods to reduce weld-line effects are the optimization of injection molding parameters, enhanced tool temperature, and using special molding tool devices. 2021年4月23日 / by admin. What causes them? The primary cause is weak bondage between two or more flow fronts. For multiple gate and complex part, molding weld-lines are unavoidable, therefore mechanical behavior of the weld-line needs to be predicted. Weld line problem which occurs in polymer parts produced by plastic injection method and affects appearance and strength on a large scale was researched in this paper. Weld lines. A tensile test specimen mold, which allows cavity thickness varying from 2. Micro-injection molding (µIM) is a widespread process for the production of plastic parts with at least one dimension, or feature, in the microscale (conventionally below 500 µm). Vertical Plastic Injection Molding Machine [10, 11, 12] 2. Re-balancing entire manufacturing lines may be required to effectively deliver and sustain SMED excellence. A poor knit line can cause only cosmetic blemishes or it can significantly weaken the structural integrity of a part. Penyebab Weld Line. Injection molding is nothing without molds. Controlling injection molding weld lines with good design and process control. Weld lines represent the region where two separated melt fronts recombine. <1> As illustrated in Figure 4, the existence of. Abstract. Because of the ever-increasing requirements for parts performance, lots of researchers have perf. The gate location should enable the two flow fronts to merge easily and continue to flow beyond the weld line. The position, length, and angle of weld lines are dependent on the. (1998) for clear photographs. These lines can occur due to variations in wall thickness, gate location, or the geometry of the part. 2011; 509 (2):226–233. 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. 10(a) (please see Fig. Sink marks are a common type of injection molding defect. JENIS-JENIS DEFECT (CACAT) PADA PRODUK INJECTION MOLDING PT. Why You Should Avoid Weld Lines. Investigations on WLs in micro injection molded parts were performed in Refs. 030 0. Weld lines are formed when there is an inability of two or more flow fronts to ‘knit’ or ‘weld,’ together during the molding process. When two or more strands of molten plastics meet in the mold, a weld line will be produced at the junction [1,2]. 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 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. 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. The Solutions for Poor Welding Lines. Fracture behavior of weld lines in injection molded components loaded under real operating conditions. Weld lines may appear like seams or scratches, but that is not what they are. The weld lines that occur in injection mouldings are critical areas on which depends on the strength of the mouldings. 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. As such, optimizing mold designs should always be incorporated in your production model. Information about PA6/PA66 (Nylon) Injection Molding. Weld lines occur when melt flow fronts meet during the injection molding of plastic parts. They occur when melt flow fronts collide in a mold cavity. Which means engineers need to know how to account for this phenomenon in an efficient way. Weld Lines and Fibers There are two basic types of weld lines: the stagnant and the flowing [1]. Injection molded plastic parts have comparatively less strength in the weld line section and they also have an impact on product aesthetics. The design of the mold, as well as the part being molded, has a significant impact on the success of the process. 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. 3. + Move gate (to where it is not visible). Mold vents should function the same way. une, 13: 15. 3. In order to prepare the weld line specimen by micro injection molding, a mould integrated with visual system and variotherm system was designed and constructed, shown as Fig. , Ltd. Let’s review what causes meld and knit line imperfections, how they’re different, and how they affect part durability. Although this phenomenon occurs in almost all the commercially important polymer. Make the size of runner channel wider and/or shorter. 2007; Lotti et al. 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. Polym. In our DFM report, we will analyze the possible weld lines. % glass fibers – PA6 Aramid SV 30-1ETM (figure 1b). อุณหภูมิของพลาสติกเหลวสูงเกินไปจนก๊าซหรือความชื้นแยกตัวออกมาได้. When this fails to happen correctly, a weld line defect occurs. 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. So today we are going to take a look at the five most common defects in injection molding and their solutions. This month, in our FREE SimTech™ series of webinars, we will explore weld lines and how they develop. A micro-photography study on the cross-section of the weld-line was also carried out. For thick-walled parts, slow injection rates result in more uniform polymer distribution . A weld line is a mark left on the surface of a plastic injected molded part. 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. Insufficient plasticizing ability of injection molding machine. In the injection molding process, weld line regions occur when a molten polymer flow front is first separated and then rejoined. Weld line existence reduces the material strength; however, its. Remedies: Raise the temperature of the mold or molten plastic. Weld lines Weld lines are weak areas formed by converging flows of plastic that can lead to mechanical part failure if not properly accounted for in the part design. 3. Figure 1a illustrates how the weld line is produced when two melt streams merge during the final filling process. Weld-line strength for plastics can vary from 20% to nearly 100% of the strength of the plastic itself. Injection Molding Glossary; Weld Lines; Weld Lines. In. The occurrence of a weld line means a significant problem both aesthetically and mechanically in the design of injection moulded parts. They happen when two flow fronts of melted plastic meet and solidify, leaving a visible line on the surface of the part. 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. ”Weld Lines in a plastic cover. Wang, G. Known also as knit lines and weld marks, weld lines are difficult to eliminate completely, especially if your injection molded part requires holes. First, an injection mold with triangular inserts was built to study the influence of meeting angles on material properties at the weld line. Figure 1 below shows the development of a weld line. Its properties make it possible to create thin-walled parts having close tolerances in fast cycles over long. Weld lines are a common occurrence in injection molding that affects the overall quality and strength of a finished product. The result is part defects such as weld lines, poor finish, or discoloration. 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. Weld line formation in the injection molding process occurs when two or more melt flow fronts contact each other immediately after the cooling process. This method was adopted. 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. ). Here is a look at the differences between them, the causes of meld and knit line imperfections, and their impact on part durability. This paper evaluates the shrinkage and strength of weld line using Design of Experiment and Response Surface Methodology in multi-objective optimisation utilising the injection moulding parameters. However, even with advanced technologies and precise control, the process is not without its challenges. After that, the compounds were injection-molded into tensile samples with and without weld lines to. Sink Marks Cause 1: Incorrect Melt Temperature. 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. Injection molding of large/complicated products are usually prepared by multiple compounds, which produces weldlines once the melt fronts are joined by impingement flow. <Materials> Pre-dry thoroughly. Increase the mold temperature. Molding Equipment. However, research about the computer determination of weld lines in injection molding remains scarce. Meld and knit lines are actually both different types of weld lines. Weld lines represent the region where two separated melt fronts recombine. This will produce parts with aExperimental results show that the weld-line strength from a standard test is not applicable in microinjection molding. Thus, it is important to understand (i). Computer simulation packages of injection molding have had success in predicting filling behavior in extremely complicated geometries, capable of predicting weld lines’ location exactly. 2-1. 4. (3) Adjust the temperature of the barrel and nozzle: the viscosity. When two or more strands of molten plastics meet in the mold, a weld line will be produced at the junction [1,2]. The following are the reasons. As the unfavorable defect in micro injection molding parts, weld line brings reduced mechanical and physical properties, especially for nano filled composites. 3 and 53. This results in a region of a different level of molecular entanglements than the bulk material. Weld lines are visually undesirable and a plastic part is structurally weak at weld line positions. Equipment. Edge Gates. 010 0. To determine the effect of the weld lines on tensile strength, tensile tests were conducted with the specimens fabricated with NORYL (amorphous blends of. Polym Eng Sci 45(7):1021–1030. In addition a weld line can be moved to an area where it is less visible. , 509 (2) (2011), pp. These are preferred over weld lines as they will normally result in improved cosmetics and structure. Knit lines, weld lines, mold lines, or flow lines in injection molding are faint lines that become visible on certain plastic parts. Weld lines in injection molding are frequently unavoidable. Short Shot Short Shot adalah suatu kondisi dimana, plastik leleh yang akan diinjeksikan kedalam cavity tidak mencapai kapasitas yang ideal atau sesuai settingan mesin. 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. As the name implies, it is usually positioned along the edge of the workpiece, forming a visible mark at the demarcating line. Injection speed is too low. 943 µm to 0. 1 Prediction of weld lines with injection molding simulation softwareWeld lines in design for manufacture. (3-1) Increasing the Resin Temperature at the Weld Line Section. Remedies: Raise the temperature of the mold or molten plastic. A weld or meld line is a weakness or visible flaw created when two or more flow paths meet during the filling process. Injection molding plate for mode I testing geometry. Problem: Weld lines are formed when plastic resin is forced around an obstruction in a mold tool and reforms on the side opposite the gate. Poor weld line quality can lead to short-term or long-term product failures, initiated at the weld line. 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. สาเหตุการเกิด weld line คือเมื่อการไหลของพลาสติกมาประสานกันนะจุดใดจุดหนึ่งและจุดนั้นเกิดความแตกต่างของอุณหภูมิในสองทิศทางการไหลจะทำให้เกิด. A weld line can appear during the absence of enough pressure to push the plastic flow and then meld. Facebook. 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. 1. M. 2.