Facebook. Technol. A meld line occurs when two moving melt fronts converge and flow parallel to each other. Article Google Scholar Deng YM, Zheng D, Lu XJ (2008) Injection moulding optimization of multi-class design variables using a PSO algorithm. 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. Edge Gates. Weld line and warping are two critical defects for injection-moulded part. 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. Int J Adv Manuf Technol 52:131–141. ac. 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. 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. An evaluation model based on artificial neural network method. 2002), the use of simulation approaches (Berti and. warpage, and weld line. Flash. 3 cc/sec, the weld lines are no longer perceivable above 130 C. So today we are going to take a look at the five most common defects in injection molding and their solutions. In this paper, a weld line computer determination method based on filling simulation with surface model is proposed, from which the positions and lengths of the weld lines can be predicted. In this study, we apply the technique of SAW to explore the acoustic properties near injection-weld lines by comparing the velocity of. Since it is often impossible to avoid weld lines as well as a limited possibility to increase the weld line strength by adjusting the injection molding parameters, a method to predict the weld line strength in the product development process is shown below. 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. 4 at different time steps (legend scale is volume fraction of. Visualization analysis of flow behavior during weld-line formation in injection molding process. 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. Part design features may cause a material flow to split and rejoin as it flows around design features in a mold. Weld lines are a common imperfection to be found in most plastic injected molded parts. Improper fusion of two fluid flows, a state before weld line. (1) Increase the injection pressure and prolong the injection time. In spite of the symmetry of the molding the formed weld line was not straight, due to a slight unbalance of the two injection gates. Mold flow analysis can predict the location of weld lines. This can occur when a polymer flow splits to go around an interruption (e. Wolfgang Homes, head of the applications department of Eurotool, a manufacturer of hot runner systems, clarified the two methods for IMI, noting that. Therefore, the investigation on the developing process of weld line would be a significant issue for improving the quality of micro injection molded parts. Short Shot Short Shot adalah suatu kondisi dimana, plastik leleh yang akan diinjeksikan kedalam cavity tidak mencapai kapasitas yang ideal atau sesuai settingan mesin. Weld-line is a weak area which reduces the strength of the part locally. + Adjust injection speed. Plastic part design for injection molding – An introduction. A weld line is a visible seam where two areas of the molten plastic meet. of micro injection molding process simulation by technology update and progress. Known methods to reduce weld-line effects are the optimization of injection molding parameters, enhanced tool temperature, and using special molding tool devices. Weld line section presents notch or gloss difference. (1) Flash: Extra plastic material in the shape of films or burrs, which appears on the parting surface, around the runner or in the insert crevice. Plastics manufactured by injection molding are meant to be durable and reliable, able to hold up to heavy use, high temperatures, or adverse conditions. Weld lines in injection molding are frequently unavoidable. CrossRef View in Scopus Google Scholar [17] G. 809-814. 32–24. (1) Flash: Extra plastic material in the shape of films or burrs, which appears on the parting surface, around the runner or in the insert crevice. 3. Injection Molding Glossary; Weld Lines; Weld Lines. Still, it can be seen to varied degrees depending on mold. * Corresponding author, e-mail: fengsjpc@ku. If so, look for an alternative resin. Fiber content dependence on. J. But none of the current packages can predict weld lines’ properties qualitatively. Wavy lines are another feature of weld lines. Wang. Weld or knit lines result wherever two or more polymer flow fronts unite. Sink Marks Cause 4: High Mold Temperature. 9. Install an ultrared light inside the hopper. Weld lines are visually undesirable and a plastic part is structurally weak at weld line positions. In the case of PC, the model predicts satisfactorily the weld-line strength as a function of injection temperature. These lines can weaken the strength of the part, and they can also be unsightly. Flow marks in injection molding are defects that manifest as a line or series of lines forming a pattern different in color from the other parts of the molded material. Try to gradually raise the mold temperature and barrel temperature. This is a video excerpt from our Problems & Solutions Course - Weldlines. Double push filling method. In this experiment, several ejector. This defect occurs due to the temperature and pressure not being high enough, causing premature solidification. Munich, Germany: Carl Hanser Verlag, 1994. Weld line is formed when two different melt flows converge, as illustrated in Fig. 9 – Over Packing. 005 0. The Influence of Knit-lines on the Tensile Properties of Injection Molded Parts, Polymer Engineering and Science, 23(10): 591-596. Tekanan yang kurang mampu untuk mendorong aliran dan kembali pada posisi semula dapat menimbulkan weld line. 1. The impact behavior of weld-lines in injection molding. Gambar 2. Injection pressures too high Reduce pressure . 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. Miron MC, Major Z, Adachi T. 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. ResourcesTo study the weld line formation of colliding flow fronts the filling of a mold cavity was simulated. Slow down injection speed. ). Interestingly, these materials have been shown to outperform long fiber thermoplastic (LFT) composites (in. He said, “Vent cavities at weld lines or junction points where two or more material streams meet and fuse into a solid mass. Weld lines are formed when there is an inability of two or more flow fronts to ‘knit’ or ‘weld,’ together during the molding process. The weld line refers to the process in which the liquid material is divided into two or more flows in the cavity during the injection process and merged together after a period of time [51,77,78,79]. The weld line is an inevitable defect in the most injection molded components. Weld lines can impact the strength and appearance of the final part, and are often considered a defect. Designers can easily set up and perform analysis with only a few clicks. He now teaches courses in injection molding and plastic part design at the Polymers Center of Excellence and UNC-Charlotte in Charlotte, N. That’s the air escaping out of the nozzle until the hose is full of pressurized water. 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. The main types of injection molding defects are: 1. 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. Consequently, it causes viscous dissipation which leads to the generation of heat. Weld line usually is not allowed on some critical area, and weld line on the part also weaken the strength. Investigate for potential contamination. Weld lines are a common occurrence in injection molding that affects the overall quality and strength of a finished product. 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. 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. Gate blush, 4. Avient’s Zachary Alderman shares practical tips on designing and injection molding parts utilizing short-fiber reinforcements. Kondisi ini juga bisa menandakan bahwa mesin injection. They occur when melt flow fronts collide in a mold cavity. 6. 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. อุณหภูมิของพลาสติกเหลวสูงเกินไปจนก๊าซหรือความชื้นแยกตัวออกมาได้. This model provides the necessary information. Meld and knit lines are actually both different types of weld lines. 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. The three parameters affecting operation were called injection pressure, injection time, and packing pressure which influence the quality of weld line. When molten plastic flows, it forms a smooth continuous flow until it meets an obstruction. Fellahi et al. 1, right). Meld and knit lines are actually both different types of weld lines. 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. Depending on the resin, resin temperature, mold temperature, and filling speed, knit lines can vary. DYNAPLAST Tbk. Kagitci YC, Tarakcioglu N (2015) The effect of weld line on tensile strength in a polymer composite part. Meld and knit lines are actually both different types of weld lines. molding Æ Thermoplastics Æ Weld line Æ Simulation Rheol Acta (2004) 43: 240–245 DOI 10. Email him at jhenz@polymer-center. Just check out some of it on the above lists. Weld lines can compromise the strength and aesthetics of the part, so it’s important to carefully design the mold and. The thermo-rheological findings were used to investigate the sources of weld line weakness. Consultant @ Effinno Technologies, BSME, MBA - Bridge between Plastics Injection Molding Knowledge and Practice. สาเหตุรองของการเกิดปัญหาการเกิดประกายเงิน (silver streak) 1. (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. Remember, by avoiding weld lines, you can lessen operations cost. Injection molding is one of the most established and well-known methods of plastic processing. However, research about the computer determination of weld lines in injection molding remains scarce. Plast. Figure 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. 943 µm to 0. also utilized the co-injection molding technique to study the flow of polypropylene at the weld line behind an obstacle in injection molding; the weld line can be seen clearly from the Fig. Polyamide 6 (Lanxess, Durethan B 30 S 000000, non-reinforced, ISO 1874-PA 6, GR, 14-030, Cologne, Germany) was used for this experiment. A weld line is often unavoidable. Reposition gates and runners to allow resin to flow around the obstruction from a. Flow Lines. 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 injected. 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. , a post that forms a hole) and then rejoins, or when polymer melt fronts meet, from multiple injection points. The weld line in injection molding is created when two melt streams connect, as shown in Figure 1. In an injection molding process, a weld-line forms when two flow fronts meet each other. Weld lines may appear like seams or scratches, but that is not what they are. Boost time too long Shorten boost time, lower boost pressure, or move transfer to an earlier position . In. Its properties make it possible to create thin-walled parts having close tolerances in fast cycles over long. We have various types and models available. 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. Crack growth behavior. The weld line length was selected as part of the quality index to investigate the effects of gate location on weld. The second technique, cascade injection moulding, can produce parts free from weld lines. Three terms that often get mixed up in injection molding are weld, meld and knit lines. As such, optimizing mold designs should always be incorporated in your production model. Usually it’s a straight line, and often to be found radiating away from a hole, inclusion or other such part feature. Adjust Injection Molding Parameters: Optimizing injection speed, pressure, and temperature can help ensure better melt flow and reduce the likelihood of weld line formation. Weld lines appear on the surface of a molded part where the molten material converges after splitting off into two or more directions in a mold. Adjust the design for the flow pattern to be a single source flow. Five injection molding process parameters, including mold temperature, melt temperature, packing pressure, injection. Methodology. 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. , 509 (2) (2011), pp. The possibility of the functional thin film for. <Materials> Pre-dry thoroughly. 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. If the different flow fronts have cooled. 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,. The Solutions for Poor Welding Lines. Polym Eng Sci 45(7):1021–1030. th INTRODUCTION Injection molding is one of the mostWeld lines have been one of the common defects puzzling the injection molding industry. Here are some strategies. 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]. Although this phenomenon occurs in almost all the commercially important polymer. Weld Line Factors for Thermoplastics. This paper presents the. 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, knit lines, and meld lines are terminologies to describe the imperfections of finished parts in plastic injection. Vertical Plastic Injection Molding Machine [10, 11, 12] 2. These lines can occur at the gate location, where the plastic enters the mold, or anywhere along the flow path. A weld line develops when two or more flow fronts come together but do not meld completely because of partial solidification. To increase the sustainability of the process, determinative parameters and their effects should be examined. See moreIncreasing the temperature of the mold or plastic material. This study describes how the weld line was formed on the part. For multiple gate and complex part, molding weld-lines are unavoidable, therefore mechanical behavior of the weld-line needs to be predicted. 005 0. The need to minimize fiber breakage, plus the higher viscosity of materials with. 2. Weld Lines and Fibers There are two basic types of weld lines: the stagnant and the flowing [1]. 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. This reduced thickness of the frozen skin further enhances the visual appeal of the. 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. The following are the reasons. Consequently, weld regions have been observed to have inferior mechanical properties compared to the bulk. 3 Materials Polypropylene (PP) and. 2. อุณหภูมิของพลาสติกเหลวสูงเกินไปจนก๊าซหรือความชื้นแยกตัวออกมาได้. Emerging Materials Research. Weld lines appear as a result of the flow of molten plastic during the injection molding process. The design of the mold, as well as the part being molded, has a significant impact on the success of the process. Alloys. It occurs when melting plastic material is injected into a mold, it flows through all parts of th. According to the characteristics. In this paper, a weld line factor (W-L factor) was adopted to describe the. Xie L, Ziegmann G (2008) A visual mold with variotherm system for weld line studying micro injection molding. If you have critical requirements for strength of knit lines, please call a Protolabs applications engineer at 877-479-3680 to discuss, or email at [email protected]. The. <Mold> Increase (or decrease) the size of the runners and gates. 3. 18/06/2021. In recent years new methods for quality prediction and optimization of the injection molding process have been proposed and applied. Maintain a holding pressure that is no more than 1/2 the. They decrease the. Tekanan. 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. 2. 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. 21: Weld line failure caused by hoop stresses. This remains as a challenge for control engineers. 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]. Ada berbagai penyebab mengapa weld line bisa muncul pada permukaan produk plastik. 5. g. “I realized weld -line problems are a very common issue for injection molded parts,” Nicholson told Plastics Technology. Thoroughly clean molding machine cylinders. With tighter heat controls, you can keep the material at the proper temperature to make sure the plastic keeps flowing and fills the mold cavity completely. This study presents an innovative approach to enhancing weld line strength in advanced polymer injection molding through applying gas-assisted mold. weld lines in infill analysis of injection molding simulation was observed [5]. But the unfavorable and unavoidable defect of weld line in micro injection molding part leads to detrimental mechanical and surface properties. Injection molding is a highly versatile manufacturing process used to produce a wide range of plastic products with precision and efficiency. [1] Kobayashi et al. Weld Line defect analysis, the most common of many defects in injection moulding products. Zhao, X. For thick-walled parts, slow injection rates result in more uniform polymer distribution . Fracture behavior of weld lines in injection molded components loaded under real operating conditions. Micro injection molded polymeric parts coated with functional thin films/layers show off the promising applications in microsystems area. With Ixef® PARA compounds, the strength of a weld line is typically 90 MPa (13,000 psi). This failure causes the product to be damaged during use. 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. Fisa et al. The following are the conclusion drawn from the present research: 1. 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. Description Knit lines, weld lines, mold lines, or flow lines in injection molding are faint lines that become visible on certain plastic parts. J. Let’s review what causes meld and knit line imperfections, how they’re different, and how they affect part durability. The wheel has to be gated at three places on the hub and. 1. As these flow fronts come together on the. 5. 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. in the cavity of the injection mold. 3. Insufficient plasticizing ability of injection molding machine. In injection molding, it is often important to maintain consistent color throughout the part. 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. The weld lines that occur in injection mouldings are critical areas on which depends on the strength of the mouldings. In an injection molding process, a weld-line forms when two flow fronts meet each other. Fatigue crack growth (FCG) tests were conducted on SEN specimens prepared from 100 mm. Figure 1 below shows the development of a weld line. As a result this. 015 0. In a meld line, the plastic comes together at an angle greater than 135 degrees. 6. 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 are a kind of Achilles heel of plastics. At a low volumetric injection flow rate of 33. Star Rapid offers tips and tricks to improve your prototypes and production parts. Many researchers had emerged with several. In this regard, the plasticizing ability of the plastic injection moulding machine should be checked. This article will introduce you the usage, types, and advantages of the Sequence Injection Timer. [8,9] It is capable of. 4. Information about PA6/PA66 (Nylon) Injection Molding. This month, in our FREE SimTech™ series of webinars, we will explore weld lines and how they develop. Injection molding of large/complicated products are usually prepared by multiple compounds, which produces weldlines once the melt fronts are joined by impingement flow. open access Abstract Micro weld lines are the common problem that occurs for plastic molded parts through injection molding process. 025 100 120 140 160 180 200 220 240 Mold Temperature (F) LDPE PPAbstract. 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. In this paper, two different injection molding tests were completed. The weld line in an injection molding product can significantly impact the strength and durability of the last part [12] [13][14][15]. Bin-Xin Yang Ouyang Jie Supei Zheng Qiang Li Wen Zhou. Injection molded plastic parts have comparatively less strength in the weld line section and they also have an impact on product aesthetics. Slow down injection speed. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. They are the result of fundamental physical effects taking place inside of the mold tool cavity. Weld line is one of the plastic injection molding defects. Which means engineers need to know how to account for this phenomenon in an efficient way. Weld line injection molding troubleshooting. There are several possible causes that need to be investigated to troubleshoot weld lines in injection molding. The most common and one of the most challenging injection molding defects are weld and knit lines. This paper presents the. Abstract. Low mold temperatures are usually employed to decrease cycle molding time and final process costs; however, resulting surface defects include weld lines, sink. Three terms that often get mixed up are weld, meld, and knit lines. Weld line (also known as a knit 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. une, 13: 15. A weld line can also be called a knit line. Instead, a line that looks like a seam forms. 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). Weld lines can be a weak spot and have therefore to be taken into consideration in part design. Sequential valve gate technology. Wavy lines are another feature of weld lines. Therefore, it is recommended to do a moldflow study prior to the mold being built. 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. 2017-01-0481. During injection moulding, a weld-line occurs when two or more flow fronts collide in the hollow cavity. 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. Learn how to avoid them and what injection molding companies do to prevent them. ac. Abstract. In the heating step, the heatingOverview of the injection molding process. In this case the two flow fronts will meet and there will be very little molecular orientation across the weld. injection molding, (b) weld line and meld line, and (c) injection sample size and shape. Nozzle – The nozzle is at the end of the barrel and contacts the injection mold. 2. Weld lines not only affect the appearance and quality of products, but also cause negative influences on the mechanical properties. Multi-Shot Molding – A molding process that uses two or more plastic materials to form a single part. 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. * Corresponding author, e-mail: [email protected] an injection molding process, a weld-line forms when two flow fronts meet each other. Weld-Line in an injection molded part develops when two or more melt fronts are converged together. (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. Weld lines are a kind of Achilles heel of plastics. + Increase mold temp, or materials’ temp, or holding pressure. If the different flow fronts have cooled. The most simple design modification for eliminating the weakening effect of a weld line is to increase the wall thickness in the weld line zone (Figure 4). Plastic Rapid Injection Molding is popular not only in low volume manufacturing but also in large quantities molding, it is the most common way to manufacture plastic parts. These are caused by the shot of molten plastic moving at different speeds throughout the injection. For multiple gate and complex part, molding weld-lines are unavoidable, therefore mechanical behavior of the weld-line needs to be predicted. Microsyst Technol, 14 (6) (2008), pp. Strength measurements should be made to. The appearance quality of plastic parts in weld lines can be improved significantly through the rapid heating cycle molding (RHCM). These flow fronts occur when the molten plastic material encounters obstacles, such as inserts, ribs, or other features within the mold cavity. This study focuses on the effect of melt temperature on. In order to reduce these weak points, a special ram technique for injection molding, which can be integrated into the mold, was investigated. To position weld-line to avoid critical areas for the sake of aesthetics or mechanical strength is the key to the success of bi-injection molding. As the plastic flows through the mold it. The gate is the critical bridge between the runners (the channels through which the molten plastic travels) and the actual mold. reinforcement type and amount in nylon 6/6. JENIS-JENIS DEFECT (CACAT) PADA PRODUK INJECTION MOLDING PT. Meld lines are formed when two separate flow fronts meets. In this paper, a weld line factor (W-L factor) was adopted to. This occurs mainly in the presence of barriers that divide the melt flow in. Shaofei Jiang. In injection molding weld lines are formed whenever two flow fronts are joined. 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. Lugs size is 65 х 24 х 4 mm. 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. Fig 13:- Detailed view of weld lines. Figure 2. A simulation of mold filling with multi-inlets or an insert in the cavity is pursued with an improved Level Set Method. Nguyen-Chung. , Ltd. Melt temperature does effect the weld. When two or more strands of molten plastics meet in the mold, a weld line will be produced at the junction [1,2]. These potential causes include:Known methods to reduce weld-line effects are the optimization of injection molding parameters, enhanced tool temperature, and using special molding tool devices. Weld line strength vs. Mechanical properties of the weld line defect in micro injection molding for various nano filled polypropylene composites. When this fails to happen correctly, a weld line defect occurs. Bubbles are caused by melting flow fronts colliding in a mold cavity. Weld or Knit lines are a plane or section in an injection molding part where the flow of molten plastics meets from different directions. 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. The results showed that the tensile strength of PE remains unchanged in the presence of weld lines. 4. Investigate for potential contamination. The optimum injection molding parameters to manufacture the product was determined by . Weld-line is a weak area which reduces the strength of the part locally. The welding angle can be used to differentiate weld lines and meld lines. 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. Insufficient plasticizing ability of injection molding machine. If it only affects the appearance, it can change the position of the burn four to change the position of the weld line. The weld line and the flow pattern of co-injection molding can be seen from Fig. Poor weld line Ⅰ. Injection speed is too low. Miron MC, Major Z, Adachi T. 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. (3) Adjust the temperature of the barrel and nozzle: the viscosity. Some of the approaches include the application of machine learning methods (Chen 2008; Manjunath and Krishna 2012; Kuo et al. Islyn Thomas summarized the need for a particular vent location better than I ever could.