Also known as a knit line, this is the point at which two flow formations meet and are unable to. incomplete filling or shorts. 763-755-7575. Still, it can be seen to varied degrees depending on mold. Cooling Lines, Injection Mold Material has a great impact on injection molded part quality. injection molding. Insert injection molding is a process that requires an insert — typically metal — to be pre-placed in the tool for injected plastic to flow around. Injection Molding Process Guidelines The following is given as a potential process starting point. We all know that injection moulding is great for producing both custom prototypes and end-use production parts, but if you are not careful it can cause some. The Demo Mold helps those new to injection molding easily visualize the process and is a great teaching device for educators. placed usually in the areas last to fill, near knit lines, as well as on the runner system. Weld line defects – also known as knit lines – is a defect that occurs when the injected plastic meets within a mold. Thick walls are not recommended because of POM’s high shrinkage rate. There are times when porous materials like Porcerax are used in problem or backfill areas. It recently obtained a $4. Our prototype injection molding process helps you cut product development cycles by weeks—sometimes months—and bridge to production with injection-molded parts within days. All the while, the material could be the correct material," Hill says. This article will look at two common venting options—using traditional machined vents and venting through porous materials—to help you decide which is right for your application. 1990-03-01 00:00:00 Knit lines in reaction injection molding (RIM) are formed when a fluid flow front passes through the mold cavity and must pass around objects in its path. Multiple parts with complex design and differing wall. This line does not normally impact the overall shape or dimensions of the item. 2. For example, increasing gate size can improve part filling. While injection molding itself is a straightforward process involving melting. Inappropriate temperature. such as knit lines and other imperfections. 2. Weld or Knit lines are a plane or section in an injection molding part where the flow of molten plastics meets from different directions. Increase the injection speed. 5. Corrosion resistance. This makes the casting process as efficient and accurate as possible. Knit Line occurs where different flow fronts of material meet while flowing through the mold. 040 and 0. When designing for injection molding, consider these steps to prevent knit lines The Resin Cooling Process. Injection molding, producing, and forming resin materials are three core components of injection molding technology. The Difference Between Knit and Meld Lines–and Why It Matters. Core out parts to eliminate thick walls. This summary represents a key subset of the detailed molding information found in the remainder of this molding guide . The relationship between processing conditions, morphological structure and mechanical properties of knit lines of an injection molded semi-crystalline thermoplastic. Disadvantage: May rust if improperly stored. Injection Molding Materials When using PolyJet molds, both tool life and part quality will be dependent on the thermoplastic material used during the injection molding process. As. If life safety is involved, or reliably or efficacy are absolutely required, every part should. In plastic injection molding, a parting line is where two halves of a mold meet when closed. Based on the resin temperature, filling speed, and resin, there is a variation in the knit lines. Monoform parts. These flaws can affect the aesthetic and structural integrity of the. The melt is forced to split up during filling of the cavity. Understanding Knit Lines in Injection Molding: Causes and Solutions. (If parts are to be molded by Protomold’s rapid injection molding process, our Design Guidelines should be used. Flash: All plastic injection molds contain parting lines, which create the potential for small amounts of molten plastic to escape the mold cavity’s boundaries. TRADITIONAL MACHINES VENTS. On the opposite side. The knit lines are the result of poor molding conditions (likely molding at too low of a temperature). Injection moulding can be performed with a host of materials mainly including metals (for which the process is called die-casting ), glasses, elastomers, confections, and most commonly thermoplastic and. Learn how HPP maximizes these specialized processes. 5 mm) is ideal, according to injection molding engineer Jack Rulander of Protolabs in Maple Plain, MN. knit line. Changing the. holes, multi-point injection. This can dramatically reduce the effects of material changes, according to the injection molding technology company. Flash: All plastic injection molds contain parting lines, which create the potential for small amounts of molten plastic to escape the mold cavity’s boundaries. . Give us a call at (425) 339-0288 or email us at info@sealectplastics. Molding is a manufacturing process in which resin in a barrel is. Knit lines, also known as weld lines, are fine lines that resemble hairline fractures or cracks. A poor knit line can cause only cosmetic blemishes or it can significantly weaken the structural integrity of a part. Contact Universal Plastic Mold Today. Bubbles are caused by melting flow fronts colliding in a mold cavity. Mold Venting. Degassing – Degassing is the simple operation of opening and closing an injection mold to allow any trapped air (or gas) to escape. Venting. 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. extend mold service life. Gating. One common problem that occurs in injection molding is the formation of knit lines. ” What else can you do about weld lines—besides redesigning the mold or gate locations or adjust the flow pattern during fill with sequential valve gating? I recently saw a report on this issue from Moldex3D, the maker of molding simulation software. (1987). What causes knit lines? Knit lines are formed when the molten plastic flowing into the mold cavity runs into an obstruction, such as a core pin that forms the through hole on a flange of an enclosure. Reduce the injection pressure. Thicker parts require more cooling time and can lead to air becoming trapped in the mold and weld / knit lines to form. 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. This is a video excerpt from our Problems & Solutions Course - Weldlines. Reducing the size and depth of depressions helps minimize the impact of knit lines. Check the diameter of the ejector pins and the pin hole tolerances, if the tolerance is too wide this could allow molten plastic to flow down between the pin and hole surface. He said, “Vent cavities at weld lines or junction points where two or more material streams meet and fuse into a solid mass. Reduce the injection pressure. Injection molding is the most cost-competitive technology for manufacturing high volumes of identical plastic parts. 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. The parting lines is where the two injection mold halves (A side and B side) meet. ITAR. Randy Kerkstra has been in the plastics industry for over 26 years, occupied frequently with. They appear around holes or seams of an injection molded part, and some may call them “flow lines” or “weld lines”. The company provides an array of digital manufacturing expertise. Adjusting features to be suitable for molding will help resin flow well into the mold, allow it to cool evenly, and reduce the chance of cosmetic defects such as sink, knit lines, flash, and warp. Observation on a “trial and error” basis may be required. Flow Lines. During the injection molding process, molten plastic is injected into a mold cavity through a gate. Knit Lines and Resins. Once the plastic sets, the mold opens to eject the product. ABS. Weld line defects – also known as knit lines – is a defect that occurs when the injected plastic meets within a mold. Knit lines, also known as weld lines or meld lines, are visible lines or seams that appear on a molded part where two or more flow fronts meet during the injection molding process. To learn more about us or to get a quote, click here or call 1. Injection molding is min-maxed for mass production. - Mold flow analysis to control fill and knit lines. Complex parts can be reproduced with low cost once mold is manufactured. Knit lines, also known as weld lines are areas in the molded part where two or more flow fronts converge. • Estimated clamp tonnage of 5. Usually the parting line of the mold is perpendicular to the mold opening direction of the injection molding machine. Compression molding can also support large part sizes, and it has a tendency to. 01 inches between parts fitted together to work best. The gate is the entry point to the part-forming cavity, where plastic material is injected from the molding machine barrel, through the sprue and runner, into the mold. Weld Line defect analysis, the most common of many defects in injection moulding products. 4271. They again get resolidified along the surface. A screw-type plunger forces the material into a heated chambe r,. It is best practice to maintain a uniform thickness throughout an injection-molded part. As the polymer resin is injected into a mold, it flows through all parts of the mold. Not always a problem, but can cause serious structural issues. Injection molding is a popular manufacturing process used to fabricate parts in large volumes. Change gate locations. Once the mold is created and the machine is set up, additional parts can be manufactured very fast and at a very low cost. Knit lines, weld lines, mold lines, or flow lines in injection molding are faint lines that become visible on certain plastic parts. Steps involved in Multiple Material Molding. To prevent swirling, perform tests whenever possible and use pre-compounded resin to ensure identical color match across parts. The chart below shows recommended wall thicknesses for common injection molding resins. TEFABLOC™ TOSI 431 75A is a high-flow thermoplastic elastomer (TPE) designed for large-part injection molding applications, offering exceptional flexibility and weather resistance. Meld and knit lines are actually both different types of weld lines. Weld Lines-3 Ways for Detecting and Correcting. Weld lines are also known as “stitch lines” or “knit lines”. Injection molding is an efficient, often cost-effective way to manufacture custom plastics that are strong, durable, and long-lasting. Users will be able to use in-cavity pressure or temperature sensors to control when the valves open or close. The mold’s sprue bushing and locating ring is placed in a way that makes sure the injection molding nozzle is properly aligned and centered. Self-mating parts. Trapped air in a mold manifests itself as a burn mark on the molded part. To learn more about us or to get a quote, click here or call 1-888-893-1587 now. They again get resolidified along the surface. Knit / Weld Lines. Kim, who has worked for hot runner system and auxiliary equipment supplier Yudo-Abiman for 12 years, most recently as. As the melted plastic fills the mold, there are locations where the molten plastic flow stream separates and then comes back together. These lines usually occur around holes or obstructions and cause locally weak areas in the molded part. Call 800-985-6750 or email your inquiry to sales@customgasketmfg. Mold flow analysis is a software simulation that can show how resin will fill the mold during the injection molding process. 0 and Table 1). To account for variations in viscosity, nylon injection molding machines need to maintain an appropriate injection pressure. Dabei erreichen unsere Produkte zufriedene Käufer in mehr als 30 Ländern. Injection molding is the most widely used method for mass-producing plastic parts. The injection molding process uses a granular plastic that is grav ity fed from a hopper. This course outlines mold filling and how different gating configurations affect filling. For non-reinforced or non-filled nylon, the mechanical performance in the knit lines (planes) areas are approximately equal to the mechanical performance of the resin (polyamide) used. Knit Lines. He is currently a tooling manager for a large, multi-plant molding and manufacturing company. Knit lines form when two or more plastic flow fronts collide and solidify or “knit” during the molding process. We all know that injection moulding is great for producing both custom prototypes and end-use production parts, but if you are not careful it can cause some. Weak weld lines are perhaps the most common and difficult injection molding defect to eliminate. Different plastics make different types of knit lines. Thick sections take longer to cool than thin ones. TRADITIONAL MACHINES VENTS. More about the knit lines in injection molding. PCS says each module of the Polimold Valve Gate Sequencer controls two zones, with the option to control up to 14. com Discover why you should avoid knit lines when designing and manufacturing injection moulded parts. Molding Troubleshooting Guide Bond Readout Bond readout is a surface distortion similar to a hump or sink that occurs over a bond line Probable Cause Material Process • Mismatch of compliance between outer panel, inner panel and adhesive • Incompatible thermal expansion coefficients between the SM and the adhesiveIt tells them that you visualized how injection molded parts cool and harden. Computer simulation packages of injection molding have had success in predicting filling behavior in extremely complicated geometries, capable of predicting weld lines’ location exactly. Mold venting is critical to the quality and consistency of the finished part. weld lines may form during the injection molding process and work closely with the plastic injection molder and tool builder to choose the best possible gate location. A plastic product formed by the injection mold is divided into two parts, and the line separating the product is called the parting line. Weld Lines-3 Ways for Detecting and Correcting. RELATED CONTENT. It is caused by the incomplete joining of the uncured. Three terms that often get mixed up in injection molding are weld, meld and knit lines. Weld line in injection molding is line where two or more flow molten plastics knit together. An edge gate introduces material at the main parting line, or where the two halves of. As melt temperature, viscosity and abrasiveness rise, tool life will decline. (See Fig. These are caused by the shot of molten plastic moving at different speeds throughout the injection. Get a free des. Injection Molding Press. The quality of the answer is directly proportional to the information we have to work with. These materials have beenThe wall thicknesses of an injection molded part generally range from 2mm – 4mm (0. Increasing injection speed. occupied frequently with troubleshooting injection molding. Contact Universal Plastic Mold Today. Even parts with metal inserts can be produced. The linear mold shrinkage of injection molded parts will vary from 0. Swirling can increase depending on the material you use, and the texture or polish of injection molding tools. 1. The quality of the answer is directly proportional to the information we have to work with. Meld and knit lines are actually both different types of weld lines. (2) Undesired movement of certain materials in a plastic. In addition, the force of the gas holds the appearance side of the part in contact with. Mold bases, ejector plates, and some cavities (if nickel or chrome plated to prevent rust). But we can’t talk about the injection molding process without discussing the injection molding machine. land and using maximum vent depths to get them as close to self-cleaning as possible. From the start of your project, you can count on The Toolroom to exceed your expectations for all of your plastic injection molding needs. Over the years, I have developed two separate “5M” systems. These include: Symmetrical parts. It happens when the molten plastic material flows around obstacles, such as inserts or cores, and rejoins on the other side. In fact, knit line strength will decrease with higher filler content and with longer fibers. Knit Lines and Resins. As a result, a rib at the weld line junction can strengthen the bosses at the mold line. ABOUT THE AUTHOR. Table 2 lists the<br /> properties of common tool steels and the typical mold components for which they are<br /> used. The most common and one of the most challenging injection molding defects are weld and knit lines. Prevent Flow and Knit Lines During the Injection Molding Process. Trapped gas is one of the most common causes of part burns, and it can also lead to short shots and voids, blemishes and discernible knit lines that weaken the part. Knit lines, holes, part configuration and the talent of your molder all come into play. Hartland, WI 53029. 1-3). From the start of your project, you can count on The Toolroom to exceed your expectations for all of your plastic injection molding needs. Injection speed and pressure. These defects are not visible, like small. Other common issues associated with thin walls include uneven cooling, warp, cracks, cosmetic texture inconsistencies, and weak knit lines or fracture points. More about the knit lines in injection molding. knit line formation, application of draft angle and design for assembly. When designing for injection molding, consider these steps to prevent knit lines Resin cools as it is injected into a mold. In the injection molding process, knit lines are a common occurrence when two or more plastic flow fronts collide and solidify, resulting in a visible seam or line on the molded part. Learn Injection Molding Glossary with Plastopia: Using actual molded parts (with images) as examples. So. 08 KICKOFF PRODUCTION. Knit lines form when two or more plastic flow fronts collide and solidify or “knit” during the molding process. With over 50 years of experience, Universal Plastic Mold can help you avoid (or at least minimize) knit lines in your molded parts. Depending on the resin, resin temperature, mold temperature, and filling speed, knit lines can vary from virtually invisible to something that looks like cracks in the plastic. Be wary of saving too much weight or you might end up with: cracking. In a plastic injection-molded component, a knit line occurs when 2 different plastic flows emerge in a mold. [8] Bevis, MJ, Reis RL, Cunha AM. Three terms that often get mixed up in injection molding are weld, meld and knit lines. The thermo-rheological findings were used to investigate the sources of weld line weakness. Core Geometry. Gates, vents, sliding cams, pick-out inserts, and any other place where the two sides of. Sequential valve gate technology. Knit lines, weld lines, mold lines, or flow lines in injection molding are faint lines that become visible on certain plastic parts. This radius should not be smaller than 0. Proper venting is essential to molding a defect-free part. Find out more by calling 573-437-4154 today or email us. As. Timing and temperature are significant contributing factors when it comes to flow and knit line defects. While mold-filling simulation is a very common tool for predicting the fill patterns of an injection mold, in our judgment there is not yet a commercially available, satisfactory filling simulation for microcellular foam molding. What causes knit lines? Knit lines are formed when the molten plastic flowing into the mold cavity runs into an obstruction, such as a core pin that forms the through hole on a flange of an enclosure. 012 in. 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. (1. 020"). Moisture in the material due to insufficient drying can form at the melt front, forming an interface between the two melt fronts. Heat: Too much heat can have an appearance similar to moisture splay. The result is a consistent flow of molten plastic during injection and a quicker filling time. They occur when melt flow fronts collide in a mold cavity. As the melted plastic fills the mold, there are locations where the molten plastic flow stream separates and then comes back together. On a hydraulic machine you can program hold pressure: For example, if you set 850 psi (59 bar), you will get 850 psi hold pressure for the time you set on. It can be determined by a visible line appearing on the surface of the plastic part where two flows of the plastic meet. In injection molded parts, there are 2 types of weld lines: The first type of weld mark is called cold-melt joints and is formed when the melt front enters the cavity with different gates. occupied frequently with troubleshooting injection molding. By altering the part design, it may be possible to just have one flow front, and avoid multiple flow fronts having to come together. Fortunately, there is a technique that provides almost unlimited control over which parts of a tool fill when and how fast. Weld-lines look like cracks on the appearance of plastic. Gates, vents, sliding cams, pick-out inserts, and any other place where the two sides of. It is. Increase the injection speed. By contrast, a slow injection speed will give you a matte finish and a cold mold, such as 50F, will give you a more flexible part. For over four decades, our experienced team and leading edge technology have provided you with tooling solutions from start to finish. A mold with too few gates is susceptible to cooling problems, but a mold with too many gates. CNC-Bearbeitung; Spritzgusswerkzeuge und -teile; Stereolithographie (SLA) Selektives. Weld lines typically appear in a part when an obstruction of some kind separates the melt flow and prevents it from "knitting" together. Injection Molding: How to Set Second. Multiple gates will always. molding run to be sure that the temperature does not exceed the recommended limits . So much. Weld-lines or knit-lines are formed during the mold filling process when the split melt flow fronts meet at the same downstream location. It explored the use of. Also known as weld lines, knit lines. 008 in. Fictiv can help you avoid injection mold design and plastic part design for injection molding problems. When working with customers, our design guidelines for living hinges are 0. Also discussed are weld and meld lines and their effects on molded. For instance, three widely used processes are insert molding, overmolding, and undercuts. Plastic injection molding has long been an affordable and efficient process for producing custom prototypes and end-use production parts. In this phenomenon, some portions of the mold cavity are filling, while others undergo over. An option to bluing agents, the long established means of gauging pressure distribution, comes via Pressurex, a thin, flexible, plastic film. 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. The melt is forced to split up during filling of the cavity. Solution: People. Optimizing Mechanical Performance of Injection Molded Multiple Gated Rotating Thermoplastic Components: Part 1 - Consideration of Structural Analysis and Knit Line Effects March 2001 DOI: 10. Injection molding is an excellent way to create plastic parts in bulk, but there are many problems that can cause cosmetic defects ranging from minor to major. Services. Injection molding is an excellent way to create plastic parts in bulk, but there are many problems that can cause cosmetic defects ranging from minor to major. They need the interference of about 0. Learn how material selection, part design, and optimizing process parameters can help eliminate knit lines. These defects are not visible, like small. May 24th, 2019 Posted in Injection Molding Flaw Repair Preventing Flow Lines, Knit Lines, & Blush Injection molding isn’t an exact science, and there is a lot that can go. This type of molding uses a single tool to create both the part's geometry and surface finish in one step. From Plastic Materials and Processing by A. The example. This production method is particularly popular when manufacturing in large quantities. It happens when the molten plastic material flows around obstacles, such as inserts or cores, and rejoins on the other side. What Are Knit Lines in Injection Molding, and How Do You Prevent Them? - RJG, Inc. RJG announced that its injection molding process control system, CoPilot, will begin offering valve gate control technology for hot runners starting in September 2021. a knit line will form 180°on the opposite side from the gate location. Most failures occur at what are called “weld lines” or “knit lines”. This can enable the manufacturer to increase the molten plastic temperature at the front of each flow and avoid the occurrence of weld lines. Obstructions in the part create weld lines or knit lines during injection molding. As a result, prototyping is strongly recommended for parts with. Three terms that often get mixed up are weld, meld, and knit lines. It’s economical, efficient, and can produce simple to complex parts with low waste. . A weld line can also be called a knit line. In situ injection molding of continuous fiber reinforced thermoplastic composites is challenged by unbalanced dual-scale infiltration flow due to the pronounced capillary effect. The difference between a knit and meld line is significant, dramatically impacting the part’s structural integrity. "As soon as that part or material is stressed, it can be real conducive to fracture, cracking, breaking, just because of the way it's been molded. Product designers encounter a wide range of challenges when creating and developing molded parts, such as stress factors, warp, and those pesky knit lines. 030 and 0. This configuration positions the injection mechanism at the top of the mold, allowing gravity to play a role in filing the mold cavities. RELATED CONTENT. A weld or meld line is a weakness or visible. The mold-opening force varies widely depending on the type and size of the molding machine. Weld lines defects are formed when two flow fronts are merged together. 344. Shorter knit lines must equate to a stronger part. Having a basic understanding of the injection molding process will aid in understanding how to design for injection molding as well as how to forecast production schedules. They need the interference of about 0. Weld lines: Also known as knit lines, these are molding defects that occur when two flow fronts meet without the ability to “weld. It is best practice to maintain a uniform thickness throughout an injection-molded part. The area generally has lower strength than the other areas of the part. Islyn Thomas summarized the need for a particular vent location better than I ever could. Weld lines are formed when there is an inability of two or more flow fronts to ‘knit’ or ‘weld,’ together during the molding process. Still, they are almost always a cosmetic issue. See UNDERCUT. Reduce the injection speed to limit the risk of trapping air inside the mold. Proper mold cooling can eliminate warp, decrease cycle times, and increase part quality. Wax Cold wax Increase wax temperature. When injection molding complex parts, often knit-lines are formed during the mold filling stage. Knit lines; Knit lines always occur once 2 melted materials meet with hair-like discolorations. Reduce the temperature of the mold and plastic being injected. Edge gates, which can include fan and tab-shaped gates, are the most common ways to gate a tool. We wanted to independently assess how a mold would fill and where knit lines would be, instead ofKnit Lines. Weld lines, knit lines, and meld lines are terminologies to describe the imperfections of finished parts in plastic injection molding processing. In the injection molding process, knit lines are a common occurrence when two or more plastic flow fronts collide and solidify, resulting in a visible seam or line on the molded part. Venting is required to allow the air in the sprue, runner and cavity to leave the tool as the melt flows into the cavity. . Finally, knit lines occur when molten plastic flows around an object and rejoins on the far side, a phenomenon that is quite possible when inserts. Knit lines, also known as weld lines or meld lines, are visible lines or seams that appear on a molded part where two or more flow fronts meet during the injection molding process. They occur when melt flow fronts collide in a mold cavity. 7. Weld/Meld/Knit lines are all terms describing the effect of two or more flow fronts of material joining or meeting together in the part. When injection molding complex parts, often knit-lines are formed during the mold filling stage. What you should know is that there are various failure modes for injection molding. These data were obtained from many andKnit lines in injection molding are common defects of the molded parts. This guide to thermoplastics and injection molding material selection is aimed at an engineer who plans to quantitatively analyze a part, determine loads, stresses, strains, and environments and make an optimal material decision based on the analysis. When venting stationary inserts or core pins in rib or part details with venting issues, I recommend no more than 0. Weld lines are a common imperfection to be found in most plastic injected molded parts. It’s our responsibility to make sure your design comes out of the mold working properly. A meld line occurs when two moving melt fronts converge and flow parallel to each other. 1050 Walnut Ridge Drive. Figure 1 Flow Lines Knit or Weld Lines Cavity Gates Table 1 Knit line in a multi-injection-point cavity. The packing pins are sequentially. 5 to 3. mixed manually and quickly stored in the tank of an injection machine just before the start of the resin injection or (2) the components are stored separately in different tanks of an injection machine with a mixing head. Nicolet Plastics LLC. The injection molding process offers a vast array of plastic resins to work with. Demo Mold. Weld lines may appear like seams or scratches, but that is not what they are. Injection molding can be a real challenge if you don’t follow the “Five M’s”: Man, Mold, Machine, Material and Method. Main causes of knit lines in injection molding: 1. Second, the runner leading to a tab gate takes up real estate within the. A. Plastic melt and mold temperature. The best we can hope for is to pressurize the knit or meld line better through the combination of melt temperature, mold temperature, flow rate, and holding pressure. But any. Below is a list of items that should be checked both during normal molding operations and if defects are detected. In the injection molding process, knit lines are a common occurrence when two or more plastic flow fronts collide and solidify, resulting in a visible seam or line on the molded part. How weld lines form. Injection molding a part with Class-A surface finish and ribs or bosses has proven an elusive goal for molders, despite their best efforts with conventional injection or internal gas-assist technology. Injection molding is a popular manufacturing process used to fabricate parts in large volumes. The last cause of flow lines may be the operators running your daily operations. We ensure customers receive accurate, fast, on-time, sufficient support and services. 3. Behind the obstruction, the flows try to merge again, but this is made more difficult by a low temperature of the mold surface and a low melt pressure. Gating. 3D printed molds in the injection molding process to lower costs and lead time. What is copper electrode in injection mold? hashtag#plasticinjectionmold hashtag#moldmaking "Copper electrode," also known as "electrode," is a common component in mold manufacturing. Notched weld lines then remain near the cavity walls. A weld line, also known as a knit line, is a visible line or mark that occurs in an injection-molded part where two or more melt fronts meet and fuse together during the molding process. 080" – 0.