Appearance alone cannot tell you which type of splay is present. 00 Select options; Atlanta, GA. This can result in bubbles or splay in the molded part. There are three ways to mold. Medical Dictionary for the Health Professions and Nursing. Burns in injection molding are, quite literally, burns. Symptoms/problem: Swirls and gloss on the part’s surface. Ai-powered technology is ideal for cosmetic visual inspection of subcomponent assemblies. Place vents at last place to fill and at converging flow fronts. • Visual inspection, trimming, and packing of injection molded plastic products. Injection molding moisture steaks or splay marks solution. Remedies: Vent the mold by grinding thin (0. The issue may be as simple as your material flow. John Bozzelli is the founder of Injection Molding Solutions (Scientific Molding) in Midland, Mich. The most common cause of blisters resulting from material issues is that the material is not dry enough when it goes into the melting process. plastic injection moulding 5. Paul Mastro is a plastics engineer with over 30 years of experience in the formulation, injection molding and. High-quality mold should be used in injection molding to avoid molding splay. Remedies: Increase the injection fill speed in small increments (two percent of total) until the delamination tendency disappears. Gate size. Warping. Splay happens during the injection molding process due to the presence of gas or vapor within the molten plastic. The most common of these methods are the hot air dryer, desiccant dryer, compressed air dryer, and vacuum dryer. There are many "lookalike" defects, plus many conceivable causes of splay, including excessive mold lubrication. building; 35 molding machines;Injection molding Troubleshooting guide. Synonyms for splay and translation of splay to 25 languages. Injection molding moisture steak. Splay (also called chicken tracks, tails, and hooks) is usually caused by a gas, usually water (steam), but can be caused by unmelt, dirt, chips, or flakes from three-plate molds, cold slugs, excessive volatile additives, air, and/or decompression. If it’s a void, the wall stock will collapse and show a sink. Clamp force estimation. Symptoms: Blush at the gate, shear splay on the top of the part, and screw slippage on the molding machine. This is an excerpt from Lesson #6 in Paulson's Injection Molded Part Problems and Solutions training progam - Splay (or Silver Streaks) and how to fix them. It's recommended that the minimum L/D used in injection molding be 20:1. Splay or Steam typically visible streaks or bubbles in or on the end-product caused by the boiling of the moisture in the pellet that becomes gas/steam. This line is known as the partingSplay is a cosmetic defect that occurs to plastic injection molding, for silver or white smears appear over the surface of the part. Injection Molding Extrusion Blow Molding Molds & Tooling Manufacturing Recycling Additive Manufacturing Features Thermoforming Compounding Rotomolding. The Society of the Plastics Industry [spi] PDF Price. Smooth out the corners and sharp turns in the mold design to avoid sudden changes in melt flow. Remedies: Use an injection screw with the proper compression ratio. Splay is characterized by light colored streaks in the part that usually follow the direction of the melt flow. Excessive injection pressure creates stress that causes product warpage in the mold. Low Gloss. See moreSplay is a common defect in plastic injection molding that can be caused by moisture, shear and heat. Sink marks usually occur when there’s a shrinking of a molded component’s inner part. Injection Molding Skills & More. The molten material could be metal, glass, rubber, or plastic. (2) Reduce the barrel temperature. It may not necessarily produce visible splay, as the water is consumed in the hydrolysis reaction. It usually appears at the gate where the plastic enters the mold. The root cause of sink marks is a difference in cooling time between the. Read our blog post here. The pressures used to inject molten plastic is tremendous. Dri-Kote works for most injection molding needs. Sink Marks. This is an excerpt from Lesson #6 in Paulson's Injection Molded Part Problems and Solutions training progam - Splay (or Silver Streaks) and how to fix them. rubber injection moulding 6. There are many "lookalike" defects, and more possible cause of splay, including excessive mold lubrication. Splay be ampere cosmetic flaw that occurs in plastic injection molding, when silver or white streaks seem on the surface concerning aforementioned part. Thicker mold walls enhance the formation of foam. Pack/hold: 150 psi vs. The three main causes of splay are heat, moisture, and shear, with heat being a primary culprit. This position will be based out of our New Automated Injection Molding plant located in Pineville, NC. If you turn on the spigot to a garden hose, you will hear a hissing sound at the nozzle end for the first few seconds. There are many "lookalike" defects, and many possible causes is splay, included excessive mold lubrication. 1. Generally 70% to 90% of the energy necessary to melt the plastic comes from this compressing, friction, and screw-rotation combination. This is an excerpt from Lesson #6 in Paulson's Injection Molded Part Problems and Solutions training progam - Splay (or Silver Streaks) and how to fix them. R2:PET Preform Mold was damaged. Under normal circumstances, the molten plastic fills the mold cavity in a “fountain flow” manner, as shown in Figure 2, which depicts the “fountain. The J-ADS Superior series machine offers unmatched shot-to-shot consistency and incredible reliability. 0005''-0. 2. Learn what appearance the purge puddle should have to identify that the material is ready for injection. It provides a clear, free-flowing path for plastic granules, powders, and liquids (such as liquid color) into the feed section of the screw. This extra effort ensures that their injection molding process is smooth and free of splay defects, resulting in high-quality finished parts. Contamination can be defined as an imperfection in a molded part caused by the presence of a foreign object or material that is not part of the original molding compound. Haze develops when PET in either injection or blow stages is heated beyond about 115°C (240°F) and allowed to cool down for even a short time. Slip agents not only reduce the coefficient of friction (CoF) but also are used to reduce adhesion between the mold and injection molded polymer. applications. pdf - Free download as PDF File (. Blisters can be defined as raised defects on the surface of a molded part caused by trapped gases in the part that could not escape before the surface began to “skin”during the molding process. Splay can be more obvious on black parts, but this plastic molding defect can be found in pretty much any injection molding material, any color. January-October 2022, exports of plastic products amounted to $89. Over the years, I have developed two separate “5M” systems. Ada banyak penyebab yang lebih mungkin, tapi perlu informasi lebih lanjut dan benar Cacat jenis sebenarnya injeksi. Injection molding can be a real challenge if you don’t follow the “Five M’s”: Man, Mold, Machine, Material and Method. Key takeaways: Properly dry the polymer material to eliminate excess moisture. “Splay,” which refers to a specific flaw that emerges on the surface of molded objects, is. Injection moulding process explained with key elements. Possible Causes & Remedies: Machine Cause. A mold temperature of between 80-120℃ / 176-248℉ should be maintained to prevent sink marks. Plastic injection molded parts can be surface finished from matte to highly polished. COCs low shrinkage, lubricated grades and mold. 375 inch; shorten the gate land to no. Appearance alone cannot tell you which type of splay is present. Parts stick in the mould, Flash, Poor Weld Lines, Burn marks, Short Shots, Pit Marks. Purpose. 1 Overview of Splay Defect Splay affects. (3) Check if the heater and thermocouple are working properly. 4. As mentioned above, the gate size is a measuring act between filling the mold exactly and keeping the smallest runner possible to improve shearing when the mold cycles in the machine. There are many "lookalike" defects, and many possible causes of splay, in excessive mold lubrication. It is made from stainless steel. Allows you to accommodate a variety of part sizes. Teach continue info how to identify and handle splayThese materials tend to generate higher surface resistance during the molding process, creating drag and turbulence that may be reflected in the part appearance—glass fibers, for instance, can add a stringy or sparkly finish to a textured part, while flame retardants might lead to the whitish streaks known to plastic injection molders as splay. Custom Plastic Injection Molding - Troubleshooting Techniques - For this part of this series, we will start out with a very basic injection molding problem and some possible ways of solving it. spe western sections annual pacific technical conference and technical displays/1979/costa mesa ca; usa; da. txt) or read online for free. He is a well-known columnist for magazines covering this area. . For specific questions or more information, please email. Splay Splay is a cluster of breaks, mars, or marks, visible on a plated part. Solution: Ensure the nylon is properly dried; increase dimensions in edge gate, sprue O-diameter, and nozzle orifice; relocate edge gate to the center. Get more about as to id and address splayHow to deal with splash marks. The problem could be the result of machine settings made before the gate was installed. Through intensive machine time and use of our unique injection molding simulator SimTech™, ProMolder 3 is the most thorough and technically accurate training available. Learn how to identify and fix splay with Nanoplas products and troubleshooting guide. Symptoms: Blush at the gate, shear splay on the top of the part, and screw slippage on the molding machine. The three main causes of splay are heat, moisture, and shear. Figure 2 shows the part after testing, and you can now see a depression or sink. It is a cosmetic defect typically appearing as an off-color streak, often silver in hue, along the surface of the molded part. Increase the mold temperature and reduce the barrel temperature for injection molding of thin-walled products. the lip ejection position / pressure is too large → adjust the ejection position / pressure to the appropriate state. It is. Warping: A deformation where part surfaces or walls twist or bend as the part cools. One of the most common defects in plastic injection is splay. Splay happens during the injection molding process due to the presence of gas or vapor within the molten plastic. While the. Hold time. April 5, 2017. One of the most significant advantages of injection molding is the natural surface finish of molded parts. Viscosity: Definition Viscosity as it relates to plastic injection is the measurement of how thick or thin a material flows. The injection molding process offers a vast array of plastic resins to work with. The majority of plastics can absorb moister from the air, meaning they are hygroscopic. . Symptoms/problem: Swirls and gloss on the part’s surface. Gas Marks Defined. Protrusion of the. Take a good look at part design. Remedies: Mold design: (1) Add an exhaust system to a place where the exhaust gas is easily generated. Splay is a cosmetic defect that appear in plastic injection moulding, when white instead. The Troubleshooter’s notebook. . They look alike and each can have multiple specific causes… which mean as many potential solutions! Learn a systematic method and: What are the Causes of Splay in Injection Molding. Drying Considerations For both virgin and rework, hopper dryers sized to afford theThere is also a secondary reason that if the product is too thick while the gate is small, the actual filling speed will be slowed down, which tends to cause flow marks. The linear mold shrinkage of injection molded parts will vary from 0. As a raw material for injection molding, HDPE is an excellent choice. It requires a significant capital investment and a relatively long lead time to machine the tools. Increase the injection speeds: Lower injection speeds cause premature cooling. The molecules bond together as desired and splay is eliminated. These injection mold coatings are applied either in your tool room or on the press and give exceptional release characteristics to the part in the mold, allowing it to eject without sticking and thereby eliminating any pin push marks. Multiple gating, higher flow rates, and gate resizing along with higher material temperatures, may improve merging, move lines to non-cosmetic locations, or provide more uniform cooling temperatures to bring materials together before solidification. SPI (Society of Plastic Industry) has defined a standardized surface finish for injection molds to facilitate industrial designers, design engineers,. This type of injection plastic defect occurs as small depressions or recesses. Answer: The trapped gas ignites from the heat generated by pressure. Injection Molding Know How. However, you can make small changes to your injection equipment and processes to help you decrease the number of flaws that result from the injection molding process. Splay is one cosmetic defect that occurs in plastic injection molding, although silver oder white streaks appear on the outside of the part. 0:1. Injection Molding Know How. 3. While small gates may provide a nicer appearance. Please call 814-898-6103 or email [email protected]. A purge compound can be a great solution before pulling the tool. 00. injection molding process was carried out by varying important processing parameters of mold temperature, injection speed, packing pressure and melt. A Plastic Injection Molding Process Problem – Troubleshooting Methods . It combines the strength and rigidity of acrylonitrile and styrene polymers with the toughness of polybutadiene to deliver superior hardness and toughness. When a rust preventative is over-applied, it can cause grease to break down in certain areas of the mold, leading to bleeding. The Plastic is Cooling Too Quickly: The presence of jetting might mean you have another issue: plastic is cooling too quickly within the mold. Slower, controlled speeds allow for smoother laminar flow that prevents air entrapment. These are cosmetic blemishes on the part’s surface. Lower melt temperature; The mold gate is too small, injection speed is too fast. . This specification addresses the cosmetic quality of molded plastic parts and related post molding activities. Smaller gates might require a slower beginning-of-fill speed. The process begins with the mixing and melting of resin pellets. . Inadequate support for the sprue bushing can transfer pressure to the parting line, too. 5. Splay is defined here to include any defects that appear as smeared material or bubbles on the part surface, usually oriented in the flow direction. Improve injection time. Let’s first discuss moisture, as most of the time splay occurs because the resin has not been properly dried. Well, what this simply implies is that injection polycarbonate molding makes it possible for you to create a wide range of part sizes. The presence of gloss and/or texture in the tool can make what would otherwise be an exact color match appear very different. If you round up a bit, the viscosity at the fastest speed, a fill time of 0. This cosmetic defect occurs in plastic injection molding, when silver or white streaks appear on the surface of the part face due to air, contamination, heat, moisture, or shear issues. Divide the required shot size by 5, creating 5 stages of injection. One is the injection of a high-velocity stream of molten material into the mold ahead of the general flow front. If the injection speed is too fast, the injection pressure is too high, and the relative movement speed of the melt and the cavity wall is too high. Since the cavity is more than 90% full, not much more plastic is needed. High injection speeds lead to shear splay since the material is exposed to high shear conditions. If the grease breaks down on the slides and lifters, it could become tacky, causing them. 2. What's SPLAY in molding & how to fix it. So what does the 140F mold temperature give us? The molding technician thought the 140F mold water was OK because the data sheet provided by the material supplier suggested mold temperatures from 75 to 180F. Lower the hold pressure fix the PET preform mold. Check out the numbers in the table accompanying the graph. Advantages of HDPE as a Material. This fault，which appears on a great many mouldings，shows an area, generally near the gate, which has an uneven, lined appearance. Reduce injection velocity and record the fill time and pressure at transfer. Bob Hatch is manager of technical service and customer support for Prime Alliance, the Des Moines-based resin distributor. Splay Can Holder; Mold Maintenance. Melt decompression can lead to splay and other visual imperfections. Jetting, also known as jet, worm track, or snake-like pattern, refers to the snake-like curves on a plastic injection molded part along the flow direction from the gate, as shown in Figure 1. Solution: Open the sprue O diameter to at least . Part/material: 33% glass-filled nylon 6/6 disk used in an assembly. If you double the viscosity it would be 4000, five times the. This process is fast, cheap, and helps create vast volumes of identical objects. Using a turnkey manufacturer, who also builds and maintains the mold, can help avoid any costly machining charges or mold replacement. 5 sec for ABS/PC. Bob Hatch is manager of technical service and customer support for Prime Alliance, the Des Moines-based resin distributor. Participating in DFM and mold flow analysis is a good way to achieve this. “Incompatible materials” can be a number of things. Splay (also called chicken tracks, tails, and hooks) is usually caused by a gas, usually water (steam), but can be caused by unmelt, dirt, chips, or flakes from three-plate molds, cold slugs, excessive volatile additives, air, and/or decompression. Splay posted by Mike at 6:13 PM. Molding Problems Trouble Shooter. Except for large parts, you are usually dealing with only a few extra grams. R3:The ejection pressure is too large. Fill pattern animation. Optimize temperature settings of the molding machine to avoid material degradation. With the same gate diameter and injection speed, the higher the viscosity of the resin (the lower the fluidity ), the. This video helps to visually define the different properties of splay. Polypropylene is easy to mold despite its semi-crystalline nature, and it flows very well because of its low melt viscosity. Flow lines are off-color lines, streaks, and other patterns that appear on the surface of a part. 375 inch; shorten the gate land to no. What is Splay? Silver or white streaks appearing on the surface of the part often indicate splay in injection molding. This helps prevent mold release buildup, especially in the problem areas of a mold, which in turn mitigates gas build up. Splay can be a costly problem in the production of your molded components. They appear as a dimple or grooves on the surface of thicker sections of molded parts. Increase the melt and/or mold temperature. Remedies: Decreasing the barrel temperature allows the plastic to stay molten without burning or charring. If the only solution is to use a spray, try our Tuff-Kote and Dri-Kote high-performance mold-release sprays. ) Check Your Machine. The weld line can either be a minor cosmetic issue. Too high hold pressure eccentric gate. With the world's top class "high cycle performance" at the core, we have realized stronger and more evolved. The moisture and volatile content in the raw material is. The material temperature is too high, which causes decomposition. Moisture and shear are the two primary. Home; Products. Drying is a necessary preparative step to prevent this defect. A reduction of 10 – 25% is usually achieved in. Learn how to identify the root cause of splay and how to correct it with various solutions. What causes splay in plastic injection molding? Moisture and shear are the two primary causes of splay on an. The following parameters should be evaluated for all projects when conducting a design for manufacturability evaluation in plastic injection molding: Maximum pressure: filling. FIG. When the mold temperature is low, the surface layer will be solidified more quickly, making it more. Depending on the material,. It prevents the granules, etc. 2. To get started with injection molding or get a quick refresher before manufacturing your custom parts, check out our comprehensive guide to injection molding. Injection Molding: How to Set Second. Splay / Shear. Texture. If you were to pour water and molasses at the same time, water would flow much easier than the molasses. (2-3) High viscosity / low fluidity. 4. So what does the 140F mold temperature give us? The molding technician thought the 140F mold water was OK because the data sheet provided by the material supplier suggested mold temperatures from 75 to 180F. Office: +1. Step 3 – Examine the Defective Part and Rule Out Obvious Causes. There have countless "lookalike" defects, and many possible causes of splay, including excessive mold lubrication. Mold vents should function the same way. Increase the venting: Ventilation supplies better flow in the mold. proposed that surface defects, such as splay marks and silver streaks, are. The injection pressure is too high – adjust the parameters appropriately. 1). Whereas conventional injection molding uses velocity control during the filling stage and then switches over to pressure control for final filling and packing, DF uses pressure control only. The most common: incompatible materials. Injection Molding Process. Add more cooling circuits. Use materials with better fluidity (*b) After changing these conditions, the holding pressure actually applied to the cavity will increase, making pitting less prone. The wet material can cause the formation of steam, creating pockets of trapped gas. [1] The most common cause of splay is moisture, which is caught in the resin inside the injection molding machine during the heating. Moisture and off-gases can be a cause of splay. Method of switchover from first to second stage. The defect detection tool then identifies any anomalous parts, detecting both functional and cosmetic defects. A desiccant drier should be used to dry the polycarbonate products to less than 0. First, let’s define the purpose of the feed throat: 1. Sink marks, 2. Watch the YouTube presentation below for information about Plastic411. 5. It offers ways to identify splay causesm and gives solutions on how to correct splay c. sales@uninko. Practical Injection Molding. If burning or flashing occurs, the injection speed is too high and delamination is being caused by other factors. Splay injection molding occurs when the melted plastic material is not flowing uniformly, and it causes streaks or lines on the surface of the plastic part. To decide on the likely cause(s), test each to prove/disprove whether it is causing the. Engineering. COMBINATION MOLD – See FAMILY MOLD. Just like most injection-molding defects, delamination can be caused by one or more of several potential issues. . 4 : 1 and an L/D (length to diameter) ratio between 18 : 1 and 22 : 1 are suggested. Participants are also presented with information and practices on how to best process, document and maintain a reliable scientific injection molding process. 02% moisture. In Figure 1 you can see the bubble; it looks like a gas bubble, right? Most would assume so. Midstate Mold & Engineering. Process: (1) Reduce the injection pressure and speed. conventional injection molding equipment. Purge the barrel amply, to allow the barrel time to heat soak. Cosmetic Specifications of Injection Molded Parts, Revision A. Plastic Injection Molding Defect Guide. In addition, it is important to note that nylon is not only affected by poor drying/ moisture conditions. Category: Injection Molding. Appearance alone cannot tell you which type of splay is present. Michael Sepe is our analyst and author. A mold is filled under pressure with the molten material, then cooled to form a solid part before being removed from the mold. It owns the name silver streak. Advertisement. III. Splay marking. Now, from the machine’s point of view, as the screw reaches the position of switchover, the controller, in something like 0. 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. These data were obtained from many andFor injection molding applications, Eastman Tritan™ copolyester can replace polycarbonate, typically without requiring new tools. Injection speed can also influence dimensional. A desiccant drier should be used to dry the polycarbonate products to less than 0. and T se-Hsi Chen [12. For example, if operators are making a mold of a medical part—like an endoscope, which a surgeon needs to hold with gloves—they will need to develop a uniform texture for gripping. In any case, you’d prefer to create polycarbonate parts of different sizes; then this is the best technique that you need to use. 2) Vents in an injection mold should let the air out, but not the liquid plastic. These are caused by the shot of molten plastic moving at different speeds throughout the injection. injection moulding process 3. Increase the mold temperatures: Cold mold walls prevent material flow. In single-stage molding, overall heat is controlled by holding and cooling time while a change in injection speed can be used to change the temperature in the preform. Splay is sometimes also called “silver streaks” because of the appearance of silvery scratches across the surface of the injection molded part. FOW takes care of all manufacturing tasks in house thus we are able to offer you an accuracy range within 0. 21 Splay Three types of splay are often encountered in injection molding. The Role of Moisture in Injection Molding Splay Defects. Mold leaks also can cause moisture-related splay, so check the mold carefully for any signs of damage or leakage. Midstate Mold & Engineering. Splay can be caused by a variety of variables, and recognizing these sources is critical for resolving and preventing the issue. 11 ref. Splay can be a costly problem in the production of your molded components. FIG. Tel: (60) 3 7890 6399 9am – 6pm (Mon. Trapped air, inadequate drying, high temperatures, and contamination can. The chart below shows recommended wall thicknesses for common injection molding resins. Because we are an ISO-certified medical molding provider. Splay Defects in Plastic Injection. Injection Molding Tuesday, June 27, 2006. injection molding machines using standard industry practices . These are cosmetic blemishes on the part’s surface. Molding Process. This approach will assume you have developed a basic understanding of the injection. com and a consultant/trainer in plastic injection molding. SPLAY in Injection Molding. High nozzle temperatures can promote the formation of thermal splay marks from keeping the. ft. metal injection moulding 7. Splay, a cosmetic defect in plastic injection molding, manifests as silver or white streaks on the surfaces of molded parts, as showcased in the accompanying image. B. Reduce Splay Defects and White Streaks in Your Injection Molded Parts MOS Plastics is a division of KS Group and specializes in high-precision prototyping, injection molding, contract manufacture, and assembly for Healthcare and electronic OEMs. While at the machine, you will be shown basic standard set-up parameters & techniques and how to properly operate the injection molding machine. The pressures used to inject molten plastic is tremendous. Two plastics that can’t. Remedies: Raise the mold temperature in increments of 10 degrees F until the bubbles disappear. 5mm (0. • Ability to recognize molding defects, such as shorts, splay, burns, flash, color swirls, and contamination. 508-520-0011 Fax: +1. Just like most injection-molding defects, delamination can be caused by one or more of several potential issues. splay. Splay is a term used in the manufacture of injection molded plastics to refer to off-colored streaking that occurs when moisture is caught in the material feed, or if the material degrades during processing. Synonimy słowa splay i jego tłumaczenie na 25 języków. This type of injection plastic defect occurs as small depressions or recesses. In some cases, hot manifolds may be. In addition, mold plumbing should be checked to ensure there are no. Wait 30 seconds and record temperature shown on the instrument. Here are 11 common injection molding defects, what the causes are and how you can avoid them. Thermoplastic resins fall into two distinct categories, each with their own advantages and disadvantages. Splay is a common defect in plastic injection molding that can be caused by moisture, shear and heat. , Ltd(XIAOLIN) has 18 years of manufacturing experience, we are an experienced manufacturer for custom rapid prototyping, mold, a. In the process of injection. Here are 11 common injection molding defects, what the causes are and how you can avoid them. To decide on the likely cause(s), test each to prove/disprove whether it is causing the splay, then take the corrective action. 025 inches per inch, depending on the particular resin, molding conditions, part design, part wall thickness, and direction of flow. Packson had g. It is a good practice to place gates and runners in individual inserts so they can be easily replaced and/or reworked. Grippers for Injection Molding; Chemical for Injection Molding. Increase the mold temperature. To prevent parting line mismatch: Clean off any plastic, dirt, or contaminants that could keep the mold from closing correctly, especially behind slides and inside the leader pin bushings. Don't forget to take a step back and take a look at what's going on with your injection molding machine as a whole. Learn other about wie to identify and address splayOn this channel you can get more information about injection moulding machine and processingInjection molding moisture steaks or splay marks solution. Splay is defined here to include any defects that appear as smeared material or bubbles on the part surface, usually oriented in the flow direction. The three main causes of splay are heat, moisture, and shear. Splay is. Primarily, moisture and shear. Tel: (60) 3 7890 6399 9am – 6pm (Mon. MISUMI | Your Time, Our Priority. View my complete profile. The special version of its J100ADS has optional integrated magnetic platens and powder-coated surfaces for medical molding. These features occur on flat and consistent surfaces of molded parts. Increase the mold temperatures: Cold mold walls prevent material flow. 07% can cause cosmetic problems on a part surface if the material is exposed to the temperatures of melt processing. 1. Splay is a term used in the manufacture of injection molded plastics to refer to off-colored streaking along the surface of a molded part. Gear to shape fittings comprises of a form and an injection molding press.