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. The injection pressure is too lowEffect of the processing conditions on the variations of the bulk temperature, T b , at the end of mold filling at the two locations: in (left) and away (right) from the weld-line (T w , T inj. On the other hand, the mechanical strength at the weld line area of an injection molding part is always a concern. Redesign the mold to prevent the weld line. 2. 18 ชิ้นงานเกิดเป็นเส้นรอยประสาน Weld line. industry, to deliver intuitive injection mold-ing simulations embedded in NX. This weld line can act as a weak spot in the material. This will produce parts with aExperimental results show that the weld-line strength from a standard test is not applicable in microinjection molding. Here is a look at the differences between them, the causes of meld and knit line imperfections, and their impact on part durability. warpage, and weld line. th INTRODUCTION Injection molding is one of the most Weld lines are a common defect generated in injection molding, which apparently affects the performance of final products, but the available reports on carbon fiber-reinforced thermoplastics are still rather few. The second technique, cascade injection moulding, can produce parts free from weld lines. Google Scholar | Crossref | ISI. The weld line is then created with a higher flow front temperature and is packed with more pressure. Mobile 0813; Shinko Sellbic Co. The following are the reasons. 3 Materials Polypropylene (PP) and. The. In this regard, Taguchi orthogonal experimental design is adopted, and five processing parameters, the mold temperature, melt temperature, cooling time, packing. , Ziegmann G. Known also as knit lines and weld marks, weld lines are difficult to eliminate completely, especially if your injection molded part requires holes. 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. Plastic part design for injection molding – An introduction. • Optimize the design of the runner system. 010 0. Weld line strength is important in blow molding as well as injection molding. Int J Adv Manuf Technol 52:131–141. (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. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. Sink Marks Cause 2: Low Pack and Hold time. The terahertz time-domain spectroscopy (THz-TDS) imaging technique was used to detect the weld line defect of an injection-moulded short glass fiber-reinforced composite. Five injection molding process parameters, including mold temperature, melt temperature, packing pressure, injection. These master batches and PP pellets were dry-blended by adjusting the ratio such that the fiber contents were 10, 20, and 30 wt%. Weld lines can be caused by material flowing around holes or inserts in the part, multiple injection gates or variable wall thickness where hesitation or "race tracking" can occur. Weld lines can appear on the components when the molten plastics meet each other as they are flowing from two different parts of the mold. Polymers 2023, 15, 2440 3 of 21. This may require higher melt temperature or lower injection speed . This can allow the. A weld line refers to a line, notch or color change that is created on the molded part caused by the convergence of two separate flows of molten plastic. The weld-lines are undesirable from both aesthetic and functional points of view and their effect is different for varied materials, process conditions, loadings, forms. Weld lines in injection molding are a type of cosmetic defect that detracts from a plastic part’s appearance. Mold. Make the size of runner channel wider and/or shorter. Fracture Toughness of Weld Lines in Thermoplastic Injection Molding, Polymer Engineering and Science, 33(15): 996-1001. In narrow fields, a limited amount of molten liquid can solidify and block the flow. ac. 0 mm, is designed to conduct the. Lugs size is 65 х 24 х 4 mm. Weld lines not only affect the appearance and quality of products, but also cause negative influences on the mechanical properties. com1. Weld lines have been one of the common defects puzzling the injection molding industry. In this way critical areas of the interface in regard to the lack of interdiffusion and the inappropriate molecular orientation were found to be placed near. This article will introduce you the usage, types, and advantages of the Sequence Injection Timer. 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. A flow mark is commonly referred to as a flow line occurs during the process of injection molding. 2. These are caused by the shot of molten plastic moving at different speeds throughout the injection. A weld line occurs when two or more molten plastic flows meet and fuse during the injection molding process, resulting in a visible line on the surface of the molded part. For multiple gate and complex part, molding weld-lines are unavoidable, therefore mechanical behavior of the weld-line needs to be predicted. (2) Causes & Countermeasures (See the table below) *Note: Flash also tends to occur when the injection pressure/speed are too high, but molding time is too long and mold temperature is too low. 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 diameter of the hole is 12 mm. In the present study, Moldflow® software is applied to simulate the injection molding of automobile instrument light guide bracket and optimize the injection gate position. The weld lines in injection molded parts arise as a result of the collision of two fronts of the flowing material, which fills the mold cavity and are sometimes unavoidable [1][2][3] [4]. Key words: weld line strength, thermoplastic composites, injection molding, wall thickness, skin and core layers Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand. 4. Thus, it is important to understand (i). (2) Adjust the injection speed: high speed allows the melt to reach the confluence without cooling down, and low speed allows time for the air in the cavity to be discharged. 6. The Factors that Cause Weld Line in Injection molding Pressure. In this study, the effects of injection temperature, injection pressure, and fiber cont. Injection Molding Glossary; Weld Lines; Weld Lines. Injection molding could be applied with many polymer materials, such as. Introduction. Weld line additionally called as knit line, is a defect that occurs when the injected plastic meets within a. The utility model relates to a mold structure capable of eliminating the appearance of weld lines of a hole. A weld line is often unavoidable. In this study, polypropylene (PP) was compounded respectively with carbon nano fibers (CNFs) and TiO 2 nano particles at various weight fractions (10, 20, 30, 35. Weld lines, knit lines, and meld lines are terminologies to describe the imperfections of finished parts in plastic injection molding processing. Fisa et al. This gives a clue as to how it was formed. Unless you are manufacturing an extremely simple part with one gate and a unidirectional flow front, your part will have weld lines. Flow lines are off-color lines, streaks, and other patterns that appear on the surface of a part. These lines usually occur around holes or obstructions and cause locally weak areas in the molded part. Figure 2. They are the result of fundamental physical effects taking place inside of the mold tool cavity. The microstructure of weld lines is clearly observed from the micrographs. Weld line reduction is one of the major concerns in plastic injection molding (PIM) that results in high surface appearance and high strength of a plastic product. Remember, by avoiding weld lines, you can lessen operations cost. This method was adopted. In an injection molding process, a weld-line forms when two flow fronts meet each other. Flow front tracing simulation results for weld line developing process in micro injection molding with Comsol ® Multiphysics 3. Bubbles are caused by melting flow fronts colliding in a mold cavity. This customary mark is caused by differential rates of cooling in the resin where. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. Xie L. A weld line can also be called a knit line. Weld lines are injection molding defects that can be mitigated by a number of tactics that depend on your part design. 000 0. In this study, we apply the technique of SAW to explore the acoustic properties near injection-weld lines by comparing the velocity of. Email him at jhenz@polymer-center. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. 2007; Lotti et al. open access Abstract Micro weld lines are the common problem that occurs for plastic molded parts through injection molding process. In the sense that the weld line is better formed before the resin temperature. Injection molding is nothing without molds. A weld line can appear during the absence of enough pressure to push the plastic flow and then meld. A weld line region is typically filled at the end of an injection stroke or during the pressure phase. when two or more melt flow fronts contact each other immediately after the cooling process. Weld lines are the result of fundamental physical effects taking place inside of the mold tool cavity, they are common imperfection to be found in most plastic injection molded parts. Therefore, it is recommended to do a moldflow study prior to the mold being built. 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. poor flow fronts that are too cold, this can also lead to a deterioration in the mechanical properties. Figure 2. Flow analysis of the weld line formation during injection mold filling of thermoplastics. 2(a, b). Figure 1. Let’s review what causes meld and knit line imperfections, how they’re different, and how they affect part durability. Micro injection molded polymeric parts coated with functional thin films/layers show off the promising applications in microsystems area. Another relevant topic in injection molding is the presence of weld lines (WLs) and their properties, which could lead to part weakness through surface disturbances, optical issues and reduced bonding [21, 22]. Try to gradually raise the mold temperature and barrel temperature. of micro injection molding process simulation by technology update and progress. 1. Xie L, Ziegmann G (2008) A visual mold with variotherm system for weld line studying micro injection molding. These flow fronts occur when the molten plastic material encounters obstacles, such as inserts, ribs, or other features within the mold cavity. , a post that forms a hole) and then rejoins, or when polymer melt fronts meet, from multiple injection points. At a low volumetric injection flow rate of 33. 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. 2. Meld and knit lines are actually both different types of weld lines. Try to gradually raise the mold temperature and barrel temperature. Weld lines, generated during injection molding, can significantly reduce the mechanical performance of structures. They happen when two flow fronts of melted plastic meet and solidify, leaving a visible line on the surface of the part. Here are some strategies. The weld line’s strength is reduced when. This gives a clue as to. 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). Article Google Scholar Deng YM, Zheng D, Lu XJ (2008) Injection moulding optimization of multi-class design variables using a PSO algorithm. The defects encountered could be caused by mechanical factors, such as poor mold design and mold manufacturing, or by processing related factors, such as incomplete kneading, inadequate molding pressure, injection. Weld lines represent the region where two separated melt fronts recombine. 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. Weld-line is a defect that arises in injection molding when two or more flow fronts collide. This is expected to achieve maximum results while the pressure holding effect will also increase. Computer simulation packages of injection molding have had success in predicting filling behavior in extremely complicated geometries, capable of predicting weld lines’ location exactly. Unfortunately, the 3D layering process creates ‘weld lines’ (an injection molding term) between layers which is essentially two layers of polymer that meet. 22 shows how the weld lines are formed when the melt splits around core pins during the injection molding process. 2-1. This failure causes the product to be damaged during use. Again, consult with professionals as to how you could improve mold designs. As such, optimizing mold designs should always be incorporated in your production model. When an external load is applied to a weld line region, the part’s potential for mechanical failure is increased. Poor weld line Ⅰ. Silver Streak. 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. 1. The melt stream is separated at the part’s cutout and reunited at the other end of the cutout. A poor knit line. Although they often cannot be avoided it’s possible to minimize their cosmetic effects to an acceptable degree through careful product design and. These lines can occur due to variations in wall thickness, gate location, or the geometry of the part. 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. 10 in Nguyen-Chung et al. It is not always easy to completely eliminate weld lines by simply adjusting the relevant injection mold design or the molding conditions. An evaluation model based on artificial neural network method. If weld lines are unavoidable due to multiple gates in a moulding, they should be positioned in the non-critical region. Procedia Mater Sci 2014; 3: 2048–2053. Causes: Weld lines are caused by the inadequate bonding of two or more flow fronts when there is partial solidification of the molten plastic. Characteristic: Basically, there are PA6 AND PA66(Nylon 6 or Nylon 66), Nylon has tenacious and wearable, self-lubricious and smooth characteristics with non-toxic and antibiosis and high water absorbability. [ 18 - 21 ] In addition, the effects of flow behavior of the polymer melt due to the optimal process parameters for the minimization of weld-line effects are an important consideration. 1% higher than the ones without ultrasonic assistant, which indicates that the weld line strength in micro injection molding can be well reinforced by the ultrasonic oscillation due to the fact that ultrasonic oscillation induces better diffusion among the melting. Abstract and Figures. The parts are molded flat and are slightly stressed once installed in an arced position, but not excessively. + Increase mold temp, or materials’ temp, or holding pressure. To prevent weld lines, increase the pressure and temperature. The weld-lines are undesirable from both aesthetic and functional points of view and their effect is different for varied materials, process conditions, loadings, forms. The thermo-rheological findings were used to investigate the sources of weld line weakness. If the plasticizing ability of the plastics injection molding machine is insufficient, the plastic. This type of injection molding resolves any trouble caused by undesired welding lines. Crack growth behavior. Weld lines not only affect the appearance and quality of products, but also cause negative influences on the mechanical properties. Improper fusion of two fluid flows, a state before weld line. Weld lines can compromise the strength and aesthetics of the part, so it’s important to carefully design the mold and. 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. Why You Should Avoid Weld Lines. Compd. Many works deal with weld lines and their dependence on processing parameters for conventional injection molding, but only a few works focus on the weld line in µIM. Increase the mold temperature. In the case of PC, the model predicts satisfactorily the weld-line strength as a function of injection temperature. In an injection molding process, a weld-line forms when two flow fronts meet each other. This consequently produces weld lines. In order to study the weld line developing process and its influence on mechanical properties in micro injection molding, a visual mold with variotherm system mold was designed and fabricated. Wu CH, Liang WJ (2005) Effects of geometry and injection-molding parameters on weld-line strength. poor flow fronts that are too cold, this can also lead to a deterioration in the mechanical properties. Weld lines create visible marks, but this type of injection molding defect can also reduce a part’s strength and durability. A tensile test specimen mold, which allows cavity thickness varying from 2. . Weld-line, a common occurrence in plastic injection moulding, is a representative defect compromising mechanical qualities and product appearance [16]. 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. Weld line strength vs. As a defect of micro injection molding parts, weld line is unfavorable since it will influence the surface quality and mechanical properties of micro parts. สาเหตุรองของการเกิดปัญหาการเกิดประกายเงิน (silver streak) 1. Effect of process parameters on the relative weld line strength From injection molding practice and literature, 1, 3,4 it is generally accepted that: if a weld line forms before the filling is. Change the gate locations. (1983). 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. 2. Effects of mold temperature and pressure on shrinkage 0. 7 in Kobayashi et al. Increase the injection speed to reduce the amount of cooling happening in the mold. Weld lines are a kind of Achilles heel of plastics. weld lines in infill analysis of injection molding simulation was observed [5]. The weld line in an injection molding product can significantly impact the strength and durability of the last part [12] [13][14][15]. Meld Lines. Sink Marks Cause 1: Incorrect Melt Temperature. Known also as knit lines and. Change the gate locations. Thus, it is important to understand (i) if the melt is able to fill the cavity up to the weld line location, (ii) where the weld line forms, and (iii) if the weld line is a cold or flowing one. Weld Lines. วัตถุดิบ พลาสติก PMPA ( อะคริลิก ) เกรด A. This study presents an innovative approach to enhancing weld line strength in advanced polymer injection molding through applying gas-assisted mold. Fracture behavior of weld lines in injection molded components loaded under real operating conditions. Moldflow is computer software that is widely used across the plastic injection molding industry to predict and optimize the injection molding process and assist with mold design. 1. * Corresponding author, e-mail: [email protected] an injection molding process, a weld-line forms when two flow fronts meet each other. 2021年4月23日 / by admin. JENIS-JENIS DEFECT (CACAT) PADA PRODUK INJECTION MOLDING PT. – Use generous and even. Weld or Knit lines are a plane or section in an injection molding part where the flow of molten plastics meets from different directions. Consequently, weld regions have been observed to have inferior mechanical properties compared to the bulk. 48 applied high-frequency induction heating to eliminate weld lines in an injection-molded plastic part, and experimental observation indicated that weld depth was reduced from 2. Meld lines are formed when two separate flow fronts meets. T he decreased gloss level at the position of. This injection molding defect appears as a black discoloration on the surface of the molded part. Flow lines arise when at least two melt fronts meet at an acute an-Weld line is aesthetically unpleasant and affects the mechanical strength of injection molded parts. 3. Weld line is formed when two different melt flows converge, as illustrated in Fig. 1. An injection molding gate is a critical component in mold design, acting as the passage through which molten plastic travels from the runners into the mold cavity. Weld lines can be caused by several different problems: Low temperature of injection moulding machine barrel. Shaofei Jiang. The effects of fiber concentration has been studied in detail. Miron MC, Major Z, Adachi T. Processing OptimizationReduced frozen skin thickness: High injection speeds also contribute to a thinner frozen skin at the weld line. <Materials> Pre-dry thoroughly. 015 0. In this paper, two different injection molding tests were completed. C. In a meld line, the plastic comes together at an angle greater than 135 degrees. Wavy lines are another feature of weld lines. Strength measurements should be made to. They. The impact behavior of weld-lines in injection molding. Weld lines are formed when two melt fronts come in contact with each other. 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. Multi-Shot Molding – A molding process that uses two or more plastic materials to form a single part. They are unavoidable even for moderate complex products. If it only affects the appearance, it can change the position of the burn four to change the position of the weld line. Meld and knit lines are actually both different types of weld lines. ”Weld Lines in a plastic cover. Weld lines, also known as knit lines, are a common defect in injection molding where two or more flow fronts of molten plastic meet but don’t properly fuse together. Re-balancing entire manufacturing lines may be required to effectively deliver and sustain SMED excellence. Weld line existence reduces the material strength; however, its demerit characteristics. In this study, we apply the technique of SAW to explore the acoustic properties near injection-weld lines by comparing the velocity of. Weld line and warping are two critical defects for injection-moulded part. It is important to investigate the weld line because the weld line area can induce potential failure of structural application. Adjust Injection Molding Parameters: Optimizing injection speed, pressure, and temperature can help ensure better melt flow and reduce the likelihood of weld line formation. Meld and knit lines are actually both different types of weld lines. The Problems & Solutions course is designed to train injection molding personnel in. The following are the conclusion drawn from the present research: 1. 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,. In this regard, the plasticizing ability of the plastic injection moulding machine should be checked. Abstract. 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. It has larger cross-sectional regions that allow sufficient molten plastic flow into the cavity. 1. This remains as a challenge for control engineers. 4 at different time steps (legend scale is volume fraction of. 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. Effects of fillers and/or reinforcements on weld-line strength of nylon 6/6. Polym Eng Sci 45(7. These lines can occur at the gate location, where the plastic enters the mold, or anywhere along the flow path. ” Weld Lines in a plastic cover. A weld line is a mark left on the surface of a plastic injected molded part. <Mold> Increase (or decrease) the size of the runners and gates. Weld line. 015 0. Some of the approaches include the application of machine learning methods (Chen 2008; Manjunath and Krishna 2012; Kuo et al. , Ltd. If the different flow fronts have cooled. 3. Gambar 2. Weld line problem which occurs in polymer parts produced by plastic injection method and affects appearance and strength on a large scale was researched in this paper. Insufficient plasticizing ability of injection molding machine. In this case the two flow fronts will meet and there will be very little molecular orientation across the weld. The main runner and sub-runner are too thin or too long. Flashes, 3. Ideally, the resin flow will split into two flow fronts to pass around the obstruction and then recombine into a single flow front. Various measures are taken at production sites to address these problems. In. 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. We investigate the effects of various heating times and. The injection molding process can be optimized to maximize weld line strength by increasing. 6. ResourcesTo study the weld line formation of colliding flow fronts the filling of a mold cavity was simulated. To respond to poor plasticization and uneven melt temperature, the molding cycle can be extended to make. Plastic Injection Molding Process. Fracture behavior of weld lines in injection molded components loaded under real operating conditions. Weld-line is a weak area which reduces the strength of the part locally. A flat product case was considered as an example of a typical aircraft structural element. Plast. [ 18 - 21 ] In addition, the effects of flow behavior of the polymer melt due to the optimal process parameters for the minimization of weld-line effects are an important consideration. Berikut beberapa di antaranya: 1. And how to use the 3 modes of the sequential controller correctly to prevent burn marks, weld line, short shot, and other part defects in injection molding. Consultant @ Effinno Technologies, BSME, MBA - Bridge between Plastics Injection Molding Knowledge and Practice. One of the things that can compromise an injection molded part is a weld line, also called a knit line. Its appearance can be improved by adjusting parameters. The molded plastic part may also appear to be rust-colored. In addition a weld line can be moved to an area where it is less visible. J. Weld Lines. Injection molding is a highly versatile manufacturing process used to produce a wide range of plastic products with precision and efficiency. This model provides the necessary information. When two or more strands of molten plastics meet in the mold, a weld line will be produced at the junction [1,2]. Install an ultrared light inside the hopper. They decrease the. The weld lines in blow molding occur wherever the pari son knits together in the head, mold tacking areas and mold parting pinch-off region. A weld line is a visible seam where two areas of the molten plastic meet. 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]. and most commonly, thermoplastic polymers are used. Threadline gap in-between part due to improper gate location in complex design parts including excess of holes (multipoint. The type of resin used during injection molding plays a large role in whether or not a knit line will be present. The weld-lines are undesirable from both aesthetic and functional points of view and their effect is different for varied materials, process conditions, loadings, forms of weld-line, etc. of micro injection molding process simulation by technology update and progress. Wu CY, Ku CC, Pai HY (2011) Injection molding optimization with weld line design constraint using distributed multi-population genetic algorithm. For multiple gate and complex part. Flow marks in injection molding can be avoided if adequate measures are taken. During the plastic injection molding process, one of the biggest challenges is. From Understanding Weld-line Integrity by Sabic Innovative Plastics, p. + Move gate (to where it is not visible). ABS is a commonly used plastic in injection molding due to its excellent mechanical properties and chemical resistance. To resolve this issue, rapid heat cycle molding (RHCM) has attracted attention as an innovative PIM technology. A weld line refers to a line, notch or color change that is created on the molded part caused by the convergence of two separate flows of molten plastic. As the unfavorable defect in micro injection molding parts, weld line brings reduced mechanical and physical properties, especially for nano filled composites. Weld Line defect analysis, the most common of many defects in injection moulding products. 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. Designers can easily set up and perform analysis with only a few clicks. Meddad and Fisa [3] found that the weld line is a zone between 2 and 8 mm wide extending throughout the thickness in which the fibers are oriented almost. That’s the air escaping out of the nozzle until the hose is full of pressurized water. It is possible to pre. [8,9] It is capable of. Adjust the design for the flow pattern to be a single source flow. Weld line location. The weld line in injection molding is created when two melt streams connect, as shown in Figure 1. M. It is important to investigate the weld line because the weld line area can. Weld lines occur when melt flow fronts meet during the injection molding of plastic parts. Weld lines can. The weld lines in injection moulded parts arise as a result of the collision of two fronts of the flowing material, which fills the mould cavity and are sometimes unavoidable. In addition, its tensile strength and stiffness will be sharply decreased. For thick-walled parts, slow injection rates result in more uniform polymer distribution . They. Published 5 July 2019. Valve gates also make weld lines less of. 2. Weld lines occur when melt flow fronts meet during the injection molding of plastic parts. ). 2. 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. Micro-injection molding (µIM) is a widespread process for the production of plastic parts with at least one dimension, or feature, in the microscale (conventionally below 500 µm). (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.