Tesis sobre el tema "Two component injection molding"

Das Fügen mehrerer Komponenten während des Spritzgießprozesses wird bei vielen Spritzgießsonderverfahren angewandt. Diese Arbeit beschäftigt sich mit der Verbundbildung zwischen einem kalten Einlegeteil und der einströmenden Kunststoffschmelze beim Spritzgießen, im Folgenden Stoffübertragung genannt. Ein Großteil der Untersuchungen findet an Zweikomponenten-Zugstäben statt, wobei erste und zweite Komponente aus dem gleichen Thermoplast gefertigt werden. Mögliche Einflussfaktoren auf die Verbundfestigkeit werden zunächst im Theorieteil vorgestellt und diskutiert. Eine Auswahl relevanter Prozess- und Materialparameter wird dann in praktischen Versuchen detailliert analysiert. Es wird nach korrelierenden Tendenzen sowohl zwischen unterschiedlichen Verfahren als auch zwischen verschiedenen Kunststoffen gesucht. Mittels statistischer Versuchsplanung werden die Spritzgießparameterkombinationen nach Größe des Einflusses auf die Verbundfestigkeit sortiert. Dies trägt zum Verständnis der bei der Stoffübertragung ablaufenden Grundmechanismen bei. Weiterhin werden die Einflüsse der Prozessparameter auf das neue Verfahren der In-Mold Oberflächenmodifizierung, bei dem ein funktionaler Modifikator während des Spritzgießprozesses übertragen wird, mit den Ergebnissen der Zweikomponenten-Verbundfestigkeit verglichen. Abschließend wird auf die Besonderheiten bei der selektiven Stoffübertragung eingegangen und das neue Verfahren des In-Mold Printing vorgestellt
The joining of two components by the process of injection molding is state of the art, although adhesion phenomena are not fully understood yet. The formation of bonds between a cold material, which was inserted or applied onto the surface of the cavity before injection molding, and an injected polymer melt is studied in this work. Providing sufficient bond strength, the material is transferred from the surface of the mold to the injection molded part. Possibly influencing factors on the bond strength are first identified, theoretically discussed, later in experiments varied and finally analyzed. Thereby correlating tendencies between different polymers and different in-mold technologies are observed. The relevant material and processing parameters are put in order by their influence on the bond strength using design of experiments. This helps to understand the mechanisms of the formation of bonds. The majority of the experiments is concerned with two component injection molding by measuring the bond strength of two component tensile bars, produced under varying processing conditions. In each case, first and second components are made of the same thermoplastic polymer. The thermal energy of the melt can be used also to initiate chemical reactions. This permits bonding of a thin layer of a functional polymer, which is applied onto the surface of the mold before injecting the melt, to the surface of the molded part. In this way, process-integrated surface modification during injection molding becomes possible. In a further attempt, patterns of paint are printed onto the surface of the mold by pad printing. During injection molding the paint is transferred completely to the surface of the polymeric part. Using this new technology of In-Mold Printing, fully finished surface decorated parts can be produced by injection molding

An experimental investigation has been carried out to study the heat transfer in a two-phase two-component mixture flowing upward inside a 1" double pipe heat exchanger. The heat transfer coefficient was measured using either air to lift the liquid (air-lift system) or a mechanical pump. The heat transfer coefficient results have been extensively studied and compared with other workers' results. An attempt was made to correlate the present heat transfer data in dimensionless correlations. Possible factors affecting the two-phase heat transfer coefficient have been studied with special attention being given to the fluid properties, particularly the liquid viscosity. Experiments were also carried out to investigate the effect of solid particles added to a liquid flow on the measured heat transfer coefficient. The present investigation was carried out using air as the gas-phase ranging from 2x 10-5 up to 80 x 10-5 m3/s. Liquids used were water and glycerol solutions with viscosity ranging from 0.75 up to 5.0 C. P. and flowrates between 4x 10-5 and 25 x 10-5 m3/s. Void fraction and pressure drop were also measured during the heat transfer process. Flow pattern in gas-liquid mixture was investigated in a perspex tube of identical dimensions to the heat exchanger tube.

Purpose: The purpose of the study is to identify, design and apply a method for operational production planning. The purpose of the method is that it takes into account the respective demand patterns of the articles, which determines the choice of calculation model and that the method also takes into account the production capacity limitation set. The result can be applied as a basis for decision-making for small and medium-sized manufacturing companies that are facing an expansion. Objective: The following research question was the main objective of this study.How would an appropriate operational planning method be shaped according to the specific characteristics of the products and their diverse demand patterns in small and medium-sized manufacturing companies with capacity limiters? Method: The study is a qualitative one-case study with quantitative elements. The empirical data used in the study was collected through unstructured and semi-structured interviews where the snowball effect has been applied and also observations have been performed. Results: The study has enabled a higher degree of utilization of the capacity limitation set, by developing standardized block sizes. The first step was to identify demand patterns into which the studied articles could be categorized. The demand pattern was applied in order to be able to apply the correct calculation model to the correct article. The calculation model was then standardized by applying PoT to be able to obtain standardized block sizes. The method was illustrated in a Gantt chart to demonstrate its usefulness.
Syfte: Studiens syfte är att identifiera, utforma och applicera en metod för operativ produktionsplanering. Ändamålet med metoden är att den tar hänsyn till artiklarnas respektive efterfrågemönster vilket avgör valet av beräkningsmodell samt att metoden tar även hänsyn till produktionens kapacitetsbegränsning ställare. Resultatet kan appliceras som beslutsunderlag för små samt medelstora tillverkande företag som står inför en expansion. Forskningsfråga: Följande forskningsfråga var objektet för denna studie. Hur skulle en lämplig operativ planering formas utefter artiklarnas specifika egenskaper och deras olikartade efterfrågemönster hos små och medelstora tillverkande företag med kapacitetsbegränsningen ställare? Metod: Studien är en kvalitativ en-fallstudie med kvantitativa inslag. Den empiriska data som använts i studie än insamlad genom ostrukturerade samt semistrukturerade intervjuer där snöbollseffekten tillämpats och även observationer har utförts. Resultat: Studien har möjliggjort en högre utnyttjandegrad av kapacitetsbegränsningen ställare, genom att framta standardiserade blockstorlekar. Första steget var att identifiera efterfrågemönster som de studerade artiklarna kunnat kategoriseras in i. Efterfrågemönstret har tillämpats för att kunna använda rätt beräkningsmodell på rätt artikel. Beräkningsmodellen standardiserades därefter genom tillämpning av PoT för att kunna erhålla standardiserade blockstorlekar. Metoden illustrerades i ett Gantt-schema för att påvisa dess användbarhet.

博士
中原大學
機械工程研究所
84
The purpose of this research is to conduct a preliminary sutdy concerning the characteristics of the post-filling process of two-component injection molding process, namely co-injection molding process and gas-assisted injection molding, in order to investigated the effect of processing and the design parameters on their molding processes and part quality. This research firstly focuses on the investigation of the progression for both skin and core melt fronts during the post-filling process. Experimental studies of polymer melt flow in the post-filling stage of co-injection molding process have been performed using the sequential injection of transparent and colored polystyrene resin. During the post-filling process, polymer melt flows significantly and the amount of melt flow increases with increasing packing pressure. Also, the polymer melt flow is more concentrated around the cavity location near the gate area and is less distinguished far away from the gate. A layer control volume/FEM and tripl-filling-parameter algorithm employed within each grid layer in the gapwise direction are applied to trace the melt fronts advancement for both skin and core materials during the post-filling process. Numerical simulation shows good consistency with experimental results in both skin and core material distributions. If the edge effect is taken into account using a shape factor as a geometric correction and melt frozen effect is considered, the simulation accuracy is further improved. Secondly, numerical simulations and experimental studies of gas penetration and melt flow are carried out during gas-assisted injection molding. Distribution of the skin melt thickness along gas penetration path is described as a simple model of two phase flow. A simple formulation based on non-isothermal power-law fluid model is derived in order to evaluate the effect of various processing parameters as well as melt rheological behavior on the skin melt formation. Skin melt thickness ratio

碩士
中原大學
機械工程研究所
97
Abstract Product design becomes more personalized as the time advanced, it should be designed pretty appearance by using various colors such as cell phones, electric watches etc. For the sake of it, we provide several varieties tooling designs in injection process; two-component tooling is widely used in the production by many injection factories now. In order to have more competitive advantages, the academy and industry are indulged in the researches of exact injection process in recent years. There are many different parameters related about fluidity of plastic-melted parts in each kind of injection process, such as pressure, temperature, time etc. Engineers should research the real parameters about the injection process by CAE moldflow analysis software to develop the fine goods rapidly. If so, the cost and time-elapsed will be dramatically reduced. This study is a research of the design for audio two-component plastic panel. Firstly, referring the two-component plastic product of audio two-component panel, we build and construct 3D designs by using computer-aided design software Pro/Engineer, then we construct mold flow analysis based on different controlled parameters. Secondly, referring the actual two-component plastic products of audio two-component panel, we choose the resin of Polycarbonate and Polycarbonate/ABS whose characteristics are good shock endurance, good transparency, high dimension stability after shaping, nonpoisonous property as our study object, then the optima parameters will be found by Taguchi method coordination and software of Moldflow in this study. The temperature of the first product of mold is suggested 100℃, the temperature of polymer melt is set by 320℃, the time of filling is 1.1 second. The temperature of the second product of mold is suggested 80℃, the temperature of polymer melt is set by 270℃, and the time of filling is 0.9 second. It is confirmed by checking examples of stereo faceplate with two-color injection method with the simulations from software, so the old try-and-error method could be replaced for the sake of profits and efficiency.

碩士
國立中興大學
機械工程學系所
98
Recent years, multi-color injection molding products are increasing quickly because of requirements from consumer market for product’s functionality and appearance. Consequently, the multi-component injection molding technology becomes an important research direction. One of the critical factors for deciding the quality of injection molding product is the dimensional precision requirement. Since the amount of warpage will affect the dimensional precision requirement. Therefore, this research is focus on the discussion of warpage of multi-component injection molding. The process studied in this research is to combine different plastic material by two-shot injection molding technology. One example is to combine crystallization plastic PP and elastomer TPE, and the other one is to combine amorphic substance plastic PS and the elastomer TPE. The analysis is done by using computer-aided engineering software Moldex. This study is divided into two directions. The first direction is using Taguchi method to analyze the control factors of mold designing parameters to find out the optimal parameters for the minimum amount of warpage. The result shows that the improvement can reach 91.8% for optimal combination of parameters of the first shot compared to the average amount of warpage. The optimal combination of parameters for the second shot also can improve the amount of warpage to 40% compared to the average amount of warpage. The second direction is again using Taguchi method to analyze the control factors of process parameters to find out the optimal parameters for the minimum amount of warpage. Result shows that increasing packing pressure, melt temperature, mold temperature and packing time are helpful for reducing amount of warpage.

碩士
龍華科技大學
機械工程系碩士班
103
With the continuous developing of modern plastic craft, many new macromolecule materials have been developed and, compare with the characteristics of wood and metal, new materials’ are regarded to have higher utilizability. Therefore, many new techniques of specific injection molding are created correspondingly. The most representative new technique is Multi-Component Injection Molding. The purpose of this research is to manufacture ABS+TPR and ABS+TPU, the sealing component of linear guide, by the technique of Multi-Component Injection Molding. In the manufacturing process of TPU and TPR, burr usually happened due to over-pressure and, if the pressure is insufficient or the time of pressure-keeping is too short, contraction is generated due to the flexibility. Furthermore, the connectivity of ABS+TPR and ABS+TPU could be influenced by different temperature of cement or that of die. The higher temperature, the better connectivity. Compare to TPR, TPU has better connectivity so that there is no need to add cement between TPU and ABS, the backing material. For TPR, pseudo-connect usually happened between TPR and ABS. Founded in the research of dustproof depended on mechanical characteristics, drag force would decrease to a specific range when the operation length gets a certain distance. It’s called natural wear period. The effect of dustproof gets worse when this period ends. In the next period called saturation period, the wood dust gets inside the carriage continuously until the operation stops. Based on the research data, the effect of dustproof component stays in optimum condition during the natural wear period and gets worse dramatically when the speed of wear decreases slowly.

碩士
國立高雄應用科技大學
模具系碩士在職專班
106
Car industry has grown vigorously for the past decade, leading to the increasing of vehicle numbers and drivers. Therefore, people pay more and more attention on driving safety system than before. High-Tech techniques are combined into active or passive safety equipment. Among them, parking sonar system is an important driving assistant equipment, for offering more comprehensive safety and convenience to car-driving. In fact, parking sonar system with complex design has several components. One of the important components is “Parking sonar sensor head cover”. It’s for fixing the sonar sensor onto bumper steadily and prevention of sensor falling off. Because head cover is installed at the outside of bumper, even after being wind-blown, sunshine-exposure, rain-spread, dust-dirt-grit-attacked, or shocked by high-pressured water gun when washing car, it still has to stay well-structured. As a result, head cover needs to contain precise scale and weatherability. Hence, this thesis focuses on commercializing new designed sensor cover. Firstly, we design and manufacture the sensor cover mold through mold-flow analysis. Secondly, produce sensor cover prototypes by injection molding with composite material of PBT mixing glass fiber, and investigate the key parameters of injection molding, which determine the forming precision and quality of head cover. Finally, analyze the root causes of cover defects when forming, review the countermeasures, and find the optimistic parameters to mass-produce parking sonar sensor head cover. Keywords：Parking sonar, Parking sonar sensor head cover, Injection Molding, PBT, Glass fiber.

碩士
中原大學
機械工程研究所
106
This study utilizes Design of Experiments methods to find more stable and suitable injection molding parameters. These results are imported from exper-iments designed to have all parameters covered and calculated to obtain a more adequate parameter set. This method helps to reduce trial shots and provide a stable production process, where the trial shots in real field application, can be very costly. Advance injection molding machine, auxiliary Coordinate Measurement Ma-chine (3D CMM) and Minitab software package are used to analyze experiment results, they can solve abnormal production and reduce cost by setting the production parameters to an optimal. This method reduces the sensitivity of parameters which reduces quality variance due to parameter variation. The main idea of this thesis is to obtain an optimal processing condition. From results of the trial experiments defined by the DOE method and put into Process Performance Index (PPI) calculation to generate a better molding parameter set for production process. It can ensure stable production process and uniform quality for components. The experimental process is not only to search root cause of component defect but also to provide long-term stable production conditions by statistical data. Medical equipment requires stable part quality, hence this method can help to stabilize the part quality greatly by finding an optimal processing condition set. As like that, all plastic injection-molding can use DOE to find the best param-eter for production processing too.

碩士
逢甲大學
材料與製造工程所
100
In this study, the focus is placed on the mold flow analysis with the control valve component of the pneumatic hand-held tools. It is made by inject PTU plastic into embedded POM of insert molding. Taguchi method was implemented in the design experiments with Moldex3D mold flow analysis software, to reducing the number of experiments systematically, and investigating the influences from various conditions on the insert deformation parameter to the injection molding. Therefore, to obtain the minimum volume on the variants to optimize the best injection molding process parameters. The results reveal that adjusting the temperature of plastic and filling time can effectively reduce the amount of deformation, in which the temperature of plastic is as of the most influential factor. The parameter of deformation amount from the original CAE analysis was 0.5719 mm, whereas the optimized parameters from the CAE analysis of the deformation is 0.4663 mm. Optimizing the process parameter has improved 15.63% considerably of the amount of deformation comparing to the original process parameters, which further proves that Taguchi method does facilitate and improve design experiment planning and parameter optimization significantly.

碩士
國立虎尾科技大學
機械與機電工程研究所
95
ABSTRACT Traditional three-platen injection molding machine usually had the following shortages: more complicated manufacturing technic of the parts, more space for storage, and more insufficient in function. For the sake of searching a more competitive new injection molding machine, this thesis is about developing the two-platen machine, with the advantages of keeping the general functions of three-platen machine, increasing other functions, lessening the machine space, and lower the manufacturing cost. The effects on developing the two-platen hydra-mech injection molding machine: 1. Clamping Unit: Lessening 30% space, reducing the cost, and increasing the competitiveness. 2. Injection Unit: With the design of cylindraceous structure, it is easier to be manufactured precisely. 3. Hydraulic Unit: Without any welding points of the hose and pipe. 4. Cover Unit: With the new enclosure design of the cover, it can avoid the vibration of the frame. 5. Machine base: The original structure is immovable. With the new assembling design, it can have many different collocations for choosing. Keywords : Injection molding machine、Two-Platen Hydra-Mech、Clamping、Injection、Oil-hydraulics

碩士
國立臺灣科技大學
機械工程系
101
This study predicts the two-dimensional fiber orientation in the injection molding process and to explore the influence of various parameters on the fiber orientation in the injection molding process. In this study melt flow inside the cavity is described by the continuity equation, momentum equations, energy equation and the front transport equation. The governing equations are discretized by a finite volume approach, while the volume of fluid method is employed to calculate the location of melt front. To describe the dependence of melt viscosity on temperature and shear rate the Cross-WLF model is adpoted in this study.The location of fiber at different time instance is first traced by a Lagrangian approach. The orientation of fiber is then calculated by solving the differential equation of the second-order tensor. A fifth-order Runge-Kutta method is used to solve the pathline and tensor problem.This study found that most of the fiber orientation tends to flow direction.In this study investigated the geometric shape of fiber orientation effect. To explore ten different shapes. To observe the different filling time of fiber orientation.

碩士
國立臺灣科技大學
機械工程系
102
This study focuses on the mold design using Moldex3D (True 3D CAE Analysis), focusing on the variables of materials viscosity properties (SABIC EXL4419 with 10% GF and SABIC D351 with 30% GF), part thickness (0.65mm and 0.5mm) and number of gate(gate Q’ty=2,4,6 set). The results of weld line, injecting pressure, velocity of melt near gates, melt temperature near gates, deformation of component are correlated with the mold design, using different optimal molding parameters. Results show that the number of gate and the viscosity properties of material play the crucial role on the success of molding a thin part. For a thickness of 0.65 mm, a larger number of gate caused a higher degree of deformation. On the other hand, for a thickness of 0.50 mm, a larger number of gate caused a lower degree of deformation. Such a difference arises from difficulty in molding a thinner part that the molding parameters change dramatically.

博士
國立清華大學
動力機械工程學系
94
The inkjet printing technology and injection molding technology have been widely explored by the electronic industry in developing new manufacture processes. To shorten the design cycle, the numerical simulation of two-phase flow is the required tool. The three-dimensional simulations of two-phase flow based on a numerical scheme comprised of a finite volume formulation for discretizing governing equations of the flow field and a volume-of-fluid method to predict the fluid interface are presented. Non-staggered grid system is used. An interpolation practice of second order accuracy is adopted to calculate the physical quantities at cell-face centers. The deferred correction approach is used to compute the convection and diffusion terms by blending the upwind and central difference scheme. An implicit three-time-level scheme with second-order accuracy is adopted. The SIMPLE algorithm is adopted to treat the velocity and pressure coupling. In the study of the two-phase flow on inkjet printing technology, the surface tension is calculated by a continuum surface force model. The contact angle between the fluid and the solid wall is explicitly enforced at the fluid interface. The numerical predictions of meniscus shape are similar to measurement results which published by other researchers. And then, micro flow visualization and computational results are complementarily presented of the extrusion, detachment, recoil, and free flight of the inkjet droplet column ejected from a commercial piezo-electrically driven inkjet printhead. Subsequently, the verified numerical code is applied to study the influences of surface tension, fluid viscosity, contact angle θs between the droplet and cavity walls and droplet impinging velocity on the deposition process of a microfabrication based on inkjet printing technique. The effects of the surface tension on the deposition process are examined by varying the drop’s surface tension, i.e. σ = 10 dyne s/cm, 28 dyne s/cm, 50 dyne s/cm and 70 dyne s/cm, while the viscosity of the droplet is fixed at μl = 5 cp. The effects of the viscosity on the deposition process are examined by varying the drop’s viscosity, i.e. μl = 2.5 cp, 5 cp and 10 cp, while the surface tension of the droplet is fixed at σ = 28 dyne s/cm. It is found that there exist a critical Reynolds number and a critical Weber number beyond and below which the ink droplet fails to form a layer, respectively. Furthermore, the hydrophilic effects are explored by choosing θs at 10°, 30°, 50°, 70°, 90°, and 120°, whereas the contact angle between the fluid and bottom wall is fixed at θb = 30°. The influences of droplet impinging velocity are examined by increasing its value from 1.0 m/s to 7.0 m/s identifications of a critical contact angle (θs)c, = 70o and a critical range of impact velocities, 5 m/s to 7 m/s. At these critical values the formation of an intact flat film in the cavity is fulfilled. In the study of the two phase flow on injection molding technology, the full Navier-Stokes equations are solved. The rheological property of polymer melt flows is calculated by the modified Cross-WLF model. The first case is the gas-assistant injection molding process of the rectangular plane with half cylinder. The predicted distributions of gas core thickness are compared with the corresponding experimental observation. In the other cases, several three-dimensional characteristics are demonstrated. The numerical results depict important three-dimensional phenomena, such as the jetting effect, race-tracking effect, corner effect, and the flow asymmetry after the gas is injected, which can not be described by any two-and-half dimensional model or Stokes-type three-dimensional methods commonly used in the current commercial CAE simulations for melt flows.

碩士
國立中央大學
機械工程研究所
87
Metal injection molding (MIM) is a method in metallurgy that combines the benefits from both plastic molding and powder molding. Its advantages include high capacity, high accuracy, low cost for mass production, capability in treating complicated shapes and insensitivity of material using. In the MIM production processes , debinding is the most important and time consuming one. Failing in this key process always leads to the overall failure of the MIM production. To analyze the global behavior of the two dimensional wick debinding, we apply porous media theories and the finite element technique combined with body-fitted grid generation method. The variables which include binder viscosity , the size of the powder , the permeability and prorsity , control the debinding velocity , debinding time and the transform of the binder front . Although quantitatively, the result of simulation still is a great different with the experiment , The some conclusion is got , like that the external of the binder in the wick materal is similar with the one of the compact ,and the debinding time is the proportion with the area of the circle and quadrate compact .

Das Fügen mehrerer Komponenten während des Spritzgießprozesses wird bei vielen Spritzgießsonderverfahren angewandt. Diese Arbeit beschäftigt sich mit der Verbundbildung zwischen einem kalten Einlegeteil und der einströmenden Kunststoffschmelze beim Spritzgießen, im Folgenden Stoffübertragung genannt. Ein Großteil der Untersuchungen findet an Zweikomponenten-Zugstäben statt, wobei erste und zweite Komponente aus dem gleichen Thermoplast gefertigt werden. Mögliche Einflussfaktoren auf die Verbundfestigkeit werden zunächst im Theorieteil vorgestellt und diskutiert. Eine Auswahl relevanter Prozess- und Materialparameter wird dann in praktischen Versuchen detailliert analysiert. Es wird nach korrelierenden Tendenzen sowohl zwischen unterschiedlichen Verfahren als auch zwischen verschiedenen Kunststoffen gesucht. Mittels statistischer Versuchsplanung werden die Spritzgießparameterkombinationen nach Größe des Einflusses auf die Verbundfestigkeit sortiert. Dies trägt zum Verständnis der bei der Stoffübertragung ablaufenden Grundmechanismen bei. Weiterhin werden die Einflüsse der Prozessparameter auf das neue Verfahren der In-Mold Oberflächenmodifizierung, bei dem ein funktionaler Modifikator während des Spritzgießprozesses übertragen wird, mit den Ergebnissen der Zweikomponenten-Verbundfestigkeit verglichen. Abschließend wird auf die Besonderheiten bei der selektiven Stoffübertragung eingegangen und das neue Verfahren des In-Mold Printing vorgestellt.
The joining of two components by the process of injection molding is state of the art, although adhesion phenomena are not fully understood yet. The formation of bonds between a cold material, which was inserted or applied onto the surface of the cavity before injection molding, and an injected polymer melt is studied in this work. Providing sufficient bond strength, the material is transferred from the surface of the mold to the injection molded part. Possibly influencing factors on the bond strength are first identified, theoretically discussed, later in experiments varied and finally analyzed. Thereby correlating tendencies between different polymers and different in-mold technologies are observed. The relevant material and processing parameters are put in order by their influence on the bond strength using design of experiments. This helps to understand the mechanisms of the formation of bonds. The majority of the experiments is concerned with two component injection molding by measuring the bond strength of two component tensile bars, produced under varying processing conditions. In each case, first and second components are made of the same thermoplastic polymer. The thermal energy of the melt can be used also to initiate chemical reactions. This permits bonding of a thin layer of a functional polymer, which is applied onto the surface of the mold before injecting the melt, to the surface of the molded part. In this way, process-integrated surface modification during injection molding becomes possible. In a further attempt, patterns of paint are printed onto the surface of the mold by pad printing. During injection molding the paint is transferred completely to the surface of the polymeric part. Using this new technology of In-Mold Printing, fully finished surface decorated parts can be produced by injection molding.

碩士
國立高雄科技大學
模具工程系
107
Liquid Silicone Rubber (LSR) is a thermosetting elastomer material, has a good sense of touch and does not cause harm to the human body. The general thermoplastic material has mechanical strength, and the combination of the two has excellent functional additivity. Such as electrical insulation, sealing, impermeability, shock absorption, heat resistance and mechanical strength, etc. Can be applied medical industry, diving equipment, automotive industry, has gradually become an indispensable material. In order to respond to demand, it is also a future trend to develop a two-shot injection molding of P+R in combination with the advantages of plastic (P) and rubber (R). Because LSR needs to be crosslinked and cured at high temperature, general temperature range 150~200°C,the mold temperature of general thermoplastic materials is usually between 50~120°C, therefore, the temperature control of the P+R two-component injection mold is extremely important, includ the cooling part of the thermoplastic material, the heating part of the thermosetting material, and the insulation of the mold and the injection machine table and the environment. This research develops a new mold of P+R two-component injection molding, use polyphenylene sulfide (PPS) and polycarbonate (PC) are used as thermoplastic materials, composite injection with the LSR in the same of two-component injection mold. At the mold design stage, mold flow analysis software (MOLDFLOW) and heat transfer analysis software (ANSYS) were used to analyze the plastic forming and heat transfer analysis of the mold to determine the design of the runner, cooling and heating system. After the mold is completed, the two-component injection molding is performed to verify the advantages and disadvantages of the heat insulation design and the feasibility of the two-component injection molding. The research results showed inner and outer sides of the mold male and female templates, and the heat shields between the two mold holes (thermoplastic and thermoset) can effectively isolate the heat transfer at different temperatures of the two mold cavities, and can prevent the temperature from being transmitted to the injection machine to maintain the cavity temperature. Uniformity, increasing the cross-linking cure rate of LSR. The thermoplastic material (semi-finished product) is transferred into the thermosetting cavity after forming, and its dimensional shrinkage and temperature have a great influence on the filling and forming of the LSR, which is the key to the technology of the two-component injection molding.

Dissertação de mestrado integrado em Engenharia de Polímeros
O mercado automóvel é um grande consumidor de peças plásticas, nomeadamente de peças injetadas, sendo por isso, um mercado que se encontra sob rigorosa regulamentação e requisitos bastante apertados que as peças necessitam de cumprir. É uma industria altamente competitiva e exigente, sendo necessária uma constante introdução de melhorias e inovação nos produtos bem como nos processos produtivos, possibilitando às empresas uma maior competitividade no mercado. O projeto a desenvolver centra-se na área de injeção de plásticos na empresa Aptiv, em Braga, no âmbito da dissertação do Mestrado Integrado em Engenharia de Polímeros. É essencial a produção de produtos de qualidade e sem qualquer tipo de defeitos, para isso é necessário existir um controlo de qualidade das peças injetadas muito rigoroso. O trabalho desenvolvido na dissertação baseia-se na identificação e respetiva resolução dos defeitos da injeção, tendo em conta os parâmetros da máquina e a influência que estes podem ter ou não durante o processo de produção do produto. Torna-se obrigatório fazer um estudo dos defeitos durante o processo de injeção e compreender onde estes podem ter origem. A primeira etapa do processo consiste em aprofundar os conhecimentos na área da moldação por injeção, perceber o modo como a peça em estudo é injetada. É necessário o estudo de todas as variáveis que poderão afetar o processo, matéria prima, periféricos usados e ambiente envolvente. Em seguida o objetivo é identificar os defeitos e verificar a frequência com que cada um aparece. Após esta analise as peças são submetidas a observação através de microscópio, análise da humidade do material e de microscopia Raman. Com estes testes, pode-se tirar conclusões dos defeitos a ser estudados Neste caso, verifica-se que os defeitos mais frequentes são os raiados, pontos pretos e pontos brilhantes. Com base no teste de microscopia Raman efetuado verifica-se que os pontos pretos é material policarbonato (PC) carbonizado, que os pontos brilhantes e os raiados é material policarbonato (PC). Posteriormente, faz-se o estudo dos parâmetros da máquina, através do método PCA, Análise de Componentes Principais . Este método permite verificar se existe alguma relação entre os defeitos encontrados e os parâmetros do processo de injeção. Após esta análise, conclui-se que os parâmetros do processo de injeção não são a causa do aparecimento dos defeitos.
The car market is a major consumer of plastic parts, namely injected parts, and therefore, a market that is under strict regulation and tight requirements that the parts need to comply. It is a highly competitive and demanding industry, requiring a constant introduction of improvements and innovation in products as well as in production processes, enabling companies to become more competitive in the market. The project to be developed focuses on the area of plastic injection in the company Aptiv, in Braga, within the scope of the dissertation of the Integrated Master in Polymer Engineering. It is essential to produce quality products without any kind of defects, for this it is necessary to have a very strict quality control of the injected parts. The work developed in the dissertation is based on the identification and respective resolution of the defects of the injection, taking into account the parameters of the machine and the influence they may or may not have during the production process of the product. It is mandatory to make a study of the defects during the injection process and to understand where they may originate. The first step in the process is to deepen the knowledge in the area of injection molding, to understand how the part under study is injected. It is necessary to study all the variables that may affect the process, raw material, used peripherals and surrounding environment. Then the goal is to identify the defects and check how often each one appears. After this analysis the pieces are submitted to observation through a microscope, analysis of the humidity of the material and Raman microscopy. With these tests, one can draw conclusions of the defects to be studied. In this case, it is verified that the most frequent defects are rays, black spots and bright spots. Based on the Raman microscopy test carried out it is verified that the black dots are carbonized polycarbonate (PC) material, which bright and light dots are polycarbonate (PC) material. Afterwards, the machine parameters are analyzed through the PCA method, Principal Components Analysis. This method allows to verify if there is any relation between the defects found and the parameters of the injection process. After this analysis, it is concluded that the parameters of the injection process are not the cause of the appearance of the defects.