MXPA00007882A - Automated molding technology for thermoplastic injection molding - Google Patents

Abstract

A method for the automated optimization of an injection molding machine set-up process comprising injection molding one or more parts, inspecting the parts for defects, adjusting the injection stroke and/or the injection velocity and repeating the process until the defects are reduced. There is also disclosed a method comprising injection molding one or more parts, determining a mean injection pressure profile by measuring the injection pressure with the machine configured with a constant, desired injection velocity. Then the velocity profile is adjusted to reduce differences between the measured pressure and the mean pressure profile. A further method is disclosed wherein the kickback is calculated and adjusted from screw displacement, packing/holding time and pressure. Also disclosed is a method comprising injection molding one or more parts then determining the gate freeze time by incrementing the holding time and measuring the screw displacement.

Description

AUTOMATED MOLDING TECHNOLOGY FOR MOLDING BY INJECTION OF THERMOPLASTIC MATERIALS Field of the Invention The present invention relates to the injection molding of thermoplastic materials and in particular to the automation of the paper of the matrix or die adjustor in adjusting the parameters of injection molding machines. The invention is also applicable to the injection molding of reactive materials.

Background of the Invention Injection molding is one of the most important and efficient manufacturing techniques for polymeric materials, with the ability to mass-produce high-value-added products, such as compact discs. Injection molding can be used to mold other materials, such as thermosetting plastics, ceramic materials and metal powders. The process in its present form was developed in the mid-1950s, when the first reciprocating screw machines came to R? F.122421 to be available. The variations of the material, the machine and the process are important in this process of multiple variables, complex. There are three interaction domains for search and development: 1) polymer material technology: the introduction of new and improved materials; 2) the technology of the machines: the development of the capacity of the machine; and 3) processing technology: the analysis of the complex interactions of the parameters of the machine and the process. As improved product quality and improved engineering properties of polymeric materials are required, the injection molding process has become increasingly complex: because the properties of the service increase the processability of the material tends to be reduced. Thermoplastic materials can be classified as bulky or engineering materials. Engineering materials are typically more difficult to process, and more expensive, and therefore their processing could benefit most automated molding optimizations (AMO). Injection molding is a batch operation, so that the equipment of the machine ultimately affects productivity.

Any molding operation must aim to manufacture component products at a specific quality level, in the shortest time, in a repeatable and fully automatic cycle. The injection molding machines usually provide speed control and pressure control, that is, control the speed of the injection screws when filling the part and controlling the pressure exerted by the injection screw when the part is packed / retained, respectively. The following description involves the use of a modern injection molding machine, after about the 1980s, with the control of the speed of the mold filling and the control of the pressure of the packing / holding stages. The typical injection molding cycle is as follows: 1) Plasticizing stage: the plasticizing occurs when the screw rotates, the pressure develops against the "fully closed" nozzle and the screw moves backwards ("oscillates") to accumulate a weight of material introduced into the mold, fresh (the molten polymer on the front of the screw), ready for injection of the molten material at the front of the screw tip. The back pressure determines the amount of work performed on the molten polymer during the plasticization. The molten polymer is forced through the non-return valve of the screw. The material is fed to the screw by gravity from the cooper. The polymeric material may require conditioning, especially in the case of engineered thermoplastic materials, to ensure the homogeneity of the molten material and therefore that the molten material has consistent flow characteristics. 2) Injection / Filling Stage: the empty mold is closed, and a weight of material introduced into the mold, of the molten material, is ready in the injection unit, in front of the screw. When the injection / filling occurs, the molten polymer is forced through the nozzle, the cavities or runners, the gate and into the mold cavity. The non-return valve of the screw closes and prevents the counterflow of the polymer melt material. For this, the mold filling part of the injection molding cycle, high pressures in the order of 100 MPa are frequently required to achieve the required injection speed. 3) Packing / Compression Stage: a packing pressure occurs at a specified VP or "switching or changing" point. This is the point of transfer of the control of the speed to the control of the pressure, that is to say, the point in which the machine for the moldeo by injection changes or commutes from the control of the speed until the control of the pressure. The "switching or changing" should preferably occur when the mold cavity is almost full, to promote efficient packing. Switching or changing from injection to packing is typically initiated by the position of the screw. The commutation or change can be initiated by the pressure, i.e., the injection pressures of the molten nozzle material, hydraulic, or the parameters of the melt pressure of the cavity measured from the machine. The end of this stage is referred to as "packing time" or "packing time". 4) Retention Stage: a second stage pressure occurs after the initial packing pressure and is necessary during the initial stages of the cooling of the molded part to counteract the contraction of the polymer. It is required until the mold gate cools or freezes; the injection pressure can then be released. This phase compensates for material shrinkage, forcing more material into the mold. Typical industrial machine settings utilize secondary pressure, combining the packing and clamping phases, to allow for easier machine equipment. It has been shown that underpacking leads to premature shrinkage, which can lead to dimensional variation and sink marks. Overpacking can cause premature opening of the tool (ie, the die or mold of the component (s) to be manufactured) in a phenomenon known as burr formation, difficulties in the removal of the part (sticking) and excessive residual stresses that lead to cambering. The analysis of the packaging phase is an essential step, therefore, in the prediction of the quality of the final product. The filler portion after commutation or change may be more important than the speed controlled primary injection stage. The end of this stage is known as "retention time" or "holding time". 5) Cooling Stage: This stage starts as soon as the molten polymeric material is injected into the cavity. The molten polymeric material begins to solidify when in contact with the surface of the cavity. The estimation of the cooling time becomes increasingly important, especially when large numbers of components are being molded. To calculate the cooling time, the expulsion temperature of the component must be known. Cooling an injection molded product evenly can mean cooling the mold at different speeds, in different areas. The goal is to cool the product as quickly as possible, while ensuring that faults such as a poor appearance of the surface and changes in physical properties are not found. The objectives of a cooling system are: (i) minimum cooling time, (ii) cooling even on partial surfaces, and (iii) balanced cooling between a core and a part of the cavity of a two-plate tool system. The temperature control of the tool is required to maintain a difference of the temperature AT between the tool and the polymeric melted material. For example, a temperature of the typical polyoxymethylene melt material is 215 ° C, the temperature of the tool is 70 ° C, and therefore AT = 145 ° C. Adverse effects for product quality should be expected due to poor control or no temperature control. The cooling phase makes it possible for the polymer melt to solidify in the print, due to the transfer of heat from the molded product to cool. The temperature of the tool influences the speed at which heat is transferred from the polymer melt material to the tool. Differences in the heat transfer rate influence the shrinkage of the polymer melt, which in turn affects the It has an influence on the density of the product. This effect influences the weight of the product, the dimensions, the microstructure and the surface finish. The surface temperature of the tool cavity is critical to the processing and quality of the injection molded components. Each part of the product must be cooled at the same speed, which often means that uneven cooling must be applied to the tool. Therefore, for example, the cooling water must be fed to the internal parts of the cooling system of the tool (particularly in the area of the gate) and the warmer water must be fed to the external parts. This technique is essential when flat components are cast to narrow tolerances, or large components that include large melt flow lengths from the position of the gate. The design of the tool should thus preferably incorporate suitable temperature control zones (flow paths), to provide the desired tool temperature. The temperature control zones of the tool commonly use water for temperatures up to 100 ° C, above which electrical or oil heating is used.

Injection molding is one of the most sophisticated polymer processing operations, with machine costs typically ranging from US $ 50,000 to well above US $ 1,000,000 and tool costs ranging from $ 10,000 to well above $ 100,000. The vital operation of tool equipment is often not given the attention it deserves. If a machine has a poor equipment, then this will affect the production cost, through the cycle time and the rejection speeds of the parts. The equipment of the machine is still considered as black magic, based on the experience of the matrix adjuster or manual mold (ie the person responsible for the adjustment parameters on the machine for injection molding, to achieve a production of acceptable quality). In a typical injection molding manufacturing facility the equipment of the machine is often overlooked with the condition of "getting parts out of the house". This hurried equipment of the machine is often done with inconsistent strategies because different equipmen or adjusters of the matrix or mold have their own personal points of view as to what constitutes an optimal equipment. Manufacturing facilities typically have a high work equipment change at the warehouse level, and thus training and maintaining an adequate level of experience is also at a high cost. . An object of the present invention is to provide a substantially automated organization of at least a part of the injection molding equipment process. Furthermore, it is an object of the present invention to provide the most consistent machine equipment in an automated manner throughout the manufacturing facility. Accordingly, therefore, the present invention provides a method for the automatic optimization of a process of equipping the injection molding machine, of the machine for manufacturing injection molded parts, which includes the steps of: (1) manufacturing one or more parts with the machine; (2) Inspect the parties for defects; (3) reducing the stroke or segment of injection in response to the manufacture of burrs or increasing the stroke or segment of the injection in response to a light weight of the material introduced into the mold; and (4) reducing the injection speed in response to burr formation or increasing the injection speed in response to a light weight of the material introduced into the mold, where either step (4) is employed after the step ( 3) if step (3) is found to have substantially no effect or substantially no additional effect, or step (3) is employed after step (4) if step (4) is found to have substantially no effect or substantially no additional effect, by which defects are reduced. Therefore, if a machine adjuster observes that the formation of burrs or a small weight of material introduced into the mold are not eliminated by altering the stroke or segment (or speed) of injection, the equipment process can be improved. altering the speed (or the route or segment) of the injection. The second invention also provides a method for the automated optimization of an equipment process of an injection molding machine, the machine for manufacturing injection molded parts and including an injection screw and a configurable injection speed, which includes Steps of: (1) Manufacturing one or more parts with the machine; (2) determining a profile of the injection pressure by measuring the injection pressure as a function of the injection time elapsed with the machine configured with a desired, substantially constant injection speed; (3) measure the speed of the injection as a function of the elapsed injection time and determine a profile of the measured injection velocity; (4) defining an average pressure profile from the pressure profile in a regime of the velocity profile of the injection measured substantially constant; (5) adjust the speed profile over at least a portion of a phase of the injection velocity in response to said pressure profile to reduce the differences between the pressure profile and the average pressure profile, so which tends to reduce the irregularities in the profile of the pressure. Preferably step (5) is carried out only in said regime. Preferably steps (1) and (2) are repeated a plurality of times to obtain a plurality of measurements of the injection pressure profile and the profile of the injection pressure is determined from an average of the measurements. Preferably steps (1) to (5) are repeated a plurality of times, whereby the velocity profile is progressively refined.

Accordingly, the velocity profile can be adjusted progressively to reduce or eliminate irregularities in the pressure profile. The step of adjusting the speed profile can be repeated to further reduce such irregularities, to any tolerance that is required. Preferably step (5) comprises increasing the injection speed where the pressure profile is smaller than the profile of the average pressure, and reducing the speed of the injection where the profile of the speed is greater than the profile of the average pressure. Preferably, the profile of the average pressure is linear. Preferably the pressure profile is in the form of a profile of the pressure derived, obtained by the differentiation of the profile of the pressure with respect to time. Therefore, the method is preferably carried out with the derivative with respect to the time of the pressure, instead of the pressure itself. Preferably the method includes determining a relationship between the injection speed and the pressure profile by altering the injection speed around a predetermined speed.

Preferably the ratio includes compensation for changes in the viscosity of the molten material. Preferably changes in viscosity include changes in viscosity that are due to changes in temperature and pressure of the molten material. Accordingly, the response of the pressure profile to the changes to the injection speed can be determined by performing the test injections over a narrow range of injection speeds. Preferably the disturbance of the injection velocity is in predetermined amounts, and more preferably the disturbance of the injection velocity is by + 10% and / or + 20%. Preferably the pressure profile is derived from the hydraulic injection pressure. Alternatively, the pressure profile is derived from the flow pressure of the molten material. Preferably, the method includes the determination of a viscosity model by performing a test of the material, of the molten material for injection. Therefore, for non-Newtonian plastics (actually all plastics) the prediction of the response of the pressure profile to changes in the velocity profile can be improved if the viscosity is measured first. The present invention further provides a method for the automated optimization of a process of equipment of the machine for injection molding, the machine for manufacturing injection molded parts and including an injection screw and a configurable injection speed, the screw that it has a displacement, which includes the steps of: (1) manufacturing one or more parts with the same machine; (2) defining as a first pressure the end of the pressure of the speed control phase and as a second pressure the pressure of the holding or holding time; (3) defining a linear relationship between the pressure and the retention / packing time consistent with the first pressure and the second pressure, between the first pressure and the second pressure; (4) define the packing time as a time of the maximum difference between the pressure of the measured molten material and the linear relationship, or as the switching point or change if the pressure of the molten material increases after the change or switching point; (5) determining a first displacement of the screw which is the minimum displacement of the screw before the time of packing within a clamping / packing phase and a second displacement of the screw which is the displacement of the screw at the time of packaging; and (6) calculating the return or feedback of the difference between the first and second displacements of the screw, whereby a determination of the return or feedback from the measurements of the displacement of the screw in the packing time is allowed. Therefore, the maximum return or feedback - or negative or backward movement of the screw at the point of the transfer of velocity to pressure - can be determined from the displacement of the screw at the time of packing. The present invention still further provides a method for the automated optimization of a process of equipment of the machine for injection molding, the machine includes an injection screw, which includes the steps of: (1) adjusting or setting a holding pressure / Initial packing at a low fault pressure; (2) carry out at least one partial injection cycle; (3) determining the return of the changes in the displacement of the screw during the at least one partial injection cycle; (4) increase the initial retention / packing pressure; and (5) repeating steps (3) and (4) if the return is unacceptably high until the return is reduced to a predetermined acceptable level, or the initial holding / packing pressure reaches the maximum machine pressure. Preferably the initial packing / holding pressure is between 5% and 25% of the end of the pressure of the speed control phase, and a substantially uniform packing pressure is used, and more preferably the initial packing / holding pressure is about 10% of the end of 'the pressure of the speed control phase. Preferably the initial retention / packing pressure is increased between 2% and 25% of the end of the pressure of the speed control phase, and more preferably the initial packing / holding pressure is increased by about 5% of the end of the pressure of the speed control phase. In a preferred embodiment, the method includes measuring the return of a plurality of initial retention / packing pressures, which predict an optimal initial retention / packing pressure from the measurements to minimize the return, and increase the packing pressure. Initial retention at the optimum initial packing / holding pressure. In another aspect the present invention provides a method for the automated optimization of a process of equipment of the machine for injection molding, the machine for manufacturing the injection molded parts and including an injection screw, which includes the steps of: (1) define a retention time equal to a predetermined failure value; (2) carry out at least one partial injection cycle; (3) measure a path or segment of the pressure which is the change in the displacement of the screw between the packing time and the holding time; (4) increase the retention time; (5) repeating steps (3) and (4) until the path or segment of the pressure is stabilized or a part thus produced is acceptable; (6) define a linear relationship between the displacement of the screw and the time consistent with the displacement of the screw in the packing time and the retention time, between the packing time and the retention time; (7) define a cooling time of the gate as a time of the maximum difference between the displacement of the screw and the linear relationship, whereby a value for the cooling time of the gate is provided from the measurements of the displacement of the screw. Preferably the method includes the additional steps of: (8) repeating steps (6) and (7), and defining an initial solidification time between the packing time and the cooling time of the gate; (9) repeating steps (6) and (7), and defining an intermediate solidification time between the packing time and the initial solidification time; and (10) determining an intermediate pressure of the ratio of the screw displacements in the intermediate time and in the cooling or freezing time of the gate, with reference to the packing time. Preferably the value of the retention time used in step (6) is greater than that defined in step (1) by a factor of between 1 and 3.

Preferably the predetermined failure value is the largest of 2 times the injection time and one second. Preferably the stabilization occurs when the path or segment of the pressure changes in less than a predetermined tolerance between the successive measurements. Preferably the retention time is increased in step (4) between 5% and 50%, and more preferably by about 20%. Preferably the predetermined tolerance is between 2% and 10%, and more preferably is about 5%. In one embodiment, the present invention provides a method for the automated optimization of an equipment process of an injection molding machine, the machine for manufacturing injection molded parts and including an injection screw and a configurable injection speed, which includes the steps of: (1) determining an optimum filling that includes: (i) manufacturing one or more parts with the machine: (ii) inspecting the parts for defects; (iii) reducing the path or segment of injection in response to the formation of burrs or increasing the path or segment of the injection in response to light weights of the material introduced into the mold; and (iv) reducing the speed of the injection in response to burr formation or increasing the injection speed in response to light weights of the material introduced into the mold, wherein any step (iv) is employed after the step ( iii) if step (iii) is found to have substantially no effect or substantially no additional effect, or step (iii) is employed after step (iv) if step (iv) is found to have substantially no effect or substantially does not have an additional effect, whereby the defects are reduced; (2) determine an optimum injection velocity profile, which includes: (i) manufacturing one or more parts with the machine; (ii) determining a profile of the injection pressure by measuring the injection pressure as a function of the injection time elapsed with the machine configured with a desired, substantially constant injection speed; (iii) measuring the speed of the injection as a function of the elapsed injection time and determining a profile of the measured injection velocity; (iv) defining a profile of the average pressure from the pressure profile in a regime of the velocity profile of the injection measured substantially constant; (v) adjusting the speed profile over at least a portion of a phase of the injection velocity in response to the pressure profile to reduce the differences between the pressure profile and the average pressure profile, thereby 'tends to reduce irregularities in the profile of the pressure. (3) modify an equipment or intermediate facility of the post-velocity control phase obtained after steps (1) and (2) in response to the quality defects detected in said manufactured parts with the adjustment or intermediate equipment to reduce the defects; (4) a method of reducing the return to an acceptable level to determine a critical retention / packing pressure, which includes: (i) adjusting an initial retention / packing pressure to a low failure pressure; (ii) carry out at least one partial injection cycle; (iii) determining the return of the changes in the displacement of the screw during at least the partial injection cycle; (iv) increase the initial packing / holding pressure; and (v) repeating steps (iii) and (iv) if the return is unacceptably large until the return is reduced to a predetermined acceptable level, or the initial holding / packing pressure reaches the maximum machine pressure. (5) deduct the solidification time of the material from the screw displacement measurements to determine an optimum clamping / packing pressure profile, which includes: (i) defining a retention time equal to a predetermined failure value; (ii) carry out at least one partial injection cycle; (iii) measuring a path or segment of the pressure which is the change in the displacement of the screw between the packing time and the holding time; (iv) increase the retention time; (v) repeating steps (iii) and (iv) until the path or segment of the pressure is stabilized or a part thus produced is acceptable; (vi) define a linear relationship between the displacement of the screw and the time consistent with the displacement of the screw in the packing time and in the retention time, between the packing time and the retention time; (vii) define a time of cooling or freezing of the gate as a time of the maximum difference between the displacement of the screw and the linear relationship, whereby a value for the freezing time of the gate is provided from the measurements of the displacement of the screw; (6) modify a preliminary equipment adjustment of a post-pressure control phase obtained after (1) to (5) in response to the defects detected in the parts manufactured with said adjustment or preliminary equipment to reduce the defects. Preferably step (iii) of step (4) includes determining the return of measurements of screw travel at the time of packing, which includes the steps of: (a) manufacturing one or more parts with the machine; (b) defining as a first pressure the end of the pressure of the speed control phase and as a second pressure the pressure of the retention time; (c) defining a linear relationship between the holding / packing pressure and the time consistent with the first pressure and the second pressure, between the first pressure and the second pressure; (d) defining the packing time as a time of the maximum difference between the pressure of the measured molten material and the linear relationship, or as the switching point or change if the pressure of the measured molten material increases after the switching point or change; (e) determining a first displacement of the screw which is the minimum displacement of the screw before the time of packing within the retention / packing phase and a second displacement of the screw which is the displacement of the screw at the time of packaging; and (f) calculating the return of the difference between the first and second displacements of the screw, whereby a determination of the return from measurements of the displacement of the screw in the packing time is allowed. Preferably step (5) includes the additional steps of: (viii) repeating steps (vi) and (vii), and defining an initial solidification time between the packing time and the freezing time of the gate; (ix) repeating steps (vi) and (vii), and defining an intermediate solidification time between the packing time and the initial solidification time; and (x) determining an intermediate pressure from the ratio of the screw displacements in the intermediate time and in the freezing time of the gate, with reference to the packing time. In each of the above aspects of the present invention, the method preferably includes: determining the response time of the machine speed control, and employing time steps equal to or greater than said response time. Preferably the time steps are greater than 1.5 times the response time, and more preferably equal to 2 times the response time. In the above aspects of the present invention, the pressure of the molten material of the nozzle, the hydraulic pressure of the injection cylinder, the forward propulsion force applied to the screw, or any other measure proportional to or equal to the pressure of the molten material of The nozzle can be used as a measure of, instead of, or to determine, the injection pressure. Preferably the hydraulic pressure of the injection cylinder is used as a measure of or to determine the injection pressure. For the invention to be understood more clearly, preferred embodiments will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic representation of the machine optimization method, automated, according to the preferred embodiment of the invention. the present invention; Figure 2 is a graph schematically illustrating the influence of the speed and the path or segment of the speed during the filling process; and Figure 3 shows a profile of the typical pressure resulting from a pressure profiling method according to a preferred embodiment of the present invention.

Detailed description of the invention The present invention (referred to as Optimization of the Automated Molding or AMO) is used in the equipment or establishment the profiles of the speed of injection / filling and the pressure of retention / packaging. Other parameters of injection molding machine, including barrel or cylinder temperatures, mold temperatures, cooling time and rotary screw speed are currently the responsibility of the die or mold adjuster. The fundamental principle of AMO speed optimization is profiling considering an inferred mold geometry, derived from the pressure differential. The optimization of the phase of the pressure is used for profiling considering a solidification of the inferred polymer, derived from an accurate measurement of the displacement of the screw. The AMO determines the characteristics of the material and the machine on the line from the machine without the need for interaction with the user, leading to optimized profiles that are "in phase" with the dynamic characteristics of the machine, the material and the geometry of the mold. Figure 1 is a flow chart summarizing the role of the AMO method according to a preferred embodiment. In Figure 1, the various inputs are the computer-aided engineering (CAE) model 10, the Machine Information 12, the Material Information 14, the Processing Conditions 16a and 16b, and the Speed and Timing Estimates. Travel or Segment of Speed 18. The inputs are used in an optimization stage (MF / OPTIM or "Mold Flow Optimization"). The feedback during the design of the part is indicated by a dashed line 20. The AMO method of the preferred mode has six phases of process optimization: 1. Speed and Segment or Speed travel, based on a constant speed one-step; 2. Profiling of the Injection / Filling Speed; 3. Elimination of the speed defect; 4. Determination of the size of the packing pressure; . Determination of freezing or cooling of the gate and profiling of the pressure; 6. Elimination of the defect of the pressure phase. In general, if the screw travels too close to the outlet through the bottom, the profile of the screw load is shifted backwards. This takes two shots or weights of material introduced into the mold, since the first can not be plasticized to the new position. If the cycle time is too long, the AMO will ignore the cycle. This six phases are summarized as follows: 1) Determination of the route or segment of the velocity and speed adjustments: This phase assumes that a substantially uniform velocity profile is used, and that the tool can be properly filled using such a profile. The rules used within this phase converge on the adjustments that produce a "good part", if a poor estimate of the velocity or volume segment is introduced. A route or speed segment of "critical filling" is determined, to ensure that packing does not occur during the speed-controlled injection stage. Critical filling is the point at which the part is just filled justly. Sometimes the polymer inside the cavity is overfilled, but it does not show any visible defect. The profile of the initial velocity is generated from: i) an estimate of the path or segment of the velocity, entered directly or as a partial volume, and ii) the velocity, typically 50% of the maximum capacity of the machine. The segment or load path is initially set equal to approximately 1.1 x travel or speed segment. At this stage, other defects related to speed and related to the pressure phase are ignored. 2) The first procedure in this phase is to determine an estimate of the relationship between the injection speed and the average difference of the profile of the pressure of the molten material in the nozzle. The pressure of the molten material in the nozzle can be derived from the hydraulic injection pressure multiplied by an intensification ratio of the screw. The speed of the injection is disturbed around the speed of phase 1, in predefined percentages, for example ¿10%, + 20%. The next phase is to determine the profile of the nozzle pressure, for the stable processing conditions obtained using a uniform velocity profile, and then differentiate the profile. The response time of the machine is determined from the velocity profile. Using the information of the pressure differential during the speed stage, an optimized speed profile is obtained. The profile is generated in the corridor and the two-stage channel, and are combined using a verification of the response. (3) This phase involves the elimination of the defect related to speed. The main objective is to vary the profile of the speed to achieve a part without defects related to speed. Defects related to speed are corrected. Defects include, blasting, delamination, bright marks, burn marks, welding lines, burr formation, etc. Comment: the user simply selects the defect. In the case of defects in conflict, it is necessary to converge on a compromise point. One part (good quality immediately) is the minimum, the maximum depends on the user's evaluation. Three parts are frequently typical. 4) This phase determines a critical packing pressure, ie a level of pressure that will help to eliminate the backflow of the material, outside the cavity. The focus is to start down or slow and increase the pressure until the desired level is reached. 5) This phase determines a freezing or cooling of the inferred gate, the initial solidification and the intermediate times. The times are determined by the precise verification of the movement of the screw with a profile of the uniform pressure applied. The freezing time of the gate and the time of the initial solidification is found, and the packing retainer profile is generated. This process does not require the weighing of some of the molded parts. The pressure of the cavity is inferred from sensors other than the cavity, specifically the hydraulic pressure and the movement of the screw. 6) This phase involves the elimination of the defect related to pressure. The main objective is to vary the profile of the pressure to achieve a part without defects related to pressure. Defects related to pressure are evaluated. These are formation of burrs, depressions, distortions, and dimensional tolerance (too big / too small). Phases 1 to 3 are started with zero or very low packing pressure, typically only for 1 second. These six phases are described in more detail below.

Phase 1: This phase includes the determination of the segment or travel of the speed and the adjustments of the speed. A profile of the constant speed that leads to a complete part is found. All defects (apart from the formation of burrs and a small weight of material introduced into the mold) are ignored. The pressure profile is initially set to substantially zero.

Phase 1.1: User Estimation The user is suggested to provide an estimate of the partial volume. The volume must be obtained easily from the manufacturer of the mold or matrix. The volume is divided between the area of the screw to give a tour or segment of the speed; alternatively, the mold adjuster or matrix can directly estimate the path or segment of the speed. An exact estimate of the partial volume can also be obtained from a Computer Aided Engineering (CAE) model. The route or segment of the estimated speed is compared with the path or maximum segment of the machine to ensure that the machine is of a reasonable size for the part that is being made. The following checks are made: load segment > segment maximum speed segment > 90% of the maximum segment segment of the speed < 5% of the maximum segment The user also estimates the screw speed. The speed could be estimated by a 2D flow analysis, but in the present this is seen as something that is not guaranteed, because the user might have to enter more information (for example the information of the material, the length of the flow path). dominant) . In addition, the user can be expected to have a reasonable idea of the correct speed that has to be used based on their experience. A flat fill profile is generated from these estimates; the VP point is configurable as a percentage of the estimated route or segment of the speed (the failure is 20%).

Phase 1.2: Estimation Optimization This phase aims to refine the estimate of the user of the route or segment so that a complete part is made (without burrs or short). Configurable adjustment parameters are used in all the steps below. After each change to the set points, a configurable number of parts are made trying to ensure permanent status conditions. The method of this phase was developed from the discovery of a relationship between the speed of injection and the route or segment of the speed, and the optimization of the filling of the material. This relationship is shown schematically in Figure 2. The following steps summarize this phase. 1. A part is done, and the feedback about the quality of the part is required of the user. 2. If the part is short, the path or segment is increased by moving the point of change of the VP. 3. If the part has burrs, the path or segment is reduced by moving the VP change point. 4. If the part is both short and has burrs, the user is questioned about more feedback: if the user thinks there is total freezing of the molten material, the speed is increased and the path or segment reduced, otherwise the opposite occurs . 5. If the part is whole, this phase is complemented. 6. A part is made with the new set points, but this time the user has the opportunity to specify that no improvement has occurred. If the user specifies "No Improvement", the following steps 7 to 9 are undertaken. 7. If the previous answer was "short", then the speed and the route or segment are increased. This takes into account that the short size has been caused by the total freezing of the molten material. 8. If the previous response was burr formation, then the speed and travel are reduced. 9. If the previous response was burr formation and short size, the speed is reduced and the path increased. Changes are made twice to integrate the previous modifications (which are now known to be incorrect). 10. If the user does not specify "None Improvement", but instead repeats the evaluation of the previous quality, then the modifications of the previous set point are repeated. 11. If the user specifies a short shot or small weight of material inserted into the mold when the burr formation was previously specified (or vice versa), the adjustment factor is halved to allow the adjustment points to converge. A configurable minimum adjustment factor is used to prevent the adjustments from becoming insignificant. 12. If the path or segment of the speed increases, causes the VP change point to be less than a configurable percentage of the path or segment of the speed, the path or segment of the load is increased before the next part is made. 13. When the path or segment of the load is increased, the next part is ignored, since the machine for the injection molding may have finished the plasticization at the now incorrect position. 14. If no improvement is selected on three consecutive occasions, the procedure stops and the user is suggested to modify the mold / molten material temperatures.

Phase 1.3: Obtaining Critical Fill After phase 1.2 is completed, there is a complete part. However, the part may be overfilled, which is often the cause of internal stresses. A too high packing / holding pressure will be required to eliminate feedback or feedback. This phase tries to eliminate this problem by obtaining a state of "critical filling". First, the path or segment is reduced, as when the user has indicated burr formation. This is repeated each time the user indicates a complete part. Eventually, a point is reached where the path or segment is small enough to cause a short shot or small weight of the material introduced into the mold to occur. When the user indicates a short trip, the route or segment is increased (it should be noted that the change in the route or segment is smaller than previously due to the convergence). When the part recovers the "filling", the critical filling has been reached.

Phase 2: Profiling of Injection / Filling Speed This stage places the "steps" in the velocity profile. These steps help maintain a constant velocity of the flow, which in turn minimizes internal stresses in the molded part. Loads are imposed on the profile of the velocity of the raw materials found to ensure that it slows down at the end of the filling, which is known to improve the burn marks, in the channel or corridor (to prevent blasting). This phase is used after phase 1, and if the velocity profile is constant velocity and pressure (nozzle or hydraulics) and the displacement transducer data is filtered and available. It is assumed that the displacement at which the inflection points in the pressure curve are located does not change significantly when the velocity is altered. Prior to the calculation of the velocity profile, the pressure information from a number of parts is stored and then averaged, in an attempt to smooth the deviations between the cycles. A number of parts can also be ignored before this average is carried out to achieve permanent status conditions; both the number of parts to be averaged and the number to be ignored are configurable, with faults of 1 and 0 respectively.

Phase 2.1: Determination of Material Properties If the AMO is to outline the control of the speed, then it is necessary to know how big the steps are. Therefore, it is necessary to determine the relationship between the speed set point and the magnitude of d £. For example, if dg must be increased in dt of 10%, this relationship is required to determine how high the velocity step should be. The following steps are taken to determine the relationship between speed and dp: dt 1. Percentage deviations of speed are read from the configuration register; 2. the speed is altered, it becomes a part, and the main magnitude of the answer of djo (during dt speed control) is recorded; 3. If more experiments are required, the speed is altered according to the following percentages in the configuration record, and step 2 is repeated. If not, the speed is readjusted to the user's estimate, and step 2 is repeated one last time. 4. A linear regression is used to find an equation that relates the values of djD averages dt recorded with respect to the speed adjustment points used.

Phase 2.2: Determination of the Induction Time of the Displacement The data recorded before the time of the induction must be ignored, since essentially nothing is happening, so that it is necessary to determine the displacement induction time, which is a measure of the time required for the screw to begin the movement after the data acquisition system receives a signal to start the injection. The displacement induction time is found when the displacement data indicates that the screw has moved beyond a small threshold distance. The threshold is calculated as a percentage of the path or segment of the load (for example 0.1%); this threshold should be typical of the noise level of the displacement transducers.

Phase 2.3: Determination of Pressure Induction Time Similarly, the time of pressure induction is a measure of how long it takes the pressure to start the increase after the data acquisition system receives a signal to initiate the injection. This can be longer than the time of induction of displacement if the decompression is used at the end of the plasticization. The pressure induction time is found when the pressure data indicates that the screw has increased above a certain small threshold above the initial pressure (this takes into account the zero error of the transducer). The threshold is calculated as the minimum of a percentage (for example 0.1%) of the maximum pressure of the machine and a value of the absolute pressure (for example of 0.1 MPa). This threshold approaches the level of noise on the pressure transducers.

Phase 2.4: Determination of the Response Time of the Machine The injection molding machine can not follow the steps in the speed profile if the steps are too short. This minimum time is defined in terms of the response time of the machine. Therefore, it is necessary to determine the response time of the machine, which is a measure of the time required by the screw to obtain a given speed.

The response time is simply the time in which the velocity data exceeds 85% of the target or target speed.

Phase 2.5: Determination of the Pressure Derivative (Time wrt) As described above, it is desirable to keep the front velocity of flow reasonably constant by introducing steps in the velocity profile.

The size and location of these steps is based on the dg calculations. The amount of dg gives a dt dt indication of the geometry of the part as observed by the advance of the front of the flow. When dg is increased, the front dt of the flow is confronted with a narrowing in the cross-sectional area of the cavity. A Savitsky-Golay smoothing filter of 33 points is used to soften the pressure information. The square root of all the pressure information is taken. This allows large dg values to be increased at a much faster rate when the speed is increased more than the average dg dt values. It should be noted that in Phase 1 a linear relationship was calculated between the average dg and the dt setpoint of the velocity. The amount of dg is calculated by subtracting the next value of the pressure from the value of the common pressure, and dividing by the sampling period.

Phase 2.6: Determination of Gate Time The knowledge of when the flow front reaches the gate allows the method to have separate velocity profile steps for the corridor or channel system. The "time of the gate" is therefore the time in which the front of the flow reaches the gate. The time of the gate is taken as the maximum of the three calculations described later. The maximum is used to try to ensure that a point away from the initial dg "hump" is found. dt 1) Time zero of dg: Between the induction time and 50% dt of the injection time, dg is verified to observe dt when it decreases below zero. The time of the gate is the point at which it rises again above zero; 2) "low or small time" of dg: the maximum dg between the dt dt induction time and 50% of the filling time is found. The average dg between the time in which this maximum dt occurs and the end of the filling time is found. Where dg first decreases below this average is the time of the gate. Note that the low or small time is always less than the zero time, so this calculation is done only if d £ never falls below zero, and dt 3) Stabilization time of the speed: Between 70% of the time of filling returns to the time of induction, an average movement (over a three-point window) of the velocity data is calculated. The gate time decreases where the average movement is out (μVei + 12sVei) where μve? and sve? they are calculated during a portion of the assumed permanent state of the velocity data (for example between 70 and 90% of the filling time). In other words, the method seeks the point at which the velocity first becomes stable, with an upper limit of 70% of the imposed filling time.

Phase 2.7: Determination of Graduated or Staggered dp / dt Profile As described above, it is desirable to maintain the front speed of the flow reasonably constant by introducing steps in the velocity profile. The steps in the velocity profile should correspond to the cross-sectional area of the cavity, which in turn could have a strong relationship with the graduated or stepped dg dt profile. The graduated dg profile approaches dt to the calculations of dg (after gate time) dt as a series of steps. The number of steps is limited by a configurable limit, and the size of the necessary steps does not depend on the response time of the machine. The maximum of the dg between the time of the gate gate and the end of the fill is found. A configurable percentage (for example, 10%) of the value? of the maximum dg is calculated. The number of steps n is dt initialized to 0, and the counting indices of the data i and k for the induction time and 0, respectively. The index i is used to store the starting position of each step in the data of dg, and k is used to iterate through the data within each step. A value of initial dg sum is stored for time = i + k. dt if I Bum / k - - [i + Jc + l] | > ?, then the step of profile n is dt set equal to sum / k, n is incremented, i is set to i + k, and the method returns to phase 2.4. Otherwise, sum is dp increased by - [i + Jc + l], k is incremented, and the dt method returns at the beginning of this phase (2.7) unless k = filling time. The method reaches this stage when k = filling time. The step of the final profile = sum / k, and any steps of the negative profile are set to zero.

Phase 2.8: Determination of Graduated or Staggered Speed Profile Graduated or staggered velocity profiles can be introduced into the machine's controllers as set points, and should attempt to maintain a constant flow front velocity when the polymer moves into the cavity. The speed profile determined in this section is based on the graduated or stepped dg profile determined by the previous dt phase, and does not take into account the response time of the machine. From the graduated dg or graduated dg pressure profile, the following parameters are calculated. 1. dg Average dt 2. dg Maximum dt 3. dg Minimum dt 4. For each step n in the dg profile, the step of the corresponding dt speed, where: velocity = (dg avg - dg) / (dg max - dg in) dt dt "dt dt This gives the profile of the scaled speed about 1, where 1 is the average speed (the user 's estimate).

Phase 2.9: Determination of the Speed of the Corridor or Channel The speed of the corridor or channel is the first step in the velocity profile. The speed of the runner or channel is chosen using the ratio of the maximum dg dt between the time of the induction and the time of the gate, and the average pressure of the profile of the graduated or stepped pressure (see Phase 2.7: Determination of the Profile of dp / dt Graduated or Staggered). When the ratio increases, the speed of the corridor or channel is reduced, the ratio is limited so that the speed of the corridor or channel is never less than the average speed after the gate.

Runner speed = 1 - 0.1 (dg max / average of the profile of graduated or stepped pressure) Phase 2.10 Determination of the End of the Filling Speed A heuristic rule for the adjusters of standard molds or matrices is to decelerate the speed towards the end of the filling. This helps prevent air from getting trapped inside the cavity, and therefore helps prevent burn marks. It also helps ensure that the part is not overfilled, and seeks a smoother transition to the packaging / retention phase. The end of the filling speed is the last step in the velocity profile. The fault is the last 10% of the filling, although this is configurable. A ratio of dg during the end of the dt-filled segment compared to dg in the 10% of the immediately previous dt-fill is calculated. If this ratio is large, the speed at the end of the fill will be slow, but limited to 50% of the previous speed. If the ratio is low (ie dg decreases at the end of filling) the last step of the speed is limited to the immediately preceding speed, ie the speed is not increased at the end of the filling.

Phase 2.11 Response Time Compensation The graduated or stepped speed profile determined in the previous phase assumes that the machine has an infinitely fast response to changes in the set point. Of course, this is not realistic, and so the steps must be prolonged or extended to take the actual response time into account. The narrow steps together in magnitude are united since the difference is likely to be brought down or upset by the error in the controller. If such small differences were left in the velocity profile, the algorithm could lose credibility. A maximum number of steps are specified since almost all IMM controllers on the market today are limited in this way. This phase lengthens the step size of the velocity profile calculated in the previous phase if it is smaller than the response time calculated in Phase 2.4: Determination of the Response Time of the Machine. In addition, the steps that are closer together in magnitude than the desired threshold are joined. If at the end of this process there are more steps than allowed, this process is repeated with a longer response time and a larger threshold. Each step in the velocity profile is linked to the next step, if the step length is less than the response time. The steps are joined until the length of the joined step is greater than or equal to the time of the response. The resulting step has a velocity that corresponds to the weighted speed of the two steps. For example: new Speed = (time 1 x speed 1 + time 2 x speed 2) / (time 1 + time 2) This process is repeated until all the steps have been verified for the time of the response. If the duration of the last step is too short, it is linked with the second final step. The profile is scaled back to the previous maximum and minimum. This scalar step can be limited by a configuration registration parameter so that small steps are not run or used out of proportion. The scalar step is also maintained at l (the user's estimate) as the average value. The magnitude of each step of the speed is compared against the magnitude of the next step. If the difference is less than 10% of the maximum speed, the steps are joined as described above, and the step of scaling back the profile is returned. The number of steps in the profile is verified. If the same is larger than the maximum allowed number, this stage is repeated with a 20% larger response time, and a 20% speed difference threshold instead of 10%.

Phase 2.12 Conversion Time to Displacement, and Velocity with respect to Physical Units Most controllers of injection molding machines accept speed profiles in terms of the displacement of the screw (instead of time). Also, the velocity values are commonly normalized, and need to be scaled to the physical units (eg mm / s) before they can be passed to an IMM controller. A conversion factor, a, is calculated using the relationship found in Phase 1. For each speed step n: velocity = estimated speed by the user x ((velocity - 1) xa + 1) The result is in units YES (m / s). To convert the times to displacements, a conversion factor between the path or segment of the velocity at the set point and the number of samples during filling is calculated. The conversion factor does not have to take into account the most recent velocity magnitudes in the profile that is different from those used when the part was made, since the changes in the velocity step must be related to the position of the front of the flow, not with the time in which they occurred. Adjust the offset of each step from the load path using the conversion factor. displacement = load path - conversion factor x number "of step samples Phase 3: Elimination of Speed Defect At this point, the magnitude of the steps of the speed is an arbitrary percentage of the maximum speed of the machine (although they must be approximately correct in a related way). As a result, defects in molding could occur. This stage attempts to rectify the defects related to the velocity profile by executing heuristic rules in response to feedback by the user. There are two prerequisites: first that a part has been made with the profile of the speed of phase 2, and secondly that the feedback by the user has been provided considering the quality of the part produced. Feedback is one of the following defects: no defects, burr formation, light weight of the material introduced into the mold, welds, burns, trickling, scratching, gloss, delamination, and registration notches. It is assumed that changing the average magnitude of the speed set point does not affect the position of the inflection points in the pressure curve. The following answers are made for each defect, making another molding to ensure a good quality. 1. Burr formation: Reduction of all speed steps by a multiplier. 2. Lightweight: Increase of all speed steps by the multiplier. 3. Welding: The same as light weight. 4. Burns: The user is requested to provide more information; the mark of the burn is near the gate, of repeated design in all its extension, or near the filling end. If the burn is of repeated design in all its extension, all the steps of the speed are diminished. If the burn is near the end of the fill, the screw speed is reduced at all points in the last 25% of the fill profile. The burn marks near the gate can be treated in a similar way, except that the first 25% of the speed points are altered.

. Blasting: reduction of all points of the speed in the first 25% of the speed profile. 6. Scratch marks: as for burn marks, except that the user provides a selection of "pattern repeated throughout its extension" or "at the end of filling". 7. Bright marks: the increase of the full speed profile by a multiplier. 8. Delamination: reduction of the full speed profile by a multiplier. 9. Registration notches: As for bright marks.

The basis of the rule fails if the desired action can not be taken; in this case the user is informed of the situation and is given a notice of how to solve it (through the help on the line).

Phase 4: Obtaining the Correct Packing Pressure At this point, the injection molding machine is using low fault pressure. The correct level of pressure to be used during the pressure control stage that prevents the return is desirable. This stage does this, but it does not profile the pressure control adjustment points, or find the time that the pressure control must be maintained. There are three prerequisites: firstly, that Phase 3 is completely successful, secondly, that the maximum packing pressure is known, and third, that permanent conditions prevail.

Phase 4.1: Reduction of the Travel or Segment of the Speed and Adjustment Points of the Initial Pressure Control.

The pressure control time is set to twice the time of the invention (or 1 s, whichever is greater), the pressure level is 5% of the end of the filling pressure, and a profile of the pressure of "rectangular" shape is used. In addition, to ensure that the molten material is not compressed during filling, the path or segment of the speed is reduced by 2%, in line with the practice of common molding.

Phase 4.2: Determination of Return The return or feedback is defined as the distance traveled by the screw in the reverse direction to the injection during the control of the pressure after the packing time. This is caused by the set point of the pressure control that is less than the return pressure exerted by the molten material on the front of the screw. It is desirable to eliminate the return to prevent the polymer from flowing out of the cavity, which is known to be a cause of sinking, warping and other dimensional problems. The maximum return displacement is discovered by finding the packing time. The return then is the distance from the minimum displacement before the packing time to the displacement in the packing time. If the return is not negative, it is set to zero. The first task is to determine the packing time by examining the pressure of the molten material in the nozzle (or the hydraulic pressure). The equation of a straight line from the pressure in time of the switching point or change of v / p with respect to the pressure in the retention time is calculated, and then the time to the maximum difference between the straight line and The recorded pressure curve is the packing time. However, an increase in pressure after the change of v / p indicates that no return has occurred. In this case, the packing time is the point of change or switching of v / p. This does not mean that the packing time is always at the v / p switching point when a return does not occur.

Phase 4.3: Elimination of Return This procedure is used where the return is greater than zero. If there is no return, the level of pressure is acceptable. The initial packing / clamping pressure is increased by 5% of the end or end of the pressure of the speed control phase (or "end or end of the filling pressure"). Phase 4.2 is then repeated until the difference between the return for the shot or material weight introduced in the current mold and the shot or weight of material introduced in the final mold is less than a configurable percentage, or until the maximum pressure of the machine is reached. This procedure should not fail, since the return will only occur if the filling pressure is significantly higher than the holding / packing pressure. Therefore, a holding / packing pressure must be obtainable from this machine.

Phase 5: Estimation of retention time The control time of the gate pressure is determined by means of an adjustment of the end point between the "packing" time and the "search time" using the recorded data up to the "holding time".

Phase 5.1 Determination of Gate Freezing Time and Retention Time At this point, the retention time is going to be taken as being two times the injection time. This is an arbitrary value, and in most cases it is too short. The objective of this stage, therefore, is to find a more accurate retention time, because the short retention times can lead to defects in the molding, such as sinking marks, since the polymer will be able to reflow out of the cavity before solidification occurs. In addition, although phase 5 estimates the freezing time of the gate, the procedure is based on the retention time of the current that is longer than the freezing time of the gate. An arbitrarily long retention time can not be used since there is a slight risk of damage to the tool. The retention time is increased by 50% of the actual or actual value of each shot or weight of material introduced into the mold, until the forward movement of the screw between the packing time and the retention time converges. Convergence is defined as a change of less than 5% in movement from one shot to the next. The current or actual time is chosen (instead of the old time) to allow the gate freeze estimate to be more accurate. Sometimes screw movement will not converge for a reasonable retention time, since there may be slippage on the valve with retainer ring or the polymer below the gate (for example in the runner or channel system) compression may continue after the gate has frozen. To prevent the retention time from increasing without limit, a maximum of 30 s is used.

Phase 5.2: Pressure Profiling The pressure profiling is designed to find the initial solidification time ts and the freezing time of the gate, and an intermediate time, ti, between these two. In addition, the desired pressure Pi a is calculated, while the pressure at tf is set to zero, since any pressure applied after the freezing time of the gate will have no effect on the quality of the part after this time. Figure 3 shows the shape of the resulting profile, where the point corresponding to ts is indicated in 30, Pi and ti in 32, tf in 34 and the pressure level determined in the previous step in 36. Two prerequisites are that the level of the pressure and the retention time have been determined. The profiling of pressure control set points helps prevent packing of the part when the polymer in the cavity cools, since the pressure will be applied to a smaller area of molten material when cooling progresses. The internal stress of the part can also be improved, since a more similar force will be applied to each fraction of the cooling mass. The point in time ti helps to more accurately estimate the rate of cooling, since it is unlikely to be linear. The freezing time of the gate tf is determined using the end point settings on the pressure and displacement data. An additional end point adjustment between the packing time and tf "on the displacement data gives ts, and at a final endpoint adjustment (again using the displacement information) between ts and tf" gives ti. Pi is determined from the following calculation: P l - POpg \ Dpackage time - freeze time where Dt? emPo packs or is the displacement of the screw at the time of packing, the interim time is the displacement of the screw to you, the freezing time is the displacement of the screw to tf ", and Porig is the pressure found in Phase 4 If the freezing time of the gate can not be found, the control time of the original pressure is used in place of it.

Once the packing time is set, the displacement curve is analyzed to determine the freezing time of the gate. The search time is greater than or equal to the retention time. It is determined by drawing a line of constant displacement from the end of the recorded data to 3 x (retention time - packing time) + retention time, and also drawing a line extrapolated from the displacement curve between 75% up 95% of the time locations (m_). The gradient of the adjustment line of the resulting end point (mE) is then compared with m_, and the search time is reduced until mE > k X md, where 1.3 < Jfc < 3.5 and preferably k = 2. This technique allows a more accurate estimation of the freezing time of the gate without increasing the current retention time. The displacement of the packing is the distance moved by the ram after the packing time, and the freezing time of the gate is the maximum difference between the final adjustment line and the recorded displacement curve.

Phase 6: Removal of Defects Related to Packaging / Retention After Phase 5 is finished, there is still some possibility of quality defects remaining. However, the present defects should not be related to the phase of the speed control (filling), since these were eliminated in Phase 3. The defects that are related to the set points of the pressure control are: Training Burr Compression Sink Dimensional Tolerance A base of a simple rule is used to eliminate the defects listed in the introduction. The basis of the rule does not alter the shape of the profile - it is simply "stretched and oppressed". These bases of the rule are: Burr formation: reduce the magnitude of the profile by 10%. Combalance: Decrease the magnitude of the profile by 5%. Sinking: Increase the magnitude of the profile by 5%.

The time of the pressure control is also increased by 5%. Dimensional Tolerance: If the part is too large, the magnitude of the profile is reduced by 5%. If the part is too small, the magnitude increases by 5%. In conclusion, the AMO allows the optimization of the process to be carried out quickly by the molders. The optimization of the process is "in phase" with the current process, that is to say, it includes the specific parameters of the machine, such as the leakage from the poor control of the speed, with retaining ring, using the processing conditions real. Therefore, the AMO: • provides the equipment of the machine consistent that allows operators with little experience in the adjustment of the mold or die, optimize the equipment of the machine; • reduces the requirement of experience for the job, that is, the experience is no longer necessary to use an equipment procedure; • provides the optimization of the process in each part of the molding facilities; • provides a better integration of the mold design and part production, with a continuation of Moldflow's commitment to bring the benefits of the simulation upstream, into the world of the product designer and link or relate the simulation downstream in the production environment; and • provides a more facilitated installation on modern speed controlled injection molding machines. Process information of the machine is obtained from the standard machine transducers. The AMO optimizes the profiles of the speed and pressure phase. The profiling of the speed helps the elimination of the formation of burrs, the short shots or the light weights of the material introduced in the mold, molecular separation / reddish tone of the gate / extension marks, marks of stripes, delamination / formation of flakes, bright / shiny bands, burn, trickle, sinking and warping marks. The profiling of the speed also optimizes the repeatability of the process, the injection time and the strengthening force. The profiling of the pressure helps the elimination of burr formation, warping, variation, sinking marks and demolding. The profiling of the pressure optimizes the critical dimensions and the backflow of the polymer. Accordingly, the AMO allows machine operators with a small prior mold adjustment experience to equip the machine for injection molding in approximately 25 to 40 cycles. The AMO will help eliminate most molding problems without the need for an experienced molding adjuster or matrix. It automates the machine equipment procedure by determining the optimal processing conditions by intelligently interpreting the process measurements on the line. Modifications to the invention can be made as will be apparent to a person skilled in the art of injection molding and methods of equipping the machine for injection molding. These and other modifications can be made without departing from the scope of the present invention, the nature of which can be ascertained from the foregoing description and drawings. It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following

Claims (39)

1. A method for the automatic optimization of an equipment process of the injection molding machine, the machine for manufacturing injection molded parts, characterized in that it includes the steps of: (1) manufacturing one or more parts with the machine; (2) Inspect the parties for defects; (3) reducing the stroke or segment of injection in response to the manufacture of burrs or increasing the stroke or segment of the injection in response to a light weight of the material introduced into the mold; and (4) reducing the injection speed in response to burr formation or increasing the injection speed in response to a light weight of the material introduced into the mold, where either step (4) is employed after the step ( 3) if step (3) is found to have substantially no effect or substantially does not have an additional effect, or step (3) is employed after step (4) if step (4) is found to have substantially no effect Effect or substantially does not have an additional effect, by which defects are reduced.

2. A method for the automated optimization of an equipment process of an injection molding machine, the machine for manufacturing injection molded parts and including an injection screw and a configurable injection speed, characterized in that it includes the steps of: (1 ) manufacture one or more parts with the machine; (2) determining a profile of the injection pressure by measuring the injection pressure as a function of the injection time elapsed with the machine configured with a desired, substantially constant injection speed; (3) measure the speed of the injection as a function of the elapsed injection time and determine a profile of the measured injection velocity; (4) defining an average pressure profile from the pressure profile in a regime of the velocity profile of the injection measured substantially constant; (5) adjust the speed profile over at least a portion of a phase of the injection velocity in response to said pressure profile to reduce the differences between the pressure profile and the average pressure profile, so which tends to reduce the irregularities in the profile of the pressure.

3. A method according to claim 2, characterized in that step (5) is carried out only in said regime.

4. A method according to any of claims 2 or 3, characterized in that the steps (1) and (2) are repeated a plurality of times to obtain a plurality of measurements of the injection pressure profile and the profile of the injection pressure is determined from an average of the measurements.

5. A method according to any of claims 2 to 4, characterized in that the steps (1) to (5) are repeated a plurality of times, whereby the profile of the speed is progressively refined.

6. A method according to any of claims 2 to 5, characterized in that step (5) comprises increasing the injection speed where the pressure profile is smaller than the profile of the average pressure, and reducing the injection speed in where the profile of the pressure is greater than the profile of the average pressure.

7. A method according to any of claims 2 to 6, characterized in that the profile of the average pressure is linear.

8. A method according to any of claims 2 to 6, characterized in that the profile of the pressure is in the form of a profile of the derived pressure, obtained by differentiating the profile of the pressure with respect to time.

9. A method according to any of claims 2 to 8, characterized in that the method includes determining a relationship between the speed of the injection and the profile of the pressure by altering the injection speed around a predetermined speed.

10. A method according to claim 9, characterized in that the ratio includes the compensation of changes in the viscosity of the molten material.

11. A method according to claim 10, characterized in that changes in viscosity include changes in viscosity that pertain to changes in temperature and pressure of the molten material.

12. A method according to any of claims 9 to 11, characterized in that the disturbance of the speed of the injection is in predetermined quantities.

13. A method according to claim 12, characterized in that the disturbance of the injection velocity is + 10% and / or + 20%.

14. A method according to any of claims 2 to 13, characterized in that the profile of the pressure is derived from the hydraulic injection pressure.

15. A method according to any of claims 2 or 13, characterized in that the profile of the pressure is derived from the flow pressure of the molten material.

16. A method according to any of claims 2 or 15, characterized in that the method includes the determination of a viscosity model by carrying out a test of the material, of the molten material for injection.

17. A method for the automated optimization of a process of equipment of the machine for injection molding, the machine for manufacturing injection molded parts and including an injection screw and a configurable injection speed, the screw having a displacement, characterized because it includes the steps of: (1) making one or more parts with the machine; (2) defining as a first pressure the end of the pressure of the speed control phase and as a second pressure the pressure of the holding or holding time; (3) defining a linear relationship between the time and the retention pressure / packing consistent with the first pressure and the second pressure, between the first pressure and the second pressure; (4) define the packing time as a time of the maximum difference between the pressure of the measured molten material and the linear relationship, or as the switching point or change if the pressure of the molten material increases after the change or switching point; (5) determining a first displacement of the screw which is the minimum displacement of the screw before the time of packing within a clamping / packing phase and a second displacement of the screw which is the displacement of the screw at the time of packaging; and (6) calculating the return or feedback of the difference between the first and second displacements of the screw, whereby a determination of the return or feedback from the measurements of the displacement of the screw in the packing time is allowed.

18. A method for the automated optimization of a process of equipment of the machine for injection molding, the machine includes an injection screw, characterized in that it includes the steps of: (1) adjusting or establishing an initial clamping / packing pressure to a low pressure of failure; (2) carry out at least one partial injection cycle; (3) determining the return of the changes in the displacement of the screw during the at least one partial injection cycle; (4) increase the initial clamping / packing pressure; and (5) repeating steps (3) and (4) if the return is unacceptably high until the return is reduced to a predetermined acceptable level, or the initial clamping / packing pressure reaches the maximum machine pressure.

19. A method according to claim 18, characterized in that the initial packing / holding pressure is between 5% and 25% of the end of the pressure of the speed control phase, and a substantially uniform packing pressure is used.

20. A method according to claim 19, characterized in that the initial packing / holding pressure is about 10% of the end of the pressure of the speed control phase.

21. A method according to any of claims 18 to 20, characterized in that the initial packing / holding pressure is increased between 2% and 25% of the end of the pressure of the speed control phase.

22. A method according to claim 21, characterized in that the initial packing / holding pressure is increased by about 5% of the end of the pressure of the speed control phase.

23. A method according to any of claims 18 to 22, characterized in that it includes measuring the return or feedback for a plurality of the initial packing / holding pressures, predicting an optimal initial packing / holding pressure from the measurements to minimize the return or feedback, and increase the initial packing / holding pressure to the optimum initial packing / holding pressure.

24. A method for the automated optimization of a process for equipping the machine for injection molding, the machine for manufacturing injection molded parts and including an injection screw, characterized in that it includes the steps of: (1) defining a time of retention equal to a predetermined failure value; (2) carry out at least one partial injection cycle; (3) measure a path or segment of the pressure which is the change in the displacement of the screw between the packing time and the holding time; (4) increase the retention time; (5) repeating steps (3) and (4) until the path or segment of the pressure is stabilized or a part thus produced is acceptable; (6) define a linear relationship between the displacement of the screw and the time consistent with the displacement of the screw in the packing time and the retention time, between the packing time and the retention time; (7) define a time of cooling or freezing of the gate as a time of the maximum difference between the displacement of the screw and the linear relationship, whereby a value for the cooling or freezing time of the gate is provided from the measurements of the displacement of the screw.

25. A method according to claim 24, characterized in that it includes the additional steps of: (8) repeating steps (6) and (7), and defining an initial solidification time between the packing time and the cooling time of the gate; (9) repeating steps (6) and (7), and defining an intermediate solidification time between the packing time and the initial solidification time; and (10) determining an intermediate pressure of the ratio of the screw displacements in the intermediate time and in the cooling or freezing time of the gate, with reference to the packing time.

26. A method according to any of claims 24 or 25, characterized in that the value of the retention time used in step (6) is greater than that defined in step (1) by a factor of between 1 and 3.

27. A method according to any of claims 24 to 26, characterized in that the predetermined failure value is greater than 2 times the injection time and one second.

28. A method according to any of claims 24 to 27, characterized in that the stabilization occurs when the path or segment of the pressure changes in less than a predetermined tolerance between the successive measurements.

29. A method according to any of claims 24 to 28, characterized in that the retention time is increased in step (4) between 5% and 50%.

30. A method according to claim 29, characterized in that the retention time is increased in step (4) by approximately 20%.

31. A method according to any of claims 24 or 30, characterized in that the predetermined tolerance is between 2% and 10%.

32. A method according to claim 31, characterized in that the predetermined tolerance is about 5%.

33. A method for the automated optimization of a process of equipping a machine for injection molding, the machine for manufacturing injection molded parts and including an injection screw and a configurable injection speed, characterized in that it includes the steps of: 1) determine an optimum filling that includes: (i) manufacturing one or more parts with the machine: (ii) inspecting the parts for defects; (iii) reducing the path or segment of injection in response to the formation of burrs or increasing the path or segment of the injection in response to light weights of the material introduced into the mold; and (iv) reducing the speed of the injection in response to burr formation or increasing the injection speed in response to light weights of the material introduced into the mold, wherein any step (iv) is employed after the step ( iii) if step (iii) is found to have substantially no effect or substantially no additional effect, or step (iii) is employed after step (iv) if step (iv) is found to have substantially no effect or substantially does not have an additional effect, whereby the defects are reduced; (2) determine an optimum injection velocity profile, which includes: (i) manufacturing one or more parts with the machine; (ii) determining a profile of the injection pressure by measuring the injection pressure as a function of the injection time elapsed with the machine configured with a desired, substantially constant injection speed; (iii) measuring the speed of the injection as a function of the elapsed injection time and determining a profile of the measured injection velocity; (iv) defining a profile of the average pressure from the pressure profile in a regime of the velocity profile of the injection measured substantially constant; (v) adjusting the speed profile over at least a portion of a phase of the injection velocity in response to the pressure profile to reduce the differences between the pressure profile and the average pressure profile, thereby it tends to reduce irregularities in the pressure profile. (3) modify an equipment or intermediate facility of the post-velocity control phase obtained after steps (1) and (2) in response to the quality defects detected in said manufactured parts with the adjustment or intermediate equipment, to reduce defects; (4) a method of reducing the return to an acceptable level to determine a critical clamping / packing pressure, which includes: (i) adjusting an initial retention / packing pressure to a low failure pressure; (ii) carry out at least one partial injection cycle; (iii) determining the return of the changes in the displacement of the screw during at least the partial injection cycle; (iv) increase the initial packing / holding pressure; and (v) repeating steps (iii) and (iv) if the return is unacceptably large until the return is reduced to a predetermined acceptable level, or the initial holding / packing pressure reaches the maximum machine pressure. (5) deduct the solidification time of the material from the screw displacement measurements to determine an optimum retention / packing pressure profile, which includes: (i) defining a retention time equal to a predetermined failure value; (ii) carry out at least one partial injection cycle; (iii) measuring a path or segment of the pressure which is the change in the displacement of the screw between the packing time and the holding time; (iv) increase the retention time; (v) repeating steps (iii) and (iv) until the path or segment of the pressure is stabilized or a part thus produced is acceptable; (vi) define a linear relationship between the displacement of the screw and the time consistent with the displacement of the screw in the packing time and in the retention time, between the packing time and the retention time; (vii) define a time of cooling or freezing of the gate as a time of the maximum difference between the displacement of the screw and the linear relationship, whereby a value for the freezing time of the gate is provided from the measurements of the displacement of the screw; (6) modify a preliminary equipment of a post-pressure control phase obtained after (1) to (5) in response to the defects detected in the parts manufactured with said adjustment or preliminary equipment to reduce the defects.

34. A method according to claim 33, characterized in that step (iii) of step (4) includes determining the return of the measurements of the displacement of the screw at the time of packaging, characterized in that it includes the steps of: (a) manufacturing a or more parts with the machine; (b) defining as a first pressure the end of the pressure of the speed control phase and as a second pressure the pressure of the retention time; (c) defining a linear relationship between the holding / packing pressure and the time consistent with the first pressure and the second pressure, between the first pressure and the second pressure; (d) defining the packing time as a time of the maximum difference between the pressure of the measured molten material and the linear relationship, or as the switching point or change if the pressure of the measured molten material increases after the switching point or change; (e) determining a first displacement of the screw which is the minimum displacement of the screw before the time of packing within the retention / packing phase and a second displacement of the screw which is the displacement of the screw at the time of packaging; and (f) calculating the return from the difference between the first and second displacements of the screw, whereby a determination of the return from measurements of the displacement of the screw in the packing time is allowed.

35. A method according to any of claims 33 or 34, characterized in that step (5) includes the additional steps of: (viii) repeating steps (vi) and (vii), and defining an initial solidification time between time of packing and freezing time of the gate; (ix) repeating steps (vi) and vii), and defining an intermediate solidification time between the packing time and the initial solidification time; and (x) determining an intermediate pressure from the ratio of the screw displacements in the intermediate time and in the freezing time of the gate, with reference to the packing time.

36. A method according to any of the preceding claims, characterized in that it includes: determining the response time of the speed control of the machine, and employing the time steps equal to, or greater than, the time of the response.

37. A method according to claim 36, characterized in that the time steps are greater than 1.5 times the response time, and more preferably equal to 2 times the response time.

38. A method according to any of the preceding claims, characterized in that the pressure of the molten material in the nozzle, the hydraulic pressure of the injection cylinder, the forward propulsion force applied to the screw, or any other measure proportional to or equal to the pressure of the molten material in the nozzle, is used as a measure of, instead of, or to determine, the injection pressure.

39. A method according to claim 38, characterized in that the hydraulic pressure of the injection cylinder is used as a measure of, or to determine, the injection pressure.