System for feeding multiple materials to forming machines according to a defined formulation

Abstract

System (100) for feeding multiple materials (101-104) to a forming machine (106-108) according to a defined formulation, wherein the system (100) comprises: a distributor (134) forming a mixing chamber (131-133); multiple material feed units (111-114) coupled to the distributor (134), each of the multiple material feed units (111-114) being configured to contain materials (101-104) that are each different from the others in the multiple material feed units (111-114), the multiple material feed units (111-114) comprising at least a first material feed unit (111) containing a first material (101) and a second material feed unit (112) containing a second material (102); a first line (211) connecting the first material feed unit (111) to the distributor (134) connects; a second line (212) that connects the second material supply unit (112) to the distributor (134);a first valve (161) configured to alternately open and close the mixing chamber (131-133) to the first line (211); a second valve (162) configured to alternately open and close the mixing chamber (131-133) to the second line (212); and a control (146) configured to actuate the first valve (161) and the second valve (162) to admit at least one of the first material (101) and the second material (102) into the mixing chamber (131-133) according to the defined formulation; wherein the distributor (134) defines a vent opening (205) and includes a third valve (165) configured to alternately open and close the vent opening (205);and wherein the control (146) is designed to check whether there is a fault in at least one of the two valves, the first and the second valve (161, 162), and is configured to open the third valve (165) in the event of a fault.

Description

The present disclosure relates in general to systems for the automatic formulation of molding materials and in particular to the automatic selection, mixing and feeding of several components to an injection molding machine, formulated for the product to be molded. Injection molding is one of the most common methods for manufacturing products. A specific product is typically made from a particular raw material that is fed into an injection molding machine. Each product may require a specific raw material formula, which can be supplied in solid form for melting, injection, and forming into a mold. When an injection molding machine is changed to a different product, a differently formulated raw material may be required. Preparing the starting material may involve formulating (recipeing) a homogeneous mixture of various powdered, granulated, or pelletized components. To ensure that the molded part has the desired material properties, it may be necessary to follow the formulation precisely and thoroughly mix the components of the starting material.A lack of homogeneity can lead to undesirable properties and / or inclusions. In certain applications, the formulation may contain multiple components. The materials can be manufactured in a variety of forms and may contain all or some of the aforementioned components, as well as other ingredients. The raw material, formulated to meet the requirements of the specific product, is placed in the feed hopper of the injection molding machine. Operating an injection molding machine involves metering an appropriate quantity of the formulated material from the feed hopper into a cylinder for injection into the mold via a piston or screw system. Preparing the correct material formulation for a particular product can also be a manual process, involving mixing the formulation and manually filling a container or hopper with the correct material mixture. DE 2411808 A describes a method for producing sandwich-like products or parts comprising a shell or outer layer and an inner region or core. The shell and core consist of different thermoplastic resin compounds and are formed by injection molding two different mixtures or resin compounds using an injection molding machine with a screw-piston or piston-type injection block. The injection molding machine has only a single injection block, to which, according to a program independent of the displacement of the plasticizing agents in the injection block, the quantities of each of the two mixtures necessary for the production of each part of the sandwich are fed sequentially and individually during the plasticizing phase. The mixture for forming the outer part is fed first. DE 10 2010 039 025 A1 describes a plasticizing unit for an injection molding machine, an extruder or the like, comprising a housing cylinder, at least one plasticizing screw rotatably driven therein, a liquid supply device in front of the outlet end of the housing cylinder for introducing a liquid into a plastic material to be plasticized in the plasticizing unit, at least one liquid connection adapter insert in which a liquid supply channel is arranged, at least one receptacle for the liquid connection adapter insert located in the cylinder wall and opening into the screw chamber via an access bore, a valve arrangement mounted on the liquid connection adapter insert by means of which the liquid supply channel in the area of ​​the adapter insert can be closed, and at least one liquid supply device.which has a liquid pump with a liquid reservoir and is connected to a liquid connection line of the valve assembly. US 5,282,548 A describes a device for automatically selecting a color granulate from various colors and automatically feeding it to an injection molding machine, comprising: an auxiliary hopper connected to a granulate storage area of ​​the injection molding machine via an automatic switching valve; a vacuum device that causes the auxiliary hopper to be under vacuum on the upstream side; a granulate feed line connected to the upstream side of the auxiliary hopper; and storage containers for the respective color granulates, each storage container being connected to the granulate feed line via a respective automatic switching valve. DE 10 2012 210 606 A1 describes an injection molding machine for plastic containers, in particular preforms for bottles, comprising at least one injection molding carousel with at least one injection molding unit, wherein the injection molding unit has at least one one-piece or multi-piece tool for forming at least one mold cavity, at least one storage and metering unit for storing and supplying injection material to an injection molding unit, and wherein the injection molding unit has at least one extruder for supplying plasticized injection material to a mold cavity, characterized in that the extruder is not arranged parallel, preferably perpendicular, to the working plane or plane of rotation of the injection molding carousel. Accordingly, the object of the present invention is to provide systems that efficiently and promptly supply the correct material to the molding machines. The problem is solved by the subject matter of the independent claim. Furthermore, other desirable features and properties of the present invention will become apparent from the following detailed description and the attached claims in conjunction with the attached figures and the preceding introduction. According to the invention, a system is provided for supplying multiple materials to several molding machines according to specific formulations. The material supply units each contain a specific material and are connected to a series of distributors, each of which has a mixing chamber. Pipes connect the material supply units to the distributors. A control unit is configured to actuate valves to direct selected materials from the material supply units into the mixing chamber according to the specified formulations and to supply the mixed materials to the molding machines. The distributor defines a vent opening, and an additional valve is configured to alternately open and close the vent opening.The control system is designed to check if there is a fault in at least one of the other valves and is configured to open the additional valve in case of a fault. In further embodiments, the mixing chamber is configured to mix the first material with the second material. In other embodiments, the distributor defines an outlet. A vacuum system is connected to the outlet and configured to draw in the materials through the outlet. In further embodiments, the distributor comprises a section with a pair of lines connected to the distributor at that section. The distributor includes a further section located below the first section, which tapers and is configured for mixing the materials. In further embodiments, the valves comprise discs configured to close the lines from the mixing chamber, and each valve comprises an actuator with a rod attached to the respective disc, the rod extending over the mixing chamber when the respective valve is closed. In further embodiments, the formulation is carried / specified by a label on the forming machine. A reading device is configured to transmit the formulation from the label to the control system. In further embodiments, the distributor comprises several inlets corresponding to the multiple material supply units and a single outlet, which is the only outlet of the distributor. In further embodiments, several forming machines are included, each of the several forming machines being configured to receive the materials from the several material supply units. In further embodiments, the mixing chamber includes a section that tapers and is designed to mix the first material with the second material. In further embodiments, the distributor defines a vent opening located above the pipes, and an additional valve is configured to alternately open and close the vent opening. In other embodiments, the control system is configured to open the additional valve to prevent all materials from entering the mixing chamber if one of the other valves is defective. In further embodiments, the distributor defines an outlet located below the pipes. A vacuum system is connected to the outlet. The vacuum system is configured to draw the materials from the pipes and through the outlet. In further embodiments, the distributor comprises a section in the shape of a cuboid, with the lines in this section being connected to the distributor. Another section of the distributor is located below this section and is provided with a tapered section for mixing the materials. In further embodiments, the valves each comprise a disc configured to close the lines from the mixing chamber, and each includes an actuator located on the side of the manifold opposite the lines. The actuators each comprise a rod attached to their respective disc. Each rod extends transversely through the mixing chamber to its respective disc. In further embodiments, a die is inserted into the molding machine. The formulation is located on a label attached to the die. A reading device is configured to read the label and transmit the formulation information from the label to the control system. In further embodiments, the distributor comprises several inlets corresponding to the multiple material feed units and one outlet, which is the distributor's sole outlet. A vacuum system is connected to the outlet to draw one or more of the materials into the mixing chamber. The exemplary embodiments are described below in conjunction with the following figures, where identical numbers denote identical elements and where: Fig. 1 is a schematic representation of a system for the automatic formulation and delivery of materials to molding machines, in accordance with various embodiments; Fig. 2 is a perspective view of a mixing chamber distributor of the system of Fig. 1 in accordance with various embodiments; Fig. 3 is a schematic representation of the mixing chamber distributor of Fig. 2 in a closed state, according to various embodiments; and Fig. 4 is a schematic representation of selected parts of the system of Fig. 1, including the mixing chamber distributor of Fig. 2, in a feeding state according to various embodiments. With reference to Fig. 1, a system 100 for the automatic formulation and delivery of materials 101-104 to injection molding machines 106-108 is shown. Although the system 100 is depicted as delivering materials 101-104 to injection molding machines 106-108, it is not limited to feeding a specific type of machine. Rather, it can be used for material delivery in any application where selection from multiple materials is required to meet a formulation that necessitates mixing and delivery. In other embodiments, the system 100 can be configured to deliver any number of materials, such as one or more materials, and is therefore not limited to the four materials 101-104.Furthermore, the System 100 is not limited to operating three machines, such as the injection molding machines 106-108, but can be configured to operate any number of machines or other equipment that require the supply of materials, such as materials 101-104. As shown in Fig. 1, the materials 101-104 supplied to the injection molding machines 106-108 are contained in four material feed units 111-114. Each of the four materials 101-104 differs from the others. For example, the materials 101-104 may contain several polymers, binders, hardeners, and / or other materials required for the formulation of the product molding compound. The materials 101-104 may be solids in powder, granule, pellet, or other form, contained as bulk material in the material feed units 111-114. The material feed units 111-114 are loaded with the materials 101-104 and can be configured to maintain these materials 101-104 under the desired conditions.In the present embodiment, the material feed units are configured as dehumidifiers that can dry the materials 101-104 and / or maintain the moisture content of the materials 101-104 within a preferred range. The moisture content can be controlled so that the materials 101-104 are conveyed properly and undesirable effects of moisture evaporation in the injection molding machines 106-108 are avoided. In other embodiments, the materials 101-104 can be contained in a different form of material feed units 111-114, which can be configured as dryers, containers, bags, or other receptacles. System 100 includes a formulation system 120, which is connected between the material feed units 111-114 and the injection molding machines 106-108. Formulation system 120 comprises three formulation units 121-123. The formulation units 121-123 are arranged to receive all materials 101-104 and to feed mixtures of selected materials 101-104 to the injection molding machines 106-108. The current embodiment includes three formulation units 121-123, one of which is intended for each of the injection molding machines 106-108. In other embodiments, one of the formulation units 121-123 can supply several of the injection molding machines 106-108. In further embodiments, several of the formulation units 121-123 can supply one of the injection molding machines 106-108.In general, the formulation units 121-123 receive some or all of the materials 101-104, depending on the formulation for the part to be molded, mix the materials 101-104 received and deliver them to the respective injection molding machine 106-108. Each of the formulation units 121-123 includes a corresponding mixing chamber 131-133 configured to mix the received materials 101-104. Each of the formulation units 121-123 also includes a corresponding material control system 141-143 that controls which of the materials 101-104 are received by the formulation units 121-123. For example, the material control systems 141-143 can control which of the materials 101-104 is admitted into each of the mixing chambers 131-133. The formulation system 120 also includes a control system 144, including a control unit 146. The control unit 146 can be an industrial programmable logic controller or any programmable control unit with a processor 148 and a memory 150 and / or a storage device 152 for executing programmed instructions and generating control signals.The controller 146 can be programmed or supplied with data about the type of materials 101-104 contained in the material feed units 111-114, e.g., by manual input. An interface 154 connects the controller 146 to the material control systems 141-143. The interface can be an electrical bus, a pneumatic control system, a hydraulic control system, a mechanical system, or a combination thereof. Each of the material control systems 141-143 comprises a set of four actuated valves, one of which corresponds to each of the materials 101-104. For example, material control system 141 comprises valves 161-164 and corresponding actuators 171-174 for actuating these valves 161-164. The actuators 171-174 move the valves 161-164 in response to the control system 144. For example, the control system 146, as communicated via the interface 154, can command one of the valves 161-164 to open in order to feed the respective material(s) 101-104 through the formulation system 120 of the injection molding machine 106. The valve(s) 161-164 that is / are opened supplies / supply those of the materials 101-104 that correspond to the formulation intended for the product produced in a tool 158 in the injection molding machine 106.The injection molding machines 106-108 are configured to produce any number of different parts, each of which is formed in a mold 156-158 specifically designed for that part and containing cavities corresponding to the shape of the parts to be formed. It is evident that in embodiments, each of the individual dies 156-158 can have cavities shaped to produce multiple part shapes if these multiple shapes have the same material composition. The controller 146 can be coupled to the injection molding machines 106-108 to receive the formulations for the molds 156-158. The formulations can be automatically supplied to the controller 146 when the molds 156-158 are loaded into the respective injection molding machine 106-108, for example, by means of a detected label. B. an RFID label, or they can be entered manually or supplied to the control 146 in other ways. Figure 2 shows aspects of the formulation unit 121, and in particular the area of ​​the mixing chamber 131, as an example for the formulation units 121-123 and the mixing chambers 131-133, which can be essentially identical. The mixing chamber 131 is formed by a distributor 134, which includes a section 180 in the form of a rectangular cuboid, a section 182 in the form of a cylinder, and a section 184, which forms a transition from section 180 to section 182. The section 184 is tapered and shaped to transition from a square to a circular shape. The sections 180, 182, and 184 form a housing in the form of the distributor 134, which defines the mixing chamber 131 as a hollow, enclosed space through which the materials 101-104 can flow when introduced.Section 180 is elongated in the vertical direction and comprises a top 188, a bottom 190, a front 192, a back 194, an inlet side 196, and a control side 198. The top 188, the front 192, and the back 194 are closed and may consist of flat plates. The bottom 190 is open to section 184 and through it to section 182 and the injection molding machine 106. The inlet side 196 has couplings 201-204 as inlets, corresponding to the number of material feed units 111-114, and also includes an open vent 205. The control side 198 comprises five actuators, including actuators 171-174 and an actuator 175, which is aligned with the vent 205. The actuators 171-175 are coupled to the interface 154. One embodiment of the formulation unit 121 is shown schematically in Fig. 3, to which reference is made. The material feed units 111-114 are connected to the distributor 134 at the couplings 201-204 by lines 211-214. The lines 211-214 are suitable for transporting the materials 101-104 and, in the present embodiment, can be hoses or pipes. The diameter of the lines 211-214 can be selected to calibrate the flow rate of the materials 101-104 conveyed by them. The valves 161-164 are oriented such that they normally close the lines 211-214 at the inlet side 196 of the distributor 134. In the present embodiment, the valves 161-164 are equipped with discs 221-224, which are arranged in the mixing chamber 131 and close the lines 211-214 when they contact the couplings 201-204 at the inlet side 196. Each of the discs 221-224 is connected to a corresponding rod 225-228, each of which is part of one of the actuators 171-174. The actuators 171-174 are mounted on the control side 198 of the distributor 134, and their rods 225-228 extend through the interior of the mixing chamber 131, across the distributor, and to the inlet side 196. A valve 165 is arranged for actuating the vent 205 and is located in a normally closed position opposite the inlet side 196. The valve 165 includes a disc 232, which is connected to a rod 234 of the actuator 175. In the present embodiment, the actuators 171-175 are pneumatic cylinders operated by the control unit 146 via the interface 154, which includes a pneumatic regulator. The interface 154 may, for example, have valves that control the operating pressure supplied to the actuators 171-175. In other embodiments, the actuators 171-175 may, for example, be electrically or hydraulically operated. The actuators 171-175 may be single-acting, operating under pneumatic pressure to open the valves 161-165 and returning to close them under spring force, or they may be double-acting, operating under pneumatic pressure to both open and close the valves 161-165. Figure 4 schematically shows the formulation unit 121 in system 100 as it feeds material to the injection molding machine 106. The formulation unit 121 is connected via a line 238 to a vacuum system 240, which includes a blower 242 and an outlet 244. The blower 242 creates a negative pressure in the line 238, which in turn creates a vacuum in the mixing chamber 131. The outlet 244 of the vacuum system 240 is arranged such that the mixed and conveyed material 246 falls into a hopper 248 of the injection molding machine 106. In one example, the product formed by the die 156 requires a formulation of material 246 containing material 101, material 103, and material 104. This formulation is transmitted to the controller 146. For example, the tool 156 may carry a label 252 containing the formulation, and the injection molding machine 106 may include a reader 254 arranged to read the label 252 when the tool 156 is loaded into the injection molding machine 106. The reader 254 is configured to transmit the formulation to the controller 146. In one embodiment, the formulation is transmitted via a wire connection. In other embodiments, the formulation can be transmitted wirelessly. According to the communicated wording, the controller 146 actuates the actuators 171, 173, and 174 to open the valves 161, 163, and 164. The discs 221, 223, and 224 are pulled away from the inlet side 196 and open the lines 211, 213, and 214 to the mixing chamber 131. The valves 162 and 165 remain closed. As a result, the vacuum system 240 draws the materials 101, 103, and 104 into the mixing chamber 131. The material 102 is not conveyed into the mixing chamber 131. The three materials 101, 103, and 104 migrate downwards towards the bottom 190 of section 180 and into section 184. The tapered, conical shape of section 184 generates a swirl 250, which contributes to the mixing of materials 101, 103, and 104. The mixed material 246 flows through section 182 and line 238 to the vacuum system 240 and is deposited in hopper 248.The conveyance through line 238 and vacuum system 240 also contributes to mixing materials 101, 103, 104 to form material 246. The formulation unit 121 can be calibrated to deliver a material flow 246 that corresponds to the consumption rate of the injection molding machine 106. In other embodiments, the formulation unit 121 and / or the vacuum system 240 can operate on an intermittent schedule to supply the injection molding machine 106 as needed. When the mold 156 is changed, the valves 161-164 can be closed and the valve 165 opened while the vacuum system 240 is operating to clean the mixing chamber 131 and the line 238 of the previous material 246. If an error in the formulation is detected, the controller 146 commands the actuator 175 to open the valve 165. This introduces atmospheric pressure, releases the vacuum in the mixing chamber 131, and stops the material flow, even if other valves 161-164 remain open. The actuators 171-174 can, for example, provide feedback to the controller 146 about their position status. If one of the positions does not match the formulation, the controller 146 can interrupt the material flow by opening the valve 165 until the error is corrected. Accordingly, a system selects the raw material, mixes it, and delivers it to the molding machines according to a defined formulation of the part to be manufactured. Efficient and automatic material changes can be carried out with reduced potential for errors.

Claims

System (100) for feeding multiple materials (101-104) to a forming machine (106-108) according to a defined formulation, wherein the system (100) comprises: a distributor (134) forming a mixing chamber (131-133); multiple material feed units (111-114) coupled to the distributor (134), each of the multiple material feed units (111-114) being configured to contain materials (101-104) that are each different from the others in the multiple material feed units (111-114), the multiple material feed units (111-114) comprising at least a first material feed unit (111) containing a first material (101) and a second material feed unit (112) containing a second material (102); a first line (211) connecting the first material feed unit (111) to the distributor (134) connects; a second line (212) that connects the second material supply unit (112) to the distributor (134);a first valve (161) configured to alternately open and close the mixing chamber (131-133) to the first line (211); a second valve (162) configured to alternately open and close the mixing chamber (131-133) to the second line (212); and a control (146) configured to actuate the first valve (161) and the second valve (162) to admit at least one of the first material (101) and the second material (102) into the mixing chamber (131-133) according to the defined formulation; wherein the distributor (134) defines a vent opening (205) and includes a third valve (165) configured to alternately open and close the vent opening (205);and wherein the control (146) is designed to check whether there is a fault in at least one of the two valves, the first and the second valve (161, 162), and is configured to open the third valve (165) in the event of a fault. System according to claim 1, wherein the mixing chamber (131-133) is configured to mix the first material (101) with the second material (102). System according to claim 1, wherein the distributor (134) defines an outlet (244) and comprises a vacuum system (240) coupled to the outlet (244), wherein the vacuum system (240) is configured to draw the first material (101) and the second material (102) through the outlet (244). System according to claim 1, wherein the distributor (134) comprises: a first section (180), wherein the first line (211) and the second line (212) are connected to the distributor (134) at the first section (180); and a second section (182) arranged below the first section (180), wherein the second section (182) is formed with a taper (184) which serves to mix the first material (101) with the second material (102). System according to claim 1, wherein the first valve (161) comprises a disk (221) configured to close the first line (211) from the mixing chamber (131), and comprises an actuator (171) with a rod (225) attached to the disk (221), wherein the rod (225) extends over the mixing chamber (131) when the first valve (161) is closed. System according to claim 1, wherein the formulation is carried by a label (252) on the forming machine (106-108) and the system comprises a reading device (254) configured to deliver the formulation from the label (252) to the control (146). System according to claim 1, wherein the distributor (134) has multiple inlets (201-204) corresponding to the multiple material supply units (111-114) and an outlet (244) which is the only outlet (244) of the distributor (134). The system according to claim 1 comprises several forming machines (106-108), each of the several forming machines (106-108) being configured to receive the materials (101-104) from the several material supply units (111-114).

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