Apparatus and method for manufacturing objects from plastic materials in a continuous cycle.

Abstract

An apparatus (1) for manufacturing objects in a continuous cycle from a plastic material, comprising a dispensing unit (2), a forming station (4) for forming a plurality of objects by compression molding, a metering unit (3) having an outlet valve system that is switchable between an open configuration and a closed configuration, a plurality of partition elements upstream of the outlet valve system, the plurality of partition elements being movable between an upper limit position (X1) and a lower limit position (X2) to change the internal volume of the dispensing unit (2), and a group of actuators for moving the plurality of partition elements between the upper limit position (X1) and the lower limit position (X2), the metering unit (3) being provided with an outlet valve system (302) in a closed configuration in the filling configuration of the metering unit (3) and an outlet valve system (302) in an open configuration in the filling configuration, the apparatus (1) comprising a control unit (5) for switching the metering unit (3) from a filling configuration to a discharging configuration and from a discharging configuration to a filling configuration and driving a group of actuators to move the corresponding partition elements.

Description

[Technical Field]

[0001] The present invention relates to an apparatus and a method for manufacturing objects from plastic materials in continuous cycles.

[0002] The present disclosure relates to the field of molding objects from thermoplastic materials. More specifically, the field relates to the field of simultaneously molding a plurality of objects from plastic materials. In an exemplary embodiment, the object is a parison intended to form a container by subsequent blow molding. [Background Art]

[0003] In the prior art for this purpose, there is known an apparatus in which a metering unit is configured to form a plurality of measured plastic doses from a flow of molten plastic. An example of this type of apparatus is described in JP2017177455A, wherein rotating elements are configured to rotate together to divide the flow of molten plastic into a plurality of identical doses. However, this type of apparatus does not allow for the accurate formation of doses, nor does it allow adjustment of the amount of plastic in one dose independently of the amount of another dose. In this regard, as described, for example, in JPH06114867A, apparatuses including a system for measuring and adjusting the amount of material to adjust the amount of plastic in each dose are known in the prior art. This document describes a plastic distributor provided with a plurality of outlet ports, each outlet port being provided with a metering and injection unit configured to measure and adjust the amount of material forming a dose. However, this document does not sufficiently describe in detail the method of measuring and adjusting material to form doses.

[0004] Patent document US5858420 describes a solution relating to an injection molding system in which a continuous flow of plastic is divided and distributed, and the injected plastic is measured by a volumetric system. [Summary of Invention]

[0005] This disclosure aims to provide an apparatus and method for manufacturing objects from thermoplastic materials in a continuous cycle in order to overcome the aforementioned shortcomings of the prior art.

[0006] More specifically, the object of this invention is to provide an apparatus and method for manufacturing an object from a plastic material in a continuous cycle, the apparatus and method capable of uniformly dividing a continuous flow of plastic material into multiple doses.

[0007] Another object of this invention is to propose an apparatus and method for manufacturing an object from a plastic material in a continuous cycle, such that the amount of one dose of plastic can be adjusted independently of other doses.

[0008] Another object of this disclosure is to provide an apparatus and method for manufacturing an object from a plastic material in a continuous cycle, wherein multiple doses are available, and the volume of each dose is precisely known.

[0009] These objectives are fully achieved by the apparatus and method of this disclosure for manufacturing objects from plastic materials in a continuous cycle, as characterized in the attached claims.

[0010] This disclosure relates to an apparatus for manufacturing objects from plastic materials in a continuous cycle. The plastic materials may be, for example, HDPE, PET, or PP. HDPE plastic materials may have a melt index (or melt flow index) of 0.2 to 3 g / 10 min (at 190°, 2.16 kg, ASTM D1238). HDPE plastic materials may have a melt index of 0.940 to 0.970 g / cm³. 3HDPE plastic materials may have a density of . HDPE plastic materials may have a monomodal or bimodal molecular weight distribution. HDPE plastic materials may contain nucleating agents (e.g., macromolecules that are more linear compared to chromium catalytic processes and do not branch by Ziegler-Natta catalysts or metallocene catalysts). HDPE plastic materials may contain additives that increase oxygen and / or moisture barrier properties by 20% to 50%. PET plastic materials may have an intrinsic viscosity of 0.72 to 1.10 dl / g (ASTM D4603-03). PP plastic materials may have a melt index between 0.5 and 4 g / 10 min (at 230°C, 2.16 kg, ISO 1133). PP plastic materials may have a flexural modulus between 850 and 2000 MPa. PP materials may be homopolymers, random copolymers, or block copolymers.

[0011] The apparatus includes a distribution unit. The distribution unit is configured to distribute plastic to the apparatus or to a part of the apparatus. The distribution unit includes a supply duct having an inlet. The inlet may be configured to receive a continuous flow of molten plastic, for example, from an extrusion unit. The extrusion unit may be configured to receive the plastic in its raw form and discharge a flow of molten plastic. The outlet of the extrusion unit may be located in the supply duct of the metering unit. For example, the flow of molten plastic received by the supply duct (i.e., by the inlet of the supply duct) may be pressurized. In one example, the distribution unit includes a plurality of dispensing branches. Each of the multiple dispensing branches, more precisely, each dispensing branch of the plurality of dispensing branches, is in fluid communication with the supply duct, for example, via a distribution zone. The distribution zone is preferably configured to communicate with each dispensing branch, the inlet, i.e., the supply duct, so that the plastic is supplied to and distributed toward the dispensing branches, i.e., divided between the dispensing branches. In other words, the distribution zone is configured to divide the flow of plastic into a plurality of (separate) flows of plastic.

[0012] Each of the multiple supply branches preferably has an outlet, thus defining a corresponding number of outlets. The distribution unit defines the internal volume between the inlet and outlet, i.e., between the supply duct and the multiple supply branches.

[0013] The distribution zone may be a single distribution zone or may include multiple distribution zones. In one example, multiple distribution zones may include a first distribution zone and a second distribution zone. The first distribution zone, located downstream of the supply duct in the direction of plastic supply from inlet to outlet, may be configured to divide the plastic flow into multiple (separate) flows of plastic, and the second distribution zone, located downstream of the first distribution zone, may be configured to receive the multiple separate flows of plastic and further divide them.

[0014] In this example, the first and second distribution zones constitute the first and second branches for the inflow of a continuous flow of plastic toward the supply duct.

[0015] The apparatus includes a forming station. The forming station may be an injection molding station, or an injection compression molding station, or more preferably a compression molding station. The forming station is configured to form multiple plastic objects from multiple predetermined amounts of plastic, i.e., doses of plastic. The forming station includes multiple female elements, i.e., multiple lower molds, and multiple male elements, i.e., multiple upper molds. Preferably, the multiple female elements can be arranged in multiple dispensing branches of a distribution unit, i.e., each female element can be placed in an individual dispensing branch. Thus, each female element is configured to receive plastic from the outlet of an individual dispensing branch. Preferably, the multiple female elements define a plurality of corresponding sheets, each sheet is configured to receive a predetermined amount of plastic, i.e., a dose.

[0016] Preferably, each of the multiple sheets has a receiving diameter, and the diameter of one dose of the multiple doses is smaller than the receiving diameter of each of the multiple sheets.

[0017] Preferably, the receiving diameter of the sheet is proportional to the shape of the plastic object and / or depends on the polymer properties of the plastic material (HDPE, PP, or PET). In one example, the difference between the receiving diameter of the sheet and the diameter of the volume is between 1 mm and 10 mm. Preferably, each of the multiple sheets has a receiving height, and the height of one volume is less than or equal to the receiving height of the individual sheets. Multiple male elements are configured to cooperate with each corresponding female element of the multiple female elements to define the corresponding multiple forming cavities. Multiple male elements preferably cooperate with each corresponding female element of the multiple female elements to form multiple objects from the plastic material by compression molding. In one example, the objects are parisons intended to form a container by blow molding.

[0018] If the object is a parison and the plastic material is HDPE, the parison may have an axial stretchability between 1 and 1.5, preferably between 1 and 1.3. The axial stretchability is equal to the ratio of the height of the container to the height of the parison. The parison may have a radial stretchability between 1.2 and 5, preferably between 1.2 and 3. The radial stretchability is equal to the ratio of the diameter of the container to the diameter of the parison. The parison may stretch between 0.2 m / s and 2.5 m / s, preferably between 0.5 m / s and 1.5 m / s.

[0019] If the object is a parison and the plastic material is PP or PET, the parison may have an axial stretchability between 1 and 4, preferably between 1 and 3. The axial stretchability is equal to the ratio between the height of the container and the height of the parison. The parison may have a radial stretchability between 1 and 5, preferably between 1.2 and 4. The radial stretchability is equal to the ratio between the diameter of the container and the diameter of the parison. The parison may stretch between 0.2 m / s and 2.5 m / s, preferably between 0.5 m / s and 1.5 m / s.

[0020] The apparatus may form part of a continuous cycle production line for containers (for example, for liquids or other purposes). The container production line may further include a station for blow molding parisons to form the containers. In one example, the apparatus includes a forming station made in accordance with the patent document IT102021000032507 in the name of the present applicant, which is incorporated herein by reference. The apparatus may also include a blow molding station made in accordance with the patent document IT102021000032507, which is incorporated herein by reference.

[0021] This device includes a weighing unit. The weighing unit is configured to measure a predetermined amount of plastic, that is, to form a predetermined amount of plastic in a predetermined quantity from a continuous flow. Preferably, the weighing unit is configured to form multiple quantities of plastic simultaneously.

[0022] In one example, the metering unit includes an outlet valve system. The outlet valve system is configured to block, i.e., separate, the plastic between, for example, an upstream zone and a downstream zone of the outlet valve system, with respect to the direction of plastic supply from inlet to outlet. Preferably, the outlet valve system comprises a plurality of outlet valves. Each of the plurality of outlet valves may be located in an individual dispensing branch. The outlet valve system can be switched between an open configuration and a closed configuration. For this purpose, the outlet valve system may comprise a plurality of valves, shutters, or circuit breakers. For example, in the closed configuration of the outlet valve system, the outlet valve system is configured to block the flow of plastic discharged, for example, from a distribution unit. For example, in the open configuration of the outlet valve system, the outlet valve system is configured to allow plastic to be discharged from the internal volume of the distribution unit. In this way, when transitioning from the open to the closed configuration of the outlet valve, the metering unit is configured to form a plurality of doses discharged from the corresponding plurality of dispensing branches of the distribution unit.

[0023] Preferably, the weighing unit comprises a plurality of partition elements or separating walls. The plurality of partition elements may be movable between an upper position and a lower position, for example, to change the internal volume of the dispensing unit, i.e., to change the amount of plastic that can be contained within the dispensing unit.

[0024] Preferably, the metering unit includes one or more operating configurations, i.e., is operable with one or more operating configurations. For example, the metering unit has a filling configuration in which the outlet valve system is in a closed configuration. For example, the metering unit has a discharge configuration in which the outlet valve system is in an open configuration.

[0025] This device may include a control unit configured to switch the metering unit from a filling configuration to a discharge configuration, and vice versa.

[0026] In one embodiment, the metering unit includes an additional valve system. The additional valve system is preferably configured to separate, i.e., block, the flow of plastic from, for example, an upstream zone to a downstream zone. The additional valve system can be switched between an open configuration and a closed configuration. For this purpose, the additional valve system may comprise a plurality of valves, shutters, or circuit breakers. For example, when the metering unit is in a filling configuration, the additional valve system is in an open configuration. When the metering unit is in a discharge configuration, the additional valve system is in a closed configuration. Preferably, the additional valve system is located upstream of the outlet valve system. In this way, the outlet valve system is configured to separate, i.e., block, the plastic between a downstream zone of the additional valve system and a downstream zone of the outlet valve system.

[0027] The internal volume includes an actuation portion located between an outlet valve system and an additional valve system. In other words, the portion of the internal volume between the outlet valve system and the additional valve system constitutes the actuation portion of the internal volume. For example, to allow plastic to accumulate in the actuation portion of the internal volume, the outlet valve system can be in a closed configuration and the additional valve system can be in an open configuration. To allow plastic to be discharged from the actuation portion of the internal volume, the outlet valve system can be in an open configuration and the additional valve system can be in a closed configuration.

[0028] In an example including an outlet valve system and an additional valve system, the plurality of partition elements are preferably arranged between the additional valve system and the outlet valve system. Preferably, each of the plurality of partition elements is movable between an upper limit position and a lower limit position to change the actuation portion of the internal volume of the distribution unit. The actuation portion of the internal volume may be variable from a contracted configuration having a minimum volume to an expanded configuration having a maximum volume. More specifically, the difference between the maximum volume and the minimum volume of the actuation portion is equal to the volume of a single dose multiplied by the number of delivery branches.

[0029] In this regard, the metering unit may comprise a filling configuration, in which the metering unit is configured to allow plastic to accumulate, for example, in the actuation portion of the internal volume of the distribution unit. Preferably, in the filling configuration, the outlet valve system is in the closed configuration and the additional valve system is in the open configuration. In this way, plastic can be supplied to the actuation portion of the internal volume. The metering unit may comprise a discharge configuration, in which the metering unit is configured to allow plastic to be discharged from the actuation portion of the internal volume, for example. In the discharge configuration, the metering unit may be configured to allow a dose of plastic formed from a flow of plastic to be discharged through the outlet. Accordingly, in the discharge configuration, the apparatus is configured to supply doses to a plurality of sheets of a plurality of female mold elements. Preferably, in the discharge configuration, the outlet valve system is in the open configuration and the additional valve system is in the closed configuration, so as to allow plastic to be discharged from the actuation portion and a dose to be delivered.

[0030] Preferably, the control unit is configured to switch the metering unit from the discharge configuration to the filling configuration when the plurality of partition elements are arranged at the upper limit position. Preferably, the control unit is configured to switch the metering unit from the filling configuration to the discharge configuration when the plurality of partition elements are arranged at the lower limit position.

[0031] In other words, the additional valve system is configured to separate a predetermined amount of plastic from the continuous flow of plastic and allow the predetermined amount of plastic to advance into the zone between the additional valve system and the outlet valve system, that is, the working portion. In this way, the working portion is configured to be filled with the predetermined amount of plastic to expand its volume, while the plurality of partition elements are configured to move from the lower limit position to the upper limit position. The upper limit position of the partition element is preferably a fixed position, that is, a position beyond which the partition element cannot move, which means that the internal volume (or the working portion of the internal volume) cannot be further expanded during the molding operation.

[0032] In one example, the additional valve system comprises a main valve arranged in the supply duct. In one example, the additional valve system comprises a plurality of valves, and each valve of the plurality of valves is arranged in a corresponding delivery branch of the plurality of delivery branches.

[0033] In examples with an outlet valve system and an additional valve system, it should be noted that when the multiple partition elements of the additional valve system are in the upper limit position, the outlet valve system is configured to separate an additional amount of plastic from a predetermined amount contained in the working part. For this purpose, the outlet valve system is configured to switch to an open configuration, allowing the working part to contract its volume and empty the predetermined amount of plastic it contains, while the multiple partition elements move from the upper limit position to the lower limit position. Thus, the additional predetermined amount of plastic separated by the outlet valve system is equal to the difference between the volume of the working part when the multiple partition elements are in the upper limit position and the volume of the working part when the partition elements are in the lower limit position. More specifically, the additional predetermined amount of plastic defines the volume of each dose of plastic. Therefore, the volume of each dose is precisely known.

[0034] In one embodiment, each of the multiple partition elements is positioned at a delivery branch upstream of the corresponding outlet valve. For example, to change the internal volume of the distribution unit, the multiple partition elements are movable from an upper position to a lower position. In embodiments including an additional valve system and multiple partition elements, when the metering unit is in a filling configuration, the outlet valve system is in a closed configuration to block the flow of plastic from the distribution unit, and when the metering unit is in a discharge configuration, for example, the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit. In this regard, moving the multiple partition elements from an upper limit position to a lower limit position when the metering unit is in a discharge configuration, and moving them from a lower limit position to an upper limit position when the metering unit is in a filling configuration, generates multiple doses of plastic to be supplied to multiple sheets. During movement from the lower limit position to the upper limit position, with the outlet valve system in a closed configuration, the plastic advances from the inlet and accumulates in the internal volume. During movement from the upper limit position to the lower limit position, with the outlet valve system in an open configuration, the plastic exits the internal volume. In an example comprising an outlet valve system and multiple partition elements, the single dose, i.e., the amount of plastic that forms the dose supplied to each individual sheet of the multiple sheets, is defined by the amount of plastic contained downstream of the corresponding outlet valve, with the outlet valve in a closed configuration and the corresponding partition element in the lower limit position.

[0035] Compared to embodiments comprising an outlet valve system and additional valve systems, the apparatus comprising an outlet valve system has the advantage of being less complex while maintaining the advantages of precision.

[0036] It should be noted that the outlet valve system and the multiple partition elements constitute separate elements of the device, and they also have two separate functions. That is, the outlet valve system has the function of dividing the continuous flow (or, if additional valve systems are present, it has the function of further dividing the amount of plastic contained in the working part), while the multiple partition elements have the function of supplying a dose from the internal volume (or, if additional valve systems are present, from the working part of the internal volume) toward the outlet.

[0037] If an additional valve system exists, it is also a separate element and has a different function from the multiple partition elements. More specifically, the additional valve system has the function of dividing a continuous flow into doses.

[0038] In one example, the metering unit comprises multiple cutting devices in addition to, or preferably instead of, multiple partition elements, an outlet valve system, and an additional valve system, each cutting device being switchable between an open configuration, where it is located at the outlet and allows the plastic to be discharged from the outlet, and a closed configuration, where in the closed configuration the cutting device is configured to close the outlet and separate the amount of plastic that forms the corresponding dose. Thus, in one example, multiple cutting devices provide an alternative solution to multiple partition elements and valves, in which the plastic is extruded from the dispensing branch and the cutting devices are configured to divide the extruded plastic into portions. The device may also comprise a sensor system including multiple sensors, each of which is configured to detect a flow parameter in real time that correlates with the flow rate of plastic in each dispensing branch, and a control unit may be connected to the sensor system and the multiple cutting devices to drive them according to the flow parameter. Preferably, the flow parameter represents the length of the portion of plastic extruded through each outlet and located outside the distribution unit.

[0039] In one example, each cutting device comprises a first knife and a second knife, each including a first blade and a second blade positioned on either side of the knife in the direction of movement, and the first and second knives are positioned side by side along the direction of movement. The first and second knives may be movable relative to each other to exchange positions between an open position and a closed position as they move from an open position to a further open position. More specifically, in the closed position of the first and second knives, they are configured to work together to cut the dose at the outlet. In this way, each time the position is changed, the first and second knives can quickly separate the dose without obstructing the outlet.

[0040] In one example, at least one of a plurality of partition elements may be movable between a lower limit position and an upper limit position by pressure applied to that at least one partition element by plastic.

[0041] Alternatively, or additionally, the weighing unit may include an actuator for at least one of the partition elements, or one actuator for each section element of the partition elements. In one example, the weighing unit may include a group of actuators, each actuator of the group connected to a corresponding partition element of the partition elements. The actuators may be configured to move the corresponding partition elements between an upper limit position and a lower limit position, preferably continuously. The actuators have the advantage of allowing precise control of the upper and lower limit positions of the partition elements, particularly during the molding process.

[0042] In one example, the control unit may be configured to drive one or more actuators of a group of actuators to move the corresponding partition element from an upper limit position to a lower limit position, preferably when the metering unit is in a discharging configuration. The control unit may also be configured to drive one or more actuators of a group of actuators to move the corresponding partition element from a lower limit position to an upper limit position, preferably when the metering unit is in a filling configuration. In this way, it is possible to form multiple quantities of plastic that can be supplied to multiple sheets.

[0043] In one example, the multiple partition elements include a group of partition elements that include multiple secondary partition elements. Preferably, each partition element of the multiple secondary partition elements is positioned at the corresponding dispensing branch of the multiple dispensing branches. The secondary partition elements positioned at the dispensing branches have the advantage of being able to adjust the amount of plastic dispensed from the outlet of the dispensing branch.

[0044] In one example, the multiple partition elements include a main partition element. Preferably, the main partition element is located within the supply duct of the distribution unit.

[0045] The main partition element placed within the supply duct has the advantage of regulating the flow of plastic and supplying a total amount of plastic consisting of the sum of all doses. This total amount of plastic is then divided among multiple distribution branches by distribution zones to form multiple doses.

[0046] Preferably, the upper or lower limit position of at least one of the multiple partition elements is adjustable to change, for example, the maximum amount of plastic that can be contained in the internal volume or the working part of the internal volume. In this way, for example, if multiple dispensing branches are geometrically different from each other, it is possible to adjust the maximum amount of plastic that can be contained in the internal volume (more precisely, each branch of the multiple branches) or the working part of the internal volume.

[0047] In one example, the outlet valve system comprises multiple pushers. For example, each pusher may be located at a corresponding dispensing branch. Each pusher may be reciprocally movable between a retracted position and multiple forward positions. For example, the retracted position is a position that does not interfere with the flow of plastic in the corresponding dispensing branch. For example, the forward position is a position where the pusher closes the corresponding dispensing branch. Preferably, in the multiple forward positions, the pusher is configured to push out the corresponding dose through the outlet by moving, for example, in the extraction direction between the forward positions. Preferably, in the retracted position, the pusher keeps the corresponding outlet valve of the outlet valve system open. Preferably, in the multiple forward positions, the pusher keeps the corresponding outlet valve of the outlet valve system closed. In this way, while the pusher keeps the corresponding outlet valve closed, the corresponding valve of the additional valve system is configured to be open, allowing the plastic to advance into the working volume portion of the distribution unit. When moving in the extraction direction between the forward positions, the pusher has the advantage of further separating the plastic from the working portion and pushing the dose out of the outlet.

[0048] In one example, the control unit is programmed to control the upper or lower limit position of at least one of a plurality of partition elements for one molding operation in a series of molding operations. Preferably, the control unit is programmed to control the upper or lower limit position based on (i.e., according to) a check parameter. Alternatively, the control unit may be configured to drive one or more actuators according to a check parameter. The check parameter may represent the one molding operation in a series of molding operations, a previous molding operation, or a plurality of previous molding operations. The check parameter may be processed at the end of a cycle for molding a plastic object, for example, outside the apparatus for manufacturing the object, or at the end of a molding operation, or during molding. In one embodiment, the check parameter represents the difference between the volume or mass of a single dose dispensed from a dispensing branch and a reference value for the volume or mass of said dose. The check parameter may be obtained from an optical sensor, a flow sensor, or a gravimetric sensor. The optical sensor may be placed between a plurality of female elements and the outlet of the dispensing branch to measure the amount of plastic dispensed from the outlet of the dispensing branch, for example, by measuring the length of the dispensed dose. A flow sensor may be placed at the outlet branch or inlet to measure the flow rate of plastic discharged from the outlet or fed through the supply duct. In this way, the device is preferably configured to adjust, by feedback, the amount of plastic that forms a predetermined amount, i.e., a check parameter, which determines the dose. A weight sensor may be placed on one of a plurality of sheets to measure the weight of a single dose within that sheet.

[0049] In one example, each female element of a plurality of female elements is movable along a longitudinal axis of movement between a spaced position where it does not interfere with the corresponding male element of the plurality of male elements, and a close position where it acts in conjunction with the corresponding male element to compress the volume and close the forming cavity. Each male element may be connected to an elastic element so that it can perform a settling movement along the longitudinal axis of movement in response to, for example, the compression of the volume at the closed position of the forming cavity. Preferably, a control unit may be programmed to derive check parameters in response to the settling movement. For this purpose, the male elements can perform a settling movement in proportion to, for example, the volume of the volume contained in the forming cavity. The apparatus may include a distance sensor programmed to measure the distance of the settling movement. The control unit can be connected to the distance sensor to receive the distance of the settling movement from the distance sensor. The control unit may be programmed to process check parameters based on the distance received from the distance sensor and derive control parameters. The control unit may be connected to the actuator of at least one partition element among a plurality of partition elements, or to the actuator of at least one partition element, in order to control the upper limit position of that partition element via control parameters. In this way, it becomes possible to adjust the amount of plastic in the working part of the internal volume, and thus to adjust the volume of the dose.

[0050] In one example, the device includes a flow sensor. The flow sensor is preferably configured to measure a flow parameter representing the flow rate of plastic flowing, for example, within a plurality of outlet branches, more preferably within a supply duct. A control unit may be connected to the flow sensor to receive the flow parameter. The control unit may be programmed to drive one or more actuators according to the flow parameter.

[0051] In one example, the device includes a compensation unit, which is preferably located upstream of a plurality of discharge branches of the distribution unit. The compensation unit may be in fluid communication with the supply duct. The compensation unit preferably defines a variable internal compensation volume, for example, from the maximum volume configuration to the minimum volume configuration when the metering unit is in a discharge configuration, and for example, from the minimum volume configuration to the maximum volume configuration when the metering unit is in a filling configuration. The purpose of the compensation unit is to compensate for pressure fluctuations applied by the plastic when the outlet valve system or additional valve system is in a closed configuration.

[0052] In one example, the device includes a compensation actuator connected to a compensation unit to change the compensation volume between, for example, a maximum volume configuration and a minimum volume configuration.

[0053] In one example, the control unit is programmed to derive an imbalance parameter and, preferably, to drive one or more actuators according to the imbalance parameter. The imbalance parameter may represent an imbalance between plastic flow rates in multiple delivery branches, or an imbalance between plastic doses, or an imbalance between molded objects.

[0054] A control unit may be connected to a plurality of outlet valves to control them synchronously. For example, the control unit may synchronously switch the plurality of outlet valves from an open configuration to a closed configuration, and vice versa. Furthermore, the control unit may control the plurality of outlet valves so that each outlet valve is controlled independently of the others. To this end, the control unit may delay the opening and closing of the outlet valves based on, for example, an imbalance parameter, a flow parameter, or a check parameter.

[0055] In one example, the apparatus includes an extruder. The extruder can be connected to a supply duct to supply a continuous flow of pressurized molten plastic to the supply duct. The apparatus may also include a positive displacement pump located downstream of the extruder and connected to the supply duct to supply pressurized molten plastic to the supply duct. The control unit can be programmed to control the extruder or the positive displacement pump according to one or more of the following parameters: check parameters, flow rate parameters, and imbalance parameters. The purpose of the positive displacement pump is to maintain a constant pressure at the inlet of the distribution unit.

[0056] Therefore, the apparatus can be manufactured according to at least three approaches. In the first approach, the additional valve system preferably comprises a valve (main valve) located in the supply duct, allowing the plastic to flow through the supply duct and allowing the main partition element to move to an upper limit position to receive an amount of plastic (total, equal to the sum of the doses). In the first approach, the plastic starts from a distribution zone and is divided among multiple branches, and the amount of plastic forming the doses may be regulated by secondary partition elements and then separated into doses by an outlet valve system. In the second approach, the additional valve system is located in multiple delivery branches and separates the flow of plastic only after the flow has been divided among multiple delivery branches, starting from the distribution zone. Therefore, in this second approach, the additional valve system comprises multiple valves, the number of valves in the additional valve system preferably equal to the number of delivery branches and the number of partition elements located within the delivery branches, each partition element moving to an upper limit position to receive the corresponding dose. In the second approach, as in the first approach, the outlet valve system then separates the plastic into doses. Therefore, these approaches differ, in particular, in the location of the additional valve system.

[0057] Both approaches have the advantage of providing a particularly accurate volumetric metering system that can accommodate, for example, fluctuations in the flow of plastic delivered from the extruder, or more generally, fluctuations in the flow of plastic upstream of the device.

[0058] In the third approach, the flow of plastic enters a supply duct and is divided between multiple delivery branches, where multiple partition elements positioned at the multiple delivery branches move to an upper limit position with the outlet valve system in a closed configuration to receive the plastic, and then, with the outlet valve system in an open configuration, the multiple partition elements move to a lower limit position to supply the dose toward the outlet, and the outlet valve system returns to a closed configuration to block the flow of plastic and form the dose. Compared to the first and second approaches, the third approach provides a semi-volume metering system, as there are no working parts in the internal volume, and the system comprises a control unit that preferably adjusts the multiple partition elements (or, if present, an extruder or volumetric pump) based on check parameters, imbalance parameters or flow rate parameters to ensure that the doses are accurate and identical to one another.

[0059] This disclosure also relates to a method for manufacturing objects from plastic materials in a continuous cycle.

[0060] The method includes the step of providing a distribution unit which may include a plurality of dispensing branches, each having an outlet. The method includes the step of providing a supply duct which has an inlet. The supply duct may communicate with the plurality of dispensing branches via a distribution zone. Preferably, the distribution unit defines an internal volume between the inlet and the plurality of outlets. The method may include the step of receiving raw plastic into, for example, an extrusion unit. The method may include the step of supplying pressurized molten plastic from, for example, an extrusion unit to a supply duct of the distribution unit. The method may include the step of receiving a flow of molten plastic from, for example, an extrusion unit at the inlet of the supply duct. The method may include the step of distributing the flow of plastic from the inlet of the supply duct to a distribution zone of the distribution unit. The method may include the step of distributing, i.e., splitting, the flow of plastic to a plurality of dispensing branches via the distribution zone.

[0061] This method includes the step of providing a metering unit including an outlet valve system. In one example, the outlet valve system includes a plurality of outlet valves. Each outlet valve may be located at a corresponding discharge branch.

[0062] In one embodiment, the method includes the step of providing a plurality of partition elements. Each partition element of the plurality of partition elements may be positioned in a corresponding distribution branch, preferably upstream of a corresponding outlet valve. Preferably, each partition element of the plurality of partition elements is movable between an upper limit position and a lower limit position, for example, to change the internal volume of a distribution unit.

[0063] This method may include the step of providing a group of actuators.

[0064] Each actuator in a group of actuators may be connected to a corresponding partition element to move that partition element between an upper limit position and a lower limit position. In other words, the method may include the step of moving at least one of the partition elements between an upper limit position and a lower limit position by an actuator. The method may include the step of closing an outlet valve system, for example via a control unit, to block the flow of plastic being discharged from the distribution unit. The method may include the step of controlling one or more actuators in a group of actuators, for example via a control unit, to move a corresponding partition element from a lower limit position to an upper limit position. The method may include the step of opening an outlet valve system, for example via a control unit, to allow plastic to be discharged from the internal volume of the distribution unit, and the step of controlling one or more actuators in a group of actuators, for example via a control unit, to move a corresponding partition element from an upper limit position to a lower limit position to generate multiple doses of plastic.

[0065] The method includes the step of providing an additional valve system. For example, the method includes the step of locating an additional valve system upstream of the outlet valve system in the direction of supplying plastic from inlet to outlet. The internal volume may include an operating part contained between the additional valve system and the outlet valve system, which is preferably variable from a contracted configuration having a minimum volume to an expanded configuration having a maximum volume. Multiple partition elements may be movable between upper and lower limit positions to change the operating part of the internal volume of the distribution unit. For example, when the multiple partition elements are in the upper limit position, the operating part of the internal volume is in the expanded configuration, and when the multiple partition elements are in the lower limit position, the operating part of the internal volume is in the expanded configuration.

[0066] The method may include the step of closing an outlet valve system and opening an additional valve system, for example via a control unit, to allow the plastic to accumulate in the working part of the internal volume. The method may include the step of separating, i.e., blocking the flow of molten plastic via an additional valve system to form a predetermined amount of plastic. The method may include the step of closing an additional valve system and opening an outlet valve system, for example via a control unit, to allow the plastic to be discharged from the working part of the internal volume. While the additional valve system is closed and the outlet valve system is open, the method may include the step of discharging a dose of plastic through an outlet. The method may include the step of separating, i.e., blocking, a predetermined amount of plastic into an additional predetermined amount of plastic via an outlet valve system to form a dose.

[0067] The method includes the step of supplying a dose to multiple sheets of multiple female elements, preferably simultaneously, wherein the multiple female elements may be arranged in multiple dispensing branches. The method includes the step of compressing a dose between multiple female elements and corresponding multiple male elements in order to form multiple objects of plastic material. In one example, the object is a parison intended to form a container by blow molding. Therefore, the method may include the step of blow molding the object, i.e., the parison, in order to form the container.

[0068] In one example, the method may include the step of providing an outlet valve system including, for example, a plurality of pushers arranged in a plurality of dispensing branches. Each pusher can reciprocate between a retracted position that opens the corresponding dispensing branch and a plurality of forward positions that close the corresponding dispensing branch. The method may also include the step of moving the pusher in the extraction direction between the plurality of forward positions. The method may also include the step of pushing each dose through the corresponding outlet by the corresponding pusher, while keeping, for example, the corresponding outlet valve closed. In other words, each pusher pushes the corresponding dose through the outlet while keeping the corresponding outlet valve closed as it moves in the extraction direction between the plurality of forward positions.

[0069] In one example, in addition to or instead of an outlet valve system, an additional valve system, and a plurality of partition elements, the method includes the steps of providing a plurality of cutting devices, each cutting device being positioned at an outlet; opening each cutting device to allow plastic to be discharged from the outlet; and closing each cutting device to close the outlet and separate the amount of plastic to form a corresponding dose. The device may also include the steps of providing a plurality of sensors and detecting, in real time through each of the plurality of sensors, a flow parameter correlated with the flow rate of plastic in each discharge branch. The method may also include the steps of receiving the flow parameter and closing and opening the cutting devices in accordance with the flow parameter. In one example, the method includes the steps of opening and closing during the step of further opening first and second knives that swap positions and act in conjunction to cut a dose at the outlet.

[0070] In one example, the method includes a step of controlling the upper limit position of at least one of a plurality of partition elements via a control unit. For example, the control step is performed for one molding operation in a series of molding operations. Preferably, the control is based on a parameter representing a previous molding operation or a plurality of previous molding operations. In other words, the method may include a feedback control step. The parameter may be a check parameter, a flow parameter, or an imbalance parameter. In another example, the control is based on a check parameter representing the molding operation in which the control step is performed. For example, the method may include a feedback control step that adjusts the amount of plastic forming the dose. In one example, the method includes a step of moving a plurality of partition elements by an actuator or a group of actuators according to one or more of the check parameter, flow parameter, and imbalance parameter.

[0071] For example, this method includes a step of processing check parameters. This processing step may be performed, for example, by an operator at the end of a molding cycle in the apparatus, or during or at the end of a previous molding operation.

[0072] For example, the method may include the step of measuring the volume or mass of the dose delivered from the delivery branch using an optical sensor or flow sensor. In one example, the method includes the step of moving each female element of a plurality of female elements along a longitudinal axis between a spaced position that does not interfere with the corresponding male element of a plurality of male elements and a close position that closes the forming cavity with respect to the corresponding male element. The method may also include the step of compressing the dose between each female element and the corresponding male element when the forming cavity is in the closed position.

[0073] The method may include a step of compression followed by a step of each male element connected to an elastic element performing a sinking motion along a longitudinal axis of movement. In one example, the method includes a step of deriving check parameters via a control unit, for example, depending on the step of the sinking motion. For this purpose, the method includes a step of adaptively moving the male elements in proportion to the volume of the dose contained in the forming cavity. The method may include a step of measuring the distance of the sinking motion using a distance sensor. The method may include a step of the control unit receiving the distance of the sinking motion from the distance sensor. The method may include a step of processing the check parameters based on the distance received from the distance sensor in order to derive control parameters. The method may include a step of connecting to at least one partition element of a plurality of partition elements, or to at least one actuator of a plurality of partition elements. The method may also include a step of controlling the upper limit position of at least one partition element of a plurality of partition elements using control parameters.

[0074] In one example, the method includes the step of synchronously controlling multiple outlet valves via a control unit.

[0075] In one embodiment, the method includes the step of supplying a continuous flow of pressurized molten plastic to a supply duct through an extruder or through a positive displacement pump located downstream of the extruder and connected to the supply duct. The method may also include the step of controlling the extruder or positive displacement pump via a control unit according to one or more of check parameters, flow rate parameters and imbalance parameters. [Brief explanation of the drawing]

[0076] These and other features will become more apparent from the following description of preferred embodiments shown in the attached drawings as non-limiting examples. [Figure 1] This shows a portion of a container manufacturing line equipped with apparatus according to one or more aspects of this disclosure. [Figure 2] This document shows an apparatus according to one or more aspects of this disclosure. [Figure 3A] Details of an apparatus according to one or more aspects of this disclosure are shown below. [Figure 3B] Details of an apparatus according to one or more aspects of this disclosure are shown below. [Figure 3C] Details of an apparatus according to one or more aspects of this disclosure are shown below. [Figure 3D] This shows one partition element among a plurality of partition elements according to one or more aspects of this disclosure. [Figure 3E] Details of an apparatus according to one or more aspects of this disclosure are shown below. [Figure 3F] Details of an apparatus according to one or more aspects of this disclosure are shown below. [Figure 3G] Details of an apparatus according to one or more aspects of this disclosure are shown below. [Figure 4A] One or more aspects of this disclosure show male and female elements in separated positions. [Figure 4B] One or more aspects of this disclosure show male and female mold elements located in close proximity to close the molding cavity. [Figure 4C]Details of an apparatus according to one or more aspects of this disclosure are shown below. [Figure 4D] One or more aspects of this disclosure show male and female mold elements located in close proximity to close the molding cavity. [Figure 5A-5G] This disclosure shows a series of operational configurations of the device in detail according to one or more aspects of this disclosure. [Figure 6A-6H] This disclosure shows a series of operational configurations of the device in detail according to one or more aspects of this disclosure. [Modes for carrying out the invention]

[0077] Referring to the attached drawing, number 1 indicates an apparatus for manufacturing objects from plastic material in a continuous cycle.

[0078] Apparatus 1 comprises a distribution unit 2. The distribution unit 2 is configured to distribute a flow of molten plastic. The distribution unit 2 includes a supply duct 201 having an inlet 202 and is preferably configured to receive a continuous flow of plastic from an extrusion unit 101. The extrusion unit 101 includes an inlet configured to receive plastic in its raw form and discharge a flow of molten plastic. Preferably, the outlet of the extrusion unit 101 is located in the supply duct 201, i.e., the inlet 202, to receive a flow of molten plastic, for example, a flow of molten plastic in a pressurized form. In one example, the extrusion unit 101 comprises an extruder 101A and a positive displacement pump 101B, the positive displacement pump 101B being located between the extruder 101A and the supply duct 201 and configured to provide a pressurized flow of plastic.

[0079] The distribution unit 2 includes a plurality of outlet branches 203. Each outlet branch 203 is in fluid communication with a supply duct 201 and receives a flow of plastic from the supply duct 201. For this purpose, there is a distribution zone 204 between the supply duct 201 and the plurality of outlet branches 203 that is configured to receive a flow of molten plastic from the supply duct 201 and distribute the flow of molten plastic to each of the plurality of outlet branches 203. In this way, the flow of plastic is divided among the plurality of outlet branches 203. Each outlet branch 203 includes an outlet 205 configured to supply plastic to the distribution unit 2. The distribution unit 2 defines an internal volume between an inlet 202 and the outlets 205 of the plurality of outlet branches 203.

[0080] Preferably, each delivery branch 203 includes a first branch 203A configured to receive plastic from the distribution zone 204 and a second branch 203B including an outlet 205. The first branch 203A and the second branch 203B are in communication with each other and preferably are positioned perpendicular to each other so that the plastic is supplied by gravity through the second branch 203B to the outlet 205. In one example, the distribution zone 204 comprises a first distribution zone 204A located downstream of the supply duct 201 and a second distribution zone 204B located downstream of the first distribution zone 204A. The first distribution zone 204A divides the flow of plastic from the supply duct 201 into a plurality of plastic flows, and the second distribution zone 204B further divides each of the plurality of plastic flows into a further plurality of flows, which are then received by the delivery branch 203.

[0081] The apparatus 1 includes a measuring unit 3 located within the distribution unit 2 and configured to form a volume to be delivered from the outlet 205 from a continuous flow of plastic supplied to the supply duct 201.

[0082] The metering unit 3 includes an outlet valve system 302 that can be switched between a closed configuration and an open configuration. The outlet valve system 302 comprises a plurality of pushers 302A, each pusher 302A positioned in a corresponding delivery branch 203. More specifically, each pusher 302A is inserted into a second branch 203B and is reciprocally movable between a retracted position that does not interfere with the flow of plastic in the second branch 203B and a plurality of forward positions that close the corresponding second branch 203B. In the plurality of forward positions, the pusher 302A is configured to push out the corresponding dose through the outlet 205 by moving in the extraction direction between the forward positions so as to keep the corresponding valve closed.

[0083] In one example, each pusher 302A includes an outer pusher 302B and an inner pusher 302C, with the outer pusher 302B positioned outside the inner pusher 302C. That is, the outer pusher 302B surrounds the outside of the inner pusher 302C. Preferably, the outer pusher 302B and the inner pusher 302C are movable relative to each other. Pusher 302A may also include an air duct 302D contained between the outer pusher 302B and the inner pusher 302C. The air duct 302D is configured to allow airflow to pass through. For example, the outer pusher 302B and the inner pusher 302C can reciprocate (via axial translation) to connect the air duct 302D to the outlet 205, allowing, for example, airflow to exit through the outlet 205. In the retracted position, the outer pusher 302B and the inner pusher 302C work together to block communication between the air duct 302D and the outlet 205. In at least one of the multiple forward positions, the outer pusher 302B and the inner pusher 302C work together to connect the air duct 302D to the outlet 205, in particular allowing airflow to exit through the outlet 205. For example, in at least one of the multiple forward positions, the inner pusher 302C retracts relative to the outer pusher 302B, connecting the air duct 302D to the outlet 205. For example, in at least one of the multiple forward positions, the inner pusher 302C can move forward or backward, resulting in the inner pusher 302C being pulled out (or retracted) relative to the outer pusher 302B to connect the air duct 302D to the outlet 205.

[0084] The weighing unit 3 comprises a plurality of partition elements 303, 303A, and 303B, each movable between an upper limit position X1 and a lower limit position X2. In the example shown in Figure 3C, the plurality of partition elements include a group of partition elements that include a plurality of secondary partition elements 303B. Each of the plurality of secondary partition elements 303B is movable between the upper limit position X1 and the lower limit position X2 to change the internal volume of the distribution unit 2 and is located upstream of the corresponding pusher 302A and within the corresponding discharge branch 203. The weighing unit 3 includes a filling operation configuration in which the pusher 302A is in a closed configuration to block the flow of plastic discharged from the distribution unit 2. In the filling configuration, the secondary partition elements 303B are located at the upper limit position X1, and because the secondary partition elements 303B are located at the upper limit position X1, the internal volume is in an expanded configuration, i.e., a maximum volume configuration. The weighing unit 3 also includes a discharge configuration in which an additional valve system 301 is in a closed configuration and a secondary partition element 303B is positioned at the lower limit position X2, enabling the discharge of plastic from the internal volume and the discharge of the plastic volume through the outlet 205. In the discharge configuration, since the secondary partition element 303B is positioned at the lower limit position X2, the internal volume becomes a contracted configuration, i.e., a minimum volume configuration.

[0085] In one embodiment shown as an example in Figures 3A and 3B, the metering unit 3 includes an outlet valve system 302, an additional valve system 301 comprising a plurality of partition elements 303, 303A, 303B, and a plurality of valves 301. The outlet valve system 302 is positioned downstream of the additional valve system 301 with respect to the supply direction of plastic from the inlet 202 to the outlet 205 of the distribution unit 2. The additional valve system 301 can be switched between an open configuration and a closed configuration. In the open configuration, the additional valve system 301 allows the plastic to advance from the zone upstream of the additional valve system 301 to the zone downstream of the additional valve system 301. Similarly, in the open configuration, the outlet valve system 302 allows the plastic to advance from the zone upstream of the outlet valve system 302 to the zone downstream of the outlet valve system 302. Thus, when transitioning from an open configuration to a closed configuration, the additional valve system 301 and the outlet valve system 302 are configured to divide the flow of molten plastic within the distribution unit 2.

[0086] The internal volume of the distribution unit 2 includes the working parts located between the additional valve system 301 and the outlet valve system 302.

[0087] The weighing unit 3 includes a filling operation configuration in which the outlet valve system 302 is in a closed configuration and an additional valve system 301 is in an open configuration, allowing plastic to accumulate in the working part. In the filling configuration, the partition elements 303, 303A, and 303B are positioned at the upper limit position X1, so the internal volume is in an expanded configuration, i.e., maximum volume configuration. The weighing unit 3 also includes a discharge operation configuration in which the additional valve system 301 is in a closed configuration, the outlet valve system 302 is in an open configuration, and the partition elements 303, 303A, and 303B are positioned at the lower limit position X2, so that plastic can be discharged from the working part of the internal volume and a quantity of plastic can be supplied through the outlet 205. In the discharge configuration, the partition elements 303, 303A, and 303B are positioned at the lower limit position X2, so the working part of the internal volume is in a contracted configuration, i.e., minimum volume configuration.

[0088] Generally speaking, the volume difference between the operating part in the expanded configuration and the operating part in the contracted configuration is equal to the volume of a single dose multiplied by the number of delivery branches 203 in the multiple delivery branches 203.

[0089] In one embodiment shown as an example in Figure 3A, the partition element comprises a plurality of secondary partition elements 303B, each secondary partition element 303B located in the corresponding outlet branch 203 of the plurality of outlet branches 203, and the additional valve system comprises a plurality of valves 301 located upstream of the plurality of secondary partition elements 303B within the plurality of outlet branches 203. In this case, the operating part of the internal volume is located within the plurality of outlet branches 203.

[0090] In one embodiment shown as an example in Figure 3B, the partition element comprises a plurality of secondary partition elements 303B, each secondary partition element 303B located in the corresponding outlet branch 203 of the plurality of outlet branches 203, and the main partition element 303A is located in the supply duct 201. An additional valve system 301 includes a main valve 301A located in the supply duct 201 of the distribution unit 2. More specifically, the main valve 301A is located upstream of the main partition element 303A. In this case, the working part of the internal volume is located between the supply duct 201 and the plurality of outlet branches 203.

[0091] The volume of each dose is equal to the difference between the working part in the expanded configuration and the working part in the contracted configuration, divided by the number of delivery branches 203.

[0092] In exemplary embodiments, each outlet branch 203 includes a secondary leg 207 configured to be in fluid communication with the corresponding outlet branch 203 and to receive the corresponding partition element 303 (specifically, the corresponding secondary partition element 303B).

[0093] In one example, each secondary leg 207 and the corresponding discharge branch 203 are positioned perpendicular to each other (with respect to the flow direction of the plastic). In this example, the volume of one of multiple doses is equal to the difference between the volume of the corresponding secondary leg 207 when the partition element 303 (or secondary partition element 303B) is at the upper limit position X1 and the volume of the corresponding secondary leg 207 when the partition element 303 (or secondary partition element 303B) is at the lower limit position X2.

[0094] In an example comprising a main partition element 303A located downstream of the main valve 301A, the supply duct 201 includes a main leg 206 configured to communicate fluidly with the supply duct 201 and to receive the main partition element 303A. Preferably, the main leg 206 and the supply duct 201 are arranged perpendicular to each other.

[0095] The apparatus 1 includes a control unit 5 configured to switch the weighing unit 3 from a filling configuration to a discharge configuration when the multiple partition elements 303, 303A, and 303B are located at the lower limit position X2, and to switch from a discharge configuration to a filling configuration when the multiple partition elements 303, 303A, and 303B are located at the upper limit position X1.

[0096] Apparatus 1 comprises a forming station 4 for compression molding. The forming station 4 includes a plurality of female elements 401 that can be positioned at a plurality of dispensing branches 203 of a distribution unit 2 to receive a plurality of doses being dispensed from an outlet 205. The plurality of female elements 401 define a plurality of corresponding sheets 402 configured to receive a plurality of corresponding doses of the corresponding plastic being dispensed. More specifically, in the dispensing configuration, an additional valve system 301 is in a closed configuration and the outlet valve system 302 is in an open configuration to supply doses to the plurality of sheets 402 of the plurality of female elements 401. The forming station 4 includes a plurality of male elements 403 that work in conjunction with the plurality of female elements 401 to define a plurality of corresponding forming cavities and are configured to simultaneously form a plurality of objects from the plastic material by compression. For this purpose, each female element 401 is movable along a longitudinal axis of movement X between a spaced position where it does not interfere with the corresponding male element 403 and a close position where it acts in conjunction with the corresponding male element 403 to compress the volume and close the forming cavity. In one example, the control unit 5 is programmed to move each female element 401 along the longitudinal axis of movement X.

[0097] In an exemplary embodiment, the object of plastic material is a parison intended to be formed by subsequent blow molding to create a container. For this purpose, the apparatus 1 may form part of a line 100 for producing containers (for example, for liquids or other purposes) in a continuous cycle, and the production line 100 may comprise a parison blow molding station 102 for forming containers and an extrusion unit 101.

[0098] In one example, the control unit 5 is configured to open and close an additional valve system 301 and an outlet valve system 302.

[0099] In one example, the weighing unit 3 comprises a plurality of actuators or a group of actuators 304, each actuator 304 of the plurality of actuators or group of actuators being connected to partition elements 303, 303A, 303B, specifically to secondary partition elements 303B located on secondary legs 207, to move them between an upper limit position X1 and a lower limit position X2. Alternatively, the partition elements 303, 303A, 303B, specifically the secondary partition element 303B, are configured to move under the influence of plastic pressure, that is, when multiple valves 301 or the main valve 301A are in the open position and the pusher 302A is in the closed position, the partition elements 303, 303A, 303B (or the secondary partition element 303B) are configured to move to an upper limit position X1, and when multiple valves are in the closed position and the pusher 302A is in the open position, the partition elements 303, 303A, 303B (or the secondary partition element 303B) are configured to move to a lower limit position X2 because the pressure that the plastic exerts on the partition elements 303, 303A, 303B is lower.

[0100] The upper limit position X1 is adjustable to change the maximum amount of plastic that can be accommodated in the working part of the internal volume, more specifically to change the volume of the dose.

[0101] The control unit 5 is programmed to drive actuators and control upper limit position X1 and lower limit position X2 based on check parameters, flow parameters, or imbalance parameters. If an extruder 101A and a positive displacement pump 101B are present, the control unit is programmed to control the extruder 101A and the positive displacement pump 101B according to the check parameters, flow parameters, or imbalance parameters. More specifically, for each dispensing branch, the control unit 5 is programmed to receive a check parameter representing the difference between the volume or mass of a single dose dispensed from that dispensing branch and a reference value for the volume or mass of that dose. In one example, the check parameter is derived by an optical sensor that measures the amount of plastic dispensed from outlet 205, or by a flow sensor that measures the flow rate of plastic in a plurality of dispensing branches 203. The check parameter may represent a molding operation that precedes the molding operation in which its upper limit position X1 or lower limit position X2 should be controlled. In other words, the control unit 5 is programmed to adjust the amount of plastic forming a single dose through feedback. In another example, check parameters are processed in real time for the molding operation, checking the position during the same molding operation. Control unit 5 is programmed to process control parameters based on the check parameters. Control unit 5 is connected to each actuator 304, transmits control parameters, and adjusts the upper limit position X1 or lower limit position X2 of the corresponding partition element based on the control parameters.

[0102] In one example, the weighing unit 3 includes a primary actuator 305 connected to the main partition element 303A to move the main partition element 303A between an upper limit position X1 and a lower limit position X2, and for example, a secondary partition element 303B moves between the upper limit position X1 and a lower limit position X2 due to pressure applied by the plastic. In another example, the main partition element 303A and the secondary partition element 303B move between the upper limit position X1 and a lower limit position X2 due to pressure applied by the plastic.

[0103] In one embodiment, each female element 401 of a plurality of female elements 401 is movable along a longitudinal axis of movement X between a spaced position where it does not interfere with the corresponding male element 403 of the plurality of male elements 403, and a close position where it acts in conjunction with the corresponding male element 403 to compress the volume and close the forming cavity. Each male element 403 is connected to an elastic element 404 so that it can perform a sinking motion along the longitudinal axis of movement X in response to the compression of the volume at the closed position of the forming cavity. Thus, the sinking motion performed by the male elements 403 is proportional to the size 406 of the volume of the volume being compressed. For this purpose, the apparatus 1 is equipped with a sensor for measuring the distance 405 of the sinking motion. A control unit 5 is connected to the sensor to receive the distance 405 of the sinking motion and to process check parameters. The control unit 5 is programmed to process control parameters based on the check parameters.

[0104] The control unit 5 is connected to each actuator 304 and transmits control parameters to adjust the upper limit position X1 of the corresponding partition elements 303, 303A, and 303B.

[0105] Preferably, each male mold element 403 comprises a punch 412, a structure 413, a first contact element 407 connected to the structure 413 by a first elastic element 404, and a second contact element 408 connected to the structure by a second elastic element 410. When the female mold element 402 is in proximity, the first contact element 407 is configured to contact the second contact element 408, and the second contact element 408 is configured to contact the forming contact surface 409 of the punch 412, and the punch 412 is configured to perform a sinking motion along a longitudinal movement axis X. More specifically, the sinking motion includes a distance 405 proportional to the size 406 of the volume of a single dose. The control unit 5 is configured to process control parameters according to the distance 405 of the sinking motion and to adjust the upper limit position X1 by the adjustment distance 411 of the partition elements 303, 303A, and 303B.

[0106] In one embodiment, the apparatus includes a flow sensor configured to capture a flow parameter representing the flow rate of plastic flowing through a supply duct 201. A control unit 5 receives the flow parameter and is connected to the flow sensor to drive actuator 304 and, alternatively or additionally, a main actuator 305, according to the flow parameter, and in particular, based on control parameters processed according to the flow parameter.

[0107] In one embodiment, the apparatus 1 includes a compensation unit 208 located within a supply duct 201. The compensation unit 208 may be located within the supply duct 201 and upstream of a plurality of discharge branches 203 in the direction of supplying plastic from an inlet 202 to an outlet 205. If a main valve 301A is present, the compensation unit 208 is located upstream of the main valve 301A. If a plurality of valves 301 are present, the compensation unit 208 is located upstream of the plurality of valves 301. The compensation unit 208 defines a variable internal compensation volume from a maximum volume configuration to a minimum volume configuration when the metering unit 3 is in a discharge configuration, and from a minimum volume configuration to a maximum volume configuration when the metering unit 3 is in a filling configuration. The compensation unit 208 includes a compensation partition element 306. The compensation partition element 306 is preferably freely movable within the compensation unit 208 under pressure applied by the incoming plastic in order to change the amount of plastic contained in the compensation volume. Therefore, it should be noted that the purpose of the compensation unit 208 is to compensate for pressure fluctuations when the main valve 301A or a plurality of valves 301 are in a closed configuration. In one example, the compensation unit 208 is located within the extrusion unit 101. For this purpose, the extrusion unit 101 has a variable volume downstream of its screw feeder, which is configured to retract, for example, to define the compensation volume. In an example not shown, the compensation unit may include a compensation actuator to change the compensation volume between a maximum volume configuration and a minimum volume configuration.

[0108] A method for manufacturing an object from a plastic material in a continuous cycle includes the step of providing a distribution unit 2 which includes a plurality of discharge branches 203, each having an outlet 205, and a supply duct 201 having an inlet 202 and communicating with the plurality of discharge branches 203 through a distribution zone 204. The method includes the step of receiving a pressurized flow of molten plastic from an extrusion unit 101 at the inlet 202, the extrusion unit preferably comprising an extruder 101A and a positive displacement pump 101B.

[0109] This method includes the step of providing a weighing unit 3.

[0110] In one example, the step of providing the weighing unit 3 includes the following substeps: - A substep in which an outlet valve system including multiple pushers 302A is arranged downstream of multiple partition elements 303, wherein each pusher 302A is arranged at a second branch 203B of the corresponding outlet branch 203, - The method includes the substep of arranging a plurality of secondary partition elements 303B downstream of a plurality of valves with respect to the supply direction of plastic from inlet 202 to outlet 205, on a plurality of corresponding secondary legs 207 perpendicular to the first branch 203A of the corresponding delivery branch 203, wherein the method includes the steps of supplying a flow of molten plastic from a supply duct 201 to a distribution zone 204, and distributing, i.e., dividing, the flow of molten plastic from the distribution zone 204 to a plurality of delivery branches 203, while each secondary partition element 303B is moved, for example, by an actuator 304, to an upper limit position X1, i.e., a position where the internal volume of the distribution unit 2 is in an expanded configuration, i.e., a maximum volume configuration. When the secondary partition element 303B of the delivery branch 203 reaches its upper limit position X1, the control unit 5 opens the corresponding pusher 302A, which moves to a retracted position to open a passage for plastic in the second branch 203B. The plastic contained in the internal volume moves forward within the second branch 203B, while the secondary partition element 303B moves from the upper limit position X1 to the lower limit position X2, where the internal volume is contracted or in a minimum volume configuration. When the secondary partition element 303B reaches the lower limit position X2, the control unit 5 closes the pusher 302A, causing the pusher 302A to move from the retracted position toward a plurality of forward positions in the extraction direction. As it moves between the plurality of forward positions in the extraction direction, the pusher 302A separates the plastic contained in the second branch 203B from the plastic contained in the first branch 203A by closing the passage for the plastic in the second branch 203B. As it moves toward the extraction direction, the pusher 302A also pushes the plastic contained in the second branch 203B. In this way, the pusher 302A forms a volume. The volume exits through the corresponding outlet 205 and is supplied by gravity to the sheet 402 of one of the plurality of female elements 401. Therefore, as the plastic moves from the inlet 202 to the multiple outlets 205, it undergoes a first (parallel) separation performed by the distribution zone 204 and a second (series) separation performed by the multiple pushers 302A.

[0111] In one example, each pusher 302A includes an outer pusher 302B and an inner pusher 302C, where the outer pusher 302B is positioned outside the inner pusher 302C (the outer pusher 302B surrounds the outside of the inner pusher 302C). Preferably, the outer pusher 302B and the inner pusher 302C are movable relative to each other. Pusher 302A may also include an air duct 302D contained between the outer pusher 302B and the inner pusher 302C. The air duct 302D is configured to allow airflow to pass through. For example, the outer pusher 302B and the inner pusher 302C can reciprocate (via axial translation) to communicate the air duct 302D with the outlet 205, for example, allowing airflow to exit through the outlet 205. In the retracted position, the outer pusher 302B and the inner pusher 302C work together to block communication between the air duct 302D and the outlet 205. In at least one of the multiple forward positions, the outer pusher 302B and the inner pusher 302C work together to connect the air duct 302D to the outlet 205, in particular allowing airflow to exit through the outlet 205. For example, in at least one of the multiple forward positions, the inner pusher 302C is retracted or withdrawn relative to the outer pusher 302B to connect the air duct 302D to the outlet 205.

[0112] Therefore, in one of the forward positions of the pusher 302A, the inner pusher 302C moves to a retracted or withdrawn position relative to the outer pusher 302B, opening a passage for airflow from the outlet 205 and the air duct 302D. The airflow exits the air duct 302D to separate the dose 20. Subsequently, the dose 20 exits the corresponding outlet 205 and, by gravity, falls onto the sheet 402 of one of the female mold elements 401 of the multiple female mold elements 401.

[0113] As each sheet 402 receives the corresponding amount of plastic, the multiple female elements 401 move along the longitudinal axis of movement X between spaced positions where they do not interfere with the corresponding male elements 403 and close positions where each of them closes the forming cavity with respect to the male elements 403. The method includes a step of compressing the amount, in which each female element 402 and the corresponding male element 403 move closer to each other, thereby forming an object by compression.

[0114] In one example, the method includes the step of arranging an additional valve system 301 including a plurality of valves 301, wherein each of the plurality of valves 301 is positioned in the first branch 203A of the corresponding distribution branch 203. The method includes the step of opening the plurality of valves 301 via a control unit 5. After the plurality of valves are opened, the molten plastic advances and accumulates in the working portion of the internal volume of the distribution unit 2, i.e., the portion between the plurality of valves 301 and the plurality of pushers 302A. Meanwhile, each secondary partition element 303B is moved by, for example, an actuator 304 to an upper limit position X1, i.e., the position where the working portion is in an expanded configuration, i.e., a maximum volume configuration. When the secondary partition element 303B of the distribution branch 203 reaches its upper limit position X1, the control unit 5 closes the corresponding valve 301 and opens the corresponding pusher 302A, which moves the pusher 302A to a retracted position to open a passage for the plastic in the second branch 203B. The plastic contained in the working part of the internal volume advances within the second branch 203B, while the secondary partition element 303B moves from the upper limit position X1 to the lower limit position X2, where the working part is contracted or in a minimum volume configuration. When the secondary partition element 303B reaches the lower limit position X2, the control unit 5 closes the pusher 302A, which separates and pushes out to form a volume, which is then fed out and falls onto the sheet 402. In this example, while the pusher 302A is closed, i.e., while the pusher 302A is moving in the extraction direction, the control unit 5 opens the valve 301 again, allowing the plastic to accumulate in the working part again. Thus, as the plastic advances from the inlet 202 to the multiple outlets 205, it undergoes a first (parallel) separation performed by the distribution zone 204, a second (series) separation performed by the multiple valves 301, and a third (series) separation performed by the multiple pushers 302A.

[0115] In one example, the method includes the steps of placing an additional valve system 301, including a main valve 301A, within a supply duct 201, and placing a main partition element 303A within the supply duct downstream of the main valve 301A and within a main leg 206. The method includes the step of opening the main valve 301 via a control unit 5. After opening the main valve 301A, the molten plastic is advanced and accumulated in the working portion of the internal volume of the distribution unit 2, i.e., the portion between the main valve 301A and the pusher 302A. Meanwhile, the main partition element 303A and the secondary partition element 303B move to an upper limit position X1, i.e., a position where the working portion is in an expanded configuration, i.e., in a maximum volume configuration, for example, the secondary partition element 303B is moved by an actuator 304 and the main partition element 303A is moved by a main actuator 305. When the secondary partition element 303B and the main partition element 303A of the delivery branch 203 reach their respective upper limit positions X1, the control unit 5 closes the main valve 301A and opens the corresponding pusher 302A, which moves to a retracted position to open a passage for the plastic in the second delivery branch 203B. The plastic contained in the working part of the internal volume moves forward within the second branch 203B, while the partition element moves from the upper limit position X1 to the lower limit position X2, where the working part is in a contracted configuration, or minimum volume configuration. When the partition element reaches the lower limit position X2, the control unit 5 closes the pusher 302A, which separates and pushes out to form a volume, which is then delivered and falls onto the sheet 402. In this example, while pusher 302A is closed, i.e., while pusher 302A is moving in the extraction direction, control unit 5 opens main valve 301A again to allow plastic to accumulate again in the working part. Thus, as plastic moves from inlet 202 to multiple outlets 205, plastic undergoes a first (series) separation performed by main valve 301A, a second (parallel) separation performed by distribution zone 204, and a third (series) separation performed by multiple pushers 302A.

[0116] In one embodiment, the method includes a calibration (or adjustment) step based on a previous molding operation or the same molding operation, for adjusting the volume of the dosage for one molding operation in a series of molding operations.

[0117] Preferably, in one or more embodiments, the pushers 302A are synchronized with each other so that each pusher 302A reaches the closed position of the corresponding valve at the same time as the other pushers 302A. In this way, the volume falls simultaneously onto the multiple sheets 402, and the multiple female elements 401 move toward the multiple male elements 402 so that they can work in conjunction with the multiple male elements 402 to compress the multiple volumes. Alternatively, the pushers 302A are controlled to open and close independently of each other, for example, to adjust the amount of plastic dispensed.

[0118] In one embodiment, following the steps of moving and compressing the dose, the method includes the step of each male element 403 connected to the elastic element 404 performing a sinking motion along a longitudinal movement axis X. The sinking motion is proportional to the size 406 of the volume of the dose to be placed on the sheet of the corresponding female element 402. More specifically, the distance 405 of the sinking motion is proportional to the volume 406 of the dose, or a value derived therefrom. The method includes the step of detecting the distance 405 of the sinking motion via a distance sensor and transmitting the distance 405 to a control unit 5. Preferably, the control unit 5 receives the distance 405 and compares the distance 405 to a predetermined distance representing an optimal distance proportional to the optimal volume of the dose. The control unit 5 processes check parameters representing the comparison result and processes control parameters based on the check parameters. The control unit 5 transmits the control parameters to an actuator 304 connected to a secondary partition element 303B to adjust the upper limit position X1. More specifically, if the value of distance 405 is less than a predetermined distance, and therefore the volume of the dose is less than the optimal dose volume, the control unit 5 processes the control parameters to modify the upper limit position X1, for example by adjustment distance 411, in order to guide a larger amount of plastic to the secondary leg 207 compared to the previous molding operation. If the value of distance 405 is greater than a predetermined distance, and therefore the volume of the dose is greater than the optimal dose volume, the control unit 5 processes the control parameters to modify the upper limit position X1 in order to guide a smaller amount of plastic to the secondary leg 207 compared to the previous molding operation.

[0119] Preferably, the method includes the steps of: a step of contacting a first contact element 407 connected to the structure 413 of the male element 403 via a first elastic element 404; and a step of contacting a second contact element 408 connected to the structure of the male element 403 via a second elastic element 408. Following contact with the second contact element 408, the punch 412 of the male element 403 performs a sinking motion along a longitudinal movement axis X of a distance 405.

[0120] In one embodiment, the control unit 5 processes a check parameter. The check parameter represents the difference between the volume or mass of a dose delivered from a delivery branch and a reference value for the volume or mass of that dose. The method includes the step of measuring the volume or mass of the delivered dose with a sensor. Next, the control unit 5 processes the control parameters of the actuator based on the check parameter.

[0121] In another example, the control unit 5 processes control parameters based on flow rate parameters, i.e., parameters representing the flow rate of plastic in the supply duct. In yet another example, the control unit 5 processes control parameters based on imbalance parameters representing imbalances between the flow rates of plastic in multiple delivery branches 203, and drives actuators of partition elements based on the imbalance parameters. Preferably, the control unit 5 transmits the control parameters to the extruder 101A or positive displacement pump 101B to adjust the flow of plastic being supplied to the supply duct 201.

[0122] The following paragraphs, listed in alphanumeric order for reference, represent non-limiting exemplary embodiments of the present invention. A. Apparatus (1) for manufacturing an object from a plastic material in a continuous cycle, - Distribution unit (2), A distribution unit (2) includes a supply duct (201) having an inlet (202) configured to receive a continuous pressurized flow of molten plastic from an extrusion unit, and a plurality of outlet branches (203) having fluid communication with the supply duct (201) via a distribution zone (204), each of which has an outlet (205), and defines an internal volume between the inlet (202) and the outlet (205). - A forming station (4) for forming multiple objects by compression molding, Multiple female elements (401) that can be placed in multiple output branches (203) of the distribution unit (2) and define multiple corresponding sheets (402), A forming station (4) includes multiple male elements (403) that work in conjunction with multiple female elements (401) to define multiple corresponding forming cavities in order to form multiple objects from a plastic material by compression, A device comprising: a metering unit (3) configured to simultaneously form multiple doses from a continuous flow of plastic in order to supply each of multiple doses to each female element (401) of a plurality of female elements, the metering unit (3) comprising an outlet valve system (302) having a plurality of outlet valves, each outlet valve being located in a corresponding delivery branch (203) and switchable between an open configuration and a closed configuration. A1. The weighing unit (3) includes the following operational configuration, namely, A filling configuration in which the outlet valve system (302) is in a closed configuration to block the flow of plastic sent out from the distribution unit (2), Discharge configuration, including a discharge configuration in which an outlet valve system (302) is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit (2), - The apparatus according to paragraph A, comprising a control unit (5) configured to switch the metering unit (3) from a filling configuration to a discharge configuration and vice versa. A1.1. The metering unit (3) includes a plurality of partition elements (303, 303A, 303B) located upstream of the outlet valve system (302), each of which is movable between an upper limit position (X1) and a lower limit position (X2) to change the internal volume of the distribution unit (2), and the plurality of partition elements includes a group of partition elements located downstream of the supply unit (201). Multiple partition elements (303, 303A, 303B) In the discharge configuration, it moves from the upper limit position (X1) to the lower limit position (X2), The apparatus described in paragraph A1, which moves from the lower limit position (X2) to the upper limit position (X1) in a filling configuration. A1.1.1. The apparatus according to paragraph A1.1, wherein the weighing unit (3) comprises actuators (304, 305) configured to actuate the movement of at least one of a plurality of partition elements (303, 303A, 303B) between an upper limit position (X1) and a lower limit position (X2), the actuators being driven by a control unit. A1.1.2. The weighing unit (3) includes an additional valve system (301) positioned upstream of the outlet valve system (302) with respect to the direction of plastic supply from the inlet (202) to the outlet (205), and which can be switched between an open configuration and a closed configuration. Multiple partition elements (303, 303A, 303B) are positioned between the additional valve system (301) and the outlet valve system (302), and the internal volume includes the working part contained between the additional valve system (301) and the outlet valve system (302). Each of the multiple partition elements (303, 303A, 303B) is movable between an upper limit position (X1) and a lower limit position (X2) to change the working part of the internal volume of the distribution unit (2). The apparatus according to paragraph A1.1 or A1.1.1, wherein when the metering unit (3) is in a filling configuration, the additional valve system (301) is in an open configuration to allow plastic to accumulate in the working part of the internal volume of the dispensing unit, and when the metering unit (3) is in a discharge configuration, the additional valve system (301) is in a closed configuration to allow plastic to be discharged from the working part of the internal volume and the dose to be sent out through the outlet (205) in order to supply doses to multiple sheets (402) of multiple female elements (401). A1.1.3. The apparatus according to any one of paragraphs A1.1 to A1.1.2, wherein at least one of the multiple partition elements (303, 303A, 303B) defines a plurality of secondary partition elements (303B), and each partition element of the plurality of secondary partition elements (303B) is located in the corresponding discharge branch (203) of the plurality of discharge branches. A1.1.4. The apparatus according to any one of paragraphs A1.1 to A1.1.3, wherein the multiple partition elements (303, 303A, 303B) include a main partition element (303A) located within the supply duct (201) of the distribution unit (2). A1.1.5. The apparatus according to any one of paragraphs A1.1 to A1.1.4, wherein at least one upper limit position (X1) of a plurality of partition elements (303, 303A, 303B) is adjustable to change the maximum amount of plastic that can be accommodated in the working part of the internal volume. A1.1.5.1. For each dispensing branch, the control unit is programmed to receive a check parameter and adjust the upper limit position (X1) of at least one of the multiple partition elements (303, 303A, 303B) according to the check parameter, wherein the check parameter represents the difference between the volume or mass of a single dose dispensed from the dispensing branch and a reference value for the volume or mass of said dose, as described in paragraph A1.1.5 of the apparatus. A1.1.5.1.1. Each of the multiple female elements (401) is movable along a longitudinal axis of movement (X) between a spaced position where it does not interfere with the corresponding male element (403) of the multiple male elements (403) and a close position where it acts in conjunction with the corresponding male element (403) to compress the volume and close the forming cavity, and each male element (403) is connected to an elastic member (404) so ​​that it can sink along the longitudinal axis of movement (X) in response to the compression of the volume in the closed position of the forming cavity, and check parameters are derived according to the sinking motion, as described in paragraph A1.1.5.1. A1.1.5.2. The control unit is programmed to receive a flow parameter for each discharge branch and adjust the upper limit position (X1) of at least one of several partition elements (303, 303A, 303B) according to the flow parameter, the device includes a flow sensor configured to measure a flow parameter representing the flow rate of plastic flowing through the discharge branch, and the control unit is connected to the sensor to receive the flow parameter, the device according to paragraph A1.1.5. A1.2. The apparatus according to any one of paragraphs A1.1 to A1.1.5, comprising a sensor system including multiple sensors, each of which is configured to detect a flow parameter in real time that correlates with the flow rate of plastic in each outlet branch (203), and a control unit (5) connected to the sensor system and the outlet valve system (302) that drives the outlet valve (302) according to the flow parameter. A1.2.1. The apparatus as described in paragraph A1.2, wherein the flow parameter represents the length of the plastic section that is pushed out through each outlet (205) and located outside the distribution unit (2). A2. The apparatus according to any one of paragraphs A to A1.1.5, wherein the outlet valve system (302) comprises a plurality of pushers (302A), each pusher (302A) being reciprocally movable between a retracted position that is positioned on a corresponding dispensing branch (203) and does not obstruct the flow of plastic within the corresponding dispensing branch (203), and a plurality of forward positions that close the corresponding dispensing branch (203), and the pushers (302A) are configured to push a corresponding dose through the outlet (205) by moving in the extraction direction between the plurality of forward positions so as to keep the corresponding outlet valve closed. A3. The apparatus according to any one of paragraphs A to A1.1.5, wherein the outlet valve system (302) comprises a plurality of cutting devices, each cutting device being switchable between an open configuration, where it is located at an outlet (205) and is configured to allow plastic to be discharged from the outlet (205), and a closed configuration, where it closes the outlet (205) to separate the amount of plastic that forms a corresponding dose. A3.1. The apparatus according to paragraph A3, wherein each cutting device comprises a first knife and a second knife, each including a first blade and a second blade positioned on either side of the knife with respect to the direction of movement of the knife, the first knife and the second knife are positioned side by side with respect to the direction of movement, and the first knife and the second knife are movable relative to each other to exchange positions between an open position and a further open position via a closed position when moving from an open position to a further open position. A3.1.1. Apparatus according to paragraph A3.1, wherein, in the closed position of the first and second knives, the first and second knives are configured to work in conjunction to cut off a dose at the outlet. B. A method for manufacturing an object from a plastic material in a continuous cycle, - A distribution unit (2) comprising a plurality of distribution branches (203) each having an outlet (205), and a supply unit (201) having an inlet (202) that communicates with the plurality of distribution branches (203) via a distribution zone (204), wherein the distribution unit (2) defines the internal volume between the inlet (202) and the outlet (205), - A step of receiving the flow of molten plastic from the extrusion unit at the inlet (202) of the supply duct (201), - A step of distributing the flow of plastic to multiple discharge branches (203) via a distribution zone (204), - A step of providing a weighing unit (3), - A step of forming multiple doses from a continuous flow of plastic via an outlet valve system (302) having multiple outlet valves, using a metering unit (3), wherein each outlet valve is located in a corresponding delivery branch (203) and is switchable between an open position and a closed position, - The steps of simultaneously supplying each of the multiple doses to each of the multiple female elements (401) arranged in the multiple dispensing branches (203), A method comprising the steps of: compressing the mass between a plurality of female elements (401) and a corresponding plurality of male elements (403) to form a plurality of objects of plastic material. B1. The following steps are performed by the control unit (5), namely, - A step of switching the weighing unit (3) from a filling configuration that enables blocking the flow of plastic discharged from the dispensing unit (2) to a discharge configuration that enables discharging plastic from its internal volume and supplying a dose of plastic through the outlet (205) to supply a dose to multiple sheets (402) of multiple female mold elements (401), - Includes the step of switching the weighing unit (3) from a discharge configuration to a filling configuration, The method according to paragraph B, wherein the outlet valve system is in a closed configuration when the metering unit (3) is in a filling configuration and in an open configuration when the metering unit (3) is in a discharge configuration. B1.1. - A step of providing a plurality of partition elements (303, 303A, 303B) for a weighing unit (3), wherein each of the plurality of partition elements (303, 303A, 303B) is movable between an upper limit position (X1) and a lower limit position (X2) to change the internal volume of the distribution unit (2), and the plurality of partition elements (303, 303A, 303B) includes a group of partition elements positioned downstream of the supply duct (201), - The process includes the step of moving at least one of the multiple partition elements (303, 303A, 303B) between an upper limit position (X1) and a lower limit position (X2), preferably by actuators (304, 305), Multiple partition elements (303, 303A, 303B) In the discharge configuration, it moves from the upper limit position (X1) to the lower limit position (X2), The method described in paragraph B1, which moves from the lower limit position (X2) to the upper limit position (X1) in a filling configuration. B1.1.1. The weighing unit (3) includes an additional valve system (301) positioned upstream of the outlet valve system (302) with respect to the direction of plastic supply from the inlet (202) to the outlet (205), wherein the working portion of the internal volume contained between the additional valve system (301) and the outlet valve system (302) is variable from a contracted configuration having a minimum volume to an expanded configuration having a maximum volume. This method further includes the following steps performed by the control unit (5): With the metering unit (3) in the filling configuration, the steps include closing the outlet valve system (302) and opening the additional valve system (301), The method according to paragraph B1.1, which includes the steps of closing an additional valve system (301) and opening an outlet valve system (302) while the metering unit (3) is in a discharge configuration. B1.1.2. The method according to any one of paragraphs B1.1 to B1.1.1, wherein at least one upper limit position (X1) of a plurality of partition elements (303, 303A, 303B) is adjusted by a control unit to change the maximum amount of plastic that can be accommodated in the working part of the internal volume. B1.1.2.1. The method according to paragraph B1.1.2, wherein the control unit receives a check parameter (preferably for each dispensing branch) and adjusts the upper limit position (X1) of at least one of the multiple partition elements (303, 303A, 303B) according to the check parameter, the check parameter representing the difference between the volume or mass of a single dose dispensed from the dispensing branch and a reference value for the volume or mass of that dose. B1.1.2.1.1. Each of a plurality of female elements (401) is movable along a longitudinal axis of movement (X) between a spaced position in which it does not interfere with the corresponding male element of a plurality of male elements (403) and a close position in which it acts in conjunction with the corresponding male element (403) to compress the volume and close the forming cavity, and each male element (403) is connected to an elastic element (404) which can perform a sinking motion along the longitudinal axis of movement (X) in response to the compression of the volume in the closed position of the forming cavity, and a control unit derives check parameters in accordance with the sinking motion, as described in paragraph B1.1.2.1. B1.1.2.2. The method according to paragraph B1.1.2, wherein the control unit receives a flow rate parameter representing the flow rate of plastic flowing through the device (preferably within the distribution branch) (preferably for each distribution branch), and adjusts the upper limit position (X1) of at least one of a plurality of partition elements (303, 303A, 303B) according to the flow rate parameter. B1.2. The method according to any one of paragraphs B1.1 to B1.1.2.2, comprising the step of preparing a sensor system including multiple sensors, each of which detects a flow parameter in real time that correlates with the flow rate of plastic in each discharge branch (203), and a control unit (5) connected to the sensor system and outlet valve system (302) that drives the outlet valve (302) according to the flow parameter. B1.2.1. The flow parameter is the length of the plastic section that is pushed out through each outlet (205) and located outside the distribution unit (2), according to the method in paragraph B1.2. B2. The method according to any one of paragraphs B to B1.2.1, wherein the outlet valve system (302) includes a plurality of pushers (302A) arranged in a plurality of delivery branches (203), each pusher (302A) reciprocating between a retracted position that opens the corresponding delivery branch (203) and a plurality of forward positions that close the corresponding delivery branch (203), and as a result the pusher (302A) moves in the extraction direction between the forward positions to push out the corresponding dose through the outlet (205) while keeping the corresponding outlet valve closed. B3. The outlet valve system (302) includes a plurality of cutting devices, each cutting device is located at the outlet (205), and the method is as follows: - The step of opening each cutting device to allow the plastic to be fed out of the outlet (205), The method according to any one of paragraphs B to B2, comprising the step of closing each cutting device to close the outlet (205), thereby separating the amount of plastic that forms the corresponding dose. B3.1. The method according to paragraph B3, wherein each cutting device is configured to block the corresponding exit and define a shutter. B3.1.1. Each cutting device is connected to a control unit, which controls the work cycle and determines the closing time (during which the cutting device / shutter is closed) and the opening time (during which the cutting device / shutter is open), as described in paragraph B3.1. B3.1.1.1. The method according to paragraph B3.1.1, wherein the control unit manages the cutting devices / shutters in different manner so that different work cycles can be set for various cutting devices / shutters. B3.2. - The step of providing a sensor system including multiple sensors, - A step of detecting in real time a flow parameter correlated with the flow rate of plastic in each discharge branch (203) via each of a plurality of sensors, wherein the flow parameter represents the length of the section of plastic that is pushed out through each outlet (205) and located outside the distribution unit (2), - The method according to any one of paragraphs B3 to B3.1.1.1, comprising the steps of receiving flow parameters via a control unit (5) connected to a cutting device and a sensor system, closing the cutting device and opening the cutting device according to the flow parameters. B3.3. Each cutting device comprises a first knife and a second knife, each of which includes a first blade and a second blade positioned on either side of the knife with respect to the direction of movement of the knife, the first knife and the second knife being juxtaposed with each other along the direction of movement, the method comprising the steps of opening the first knife and the second knife, and closing the first knife and the second knife during the step of further opening the first knife and the second knife, the first knife and the second knife exchanging positions and acting in conjunction to cut a dose at the exit, the method according to any one of paragraphs B3 to B3.2. [Prior art documents] [Patent Documents]

[0123] [Patent Document 1] JP2017177455A [Patent Document 2] JPH06114867A [Patent Document 3] US5858420 [Patent Document 4] IT102021000032507

Claims

1. An apparatus for manufacturing objects from plastic materials in a continuous cycle, - A distribution unit, A distribution unit comprising a supply duct having an inlet configured to receive a continuous pressurized flow of molten plastic, and a plurality of distribution branches, each having an outlet and communicating fluidly with the supply duct via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A forming station for forming multiple objects by compression molding, Multiple female elements that can be arranged at the multiple output branches of the distribution unit and define a plurality of corresponding sheets, A forming station comprising: a plurality of male elements that work in conjunction with the plurality of female elements to define a plurality of corresponding forming cavities for forming a plurality of objects from a plastic material by compression; - A weighing unit, An outlet valve system having multiple outlet valves, each outlet valve being located at a corresponding outlet branch, and the outlet valve system being switchable between an open configuration and a closed configuration, A plurality of partition elements, each of which is located upstream of the corresponding outlet valve and positioned at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, The weighing unit includes the following operational configuration, namely, A filling configuration wherein the outlet valve system is in a closed configuration to block the flow of plastic discharged from the distribution unit, A metering unit comprising: a discharge configuration, wherein the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit; - A control unit, Switch the metering unit from the filling configuration to the discharge configuration, and from the discharge configuration to the filling configuration. A control unit is configured to drive one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position when the weighing unit is in the discharge configuration, and to move it from the lower limit position to the upper limit position when the weighing unit is in the filling configuration, thereby forming multiple doses of plastic and supplying the doses to the multiple sheets. For each dispensing branch, the control unit is programmed to receive a check parameter and drive one or more actuators according to the check parameter, wherein the check parameter represents the difference between the volume or mass of a single dose dispensed from the dispensing branch and a reference value for the volume or mass of said dose.

2. The apparatus according to claim 1, wherein each of the plurality of female elements is movable along a longitudinal axis of movement between a spaced position in which it does not interfere with the corresponding male element of the plurality of male elements and a close position in which it acts in conjunction with the corresponding male element to compress the volume and close the forming cavity, and each male element is connected to an elastic element so as to be able to make adaptive movements along the longitudinal axis of movement in response to the compression of the volume in the closed position of the forming cavity, and the check parameter is derived in accordance with the adaptive movement.

3. The apparatus according to claim 1 or 2, comprising a flow sensor configured to measure a flow parameter representing the flow rate of the plastic flowing in the supply duct, wherein the control unit is connected to the sensor to receive the flow parameter.

4. The apparatus according to claim 3, wherein the control unit is programmed to drive one or more of the actuators according to the flow rate parameter.

5. The apparatus according to claim 1 or 2, wherein the outlet valve system comprises a plurality of pushers, each pusher being reciprocable between a retracted position located at a corresponding dispensing branch and not interfering with the flow of plastic in the corresponding dispensing branch, and a plurality of forward positions that close the corresponding dispensing branch, and the pushers are configured to push out a corresponding amount through the outlet by moving in the extraction direction between the plurality of forward positions so as to keep the corresponding dispensing branch closed.

6. The apparatus according to claim 1 or 2, further comprising a compensation unit positioned upstream of the plurality of discharge branches of the distribution unit and in fluid communication with the supply duct, wherein the compensation unit defines a variable internal compensation volume from the maximum volume configuration to the minimum volume configuration when the metering unit is in the discharge configuration, and from the minimum volume configuration to the maximum volume configuration when the metering unit is in the filling configuration.

7. The apparatus according to claim 6, further comprising a compensation actuator connected to the compensation unit for changing the compensation volume between the maximum volume configuration and the minimum volume configuration.

8. The apparatus according to claim 1 or 2, wherein the control unit is programmed to derive an imbalance parameter and to drive one or more of the actuators according to the imbalance parameter, the imbalance parameter representing an imbalance between the flow rates of the plastic in the plurality of discharge branches.

9. The apparatus according to claim 1 or 2, wherein the control unit is connected to the plurality of outlet valves and controls them synchronously.

10. The system comprises an extruder connected to the supply duct for supplying the continuous flow of pressurized molten plastic to the supply duct, and the control unit is programmed to control the extruder according to one or more of the following parameters, namely, - The aforementioned check parameters, - A flow rate parameter representing the flow rate of the plastic flowing through the supply duct, The apparatus according to claim 1 or 2, which is programmed to control the extruder according to one or more imbalance parameters representing imbalances between the flow rates of the plastic in the plurality of discharge branches.

11. The system comprises an extruder and a positive displacement pump located downstream of the extruder and connected to the supply duct to supply the continuous flow of pressurized molten plastic to the supply duct, wherein the control unit is programmed to control the positive displacement pump according to one or more of the following parameters, namely, - The aforementioned check parameters, - A flow rate parameter representing the flow rate of the plastic flowing through the supply duct, The apparatus according to claim 1 or 2, which is programmed to control the positive displacement pump according to one or more imbalance parameters representing imbalances between the flow rates of the plastic in the plurality of discharge branches.

12. An apparatus for manufacturing an object from a plastic material in a continuous cycle, - A distribution unit, A distribution unit comprising a supply duct having an inlet configured to receive a continuous pressurized flow of molten plastic, and a plurality of distribution branches, each having an outlet and communicating fluidly with the supply duct via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A forming station for forming multiple objects by compression molding, Multiple female elements that can be arranged at the multiple output branches of the distribution unit and define a plurality of corresponding sheets, A forming station comprising: a plurality of male elements that work in conjunction with the plurality of female elements to define a plurality of corresponding forming cavities for forming a plurality of objects from a plastic material by compression; - A weighing unit, An outlet valve system having multiple outlet valves, each outlet valve being located at a corresponding outlet branch, and the outlet valve system being switchable between an open configuration and a closed configuration, A plurality of partition elements, each of which is located upstream of the corresponding outlet valve and positioned at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, The weighing unit includes the following operational configuration, namely, A filling configuration wherein the outlet valve system is in a closed configuration to block the flow of plastic discharged from the distribution unit, A metering unit comprising: a discharge configuration, wherein the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit; - A control unit, Switch the metering unit from the filling configuration to the discharge configuration, and from the discharge configuration to the filling configuration. A control unit is configured to drive one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position when the weighing unit is in the discharge configuration, and to move it from the lower limit position to the upper limit position when the weighing unit is in the filling configuration, thereby forming multiple doses of plastic and supplying the doses to the multiple sheets. The apparatus comprises a flow sensor configured to measure a flow parameter representing the flow rate of the plastic flowing through the supply duct, and the control unit is connected to the sensor to receive the flow parameter.

13. An apparatus for manufacturing an object from a plastic material in a continuous cycle, - A distribution unit, A distribution unit comprising a supply duct having an inlet configured to receive a continuous pressurized flow of molten plastic, and a plurality of distribution branches, each having an outlet and communicating fluidly with the supply duct via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A forming station for forming multiple objects by compression molding, Multiple female elements that can be arranged at the multiple output branches of the distribution unit and define a plurality of corresponding sheets, A forming station comprising: a plurality of male elements that work in conjunction with the plurality of female elements to define a plurality of corresponding forming cavities for forming a plurality of objects from a plastic material by compression; - A weighing unit, An outlet valve system having multiple outlet valves, each outlet valve being located at a corresponding outlet branch, and the outlet valve system being switchable between an open configuration and a closed configuration, A plurality of partition elements, each of which is located upstream of the corresponding outlet valve and positioned at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, The weighing unit includes the following operational configuration, namely, A filling configuration wherein the outlet valve system is in a closed configuration to block the flow of plastic discharged from the distribution unit, A metering unit comprising: a discharge configuration, wherein the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit; - A control unit, Switch the metering unit from the filling configuration to the discharge configuration, and from the discharge configuration to the filling configuration. A control unit is configured to drive one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position when the weighing unit is in the discharge configuration, and to move it from the lower limit position to the upper limit position when the weighing unit is in the filling configuration, thereby forming multiple doses of plastic and supplying the doses to the multiple sheets. The outlet valve system comprises a plurality of pushers, each pusher being reciprocally movable between a retracted position located at a corresponding dispensing branch and not interfering with the flow of plastic within the corresponding dispensing branch, and a plurality of forward positions that close the corresponding dispensing branch, and the pushers are configured to push out a corresponding volume through the outlet by moving in the extraction direction between the plurality of forward positions so as to keep the corresponding dispensing branch closed.

14. An apparatus for manufacturing an object from a plastic material in a continuous cycle, - A distribution unit, A distribution unit comprising a supply duct having an inlet configured to receive a continuous pressurized flow of molten plastic, and a plurality of distribution branches, each having an outlet and communicating fluidly with the supply duct via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A forming station for forming multiple objects by compression molding, Multiple female elements that can be arranged at the multiple output branches of the distribution unit and define a plurality of corresponding sheets, A forming station comprising: a plurality of male elements that work in conjunction with the plurality of female elements to define a plurality of corresponding forming cavities for forming a plurality of objects from a plastic material by compression; - A weighing unit, An outlet valve system having multiple outlet valves, each outlet valve being located at a corresponding outlet branch, and the outlet valve system being switchable between an open configuration and a closed configuration, A plurality of partition elements, each of which is located upstream of the corresponding outlet valve and positioned at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, The weighing unit includes the following operational configuration, namely, A filling configuration wherein the outlet valve system is in a closed configuration to block the flow of plastic discharged from the distribution unit, A metering unit comprising: a discharge configuration, wherein the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit; - A control unit, Switch the metering unit from the filling configuration to the discharge configuration, and from the discharge configuration to the filling configuration. A control unit is configured to drive one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position when the weighing unit is in the discharge configuration, and to move it from the lower limit position to the upper limit position when the weighing unit is in the filling configuration, thereby forming multiple doses of plastic and supplying the doses to the multiple sheets. The apparatus comprises a compensation unit positioned upstream of the plurality of discharge branches of the distribution unit and in fluid communication with the supply duct, wherein the compensation unit defines a variable internal compensation volume from the maximum volume configuration to the minimum volume configuration when the metering unit is in the discharge configuration, and from the minimum volume configuration to the maximum volume configuration when the metering unit is in the filling configuration.

15. An apparatus for manufacturing an object from a plastic material in a continuous cycle, - A distribution unit, A distribution unit comprising a supply duct having an inlet configured to receive a continuous pressurized flow of molten plastic, and a plurality of distribution branches, each having an outlet and communicating fluidly with the supply duct via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A forming station for forming multiple objects by compression molding, Multiple female elements that can be arranged at the multiple output branches of the distribution unit and define a plurality of corresponding sheets, A forming station comprising: a plurality of male elements that work in conjunction with the plurality of female elements to define a plurality of corresponding forming cavities for forming a plurality of objects from a plastic material by compression; - A weighing unit, An outlet valve system having multiple outlet valves, each outlet valve being located at a corresponding outlet branch, and the outlet valve system being switchable between an open configuration and a closed configuration, A plurality of partition elements, each of which is located upstream of the corresponding outlet valve and positioned at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, The weighing unit includes the following operational configuration, namely, A filling configuration wherein the outlet valve system is in a closed configuration to block the flow of plastic discharged from the distribution unit, A metering unit comprising: a discharge configuration, wherein the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit; - A control unit, Switch the metering unit from the filling configuration to the discharge configuration, and from the discharge configuration to the filling configuration. A control unit is configured to drive one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position when the weighing unit is in the discharge configuration, and to move it from the lower limit position to the upper limit position when the weighing unit is in the filling configuration, thereby forming multiple doses of plastic and supplying the doses to the multiple sheets. The control unit is programmed to derive an imbalance parameter and drive one or more of the actuators according to the imbalance parameter, wherein the imbalance parameter represents an imbalance between the flow rates of the plastic in the plurality of discharge branches.

16. An apparatus for manufacturing an object from a plastic material in a continuous cycle, - A distribution unit, A distribution unit comprising a supply duct having an inlet configured to receive a continuous pressurized flow of molten plastic, and a plurality of distribution branches, each having an outlet and communicating fluidly with the supply duct via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A forming station for forming multiple objects by compression molding, Multiple female elements that can be arranged at the multiple output branches of the distribution unit and define a plurality of corresponding sheets, A forming station comprising: a plurality of male elements that work in conjunction with the plurality of female elements to define a plurality of corresponding forming cavities for forming a plurality of objects from a plastic material by compression; - A weighing unit, An outlet valve system having multiple outlet valves, each outlet valve being located at a corresponding outlet branch, and the outlet valve system being switchable between an open configuration and a closed configuration, A plurality of partition elements, each of which is located upstream of the corresponding outlet valve and positioned at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, The weighing unit includes the following operational configuration, namely, A filling configuration wherein the outlet valve system is in a closed configuration to block the flow of plastic discharged from the distribution unit, A metering unit comprising: a discharge configuration, wherein the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit; - A control unit, Switch the metering unit from the filling configuration to the discharge configuration, and from the discharge configuration to the filling configuration. A control unit is configured to drive one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position when the weighing unit is in the discharge configuration, and to move it from the lower limit position to the upper limit position when the weighing unit is in the filling configuration, thereby forming multiple doses of plastic and supplying the doses to the multiple sheets. The control unit is connected to the plurality of outlet valves and controls them synchronously.

17. An apparatus for manufacturing an object from a plastic material in a continuous cycle, - A distribution unit, A distribution unit comprising a supply duct having an inlet configured to receive a continuous pressurized flow of molten plastic, and a plurality of distribution branches, each having an outlet and communicating fluidly with the supply duct via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A forming station for forming multiple objects by compression molding, Multiple female elements that can be arranged at the multiple output branches of the distribution unit and define a plurality of corresponding sheets, A forming station comprising: a plurality of male elements that work in conjunction with the plurality of female elements to define a plurality of corresponding forming cavities for forming a plurality of objects from a plastic material by compression; - A weighing unit, An outlet valve system having multiple outlet valves, each outlet valve being located at a corresponding outlet branch, and the outlet valve system being switchable between an open configuration and a closed configuration, A plurality of partition elements, each of which is located upstream of the corresponding outlet valve and positioned at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, The weighing unit includes the following operational configuration, namely, A filling configuration wherein the outlet valve system is in a closed configuration to block the flow of plastic discharged from the distribution unit, A metering unit comprising: a discharge configuration, wherein the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit; - A control unit, Switch the metering unit from the filling configuration to the discharge configuration, and from the discharge configuration to the filling configuration. A control unit is configured to drive one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position when the weighing unit is in the discharge configuration, and to move it from the lower limit position to the upper limit position when the weighing unit is in the filling configuration, thereby forming multiple doses of plastic and supplying the doses to the multiple sheets. The apparatus comprises an extruder connected to the supply duct for supplying the continuous flow of pressurized molten plastic to the supply duct, and the control unit is programmed to control the extruder according to one or more of the following parameters, namely, - A check parameter representing the difference between the volume or mass of a single dose dispensed from the aforementioned dispensing branch and the reference value of the volume or mass of said dose. - A flow rate parameter representing the flow rate of the plastic flowing through the supply duct, - An apparatus programmed to control the extruder according to one or more imbalance parameters, which represent imbalances between the flow rates of the plastic in the plurality of discharge branches.

18. An apparatus for manufacturing an object from a plastic material in a continuous cycle, - A distribution unit, A distribution unit comprising a supply duct having an inlet configured to receive a continuous pressurized flow of molten plastic, and a plurality of distribution branches, each having an outlet and communicating fluidly with the supply duct via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A forming station for forming multiple objects by compression molding, Multiple female elements that can be arranged at the multiple output branches of the distribution unit and define a plurality of corresponding sheets, A forming station comprising: a plurality of male elements that work in conjunction with the plurality of female elements to define a plurality of corresponding forming cavities for forming a plurality of objects from a plastic material by compression; - A weighing unit, An outlet valve system having multiple outlet valves, each outlet valve being located at a corresponding outlet branch, and the outlet valve system being switchable between an open configuration and a closed configuration, A plurality of partition elements, each of which is located upstream of the corresponding outlet valve and positioned at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, The weighing unit includes the following operational configuration, namely, A filling configuration wherein the outlet valve system is in a closed configuration to block the flow of plastic discharged from the distribution unit, A metering unit comprising: a discharge configuration, wherein the outlet valve system is in an open configuration to allow plastic to be discharged from the internal volume of the distribution unit; - A control unit, Switch the metering unit from the filling configuration to the discharge configuration, and from the discharge configuration to the filling configuration. A control unit is configured to drive one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position when the weighing unit is in the discharge configuration, and to move it from the lower limit position to the upper limit position when the weighing unit is in the filling configuration, thereby forming multiple doses of plastic and supplying the doses to the multiple sheets. The apparatus comprises an extruder and a positive displacement pump located downstream of the extruder and connected to the supply duct to supply the continuous flow of pressurized molten plastic to the supply duct, wherein the control unit is programmed to control the positive displacement pump according to one or more of the following parameters, namely, - A check parameter representing the difference between the volume or mass of a single dose dispensed from the aforementioned dispensing branch and the reference value of the volume or mass of said dose. - A flow rate parameter representing the flow rate of the plastic flowing through the supply duct, - A device programmed to control the positive displacement pump according to one or more imbalance parameters, which represent imbalances between the flow rates of the plastic in the plurality of discharge branches.

19. A method for manufacturing an object from a plastic material in a continuous cycle, - A step of providing a distribution unit including a plurality of discharge branches, each having an outlet, and a supply duct having an inlet that communicates with the plurality of discharge branches via a distribution zone, wherein the distribution unit defines the internal volume between the inlet and the outlet, - A step of receiving the flow of molten plastic at the inlet of the supply duct, - A step of distributing the flow of plastic to the plurality of discharge branches via the distribution zone, - A step of providing a weighing unit, wherein the weighing unit is An outlet valve system having multiple outlet valves, wherein each outlet valve is located at a corresponding outlet branch, A plurality of partition elements, each of which is positioned upstream of the corresponding outlet valve and at the corresponding distribution branch, and each of which is movable between an upper limit position and a lower limit position in order to change the internal volume of the distribution unit, A group of actuators, each actuator of the group of actuators being connected to a corresponding partition element of the plurality of partition elements, and moving it between the upper limit position and the lower limit position, is provided as a step. - Through the control unit, A step of closing the outlet valve system, which involves blocking the flow of plastic discharged from the distribution unit and controlling one or more actuators of the group of actuators to move the corresponding partition element from the lower limit position to the upper limit position. Steps include opening the outlet valve system to allow plastic to be discharged from the internal volume of the distribution unit, and controlling one or more actuators of the group of actuators to move the corresponding partition element from the upper limit position to the lower limit position to form a plurality of doses of plastic; - The step of supplying the amount to multiple sheets of multiple female elements arranged in the multiple delivery branches, - The step of compressing the amount between the plurality of female elements and the corresponding plurality of male elements to form a plurality of objects of plastic material, The method includes the step of moving the partition element by a group of actuators according to a check parameter representing the difference between the volume or mass of a single dose delivered from the delivery branch and a reference value for the volume or mass of said dose.

20. The step of moving the partition element by the group of actuators is performed according to one or more of the following parameters in addition to the check parameter, namely: - A flow rate parameter representing the flow rate of the plastic flowing through the supply duct, The method according to claim 19, wherein the partition element is moved by a group of actuators according to one or more imbalance parameters representing imbalances between the flow rates of the plastic in the plurality of discharge branches.

21. - A step of moving each of the plurality of female elements along the longitudinal axis of movement between a spaced position that does not interfere with the corresponding male element of the plurality of male elements and a close position that closes the forming cavity with respect to the corresponding male element, - A step of compressing the volume between each female element and the corresponding male element when the forming cavity is in the closed position, - A step of performing adaptive movement along the longitudinal axis of movement via each male element connected to the elastic element, The method according to claim 20, comprising the step of deriving the check parameters in accordance with the adaptive movement through the control unit.

22. The method according to any one of claims 19 to 21, further comprising the step of synchronously controlling the outlet valve through the control unit.

23. - A step of supplying a continuous flow of pressurized molten plastic to the supply duct through an extruder or a positive displacement pump located downstream of the extruder and connected to the supply duct, - According to one or more of the following parameters, namely, - The aforementioned check parameters, - A flow rate parameter representing the flow rate of the plastic flowing through the supply duct, The method according to any one of claims 19 to 21, comprising the step of controlling the extruder or the positive displacement pump through the control unit in accordance with one or more imbalance parameters representing imbalances between the flow rates of the plastic in the plurality of discharge branches.

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