NL2011798C2

NL2011798C2 - Method for producing a component from thermoplastic materials as well as such an apparatus.

Info

Publication number: NL2011798C2
Application number: NL2011798A
Authority: NL
Inventors: Tim Willem Joseph Leonard Dassen
Original assignee: Code Product Solutions B V
Priority date: 2013-11-13
Filing date: 2013-11-13
Publication date: 2015-05-19

Description

Method for producing a component from thermoplastic materials as well as such an apparatus

FIELD OF THE INVENTION

The invention relates to method for producing a component from thermoplastic materials, wherein material is being dispensed from a supply device to a feeding device, which material is being plasticized and being transported by the feeding device into a mold, which mold comprises at least a mold cavity and a manifold provided with at least two runners connected to the mold cavity, wherein at least one runner is being opened or closed by a valve, whilst the opening and closing of the valve of the runner is being controlled by control means based on a predetermined amount of plasticized material to be transported through the at least one runner into the mold cavity.

The invention also relates to such an apparatus for producing a component from thermoplastic materials.

BACKGROUND OF THE INVENTION US5762855A discloses an injection molding apparatus comprising a hopper from which plastic pallets are being fed into a cylindrical channel, where the pellets are transported through the length of the channel by a reciprocating screw. As the pellets transverse the channel, the pellets are heated by heater bands and become plasticized. The plasticized material is injected through a manifold of a mold into a mold cavity. The manifold comprises a number of runners (drops). Each runner can be opened and closed by means of a valve through operation of a control system such that the introduction of the plasticized material into the mold cavity can be controlled independent of the other runners. By sequentially opening and closing specific runners, the flow of plasticized material into a mold cavity can be controlled to achieve the desired melt front advancement within the mold cavity.

This apparatus and method is specifically suitable for producing relatively large components for example for the automotive industry.

The dimensions of the relatively large component, especially the thickness of each part of the component is calculated based amongst others on the mechanical properties of the material of the pellets and the desired mechanical properties of the obtained component. To reduce the weight of the component the thickness of parts of the component can be reduced but this will automatically negatively influence the mechanical properties like strength or stiffness of the component. Another possibility is to use material with a lower specific weight but such material must also have the same mechanical properties, price, manufacturing properties etc.

SUMMARY OF THE INVENTION

In view of the above, a general object of the present invention is to provide a method for producing a component from thermoplastic materials, wherein the properties of the component can easily be optimized.

In order to achieve this object, the invention provides a method of the kind mentioned in the opening paragraph, which is further characterized in that the supply device comprises at least two supply units for supplying different materials, wherein the amount of material from each supply unit to the feeding device during the transport of the plasticized material into the mold cavity is being controlled and varied by the control means, based on predetermined combinations of the different materials for producing different parts of the component.

By varying the amount of material from each supply unit to the feeding device during the transport of the plasticized material, the plasticized material that will be inserted into the mold cavity will also vary, so different parts of the component will be made of different combinations of different materials from the supply units. The amount of material from each supply unit is being controlled and varied by the control means, which control means also control the opening and closing of the valve of the runner. In this manner the desired combination of different materials can be directed into the desired runner and through the runner into the desired part of the mold cavity. When changing from a first combination of materials to second combination of materials a mixture of both combinations may occur. The change from the first combination to the second combination can be gradually, in which case a relatively large part of the component will be formed of a mixture of the first and second combination of materials. The properties of this mixture will be determined by the properties of both combinations of materials. The change from the first combination to the second combination can be also be abrupt. In such case, the first and second combination of materials might slightly mix in the feeding device or, depending on features of the materials there will be no mixture at all, so parts made of the mixture of the first and second combination will be relatively small or will not be formed at all. By producing a component by the method according to the invention the dimensions of each part of the component and the properties thereof can individually be optimized. In this manner, for example the total weight of the component can be reduced, whilst maintaining the desired properties of each part of the component. The method can be used for injection molding a component.

In a further embodiment of the method in accordance with the invention, at least a first combination of the different materials from the at least two supply units is being inserted through a first of the at least two runners whilst the second of the at least two runners is closed, after which a second different combination of the different materials from the at least two supply units is inserted through the second of the two runners.

In this manner, through each runner a different combination of materials is sequentially being guided into the mold cavity.

In a further embodiment of the method in accordance with the invention, the at least first and second combination of different materials have different mechanical properties.

By inserting through each runner a different combination of materials into a part of the mold cavity, each part of the component will obtain the desired mechanical properties for said part.

For example, if a specific part of the component need to be relatively stiff, the desired combination of different materials from the supply units is being realized by the control means, and is being guided through the runner which opens into the part of the mold cavity for forming the specific stiff part of the component. Other parts which do not to be as stiff, can be made of another combination of the different materials having a lower weight or lower cost, for example. The thickness of the parts of the components and the combination of the materials from which the parts are being made can be optimized in relation to for example the total weight of the component, whilst still being able to provide each part with the desired properties of said part.

In a further embodiment of the method in accordance with the invention, the at least one runner is heatable.

With a heatable runner, material in the runner can be heated and maintained plasticized or plasticized again to simplify the transport of material through the runner.

In a further embodiment of the method in accordance with the invention, thermoplastic material comprises polyamide or polypropylene.

Large components for example for automotive industry are preferably be made from these materials. These materials have a good performance over weight ratio at relative low costs. Polypropylene is relatively cheap and can be used continuously for temperatures up to 100-120 degrees Celsius. Polyamide is a bit more expensive than polypropylene but can be used continuously for applications loaded with temperatures up to 160-180 degrees Celsius. Both materials have relatively good flow properties.

In a further embodiment of the method in accordance with the invention, at least one of the thermoplastic materials comprises at least one additive of glass, carbon, aramid, silica, and/or minerals.

Such materials can easily be mixed with thermoplastic material like polyamide or polypropylene to change the mechanical properties like stiffness, strength and impact thereof.

In a further embodiment of the method in accordance with the invention, the additive is in the form of relatively short fibers of 0,1 -1 millimeter.

The fibers are for example made of glass or carbon, can easily be mixed with thermoplastic material and provide the thermoplastic material with the desired mechanical properties. The advantage of short fibers is the relatively low cost price, the ease of transport from the supply device to the feeding device and into the mold cavity due to the relative small dimensions of the fibers, the ease of fiber dispersion, nearly no risk of fiber bundling and/or nearly no wear of mold and manifold.

In a further embodiment of the method in accordance with the invention, the additive is in the form of relatively long fibers of l - 15 millimeter.

Such long fibers of for example glass or carbon provides thermoplastic materials higher performance than with short fibers in applications requiring for example enhanced strength, stiffness, impact and/or creep properties.

In a further embodiment of the method in accordance with the invention, the weight of the materials dispensed from the supply units is being determined, controlled and varied.

Based on the measured weight and the known specific weight of the material in the supply unit, the amount and volume of the material transported, from the supply unit to the mold cavity can easily be determined.

The invention also relates to an apparatus for producing a component from thermoplastic materials, which apparatus comprises a feeding device, a supply device for dispensing material to the feeding device, as well as control means, which feeding device comprises heating means to plasticize the material as well as transport means to transport the plasticized material into a mold, which mold comprises at least a mold cavity and a manifold provided with at least two runners connected to the mold cavity, wherein at least one runner can be opened or closed by a valve, whilst the opening and closing of the valve of the runner is controlled by the control means based on a predetermined amount of plasticized material to be transported through the at least one runner into the mold cavity. The apparatus according to the invention is characterized in that the supply device comprises at least two supply units for supplying different materials, wherein the amount of material from each supply unit to the feeding device during the transport of the plasticized material into the mold cavity is controlled and varied by the control means, based on predetermined combinations of the different materials for producing different parts of the component.

During the production of the component, both the opening and closing of the valve of the runner as well as the amount of material from each supply unit inserted into the mold cavity is being controlled by the control means, so that a single component can be formed in one single apparatus with different parts made of a different combination of materials.

In a further embodiment of the apparatus in accordance with the invention, the valve for opening and closing of the runner is located on a side of the runner avert of the mold cavity, adjacent to the feeding device.

In this manner the distance between the feeding device and the valve of the runner will be relatively short and there will be a relatively small amount of plasticized material in the manifold between the feeding device and the valve. As soon as a combination of different materials is leaving the feeding device, which is intended to flow through a specific runner, the valve of the runner is being opened. Firstly the relatively small amount of the previous combination of materials located in the manifold between the feeding device and the valve will flow through the runner, after which the combination of materials intended to flow through the runner, will flow through the runner. If the valve would be located relatively close to the mold cavity, the amount of material in the manifold between the feeding device and the valve would be larger.

In a further embodiment of the apparatus in accordance with the invention, the supply unit comprises a valve to control the dispensing of the material from said supply unit.

Such a valve to control the dispensing of the material, can easily be controlled by the control means to open the valve for example during a specific predetermined time to allow the dispensing of a desired amount of material from the supply unit.

In a further embodiment of the apparatus in accordance with the invention, the supply unit comprises an auger to control the dispensing of the material form said supply unit.

Rotation of the auger can easily be controlled by the control means, for example rotation of the auger during a specific predetermined time to allow the dispensing of a desired amount of material from the supply unit. Dosing of the different materials can be done with volumetric dosing or gravimetric dosing both typically using an auger to transport the materials.

DESCRIPTION OF PREFERRED EMBODIMENTS

The invention will further be explained with reference to the drawings wherein: figures lA and lB show cross sections of a first embodiment of an apparatus according to the invention, figure 2 shows a cross section of a second embodiment of an apparatus according to the invention, whilst mixing a combination of different materials from two supply units and transporting the combination by a feeding device, figure 3 shows a cross section of the second embodiment of an apparatus according to the invention as shown in figure 2, whilst mixing another combination of different materials from two supply units and transporting the other combination by a feeding device, figure 4 shows a cross section of the second embodiment of an apparatus according to the invention as shown in figure 2, whilst transporting different combinations by the feeding device, and mixing another combination, figure 5 shows a cross section of the second embodiment of an apparatus according to the invention as shown in figure 2, whilst mixing and transporting sequentially different combinations by the feeding device, figure 6 shows a front view of a component made by the method according to the invention, figure 7 shows a schematic view of an embodiment of a mold of the first and second embodiment of the apparatus according to the invention, figure 8 shows a cross section in the direction VUI-VIII of the mold as shown in figure 7, figures 9A and 9B show enlarged views of the cross section as shown in figure 8 with a closed valve and opened valve, respectively, figure 10 shows a top view of of the mold as shown in figure 7, with an alternative valve, figures 11A - 11C show several steps during filling of the mold as shown in figure 5.

In the drawings, like reference numerals refer to like elements. DESCRIPTION OF PREFERRED EMBODIMENTS

Figures lA and lB show cross sections of a first embodiment of an apparatus 1 according to the invention for producing a component from thermoplastic materials. The apparatus 1 comprises a feeding device 2 and a supply device 3 for dispensing material to the feeding device 2. The feeding device 2 comprises a frame 4 provided with a longitudinal cylindrical opening 5 in which a screw 6 is located. The screw 6 is rotatable about a central axis 7 of cylindrical opening 5 as well as movable along the central axis 7 in and opposite to a direction indicated by arrow Pi by means of a motor 8 to transport material in the direction indicated by arrow

Pi. The amount of rotation as well as the amount of translation of the screw 6 is being measured by means of a measuring device 9. Around the cylindrical opening 5 heating elements 5’ are located to heat and plasticize thermoplastic material located in the cylindrical opening 5 between the screw 6 and the frame 4.

On a side opposite of the motor 8 the frame 4 is provided with a fixed platen 10 and a movable platen 11 being movable with respect to the fixed platen 10 along guide bars 12. Detachable connected to the fixed platen 10 and the movable platen 11 are parts 13,14 respectively of a mold 15. Between the parts 13,14 a mold cavity 16 is located. The cylindrical opening 5 is connected via an opening 17 in the frame 4 and a manifold (see figure 5) in the mold 15 to the mold cavity 16. The feeding device 2 is provided on a side near the motor 8 with a hopper 18 for feeding material from the supply device 3 into the cylindrical opening 5. The apparatus 1 as described so far as well as the operation thereof is well known in the art, for example from US5762855A.

The supply device 3 comprises two supply units 19, 20 each provide with an auger 21 driven by a motor 22 to transport material from the supply units 19, 20 towards a weighting device 23, 24 for weighting a desired amount of material. Each weighting device 23, 24 comprises a fixed platen 25 with weighting means 26 and a vessel 27 which rests on the weighting means 26, enabling the weighting means 26 to measure the weight of the vessel 27 and the material located therein. This kind of dosing device is known as gravimetric dosing, which is as such known in the art.

By means of the supply units 19, 20 a predetermined desired amount of material can be delivered batch-wise to the hopper 18. The hopper 18 is provided with mixing means to mix the different materials supplied from the different supply units 19, 20.

From each vessel 27 a tube 28 extends towards the hopper 18 to deliver material from the vessels 27 into the hopper 18.

The apparatus 1 according to the invention is provided with control means 29 to which the measuring means 9 as well as the weighting means 26 are connected. Furthermore, the control means 29 is connected to the motors 22 to control the rotation of the augers 21.

In the first supply unit 19 a first thermoplastic material 30 is located whilst in the second supply unit 20 a second thermoplastic material 31 is located. The material 30, 31 is in the form of relatively small parts like fibers, pellets or beads to enable easy transport by means of the augers 21 and to enable accurate dosing a desired amount of the material 30, 31. Each thermoplastic material 30, 31 can be provided with additives such as glass fibers. For example material 30 can be pure polypropylene in a granular shape, whilst material 31 can be polypropylene in a granular shape mixed with long glass fibers.

As can be seen in figure lB by way of an example one after the other a first combination Cl of the materials 30, 31 and a second combination C2 of the materials 30, 31 is being transported through the feeding device 2 by means of the screw 6 towards the mold cavity 16. The operation of the apparatus 1 will further be explained with reference to the figures 5 -6C. The first combination Cl of the materials 30, 31 can be 50% of material 30 and 50% of material 31, whilst the second combination C2 of the materials 30, 31 comprises 25% of material 30 and 75% of material 31.

Figures 2 - 5 show a second embodiment of an apparatus 40 according to the invention. The apparatus 40 comprises the same feeding device 2 as the apparatus 1. The supply device 41 of the apparatus 40 differs from the supply device 3 of the apparatus 1. The supply device 41 comprises two supply units 42, 43 each provide with an auger 44 driven by a motor 45 to transport material from the supply units 42, 43 directly into an inlet opening 46 of the mixing device 47. The amount of material supplied from the supply units 42, 43 is measured by means of gravimetric weighting devices 48 based on loss-of-weight of the supply unit 42, 43 and the reducing amount of material therein. The driving of the motors 45 and thus the amount of material 30, 31 transported by the augers 44 into the mixing device 47 is being controlled by the control means 49. Information from the gravimetric weighting devices 48 is also fed to and used by the control means 49. The mixing device 47 is provided at its lower end with a valve 50 being controlled by the control means 49. After a predetermined desired amount of a combination of different materials has been sufficiently mixed in the mixing device 47, the valve 50 is being opened to guide the combination of different materials into the hopper 18 of the feeding device 2.

As can be seen in figure 2 for example a third combination C3 of an equal mixture of both materials 30, 31 is being formed in the mixing device 47 and after being mixed, the third combination C3 is being fed to the hopper 18 and transported through the feeding device 2 by means of the screw 6 in the direction indicated by arrow Pi.

As can be seen in figure 3 for example a fourth combination C4 of another mixture of both materials 30, 31 is being formed in the mixing device 47 and after being mixed, the fourth combination C4 is being fed to the hopper 18 and transported through the feeding device 2 by means of the screw 6 in the direction indicated by arrow Pi.

As can be seen in the figures 4 and 5 by way of an example sequentially the third combination C3 of the materials 30, 31 and a fourth combination C4 of the materials 30, 31 are being formed in the mixing device 47. Only after a combination C3, C4 has been mixed, the respective mixed combination C3, C4 is being fed to the hopper 18 and transported through the feeding device 2 by means of the screw 6 in the direction indicated by arrow Pi.

Figure 6 shows a component 53 made by the apparatus 1 or 40 of the invention according to the method of the invention.

The component 53 is a plastic tailgate for the automotive industry comprising a first opening 54 for a rear window of a car and a second and third opening 55, 56 for rear lights of said car. As an example, different mechanical requirements can be made on different parts of the tailgate, for example on a first part 57 above the opening 54, second and third parts 58, 59 between the opening 54 and the opening 55, 56 respectively and a fourth part 60 between the opening 55 and the opening 56.

To produce the tailgate with for example a relatively low weight whilst all parts 57-60 has the required mechanical properties, the different parts 57-60 are being made of different combinations Cl, C2, C3, C4 of the different materials 30, 31 as a whole in one apparatus 1, 40 with one feeding device 2.

Figures 7-9 show the mold 15 for producing the tailgate. The mold 15 comprises a cavity 61 defining the shape of the tailgate. The mold 15 also comprises a manifold 62 provided with a central opening 63 connected to the opening 17 of the feeding device 2. The manifold 62 further comprises runners 64-67 extending mainly perpendicular to the central axis 6 of the feeding device 2. At ends remote of the central opening 63, the runners 64-67 are connected to runners 68-71 respectively extending parallel to the central axis 6, of the feeding device 2 the runners 68-71 extend from the runners 64-67 to the mold cavity 61. Each runner 64-71 comprises a longitudinal passage allowing plasticized material to flow through the runner into the mold cavity 61.

Each combination of runners 64, 68; 65, 69; 66, 70; 67, 71 is provided with valves being connected to the control means 9, 49, enabling the control means 9, 49 to open and close each valve as desired. Figure 8 shows a cross section in the direction VIII-VHI in figure 7, wherein it can be seen that the runner 69 is provided with a needle-shaped valve 72 being movable in and opposite to the direction indicated by arrow P2 by means of a driving unit 73 under the control of the control means 9, 49 to open and close an opening 74 of the runner 69. The opening 74 is located close to the mold cavity 16. As can also be seen in the figures 7, 8, 9A and 9B the runner 65 extending between the opening 63 and the runner 69, comprises a first relatively short runner part 75 connected to the opening 63, a second relatively short runner part 76 extending parallel to the runner 69 and a relatively long runner part 77 extending perpendicular to the central axis 6 of the feeding device 2. The runner part 76 is provided with a needle-shaped valve 78 being movable in and opposite to the direction indicated by arrow P3 by means of a driving unit 79 under the control of the control means 9, 49 to open and close an opening 80 of the runner 65. In figure 9A the opening 80 is closed by the valve 78, whilst in figure 9B the valve 78 is being moved opposite to the direction indicated by arrow P3 to open the opening 80. Valves 69 for opening and closing runners are well known in the art, for example from US5762855A.

In figure 10 an alternative embodiment of the runner 65 is shown wherein the second relatively short runner part 81 extends perpendicular to the central axis 6 of the feeding device 2.

The runners 64-71 might comprise heating means (not shown) to heat the plasticized material flowing through the runner 64-71 to maintain the desired viscosity of the plasticized material.

The operation of the apparatus 1, 40 as well as the method of the invention will now be explained with reference to the figures 11A-11C.

By the control means 9, 49 the supply device 3, 40 is being controlled to deliver a first combination Cl of materials 30, 31 necessary for molding the first part 54. Furthermore, by the control means 9, 49 the desired amount of said first combination Cl is being determined. Based on the desired amount, the required movement of the screw 6 in the direction indicated by arrow Pi is being calculated. The control means 9, 49 also deliver signals to the respective valves 72, 78 to close the runners 65-67, 69-71 whilst opening the runners 64-68. The first combination Cl of materials 30, 31 is transported from the hopper 18 through the runners 64, 68 into the mold cavity 61 of the mold 15 to form part 57, by a rotational movement as well as a reciprocating movement in and opposite to the direction indicated by arrow Pi of the screw 6 in a manner known in the art. See figure 11A. The movements of the screw 6 are being measured by the measuring means 9 and from these movements the amount of material inserted into the mold cavity 61 can be determined. The information is fed to the control means 9, 49. As soon as the required amount of the first combination inserted in the mold cavity 61 is equal to the desired amount, the valves 72, 78 of the runners 64, 68 are being closed under control of the control means 9, 49 and the valves 72, 78 of the runners 65, 66 are opened. In the meantime, the control means 9, 49 have controlled the supply device 3, 40 to deliver a predetermined amount of a second combination C2 of materials 30, 31 necessary for molding the second and third part 58, 59. This second combination C2 of materials 30, 31 flows right after the first combination Cl of materials 30, 31 by means of the screw 6 through the central opening 5. Since the runner 64 is now closed and the runners 65, 66, 69, 70 are now opened, the second combination C2 of materials 30, 31 will flow through the runners 65, 66 and the runners 69, 70 connected thereto into the mold cavity 61 to form parts 58, 59. See figure 11B. It is not per definition necessary to close runner 64 since this runner is loaded with combination Cl and therefore combination C2 will automatically flow through runners 65, 66 because it is the way of the least resistance for this combination C2. In the mold cavity 61 the melt front of the second combination C2 of materials 30, 31 will flow amongst others towards the part 57 formed from the first combination Cl of materials 30, 31 and will be connected thereto. Preferably it is to open runners 69, 70 if the first combination Cl of materials 30, 31 has passed the opening 74 of the runners 69, 70. Than the melt front is pushed forward with the melt front from combination C2 and no weld lines (colliding flow fronts) will occur. As soon as the required amount of the second combination C2 inserted in the mold cavity 61 is equal to the desired amount, the valves 72, 78 of the runners 65, 66, 69, 70 are being closed under control of the control means 9, 49 and the valves 72, 78 of the runners 67, 71 are opened. In the meantime, the control means 9, 49 have controlled the supply device 3, 40 to deliver a predetermined amount of a third combination C3 of materials 30, 31 necessary for molding the fourth part 60. This third combination C3 of materials 30, 31 flows right after the second combination C2 of materials 30, 31 by means of the screw 6 through the central opening 5. Since the runners 64, 65, 66 are now closed and the runner 67 is now open, the third combination C3 of materials 30, 31 will flow through the runner 67 and the runner 71 connected thereto into the mold cavity 61 to form part 60. See figure 11C. It is not per definition necessary to close the runners 64, 65, 66 since these runners are loaded with combination Cl, C2 and therefore combination C3 will automatically flow through runner 67 because it is the way of the least resistance. In the mold cavity 61 the melt front of the third combination C3 of materials 30, 31 will flow amongst others towards the parts 58, 59 formed from the second combination C2 of materials 30, 31 and will be connected thereto. Preferably it is to open runner 71 if the second combination C2 of materials 30, 31 has passed the opening 74 of the runner 71. Than the melt front is pushed forward with the melt front from combination C3 and no weld lines (colliding flow fronts) will occur.

If desired, a final packing phase can be used with a fourth combination of materials 30, 31, where only a relatively small amount of material will enter the mold cavity 61 to compensate for shrinkage of the materials inserted into the mold cavity 61. During the final packing phase, all valves 72, 78 can be opened so that the fourth combination of materials 30, 31 can flow through all runners 64-71.

The first material 30 can be a thermoplastic material in a granulate shape comprising polyamide or polypropylene, whilst the second material can be a thermoplastic material in a granule shape comprising polyamide or polypropylene containing glass, carbon, aramid, silica, mineral or a combination of these additives in the form of fibers, beads. For example polypropylene with 30% long glass fibers or polyamide with 40% short glass fiber. The fibers can be relatively short fibers of 0,1 - 1 millimeter or relatively long fibers of 1 - 15 millimeter, each with a diameter of 10 - 30 micrometer.

For good separation between two combinations of materials the aspect ratio defined as length over diameter of the granular shape of the two combinations can be different. Preferably the ratio between the highest aspect ratio of the granular shape of a combination of materials and the lowest aspect ratio of the granular shape of the next combination of materials can typically be between a factor of greater than or equal to 1, specifically, 1 to 100 or more specifically, 1 to 10.

For example the parts 57-60 can be made of the following combinations of materials. For example, the first combination Cl of part 57 comprises polypropylene with 60% Long Glass Fiber (PP 60 LGF) combined with pure polypropylene in a ratio of 67:33 leading to polypropylene 40% Long Glass Fiber (PP 40 LGF). For example, the second combination C2 of parts 58, 59 comprises polypropylene with 60% Long Glass Fiber (PP 60 LGF) combined with pure polypropylene in a ratio of 33:67 leading polypropylene 20% Long Glass Fiber (PP 20 LGF). For example, the third combination C3 of parts 60 comprises polypropylene with 60% Long Glass Fiber (PP 60 LGF) combined with pure polypropylene in a ratio of 17:83 leading polypropylene 10% Long Glass Fiber (PP 10 LGF).

Each part 57-60 has different mechanical properties, like strength, ductility, stiffness etc. Based on the above given combinations Cl, C2 and C3 the parts 57-61 may obtain the following properties - part 57 of PP 40 LGF: Emodulus at 23°C: 8300 MPa; strength at 23°C: 121 MPA; charpy at -30°C: 48 lcj/m2; - parts 58, 59 of PP 20 LGF: Emodulus at 23°C: 4800 MPA; strength at 23°C: 90 MPA; charpy at -30°C: 24 lcj/m2 - part 60 of PP 10 LGF: Emodulus at 23°C: 3000; strength at 23°C: 70 MPA; charpy at -30°C: 12 lcj/m2, with the tensile modulus according to ISO 527/1B, tensile strenght according to ISO 527/1B and charpy impact unnotched according to ISO 179/ieU.

In the screw 6 at the location where for example the front side of the second combination C2 of materials 30, 31 contacts the rear side of the first combination Cl of materials 30, 31, the two combinations Cl, C2 of materials 30, 31 might slightly mix. This mixed portion can be inserted through the runner 64 or through the runners 65, 66 depending on the mechanical requirements on the first part 57 or the second and third part 58, 59. If the mechanical requirements on the first part 57 are relatively strict and higher than on second and third parts 58, 59, it is preferred that the mixed portion is inserted through the runners 65. 66.

It is also possible to vary the combination of materials continuously during molding so that each part of the component is made of a different combination of materials.

It is also possible that only one material of one supply unit is being inserted into the mold cavity in a specific portion of the mold.

The viscosity of the materials and the shape of the granulates and other properties could be matched in such a way that no mixing of the separate materials in the screw 6 appears.

For good separation between combinations of materials the ratio between the highest viscosity of a combination of materials and the lowest viscosity of the next combination of materials can typically be between a factor of greater than or equal to l, specifically, l to 1000, more specifically, 10 to 100, and yet more specifically, 1 to 10.

It is also possible to add magnetic elements to one or more of the combination of materials and to use devices to detect the beginning and end of the flow of the combination of materials comprising the magnetic elements, which detection can be used to control the opening and closing of the runners.

It is also possible to add extra particles of polymers or any other material which could be detected via optical methods or via electro-magnetic or magnetic detection. Also a pressure sensor at one or several positions could detect the pressure at a position or pressure difference over a certain distance to detect the transition from a first combination to a second combination of materials.

It is possible to provide the supply device with more than two supply units, each with a different material so that a large combination of materials can be made during the production of a component.

It is also possible to add foaming agents as an additive by a supply unit to let the material foam and to control and vary with the control means the density of the formed foam. Also at the front of the screw inert gas can be injected in the plastified melt to let the material foam in the mold cavity.

It is possible to let the material fall under gravity through each supply unit into the hopper, or to use other dosing means like vibratory feeders, weigh belt feeders, or pump feeders.

It is also possible to have only have valves 72 to steer the melt front of the different material combination through runners 68-71 and not have the valves 78.

It is possible to produce all kind of automotive components like lift gates, door modules, front end modules, instrument panels, underbody panels, structural reinforcement beams to reinforce Body in White parts, seat parts, etc.. It is also possible to produce other kind of components like a structural frame for solar panels or ATM-device.

The person skilled in the art will realize that the present invention is by no means limited to the preferred embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practising the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Any reference signs in the scope should not be construed as limiting the scope of the claims.

LIST OF REFERENCE SIGNS 1 apparatus 2 feeding device 3 supply device 4 frame 5 cylindrical opening 5’ heating elements 6 screw 7 central axis 8 motor 9 measuring device 10 fixed platen 11 movable platen 12 guide bar 13 part 14 part 15 mold 16 mold cavity 17 opening 18 hopper 19 supply unit 20 supply unit 21 auger 22 motor 23 weighting device 24 weighting device 25 fixed platen 26 weighting means 27 vessel 28 tube 29 control means 30 first material 31 second material 40 apparatus 41 supply device 42 supply unit 43 supply unit 44 auger 45 motor 46 inlet opening 47 mixing device 48 weighting device 49 control means 50 valve 53 component 54 first opening 55 second opening 56 third opening 57 part 58 part 59 part 60 part 61 cavity 62 manifold 63 central opening 64 runner 65 runner 66 runner 67 runner 68 runner 69 runner 70 runner 71 runner 72 valve 73 driving unit 74 opening 75 runner part 76 runner part 77 runner part 78 valve 79 driving unit 80 opening 8i runner part Cl first combination C2 second combination C3 third combination C4 fourth combination Pi arrow P2 arrow P3 arrow

Claims

A method for producing a component (53) of thermoplastic material (30, 31), wherein material (30, 31) is dispensed from a feeding device (3) to a feeding device (2), wherein material is fed through the feeding device (2) ) is plasticized and transported in a mold (15), which mold (15) is provided with at least one mold cavity (16) and a manifold (62) provided with at least two runners connected to the mold cavity (16) (64-71), wherein at least one runner (64-71) is opened or closed by a valve (72, 78), while opening and closing the valve (72, 78) of the runner (64-71) is controlled by control means (49) based on a predetermined amount of plasticized material (30, 31) to be transported by the at least one runner (64-71) into the mold cavity (16), characterized in that the feed device ( 3) comprises at least two supply units (19, 20) for supplying different materials (30, 31), wherein the amount of materials (30, 31) from each feed unit (19, 20) to the feed device (2) during the transport of the plasticized material (30, 31) in the mold cavity (16) is controlled and varied by the control means ( 49) based on predetermined combinations (C1-C4) of the different materials (30, 31) to produce different parts (57-60) of the component (53).

Method according to claim 1, characterized in that at least a first combination (C1-C4) of the different materials (30, 31) of the at least two feed units (19, 20) is introduced by a first of the ten at least two runners (64-71) while the second of the two runners (64-71) is closed, after which a second different combination (C1-C4) of the different materials (30, 31) of the at least two supply units (19 , 20) is inserted by the second of the two runners (64-71).

Method according to claim 1 or 2, characterized in that the at least first and second combination (C1-C4) of the different materials (30, 31) have different mechanical properties.

Method according to one of the preceding claims, characterized in that the at least one runner (64-71) is heatable.

A method according to any one of the preceding claims, characterized in that the thermoplastic material comprises polyamide or polypropylene.

Method according to one of the preceding claims, characterized in that at least one of the thermoplastic materials (30, 31) comprises at least one addition of glass, carbon, aramid, silicon, and / or minerals.

A method according to any one of the preceding claims, characterized in that the addition is in the form of relatively short fibers of 0.1-1 millimeter.

A method according to any one of the preceding claims 1-6, characterized in that the addition is in the form of relatively long fibers of 1-15 millimeters.

A method according to any one of the preceding claims, characterized in that the weight of the materials (30, 31) delivered from the feed units (19, 20) is determined, controlled and varied.

Device (1) for producing a component (53) of thermoplastic materials (30, 31), which device (1) is provided with a feed device (2), a feed device (3) for dispensing material (30 , 31) to the feed device (2) and control means (49), which feed device (2) is provided with heating means (5 ') for softening the material (30, 31) and with transport means for the softened material (30) (31) to be transported in a mold (15), which mold (15) is provided with at least one mold cavity (16) and a manifold (62) provided with at least two runners (64) connected to the mold cavity (16) -71), wherein at least one runner (64-71) can be opened or closed by means of a valve (72, 78), while opening and closing the valve (72, 78) of the runner (64-71) ) is controlled by control means (49) based on a transported through the at least one runner (64-71) into the mold cavity (16) predetermined amount of plasticized material (30, 31), characterized in that the feed device (3) comprises at least two feed units (19, 20) for supplying different materials (30, 31), the amount of material (30 31) from each feed unit (19, 20) to the feed device (2) during the transport of the plasticized material (30, 31) into the mold cavity (16) is controlled and varied by control means (29) based on predetermined combinations (C1-C4) of the different materials (30, 31) to produce different parts (57-60) of the component (53).

Device (1) according to claim 10, characterized in that at least a first combination (C1-C4) of the different materials (30, 31) of the at least two supply units (19, 20) is introduced by a first of the at least two runners (64-71) while the second of the at least two runners (64-71) is closed, after which a second different combination (C1-C4) of the materials (30, 31) of the at least two feed units (19, 20) are inserted by the second of the two runners (64-71).

Device (i) according to claim 11, characterized in that the at least first and second combination (C1-C4) of the different materials (30, 31) have different mechanical properties.

Device (1) according to one of claims 10-12, characterized in that the valve (72, 78) for opening and closing the runner (64-71) is located on one side of the runner (64-) 71) away from the mold cavity (16), near the feed device (2).

Device (1) according to one of the preceding claims 10-13, characterized in that the at least one runner (64-71) is heatable.

Device (1) according to one of the preceding claims 10-14, characterized in that the supply unit (19, 20) comprises a valve (72, 78) for controlling the delivery of the material (30, 31) from the supply unit (19, 20).

Device (1) according to one of the preceding claims 10-15, characterized in that the supply unit (19, 20) comprises a conveyor screw (21) for controlling the delivery of the material (30, 31) from the supply unit (19, 20).

Device (1) according to one of the preceding claims 10-16, characterized in that the device (1) is provided with a weighing device (23, 24) for determining the weight of the materials (30, 31) that are supplied by the supply units (19, 20).