Apparatus for producing plastic blood collection tubes

Abstract

An apparatus (1 ) for producing plastic blood collection tubes (9), comprising - a plurality of molding cavities (2); - a plurality of cores (3); - a post-mold device (4), comprising a plurality of cooling housings (5), in particular thermoregulated cooling housings (5), adapted to receive the blood collection tubes (9) from the cores (3); wherein each core (3) has a molding surface (31 ) provided with an anti-sticking coating or having a surface roughness (Ra) greater than or equal to 0,1 pm, preferably from 0,1 to 1 μm; wherein each molding cavity (2) comprises a first part (21 ), or cavity insert, configured to mold the external lateral surface of a collection tube (9), and a second part (22), or gate insert, configured to mold the external surface of the bottom (92) of the collection tube (9); wherein the first part (21 ) and the second part (22) are adapted to be separated from each other, so that there is a gap (29) therebetween; wherein there is provided at least one channel (211, 212) communicating with said gap (29), adapted to be connected to blowing means adapted to blow air in said gap (29) to aid the removal of each blood collection tube (9) from the respective molding cavity (2).

Description

[0001] APPARATUS FOR PRODUCING PLASTIC BLOOD COLLECTION TUBES

[0002] Field of the invention

[0003] The present invention relates to the field of blood collection tubes made of plastic.

[0004] In particular, the invention relates to an apparatus and to a method for producing blood collection tubes made of plastic.

[0005] Background art

[0006] An evacuated blood collection tube (or BCT) is a sterile plastic or glass test tube that is used to collect blood specimens. It has a colored rubber stopper that creates a vacuum seal inside the tube, enabling a predetermined volume of liquid to be drawn. BCTs may contain additives to stabilize and preserve the blood sample prior to analytical testing. Plastic BCTs offer a safe method for blood collection and reduce the potential for breakage and specimen spillage.

[0007] Polypropylene (PP) has been used in molding and extruding operations to produce articles, such as plastic medical containers and films for the food packaging industry. Polyethylene terephthalate (PET) has more recently been used in molding and extruding operations to produce such articles.

[0008] However, PP and PET are somewhat permeable to nitrogen, oxygen, and other gases and vapors. As a result, PP and PET containers are inherently subject to transmission of gases.

[0009] As the medical industry begins to place increased emphasis on the use of plastic medical products, these permeability problems are particularly disadvantageous. Various techniques and methods have therefore been developed in attempt to improve the gas and vapor barrier of containers made of polymeric materials, such as PP, PET and other polymers.

[0010] One method is to combine the properties of different polymeric materials to produce an article with improved properties by assembling articles made of different materials, such as a tube made of a polymer placed inside another tube made of another polymer, the two polymers being selected for their respective barrier properties to a respective gas / vapor, for example. However, this method is very complex as it requires an additional assembly step to produce the final article, separate production lines to produce the different items, and tight dimensional tolerances for each item to ensure a good fit between items. In general, automation is costly and scrap rates due to fit problems are high with this method.

[0011] Another method is the co-injection molding that allows the fabrication of one article made of different polymeric materials when such materials are compatible with each other. It is thus avoided the assembly operation and the need of different production lines. However, the thickness is to be considered, because the gas barrier mechanism relies on the diffusion of the gas molecules through the material. Thus, in case of an assembly of a tube made of a first polymer with a first thickness and a tube made of a second polymer with a second thickness, to be replaced by an article made by co-injection molding using strictly the same polymeric materials as the article made by two distinct tubes, then the thickness of the co-injected article is to be the sum of the first and the second thickness, with a core layer made of the second polymer of a thickness equal to said second thickness in order to theoretically obtain the same barrier properties.

[0012] As a consequence, the time required to cool the thicker wall of the co-injected article inside the mold is longer than that of each individual item intended for assembly, for which short cooling times are generally required due to their relatively thin wall thickness, which typically varies between 0.6 and 1 .2 mm, and the low temperature of the mold, which is generally thermo-regulated at about 15°C with a water-cooling system. The productivity is thus low.

[0013] Therefore, the need is felt to increase the productivity of the production of plastic blood collection tubes, in particular but not exclusively for producing blood collection tubes made of at least two polymers.

[0014] Summary of the invention

[0015] It is an object of the present invention to increase the productivity of the production of plastic blood collection tubes, in particular but not exclusively of plastic blood collection tubes made by co-injection of at least two polymers.

[0016] In particular, it is an object of the present invention to increase the productivity of the production of plastic blood collection tubes, avoiding defects of the plastic collection tubes.

[0017] In particular, it is an object of the present invention to increase the productivity of the production of plastic blood collection tubes, avoiding defects of the plastic collection tubes when demolding of the collection tubes is done at high temperature.

[0018] The present invention achieves at least one of such objects, and other objects which will be apparent in light of the present description, by means of an apparatus, according to claim 1 , for producing plastic blood collection tubes, comprising

[0019] - a plurality of molding cavities;

[0020] - a plurality of cores;

[0021] - a post-mold device, comprising a plurality of cooling housings, in particular thermoregulated cooling housings, adapted to receive the blood collection tubes from the cores; wherein each core has a molding surface provided with an anti-sticking coating or having a surface roughness Ra greater than or equal to 0,1 pm, preferably from 0,1 to 1 pm; wherein each molding cavity comprises a first part, or cavity insert, configured to mold the external lateral surface of a collection tube, and a second part, or gate insert, configured to mold the external surface of the bottom of the collection tube; wherein the first part and the second part are adapted to be separated from each other, so that there is a gap therebetween; wherein there is provided at least one channel communicating with said gap, adapted to be connected to blowing means adapted to blow air in said gap to aid the removal of each blood collection tube from the respective molding cavity.

[0022] Advantageosly, such apparatus allow to increase the productivity of the apparatus.

[0023] In particular, advantageously, the post-mold device, the anti-sticking coating or the surface roughness Ra of the molding surface of cores, and the provision of said at least one channel and of said gap synergically allow to increase the productivity of the apparatus.

[0024] In particular, such features synergically allow to increase the productivity of the apparatus in particular because such features allow demolding at high temperature. Indeed, the anti-sticking coating or the surface roughness Ra allow to increase productivity in particular because allow to demold the blood collection tubes from the cores at high temperature minimizing defects or without defects, in particular without buckling of the blood collection tubes. The blood collection tubes can then be cooled down in the housings of the post-mold device, so that the cores and the molding cavities are free to be used to produce a new batch (or shot) of blood collection tubes.

[0025] The provision of said at least one channel and of said gap allow to increase productivity in particular because allow to remove the blood collection tubes from the molding cavities at high temperature minimizing defects or without defects, in particular allowing air to be blown into said gap to aid the removal from the molding cavity.

[0026] It is particularly preferable and advantageous that the apparatus comprises an elastic body, preferably an elastic ring, arranged between each first part and second part; the elastic body being adapted to separate the first part and the second part from each other, so that there is said gap therebetween when the mold is open.

[0027] “Roughness” means in particular the arithmetical mean roughness, in particular according to the ISO 4287 standard, in particular the ISO 4287:1997 standard.

[0028] The invention also relates to a method, according to claim 16, to produce plastic blood collection tubes, wherein the blood collection tubes, in particular the molded blood collection tubes, are transferred from the cores to the cooling housings of the post-mold device.

[0029] Further features and advantages of the invention will become more apparent in the light of the detailed description of exemplary but not exclusive embodiments.

[0030] The dependent claims describe particular embodiments of the invention.

[0031] Brief description of the Figures

[0032] In the description of the invention, reference is made to the accompanying drawings, which are provided by way of non-limiting example, in which:

[0033] Fig. 1 schematically shows a perspective view of an apparatus according to the invention, in an operative configuration;

[0034] Fig. 2 schematically shows a perspective view of the apparatus of Fig. 1 , in another operative configuration;

[0035] Fig. 3 schematically shows a perspective view of the apparatus of Fig. 1 , in another operative configuration;

[0036] Fig. 4 schematically shows a perspective view of an example of plastic blood collection tube which can be produced with an apparatus according to the invention; Fig. 4A shows a section of the plastic blood collection tube of Fig. 4;

[0037] Fig. 5 schematically shows part of the surface of a component of an apparatus according to the invention, and of molten polymer on such surface;

[0038] Fig. 6 schematically shows a side view of a variant of apparatus according to the invention, in an operative configuration;

[0039] Fig. 7 schematically shows a side view of the apparatus of Fig. 6, in another operative configuration;

[0040] Fig. 8 schematically shows a side view of the apparatus of Fig. 6, in another operative configuration;

[0041] Fig. 9 shows a section of an example of components of an apparatus according to the invention, in a first configuration, in particular in a first operative configuration; Fig. 9A shows a detail of Fig. 9;

[0042] Fig. 10 shows a section of the components of Fig. 9, in a second configuration, in particular in a second operative configuration;

[0043] Fig. 10A shows a detail of Fig. 10;

[0044] Fig. 11 shows a side view of an example of a component of the apparatus according to the invention;

[0045] Fig. 1 1 A shows a detail of Fig. 11 .

[0046] The same elements, or functionally similar or equivalent elements, have the same reference numerals.

[0047] Description of exemplary embodiments of the invention

[0048] With reference to the Figures, non-limiting exemplary embodiments of an apparatus 1 and of a method according to the invention are described.

[0049] In all the embodiments, the apparatus 1 for producing plastic blood collection tubes 9, in particular to make evacuated blood collection tubes, comprises

[0050] - a plurality of molding cavities 2;

[0051] - a plurality of cores 3;

[0052] - a post-mold device 4, comprising a plurality of cooling housings 5, in particular thermo-regulated cooling housings 5, adapted to receive the blood collection tubes 9 from the cores 3; wherein each core 3 has a molding surface 31 provided with an anti-sticking coating or having a surface roughness Ra greater than or equal to 0,1 pm (micrometers), preferably from 0,1 to 1 pm or comprised between 0,1 and 1 pm; wherein each molding cavity 2 comprises a first part 21 , or cavity insert, configured to mold the external lateral surface of a collection tube 9, and a second part 22, or gate insert, configured to mold the external surface of the bottom 92 of the collection tube 9; wherein, in particular in use, the first part 21 and the second part 22 are adapted to be separated from each other, so that there is a gap 29 therebetween; wherein there is provided at least one channel 211 , 212 communicating with said gap 29, adapted to be connected to blowing means adapted to blow air in said gap 29 to aid the removal of each blood collection tube 9 from the respective molding cavity 2.

[0053] In particular, all or substantially all the molding surface 31 of the cores 3 is provided with the anti-sticking coating or has a surface roughness Ra greater than or equal to 0,1 pm, preferably from 0,1 to 1 pm (micrometers) or comprised between 0,1 and 1 pm.

[0054] The apparatus 1 comprises, in particular, a mold defined in particular by the plurality of molding cavities 2 and the plurality of cores 3.

[0055] In particular, each molding cavity 2 (or female insert) and core 3 (or male insert) are adapted to cooperate to mold a blood collection tube 9. Each molding cavity 2 is configured to mold the external lateral (or side) surface 91 and the external bottom surface 92 of the blood collection tube 9; and each core 3 is configured to mold the internal surface of the blood collection tube 9. The external lateral surface 91 is, in particular, cylindrical or substantially cylindrical.

[0056] The molding cavities 2 are arranged so that they define an array.

[0057] The cores 3 are arranged so that they define an array.

[0058] The molding cavities 2 and the cores 3 are arranged according to the same pattern. In particular, the pitch between the molding cavities 2 is the same as the pitch between the cores 3.

[0059] The molding cavities 2 are carried by a plate, also called cavity plate 20.

[0060] The cores 3 are carried by a plate, also called core plate 30. Between the cavity plate 20 and the core plate 30, another plate, also called stripper plate 39, is preferably provided. The stripper plate 39 carries a plurality of bodies, also called stripping ring, adapted to contact the molded blood collection tubes 9 to eject them from the cores 3.

[0061] Advantageously, the post-mold device 4, the anti-sticking coating or the surface roughness Ra of the molding surface 31 of cores 3, and the provision of said at least one channel 211 , 212 and of said gap 29 synergically allow to increase the productivity of the apparatus 1 .

[0062] Indeed, the anti-sticking coating or the surface roughness Ra allow to demold the blood collection tubes 9 from the cores 3 at high temperature without defects, in particular without buckling of the blood collection tubes 9. The blood collection tubes 9 can then be cooled-down in the housings 5 of the post-mold device 4, so that the cores 3 and the molding cavities 2 are free to be used to produce a new batch of blood collection tubes 9.

[0063] More in details, the anti-sticking coating or the surface roughness Ra of the molding surface 31 of cores 3 are advantageous with respect to a core provided with a mirror polished surface finish, e.g. having a roughness of about 0,02 pm.

[0064] The Inventors have indeed discovered that a mirror polished surface finish of the cores prevents scratches on the surface of the article, but disadvantageously also prevents demolding the blood collection tubes at elevated temperatures. Indeed, with its hollow shape, the blood collection tube naturally shrinks against the core during cooling and the contact surface between the molded article and the core is hence maximal, increasing the friction between those two bodies during the ejection of the blood collection tube that is typically carried out with a mechanical force applied to the blood collection tube along the core axis. In particular, the mechanical force can be applied by the motion along the core axis of the element known as stripper ring, that preferably shapes the open end of the blood collection tube.

[0065] However, if the friction is too high and the solidification of the plastic blood collection tube under cooling does not provide enough rigidity to withstand the mechanical force during the ejection of the molded blood collection tube from the core, then buckling of the molded blood collection tube occurs. Therefore, to solve the buckling issue under ejection conditions, when mirror polished cores are used, it is required to further solidify the blood collection tube by increasing the cooling time within the mold cavity, at the detriment of the productivity. The anti-sticking coating or the surface roughness Ra greater than or equal to 0,1 pm, preferably from 0,1 to 1 pm or comprised between 0,1 and 1 pm, allow to reduce friction between the molded blood collection tube and the core 3 so that the molded blood collection tube can be ejected from the core 3 at a higher demolding temperature without buckling, thereby avoiding or limiting the negative impact on productivity.

[0066] The anti-sticking coating, in particular, is made of a material which is different from the remainder of the core 3.

[0067] Preferably, said anti-sticking coating is made of chromium nitride (CrN), a Diamond-like carbon (DLC) material, or a material comprising silicon.

[0068] In the case of surface roughness Ra greater than or equal to 0,1 pm, preferably from 0,1 to 1 pm or comprised between 0,1 and 1 pm, in particular, the molding surface 31 of each core 3 is provided with a plurality of valleys 311 (Fig. 5); and the molding surface 31 of each core 3 is provided with a plurality peaks 312, in particular smooth peaks. The valleys 311 are, in particular, micro-valleys.

[0069] The valleys 311 are so small that the molten polymer 90 that is viscous has difficulty filling them, thereby reducing the contact surface between the core 3 and the molded blood collection tube 9.

[0070] The valleys 311 , or micro-valleys, can be created for example by a vapor honing, sandblasting or shot peening process. In order to avoid scratches on the surface of the molded blood collection tube during its ejection along the core 3, a buffing operation is preferably subsequently carried out in order to smoothen the sharp peaks which can form with e.g. a vapor honing, sandblasting or shot peening process.

[0071] Thus, preferably, in the case of surface roughness Ra greater than or equal to 0,1 pm, preferably from 0,1 to 1 pm or comprised between 0,1 and 1 pm, preferably, the molding surface 31 of each core 3 is a surface which has been subjected to a vapor honing, sandblasting or shot peening process. Preferably the molding surface 31 of each core 3 is sandblasted. Preferably, after vapor honing, sandblasting or shot peening, the molding surface 31 is a surface which has been subjected to a buffing process to obtain a molding surface 31 provided with smooth peaks 312.

[0072] It has been experimentally observed by the Inventors that by using a sandblasted core molding surface 31 to mold blood collection tubes, the cooling time in the mold can be reduced of more than 50% until buckling occurs, with respect to a mirror- polished core.

[0073] The Inventors estimate that buckling occurs above about 60°C with a mirror polished core molding surface, whereas this problem advantageously only occurs above about 115°C when the core molding surface 31 is sandblasted.

[0074] Advantageously, the post-mold device 4 allows each molded blood collection tube to be cooled individually and quickly outside the mold, thus avoiding problems which occur outside the mold when the blood collection tubes are demolded at a relatively high temperature if the molded blood collection tubes are left to cool down slowly all together to room temperature, i.e. without the post-mold device.

[0075] Advantageously, the post-mold device 4 allows to avoid or minimize problems such as sink marks, sticking between molded blood collection tubes in contact with each other, distortion associated to bow and ovality.

[0076] The apparatus 1 , in particular, is adapted to transfer the molded blood collection tubes 9 to the cooling housings 5 when they are ejected from the cores 3.

[0077] The post mold-device 4 is also called take-out device or end-of-arm-tool. The post-mold device 4 is provided with the plurality of cooling housings 5 (or cooling tubes) for post-mold cooling of the molded blood collection tubes 9.

[0078] The cooling housings 5 are, in particular, thermoregulated, e.g. they are cooled by means of a cooling medium.

[0079] The post-mold device 4, in particular, comprises a plate also called take-out plate 40 which carries the cooling housings 5.

[0080] The take-out plate 40, in particular, is adapted to move form a position inside the mold (between the core plate 30 and the cavity plate 20) when the mold is open, to a position outside the mold (not between the core plate 30 and the cavity plate 20), and vice-versa. The take-out plate 40, in particular, is of the side-entry type, i.e. is adapted to move orthogonally with respect to the longitudinal axis of the cores 3, along a translation axis T.

[0081] Once the molded blood collection tubes 9 have been transferred to the thermoregulated cooling tubes 5, the take-out plate 40 moves away from the core plate 30 and cavity plate 20 in order to carry out the post-mold cooling operation outside the mold, thus freeing the mold for the next molding operation. The thermo-regulated cooling tubes 5 cool the molded blood collection tubes 9 by conduction from its external surface. The thermo-regulated cooling tubes 5, in particular, are designed to take into account the dimensional shrinkage of the molded blood collection tubes during post-mold cooling and thus ensure that contact between the molded blood collection tubes and the thermo-regulated cooling housings 5 lasts as long as possible.

[0082] The number of cooling housings 5 can be the same as the number of cores 3, and in particular the pitch between the cooling housings 5 of said plurality of cooling housings 5 can be equal to the pitch P between the cores 3 of said plurality of cores 3; or the number of said plurality of cooling housings 5 can be a multiple of the number of said plurality of cores 3. The pitch is, in particular, the pitch along the translation axis of the take-out plate 40, i.e. the axis T along which the take-out plate 40 is adapted to translate.

[0083] In particular, with particular reference to Figs. 1 , 2 and 3, the pitch between the cooling housings 5 of said plurality of cooling housings 5 can be equal to the pitch between the cores 3 of said plurality of cores 3, whereby each cooling housing 5 can be aligned with a respective core 3 to receive the blood collection tubes 9, in particular to receive the molded blood collection tubes 9.

[0084] Alternatively, with particular reference to Figs. 6, 7 and 8, the number of said plurality of cooling housings 5 can be a multiple (integer number greater than one) of the number of said plurality of cores 3; and said plurality of cooling housings 5 comprises or is formed by at least two sets of cooling housings 5, arranged so that the pitch between the cooling housings 5 of each set of cooling housings 5 is the same as the pitch between the cores 3, whereby each cooling housing 5 of each set of cooling housings 5 can be aligned with a respective core 3 to receive a blood collection tube 9, in particular to receive a molded blood collection tube 9. Thereby, advantageously, the increased quantity of cooling housings allows to increase the capacity of the take-out plate 40 and enable more than one shot of molded blood collection tubes 9 to be processed. In this manner, the duration of the post-mold cooling of the molded blood collection tubes 9 is not limited by the cycle time of the molded blood collection tubes 9 and can be extended in order to cool the molded blood collection tubes 9 further, and further limit the risk of the problems discussed above when the molded blood collection tubes 9 are left to cool slowly all together to room temperature. This alternative also advantageously allows to extend the post-cooling time within the cooling housings 5, thus both increasing productivity and minimizing defects of the molded blood collection tubes 9.

[0085] In particular, the apparatus 1 can be designed so that a set of cooling housings 5 can receive a shot of molded blood collection tubes while other shot(s) of blood collection tubes 9 are still cooling in one or more of the other sets of cooling housings 5.

[0086] In the non-limitative example shown in Figs. 6, 7 and 8, there are three sets of cooling housings 5.

[0087] Preferably, the post-mold device 4 comprises suction means and is configured so that air can be aspirated from the bottom of each cooling housings 5 by means of said suction means.

[0088] Suction from the bottom of the cooling housings 5 can be advantageously used to make sure that each molded blood collection tube 9 is suitably inserted in the respective cooling housing 5 during all the post-mold cooling operation, and also to make the transfer of each molded blood collection tube 9 from the core 3 into the respective cooling housing 5 more efficient.

[0089] Preferably, the apparatus comprises cooling pins 6 adapted to blow air in the blood collection tubes 9 received in the cooling housings 5.

[0090] The cooling pins 6 are arranged according to the same pattern of the cooling housings 5, or in other words according to the same pattern of the one or more sets of cooling housings 5.

[0091] The cooling pins 6 are, in particular, carried by a plate, or pin plate 60. The cooling pins 6 are in particular adapted to cool the molded blood collection tubes 9 from the inside. In particular, the cooling pins 6 cooperate with the cooling housings 5, in particular outside the mold.

[0092] Preferably, the cooling pins 6 are adapted to be inserted in the molded blood collection tubes 9.

[0093] With particular reference to Fig. 9, 9A, 10, 10A and 4, as already said, each molding cavity 2 comprises a first part 21 , or cavity insert 21 , configured to mold the external lateral surface 91 of a collection tube 9, and a second part 22, or gate insert 22, configured to mold the external surface of the bottom 92 of the blood collection tube 9; in particular wherein said external lateral surface 91 is substantially cylindrical.

[0094] The first part 21 and the second part 22 are adapted to be separated from each other, preferably by a distance of from 0,1 and 1 mm, in particular when the mold starts to open (or more generally when the mold is open, Fig. 10, 10A).

[0095] In particular, the first part 21 and the second part 22 are adapted to be separated from each other in use, in particular when the mold starts to open (or more generally when the mold is open, Fig. 10, 10A).

[0096] Fig. 9 and 9A show a configuration, in particular an operative configuration, wherein the mold is in a closed configuration, wherein the cavity insert 21 is in abutment with the gate insert 22.

[0097] Fig. 10 and 10A show a configuration, in particular an operative configuration, wherein the mold is in an open configuration, wherein the cavity insert 21 and the gate insert 22 are spaced apart from each other, in particular axially spaced apart (in particular along the longitudinal axis of the core). The gap, or empty space, between the cavity insert 21 and the gate insert 22 is indicated with reference numeral 29.

[0098] Advantageously, there is provided at least one channel 211 , 212 (e.g. two channels) communicating with the gap 29 between the cavity insert 21 and the gate insert 22, adapted to be connected to blowing means adapted to blow air in said gap 29 to aid the removal of each blood collection tube 9 from the respective molding cavity 2. Said at least one channel 211 , 212 is preferably made in the cavity insert 21 . The at least one channel could alternatively be made in the gate insert 22. It is however preferable to make the at least one channel 211 , 212 in the cavity insert 21 because in this way the at least one channel 211 , 212 can be connected more easily to the blowing means.

[0099] The at least one channel 211 , 212 preferably has an inlet opening made on the side surface of the cavity insert 21 .

[0100] The at least one channel 211 , 212 preferably has an outlet opening which is radially more internal than the elastic body 8.

[0101] Preferably, there are provided two channels 211 , 212 made in opposite sides of the cavity insert 21 .

[0102] The apparatus 1 is preferably provided with one or more solenoid valves to control the air flow in the at least one channel 211 , 212.

[0103] The apparatus 1 preferably also comprises such blowing means.

[0104] In particular, the parting line 23 between the cavity insert 21 and the gate insert 22 is located at the junction of the spherical cap shaped bottom and the substantially cylindrical portion of the blood collection tube.

[0105] These features allow to increase the productivity of the apparatus. In particular, these features allow to avoid or minimize an issue which could arise when demolding is done at relatively high temperatures. In particular, the molded blood collection tube actually shrinks less than usual, particularly near the gate, where the melt is the last to enter into the mold and is therefore the hottest, and therefore may not release properly from the bottom of the molding cavity, so that a suction effect can be created when the mold opens, resulting in a possible deformation of the bottom of the molded blood collection tube.

[0106] The above-mentioned features allow to slightly separate the cavity insert 21 and the gate insert 22 from each other, e.g. at a distance of approximately 0.1 mm when the mold starts to open, in order to allow blowing of air and detach the bottom 92 of the molded blood collection tube 9 from the gate insert 22.

[0107] It is particularly preferable that the apparatus 1 comprises an elastic body 8, preferably an elastic ring, arranged between each first part 21 and second part 22. The elastic ring is for example an elastomeric or rubber ring, in particular an O-ring.

[0108] The elastic body 8 is preferably in contact with the first part 21 and with the second part 22. The elastic body 8 is preferably arranged in a seat 218, in particular an annular seat, of the cavity insert 21 . In particular, when the mold is in an open configuration, the elastic body 8 is partially arranged in such seat 218.

[0109] The elastic body 8 is adapted to separate the first part 21 and the second part 22 from each other, so that there is said gap 29 therebetween when the mold is open, in particular when the mold starts to open.

[0110] More in details, the apparatus 1 is configured so that, when the mold is open, said elastic body 8 separates the first part 21 and the second part 22 from each other, so that there is said gap 29 therebetween.

[0111] In particular, when the mold is open, the elastic body 8 pushes the first part 21 away from the second part 22.

[0112] When the mold is open, in particular, said gap 29 is delimited by the first part 21 , the second part 22 and the elastic body 8.

[0113] The apparatus 1 is also configured so that when the mold is closed, said elastic body 8 is compressed between the first part 21 and the second part 22.

[0114] When the mold is open, said elastic body 8 is more extended that the compressed configuration assumed by the elastic body 8 when the mold in closed.

[0115] When the mold is closed, each core 3 exerts a force, in particular a closing force, on a respective first part 21 which compresses said elastic body 8.

[0116] In particular, the apparatus 1 is configured so that each core 3 can push the respective first part 21 towards the second part 22, so that the elastic body 8 is compressed.

[0117] In particular, each core 3 has a portion 33 adapted to contact a portion 213 of a respective first part 21 to push it toward the second part 22, so that the elastic body 8 is compressed between the first part 21 and the second part 22.

[0118] Said portion 33 is, in particular, a non-molding portion of the core 3 and preferably is adjacent to the molding surface 31 .

[0119] Preferably, said portion 33 of the core 3 is frusto-conical and said portion 213 of the cavity insert 21 is also frusto-conical.

[0120] In absence of the closing force exerted by the core 3, the elastic body 8 separates the first part 21 and the second part from each other. Preferably, the molding surface 31 of each core 3 is provided with a circumferential groove 32 (Fig. 11 , Fig. 11 A), preferably having a depth from 0,05 to 0,5 mm, or more generally with an undercut, in particular to create a small resistance to detachment that prevents the molded blood collection tube from being sucked into the molding cavity 2 when the mold opens. Thus, this feature allows overcome another issue which may occur when demolding at relatively high temperatures, i.e. the molded blood collection tube could remain in the molding cavity, preventing injection of the next blood collection tube.

[0121] Preferably, the circumferential groove 32 is proximal to the end of the core 3 adapted to mold the internal surface of the bottom 92 of the blood collection tube 9. For example, the circumferential groove 32 is in the half of the molding surface 31 comprising said end of the core 3, preferably between the substantially cylindrical lateral surface and the spherical cap shaped end of the molding surface 31 of the core 3.

[0122] The apparatus 1 is preferably configured to produce plastic blood collection tubes 9 made of at least two polymers, preferably by means of a co-injection process; preferably wherein at least one of said at least two polymers is PET (polyethylene terephthalate) or PP (polypropylene). For example, a layer of a polymer 99 can be between two layers of another polymer 98.

[0123] The invention also relates to a method to produce plastic blood collection tubes 9 by means of an apparatus 1 , wherein the blood collection tubes 9, in particular the molded blood collection tubes 9, are transferred from the cores 3 to the cooling housings 5 of the post-mold device 4.

[0124] In particular, there is provided a step of blowing air into said at least one channel 211 , 212 and into said gap 29 to aid the removal of each blood collection tube 9 from the respective molding cavity 2.

[0125] In particular, the method comprises the steps of a) closing a mold of the apparatus 1 , said mold being defined, in particular, by the plurality of molding cavities 2 and the plurality of cores 3; b) injecting molten polymer into the mold, to mold blood collection tubes 9; c) opening the mold; d) blowing air into said at least one channel 211 , 212 and into said gap 29 to aid the removal of each blood collection tube 9 from the respective molding cavity 2; e) transferring the blood collection tubes 9, in particular the molded blood collection tubes 9, from the cores 3 to the cooling housings 5 of the post-mold device 4. Preferably, the apparatus 1 comprises the elastic body 8, as described above, and in order to close the mold, each core 3 applies a closing force on a respective first part 21 , causing a movement of the first part 21 towards the second part 22, so that the elastic body 8 is compressed between the first part 21 and the second part 22; and in order to open the mold, each core 3 is separated from the respective first part 21 whereby, in particular in absence of said closing force, the elastic body 8 pushes the first part 21 away from the second part 22, whereby there is said gap 29.

Claims

CLAIMS1. An apparatus (1 ) for producing plastic blood collection tubes (9), comprising- a plurality of molding cavities (2);- a plurality of cores (3);- a post-mold device (4), comprising a plurality of cooling housings (5), in particular thermoregulated cooling housings (5), adapted to receive the blood collection tubes (9) from the cores (3); wherein each core (3) has a molding surface (31 ) provided with an anti-sticking coating or having a surface roughness (Ra) greater than or equal to 0,1 pm, preferably from 0,1 to 1 pm; wherein each molding cavity (2) comprises a first part (21 ), or cavity insert, configured to mold the external lateral surface of a collection tube (9), and a second part (22), or gate insert, configured to mold the external surface of the bottom (92) of the collection tube (9); wherein the first part (21 ) and the second part (22) are adapted to be separated from each other, so that there is a gap (29) therebetween; wherein there is provided at least one channel (211 , 212) communicating with said gap (29), adapted to be connected to blowing means adapted to blow air in said gap (29) to aid the removal of each blood collection tube (9) from the respective molding cavity (2).

2. Apparatus (1 ) according to claim 1 , wherein said first part (21 ) is provided with said at least one channel (211 , 212).

3. Apparatus (1 ) according to claim 1 or 2, comprising a mold defined in particular by the plurality of molding cavities (2) and the plurality of cores (3); wherein the first part (21 ) and the second part (22) are adapted to be separated from each other when the mold starts to open, so that there is said gap (29) therebetween.

4. Apparatus (1 ) according to anyone of the preceding claims, comprising an elastic body (8), preferably an elastic ring, arranged between each first part (21 ) and the respective second part (22); the elastic body (8) being adapted to separate the first part (21 ) and the second part (22) from each other, so that there is said gap (29) therebetween when the mold is open; preferably wherein when the mold is open said gap (29) is delimited by the first part (21 ), the second part (22) and the elasticbody (8); preferably wherein the elastic body (8) is in contact with the first part (21 ) and with the second part (22).

5. Apparatus (1 ) according to claim 4, wherein when the mold is open said elastic body (8) separates the first part (21 ) and the second part (22) from each other, so that there is said gap (29) therebetween; in particular wherein when the mold is open the elastic body (8) pushes the first part (21 ) away from the second part (22); said mold being defined in particular by the plurality of molding cavities (2) and the plurality of cores (3).

6. Apparatus (1 ) according to claim 4 or 5, wherein when the mold is closed said elastic body (8) is compressed between the first part (21 ) and the second part (22); said mold being defined in particular by the plurality of molding cavities (2) and the plurality of cores (3).

7. Apparatus (1 ) according to claim 4 or 5 or 6, wherein when the mold is closed each core (3) exerts a force on a respective first part (21 ) which compresses said elastic body (8).

8. Apparatus (1 ) according to anyone of the preceding claims, wherein the molding surface (31 ) of each core (3) is provided with a circumferential groove (32), preferably having a depth from 0,05 to 0,5 mm.

9. Apparatus (1 ) according to anyone of the preceding claims, wherein the number of said plurality of cooling housings (5) is the same as the number of said plurality of cores (3); in particular wherein the pitch between the cooling housings (5) of said plurality of cooling housings (5) is equal to the pitch between the cores (3) of said plurality of cores (3), whereby each cooling housing (5) can be aligned with a respective core (3) to receive the blood collection tubes (9), in particular to receive the molded blood collection tubes (9); the pitch being in particular along the translation axis of a plate, or take-out plate (40), which carries the cooling housings (5).

10. Apparatus (1 ) according to anyone of claims from 1 to 8, wherein the number of said plurality of cooling housings (5) is a multiple of the number of said plurality of cores (3); wherein said plurality of cooling housings (5) comprises or is formed by at least two sets of cooling housings (5), arranged so that the pitch between the cooling housings (5) of each set of cooling housings (5) is the same as the pitchbetween the cores (3), whereby each cooling housing (5) of each set of cooling housings (5) can be aligned with a respective core (3) to receive a blood collection tube (9), in particular to receive a molded blood collection tube (9); the pitch being in particular along the translation axis of a plate, or take-out plate (40), which carries the cooling housings (5).

11. Apparatus (1 ) according to anyone of the preceding claims, comprising cooling pins (6) adapted to blow air in the blood collection tubes (9) received in the cooling housings (5); and / or wherein the post-mold device (4) comprises suction means and is configured so that air can be aspirated from the bottom of each cooling housing (5) by means of said suction means.

12. Apparatus (1 ) according to anyone of the preceding claims, wherein said antisticking coating is made of chromium nitride (CrN), a Diamond-like carbon (DLC) material, or a material comprising silicon.

13. Apparatus (1 ) according to anyone of the preceding claims, wherein the molding surface (31 ) of each core (3) is provided with a plurality of valleys (311 ), preferably having a depth from 0,5 to 2 pm; and wherein the molding surface (31 ) of each core (3) is provided with a plurality peaks (312), in particular smooth peaks.

14. Apparatus (1 ) according to anyone of the preceding claims, wherein the molding surface (31 ) of each core (3) is a surface which has been subjected to a vapor honing, sandblasting or shot peening process, preferably wherein the molding surface (31 ) of each core (3) is sandblasted; preferably wherein after vapor honing, sandblasting or shot peening, the molding surface (31 ) is a surface which has been subjected to a buffing process to obtain a molding surface (31 ) provided with smooth peaks (312).

15. Apparatus (1 ) according to anyone of the preceding claims, configured to produce plastic blood collection tubes (9) made of at least two polymers (98, 99), preferably by means of a co-injection process; preferably wherein at least one of said at least two polymers is PET or PP.

16. Method to produce plastic blood collection tubes (9) by means of an apparatus (1 ) according to anyone of the preceding claims, wherein the blood collection tubes (9), in particular the molded blood collection tubes (9), are transferred from the cores (3) to the cooling housings (5) of the post-mold device (4).

17. Method according to claim 16, wherein there is provided a step of blowing air into said at least one channel (21 1 , 212) and into said gap (29) to aid the removal of each blood collection tube (9) from the respective molding cavity (2).

18. Method according to claim 16 or 17, comprising the steps of a) closing a mold of the apparatus (1 ), said mold being defined, in particular, by the plurality of molding cavities (2) and the plurality of cores (3); b) injecting molten polymer into the mold, to mold blood collection tubes (9); c) opening the mold; d) blowing air into said at least one channel (211 , 212) and into said gap (29) to aid the removal of each blood collection tube (9) from the respective molding cavity (2); e) transferring the blood collection tubes (9), in particular the molded blood collection tubes (9), from the cores (3) to the cooling housings (5) of the post-mold device (4).

19. Method according to anyone of the claims from 16 to 18, wherein the apparatus (1 ) comprises an elastic body (8), preferably an elastic ring, arranged between each first part (21 ) and second part (22), the elastic body (8) being adapted to separate the first part (21 ) and the second part (22) from each other so that there is said a gap (29) therebetween when the mold is open; wherein in order to close the mold, each core (3) applies a closing force on a respective first part (21 ), causing a movement of the first part (21 ) towards the second part (22), so that the elastic body (8) is compressed between the first part (21 ) and the second part (22); and wherein in order to open the mold, each core (3) is separated from the respective first part (21 ) whereby, in particular in absence of said closing force, the elastic body (8) pushes the first part (21 ) away from the second part (22).

Images