Structure of needle board for needle punching machines, method for its production, and needle punching machine comprising such a needle board
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- TTNB ITALIA SRL
- Filing Date
- 2024-07-18
- Publication Date
- 2026-05-27
AI Technical Summary
Existing needle boards for needle-punching machines are heavy, require frequent maintenance and replacement, and consume a lot of energy due to their design and materials.
A needle board structure comprising a flat shape with a predetermined thickness, featuring a first and second rigid layer made of composite materials, and an intermediate rigid layer with an expanded material that provides compressive strength and modulus, allowing for efficient needle retention and easy handling.
The new needle board design reduces energy consumption, facilitates easier handling and maintenance, and allows for the production of more efficient and productive needle-punching machines with reduced wear and tear.
Smart Images
Figure IB2024056997_23012025_PF_FP_ABST
Abstract
Description
TITLESTRUCTURE OF NEEDLE BOARD FOR NEEDLE-PUNCHING MACHINES, METHOD FOR ITS PRODUCTION, AND NEEDLE-PUNCHING MACHINE COMPRISING SUCH A NEEDLE BOARDDESCRIPTIONScope of the invention
[0001] The present invention relates to the field of textile and nonwoven machinery, particularly needlepunching machines.
[0002] More specifically, the invention relates to needle boards for needle-punching machines.
[0003] In addition, the invention relates a method for producing needle boards for needle-punching machines.
[0004] The invention also relates to needle-punching machines that include such needle boards.State of the Art
[0005] Needle-punching machines, as is well known, are used in the field of textiles and nonwoven for the treatment of various types of flat semi-finished products formed from fibers. They normally comprise a movable frame that causes a plurality of needles to make an alternating vertical movement, so that they pass through respective holes in two perforated plates, between which the product to be needled passes, in order to obtain a needled product.
[0006] As also known, needles have an angled butt, a normally cylindrical body, and a needle barb, which may have a specific profile depending on the type ofneedling . The needles are mounted in arrays on one or more needle boards , so that their respective barbs all face the same side of the needle board, normally with angled butts parallel to each other, or with random directions , this depending on the types of needl ing to be done .
[0007] Each needle board includes as many through holes as there are needles , and is removably locked by the movable frame . Speci fically, the movable frame has an upper plate that holds the needle butts pressed against the needle board, and it may have movable side panels with pneumatically operated j aws that li ft up and clamp the lower face of the needle board against the upper plate . In this way, the needle board becomes integral with the movable frame , which can do the needling work by performing vertical reciprocating motion . Some types of needle boards , on simpler needle-punching machines or those of less recent design, are attached to the movable frame by screws , which engage respective holes made in the needle boards themselves .
[0008] Needles must be subj ect to frequent maintenance as they wear out or break, given the labor-intensive needling operation involved .
[0009] Needle boards also need to be replaced periodically, as they become deformed or lose their tolerances , due to intense use , and in particular the holes that hold the needles become enlarged and no longer can hold the needles .
[0010] Therefore , needle boards are components that need to be frequently disassembled for needle maintenance and also replaced several times in the li feof a needle-punching machine .
[0011] In DE8104031U1 , a needle board includes an aluminum layer with a rubber layer on top that provides dovetail seats to accommodate the angled needle butts and hold them resiliently .
[0012] Alternatively, instead of on the angled butts , the rubber layer can create friction against the body of the needles to hold them in place and allow easy assembly / disassembly thereof , as described in GB2228497 , GB1157772 , or US 6444292 . The needles are then held in place by interference with the rubber layer, while the body of the needles is held radially without clearance by the hole walls of the metal layer .
[0013] A needle board comprising a compressible , elastically deformable , foam-like layer between two rigid metal layers is described in US3606654 . The holes in the deformable layer, when the deformable layer is compressed, change shape and hold the needles , and when the deformable layer is released, the holes return to the cylindrical shape and the needles can be introduced or removed for replacement .
[0014] In US3122815 a needle board is described comprising a metal formwork defined by an upper plate , a lower plate , and a perimeter frame formed by four rigid side profiles . The profiles are C-shaped, with middle walls that create the frame for holding the plates , and with end wings that serve to fasten the plates by riveting . The top and bottom plates have through-holes , into which the needles are inserted, so that the angled butts of the needles abut against the upper plate . To give the needles an angle, the top and bottom plates areof fset from each other before riveting to the C-profiles of the frame . The space inside the formwork is filled with resin that is allowed to expand so that a rigid body is expanded inside the formwork .
[0015] The aforementioned needle boards , requiring frequent maintenance , are heavy for operators to li ft , both in removing the needle boards from the machine and in placing them on work surfaces for replacing or checking the integrity of the needles , as well as for repositioning the needle boards on the needle machine .
[0016] The ir weight also causes the needle-punching machines to consume a lot of energy, in addition to requiring powerful motors for alternating head movement .Summary of the invention
[0017] An obj ect of the present invention is to provide a needle board structure for needle-punching machines that saves energy compared with existing needle boards .
[0018] Another obj ect of the present invention is to provide a needle board structure for needle-punching machines that allows easier handling during maintenance and replacement operations than existing needle boards .
[0019] It is also the obj ect of the present invention to provide a needle board structure for needle-punching machines that allows less powerful needle-punching machines to be produced for the same amount of work done .
[0020] A further obj ect of the present invention is to provide a needle board structure for needle-punching machines that enables the production of more productive needle-punching machines with the same power output as existing needle-punching machines , as well as capable ofsaving energy with the same performance .
[0021] It is then an obj ect of the present invention to provide a needle board structure for needle-punching machines that makes it possible to produce needlepunching machines that wear less , with the same amount of power used .
[0022] It is also an obj ect of the present invention to provide a method for the production of a needle board for needle-punching machines that is less complex than existing methods .
[0023] It is yet another obj ect of the present invention to provide a needle-punching machine that is more economical to make , with the same performance and strength, or, to provide a needle-punching machine that is more ef ficient , with the same power and strength .
[0024] These and other obj ects are achieved by a needle board structure for needle-punching machines , the needle board having a flat shape with a predetermined thickness and comprising a plurality of holes each designated to receive the body of a needle-punching needle , the needle board further comprising :- a first face configured to receive angled needle butts at the stop ;- a second face opposite to the first face , wherein the first face is defined by a first rigid layer and the second face is defined by a second rigid layer, wherein the holes pass through the first and second rigid layers with a nominal diameter equal to the needle body diameter that the holes are configuredto accommodate , wherein between the first and second rigid layers is included a compression-rigid intermediate layer passed through the holes , the compression-rigid intermediate layer comprising an expanded material with a density between 30 kg / m3and 900 kg / m3, preferably between 35 and 600 kg / m3, and even more preferably between 40 and 300 kg / m3, wherein the expanded material has a compressive modulus in the elastic range greater than 30 Mpa and a compressive strength greater than 400 kPa, and wherein the rigid intermediate layer has a first face adhering to the first rigid layer, a second face adhering to the second rigid layer, and free side walls facing outward from the needle board, whereby said needle board has a first face defined by the first rigid layer, a second face , defined by the second rigid layer, and free s ide walls defined by said side walls of said intermediate rigid layer .
[0025] In this way, the needle board holds without deforming the pressure caused by the movable frame to hold it steady during needling operations . In fact , the outer frame pres ses the needle board by pressing the angled needle butts against the rigid outer layers but does not deform the intermediate layer, which behaves as a rigid body . In particular, with a compressive modulus in the elastic range greater than 30Mpa and a compressive strength greater than 400 kPa, the pressure appl ied to the head, normally not more than a few bars , does not result in substantial deformation of the rigid intermediate layer, while the low density of thecompression-resistant expanded material allows to achieve the above obj ects of better machine performance , lower energy consumption, and less wear and tear .
[0026] Compared with US3122815 , which provides a side frame to hold an internal foam matrix, the substantial weight of such a frame and its connecting rivets is avoided, substantially reducing the overall weight of the needle board .
[0027] Furthermore , again with respect to US3122815 , according to the invention, although the pressure applied to the head does not result in substantial deformation of the rigid intermediate layer, such pressure and the absence of the lateral retaining frame nevertheless results in minimal elastic deformations of the rigid intermediate layer under compression passed through the holes , reducing the diameter of those holes and thus increasing needle retention during needlepunching of the needle board . When, on the other hand, the needle board is not compressed, the elastically rigid intermediate layer returns the needle to be extracted by overcoming slight friction . In contrast , in US3122815 , the presence of the lateral retaining frame absorbs all the pressure load and thus the expanded matrix inside the frame does not provide additional braking force for the needles during needle-punching work of the needle board .
[0028] In addition, maintenance is made much easier by a needle board that weighs up to one-eighth as much as known technology needle boards . In fact , there are numerous maintenance tasks that can be easily performed by a single operator, without the use of l i ftingequipment, like pulling out the needle board, handling it while changing needles, and reinserting it into the needle machine.
[0029] Advantageously, in possible embodiments, the holes pass through the intermediate layer with a diameter smaller than the diameter of the holes at the first and second rigid layers. Thus, an interference between the needle body and the rigid intermediate layer is achieved, such that the first and second rigid layers accurately guide the needles, while the rigid intermediate layer allows the passage of the needles and also holds the needles, due to the slight interference, so that they do not slip off or move while the needle board is being assembled .
[0030] In a possible embodiment, the first and second rigid layers are made of composite material of resin and fiber. Specifically, the fiber is selected among carbon fiber, glass fiber, aramid fiber. Thus, the first and second rigid layers are very hard and light, and able to be drilled obtaining precision holes to guide needle stems. In addition, the first layer can bear the pressure of clamping the angled needle butts by the upper plate of the moving frame.
[0031] In one possible embodiment, the first and second rigid layers and the intermediate rigid layer are held together by forces resulting from pressing and heating between 80° and 250°, preferably between 80° and 170°C.
[0032] Alternatively, in possible embodiments, the first and second rigid layers are made of HPL . Or, the first and second rigid layers can be made of metal, such as aluminum.
[0033] Preferably, in possible embodiments, the expanded material of the intermediate layer is a crosslinked expanded polymer. Advantageously, the crosslinked expanded polymer of the intermediate layer is selected among: Cross-linked expanded PVC, cross-linked expanded polyurethane, cross-linked expanded polyethylene, cross-linked expanded PET, cross-linked expanded polystyrene, cross-linked expanded polyamide, etc .
[0034] Alternatively, in possible implementations, the expanded material of the intermediate layer is a linear expanded polymer, such as expanded PVC, expanded polyurethane, expanded polyethylene, expanded PET, expanded polystyrene, expanded polyamide, preferably reinforced with fibers, e.g. carbon fibers, glass fibers, aramid fibers, etc.
[0035] In possible embodiments, the total thickness of the needle board can range from 10 to 25mm, and the thickness of the first and second rigid layers are between 0.8mm and 5mm. The thickness of the intermediate layer can be between 50% and 90% of the thickness of the needle board. Preferably, the thickness of the first and second rigid layers are between 0.9mm and 2mm.
[0036] In possible embodiments, the intermediate layer is interrupted by at least a third rigid layer. In particular, it can be interrupted by a third rigid layer or by a third and a fourth rigid layer. This solution is suitable for making very large needle boards or those with very heavy workloads.
[0037] In possible embodiments, the first rigid layer is covered with a vulcanized polymer layer. For example,the vulcani zed polymer layer is vulcani zed polyurethane or polyamide . Thi s solution prevents angled needle butts from "marking" the first rigid layer . This solution is especially suitable when the first layer is made of resin and fiber composite material , and even more particularly of resin and carbon fiber .
[0038] In possible embodiments , the second rigid layer is covered with a vulcanized polymer layer . For example , the vulcani zed polymer layer is vulcani zed polyurethane or polyamide . This solution increases the resistance on needles and protects the first rigid layer during needling processing .
[0039] In possible embodiments , both the first rigid layer and the second rigid layer are externally coated with a vulcani zed polymer layer, particularly vulcani zed polyurethane or polyamide, giving the needle board the above respective advantages .
[0040] According to another aspect of the invention, a method is provided for making a needle board comprising : prepare a first rigid layer and a second rigid layer, prepare a rigid compressive intermediate layer configured to be placed between the first and second rigid layers , the rigid compress ive intermediate layer comprising an expanded material with a density between 30 kg / m3and 900 kg / m3, preferably between 35 and 600 kg / m3, and even more preferably between 40 and 300 kg / m3, wherein the expanded material has a compressive modulus in the elastic range greater than 30 Mpa and a compressive strength greater than 400 kPa ;arrange the rigid intermediate layer with a first face adhering to the first rigid layer, a second face adhering to the second rigid layer, and free side walls facing outward, pressing the intermediate layer by compression between the first and second rigid layers , until adhesion of the intermediate layer and the first and second rigid layers is achieved, resulting in a board having a first face defined by the first rigid layer, a second face , defined by the second rigid layer, and free side walls defined by said side walls of said rigid intermediate layer ; drill through holes for inserting needles between the first and second faces .
[0041] The step of pressing to achieve adhesion of the intermediate layer and the first and second rigid layers can be done without addition of adhesives or binders , achieving adhesion by only pressing . Or, it can be done with interposition of adhesives or binders .
[0042] The pressing step to achieve adhesion of the intermediate layer and the first and second rigid layers can be done simultaneously with, or can be followed by, a heating or baking step at a predetermined temperature between 80 ° C and 250 ° C, preferably between 80 ° C and 170 ° C . This heating or baking step allows the needle board greater f irmness and strength during use , and greater cohesion between the first and second rigid layers with the intermediate rigid layer .
[0043] In possible embodiments of the method, the step of drilling through holes for the insertion of needles between the first and second faces involves the use ofdrill bits having a diameter equal to the diameter of the needle body, obtaining a diameter of the holes at the first and second rigid layers having a diameter equal to the diameter of the needle body, and obtaining a diameter of the holes at the intermediate layer with a value less than the diameter of the holes at the first and second rigid layers . In fact , the expanded material when cutting the holes has a slight springback, which allows for interference between the needle body and the rigid intermediate layer . This interference , which is present only in the intermediate layer, allows the first and second rigid layers to guide the needles accurately, while the intermediate layer allows the needles to pass through but also holds the needles , due to the slight interference , so that they do not slip or move while the needle board is being manipulated .
[0044] According to a further aspect of the invention, there is provided a needle-punching machine , comprising a movable frame configured to cause alternating motion to at least one needle board, the needle board comprising a plurality of needles mounted in arrays through respective holes in the needle board so as to be locked at a first face o f the needle board and to protrude from a second face of the needle board, the machine comprising perforated plates configured to allow a product to be needled to pass between them and to allow the needles to pass through them and through the product during alternating motion of the needle board; the movable frame by also including an upper plate , configured to removably hold the angled needle butts against the needle board,wherein the first face of the needle board is defined by a first rigid layer and the second face of the needle board is defined by a second rigid layer, wherein the needle board holes pass through the first and second rigid layers with a nominal diameter equal to the needle body diameter that the holes are configured to accommodate , wherein between the first and second rigid layers of the needle board is included a rigid compressive intermediate layer traversed by the holes , the rigid compressive intermediate layer comprising an expanded material with a density between 30 kg / m3and 900 kg / m3, preferably between 35 and 600 kg / m3, and even more preferably between 40 and 300 kg / m3, wherein the expanded material has a compressive modulus in the elastic range greater than 30 Mpa and a compressive strength greater than 400 kPa ; and wherein the rigid intermediate layer has a first face adhering to the first rigid layer, a second face adhering to the second rigid layer, and free side walls facing outward from the needle board, whereby said needle board has a first face defined by the first rigid layer, a second face , defined by the second rigid layer, and free s ide walls defined by said side walls of said intermediate rigid layer .
[0045] Such a needle-punching machine , compared to an existing needle-punching machine , has the advantage of having very light and strong needle boards , so that it requires less power to accomplish the required number of strokes / min, or to accomplish a higher number ofstrokes / min, with a same power, as well as saving energy with the same performance . It al so allows easy removal and reinsertion of the needle board during maintenance , as well as easy manipulation of the needle board, during needle replacement .
[0046] In this description, compressive modulus has been understood, as recogni zed in a standardi zed way by international systems , as the ratio of applied compressive stress to percent change in volume , in the elastic range . Also , compressive strength is the compressive stress to the point on the stress-strain curve where the material rapidly changes volume , collapsing . Both compressive modulus and compressive strength are expressed in MPa (MegaPascal ) or kPa ( kiloPascal ) .Brief description of the drawings
[0047] The present invention will now be described with reference to the attached drawings , which illustrate some non-limiting examples of its implementation, in which :- Figs . 1 and 2 show a first embodiment of a needle board structure according to the invention, without and with inserted needles , respectively;- Figs . 3 and 4 show a first embodiment of a needlepunching machine according to the invention, with a locked and unlocked needle board, respectively;- Figs . 5 and 6 show a second embodiment of a needlepunching machine according to the invention with a locked and unlocked needle board, respectively;- Figs . 7 and 8 show a second embodiment of a needle board structure according to the invention, withoutand with inserted needles, respectively;- Figs. 9 and 10 show a third embodiment of a needle board structure according to the invention, without and with inserted needles, respectively;- Figs. 11-13 show three steps of a method of producing a needle board according to the invention;- Figs. 14-15 show a fourth embodiment form of a needle board structure according to the invention;- Figs. 16-17 show a fifth embodiment form of a needle board structure according to the invention;- Figs. 18-19 show a fifth embodiment form of a needle board structure according to the invention.
[0048] The elements and features illustrated in the various embodiments, including drawings, may be combined with each other without thereby falling outside the scope of protection of the present invention as described and claimed herein.Description of preferred embodiments
[0049] With reference to Figures 1 and 2, a needle board structure 10 for a needle-punching machine 100 (see also Figs. 3-6) , has a flat shape with a predetermined thickness 11 and includes a plurality of holes 20, each designated to receive the body 31 of a needle-punching needle 30.
[0050] As is well known, a needle-punching needle 30, shown inserted into needle board 10 in Fig. 2, normally comprises an angled butt 32, and a body 31, normally cylindrical, ending in a point 33.
[0051] Needle board 10 includes:- a first face 40 configured to receive the angled butts 32 of the needles 30 at the stop ;- a second face 50 opposite the first face 40 .The first face 40 is defined by a first rigid layer 41 and the second face 50 is defined by a second rigid layer 51 .
[0052] Holes 20 pass through the first and second rigid layers 41 , 51 with a nominal diameter 24 equal to the diameter 34 of the body 31 of needles 30 that holes 20 are configured to accommodate .
[0053] Between the first and second rigid layers 41 , 51 may be included an intermediate layer 60 , which is rigid in compression and spanned by holes 20 . The intermediate layer 60 rigid in compression includes an expanded material 61 , which is rigid in compression and has a density between 30 kg / m3and 900 kg / m3, preferably between 40 and 600 kg / m3, and even more preferably between 40 and 300 kg / m3. Foam 61 has a compressive modulus in the elastic range greater than 30 MPa and a compressive strength greater than 400 kPa .
[0054] According to the invention, the intermediate rigid layer 60 has a first face 62 adhering to the first rigid layer 41 , a second face 63 adhering to the second rigid layer 51 , and free side walls 64 facing outward from the needle board 10 . Thus , the needle board 10 has a first face 40 defined by the first rigid layer 41 , a second face 50 defined by the second rigid layer 51 , and free side walls formed by the side walls 64 of the intermediate rigid layer 60 .
[0055] The total thickness 11 of the needle board can vary, in some embodiments , from 10 to 25mm, the thicknessof the first and second rigid layers can be between 0.9mm and 2mm, typically 1mm. In some embodiments, the thickness of the first and second rigid layers can be between 0.8mm and 5mm, and the thickness of the intermediate layer can be between 50% and 90% of the needle-board thickness. Needle-punching machines can use needle boards with different thicknesses, depending on the needling work to be done.
[0056] Referring to Figs. 3-6, a needle-punching machine 100 configured for needle board 10 includes, as also noted above, a moving frame 80 configured to cause alternating motion to needle board 10, according to arrow 85 in Fig. 3.
[0057] Machine 100 may include perforated plates 90, 91, with holes 92 and 93, configured to allow a product 110 to be needled to pass between them and to allow needles 30 to pass through these holes and through product 110 during the reciprocating movement of needle board 10 caused by the reciprocating movement 85 of moving frame 80, obtaining, as is known, a needled product .
[0058] The movable frame 80 may include an upper plate81 configured to removably hold the angled butts of needles 30 against needle board 10, and movable sidewalls82 with movable jaws 83 (Figs. 3 and 4) configured to removably push up the lower face 50 of needle board 10 so as to removably hold the angled butts 32 of needles 30 between needle board 10 against upper plate 81 (Fig.3) and then release the needle board 10 by lowering it downward (Fig. 4) . The movable sidewalls 82 can be moved by known pneumatic actuators not shown.
[0059] Thus, although the pressure applied to the needle board 10 between the upper plate 81 and the movable aws 83 (Fig. 3) does not result in substantial deformation of the rigid intermediate layer 60, this pressure and the fact that the side walls of the needle board 10 are formed by the free side walls 64 of the rigid intermediate layer 60 nevertheless result in minimal elastic deformation of the rigid intermediate layer 60, slightly reducing the diameter 24 of the holes 20 and thus increasing the retention of the needles 30 during needle-punching of the needle board 10. When, on the other hand, needle board 10 is not compressed (Fig. 4) and thus it can be pulled out of machine 100 for maintenance, the diameters of holes 20 of rigid intermediate layer 60 elastically return to the initial size, allowing needles 30 to be pulled out simply by operators by overcoming a slight friction.
[0060] As shown in Figs. 5 and 6, a variant of a known type of mobile frame 80, provides fixed sidewalls 82 and central screws 84 that, by engaging threaded holes 15, hold the needle board 10 against the upper plate 81 (Fig. 5) , and free it (Fig. 6) for removal of the needle board itself 10, in case of maintenance (Fig. 6) . The screws 84 engage in holes 15 drilled in the needle board 10. Instead of the jaws 83 of Figs. 3-4, in the case of Figs. 5-6 on the sides 82 there are flanges 85 that hold the needle board 10 when the screws 84 are pulled out of the holes 15 (Fig. 6) . Otherwise, the operation of the needle-punching machine of Figs. 5-6 is the same as that of the needle-punching machine of Figs. 3-4, and for simplicity its description is not repeated.
[0061] Such a needle-punching machine, either like theone shown in Figs . 3-4 and Figs . 5- 6 , or similar ones , compared to an existing needle-punching machine , has the advantage of having a very light and strong needle board 10 , so that it requires less power to accomplish the required number of strokes / min, or to accomplish a higher number of strokes / min, with the same power, as well as saving energy with a same performance . In addition, it allows for easy removal and reinsertion of needle board 10 during maintenance , as well as easy handling of needle board 10 when replacing needles 30 .
[0062] This is enabled by the structure o f needle board 10 , according to the invention, which holds without deforming, while having free side walls 64 being without a side retaining frame as US3122815 provides , the compression caused by the upper plate 81 of the movable frame 80 to hold it stationary without deforming the intermediate layer 60 , which behaves substantially like a rigid body . In fact , the expanded material 61 , with a compressive modulus in the elastic range greater than 30 Mpa, behaves substantially like a rigid material , and a compressive strength greater than 400kPa easily withstands the pressure applied to the movable frame 80 , normally not exceeding a few bars , and thus does not cause substantial deformation of the rigid intermediate layer 60 in compression, while the low density of the compression-resistant 61 expanded material allows the above-mentioned obj ects of better machine performance , lower energy consumption, and less wear to be achieved, and the free side walls 64 of the intermediate layer 60 allow very slight deformation of the diameter o f the holes 20 so as to hold the needles 30 during processing .
[0063] In addition, maintenance , in terms of pullingout the needle board, replacing needles, and reinserting the needle board 10, is made much easier by the fact that the needle board 10 weighs up to one-eighth as much as a needle board of known technique.
[0064] In a preferred form of needle board 10, holes 20 pass through intermediate layer 60 with a diameter 25 smaller than the diameter 24 of holes 20 at the first and second rigid layers 41,51. In this way, an interference between needle body 31 30 and rigid intermediate layer 60 is achieved such that the first and second rigid layers 41,51 accurately guide needles 30, while intermediate layer 60 allows needles 30 to pass through with slight interference and thus retains needles 30 so that they do not slip or move while needle board 10 is being assembled or manipulated for maintenance. Added to this is the above-described effect of slight deformation of the diameter 24 of the holes 20 during compression of the needle board 10 required during machining and achieved by the free side walls 64 of the rigid intermediate layer 60.
[0065] In possible embodiments, at least one between the first and second rigid 41.51 layer is made of material selected among: resin and fiber composite material, HPL, metal.
[0066] Specifically, at least one between the first and second rigid layer 41.51 is made of resin-fiber composite material, wherein the fiber is selected among carbon fiber, glass fiber, aramid fiber.
[0067] Thus, the first and second rigid layers 41,51 are very hard and light, and able to be drilled by obtaining precision holes 20 to guide the body 31 ofneedles 30. The first layer 41 can withstand the clamping pressure of the angled butts 32 by the upper plate 81 of the moving frame 80.
[0068] The expanded material 61 of the intermediate layer 60 can be a cross-linked expanded polymer. Specifically, the cross-linked expanded polymer of the intermediate layer 60 is selected among: Cross-linked expanded PVC, cross-linked expanded polyurethane, crosslinked expanded polyethylene, cross-linked expanded PET, cross-linked expanded polystyrene, cross-linked expanded polyamide .
[0069] Or, the expanded polymer is selected among: PVC foam, polyurethane foam, polyethylene foam, PET foam, polystyrene foam, polyamide foam, fiber reinforced, e.g. carbon fiber, glass fiber, aramid fiber. Or, expanded material 61 can be made of expanded metal, e.g. expanded aluminum, which achieves densities between 5% and 25% of compact expanded metals.
[0070] In the preferred form, cross-linked PVC foam known as Divinycell H was used, with densities from 40 to 250 kg / m3, with compressive strengths of 0.8 and 8 Mpa and compressive modulus between 50 and 350 MPa. Specifically, Divinycell HP80 was used, with density 80kg / mc, compressive strength of 0.8 Mpa and compressive modulus of 50Mpa.
[0071] In the embodiments Fig. 7 to 10, the intermediate layer 60 is interrupted by at least a third rigid layer 71; in particular, it can be interrupted by a third rigid layer 71 (Figs. 7-8) or by a third and a fourth rigid layer 71,72 (Figs. 9-10) . This solution is suitable for making very large needleboard 10 or very heavy workloads.Layers 71 or 71 and 72 are made similarly to layers 41 or 51 described above .
[0072] With reference to Figures 11- 13 , a method including the steps of :- Prepare the first rigid layer 41 and the second rigid layer 51 , prepare the intermediate layer 60 rigid compression- the compression-rigid intermediate layer 60 comprising a compression-rigid foam 61 material with a density between 30 kg / m3 and 900 kg / m3 , preferably between 35 and 600 kg / m3 , and even more preferably between 40 and 300 kg / m3 , in which the compression- rigid foam 61 material has a compressive modulus in the elastic range greater than 30 Mpa and a compressive strength greater than 400 kPa ;- Arrange the intermediate rigid layer 60 with a first face 62 adhering to the first rigid layer 41 , a second face 62 adhering to the second rigid layer 51 , and free side walls 64 facing outward,- press , as shown by arrows in Fig . 12 , the rigid intermediate layer 60 by compression between the first and second rigid layers 41 , 51 , until adhesion of the intermediate layer 60 and the first and second rigid layers 41 , 51 is achieved, resulting in a board having a first face 40 defined by the first rigid layer 41 , and a second face 50 , defined by the second rigid layer 51 and free side walls coincident with the free side walls 64 of the rigid intermediate layer 60 ;- Drill through holes 20 ( Fig . 13 ) for inserting needles 30 between the first face 40 and the second face 50 .
[0073] In particular, the adhesion of the intermediate layer 60 and the first and second rigid layers 41,51 is obtained by high-pressure pressing, such as in a press, without interposition of adhesives. Alternatively, the adhesion of the intermediate layer 60 and the first and second rigid layers 41.51 is obtained by interposition of adhesives and pressing.
[0074] The pressing step to achieve adhesion of the intermediate rigid layer 60 and the first and second rigid layers 41,51 may be done simultaneously with, or may be followed by, a heating or baking step at a predetermined temperature between 80° and 250°, preferably between 80° and 170°. In the case of Divinycell H cross-linked PVC, a baking temperature between 110° and 140°C was used. This heating or baking step allows the needle board 10 greater compactness and strength during use, and greater cohesion between the first and second rigid 41.51 layers with the intermediate rigid 60 layer.
[0075] As per Fig. 13, the step of drilling the through holes 20 for the insertion of needles 30 between the first and second faces 31,41 involves the use of drill bits 120 having a diameter 124 equal to the diameter 31 of the needle body 31, obtaining a diameter 24 of the holes at the first and second rigid layers 41,51 equal precisely to the diameter of the needle body 31, and obtaining a diameter 25 of the holes 20 at the rigid intermediate layer 60 with a value less than the diameter 24 of the holes at the first and second rigid layers 41,51. In fact, the expanded material 61, when drilling the holes 20, exhibits a slight springback, which allows for interference between the needle body 31 and the rigidintermediate layer 60. This interference, which is only present in the intermediate layer, allows the first and second rigid layers 41,51 (Fig. 2, Fig. 8, Fig. 10) ) to accurately guide the needles 30, while the intermediate layer allows the needles 30 to pass through but also allows it to hold the body 31 of the needles 30, due to the slight interference due to the diameter 25, which is slightly smaller than the diameter 24, so that they do not slip or move while the needle board 10 is being manipulated .
[0076] Referring to Figures 14 and 15, in possible embodiments the first rigid layer 41 is covered with a vulcanized polymer layer 45. For example, the vulcanized polymer layer 45 is vulcanized polyurethane or polyamide. This solution prevents the angled butts 32 of the needles 30 from "marking" the first rigid layer 41 when they are pressed by the upper plate 81 of the needle-punching machine (Figs. 3, 5) . This solution is particularly suitable when the first rigid layer 41 is made of resin and fiber composite material, and even more particularly of resin and carbon fiber, which is highly strong and light, but brittle under concentrated loads.
[0077] Referring to Figures 16 and 17, in a possible embodiment of the invention, the second rigid layer 51 is covered with a vulcanized polymer layer 55. For example, the vulcanized polymer layer 55 is vulcanized polyurethane or polyamide. This solution increases the resistance on the needles and protects the first rigid layer 51 during needling processing, and during assembly / disassembly, and avoids "marking" by the jaws 83 (Figs . 3,5) .
[0078] With reference to Figs. 18 and 19, in possible embodiments of the invention, both the first rigid layer 41 and the second rigid layer 51 are externally coated with a vulcanized polymer layer 45 and 72, respectively, specifically polyurethane or vulcanized polyamide, giving the needle board the respective advantages described above with reference to Figs. 14-15 and 16-17.
[0079] The same description already made for all three embodiments in Figs. 14-19 applies to all other embodiments described and illustrated above, where applicable, and vice-versa, so its repetition is omitted for simplicity.
[0080] The invention thus conceived is susceptible to numerous modifications and variations, without departing from the scope of protection defined by the claims. In addition, all details are substitutable by other technically equivalent elements. Virtually all materials used and dimensions can vary as needed.
[0081] The above description of embodiments of the invention is capable of showing the invention from the conceptual point of view in such a way that others, using the known technique, will be able to modify and / or adapt in various applications such specific embodiments without further research and without departing from the inventive concept, and, therefore, it is understood that such adaptations and modifications will be considered as equivalents of the specific embodiments. The means and materials for realizing the various functions described may be of various kinds without departing from the scope of the invention. It is understood that the expressions or terminology used are for descriptive objects onlyand, therefore, not limiting.
Claims
CLAIMS1. A needle board structure (10) for needle-punching machines (100) , said needle board (10) having a flat shape with a predetermined thickness (11) and comprising a plurality of holes (20) each designated to receive the body (31) of a needle (30) for needling, said needle board (10) further comprising:- a first face (40) configured to receive angled butts (32) of said needles (30) at the stop;- a second face (50) opposite the first face (40) , wherein said first face (40) is defined by a first rigid layer (41) and said second face (50) is defined by a second rigid layer (51) , wherein said holes (20) pass through said first and second rigid layers (41,51) with a nominal diameter (24) equal to the diameter (34) of the body (31) of the needles (30) that said holes (20) are configured to accommodate, wherein between said first and second rigid layers (41,51) there is included a rigid intermediate layer (60) which is compression-rigid and is traversed by said holes (20) , said rigid intermediate layer (60) comprising a compression- rigid expanded material (61) having a density between 30 kg / m3and 900 kg / m3, preferably between 35 and 600 kg / m3, and even more preferably between 40 and 300 kg / m3, wherein said expanded material (61) has a compressive modulus in the elastic range greater than 30 MPa and a compressive strength greater than 400 kPa;and wherein the intermediate rigid layer (60) has a first face (62) adhering to the first rigid layer (41) , a second face (62) adhering to the second rigid layer (51) , and free side walls (64) facing outward from the needle board (10) , whereby said needle board (10) has a first face defined by the first rigid layer (51) , a second face, defined by the second rigid layer (52) , and free side walls defined by said side walls (64) of said intermediate rigid layer (60) .
2. Structure of needle board (10) according to claim 1, wherein said holes (20) are configured to pass through said rigid intermediate layer (60) with a diameter (25) smaller than the diameter (24) of said holes (20) at the first and second rigid layers (41,51) .
3. Structure of needle board (10) according to any of the previous claims, wherein at least one between the first and second rigid layers (41,51) is made of material selected among: composite material of resin and fiber, in HPL, of metal.
4. Needle board structure (10) according to any of the previous claims, wherein at least one between the first and second rigid layers (41,51) is made of resin-fiber composite material, wherein the fiber is selected among carbon fiber, glass fiber, aramid fiber.
5. Needle board structure (10) according to any of the previous claims, wherein the expanded material of the rigid intermediate layer (60) is a cross-linked expanded polymer.
6. Needle board structure (10) according to claim 5, wherein the cross-linked expanded polymer of the rigidintermediate layer (60) is selected among: crosslinked expanded PVC, cross-linked expanded polyurethane, cross-linked expanded polyethylene, cross-linked expanded PET, cross-linked expanded polystyrene, cross-linked expanded polyamide.
7. Needle board structure (10) according to any of the previous claims, wherein the expanded material of the rigid intermediate layer (60) is an expanded metal, especially an expanded aluminum alloy.
8. Needle board structure (10) according to any of the previous claims, wherein the rigid intermediate layer (60) is interrupted by at least a third rigid layer (71) , in particular it can be interrupted by a third rigid layer (71) or by a third and a fourth rigid layer (71,72) .
9. Needle board structure (10) according to any of the previous claims, wherein said first and second rigid layers (41, 51) and said intermediate rigid layer (60) are held together by forces resulting from pressing and heating between 80° and 250°, preferably between 80° and 170 °C.
10. Structure of needle board (10) according to any of the previous claims, wherein said needle board (10) has said first rigid layer (41) externally coated with a first vulcanized polymer layer (45) .
11. Structure of needle board (10) according to any of the previous claims, wherein said needle board (10) has said second rigid layer (51) externally coated with a second vulcanized polymer layer (55) .
12. Structure of needle board (10) according to any of the previous claims, wherein said needle board (10) hassaid first rigid layer (41) coated externally with a first vulcanized polymer layer (45) and said second rigid layer (51) coated externally with a second vulcanized polymer layer (55) .
13. A method for making a needle board (10) including:- Prepare a first rigid layer (41) and a second rigid layer ( 51 ) ,- Prepare a compression-rigid intermediate layer (60) between said first and second rigid layers (41,51) , said compression-rigid intermediate layer (60) comprising a compression-rigid expanded material (61) with a density between 30 and 900 kg / m3, preferably between 35 and 600 kg / m3, and even more preferably between 40 and 300 kg / m3, wherein said compression-rigid expanded material (61) has a compressive modulus in the elastic range greater than 30 Mpa and a compressive strength greater than 400 kPa;- arrange said intermediate rigid layer (60) with a first face (62) adhering to the first rigid layer (41) , a second face (62) adhering to the second rigid layer (51) , and free side walls (64) facing outward,- press the rigid intermediate layer (60) rigid in compression between said first and second rigid layers (41,51) , until adhesion of said rigid intermediate layer (60) and said first and second rigid layers (41,51) is achieved, resulting in a needle board (10) having a first face (40) defined by said first rigid layer (41) , a second face (50) defined by said second rigid layer (51) and side walls defined by said free side walls (64) of said intermediate rigid layer (60) ;drill through holes (20) for inserting needles (30) between said first and second faces (40,50) .
14. The method for making a needle board (10) according to claim 13, wherein said adhesion of said rigid intermediate layer (60) and said first and second rigid layers (41,51) is achieved by high-pressure pressing, without interposition of adhesives, in particular there being provided a heating or baking step of said needle board (10) during or after said pressing step at a predetermined temperature between 80°C and 250°C, preferably between 80°C and 170°C.
15. A needle-punching machine (100) , comprising a movable frame (80) configured to cause an alternating motion to at least one needle board (10) , said needle board (10) comprising a plurality of needles (30) mounted in arrays through respective holes (20) of the needle board (10) so as to be locked at a first face (40) of the needle board and to protrude from a second face (50) of the needle board (10) , said machine (100) comprising perforated plates (90, 91) configured to allow a product (110) to be needled to pass between them and to allow the needles (30) to pass through them and through the product (110) during the alternating movement of the needle board (10) ; said movable frame (80) comprising an upper plate (81) , configured to keep the angled butts (32) of the needles (30) removably pressed against said needle board (10) , and movable side flanks (82) with movable jaws (83) configured to removably push upward the second face (50) of the needle board (10) so as to keep the needle board (10) removably pressed against the upper plate (81) ,wherein said first face (40) of said needle board (10) is defined by a first rigid layer (41) and said second face (50) of said needle board (10) is defined by a second rigid layer (51) , wherein said holes (20) of said needle board (10) pass through said first and second rigid layers (41,51) with a nominal diameter (24) equal to the diameter of the needle body (31) that said holes (20) are configured to accommodate, wherein between said first and second rigid layers (41,51) of said needle board (10) there is included an rigid intermediate layer (60) which is compression-rigid and is passed through said holes (20) , said rigid intermediate layer (60) comprising a compression-rigid expanded material (61) with density between 30 kg / m3and 900 kg / m3, preferably between 35 and 600 kg / m3, and even more preferably between 40 and 300 kg / m3, wherein said compression- rigid expanded material (61) has a compressive modulus in the elastic range greater than 30 MPa and a compressive strength greater than 400 kPa; and wherein the intermediate rigid layer (60) has a first face (62) adhering to the first rigid layer (41) , a second face (63) adhering to the second rigid layer (51) , and free side walls (64) facing outward from the needle board (10) , whereby said needle board (10) has a first face (40) defined by the first rigid layer (41) , a second face (50) , defined by the second rigid layer (51) and side walls defined by said free side walls (64) of said intermediate rigid layer (60) .