JP2005514222A - Flexible energy absorbing material and manufacturing method thereof - Google Patents

Abstract

  A flexible energy absorbing sheet material comprising a dilatant material (6) impregnated in or supported by an elastic carrier (1). The dilatant material remains soft until subjected to an impact, upon which the properties change and become temporarily rigid, after which the material returns to its normal flexible state. The carrier can be a spacer fabric, a foam layer, or a module or yarn of dilatant material housed between a pair of spaced apart layers. A method for producing an energy absorbing sheet is also disclosed.

Description

  The present invention relates to a preferable sheet-like flexible energy absorbing material and a method for producing the same.

  Known impact protection solutions currently available tend to fall into two categories. That is, a rigid outline (eg, roller blades or skateboard knee or elbow pads) that can be uncomfortable to wear, or a foam or foam laminate pad (eg, an insert for ski clothing) that provides a low level of protection. It is.

  Thus providing an energy absorber that is lightweight and flexible and therefore can be worn comfortably while still dissipating and absorbing the impact applied to it, thereby achieving effective protection for the wearer There is a need to.

  In my previously published UK patent application No. 2349798, I described a protective member that uses an energy absorber that remains soft and flexible until subjected to an impact, but becomes rigid upon impact. And billing. The material is encapsulated in a flexible sealing envelope formed with one or more wraps each having a vertex directed in the direction of impact, thereby making the material rigid. Sometimes the impact force applied to it or the apex is absorbed.

  A suitable energy absorber is a dilatant material that behaves like a fluid when soft. Therefore, in order to be able to use it as a protective member, it is necessary to accommodate in a sealed flexible jacket. For example, when the jacket is accidentally broken, the dilatant material leaks from the breakage hole of the jacket. Due to the need for hermetic jackets, the protective members can be expensive to manufacture and they must be user specific, so a dedicated molding process is required to manufacture them.

  Accordingly, the object of the present invention is to easily mold a dilatant material into a product that does not need to be contained in a flexible hermetic envelope and can be used for various energy absorption applications, or It is to provide a flexible energy absorbing material and a method for producing the same that can be molded in other ways.

  A further object of the present invention is to provide a method for producing the flexible protective material described above.

  In one aspect of the present invention, an elastic carrier having pores or cavities that is soft and flexible until subjected to an impact, and its properties change to become temporarily stiff upon impact, after the impact A flexible energy absorbing sheet material comprising the carrier coated or impregnated with a material that returns to its normal flexible state is provided.

  A preferred material is a dilatant compound. The carrier can be a spacer material.

  In one embodiment, the elastic carrier consists of an elastic core sandwiched between a pair of coating layers. The elastic core can consist of a layer of yarn, and the covering layer has a number of openings in it that can be hexagonal, diamond-shaped, or any other suitable shape.

  The elastic carrier can be braided or woven into a resilient pile. The yarn is preferably between 0.05 and 1 mm in diameter. The yarn can be a single fiber or a multifilament yarn.

  The outer surface of each covering layer can be formed thereon with a plurality of compressible bubbles.

  The compressible core can be formed with elongated hollow channels that can be tubular and parallel to each other.

  Holes can be formed in the sheet material to reduce its mass.

  The elastic carrier can be made from a foam material which is preferably an open cell foam.

  However, the elastic carrier can be a fleece material or a Scotch Bright (3M trademark) material.

  In another aspect of the present invention, a flexible energy absorbing sheet material is provided that includes an elastic core of an individual module made from a dilatant compound sandwiched between a pair of coating layers. The modules can be disposed within the compressible core randomly or on an axially aligned row across the width of the sheet.

  Alternatively, the module can be composed of parallel elongated hollow tubular members in the covering layer.

  Each module can have a coating layer on it that can be made from another material, or it can be a hard skin of the dilatant material.

  The module can be spherical and is preferably hollow. The hollow center can be filled with a lightweight elastic filler such as a duolite sphere.

  In another aspect of the invention, an energy absorbing sheet material is provided that includes yarn formed from a dilatant compound that is woven or braided into a compressible layer.

  Preferably, the compressible layer is contained between a pair of spaced sheet-like supports, the thread having a covering layer thereon, which is a harder skin of the dilatant compound, Or it can be a separate layer.

  The yarn can be hollow.

  One of the covering layers can be a woven material containing a polycyclic aromatic amide yarn. The other coating layer can be a textile layer. However, the two covering layers can be made from the same material.

  The dilatant compound is preferably a dimethylsiloxane hydroterminated polymer.

  The dilatant compound can include lightweight fillers such as duolite spheres therein.

  A preferred dilatant compound is Dow Corning 3179.

  The present invention will now be described by way of example only with reference to the accompanying drawings.

  Referring now to FIG. 1, there is shown one form of carrier 1 that can be used to form the flexible energy absorbing sheet material of the present invention. The carrier 1 includes a ribbed material 2 sandwiched between and joined to an upper sheet 3 and a lower sheet 4. These sheets can be made from any suitable material, but are preferably formed from a woven material on which a surface treatment or coating can be applied. The coating is provided not on the ribbed material 2 but on the outer surface of each sheet 3 or 4 and can be a waterproof coating. Between each of the ridges extending in the longitudinal direction, spaces or pores 5 are formed for reasons described later in this document.

  Referring now to FIG. 2, it can be seen that the space 5 has been filled with the energy absorbing dilatant compound 6 leaving the inner hollow core 7. These hollow cores can be left empty or they can be filled with low density materials such as duolite spheres or other suitable low weight fillers, which add elasticity to the entire carrier 1 And helps maintain the energy absorbing dilatant compound 6 in its predetermined shape shown in FIG.

  FIG. 3 shows a corner portion of an alternative embodiment of the flexible energy absorbing sheet material of the present invention. The core 9 is preferably made from an open-cell foam type, such as cellulose, polyurethane, or silicone foam. The cell can be made larger or smaller depending on the end use of the material. The foam core 9 is dipped in an aqueous solution of energy absorbing dilatant compound 6 in the manner described later in this document and then dried, leaving a foam impregnated with energy absorbing material 6 in the pores or cavities therein. . The impregnated core 9 can then be immersed in a bath of protective material such as silicon rubber to form a protective layer or coating layer 8 thereon.

  FIG. 4 shows an alternative form of energy absorbing sheet to that shown in FIG. 3 (only its corner portion is shown). This foamed sheet is the same as that shown in FIG. 3 except that through-holes 10 are formed in it. These holes 10 are formed in the foam before the energy absorbing dilatant compound 6 is introduced into it and before the protective layer 8 is applied to them. These holes 10 help to reduce the weight of the energy absorbing sheet material and also provide greater elasticity to the foam material for repeated energy absorption.

  FIG. 5 is a perspective view of another form of carrier that can be used to make the energy absorbing sheet material of the present invention. The carrier 11 includes an elastic partition 12 sandwiched between and joined to the upper sheet 13 and the lower sheet 14. Sheets 12 and 13 can be made from any suitable material (preferably a woven fabric), and the outer surface can have a surface treatment or coating thereon, such as a waterproof coating thereon. The elastic partition 12 separates the upper sheet 13 from the lower sheet 14, and a gap or gap 15 is formed between them. Although the dividers 12 are illustrated as solid in FIG. 5, they can have holes formed therein. The dividers 12 can be made from any suitable material, but their primary function is to control the distance between the upper and lower sheets 13 and 14 that are spaced apart. They can be attached to the upper and lower sheets, perpendicular to them as shown, or diagonally. The partitions are preferably the same size, but can be of different lengths so that the distance between the spaced sheets 13 and 14 changes.

  FIG. 6 shows the carrier shown in FIG. 5, but with the gap 15 filled with energy absorbing dilatant compound 16 leaving a hollow core 17. They are filled with a lightweight material, such as a duolite sphere, or other lightweight filler that helps add elasticity to the carrier material and also helps maintain the energy absorbing dilatant compound in the defined shape illustrated. be able to. The whole can be covered with the liquid energy absorber 16 so that the hollow core 17 is left only in its protective skin.

  The spaced sheets 3, 4 or 13, 14 can be made from any flexible material, such as a thin silicone sheet or woven material. The spaced sheets need not be made from the same material. For example, the top sheet can be made from a clogged woven material containing a polycyclic aromatic amide yarn such as Kevlar for abrasion resistance. The top sheet can also be coated with a weatherable film or polyurethane that encapsulates the energy absorbing dilatant compound 6. The lower sheet can also be a woven material that can be a different material than the upper sheet. As an example, the lower sheet can be a wicking microfiber with a fluffed surface so that it is comfortable for the wearer.

  Although the present invention has been described with reference to sheet material, it uses bag weaving techniques by joining two opposing edges of a rectangular sheet together or, for example, as used in the manufacture of socks or stockings. By doing so, it can be manufactured in a tubular shape. The tube can be tapered, for example when it is worn as a leg armor.

  The flexible energy absorbing sheet of the present invention can vary in thickness, thereby placing thinner portions in areas where minimal impact protection is required, while more where it requires maximum impact protection. It becomes possible to arrange a thick part. In the case of leg armor, the thinner area would be the entire back of the leg and the thicker area would be the front of the knee, thigh, or shin. Armor can also have multiple layers.

  Referring now to FIG. 7, both are known as “hexagonal” spacer materials, including a fabric layer 19 sandwiched between an upper layer 20 and a lower layer 21 with hexagonal openings 22 formed therein. Another form of carrier is shown. The side of each hexagonal opening 22 of the upper sheet 20 is connected to the side of the hexagonal opening of the lower sheet 21 located immediately below it by a plurality of threads 19a, giving the central layer a cellular configuration. Individual yarns 19b also extend through each cell as shown. This spacer material is NO. Available from Scott and Fife as 90.042.002.00.

  Another carrier 25 is shown in FIG. 8 and it can be seen that it includes a fabric upper layer 27 and a fabric lower layer 28 with a spacer layer 26 including a plurality of threads 26a sandwiched therebetween. A hemispherical bubble 29 is formed on the upper surface 27 and the lower surface 28, which can be axially aligned or offset as shown.

  FIG. 9 shows another form of carrier that includes upper and lower fabric layers 32 and 33 having a number of pockets 31 formed therein by stitches 31a. The pockets 31 are filled with yarns or fibers 34 that can be impregnated with a dilatant compound or extruded (or coated or filled) from a dilatant material.

  To form the energy absorbing sheet material of the present invention using the carrier shown in FIGS. 7 and 8, the gap between the yarns 19a, 19b, or 26a is associated with the embodiment shown in FIGS. The dilatant compound is impregnated and filled in the manner already described. As a result, the hexagonal material of FIG. 7 including the warp yarn 19a and the weft yarn 19b is coated with the dilatant compound, leaving a space in the material at each hexagonal hole. In the case of the carrier shown in FIG. 8, the bubble 29 and the yarn 26a between them are filled with a dilatant compound, and the carrier and the soft dilatant compound are compressible upon impact, and the impact causes the soft dilatant material to become rigid and impact. The elastic carrier helps the dilatant compound return to its original configuration after impact.

  From the foregoing, it will be understood that each flexible energy absorbing sheet material described and illustrated includes a carrier having pores impregnated or filled with an energy absorbing dilatant compound. Thus, since the elastic carrier supports the dilatant compound, it is no longer necessary to house it in a sealing envelope as disclosed in my previous patent.

  A suitable energy absorbing material is a dilatant compound that remains soft and flexible until subjected to an impact, and changes its properties and becomes rigid temporarily upon impact. The material thus returns to its normal flexible state after impact. Suitable energy absorbers are strain rate sensitive materials such as dilatant compounds whose mechanical properties change upon impact. A preferred material is a dimethylsiloxane hydroterminated polymer such as Dow Corning 3179 material, or a lighter version incorporating duolite spheres or derivatives thereof.

  The carrier can be coated or impregnated with the dilatant compound in various ways. This can be done by heating the composite to more easily flow into the gap or pore. It is preferred to press fit into the pores, but it can be pumped into them or sucked in using a vacuum.

  Alternatively, the dilatant compound can be diluted to reduce its viscosity to the point where it easily flows. Any suitable diluent can be used, but solvents that can be subsequently removed without adversely affecting the energy absorbing properties of the dilatant compound are preferred. After diluting the dilatant compound, the dilatant compound remains but the solvent evaporates. Examples of suitable solvents used individually or in admixture are propanol, methanol, dichloromethane, and trichloromethane.

  When the energy absorber or dilatant compound is thinned, it can be more easily transferred into the carrier gap. The carrier can be of the various types described above. When incorporated into a foam carrier, it is necessary to use a low viscosity mixture of solvent and energy absorbing dilatant material. To achieve this, the foam needs to be compressed and expanded so that the low viscosity dilatant compound is drawn into the foam and fully entrained in the cells therein. After the gap in the carrier is filled, partially filled, or coated with the dilatant compound, heat, vacuum, or other suitable method is used to completely dry the solution and drive off the solvent.

  When polyurethane foam is used as the carrier, the dilatant compound can be pushed into it, squeezed into it, pumped, or otherwise incorporated. If the foam is a large open cell constituent, this becomes easier and heat is applied. This is an open-cell foam and is a Dow Corning dilatant material no. 3179 was performed at 150 ° C. Cellulose foam has also been found to make excellent carriers due to its high absorbent quality.

After removing the solvent, the volume of the dilatant energy absorber is potentially reduced. Thus, the carrier cover sheet can be pre-stretched if necessary before the energy absorber is inserted into the cavity. After the solvent is expelled or the energy absorber is completely dried, the cover sheet can be released, thus adapting to changes in the volume of the energy absorber due to evaporation of the solvent.

  The viscosity of the dilatant material / solvent mixture can be reduced to a correction amount so that the required coating / penetration of the carrier material takes place. Since the use of a solvent can be expensive, other methods for impregnating the carrier, such as heating the dilatant material, can be used to reduce its viscosity.

  An alternative method is to make the dilatant material into an emulsion form. The components of the dilatant compound are first made into an emulsion. These parts are then mixed / reacted to form an emulsion of the dilatant material. The proportion of water is selected to ensure an emulsion of the proper viscosity to coat / impregnate the carrier. Any other standard technique for forming an emulsion can also be used. The emulsion can contain all other additives used in the lightweight version. Solvents can be used to help stabilize the emulsion.

  The advantage of an emulsion is that the dilatant material can be handled more easily and less specialized equipment is required so that the impregnation can be carried out at the energy absorbing sheet manufacturer's factory. The manufacturer simply adds the emulsion to the carrier material and drives off the water by any suitable method, thereby leaving the impregnated sheet material of the present invention.

  By way of example only, a standard mountaineering fleece jacket can be easily modified to include a protective area using an emulsion. The mask can be stripped and the emulsion applied by any suitable method in the area of the jacket that needs protection. When dried, the product can have protection where the dilatant material in the carrier remains. Emulsions can also be used to achieve impregnation of parts made with existing processes.

  Many automobile dashboards or automobile bumpers are lined with foam. Therefore, this foam can be used as a carrier material, and an emulsion can be applied to the foam. It can be pumped or introduced in any other suitable manner. Therefore, the present invention can be applied to many existing parts without requiring a complete design change.

  Different types of energy absorbing sheet material comprising individual modules of energy absorbing material sandwiched between an upper sheet and a lower sheet are shown in FIGS.

  FIG. 10 is a cross-sectional view of the extruded fiber of the energy absorbing dilatant compound 36. Although the extrudate is illustrated as a circle, other shapes such as an ellipse, rectangle, star, or triangle can be readily formed. The energy absorbing material 36 is encapsulated in a covering layer 37, which can be a skin formed from the same material as the core 36, or it can be a different material. The extruded length of material can then be traversed to form individual modules or segments.

  The energy absorber can be extruded as a hollow tube, which is then cut to the required length.

  However, the module can be spherical and the energy absorbing material can be dripped from the container to form a sphere. They can form a full skin when exposed to appropriate conditions, just as the full skin is formed when the open container paint is exposed to air. Accordingly, each module is composed of an energy absorbing material encapsulated in a thin shell of the same material.

  A further method of generating the module is to encapsulate the energy absorber in a suitable encapsulant that can be sprayed onto the module. This can be done while the modules fall from their original forming machine or when the extrudate exits the extruder. As an alternative to spraying, the module can be coated within the encapsulant by completely immersing it in a bath of encapsulant. Alternatively, the module can be coated using powder coating, which is then heated rapidly to encapsulate the encapsulating layer in a manner similar to powder coating technology or any other suitable technology. Can be formed.

  After the modules are formed, they can be placed on the energy absorbing sheet, for example, as shown in FIGS. Referring initially to FIG. 11, a sheet 40 is shown that includes a number of dilatant compound spheres 41 sandwiched between an upper sheet 42 and a lower sheet 43. The spheres 41 are randomly arranged.

  The energy absorbing sheet 40A shown in FIG. 12 is the same as that shown in FIG. 11 except that the dilatant compound spheres 41 are arranged in a straight line between the upper sheet 42 and the lower sheet 43. The configuration is virtually the same.

  In the embodiment shown in FIG. 13, the energy absorbing sheet 40B uses a plurality of larger hollow modules 41 of dilatant compounds (preferably extruded) disposed between the upper sheet 42 and the lower sheet 43. Formed. The interior of the modules 41 can be filled with a gas at atmospheric pressure or higher to increase their elasticity. Alternatively, the module may be a lightweight hollow ball coated with a dilatant compound and, if necessary, a suitable skin. The hollow center of the ball provides resilience that allows the outer skin of the dilatant material to repel after impact and return to its original shape. The hollow spheres can be filled with lightweight materials to assist in returning them to their original configuration after absorbing the impact. Alternatively, these hollow spheres can be placed in a sheet as shown in FIG. 3 or in the center of a “thermotex” type sheet as shown in FIG.

  The energy absorbing sheet including the module of the dilatant compound shown in FIGS. 10 to 13 remains soft and flexible until subjected to an impact, changes its properties upon impact, becomes temporarily rigid, The module returns to its normal flexible state.

  The energy absorbing dilatant compound in the module absorbs the impact force during impact and diffuses the addition. A suitable material is a dimethylsiloxane hydroterminated polymer such as the material sold by Dow Corning under catalog number 3179 or its lightweight version including duolite spheres.

  Referring now to FIGS. 14-16, there are shown threads that can be used to form the energy absorbing sheet material of the present invention. Referring initially to FIG. 14, an extrudate 50 is shown that includes a tubular core 51 made from an energy absorbing material. This is extruded as a long object. The core 51 is enclosed in its own skin 52.

  An alternative form of thread 50A is shown in FIG. It is virtually identical to that shown in FIG. 14 except that the skin 52 is much thicker. The covering 52 can be made of a material different from that of the core 51.

  FIG. 16 shows a further alternative yarn 50B. It is an extruded tubular member 56 having a hollow center core 57 made from an energy absorbing material.

  Any suitable method of making the yarn or fiber can be used. These include extrusion, coextrusion, extrusion and coating, or pultrusion. As an alternative to the yarn shown in FIG. 16, the tubular member 50B can be made from any energy absorbing material around the central core of another material. This other material can be a thread or fiber formed using any suitable process. By way of example only, the center fiber can be drawn through a bath of energy absorber, which then forms a coating 50B. This can be a pultrusion technique. The central core provides additional tensile strength and helps to prevent the finished yarn from overstretching or breaking.

  17 and 18 show two alternative ways in which the energy absorbing yarns shown in FIGS. 14-16 can be used to form the energy absorbing sheet of the present invention. First, referring to FIG. 17, it can be seen that a large number of yarns 61 as shown in FIGS. 14 to 16 are sandwiched between the upper sheet 62 and the lower sheet 63. The yarn is formed in a zigzag shape as shown only in the weft direction. In another embodiment, they can be arranged in both the warp and weft directions. The sheets 62 and 63 are preferably formed from a woven material and adhered to the energy absorbing material thread 61.

  FIG. 18 shows an alternative form of energy absorption made using a coil-shaped energy absorbing yarn sandwiched between an upper sheet 62 and a lower sheet 63, as shown in FIGS. Indicates a sheet. Although the coils 61 are shown only in the weft direction, in other embodiments they can be in both the warp and weft directions. The sheets 62 and 63 attached to the coil 61 are preferably made from a woven material.

  The energy absorbing material in the yarn 61 absorbs the impact force during the impact and diffuses the load. The energy absorbing material in the coextruded product is preferably a strain rate sensitive material such as a dilatant compound whose mechanical properties change upon impact. A suitable material would be a lightweight version of strain rate sensitive material including duolite spheres. A suitable material is No. 1 by Dow Corning. A dimethylsiloxane hydroterminated polymer such as the material sold as 3179 or a lightweight version thereof.

  The extruded or co-extruded material 61 is preferably not encapsulated and contained by its own skin formed by exposing the raw modified dilatant material to the proper conditions. For example, the material is exposed to air or it is immersed in another material or it is exposed to ultraviolet light, thus forming an outer skin. It is known that a class of silicon compounds forms the outer skin but the core remains flexible. An example of this would be a standard silicon encapsulant.

  FIG. 19 shows one method of producing the energy absorbing sheet material of the present invention using a machine or roll mill having a pair of spaced apart (normally heated) rollers 70 and 71. Two layers of carrier material 72 and 73 as shown in FIGS. 1-9 are fed between rollers 70 and 71, while one layer of dilatant compound 74 is also between rollers 70 and 71 and between layers 72 and 73. Sent. The roller presses the dilatant compound 74 into the carrier layers 72 and 73. “X” indicates the degree of tightening at which the two layers 72 and 73 are compressed together. Note that the sheet 75 formed by impregnating the dilatant compound 74 emerging from the rollers 70 and 71 returns to its normal thickness.

  Another set of rollers (not shown) can be provided downstream of the first set to further apply pressure to the sheet 75 if necessary to help force the dilatant material 74 into it. The dilatant material helps to hold the two sheets 72 and 73 together.

  FIG. 20 illustrates a method of manufacturing the energy absorbing sheet 75 of the present invention in which spheres 76 are additionally introduced into the layer of dilatant compound 74 that is fed between rollers 70 and 71. These spheres 76 provide additional elasticity to the finished sheet material 75 emerging from the downstream side of the rollers 70 and 71. Otherwise, the manufacturing method is the same as described in connection with FIG.

  Referring now to FIGS. 21 and 22 of the drawings, there is shown an elbow pad 80 thermoformed from a spacer material filled with a dilatant material. The molded pad 80 has a number of vertices 81 along its length that help to increase comfort and flexibility. The apex 81 also serves to absorb and disperse impact energy.

  However, the pad 80 can be molded from a foam material as shown in FIGS.

  The pad thickness can be varied to provide greater protection where needed. For example, from FIG. 22, the upper region 82 is thicker than the lower region 83, which helps distribute the load away from the wearer's bone close to the surface.

  In order to manufacture the pad shown in FIGS. 21 and 22, for example, a sheet-like spacer material as shown in FIG. 1 or 5 is inserted into the mold in a raw state. The material is then heat cured (usually at about 150 ° C.). After about 5 minutes it is removed from the mold and allowed to cool. A “thermoset” material maintains its molded shape and has the required level of elasticity. Thereafter, the dilatant material is integrated or impregnated into the shaped shape in the manner already described.

  An alternative method of producing a molded part as shown in FIG. 21 is to place the carrier fibers and dilatant compound in a heated mold, which is then closed and compressed. After a few minutes, the dilatant compound flows to the appropriate area of the mold and the carrier material is also “thermoset”. After the molded part has been removed from the mold and allowed to cool, it can then be finished for the necessary post-trimming or coating preparation. This process is particularly suitable for producing more complex molded articles. Note that the three-dimensional shape and thickness can vary depending on its end use. The cost of a single hot press process provides significant cost savings over other armor examples that require one or more injection molded parts and subsequent assembly thereof.

  If a smaller amount of dilatant material is placed in the mold using the same hot press manufacturing method, it will not impregnate the entire part being molded. In this way, only the “thick” central upper part 82 can be impregnated. The non-impregnated portion of the carrier material can then be used to attach the molded armor to the garment. A further derivative of this technique can be used to change the quality of the dilatant compound of the molded armor. For example, a much lighter dilatant compound can be used for the majority of armor than is used for the critical central portion or just above the elbow joint. In this way, the same mold can be modified to suit various applications. A further manufacturing method is to inject dilatant material.

  The method described above can also be used for multilayer carrier materials or for backing foam or hexagonal spacer materials as shown in FIG.

Test results:
When subjected to European Motorcycle CE Standard Test No. EN1621, the above thermoset product sample shown in FIGS. 21 and 22 achieved a result of 16.2 Kn. As a comparison, a completely encapsulated injection molded part of the same shape achieved 10 Kn.

  FIG. 23 is a cross-sectional view of a known bulletproof garment including a hard shell 90 having a foam backing 91. An insert 92 made from the energy absorbing material of the present invention is inserted into a pocket 93 between the shell 90 and the foam backing 91. Thus, the sheet material of the present invention can be used to help enhance the performance of existing armor, thus avoiding the need for complete design changes. The insert can be cut into any desired shape to facilitate the process of fitting to existing armor. Inserts can be easily incorporated into existing products during assembly. These simple inserts have shown significant impact performance improvements.

Test results:
Tests were conducted by SATRA in Kettering, UK, using European motorcycle CE standard test No. EN1621, using a 50 joule energy, 5 kg mass, and a 50 mm radius mandrel (CE pass level is 35 Kn).
1) Dainese elbow armor 22.5Kn
2) Dainese elbow armor and insert A 16Kn
3) K2 elbow armor 23.4Kn
4) K2 elbow armor and insert A 17.2Kn

  Insert A is a Dow Corning dilatant material no. No. 3 made by Scott and Fife, impregnated with 3233. It was a spacer material of 70.04.002.70 mm × 70 mm × 4.5 mm thickness. Insert A was placed at the rear of the hard shell of the armor for the elbow.

  The above results show that the material of the present invention improves about 30% when used as a simple insert, the insert only adds 30 g of armor weight.

  FIG. 24 shows the results of tests obtained from foam samples 1 to 3 made from the materials of the present invention when subjected to the standard test procedure EN1621 detailed above.

  Graph 4 is a control test performed on a molded elbow pad including an encapsulated dilatant compound according to my previous patent application. The results achieved are just a little lower than 10 Kn and are excellent results. (Typical motorcycle products such as Dainese elbow pads achieve 22.5Kn with best results and about 28-30Kn on average.) Best results show that the pads provide maximum protection It was obtained by applying an impact force directly above the elbow joint.

  Graph 1 is No. 1 by Dow Corning. No. 15455-030, their compound no. 3 shows the results obtained using an open cell cellulose foam (large cell size 0.5 mm-3 mm), which is a lightweight version of 3179 and impregnated with a lightweight dilatant compound containing duolite spheres.

  Note that foams that are not impregnated with dilatant compound achieve very high results, possibly 100 Kn. It should also be noted that Graph 1 has two useful peaks and that the configuration of the sheet material of the present invention can be varied to obtain them.

  Graph 2 shows the results for different cellulosic foams impregnated with the same lightweight dilatant compound. This had a small cell size of 1-1.5 mm and the peak force was 8.9 Kn. Note that the graph still has a characteristic double peak shape and that the second peak is much higher than the first peak. This is because the sample has begun to break and is in the worst case. A stronger foam carrier material (ie polyurethane foam) with a protective coating should eliminate this high second peak.

  Graph 3 shows the results obtained using a small cell size foam carrier impregnated with a lightweight derivative of Dow Corning 3179 Dilatant Compound incorporating duolite spheres. It can be seen that the cell size of this foam was less than 1 mm and achieved a peak force of 4.2 Kn. This graph again has a characteristic double peak, but the second peak is only slightly higher than the first due to the different combinations of dilatant compounds and small cell size.

  This method allows the energy absorber of the present invention to be modified for different applications by using different carrier materials and different dilatant compounds depending on the application. It is also possible to layer the material so that each layer can cope with a different speed / force energy regime.

  FIG. 25 illustrates various ways in which the energy absorbing sheet material can be used in sports situations. The figure shows a football player's boot 95, ankle 96, heel 97, and shin region 98.

  As shown, the shin 97 is covered with a protective shin pad 98 that includes a rigid shell 99 with an energy absorbing sheet backing 100 of the present invention.

  The heel region 97 and the lower part of the ankle 96 are protected by an energy absorbing armor 101 made from the energy absorbing material of the present invention as shown in FIG. The illustrated armor 101 has a number of bubbles 102 formed on its surface that are filled and / or associated with a dilatant material that absorbs kicking energy in the heel or ankle region.

  Another armor 103 made from the energy absorbing material of the present invention is placed over the wearer's foot in boot 95 to prevent metatarsal bone damage as a result of kicks or other pressure applied to the area. prevent.

  The illustrated boot 95 also includes a shock absorber 104 that can be made from, for example, the hexagonal material of the present invention shown in FIG.

  All the examples of the sheet material of the present invention described above are different from my original patent because the energy absorbing material is not included in the envelope.

  The elastic carrier can be coated with protective coatings such as Dow Corning® 84, Z6070 and Silof® 23A catalyst and 3481 substrate and 81T catalyst. Coatings such as these can be applied in any suitable manner. It is also possible to use a coating that actually reacts with the surface of the dilatant material. These not only provide a protective layer, but also crosslink with the surface of the dilatant material to further protect the surface. However, alternative methods of protecting the surface or forming a protective skin on it can be used. Merely by way of example, this can be accomplished by changing the material to form an extra crosslink or protective skin when exposed to the proper conditions. However, the protective coating can be similar to that of Raychem 44 spec wire, for example, a radiation crosslinked fluoropolymer bonded to a radiation crosslinked polyolefin.

  The protective coating helps protect the material of the present invention from potentially harmful chemicals such as those found in dry cleaning and the like.

  Suitable energy absorbers are strain rate sensitive materials, including dilatant compounds whose mechanical properties change upon impact as described above. In addition to such dilatant compounds, the energy absorbing material can also include a lubricant (eg, a plasticizer or diluent), a filler (eg, a thickener) or the like. Suitable dilatant materials include boron or polyborosiloxane containing an organosilicon polymer. Alternative polymers with dilatant include xanthan gum, guar gum, polyvinyl alcohol / sodium tetraborate as well as other hydrogen bonded polymer compounds. Examples of suitable dilatant materials are disclosed in WO 00/46303, the disclosure of which is hereby incorporated by reference.

  A suitable polyborosiloxane is a borosiloxane copolymer, which can be prepared by condensation of boric acid or boric acid ester with silanol-terminated polydi (alkyl and / or aryl) siloxanes.

The siloxane group of the preferred borosiloxane copolymer has the formula — (OSiR ₁ R ₂ ) —. Here, R ₁ and R ₂ can be the same or different and each independently can be a substituted or unsubstituted alkyl or aryl group. Preferred such alkyl groups contain 1 to 6 carbon atoms, more preferably 1, 2, 3, 4 or 5 carbon atoms. A preferred substituted alkyl group is a hydrofluoroalkyl group. In a preferred embodiment, one or both of R ₁ and R ₂ is a methyl, phenyl, or 1,1,1, trifluoropropyl group. Suitable siloxane groups include the following:-(OSiMePh)-,-(OSiMe ₂ )-,-(OSiPh ₂ )-, and-(OSi (CH ₂ CH ₂ CF ₃ ) Me)- Me is a methyl group and Ph is a phenyl group.

The borosiloxane copolymer used in the practice of the present invention can include two or more siloxane groups each having a different combination of substituents R ₁ and R ₂ , where the siloxane groups are of the formula — (OSiR ₁ R ₂ ) _n — Is preferably a block or unit. Here, n is an integer of 4 or more and 50 or less. Suitable such polysiloxane units are (OSiMePh) _n , (OSiMe ₂ ) _n , (OSiPh ₂ ) _n , (OSi (CH ₂ CH ₂ CF ₃ ) Me) _n , [(OSiMe ₂ ) _a (OSiMePh) _b ] _n and [(OSiMe ₂ ) _a (OSiPh ₂ ) _b ] _n , where n is as defined above, a and b are integers from 1 to 49, and a + b = n is there. In [(OSiMe ₂ ) _a (OSiMePh) _b ] _n and [(OSiMe ₂ ) _a (OSiPh ₂ ) _b ] _n , the two types of siloxane groups can be placed alternately or randomly in the polymer chain.

  Suitable borosiloxane copolymers for use in the present invention are those included in Dow Corning® 3179 Dilatant Compound and Dow Corning® Q2-3233 bouncing putty.

  Examples of suitable lubricants include silicone oils, fatty acids, fatty acid salts, and hydrocarbon greases. Suitable fillers include solid particulate and fibrous fillers such as silica, silica and / or polymeric microspheres, phenolic resins, thermoplastic materials, ceramic materials, metals, and pulp materials.

  Suitable dilatant materials for use in the practice of the present invention are Dow Corning® 3179 Dilatant Compound and Dow Corning® Q2-3233 bouncing putty.

The perspective view which shows one type of carrier material which forms a part of energy absorption sheet of this invention. Sectional drawing after adding a dilatant compound to the carrier material shown in FIG. 1 in order to form the energy absorption sheet of this invention. The fragmentary sectional perspective view which shows the alternative form of the energy absorption material of this invention. The figure which is the same as that of the material shown in FIG. 3, but the state in which the hole was formed there. FIG. 3 is a perspective view of another type of carrier material. Sectional drawing after adding a dilatant compound to the carrier material shown in FIG. 5 in order to form the energy absorption sheet of this invention. FIG. 7 is a perspective view of still another type of carrier material having hexagonal holes that forms part of the energy absorbing sheet of the present invention. Sectional view of another type of carrier with bubbles formed. FIG. 6 is a cross-sectional view of yet another carrier in the form of a quilted carrier material. Sectional drawing of the energy absorption module for the energy absorption materials of this invention. Sectional drawing of the energy absorber of one form which concerns on this invention using the several module shown in FIG. 10 arrange | positioned at random. FIG. 12 is a diagram of an alternative form of energy absorber similar to that shown in FIG. FIG. 6 is a cross-sectional view of an alternative form of energy absorber according to the present invention using different shaped modules. FIG. 3 shows one form of energy absorbing extrudate that can be used to form an alternative energy absorbing material of the present invention. The perspective view of the extrusion of an alternative form. The figure of the extrusion of another form. 17 illustrates a method by which the extrudates shown in FIGS. 14-16 can be incorporated into the energy absorber of the present invention. The figure which shows the alternative form of the energy absorber which concerns on this invention. The 1st method of manufacturing the energy absorber of the 1st form of the present invention is shown. 2 illustrates a method of manufacturing an alternative form of energy absorber according to the present invention. The perspective view of the body protector shape | molded from the sheet-like energy absorption material of this invention. Sectional drawing of the body protector shown in FIG. 1 is a schematic cross-sectional view showing a protective insert made from the material of the present invention that can be used in existing protective clothing. The figure which shows the result of the energy absorption test effective in the material of this invention. The figure which shows the various uses of the energy absorption sheet material of this invention in the situation of a football.

Claims (61)

  A flexible energy absorbing sheet material comprising an elastic carrier having pores or cavities, wherein the carrier is coated or impregnated with a dilatant material.   The sheet material according to claim 1, wherein the dilatant material is a dilatant compound.   The sheet material according to claim 1, wherein the carrier is a spacer material.   The sheet material according to claim 1, wherein the elastic carrier is a spacer fabric including an elastic core sandwiched between a pair of coating layers.   The sheet material according to claim 4, wherein the elastic core includes a yarn layer, and the covering layer has a plurality of openings.   The sheet material according to claim 5, wherein the opening of the covering layer has a hexagonal shape.   The sheet material according to claim 5, wherein the opening of the coating layer is a rhombus.   The sheet material according to claim 5, wherein the yarn is woven into an elastic pile.   The sheet material according to claim 5, wherein the yarn is braided into an elastic pile.   The sheet material according to claim 8 or 9, wherein the yarn has a diameter of 0.05 to 1 mm.   The sheet material according to any one of claims 5 to 10, wherein the yarn is a single fiber.   The sheet | seat material of Claim 4 in which many compressible bubbles are formed in the outer surface of each coating layer.   The sheet material according to claim 4, wherein an elongated hollow channel is formed in the compressible core.   The sheet material according to claim 13, wherein the channels are tubular and parallel to each other.   The sheet | seat material in any one of Claim 1 thru | or 14 by which the hole is formed in the said sheet | seat.   The sheet material according to claim 1, wherein the elastic carrier is formed of a foam material.   The sheet material according to claim 16, wherein the carrier is an open-cell foam.   The sheet material according to claim 1, wherein the elastic carrier is a fleece material.   The sheet material according to claim 1, wherein the elastic core is a “Scotch Bright” material (trademark).   A flexible energy absorbing sheet material comprising an elastic core of an individual module made from a dilatant compound sandwiched between a pair of coating layers.   21. The energy absorbing sheet according to claim 20, wherein the modules are randomly disposed within the compressible core.   21. The energy absorbing sheet according to claim 20, wherein the modules are arranged in rows with aligned axes over the entire width of the sheet.   21. A sheet material according to claim 20, wherein the module comprises parallel elongated hollow tubular members.   24. The sheet material according to claim 20, wherein each module has a coating layer thereon.   The sheet material according to claim 24, wherein the coating layer is a hard skin of the dilatant material.   The sheet material according to claim 20, wherein the module has a spherical shape.   The sheet material according to claim 20, wherein the sphere is hollow.   21. A sheet material according to claim 20, wherein the module is spherical and has a lightweight center.   An energy absorbing sheet material comprising yarn formed from a dilatant compound that is woven or braided into a compressible layer.   30. The energy absorbing sheet material of claim 29, wherein the compressible layer is housed between a pair of spaced apart sheets of support material.   30. A sheet material according to claim 29, wherein the yarn has a coating layer thereon.   32. The sheet material according to claim 31, wherein the coating layer is a hard skin of a dilatant material.   32. The sheet material according to claim 31, wherein the coating layer is a separated layer.   The sheet material according to any one of claims 29 to 33, wherein the yarn is hollow.   The sheet material according to claim 34, wherein the yarn has a fiber core.   36. The sheet material according to any one of claims 4 to 35, wherein one of the covering layers is a woven material containing a polycyclic aromatic amide yarn.   The sheet material according to claim 36, wherein the other coating layer is a woven fabric layer.   38. The sheet material according to claim 4, wherein the two covering layers are made of the same material.   The energy absorbing sheet according to any one of claims 1 to 38, wherein the dilatant compound is a dimethylsiloxane hydroterminated polymer.   40. The energy absorbing sheet according to any of claims 1 to 39, wherein the dilatant compound has a duolite sphere or a lightweight filler therein.   41. The energy absorbing sheet material according to claim 1, wherein the dilatant compound is Dow Corning 3179.   Heating the dilatant material to convert it from a normal semi-solid state to a flowable form; and incorporating the flowable material into the elastic carrier to impregnate the carrier with the dilatant material. A method for producing an energy absorbing sheet material comprising an elastic carrier having a dilatant material therein.   43. The method of claim 42, wherein the dilatant material is heated to 150C.   The dilatant material is fed between a pair of spaced sheets of material with pores or cavities therein and then between a pair of heated rollers, the heated rollers passing the dilatant material into the pores of the material of the spaced sheets. 44. A method as claimed in claim 42 or 43, wherein the energy absorbing sheet with indented and dilatant material is configured to emerge from the roller.   43. The method of claim 42, wherein the carrier is a foam and the flowable dilatant material is pressed into the foam under pressure at about 150 <0> C.   Using a solvent to reduce the viscosity of the dilatant material from its normal semi-solid state to a flowable foam, pouring the diluted dilatant material into a carrier, and finally forming the sheet-like energy absorber from And a step of removing the solvent. A method for producing an energy absorbing sheet material comprising an elastic carrier impregnated with a dilatant material.   47. The method of claim 46, wherein the solvent is evaporated from the sheet material by applying heat to the sheet material.   The method according to claim 47 or claim 6, wherein the solvent is propanol, isopropyl alcohol, methanol, dichloromethane, trichloromethane, or a mixture thereof.   49. The sheet material according to claim 1, further comprising a lubricant and / or a filler.   The material according to any one of claims 2 to 49, wherein the dilatant material is polyborosiloxane.   51. The material of claim 50, wherein the polyborosiloxane is a borosiloxane copolymer. The borosiloxane copolymer each comprises a plurality of siloxane groups of the formula (OSiR ₁ R ₂ ), wherein R ₁ and R ₂ can be the same or different, each independently a substituted or unsubstituted alkyl group or aryl 52. A material according to claim 51 which is a group.   53. The material of claim 52, wherein the alkyl group contains 1 to 6 carbon atoms. One or both of R ₁ and R ₂ is a methyl group, a phenyl group or a 1,1,1, material of claim 52 which is a trifluoropropyl group. Each of the siloxane groups has the formula _{(OSiMePh), (OSiMe 2)} , material of claim 52 having a (OSiPh _2), or _{(OSi (CH 2 CH 2 CF} 3) Me). Material according to any one of borosiloxane copolymer, 52 claims comprising two or more types of siloxane group, each with substituents R ₁ and R ₂ different combinations 55. Siloxane groups are those to the formula (OSiR ₁ R _{2) n} block or unit, where n is greater than or equal to 4, according to any one the preceding claims 52 a 50 less than or equal to an integer 56 material. The borosiloxane copolymer has the formula _{(OSiMePh) n, (OSiMe 2} ) n, (OSiPh 2) n, (OSi (CH 2 CH 2 CF 3) Me) n, [(OSiMe 2) a (OSiMePh) b] n or [(OSiMe ₂ ) _a (OSiPh ₂ ) _b ] _n containing _n polysiloxane units, where n is as defined in claim 10 and a and b are greater than or equal to 1 and an integer less than or equal to 49 58. The material of claim 57, wherein a + b = n.   59. A material according to any one of claims 49 to 58, wherein the lubricant is silicone oil, fatty acid, fatty acid salt, or hydrocarbon grease.   The material according to any one of claims 49 to 59, wherein the filler is a solid fine particle or a fibrous filler.   61. The material of claim 60, wherein the filler is silica, silica and / or polymeric microspheres, phenolic resin, thermoplastic material, ceramic material, metal, or pulp material.

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