DE1504261A1 - Porous solid body and method of shaping the same - Google Patents

Description

D e c h r e p o rt pores of solid bodies and methods of shaping The invention relates to the same; them on a porous solid body or the like and up; a method of molding the same.

Porise solid bodies according to the invention can be used particularly well as Use molds for vacuum forming cardboard or the like. Such shapes according to the invention reproduce the contours and the surface of a model and have the advantage that they can be used at low temperatures or at room temperature can be produced so that harmful effects such as distortion and shrinkage, which can be caused by the effect of heat during manufacture, are avoided0 The pores of the body according to the invention can additionally with a Binder, such as a resin or metal, are filled. The resulting Bodies have great strength and are therefore useful for use as gauges, templates, models, porms and the like in many manufacturing processes.

The porous bodies previously used for such purposes had a number of disadvantages. Among these, in particular, did mention that it was impossible was to faithfully reproduce the outlines and surface of an I-model, and because of the use of particles larger than the details of the see below reproducing Oberfoche.

Attempts have also been made to use finer particles. However, this resulted in bodies whose porosity meets the commercial requirements Pormen or the like was not enough. According to another known method were Metal particles sintered to form a porous body. requirement for the However, using this process is a template that can withstand the high sintering temperatures able to withstand. Such templates are very costly, additional @ I cause the high temperatures, such as those used for joining by sintering or for ceramic Binders are required, shrinkage and warpage of the porous mass. As a result, very expensive processes are required to reduce or reduce shrinkage To compensate for warping.

The main object of the invention is a method to create porous bodies that can be used as molds, and which are carried out at room temperature. can, ao that templates let us use those made of non-destructible materials such as Wood, Plastic, hard wax, paper or the like are made, The manufacture at room temperature also has the advantage that the porous bodies do not shrink or warp.

The invention also provides a method for forming porous Bodies that have great strength and rigidity.

The invention also relates to bodies and a method of manufacture same, in which the pores with another binding material, e.g. resin, metal etc., are filled to provide even greater strength and rigidity for use in the production of patterns, shapes, formworks, etc. to achieve. nas procedure according to the invention is to be seen essentially in that the surfaces of £ a distributed single solid particle evenly with a non-solid heat Curable to be coated in resin, which is dissolved in a volatile solvent is that the solvent is driven out of the de, rart coated particles, so that they were evenly covered with a thin liquid film of the heart are, however, spaces between the parts remain that the thickness of the coating is chosen so small that the spaces between the coated Particle are not filled in if they are brought into direct contact with one another, so that the coating is displaced at the points of contact that the coated Particle is pushed into a mass of predetermined configuration. before that Resin is cured to bring the Teilohen in direct contact with each other and pressing the resin coating from the contact points into the spaces without to fill this in, so that a porous substance is formed that this compact porous Substance left in the chosen configuration and then subjected to conditions will. which after a sufficient time lead to hardening of the Harilberzuges, ao that the parts are connected to each other.

The fine particles used to make the body can E.g. made of metal, quartz, glass, fireproof material. e.g. clay, or other solid, finely divided materials. Preferably, the particles should behave as one They are not of uniform size. The average particle size can between a micron or lower. if such particles are available until su 0.8 mm or more, depending on the purpose of use of the body.

The hardenable resin type used is preferably which undergoes initial hardening at around room temperature. The final hardening can be used at temperatures of 38 to 2050 C (10O to 4000 F) preferably are carried out in stages A wide variety of resins can be satisfactory use including epoxy resins made from biphenol and epichlorohydrin with suitable Hardeners such as diamines, dibasic acids and the like, also phanolormaldehyde resins, , Urea-formaldehyde resins, and polyesters modified with styrene or the like along with a catalyst such as benzoyl peroxide or other organic peroxides The liquid resin is listed in a volatile solvent, e.g. methylene chloride, Methyl ethyl ketone, etc. The resin solution is the thinner, the finer the particles are.

For particles with a diameter of about 0.5 mm (mass width 30 to 40) approximately equal parts by weight of resin and solvent are used during for particles 1 to 10 microns in diameter, four parts by weight of solvent to one part by weight of resin are preferable.

A preferred method of coating the particles, in particular smaller particles, consists in treating them and the resin solution with ultrasound, A typical process comprises the steps of the solid particles in a cloth bag or the like are filled that this bag in a Container nitt the Resin solution is brought and the container as well the contents by means of an ultrasonic generator for one to five minutes Ultrasonic high vibrations is treated0 Larger particles can ZtBo in which the Resin solution containing container are coated by turning.

After coating, the resin solution is allowed to drain and removed the solvent by evaporation, preferably at room temperature, until the particles are essentially touch-hackneyed. The coated particles are then placed in a porm or framed stencil with a suitable Adhesive is coated, and are then compacted by applying light pressure by hand. The shape and layer of the coated particles are then made into a flexible Brought airtight bag, which is connected to a vacuum line, around the To compress particles further, applying additional hand pressure if necessary The vacuum connection is then turned off and the airtight Bag carefully removed to avoid moving the particles.

The resin is still hardened at this point in the process is before the compaction of the particles as a thin liquid film Compressing the particles until they come into direct contact with one another becomes the liquid coating pushed away at the immediate contact points, but with the at the contact points adjacent spaces are bridged. The coating should be so thin that the Hars displaced does not fill the spaces between the particles. It can be seen that when using very fine particles, the resin film prior to compression and compression must be very thin in order to displace resin until the spaces between them are filled to avoid.

The process of compacting the particles is schematic in the drawings shown.

Figure 1 shows the sequence of process steps in the Method according to the invention; Figure 2 shows a number of coated ones Particles before compaction; Pigur 3 shows the particles after compaction; figure 4 iet a plan view of a Porm for the method according to the invention; figure 5 is a side view, partially in section, of the mold of FIG and FIG. 6 is an enlarged section of the shape neoh FIG. 5.

According to Figure 2, the particles 10 with a thin film 12 of a liquid resin coated. They are drawn spherically, although most of them Substances have practically no spherical shape. After compaction, the particles stand in direct contact with each other at points 14, with no more resin film located between the particles (see Figure 3). The film (coating) 12 is of the Touch points 14 pushed away and bi1d.t.Sriic.qn.; En. \. T.een points to the Holding particles together without the gaps. 16 to be completed. It turned out that the thickness of the coating 12 is less than 2.5% of the diameter of the particles 10 should be in order to avoid filling in the spaces 16 0 flat after removal the compacted particles and the model from the vacuum bag are left in the resin cure to an initial hardening state while the particles are in contact stand with the shape. If epoxy resins are used, hardening takes place in 8 to 16 8 hours at room temperature or in about four hours at 980 C.

After the preliminary hardening, the agglomerated particles become removed from the mold and the porous M8see finally hardened. preferably in stages. When using epoxy resins, the following card procedure has proven to be found satisfactory: one hour at 65 ° C (150 ° F), one hour at 800 C (1750 S), one hour at 940 0 (200 ° P) and two hours at 1200 0 (250 ° P). If the body has to withstand temperatures of more than 1200 C, another can One hour curing at 1800 C (3500 F) should be provided, the solid porous body is now ready for use.

If the body is to be used as a vacuum mold, is preferred a backing layer of larger particles than intended for the surface used. If accordingly the coated surface particles against When the form is compressed, it becomes a layer of coarser material, with a covering provided particles are placed on top of this and compacted and the entire mass later hardened.

The pores of the body produced in this way can be filled, e.g. by means of an additional binder, such as a thermosetting resin or like that. This is done in such a way that the resin is sucked into the pores are brought and then hardened.

For example, porous bodies made of aluminum, steel or copper powder are made, in addition with a thermosetting resin in that described above Wise filled and the ge @@@ r @te body then machined, drilled or be cut, for example by conventional methods, so that objects are produced leave that when editing as forms, stencils, gauges or the like are useful, EB can also be a metallic substance used to fill the pores For example, porous bodies made of finely divided steel or stainless Steel made according to the above processes into a chemical Nickel bath of that described in U.S. Patents 2,532,283, 2,658,841, and 2,658,842 Bring kind or in an atmosphere of gickelkarbonyl to the pores with nickel to be filled out. It therefore appears that the porous body contains many areas that are not coated with a resin layer, or that the resin contains holes which can be plated through the metal.

Porous metal body according to the invention made of finely divided metals have high thermal conductivity and electrical conductivity, which are up to the values of solid metals is approaching. Let objects made from such bodies very useful for pormen, stencils etc. where it is used the thermal conductivity is important, for example in the case of vacuum forming with thermal hardening Injection molds and the like 4 One made according to the invention Shape can be any shape and size. Such a porm is shown in Figures 4 to 6. The body of the form is made of a large one Number of particles composed, which are connected to each other to form a mass, which is porous through and through, one side of the mold serves as the molding surface on which the object to be molded is applied. The opposite side of the Form is connected to a tight container that is connected to a vacuum line is, so that a suction can be exerted on this side, which is through the whole shape continues to the mold surface and in this way cardboard pulp, Pulls plastic or the like against the mold surface. in the drawing is the Wet of the form, which is composed of small particles, generally with the Number 20 denotes and the version of the wet, which extends over the rear face extends, denoted by 22. Is on this serving as a tight container version a vacuum line 24 connected0 The socket can be made of any Be made of material, e.g. metal or fiberglass, to which a suitable Plastic binder is added. The vacuum line leads to a suitable one Vacuum source o The outline of the mold surface can be permanently shaped and the surface can be designed to have a desired Surface texture has, e.g. grainy or the like.

The small particles that make up the bulk of the mold can be made of any material, e.g. from volcanic ash, from sand, gravel, glass, granulated metal such as aluminum, bronze or steel, crushed Walnut shells, plastic objects, small balls or the like o As very Small particles can be used with emery grains, such as those used for sandpaper manufacture are common.

The porm can be made up of particles through and through of the same size, or of a series of layers made up of particles of different sizes. To achieve a suitable porosity, should be used to produce the layers or the entire form - if these are made made of the same particles -a substantially uniform size0 If a mixture of particles of different sizes is used, the Tendency that the small particles fill the spaces between the larger particles fill in and in this way form a dense structure that is not the desired Porosity of the porous body results if the amount of fine particles is not careful is measured.

Although the entire mold can be made from the same particles, it is preferably made up of a number of layers with different Particle size made0 The forming surface layer should preferably contain fine particles that allow an accurate reproduction of the surface texture and ensures that the suction applied to the back of the mold through a multitude of very fine openings in the surface acts as a result, that the material sucked against the mold surface over the entire surface of this is applied, and the fineness of the porosity prevents on the other hand that the to be molded material is sucked into the mold, which can then be applied ru layer consist of larger particles. The two spaces between the particles in this The layer would then be larger than the penetrations between the particles in the the layer forming the surface of the mold, but they are connected to them. the The entire shape can be produced from a desired number of pieces. Both Shapes -according to Figures 5 and 6, three different layers are used, and although in FIG. 6 the layer "6" forming the mold surface, the second layer 28 and the innermost layer 30. the particles shown in Figure 6 are exaggerated shown large. The main purpose of using multiple layers is in that the manufacturing cost is reduced and a favorable porosity is achieved is so that a high suction is exerted on the mold surface and the suction is distributed substantially uniformly over the entire mold surface.

The particles used to make the molding surface can be Less than 19 microns (0.005 ") in diameter, e.g., 8 microns or 3 microns However, micron (0.003 "or 0.001") particles can often be used. As said, it is desirable that the particles are generally of the same size point and have a shape that ensures a large number of air flow paths. If particles i-n or the forming surface layer are used with a Diameter of 0.06 mm (0.025 ") allows the particles in the next layer have a diameter smaller than 0.3 mm and the diameter of the particles in the coarse layer can be less than 6 mm or up to 25 mm.

The following are some examples of the practice of the invention given. The parts are to be understood as parts by weight.

Example 1 The. made the following solution: parts epoxy resin (2,2 bis (4-hydroxyphenyl) propanepichlorophydri condensation product 100 hardener (1,8-diamino-p-menthane 22 methylene chloride 400 The above solution was placed in a container and 2000 parts by weight of finely divided steel particles with an average diameter of 10 microns wrapped in a cloth bag and placed in the solution brought, the container was then equipped with a commercially available ultrasonic generator of 80 watts and 40 kHz (for a one gallon capacity) three minutes long treated. The bag was then removed and drained off the excess Solution, the bag was opened and the particles scattered on absorbent paper, to allow the solvent to evaporate 30 minutes were touch-sensitive, they were placed on the surface of a frame Plaster of paris model brought with liquid wax and a thin polyvinyl alcohol film nls was non-stick coated. The particles were then removed from the frame compressed to fill this up. The entire arrangement was now in a plastic bag @ brought, which was provided with a suction connection to which a vacuum source is connected The pressure by hand was maintained until the wet was solid. The vacuum was then switched off, the filled model surrounded by a frame from the plastic container removed and cured for twelve hours at 250 C (750 F). after @ieser preliminary hardening was the proous body sor. d @ m M @ dell removed and the following Submit final hardening One hour at 650 C (150 ° F), one hour at 800 C (175 ° F) and two hours at 1200 C (2500 F), it was made in this manner porous bodies modeled the model and its texture exactly and gave an excellent one Vacuum shape.

Example 2 The procedure described in Example 1 was used to prepare steep a porous cylinder 4 cm (1.5 ") in diameter and 8 cm (3") long The porous cylinder was used by immersion for three minutes in the following bath. sensitized: 400 com hydroquinone 100 cc pyrocatechol 1000 cc Acetone.

The cylinder was then activated for two minutes in the following bath: 10 g tin chloride 40 cc hydrochloric acid 1000 cc distilled water.

The po @se cylinder was then immersed in a chemisohesic nickel plating bath brought with the following composition: nickel sulfate 0.08 mol per liter of phosphoric acid Sodium 0.23 mol per liter of acid 0.3 mol per liter of propionic acid 0.003 mol per liter, After t6 hours the pores were completely covered with metallic Nickel filled and the outer surface was plated with nickel. The one made in this way Body was easily drilled, cut, and machined.

Example 5 The procedure of Example 1 was followed on the preparation of a porous cylinder. which was placed in a pipe by the nickel carbonyl passed for 168 hours. The finished body was complete with Nickel filled.

Example 4 The method of Example 1 was used to manufacture a porous 3norm made of glass particles with an average diameter of about 50 microns applied. The finished shape had excellent porosity and reproduced true to the Modoll The form was then sensitized and activated according to the example 2 and chemically nickel plated for 20 minutes at 90 ° C: 1900 F) in the following Bath 7 oz. Of Nickel Chloride, 1.5 oz., 40 g. Sodium Phosphate, 40 g. Sodium Citrate (1.5 oz.) 4.5 liters of water (lagl.).

The glass mold was plated with nickel in this way, without the To fill pores.

The porous body according to the invention can in this way with metallic, zOBo nickel, 'copper and silver are plated, and it can be seen through that Plating the pores can either be completely or partially filled, of course Both riveted and non-metallic porous bodies can be used in the above Type chemical plating.

Example 5 It got there. Procedure according to Example 1 applied, and although using 1000 parts by weight of a fine aluminum powder with a particle diameter of 25 microns, the finished shape was designed for Suitable for vacuum forming. A vacuum was used to show the filling of the pores applied to the back of the mold and 100 parts of a har @@@, the 22 parts hardener were added according to Example 1, n sucked the form. After curing at room temperature @ overnight the final hardening at increased temperature according to the example! carried out. The finished body was very strong and easy to machine bearbei @@@@ drill and cut.

As stated above, it is preferable when making vacuum molds according to the invention to use a backing layer, the coated particles thereof have a larger diameter. Such particles can be, for example, 3 mm in diameter exhibit. The surface layer must consist of much smaller particles, to faithfully reproduce the outline and texture of the original. The thickness of the surface layer can be relatively small, about 3 to 6 mm in size.

The strength and dimensional stability of the body according to the invention stems from the fact that all particles are in direct contact with one another, without a binder film in between. The body is therefore as compact as possible without changing the shape of the individual particles a very thin liquid and therefore displaceable harefilm enables the direct Contact of the particles with each other and a connection of the same chen filling of the spaces.

The invention can be thought within the scope of the general invention still modified or carried out in another way.

Claims (18)

Claims 12 A method for forming porous solid bodies, thereby it does not appear that the surfaces of purely distributed individuals solid particles evenly coated with a non-solid thermosetting resin which is dissolved in a volatile solvent that the solvent is expelled from the particles coated in this way, so that they are uniformly with are coated with a thin liquid film of the resin, but with gaps remain between the particles that the thickness of the coating is chosen so small is that the gaps between the coated particles are not filled out when these are brought into direct contact with each other, so that the Coating at the points of contact, is displaced that the coated particles in a wet of a predetermined configuration is pressed before the resin cures is to bring the particles into direct contact with each other and the resin coating from the points of contact: n to press the gaps without filling them @ us, so that a porous substance eats formed, and that the compact porous substance in the g selected configuration g (a @@ en and then subjected to conditions according to e @@ e allow sufficient time for the resin coating to harden. so that the particles interrelate are connected. 2. The method according to claim 1, characterized in that when coating of the particles with a coating of thermosetting resin ultrasound au9 the in the volatile solvent and the resin particles dissolved therein becomes0 3. The method according to claim 1 or 2, characterized in that the resin a biphenolipichlorohydrin condensation product and an associated hardener are used will, 4. The method according to claim 3, characterized in that the resin in one Meythylenechlorid-containing solvent is dissolved 5. The method according to claim 1 or 2, characterized in that a resin is used, which is at room temperature and that the hardening is carried out in such a way that the compacted porous mass in the final configuration at room temperature during a for pre-hardening @@@@ calibrating time is left so that the particles d mass cement together, and that the mass is then subjected to the final hardening through which the resin finally becomes is hardened 6. Method according to Anopruch 1 to 5, for the production of proous bodies with great strength and high thermal conductivity, characterized in that to manufacture same particle made of a solid, thermally conductive Metal can be used. 7. The method according to claim 1 to 6, characterized in that im Following the production of the porous body, the pores of the same with a liquid Bindemittei are filled in, which can be found without displacing the. individual particles let harden, and that one then. the hardening is carried out. 8. The method according to claim 7, characterized in that as a binder a thermosetting resin is used0 9. The method according to claim 7, characterized in that that a porous body made of metal particles with a to a metal decomposable metal compound treated so that the pores of the porous body be filled with a metal as a binder and a solid body results. 10. The method according to claim 9, characterized in that for production iron particles are used of the porous body and the finished porous body placed in an aqueous nickel plating bath so that the pores are covered with nickel fill out 11. The method according to claim 9, characterized in that the porous body is made of iron parts and the finished one porous body in an atmosphere of nickel carbonyl is placed around the pores to be filled in with nickel. 12, method according to claim 1 to 11, characterized in that the porous mass is compacted after introduction into the final shape before the resin is hardened to such an extent that the resin coating is displaced between the contact points of the particles is no longer possible. 13. The method according to claim 1 to 12, characterized in that Particles with a particle size of one micron to 0.8 mm can be used. 14. The method according to Ans @ ruch 1 to 13, characterized in that the correct thickness of the coating on the particles by the Xrswd of the dilution of the resin or the like is set in the solvent. 15 Porous body, characterized by a compacted mass of finely divided individual particles that are in direct contact with one another and leave gaps between me, whereby the individual particles pass through cured resin coating bonded together at the points of contact of the particles are. 16. Foröser body according to claim 15, characterized in that the resin from a biphenolep @ chlorohydrin- Condensation product and a suitable hardener. 170 Porous body according to claim 15 or 16, characterized in that that as particles metal particles with an average diameter between one micron and 0.6 mm are used0 18. Body according to claim 15 to 17, characterized characterized in that the pores are filled with an additional binder, which is associated with the coating of the particles, 190 body according to claim 18, characterized in that iron particles are used as the particles and as additional Binder nickel 20 Porous body according to Claims 15 to 17, in particular for use as a vacuum mold; characterized in that the body consists of a number of layers is built up that the serving as a molding surface layer of particles of sufficient no size manufactured icit to faithfully reproduce the surface texture of the template. and that the subsequent layers each consist of particles with larger diameters are made. 21. Porous body according to claim 20, characterized in that this with the exception of the shape of the surface, it is surrounded by an airtight container Has vacuum connection. 22. Porous body according to claim 20 or 21, characterized in that that the particles used to produce the layer forming the mold surface have a diameter smaller than 0.08 mm, Read more e