FI64762C - FOERFARANDE FOER FRAMSTAELLNING I EN FORM AV EN MAONGFORMAD PRDUKT AV EN BLANDNING BESTAOENDE AV PLAST OCH EN RELATIVT OST ANDEL FYLLMEDEL - Google Patents

Description

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C (45) Γ.-ter.lli ry ^ 'ty ^ ^ 1 * 34 (5i) K ».ik3 / tat.a3 B 28 B 1/10, B 29 C 3/00 ENGLISH - FI N LAN D (21) kup * · ι »« Μι · ΐΜΐ · ιυ · - P »t« it »n» «(nli * g 753529 (22) Htktmltpilvt - Am & kninpda (15.12.75 ^ ®) '(23) AlkupUvi — Glltightudig 15.12.75 (41) Become Public - Bllvlt offentllg, Qfj. Γ (j

Patents and registrars (44) NihtMUpuo * jt kuLJuiksUun pvm.-, n nq o.

Patents and registrations Tenst utnagd och uil.ikriftM pubUcerid J -5 (32) (33) (31) Pjrydetty etuoikeus —Begird prlorltst l6.12.fb

Sweden-Sweden (SE) 7 ^ 15768-6 Proven-Styrkt (71) Svensk Härdbetongteknik. AB, Styrbordsgatan 7, S-U21 76 Västra Frölunda,

Sweden i-Sverige (SE) (72) Georg Björhaag, Ämäl, Sweden-Sverige (SE) (7 * 0 Leitzinger Oy (5 * 0 Method for making various products in a mold from a mixture of plastic and a relatively large proportion of filler - Förfarande för framställning i en form av en m & ngformad product av en blandning bestäende av plast och en en relativt stor andel fyllmedel

The invention relates to a method for producing multifaceted products in a mold from a mixture of plastic and a relatively large portion of filler, in which the lower mold is filled to a predetermined level with the mixture, and the upper mold is pressed against the filled mixture with a press head. vibrating the upper and lower molds, comprising the steps of: (a) lowering the upper mold (21) toward the free mass surface of the filled mixture during the first compression cycle which is vibrated to distribute the mixture in the mold and compress the mixture and remove air occlusions; a significantly higher compression pressure for the final compression of the mixture, with vibration forces applied to both the upper mold and the lower mold (16) during both compression cycles, already tka is oriented transversely to said compression direction, the vibration forces directed transversely to the compression direction have two transverse directions and the vibration forces of the lower mold are directed opposite to the vibration forces of the upper mold.

The object of the invention is to solve the problems which occur when compressing dry or slow-flowing, for example powdery, masses. An example of such masses is the so-called wood plastic, i.e. a plastic material which consists largely of a filler material, such as wood chips, asbestos, stone material, cellulosic material, which is cured together with the plastic component during the thermal process. Other such materials include, for example, concrete and other slow-flowing materials. Materials such as thermoplastics and aerated concrete cannot be filled into the mold by spraying, but must be placed in an open mold and pressed together within it. Due to the slow flowability of the material, it thus becomes difficult to fill especially complex molds with different cuts and cavities. Practical attempts show, for example, that exclusive filling of an open mold and compression with a press or top mold results in pieces with significantly different material densities and that if the mold is not the simplest but has different recesses, cuts and complexities, large "rat cavities" are created in certain mass areas. This can be aided to some extent by profiling the free surface of the filled material according to the bottom of the mold or the like (see e.g. British Patent 629,026). However, this provides only a partial improvement in the result and requires complex equipment and / or manual work.

Quilting of the filled mass has gained wider use. The mass is then "drained" by vibrating it. This vibration causes the mass to move so that it spreads in the mold, fills its various parts, in addition to which the mass itself pre-compacts in a certain way, giving a better result, i.e. a higher density of the finished piece of material when the final compression takes place. However, the vibration methods used have not yielded a completely satisfactory result, especially when using complex molds.

The above-mentioned vibration is described, for example, in Finnish patent application 53/72. In this known device, vibration is applied to the lower and upper mold so as to produce transverse impacts with respect to the compression direction. The impacts on the lower mold are mainly directed in the opposite direction to the impacts of the intermediate mold. Similar vibrating devices are also described in U.S. Patent 3,917,781 and British Patent Specification No. 14 14,056. The above application and publication describe general vibrating methods used to fill the simplest molds with concrete.

However, practice has shown that vibration alone is not sufficient to fill the most complex molds, especially when the casting mass is relatively thick and slow-flowing.

It is an object of the present invention to solve the above-mentioned problems. The method according to the invention is characterized in that the vibration effect on the upper mold takes place at a frequency different from the impact force on the lower mold. These frequency differences provide a very effective compression effect because the mass particles have different, different vibration numbers.

In the following, the invention will be explained in more detail with reference to the accompanying drawings, in which:

Figure 1 shows a side view of a press specially applied to the method according to the invention.

Figures 2 and 3 show cross-sections of the same press along line II-II and along line III-III, respectively, according to Figure 1.

Figures 4 and 5 are a longitudinal section and a main view, respectively, of a vibrator belonging to the press shown in Figures 1-3.

Figure 6 shows a partial section of a mold containing a press roll.

Figure 7 shows graphically the use of oscillations of different frequencies.

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Figure 8 is a sectional perspective view of a pallet with a mold for display.

Figures 9 and 10 are cross-sectional views of another embodiment of a loading platform, the section made in Figure 9 taken along line IX-IX in Figure 10 and the section shown in Figure 10 taken along line X-X in Figure 9.

Figures 11 and 12 show the roof panel in both side and sectional patterns, while Figure 13 shows a cross-section of the sole of the shoe placed in a mold where it can be made of plastic mass.

The basic idea of the invention is mainly to cause the upper and lower mold to vibrate with an impact effect which is mainly oriented transversely to the compression direction. In further development of this principle, vibrations are produced by varying the impact frequency, resulting in a resultant vibration variation that has a very beneficial effect on the adaptability of the compact to fill and compact the mold.

The press shown in Figures 1-3 forms part of an apparatus for making products made from slow-flowing press pulps. As shown in Figure 1, the press consists essentially of a body with a support part 22, a work table 23 and four columns 24 directly connected to the support part 22, but not to the table 23, with an upper part 25. The upper part comprises a powerful hydraulic device 26 with a piston supporting the press head 27. A work table 23, such as columns 24, is connected to the support part 22 and to the piston of the hydraulic device by elastic pads. Vibrators 28 and 29 are provided in the table 23 and in the press head 27. As will be shown below, the table 23 is intended to support a lower mold 16, into the opening 20 of which the upper mold 21 or the press head fits. The upper mold 21 is intended to act together with the press head 27 when this is lowered by the hydraulic device 26.

The press head with the tuft 29 is seen from above in Fig. 2 as seen on the section line II-II in Fig. 1, while the work table 23 is shown in Fig. 5 on the section line La III-III in Fig. 1. The position of the vibrators 28 below the table 23 is shown in Figure 3 as in the lower mold 16, which 64762 lacks the upper mold 21 shown here and which lower mold is located on the table 23. As shown in Figures 2 and 3, both the table 23 and the press head 27 are provided with four vibrators 28. and 29, wherein the mutually parallel axes are transverse to the axes of the other two remaining vibrators in each portion.

The longitudinal section of one vibrator is shown in Figure 4, according to which the vibrator has a housing 30 with mounting plates 31. The housing 30 includes an electric motor whose shaft 32 is provided with eccentric weights at both ends lined with lids 34. Two weights 33 are provided at each end of the shaft 32. , which can be turned relative to each other, in which case it is considered that the weights are placed in the same way at both ends of the shaft 32.

It can be seen from Figure 5 that the vibrator and its body on which the vibrator is built are subjected to a rotational force which is varied by unbalanced weights 33. The imbalance of the weight pair at each end of the shaft 32 and of course also the force obtained are adjustable by twisting the weights in each pair. The maximum possible imbalance is obtained with the position shown in Figures 4 and 5, in which case the weights are the same. If the weights of each pair are twisted against each other, the imbalance is neutralized.

The forces due to the rotating weights are directed as shown in Figure 5, i.e. to the right in quadrants I and II, to the left in quadrants III and IV, up in quadrant IV and down in quadrants II and III. If the vibrator is mounted on a workbench with a lower mold containing the appropriate extrudate, the upward force in squares IV and I causes the mass to pack and the downward forces in quadrants II and III to cause the mass to rise. According to the stiffness of the compact, it packs more tightly as the weight passes quadrants I and II. In this quadrant, these forces tend to move the mold to the right and due to the stiffness of the compact, it is compressed on the inner surfaces of the mold, which are oriented to the right, i.e. the compact will compress on the left walls of the mold.

In this way, it is possible to orient the compression of the compacted pulp in a desired manner by determining the directions of the vibrations required by the pulp. According to the arrows shown in Fig. 3, in the embodiment shown on the desk 23, the vibrators 28 are arranged so that the 6,676,72 plastic mass is packed along the right and upwardly directed walls in the mold 16. The arrangement of the vibrators 29 at the press head 27 is chosen so that Furthermore, the upper mold provides a packing effect against the inner walls of the lower mold, which power is directed to the left and downwards.

Of course, with the described method, it is possible to achieve compression of the compacted mass along the walls of the mold, regardless of the direction of the walls. This effect is very important in a compression process, for example when pressing an upper mold or press head down into a press-filled lower mold, where the pressure in the compression is mainly the desired firmness and uniform surface finish in the parts of the workpiece close to those surfaces formed by said mold walls. However, with the described vibration method, it is possible to achieve a substantially uniform firmness and surface finish on objects - even those of very complex shape - by using a press mass which is largely mixed with a filler.

However, it has proven possible to achieve an even better result improvement, which is achieved by using different stroke frequencies in different vibrators. According to the proposals based on practical experiments, the impact frequency of the upper mold vibrators according to Figure 2 is as follows:

Positions A and C = 8900 strokes / min.

Positions B and D = 6000 strokes / min.

These different, relatively high-frequency shocks are suitable for the upper mold, while the lower mold is used (see Figure 3):

Positions A and C = 2900 strokes / min.

Positions B and D = 2600 strokes / min.

However, the situation can also be the opposite, with a lower frequency being applied to the upper mold and a higher frequency to the lower mold. This is 64762 proved to depend on what mass is used. Thus, with concrete, high frequency has proven to be suitable for use in the lower mold, while with wood plastic, high frequency is used in the upper mold. In general, the impact conditions must be investigated by practical experiments and depend on both the mass and the design of the mold according to the particular need.

In order to achieve a suitable orientation, the vibrators must thus be variable according to their direction and frequency. Vibrators operating at the same desired speed do not always have to be synchronized mechanically or electrically, as they have been shown to synchronize with each other due to the impact they exert on the substrate. The vibrators are shown to be located along the center lines of the mold, but may also be located in the corners (see markings with 281 and 291, respectively).

How the variation of frequencies affects the impact effect (amplitude) is shown in Figure 7, which shows two combined sine curves with different frequencies. The combination, as can be seen, leads to an intermittent intensification in the moments when the shocks act together. It is this change in impact force that has been shown to provide excellent mobility and compaction of the mass. In practice, the highest substantial difference is obtained by the method described. Thus, bodies of very different material thicknesses have been practically of the same density in different parts, while bodies made by conventional methods, to which this particular vibration technique has not been applied, have shown very significant differences in tightness and also have large "rat cavities".

As an example of using the method, the following description can be given: 1. Filling the lower mold to the intended height with mass. This is most preferably done during vibration, saving time. Alternatively, vibration may occur after filling and it may often be useful to continue it after filling. Practical experiments have shown that when the free upper surface is present, the vibrator (i.e. the upper mold is not lowered) causes the free surface to tilt in the mold, see line A in Fig. 1.

θ 64762 2. Now lower the upper mold onto the free surface of the pulp while using its vibrators with a relatively slow movement lasting, for example, tens of seconds. It has been shown that the redistribution of the mass takes place into a flat surface, cf. solid lines in Figure 6. While the upper mold rests on the mass, the final spreading into the mold and vigorous compaction and the disappearance of all air colonies occur under vibration.

3. The final compression pressure of the order of hundreds of tons is now calculated, whereupon the final compression of the packed mass takes place.

4. The mold with its inner press head or upper mold can now be taken from the press and further cured. In the case of a plastic material, this is done in heat and in different ways for the various materials in general.

Figure 6 shows a part of the mold 16. As can be seen, the mold has a plurality of high density alloys, with a dense alloy 35 in the mold near the vertical wall and a less dense alloy 36 spreading in the middle of the mold. A plate 37 with suitable openings 38 is provided to distribute the alloy 35. After the alloy 35 is applied along the mold walls from the opening 38, the plate is removed, and the mixture 36 is poured into the mold from the uncovered opening 20. When the mixture is packaged as described by vibration, the denser mixture 35 is more tightly packed. With this method, it is possible to increase the strength of the corner parts in the articles to be produced so that they pack together enough even if the walls of the mold extend in the compression direction and also if there are special cuts.

Figure 8 shows a model of a loading platform, which is shown from above and turned upside down into a mold. The loading area, which is made in one piece, consists of three support beams 98 and parts 33 extending at right angles to them, forming an upper surface with four openings 100. The mold has a base 101 and four lockable sides 102 attached thereto. , of which only two are shown and which extend from the base 101. The parts 99 are formed by six printing pieces 104 (only two are shown) interconnected by rods 105. Three printing pieces 6 4 7 6 2 106 are provided for pressing the beams 98, of which only one is presented. The press pieces 106 are interconnected by a bellows 107 arranged to press the press pieces 104 when the press head or top mold formed by the press pieces 106 and the beams 107 is pressed down by the press head.

Figures 9 and 10 show a mold for a different type of loading platform. The loading platform 115 is formed similarly to the loading platform 97 shown in Fig. 8 by three beams 116 interconnected by a base portion 117. However, the beams 116 are hollow in contrast to the loading platform shown in Fig. 8. Three conical cavities 118 are provided in each of the outer beams and three larger cavities 119 are arranged in the center beam. Openings 120 extend between said cavities through the beams. The apertures 118 and 119 are formed from respective portions 121 and 122 of the press head 124 portion 123. Surfaces upwardly surrounding said apertures 118 and 119 in the mold pressing position are formed from surfaces 131 in said press head portion 123. The apertures 120 are formed by sliders or retractable cores. 126 movably arranged on the bottom wall 127 of the mold as seen in the upper position on the left in Fig. 9, more or less in the lower position on the right in Fig. 9. The transfer movement in the wall 127 in the slider 126 is provided with a sealing element so that the press is not squeezed out when the slider 126 is moved. . This can be pulled out of the mold by an annular holder 129.

The surfaces of the beams located between the surfaces surrounding the holes 118 and 119 are formed by the surfaces 130 in the portions 131 of the press head 124. These portions 131 are located in the outlets 132 in the portion 123 and are thereby moved during the pressing operation.

The main portion of the base portion 117 between the beams 116 is formed by a slider 126 when it is moved to its lowest position. The slider 126 is moved by parts 133 marked at the press head 124. These parts 133 are provided with outlets 134 in which the slider 126 is located when the parts 133 are moved by the part 123 when lowering the press head 124. The portion 133 further includes surfaces 135 for forming the remainder of the base portion 117 between the beams 116.

10 64762

The surface of the base plate 117 facing downwards in the pressing position forms the lower part of the mold via the base plate 136. This plate is movable by ejector rods 137 to remove the finished substrate from the mold.

When filling the mold according to Figures 9 and 10, the parts of the press head are placed with the sliders 126 in suitable planes so that the depth of the mixture is adapted to the finished product, varying in thickness. When pressed, the part 123 lowers at the press head 124 and thus brings with it the parts 131 and 133. At the same time, the part 133 compresses the sliders 126 downwards to the position shown on the right in Figures 9 and 10. The mixture is then pressed between different parts of the press head 124 and the base plate 136 in the lower part 128 of the mold and between the lower surfaces of the sliders 126 and said base plate, respectively. The finished product can then be removed from the base plate 136 by ejector titanium 137.

An example of products suitable for production by the method according to the invention is the roof covering in Figure 11. The roof covering is intended to be attached directly to the roof rafters, and the covering elements are arranged to join the sealing folds 108. The covering elements are provided with strips 109 for roof covering brackets. To allow water to drain downwards under the roof covering, the moldings are provided with recesses 110.

Figure 13 shows a mold 111 provided with a pusher 112. The mold, which is most preferably a multi-mold, is intended for making wooden shoe soles 113 from a press pulp. As shown, the cavity of the shoe sole 113 is positioned at an oblique angle to the mating surface 114. According to the method of the invention, by vibrating, it is possible to control the flow of the compact and the packing power towards the heel of the shoe sole 113, which provides an increase in the strength of the heel. Namely, it is not possible to obtain sufficient strength in the heel by pressing the presser 112. Namely, in a simple pressing operation, the force in the respective pressing mass depends on the thickness in the pressing direction. However, with the present method, it is possible to obtain a pre-compaction of the compression mass and its packaging between the mold and the presser, whereby it is possible to achieve the desired strength in all parts of the article.

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As shown in the appendix to Figure 6, the mold can be filled with mixtures of different configurations and different properties in terms of the strength, tightness, etc. desired. The various blends, as described above, are suitably distributed throughout the mold shapes and impart the desired properties to the article produced. In order to achieve this selected distribution, the filling must be carried out in several stages using plates (37 in Figure 6} which complement the plate 17 and are provided with openings (38 in Figure 6) arranged to pass through the compacted mass. exposed with suitable vibrator arrangements, as described in the explanatory texts of Figures 2 to 5. The compact may be pre-compacted, in which case in certain cases the compression may be directed to certain mold parts and / or certain parts of the press with a higher density than other parts as described above.

The above arrangements may be useful to perform under special conditions, such as in the case of very complexly shaped products and with particular attention to strength. However, it is generally not necessary to use such a special arrangement when using the vibrating method of the present invention, which can be used to mold articles of very complex shape.

Then, when the mold cavities have been filled, for example in a special filling station, the mold is placed on the table 23 in the press, whereby the presser 21 is pressed downwards by the press head 27. During the pressing process, the mold 16 and the presser 21 are subjected to vibration caused by the vibrators 28 and 29 via the table 23 and the press head 27. These vibrations are directed, as described above, in a manner that gives the finished articles to be produced the highest quality, i.e., the vibrations are directed depending on the design of the mold.

When the mold of Figures 9 and 10 is used, the slider 126 is pulled out during the filling operation. Prior to compression, the slider 126 is pushed in and into the pulp in the upper position, which is facilitated by the sharp end of the slider. This is followed by a pressing moment so that the press head 124 is moved downwards, whereby the slider 126 follows the downward movement and acquires its intended final lower position when the mass under the slider has reached its desired thickness. Thus, the mass condenses into the cavities of the mold in an unbroken layer on the side of the slider, guided by the head, but under it, guided by itself, whereby, as it moves down, it compacts the mass below.

At the end of the pressing moment, when the mold has taken on the shape determined by the mold cavities, the mold is suitably removed from the press to the designated heating station so that the mold would harden in the case of a curable plastic. Once the mold has cooled, it can be opened. This is done by raising the upper presser 21 and, if the mold is provided with sliders for lower sections, after removing them. The final ejection on the casting is preferably carried out by means of an emptying device, such as push rods or a removable mold base, or by pouring the sides of the mold upside down (cf. Fig. 7) and then lifting the molded part up.

In making the loading frame 97, as shown in Fig. 10, the side walls 102 of the mold are raised and locked together. The bottom of the mold cavity forms a plane from which the four bodies 103 rise. The mold is now connected to the plate 17 and the compact is filled here into a layer suitable for forming the parts 99. Six press pieces 104 are then introduced into the mold and a new layer of extrudate suitable for forming the beams 98 is filled into the mold in the areas behind the bodies 103 and the press pieces 104. For the pressing operation, the pressers 106 and 107 are introduced into the mold.

By pressing these down, it appears that the parts 107 press the printing pieces 104 down. By adjusting the weight vlys tracks 106 and lower side portions 107 of the underside of the weight 104 by a height, it is possible to obtain a suitable press 97 in different parts of the loading platform.

When manufacturing a roofing element according to Figures 11 and 12, it is important to achieve good strength in the moldings 109, which is difficult due to their large thickness, which depends on the strength of the remaining parts of the element in question. However, with the vibration method according to the present invention, it is possible to provide a lateral force with respect to the compression direction from left to right in Fig. 11, i.e., in a direction parallel to the main dimension of the cover. Thus, it is not possible to achieve a higher pressure in the strips 109 than can be achieved with a simple compression pressure. Tärytiimien induced into the mold right direction 13 64762 acting force is given on the right arrow in Figure 11, wherein the ram of acting as a driving direction is reversed. See Figure 11 the left-arrow direction.

The use of the described method in the manufacture of shoe soles is described above in the explanatory note of the mold shown in Fig. 10.

When water-soluble binders are used, for example a urea patch, it is advantageous to provide spring hooks (not shown) to hold the upper mold in place under spring pressure during the curing of the plastic material.

This allows the water vapor generated during curing to escape through the upper mold, which then rises slightly upwards. Conventional methods have shown that it is necessary to relieve the pressure once or twice during the curing process in order to release water vapor, which has caused relatively rough areas on the surfaces of the product which have thus had to be post-cleaned.

The result that underlies the invention is largely the result of long-term and intensive experimental work, but is, of course, based on certain theories and the monitoring of the results. The theory for the distribution of vibrations in different directions and at different frequencies with respect to the above and below positions would be that different particles of different masses would act differently under different frequencies and the same should apply to different mass quantities enclosed in different mold patterns with varying volumes. .

In connection with the vibration of the pulp described above, it has been shown in certain applications that a particularly good packing of the pulp is achieved if both the upper mold and the lower mold are tilted relative to the horizontal. This procedure gives a particularly good result in molds with depth variations in different parts. The tilt is selected by the most suitable ·· min for those parts which are at their deepest, whereby during vibration the mass tends to move in the direction of the tilt, i.e. in the direction of the deepest parts. The inclination is chosen, for example, so as to obtain a homogeneous density in the mass, i.e. to counteract the inferior packaging which normally occurs in the lower parts.

The inclination is achieved, for example, by pivoting), suspended molds, in which, however, the compression direction can be chosen either obliquely to the vertical as opposed to the inclination of the upper and lower molds or to a straightness so that both the upper and lower molds are constantly inclined.

Claims (7)

15 64762 A method of making a variety of products in a mold from a mixture of plastic and a relatively large portion of filler, wherein the lower mold (16) in the mold is filled to a predetermined level with the mixture and the upper mold (21) is pressed against the filled mixture by a press head (27) (21) for pressing into the lower mold (16), in addition to which the upper and lower mold are subjected to vibration by a vibrating device (28, 29), comprising the steps of: (a) lowering the upper mold (21) per free mass surface of the filled mixture; (b) during the second compression cycle, the mold is subjected to a relatively significantly higher compression pressure to finally compress the mixture, with both the upper mold and the lower mold (16) being vibrated during both compression cycles; forces transverse to said compression direction, the vibration forces transverse to the compression direction having two transverse directions and the vibrations of the lower mold opposite to the vibration forces of the upper mold, characterized in that the vibration action from the upper mold (21) . Method according to Claim 1, characterized in that the vibrating effect on at least one of the upper mold (21) and the lower mold (16) consists of superimposed oscillations having at least two different frequencies. A method according to claim 2, characterized in that the vibration effect on the upper mold (21) and the lower mold (16), respectively, has an amplitude which in selected directions exceeds the amplitude of the other directions. 16 6 4 7 6 2 Method according to Claims 1 to 3, characterized in that the upper mold (21) and the lower mold (16) are kept inclined relative to the compression direction. Method according to Claim 4, characterized in that the vibrating effect is directed to the lowest part of the lower mold (16). 1. Forms for the manufacture of a product form for the manufacture of plastics or for the manufacture of plastics, for example, for the manufacture of bleaching products and for the manufacture of overheads (21) impresses with the respective means for pressing the press (27), for pressing the mold (21) and the underform (16), varying the vibrator arrangements (28, 29), and using the vibrating, under-forming vibration; (a) the use of pressurizers in the form of a pressurized formulation (21) the use of bleaching agents in the form of vibration in the case of a single-compression strip, the colors under the pressure of the pressure shield are formed by the under-shape (16) of the vibration crusher, <- -tecknat därav, att vibrationsverkan pä överformen (21) Skei: med en frekvens som avviker frän pä underformen riktad Slagkraft.