VAARA JAN (SE)
KROGAGER MAX (SE)
VAARA JAN (SE)
| WO1995014563A1 | 1995-06-01 |
| US2517902A | 1950-08-08 | |||
| DE8711336U1 | 1987-10-22 | |||
| GB2292332A | 1996-02-21 | |||
| EP0008012A1 | 1980-02-20 | |||
| US3964534A | 1976-06-22 |
| 1. | The method of producing mould sections or mould inserts of the type that are used as internal support and mould parts during the manufacturing of products made from composite materials such as fibre laminate armouring, polymers, etc. inclusive of the final state of empty spaces, such as integrated support sections, builtin tank areas and such as are similar, wherein each mould section or mould insert is manufactured using a finely particulate and, in and of itself, hard material contained in a gas tight bag given a desired exterior form in a casting mould or equivalent thereto, while the material of this containing bag is also vacuum sealed such that the finely particulate material forms a firmly cohesive unit, after which the bag is given a gas tight seal. |
| 2. | The manufacture of such products as composite materials, that include empty spaces in their final state, such as integrated support sections or other integrated empty spaces, uses mould sections or mould inserts produced in accordance with said method described in claim 1, w h e r e i n they consist of a cohesive unit with the desired exterior dimensions induced by external compression and vacuum sealing of the firm unit formed in a gas tight, and hermetically sealed after vacuum sealing, bag containing the mould insert, itself, consisting of a fine particulate material. |
| 3. | Regarding said mould insert, in accordance with claim 2, wherein a fine particulate material is utilised such as sand, metallic powder or some equivalent thereto. |
| 4. | Regarding said mould insert, in accordance with claim 2 or 3, w h e r e i n the gas tight bag material is an aluminium plasticbased foil material. |
| 5. | The method of producing such products as composite materials, that include empty spaces in their final state, such as integrated support sections, builtin tank areas etc., wherein said empty spaces under the design of and up to and including the completed final hardening of the product, shall be defined in accordance with claims 1 through 3 regarding the manufactured mould inserts, consisting of a gas tight bag or other vessel containing compressed and vacuum sealed material, itself a hard particulate substance, which, after the cooling and hardening of the composite material, shall be emptied from the vessel containing the particulate material by puncturing said vessel through one of the openings, appropriately remaining, in the final product, through which said vessel or bag may also then be removed. |
In the manufacture of armoured plastic composite products it is common that large interior areas are often strengthened with reinforcement sections such as can have the form of channel irons integrated into the product. It is also common that final products have empty internal spaces, also integrated with the product, such as tanks or parts of such. Interior support sections or mould sections define these empty spaces in the final product during the manufacturing stage. These mould sections, usually referred to as mould inserts, shall also define the interior cavity during the manufacturing stage and must have a casting mould allowing their removal when the desired product has cooled and hardened. The need to remove such mould inserts from the final product has often affected their geometry and compelled present technology to produce each mould insert in the form of several connectable units. This has led to mould inserts becoming expensive although they are reusable within production.
The subject invention treats a new method of manufacturing said mould inserts in the form of connectable units intended for one-time usage but which are so easily, and most of all inexpensively, produced that their use shall become more economical than all earlier types of mould inserts used. The mould inserts, according to the subject invention, are also easy to remove from the cavities of the final product by virtue of their special design, and the openings through which the mould inserts are to be removed need not have an exit area equalling the cross-sectional area of each mould insert. The mould inserts, produced in accordance with the subject invention, need not be designed with any special clearance grooves along the direction of removal.
Thus, the relevant mould sections or mould inserts, according to the subject invention, shall be produced of a particulate material, in itself hard, that can consist, e. g. , of sand, metallic powder or another similar product and that, contained in a gas-tight bag, gives the mould insert the desired exterior shape in a casting mould or device equivalent thereto while the bag is vacuum sealed such that the particulate material forms a body of firm cohesion, after which the opening used for the vacuum sealing of the bag is hermetically sealed.
The vacuum sealing of particulate material in hermetically sealed bags occurs often in the food industry, but there it is most often in the interest of increasing the shelf life of a product, even if on were to be able to assert that such packaging, e. g. that of ground coffee, already has a good shelf life as long as the surround air-tight bag is intact.
As indicated above, many different types of particulate material can be used as mould insert material. The more essential requirements placed on the material in question concern the appropriate particle size, shape and sufficient hardness, of the material itself, as well as it being non-reactive. Similarly, as regards the bag material it must be easily sealed because both the opening through which the particulate material is inserted and the opening for the vacuum sealing must be sealed and it shall gas tight and must have sufficient strength, in itself. A good means of sealing foil material is preferably by welding. Thus, it is advantageous if the foil material is easily welded. Therefore, aluminium plastic foil of appropriate thickness is a preferable bag material.
One of the considerable advantages of the subject invention is the simplicity with which mould inserts of this type can be removed when the final product has properly cooled and hardened. At that stage, one punctures the surrounding gas tight bag whereupon the cohesion of the mould insert material collapses when the vacuum is ruptured. The particulate material can be poured out as soon as this has occurred. It should be advantageous, towards this end, to use an opening that is clearly less than the greatest cross sectional area of the mould insert.
The bag material shall also be able to be removed in the same method from the now empty cavity, presuming that one has selected a bag material that shall not automatically bind with the base material of the final main design. The invention has been defined if the following patent claims and, as this regards a fundamental production concept and not detailed design, it has not been regarded as necessary to illustrate said claims with special figures.