WO2015057173A1

WO2015057173A1 - Process for the manufacture of vessel models using expanded polystyrene and epoxy material

Info

Publication number: WO2015057173A1
Application number: PCT/SI2013/000061
Authority: WO
Inventors: Roman KOGOJ
Original assignee: Seaway Yachts, D.O.O.
Priority date: 2013-10-17
Filing date: 2013-10-25
Publication date: 2015-04-23
Also published as: SI24509A

Abstract

The process for the manufacture of vessel models using expanded polystyrene and epoxy materials. The proposed invention refers to the use of expanded polystyrene and epoxy materials for the manufacture of vessel models. The process involves the design of the model's geometry, the preparation and fixing of the polystyrene blank, CNC machine assisted milling of the blank, transforming a rough version of the model into its milled version that is up to 9 mm shallower than previously, the processing of the milled model to remove minor imperfections; the laminating of the model with epoxy resin that does not contain styrene, the cleaning and sanding of the pre-laminated surface to eliminate any imperfections from the laminating procedure, the application of epoxy paste, rough and fine sanding of epoxy paste using a CNC machine; corrections and final fine processing of the model, the application of varnish in at least four uniform coatings so that the total thickness varnish layer is up to 0.8mm, finished by fine polishing of the surface and wiping with an antistatic cloth.

Description

Process for the manufacture of vessel models using expanded polystyrene and epoxy material

Subject of the invention

The subject of the invention is te the process for the manufacture of vessel models using expanded polystyrene and epoxy material. The aforementioned materials enable the use of CNC machines during the individual stages of the process. When the design department finishes the sample drawing of the model, it will have to be redrawn using the Catia software. This step is crucial for further manufacture of the vessel model, for the said software provides us with all of the information required to create milling programmes that will be carried out automatically by the CNC machine during the individual stages of the process.

The invention falls within the field of vessel manufacture. Technical problem

The technical problem addressed and resolved by the invention is the use of expanded polystyrene and epoxy material for the manufacture of vessel models, enabling a controlled manufacturing process; in addition to that, the use of expanded polystyrene and epoxy material makes it possible to easily remove potential errors and make multiple alterations of the shape/design that are commonly required in the vessel manufacturing process.

State of the art

The established process for the manufacture of vessel models was building the vessels manually using wooden constructions and polyurethane foam. A model had to be put together with great precision, which was very time-consuming and it was extremely difficult to change the geometry or to rectify any errors that took place in the process. In practice, it turned out that such procedures took too long, were excessively expensive, making it hard to monitor and control the process underway, not to mention to correct any mistakes that were made during the manufacturing procedure. The above technical problem is resolved using the process that is the subject of the invention, where expanded polystyrene and epoxy material are used to manufacture the vessel model or mould. Solution of the technical problem

The technical problem as described in the previous chapter is solved by using the process according to the invention.

The process for the manufacture of models by using expanded polystyrene and epoxy material includes:

- the manufacture of the model's entire geometry and the preparation of the blank for the vessel model;

- the cutting of expanded polystyrene using hot wire into pieces/sections that are then numbered and should correspond to the numbers on the blueprint ensuring correct assembly of the model;

- preparation of a base plate on which battens are fixed with screws, which allow for a greater solidity of the model; wooden plates, for instance QSB, are then glued and fixed with screws to these battens, which serve as the base for the expanded polystyrene;

- gluing of expanded polystyrene or previously prepared individual polystyrene sections onto the base plate using polyurethane foam. Special attention should be made that the contact between the blocks/sections/pieces of expanded polystyrene is as tight as possible, the gap never exceeding 10mm;

- milling of the model thus assembled using the CNC machine, transforming the roughly assembled model into a milled model that is 9mm shallower than previously - any insufficient thicknesses, i.e. less than 9mm are compensated by adding woven Roving fabric and epoxy paste;

- manual processing of the milled model to remove minor imperfections, such as the filling in of contact gaps between the blocks or individual pieces of expanded polystyrene, surface grinding;

- laminating of the model using epoxy resin that does not contain styrene and is therefore well suited for polystyrene because it does not dissolve it, and with it two layers of Roving 500 fabric. Special care should be taken during the laminating process to avoid any air bubbles from appearing underneath the laminate layers, because this can present a hindrance at later stages. When the laminating process is finished, the minimum waiting period before the next procedure is 12 hours;

- cleaning and surface grinding of pre-laminated surfaces to remove any imperfections from the laminating stage; - application of epoxy paste using an applicator. The paste can be applied either manually or using a CNC machine, depending on the geometry of the model. Usually, machine application is used for open models, such as hulls. During this process, care must be taken when applying the paste to avoid the creation of air bubbles, excessive quantities of paste, and one must be mindful of maintaining the right ratio of the paste/solidifier components. Before any further processing can take place, a waiting period of up to 20 hours is required;

- milling of epoxy paste using a CNC machine. First, the paste is milled roughly. Once this has been done, it must be checked whether the thickness of the applied paste is sufficient on all of the model's surfaces. If not, this is rectified; either by using the same paste used previously, or epoxy putty, which dries faster, but may only be used to address minor blemishes. When the corrections have sufficiently dried, fine milling can begin;

- this milling stage over, the model is checked whether everything has been milled correctly, whether all of the markers have been made and whether the surface itself is free from any blemishes;

- the final manual processing of the model starts by surface grinding using sandpaper - granulation 80, the gluing of insertions and the creation of curvatures. The whole model is covered with control paint making it easier to distinguish which surfaces have been sanded and which not. This is followed by the application of putty, which is then sanded with paper - granulation 120;

- application of varnish using handheld airbrushes, four even coatings, so that the total thickness of the varnish layer is up to 0.8 mm. On the following day, the model is covered with control paint, followed by sanding with paper granulation 240. After that, any tiny holes are filled in with varnish and then sanded with papers - granulations of 500, 800, 1200 and 1500. Between the individual sanding operations, the model is cleaned each time and painted with control paint. After the sanding, the model is polished, first using coarse polishing paste and then fine paste. At the very end, the model is wiped thoroughly with an antistatic cloth.

The model may also feature non-slip deck covering. Depending on the size of the model, the required number of polyester plates with 1.5mm thickness is cast. Using a CNC machine, the desired end shapes of the non-slip deck coverings are milled. These deck coverings are then glued onto the intended surfaces of the model before the varnishing stage. The gluing procedure is as follows: the surface of the model is thoroughly cleaned; the outline of the non-slip deck covering is drawn and this surface is then protected with masking tape; vacuum double sided tape is then applied to the masking tape, while felt, plastic film, glue and vacuum suction cups are made ready; the non-slip deck covering is thoroughly cleaned on the side that is to be glued, while a coat of parting film is applied on the coarse side; after that, glue is applied and the non-slip deck covering is placed on its intended location; on the edge, felt is placed and this is then covered with vinyl foil; a small hole is made where felt has been placed and the vacuum suction cup is positioned over it; it is checked that the vacuum is indeed airtight and the deck covering is left under the vacuum for around 30 minutes to allow the glue to dry.

Once the non-slip deck covering have been glued to the surface of the model, it is varnished using handheld airbrushes and during this process, the non-slip deck covering surface can be protected by covering with vinyl foil.

The use of the abovementioned materials makes it possible to carry out individual manufacturing stages with a CNC machine, resulting in controlled and faster manufacture of the model. Any CNC machine milling operations require special programming adapted to the particular model so that the milling can be fully automated. Once the programmes are ready, the CNC machine can carry out milling operations 24/7. A CNC machine is able to finish a model much faster than this would be possible using a manual process. The automated modelling manufacturing process also allows for a much safer working environment for the operator, for he or she is not in direct contact with the machine's vital parts.

In summary, the characteristics of the process that is the subject of the invention include the following: the design of the model's geometry, the preparation and fixing of the polystyrene blank, CNC machine assisted milling of the blank, transforming a rough version of the model into its milled version that is up to 9 mm shallower than previously, the processing of the milled model to remove minor imperfections; the laminating of the model with epoxy resin that does not contain styrene, the cleaning and sanding of the pre-laminated surface to eliminate any imperfections from the laminating procedure, the application of epoxy paste, coarse and fine sanding of epoxy paste using a CNC machine; corrections and final fine processing of the model, the application of varnish in at least four uniform coatings so that the total thickness varnish layer is up to 0.8mm, finished by fine polishing of the surface and wiping with an antistatic cloth.

Claims

-5- Claims

1. The process for the manufacture of vessel models using expanded polystyrene characterised in that the process includes the following steps:

- the design of the model's geometry;

- the preparation and fixing of the polystyrene blank;

- the milling of the model's blank using a CNC machine, transforming a roughly assembled model into a milled model that is up to 9mm shallower than previously;

- the processing of the milled model to eliminate minor imperfections;

- the laminating of the model using epoxy resin that does not contain styrene;

- the cleaning and surface grinding of the pre-laminated surface to eliminate imperfections that might have appeared during the laminating process;

- the application of epoxy paste;

- the rough and fine milling of the epoxy paste using a CNC machine;

- corrections and final fine processing of the model;

- the application of varnish in at least four uniform coatings so that the total thickness of the varnish layer is up to 0.8 mm;

- fine processing and wiping with an antistatic cloth.

2. The process according to claim 1, characterised in that in the case of the inclusion of non-slip deck covering, the latter are glued to their intended locations on the model's surface before the varnishing stage and are protected using plastic film.