Patent Application
20180257259
The present invention relates to an additive manufacturing process for the manufacture of composite materials. More particularly, but not exclusively, the present invention relates to an additive manufacturing process for the manufacture of reinforced composite building panels, roof or floor trusses and beams, columns and cladding.
Additive manufacturing processes such as 3D printing have been proposed and extensively used for the manufacture of many small scale items, though difficulties have been encountered in using such processes for the manufacture of larger scale items, such as building panels, which presently can be time consuming and labour intensive to form. Also, some items previously formed with 3D printing processes have lacked sufficient structural strength for use in applications having minimum strength requirements or in applications having the satisfy the relevant Building Code of Construction applicable to a construction project.
Examples of the invention seek to solve, or at least ameliorate, one or more disadvantages of previously proposed additive manufacturing processes.
According to a first aspect of the present invention there is provided an additive manufacturing process for the manufacture of a body from composite materials, including the steps of:
According to a preferred embodiment of the invention, the support structure is inclined and a closing member is provided, the support structure and the closing member cooperating to form a mould cavity in which the composite material is formed. Preferably, the closing member is applied progressively as the matrix material is applied.
Preferably, the nozzle is part of a movable printing head.
The process may further include the step of bringing a shaping member into contact with the matrix material to obtain a desired surface contour. The shaping member may be in the form of a scraping tool.
The step of providing a support structure can include arranging a fabric material adjacent a support structure and applying a hardening agent to the fabric.
Preferably, the reinforcing material is formed with standoffs to maintain a separation from the support structure.
Preferably, the matrix material is heated during application. The support structure can be heated to heat the matrix material. In some embodiments, the reinforcing material conducts electricity and the matrix material is heated by applying an electrical current to the reinforcing material.
According to some embodiments, the matrix material is applied so as to encapsulate the reinforcing material.
The process can further include the step of rotating the support structure to form three dimensional objects. In some example, the support structure has a three dimensional form. In other example, the support structure is in the form of shutterings.
The support structure can be formed with recesses in which the reinforcing material can be received. In some examples, the support structure is in the form of a corrugated sheet having valleys in which the reinforcing material can be received. Preferably, the support structure is formed from a mouldable composite material. The support structure can be in the form of magnetic panelling.
The process can further include the step of prestressing the reinforcement material prior to applying the matrix material.
In some example, the composite material is in the form of a panel or truss. Such a panel can be provided with coupling means for coupling a plurality of like panels together.
Preferably, the reinforcement material is selected from a group including steel, graphene, carbon fibre or glass fibre. The reinforcement material may be a mesh or honeycomb material.
In some embodiments, the reinforcement material is applied in layers. The matrix material can include cement, polyethylene or polyurethane.
The process can further include the step of adding a filling material, which can be formed of polystyrene.
Preferred embodiments of the invention will be further described, by way of non-limiting example only, with reference to the accompanying drawings in which:
With reference to
In the embodiments shown in
In some forms, the matrix material will be highly viscous and/or set very quickly so that closing members 16 are not required. In such embodiments, the matrix material may be smoothed or wiped during application to provide a smooth finish. Smoothing may be performed by a scraper or a roller.
In some forms, the support structure 12 is inclined at an angle to horizontal, which will be selected having regard to the body to be formed and other process constraints.
The matrix material applied in step (C) is applied from a nozzle which is part of a movable printing head, such as a printing head of a 3D printing machine. It will be appreciated that for convenience the nozzle is movable to apply or deposit the material, though in other forms the composite material may move relative to a stationary nozzle, or both the composite material and the nozzle may move relative to each other.
The printing head preferably includes a shaping member for contouring the composite material as it is formed and the process can further include the step (D) of bringing the shaping member into contact with the matrix material to obtain a desired surface contour. In one form, the shaping member is in the form of a scraping tool. In other forms, the shaping member may be a roller or cut or otherwise machine the matrix material.
In some embodiments, in particular those in which the matrix material is built up in layers, a rotating brush may be provided to clear material build-up from the reinforcement material.
To ensure fusion between subsequent layers of the matrix material (where applicable), the matrix material may be heated during application. To this end, a heat gun using warm air, induction heating, infrared heating or UV lamps may be provided. The support structure may be heated to heat the matrix material or, in other forms such as those where the reinforcing material conducts electricity, the matrix material may be heated by applying an electrical current to the reinforcing material.
In embodiments using polymer matrix materials, the polymer may be fed to the nozzle as plastic wire or the nozzle may be part of a printing head configured for receiving plastic pallets and heat mixing them in, or in close proximity to, the printing head. In such an embodiment, the print head may include heating elements for melting the pellets and an auger for advancing the melted polymer toward the nozzle. Advantageously, polymer pellets, such as recycled polymer pellets, may be used, thereby reducing the cost of forming the body. Previously, recycled pellets have been undesirable for use in additive manufacturing processes due to their lack of accuracy, though the described process can utilise such materials due to the way the matrix material is applied.
In a preferred form the matrix material encapsulates, either completely or partially, the reinforcing material. In this regard, the matrix material may be applied and built up in layers so as to encapsulate the reinforcing material. In other forms, the matrix material may not completely encapsulate the reinforcement material to allow subsequent layers to be formed or joined together. To facilitate subsequent layers bonding together, the reinforcement may be configured for interlocking engagement with other like sections of reinforcement material.
In one form, the support structure may be in three dimensional form so that three dimensional objects can be formed. In other forms, the process can further include the step of rotating the support structure to form three dimensional objects. Advantageously, three dimensional components such as building elements may be formed, as can items such as aeroplane or helicopter bodies, boat hulls or car bodies. Also, the composite material formed by the described method may be in the form of a panel or truss having a reinforcing member encapsulated within a protective matrix material. It may also be provided with coupling means for coupling a plurality of like components together.
The support structure may take many forms and, in one example, may be in the form of shutterings. Also, the support structure may include magnetic panelling configured to be held in close proximity to the reinforcement material when in a metallic form. In other forms, the support structure may be progressively assembled as the matrix is applied so as to progressively build up a large scale object, such as a multistorey dwelling for example.
In embodiments such as that shown in
Many different materials may be used for the reinforcement material, for example steel, graphene, carbon fibre or glass fibre. Fibrous materials such as jute, hemp or sisal may also be used and those skilled in the art will appreciate that many other commercially available materials may similarly be used. Also, the reinforcement material may take many forms such as rods like conventional concrete reinforcement rods, mesh or a honeycomb material, and may be in the form of metal or non-metal materials and may be a mesh or non-meshed material. In some examples, the reinforcement material is applied in layers, which may be configured for interlocking engagement with each other. The reinforcement material may be prestressing prior to applying the matrix material or post stressed after the matrix has been applied. So as to provide a composite material having the characteristics for a desired application, the reinforcement material may be prestressed/post-stressed to different degrees in different directions.
It will be appreciated that the matrix material may take many forms, such as for example, cement, plastics such as polyethylene or polyurethane, or combinations thereof. Due to contraction on cooling, polymer matrix materials are particularly useful as they interact with the reinforcement material to provide a strong body. In a preferred example, the matrix material is LDPE, which provides a formed body that can be deformed to a required shape.
The described method may also include the step of adding a filling material, such as polystyrene to fill voids in the composite material. In other forms, the support structure 12, 112 may be configured to reduce the volume of matrix material required and reduce the weight of the body formed. In one example, the support structure can include recesses, such as grooves or channels machined in the support structure, in which the reinforcing material can be received. In other examples, fillers may be applied against the support structure to occupy the volume of matrix material. In one example, the support structure is in the form of a corrugated sheet having valleys in which the reinforcing material can be received. The support structure may also have a three dimensional form to reduce the volume of matrix material required. In this regard, the support structure may be formed of a lightweight plastic or moulded paper-based product, such as paper mache for example, and may be moulded or pressed into shape during forming.
The embodiments have been described by way of example only and modifications are possible within the scope of the invention disclosed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015903536 | Aug 2015 | AU | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/AU2016/050813 | 8/30/2016 | WO | 00 |
