Moulding device and production process
A production process includes introducing the material to be moulded into a mould, placing the mould in an envelope comprising a vacuum port; creating a low pressure in the envelope by formation of a gas flow through the vacuum port; deforming the mould; stopping the gas flow; and applying pressure on at least a portion of the mould, optionally with interposition of the envelope, at least after the gas flow is stopped.
1. A production process of a concrete moulded part, comprising:
pouring unset concrete into a flexible mould, the flexible mould comprising a bottom shell and a top shell on the bottom shell closing the flexible mould, the concrete being confined in the flexible mould;
placing the flexible mould in a flexible envelope comprising a vacuum port;
creating a low pressure in the flexible envelope formed by a gas flow out of the flexible envelope passing through the vacuum port;
deforming the flexible mould by a deforming member located beneath the mould, said deforming member acting on the envelope to deform the flexible mould, the flexible mould lying horizontally when the deforming member is not deforming the mould;
stopping the gas flow out of the flexible envelope with an obturating element when the low pressure has been created in the flexible envelope;
applying pressure, by a pressure module different from the flexible mould, the envelope and the deforming member, on at least a portion of the flexible mould, optionally with interposition of the flexible envelope, at least after the gas flow out of the flexible envelope has stopped, said pressure being applied on the at least a portion of the flexible mould so that the top shell is prevented from shifting relative to the bottom shell, and
after the concrete has set, removing the mould from the envelope and removing the concrete moulded part from the flexible mould.
2. The process according to claim 1 , wherein the vacuum port is connected to a vacuum pump using a connecting element, wherein creating the low pressure comprises turning the vacuum pump on and wherein stopping the gas flow comprises turning the vacuum pump off.
3. The process according to claim 2 , wherein stopping the gas flow comprises at least partially obturating the connecting element.
4. The process according to claim 1 , wherein the mould comprises at least first and second opposing faces, to which the deforming member applies a first pressure on the flexible mould, with interposition of the flexible envelope, on the side of the first face, and to which said pressure module applies a second pressure on the flexible mould, with interposition of the flexible envelope, on the side of the second face.
5. The process according to claim 4 , wherein said pressure module applies a substantially uniform second pressure on the flexible mould, with interruption of the envelope, over more than half of the second face.
6. The process according to claim 1 , wherein applying pressure comprises placing at least one load on at least a portion of the flexible mould, optionally with interposition of the flexible envelope.
7. The process according to claim 1 , wherein the pressure module includes a load having a mass greater than 1 kg.
8. The process according to claim 7 , wherein the load is a container that includes a plurality of juxtaposed compartments.
9. The process according to claim 1 , wherein the deforming member is a jack or a template.