Building products
A method of manufacturing a building product from a mix ( 6 ) including particulate material and a thermoplastic binder which comprises heating the mix at least to a temperature at which the thermoplastic binder in the mix liquefies, subjecting the heated thermoplastic mix to a pressing action that shapes the heated mix, and cooling the shaped heated thermoplastic mix to solidify the thermoplastic binder and form the product (FIG. 4 ).
1. A method of manufacturing a building product from a mix including particulate material and a binder, characterized by the binder being a thermoplastic binder which binder is an asphaltenes-containing binder having a penetration of less than about 15 dmm, comprising:
heating the mix including the thermoplastic binder at least to a temperature at which the thermoplastic binder in the mix liquefies;
subjecting the heated thermoplastic mix to a pressing action that shapes the heated mix; and
cooling the shaped heated thermoplastic mix to solidify the thermoplastic binder and form the building product;
wherein the heated thermoplastic mix flows into at least one mould cavity defined by an outer mould frame and in that the outer frame is warmed to prevent solidification of thermoplastic mix adjacent to the outer mould frame;
and further wherein the outer mould frame defines together with dividers an array of mould cavities and in that the dividers are cooled to prevent sticking of thermoplastic mix adjacent to the dividers.
2. The method according to claim 1 , wherein the pressing action is carried out by at least one compacting head and in that the compacting head is subjected to the action of a fluid which prevents sticking of the head to the thermoplastic mix during the pressing action.
3. The method according to claim 1 , wherein the proportion of thermoplastic binder is less than about 30% by weight of the thermoplastic mix.
4. The method according to claim 3 , wherein the proportion of thermoplastic binder is less than about 10% by weight of the thermoplastic mix.
5. The method according to claim 1 , wherein following the pressing action the shaped heated thermoplastic mix is cooled by the action of water.
6. The method according to claim 5 , wherein the heated shaped thermoplastic mix is cooled by immersion in water.
7. The method according to claim 5 , wherein the heated shaped thermoplastic mix is cooled by water sprays.