Process for lightening plasterboards
View Patent ↗Process for the manufacture of plasterboards exhibiting a core density of less than 0.77 comprising the stages of the formation of a foam from water and a surfactant composed of at least one alkyl sulphate of formula H(CH 2 ) n OSO 3 − M + , in which n is a number between 6 and 16, M is a monovalent cation and the mean number of carbon atoms n m is from 9 to 10, and the introduction of the foam obtained into a plaster slurry, characterized in that the amount of surfactant introduced does not exceed 0.32 g/l of plaster slurry. Application to the manufacture of lightened plasterboards.
1. A process for manufacture of plasterboards exhibiting a core density of less than 0.77, the process comprising:
forming a foam from water and a surfactant comprising at least one alkyl sulphate of formula H(CH 2 ) n OSO 3 − M + , in which n is a number between 6 and 16, M is a monovalent cation and a mean number of carbon atoms n m is from 9 to 10, and
introducing the foam into a plaster slurry,
wherein the amount of surfactant introduced does not exceed 0.32 g/liter of plaster slurry,
wherein the surfactant composition is free from alkyl ether sulphates.
2. The process according to claim 1 , in which the amount of surfactant is less than 0.24 g/l of plaster slurry.
3. The process according to claim 1 , in which the plasterboard produced exhibits a compressive strength of greater than 2 MPa.
4. The process according to claim 1 , in which the surfactant comprises 5 to 60% by weight of dodecyl sulphate.
5. The process according to claim 1 , in which the surfactant comprises 40 to 95% by weight of decyl sulphate.
6. The process according to claim 1 , in which the surfactant comprises 5 to 60% by weight of octyl sulphate.
7. The process according to claim 1 , in which M is chosen from sodium, potassium, magnesium and ammonium.
8. The process according to claim 1 , in which the surfactant comprises 5 to 25% by weight of sodium octyl sulphate and 75 to 95% by weight of sodium decyl sulphate.
9. The process according to claim 1 , in which the surfactant comprises 5 to 15% by weight of sodium octyl sulphate and 85 to 95% by weight of sodium decyl sulphate.
10. The process according to claim 1 , in which the surfactant additionally comprises a sequestering agent.
11. The process according to claim 1 , in which the surfactant additionally comprises a hydrotropic agent.
12. A method for lightening plasterboards using a surfactant comprising at least one alkyl sulphate of a formula H(CH 2 ) n OSO 3 − M + , in which n is a number between 6 and 16, M is monovalent cation and a mean number of carbon atoms n m is from 9 to 10, wherein the method includes mixing a foam of surfactant and water with a plaster slurry, the amount of surfactant used being less than 0.32 g/l of plaster slurry,
wherein the surfactant composition is free from alkyl ether sulphates.
13. The method according to claim 12 , in which the plasterboard exhibits a core density of less than 0.77.
14. A process for manufacture of plasterboards exhibiting a core density of less than 0.77, the process comprising:
forming a foam from water and a surfactant comprising at least one alkyl sulphate of formula H(CH 2 ) n OSO 3 − M + , in which n is a number between 6 and 16, M is a monovalent cation and a mean number of carbon atoms n m is from 9 to 10, and
introducing the foam into a plaster slurry,
wherein the amount of surfactant introduced does not exceed 0.32 g/liter of plaster slurry,
wherein the surfactant comprises 5 to 60% by weight of dodecyl sulphate.
15. The process according to claim 14 , in which the amount of surfactant is less than 0.24 g/l of plaster slurry.
16. The process according to claim 14 , in which the plasterboard produced exhibits a compressive strength of greater than 2 MPa.
17. The process according to claim 14 , in which the surfactant comprises 40 to 95% by weight of decyl sulphate.
18. The process according to claim 14 , in which the surfactant comprises 5 to 60% by weight of octyl sulphate.
19. The process according to claim 14 , in which M is chosen from sodium, potassium, magnesium and ammonium.
20. The process according to claim 14 , in which the surfactant additionally comprises a sequestering agent.
21. The process according to claim 14 , in which the surfactant additionally comprises a hydrotropic agent.