Material and method and device for producing the same
View Patent ↗The invention relates to a material which consists essentially of sand and polymers as well as optionally, a small quantity of aggregates. The invention also relates to a method for producing this material, comprising the following steps: producing a hot molten mixture consisting of sand and polymers; introducing said molten mixture into a mould; cooling the molten mixture under pressure until the molten mixture hardens in the mould. The material can be used e.g. for producing building blocks, pavement slabs, manhole covers, housings in electrical engineering and insulators for high-voltage applications.
1. A process to manufacture a material that consists mainly of sand and polymers, comprising:
creating a hot fusion mixture of sand and polymers;
placing the fusion mixture into a mold;
cooling the fusion mixture under pressure of from 1 to 40 kPa until it hardens in the mold; and
further cooling the hardened material under normal pressure.
2. A process as in claim 1 , further comprising cooling the material to about 30° C. after hardening of the fusion mixture under normal pressure.
3. A process as in claim 1 , wherein the material comprises about 50% Sand and of at least 15% Polymer with respect to the entire mass.
4. A process as in claim 1 , wherein the cooling step further comprises cooling the fusion mixture in the mold at a temperature of about 60° C. to 100° C.
5. A process as In claim 1 , wherein the step of creating the hot fusion mixture includes chopping waste plastic to prepare a polymer granulate.
6. A process as in claim 1 , wherein the sand possesses a grain size of from 0.5 to 0.9 mm.
7. A process as in claim 1 , wherein the step of creating the hot fusion mixture includes the following steps:
heating the sand to a temperature of from about 90° C. to about a maximum of 800° C.;
adding the sand and the polymers to a mixing vat while maintaining a mixing temperature that is above the melting temperature of the polymer; and
mixing the sand and the polymer to create the hot fusion mixture.
8. A process as in claim 7 , further comprising adding polymers to the heated sand with constant stirring until the portion of polymer is 15% to 50% of the overall mass of the fusion mixture.
9. A process as in claim 7 , further comprising adding heated sand to the polymers with constant stirring until the portion of sand is 50% to 85% of the overall mass of the fusion mixture.
10. A process as in claim 9 , further comprising electrically discharging the heated sand before adding the heated sand to the polymers.
11. A process as in claim 7 , further comprising heating the polymer to its melting point before it is mixed with the sand.
12. A process as in claim 1 , wherein a granulate mixture of sand and polymers is heated to create the hot fusion mixture.
13. A process as in claim 1 , further comprising Adding one or more of the following additives to the hot fusion mixture: organic or inorganic fibers; dyes; chemical softeners; plasticizers; lubricants; silicates.
14. A process as in claim 1 , further comprising inserting fixed elements into the material during the cooling step under pressure before it hardens in order to secure them into the material by form fit.