Claims
- 1. A process for preparing an expanded and extruded solid composition with a matrix which comprises a cellular network formed from a starch-rich product and which contains expanded thermoplastic hollow particles of a homopolymer or copolymer formed from an ethylenically unsaturated monomer or mixture of such monomers, wherein the starting materials for said process include said starch-rich product, said thermoplastic hollow particles, and water, said process comprising:
- mixing said starting materials together to form a mixture in a twin-screw extruder;
- kneading said mixture in said extruder; and
- expanding and extruding said kneaded mixture in said extruder.
- 2. A process according to claim 1, comprising:
- introducing said starting materials at the entry of the twin-screw extruder into the feeding zone at room temperature;
- kneading and compressing said materials in various zones of the extruder, said zones being maintained at a temperature below 100.degree. C. to obtain a kneaded and compressed mass;
- transporting said mass obtained to the exit of the extruder;
- extruding said mass through a die to undergo an expansion and form an extruded product; and
- if necessary, drying said extruded products according to a standard drying process.
- 3. A process according to claim 2, further comprising heating the kneading and compression zones to a temperature ranging from 60.degree. to 80.degree. C.
- 4. A process for preparing an expanded solid composition with a matrix which comprises a cellular network formed from a starch-rich product and which contains expanded thermoplastic hollow particles of a homopolymer or copolymer formed from an ethylenically unsaturated monomer or mixture of such monomers, wherein the starting materials for said process include said starch-rich product, said thermoplastic hollow particles, and water, said process comprising:
- mixing said starting materials together to form a mixture and
- processing said mixture to obtain said expanded solid composition.
- 5. A process as claimed in claim 1, wherein said particles are present in a proportion of 2 to 30% relative to the total weight of said composition.
- 6. A process as claimed in claim 4, wherein said particles are present in a proportion of 2 to 30% relative to the total weight of said composition.
Priority Claims (1)
Number |
Date |
Country |
Kind |
95-06321 |
May 1995 |
FRX |
|
Parent Case Info
This is a division of application Ser. No. 08/654,741, filed May 29, 1996 and now U.S. Pat. No. 5,925,380 the contents of which are incorporated herein by reference.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
3615972 |
Morehouse et al. |
Oct 1971 |
|
5089469 |
Zampino et al. |
Feb 1992 |
|
5196200 |
Wilson et al. |
Mar 1993 |
|
5679361 |
Pradier et al. |
Oct 1997 |
|
Foreign Referenced Citations (5)
Number |
Date |
Country |
0 486 394 |
May 1992 |
EPX |
0 544 349 |
Jun 1993 |
EPX |
0 605 284 |
Jul 1994 |
EPX |
1 594 256 |
Jul 1970 |
FRX |
WO 9208759 |
May 1992 |
WOX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
654741 |
May 1996 |
|