Producing yarn
A process for the production of a yarn is disclosed, the process comprising providing a bundle comprising continuous filaments of a thermoplastic polymer, contacting the bundle with a sliver comprising fibers of a heat resistant material to form a mixed bundle, and applying a gas jet to the mixed bundle to distribute the fibers of the heat resistant material in the bundle. Also disclosed are yarns comprising filaments of a thermoplastic polymer and fibers of a heat resistant material, wherein the fibers are distributed between and among the filaments. Preferably, the heat resistant material is a non-thermoplastic polymer, especially an aramid. Yarns according to the invention find use in technical fabrics especially transmission belts.
1. A process for the production of a yarn, the process comprising
providing a bundle comprising continuous filaments of a thermoplastic polymer,
contacting the bundle with a sliver comprising fibres of a heat resistant material,
combining the filaments and the sliver in a drawing step to produce a single bundle, and
applying a gas jet to the single bundle to distribute the fibres of the heat resistant material in the bundle, thereby distributing the fibres between and among the filaments.
2. A process as claimed in claim 1 , wherein the heat resistant material is selected from glass, carbon or a non-thermoplastic polymer.
3. A process as claimed in claim 2 , wherein the non-thermoplastic polymer is selected from aramid, polyamide-imide, polyimide-amide, liquid crystal polymer, PVA, P84, PBI or PTFE.
4. A process as claimed in claim 2 , wherein the thermoplastic polymer is a texturized thermoplastic polymer.
5. A process as claimed in claim 1 , further comprising at least one activation step.
6. A process as claimed in claim 1 , wherein the thermoplastic polymer is selected from polyamide, polyester, PBT, poly ether ether ketone, poly ether imide or polyolefin.
7. A process as claimed in claim 1 , wherein the single bundle comprises the fibres of the heat resistant material in an amount of between 5 and 75% by weight.
8. A process as claimed in claim 1 , wherein the filaments of thermoplastic are in the range 33 to 2000 decitex.
9. A process as claimed in claim 1 , wherein the length of the fibres of the heat resistant material is between 10 mm and 200 mm.
10. A process as claimed in claim 1 , wherein the drawing step is performed on a drawing frame.