Method and compositions for producing polymer blends

A method of producing a pellet mixture having a predetermined concentration of a first additive, a predetermined concentration of a second additive, and a predetermined concentration of caprolactam, said method comprising the steps of:

• incorporating the first additive and the second additive into a polymer resin having a melt point, wherein said incorporating is performed at a temperature above the melt point of the polymer resin, to produce a first polymer compound having a concentration of the first additive greater than the predetermined concentration of the first additive, a concentration of the second additive greater than the predetermined concentration of the second additive, and a concentration of caprolactam greater than the predetermined concentration of caprolactam, wherein the first additive is a lubricant selected from the group consisting of ethylene bis stearamide, metallic stearates, and metallic fatty acids, and the second additive is a heat stabilizer selected from the group consisting of metallic halides;
• pelletizing the first polymer compound to produce a first plurality of pellets;
• and
• mixing the first plurality of pellets with a second plurality of pellets, the second plurality of pellets consisting essentially of nylon 6, to produce a pellet mixture, wherein the second plurality of pellets comprises the polymer resin, wherein the pellet mixture comprises the predetermined concentration of the first additive, the predetermined concentration of the second additive, and the predetermined concentration of caprolactam.

A masterbatch comprising:

• a nylon resin having a melt point, wherein the nylon resin is a nylon 6 resin having an extractable content of from 2 wt. % to 5 wt. %, a solution viscosity of from 45 FAV to 65 FAV;
• one or more heat stabilizers, said one or more heat stabilizers comprising from 0.3 wt. % to 12 wt. % of the masterbatch;
• one or more lubricants, said one or more lubricants comprising from 0.5 wt. % to 6 wt. % of the masterbatch;
• and
• caprolactam, wherein the caprolactam comprises from 5 wt. % to 16 wt. % of the masterbatch;
• wherein the one or more heat stabilizers and one or more lubricants are incorporated into the nylon resin at a temperature above the melt point to form the masterbatch.

A masterbatch comprising:

• a nylon resin having a melt point, wherein the nylon resin is a nylon 6 resin having an extractable content of from 2 wt. % to 5.5 wt. % and a solution viscosity of from 40 FAV to 60 FAV;
• one or more heat stabilizers, said one or more heat stabilizers comprising from 0.3 wt. % to 12 wt. % of the masterbatch;
• one or more lubricants, said one or more lubricants comprising from 0.5 wt. % to 6 wt. % of the masterbatch;
• and
• caprolactam, wherein the caprolactam comprises from 0.5 wt. % to 10 wt. % of the masterbatch;
• wherein the one or more heat stabilizers and one or more lubricants are incorporated into the nylon resin at a temperature above the melt point to form the masterbatch.