System for producing a fully impregnated thermoplastic prepreg

Patent metadata

Field	Value
Publication number	US-9962888-B2
Application number	US-201715408992-A
Country	US
Kind code	B2
Filing date	Jan 18, 2017
Priority date	Nov 22, 2013
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

According to one embodiment, a system for manufacturing a fully impregnated thermoplastic prepreg includes a mechanism for moving a fabric or mat and a drying mechanism that removes residual moisture from at least one surface of the fabric or mat. The system also includes a resin application mechanism that applies a reactive resin to the fabric or mat and a press mechanism that presses the coated fabric or mat to ensure that the resin fully saturates the fabric or mat. The system further includes a curing oven through which the coated fabric or mat is moved to polymerize the resin and thereby form a thermoplastic polymer so that upon exiting the oven, the fabric or mat is fully impregnated with the thermoplastic polymer. During at least a portion of the process, humidity in the vicinity of the coated fabric or mat is maintained at substantially zero.

First claim

What is claimed is:

1. A method of forming a fully impregnated thermoplastic prepreg product comprising:
moving a fabric or mat from a starting point to an ending point, wherein the fabric or mat is subjected to a plurality of processes and wherein the fabric or mat is in substantially constant movement between the starting point and ending point;
drying the fabric or mat to remove residual moisture from the fabric or mat;
mixing a liquid or molten lactam with a catalyst and an activator via a mixing component to form a reactive resin mixture, the catalyst and activator facilitating in polymerizing the liquid or molten lactam to form a thermoplastic polymer;
applying the reactive resin mixture to the fabric or mat via a resin application die that is positioned above the fabric or mat so that the reactive resin mixture is applied to the fabric or mat as the fabric or mat is passed under the resin application die, the reactive resin mixture having a viscosity of 10 centipoises or less;
blowing, via a gas application mechanism, a moisture-free gas onto one or more surfaces of the fabric or mat after application of the reactive resin mixture and prior to passing the fabric or mat through a curing oven, the moisture-free gas being blown onto the fabric or mat to substantially prevent exposure of the reactive resin mixture to ambient moisture in a surrounding environment;
passing the fabric or mat through a calendar or press to press the reactive resin mixture entirely through the fabric or mat such that the reactive resin mixture fully saturates the fabric or mat; and
passing the fabric or mat through the curing oven to polymerize the reactive resin mixture and thereby form the thermoplastic polymer;
wherein the mixing component and the resin application die are heated to maintain a temperature of the liquid or molten lactam to between 70 and 120 degrees Celsius.

2. The method of claim 1 , wherein a portion of the liquid or molten lactam is mixed with the catalyst in a first tank and a portion of the liquid or molten lactam is mixed with the activator in a second tank that is separate from the first tank, and wherein mixing the liquid or molten lactam with the catalyst and the activator comprises mixing the materials from the first tank and the second tank in the mixing component, wherein the first holding tank and the second holding tank are heated to maintain a temperature of the lactam to between 70 and 120 degrees Celsius.

3. The method of claim 1 , wherein nitrogen gas is applied to the one or more surfaces of the fabric or mat.

4. The method of claim 1 , wherein the curing oven comprises a double belt compression oven.

5. The method of claim 1 , further comprising winding the fully impregnated thermoplastic prepreg into a roll product.

6. The method of claim 1 , wherein greater than 95% of the liquid or molten lactam is polymerized to form the thermoplastic polymer.

7. The method of claim 1 , wherein the liquid or molten lactam comprises caprolactam.

8. A method of forming a fully impregnated thermoplastic prepreg product comprising:
drying a fabric or mat to remove residual moisture from the fabric or mat;
applying a liquid or molten resin to the fabric or mat via a resin application mechanism;
blowing, via a gas application mechanism, a moisture-free gas onto one or more surfaces of the fabric or mat after application of the liquid or molten resin and prior to passing the fabric or mat through a curing oven to substantially prevent exposure of the liquid or molten resin to ambient moisture in a surrounding environment;
passing the fabric or mat through a calendar or press to fully saturate the fabric or mat with the resin; and
passing the fabric or mat through the curing oven to polymerize the resin and thereby form the thermoplastic polymer;
wherein the gas application mechanism is positioned such that the moisture-free gas is blown onto the one or more surfaces of the fabric or mat between the resin application mechanism and the curing oven; and
wherein the above process occurs in a time of less than 10 minutes.

9. The method of claim 8 , further comprising combining a catalyst and an activator with the liquid or molten resin prior to applying the liquid or molten resin to the fabric or mat.

10. The method of claim 8 , wherein the fabric or mat includes sized fibers containing an activator and wherein the method includes applying the liquid or molten resin to the fabric or mat made of the sized fibers.

11. The method of claim 8 , further comprising winding the fully impregnated thermoplastic prepreg into a roll product.

12. The method of claim 8 , wherein the liquid or molten resin comprises caprolactam.

13. A method of forming a fully impregnated thermoplastic prepreg product comprising:
moving a fabric or mat from a starting point to an ending point, wherein the fabric or mat is subjected to a plurality of processes and wherein the fabric or mat is in substantially constant movement between the starting point and ending point;
drying the fabric or mat to remove residual moisture from the fabric or mat;
mixing a liquid or molten lactam with a catalyst and an activator via a mixing component to form a reactive resin mixture, the catalyst and activator facilitating in polymerizing the liquid or molten lactam to form a thermoplastic polymer;
applying the reactive resin mixture to the fabric or mat via a resin application die that is positioned above the fabric or mat so that the reactive resin mixture is applied to the fabric or mat as the fabric or mat is passed under the resin application die, the reactive resin mixture having a viscosity of 10 centipoises or less;
blowing, via a gas application mechanism, a moisture-free gas onto one or more surfaces of the fabric or mat, the gas application mechanism being positioned such that the moisture-free gas is blown onto the fabric or mat after application of the reactive resin mixture and prior to passing the fabric or mat through a curing oven, the moisture-free gas being blown onto the fabric or mat substantially prevent exposure of the reactive resin mixture to ambient moisture in a surrounding environment;
passing the fabric or mat through a calendar or press to press the reactive resin mixture entirely through the fabric or mat such that the reactive resin mixture fully saturates the fabric or mat; and
passing the fabric or mat through the curing oven to polymerize the reactive resin mixture and thereby form the thermoplastic polymer;
wherein the mixing component and the resin application die are heated to maintain a temperature of the liquid or molten lactam to between 70 and 120 degrees Celsius.

Assignees

• Johns Manville

Inventors

• Zhang Mingfu
• Gleich Klaus Friedrich
• Yohannes Asheber
• Block Michael John
• Asrar Jawed
• Bristol Derek Cooper
• Sandoval Christopher P

Classifications

• C08J3/247

  Heating methods · CPC title

• B29B15/122

  with a matrix in liquid form, e.g. as melt, solution or latex · CPC title

• C08K7/14

  Glass · CPC title

• Y10T442/2992

  Coated or impregnated glass fiber fabric · CPC title

• B05C9/14

  the auxiliary operation involving heating {or cooling} · CPC title