Method and manufacture, refurbishment, and repair of non-moldable polyurethane/polyurea conveyor belt covers and related products
View Patent ↗A method of applying a coating to a conveyor belt is provided. A first layer of adhesive is applied to a first surface of the conveyor belt and allowed to cure. One or more subsequent layers of adhesive are applied to the first layer of adhesive; a final layer of the one or more subsequent layers is allowed to become tacky. In some embodiments the adhesive is a two-part cement. In particular embodiments, the two-part cement includes an isocyanate part and a curable rubber part. A layer of two-part polyurethane/polyurea is applied to the tacky layer of adhesive. The coating process may be performed on conveyor belts having worn or damaged portions in an effort to repair the conveyor belts.
1. A method of applying a coating to a conveyor belt; the method comprising:
providing a conveyor belt;
applying a first layer of adhesive such that at least a portion of a first surface of the conveyor belt is coated with the first layer of adhesive;
permitting the first layer of adhesive to dry;
applying a second layer of adhesive to the conveyor belt, at least partially overlapping the first layer of adhesive;
permitting the second layer of adhesive to become tacky; and
applying a layer of two-part polyurethane/polyurea to the conveyor belt, at least partially overlapping the second layer of adhesive.
2. The method of claim 1 wherein:
said first layer of adhesive is comprised of a two-part cement.
3. The method of claim 2 wherein:
said two-part cement includes an isocyanate part and a curable rubber part.
4. The method of claim 2 wherein:
the first surface of said conveyor belt is comprised of rubber; and
said adhesive adheres and cross-links the first surface of the conveyor belt to bond the adhesive with the conveyor belt.
5. The method of claim 1 wherein:
the layer of two-part spray polyurethane/polyurea is applied in a manner producing a layer approximately ¼ to 5/16 of one inch in thickness.
6. The method of clam 1 further comprising:
the layer of two-part spray polyurethane/polyurea is applied in a manner producing a layer approximately 5/16 to ¾ of one inch in thickness.
7. The method of claim 1 wherein:
the layer of two-part polyurethane/polyurea has a durometer reading of between approximately 65 and 75 Shore A.
8. The method of claim 1 wherein:
the two-part polyurethane/polyurea comprises ORPC 70-HA.
9. The method of claim 1 wherein:
the layer of two-part polyurethane/polyurea has a durometer reading between approximately 60 and 80 Shore A.
10. The method of claim 1 wherein
the layer of two-part polyurethane/polyurea has a durometer reading of greater than 80 Shore A or less than 60 Shore A.
11. The method of claim 1 wherein:
a portion of the fist surface of said conveyor belt is worn or damaged; and
a portion of the worn or damaged portion of the first surface of said conveyor belt is removed prior to the step of applying the first layer of adhesive.
12. The method of claim 11 wherein:
the portion of the worn or damaged portion of the first surface of said conveyor belt is removed by grinding, buffing, or dissolving the worn or damaged portion.
13. The method of claim 1 wherein:
fist surface of said conveyor belt is comprised of a layer of two-part polyurethane/polyurea; said layer of two-part polyurethane/polyurea being worn or damaged; and
a portion of the worn or damaged layer of two-part polyurethane/polyurea is removed prior to the step of applying the first layer of adhesive.
14. The method of claim 13 wherein:
the portion of the worn or damaged layer of two-part polyurethane/polyurea is removed by grinding, buffing, or dissolving the worn or damaged portion.
15. A conveyor belt comprising:
a generally flexible support member;
a first layer of adhesive disposed on a first surface of the support member;
a second layer of adhesive disposed on the first layer of adhesive; and
a layer of two-part polyurethane/polyurea disposed on the second layer of adhesive.
16. The conveyor belt of claim 15 wherein:
the generally flexible support member is comprised of a length of fabric and a layer of rubber that is disposed on said length of fabric.
17. The conveyor belt of claim 16 wherein:
at least one of said first layer of adhesive and second layer of adhesive is comprised of a cement that includes an isocyanate part and a curable rubber part.
18. The conveyor belt of claim 17 wherein:
the layer of two-part polyurethane/polyurea is approximately ¼ to ¾ of one inch in thickness.
19. The conveyor belt of claim 17 wherein:
the layer of two-part polyurethane/polyurea has a durometer reading of between approximately 65 and 75 Shore A.
20. The conveyor belt of claim 19 wherein:
the layer of two-part polyurethane/polyurea comprises ORPC 70-HA.