Conveyor belt
This invention relates to a conveyor belt comprising a composition comprising a) a (co)polyester A comprising hard segments comprising a polyester and having a melting temperature T mA of between 200° C. and 240° C. as measured according to ISO 11357-1/-3 (10° C./min), wherein the (co)polyester A is present in an amount of between 1 and 60 wt % with respect to the total weight of the composition; and b) a copolyester B comprising hard segments comprising a polyester wherein the (co)polyester B has a melting temperature T mB of between 100° C. and 180° C., as measured according to ISO 11357-1/-3 (10° C./min), wherein the copolyester B is present in an amount of between 40 and 99 wt % with respect to the total weight of the composition. The invention also relates to a process for preparing the conveyor belt.
1 . A conveyor belt which is formed of a polyester composition comprising a blend of:
a) between 1 and 60 wt % with respect to the total weight of the composition of a (co)polyester A comprising hard segments comprising a polyester, wherein the (co)polyester A has a melting temperature T mA of between 200° C. and 240° C. as measured according to ISO 11357-1/-3 (10° C./min); and
b) between 40 and 99 wt % with respect to the total weight of the composition of a copolyester B comprising hard segments comprising a polyester, wherein the copolyester B has a melting temperature T mB of between 100° C. and 180° C., as measured according to ISO 11357-1/-3 (10° C./min), wherein
the polyester composition contains no glass fibers or nucleating agents such that the conveyor belt formed of the polyester composition exhibits less warpage as compared to a conveyor belt formed of a polyester composition in which the copolyester B is replaced by the (co) polyester A.
2 . The conveyor belt according to claim 1 , wherein the polyester composition has a bimodal melting behavior exhibiting at least two peaks, wherein one peak P1 is between 200° C. and 240° C. and another peak P2 is between 100° C. and 180° C.
3 . The conveyor belt according to claim 2 , wherein T mA -T mB is at least 40° C. and/or P1-P2 is at least 40° C.
4 . The conveyor belt according to claim 1 , wherein the hard segments of the (co) polyester A and/or the copolyester B comprise polybutylene terephthalate (PBT).
5 . The conveyor belt according to claim 1 , wherein the copolyester B comprises soft segments selected from the group consisting of aliphatic polyesters, aliphatic polyethers, dimer fatty acids, dimer fatty diols and combinations thereof.
6 . The conveyor belt according to claim 1 , wherein copolyester B further comprises polybutylene isophthalate (PBI) segments in an amount of between 5 and 50 wt % with respect to the total amount of copolyester B.
7 . The conveyor belt according to claim 1 , wherein the polyester composition further comprises at least one additive selected from the group consisting of stabilizers, colorants and combinations thereof.
8 . The conveyor belt according to claim 1 , wherein the (co) polyester A is polybutylene terephthalate (PBT).
9 . The conveyor belt according to claim 1 , wherein the conveyor belt is an extruded conveyor belt.
10 . The conveyor belt according to claim 2 , wherein T mA -T mB is at least 50° C. and/or P1-P2 is at least 50° C.
11 . The conveyor belt according to claim 2 , wherein T mA -T mB is at least 60° C. and/or P1-P2 is at least 60° C.
12 . The conveyor belt according to claim 1 , wherein the copolyester B comprises soft segments of an aliphatic polyether.
13 . The conveyor belt according to claim 12 , wherein the aliphatic polyether is polytetramethylene oxide (PTMO).
14 . A process for preparing the conveyor belt according to claim 1 , comprising at least the following steps:
a) providing the polyester composition comprising the blend of the (co) polyester A and the copolyester B;
b) bringing the polyester composition to a temperature of between 230° C. and 290° C. to form a melt;
c) extruding the melt through a die;
d) cooling the extruded melt to form the conveyor belt; and
e) optionally welding parts onto the conveyor belt.
15 . The process according to claim 14 , wherein T mA -T mB is at least 40° C.
16 . The process according to claim 14 , wherein T mA -T mB is at least 50° C.
17 . The process according to claim 14 , wherein T mA -T mB is at least 60° C.
18 . The process according to claim 14 , wherein the copolyester B further comprises soft segments selected from the group consisting of aliphatic polyesters, aliphatic polyethers, aliphatic polycarbonates, dimer fatty acids, dimer fatty diols and combinations thereof.
19 . The process according to claim 14 , wherein step a) comprises providing the polyester composition as a dry blend by mixing the (co) polyester A and the copolyester B.
20 . The process according to claim 14 , wherein the process further comprises subjecting the (co) polyester A and/or the copolyester B to a drying step before bringing the (co) polyester A and the copolyester B to a temperature of between 230° C. and 290° C. to form a melt according to step b).
21 . A process for transporting food, comprising at least the following steps:
(i) providing the conveyor belt according to claim 1 ;
(ii) providing food on the conveyor belt; and
(iii) moving the conveyor belt with the food thereon in a desired direction.