Liners for high temperature materials
Provided are liners suitable for use in a bulk container. The liners can hold high temperature materials (e.g., materials reaching temperatures greater than 120° C.) and can comprise at least one ply including polyethylene. The liners can exhibit high dart impact and can provide a balance of stiffness, toughness, and seal strength. The at least one ply of the liner according to embodiments disclosed herein comprises a first layer, a tie layer, and a second layer, wherein the tie layer is disposed between the first layer and the second layer. In further embodiments, the at least one ply of the liner can include a second tie layer and a third layer, wherein the second tie layer is disposed between the first layer and the third layer.
1 . A liner suitable for use in a bulk container, the liner comprising:
at least one sidewall comprising at least one ply, the at least one ply comprising:
a first layer comprising at least 70 wt. %, based on total weight of the first layer, of a polyethylene;
a tie layer comprising at least 60 wt. %, based on total weight of the tie layer, of a propylene-based elastomer having a density in the range of from 0.850 g/cc to 0.900 g/cc and a melt flow rate of from 1 to 8 g/10 min; and
a second layer having a melting point of greater than 140° C. and comprising at least 50 wt. %, based on total weight of the second layer, of a homopolypropylene having a density of from 0.890 to 0.910 g/cc and melt flow rate of from 1 to 5 g/10 min; and
wherein the tie layer is disposed between the first layer and the second layer; and
wherein the at least one ply has a Dart Impact Type A of greater than 5 g/μm and wherein the second layer forms an interior surface of the liner.
2 . The liner of claim 1 , wherein the at least one ply further comprises:
a second tie layer comprising at least 60 wt. %, based on the total weight of the second tie layer, of a second propylene-based elastomer having a density in the range of from 0.850 g/cc to 0.900 g/cc and a melt flow rate of 1 to 8 g/10 mins; and
a third layer having a melting point greater than 140° C. and comprising at least 50 wt. %, based on the total weight of the third layer, of a second polypropylene having a density of from 0.890 to 0.910 g/cc and melt flow rate of from 1 to 5 g/10 min;
wherein the second tie layer is disposed between the first layer and the third layer.
3 . The liner of claim 1 , wherein the first layer comprises greater than 30 wt. % of the at least one ply.
4 . The liner of claim 1 , wherein the polyethylene of the first layer has a density of less than 0.920 g/cc and melt index (I 2 ) of less than 2.0 g/10 min.
5 . The liner of claim 1 , wherein the at least one ply has a plateau seal strength of greater than 35 N/25 mm.
6 . The liner of claim 1 , wherein the at least one ply has a 2% secant modulus of greater than 250 MPa in the machine or transverse direction.