Abuse resistant preform and container neck finish

Abstract

A neck finish of a preform or container having a crystallized top sealing surface (TSS) for withstanding deformation from multiple use cycles. In a returnable and fillable container, the improved TSS has enhanced caustic stress crack resistance resulting in a more secure finish-closure seal and an extended container life (number of refill cycles).

1 . A neck finish of a preform or container for receiving a closure and adapted to withstand the abuse of multiple use cycles without leakage failure, the neck finish having a thread, bead or snap-on mechanism for attaching the closure, and an open upper end with a top sealing surface (TSS) which forms a liquid tight seal with the closure, wherein the TSS is crystallized. 
   
   
       2 . The neck finish of  claim 1 , for a pressurized returnable and refillable container. 
   
   
       3 . The neck finish of  claim 2 , wherein the container can withstand at least ten (10) refill cycles, including a hot caustic wash at a temperature of at least 60° C. and pressured filling of at least 3 atmospheres, while maintaining a secure seal with the closure. 
   
   
       4 . The neck finish of  claim 2 , wherein the container can withstand at least twenty (20) refill cycles, including a hot caustic wash at a temperature of at least 60° C. and pressured filling of at least 3 atmospheres, while maintaining a secure seal with the closure. 
   
   
       5 . The neck finish of  claim 2 , wherein the container can withstand at least twenty five (25) refill cycles, including a hot caustic wash at a temperature of at least 60° C. and pressured filling of at least 3 atmospheres, while maintaining a secure seal with the closure. 
   
   
       6 . The neck finish of  claim 2 , wherein the crystallized portion of the neck finish extends from the TSS downwardly and terminates above the thread, bead or snap-on mechanism. 
   
   
       7 . The neck finish of  claim 2 , wherein the neck finish is made of a crystallizable polymer selected from the group consisting of polyesters, polyolefins, and polyamides. 
   
   
       8 . The neck finish of  claim 2 , wherein the neck finish comprises polyethylene terephthalate homopolymer or copolymers. 
   
   
       9 . The neck finish of  claim 2 , wherein the neck finish is injection molded. 
   
   
       10 . The neck finish of  claim 2 , wherein the crystallized TSS is opaque and the remainder of the neck finish is substantially transparent. 
   
   
       11 . The neck finish of  claim 10 , wherein the refillable container is substantially transparent below the opaque TSS. 
   
   
       12 . The neck finish of a container of  claim 10  including a closure having a sealing fin for engaging the TSS. 
   
   
       13 . The neck finish of a container of  claim 10  including a closure having a sealing liner for engaging the TSS. 
   
   
       14 . A container comprising:
 a pressurized returnable and refillable container being cold filled with a carbonated beverage, and able to withstand at least 10 refill cycles including a hot caustic wash at a temperature of at least 60° C. and pressurized filling of at least 3 atmospheres;   the container having a neck finish made of a substantially transparent, amorphous and unoriented crystallizable polymer, and a crystallized opaque top sealing surface (TSS).   
   
   
       15 . The container of  claim 14 , including a closure which forms a liquid tight seal with the TSS. 
   
   
       16 . The container of  claim 15 , wherein the polymer comprises polyethylene terephthalate homopolymer or copolymers. 
   
   
       17 . The container of  claim 16 , wherein the container is able to withstand at least 20 refill cycles. 
   
   
       18 . The container of  claim 17 , wherein the container is able to withstand at least 25 refill cycles. 
   
   
       19 . A method of making a neck finish of a preform or container for withstanding the abuse of multiple use cycles, the method comprising providing a neck finish having a thread, bead or snap-on mechanism for attaching a closure, and above the attaching mechanism a top sealing surface (TSS) for forming a liquid tight seal with the closure, the method including crystallizing the TSS. 
   
   
       20 . The method of  claim 19 , wherein the neck finish comprises a substantially transparent, amorphous and unoriented crystallizable polymer and the TSS is heated to crystallize and render the TSS opaque. 
   
   
       21 . The method of  claim 20 , wherein the neck finish is for a pressurized returnable and refillable container.