Method of forming an overmolded vial

Abstract

A method of forming a vial, preferably for use in a level, is disclosed. The method comprises providing a cylinder formed from a first material having an inner surface defining a cavity and an outer surface, molding a second material around and onto the outer surface to form an overmolded body, and machining the inner surface of the body formed to arrive at a cavity having a desired shape. A bubble can then be positioned in the cavity by partially filling it with a liquid. In certain embodiments, the method includes positioning at least one marker ring or indicia on the outer surface prior to the molding step so that the ring/indicia is enclosed between the cylinder and second material. The marker ring or the indicia so positioned will preferably not penetrate the inner surface so that movement of the bubble within the cavity is unimpeded. In another aspect, the method includes providing a molded body of a first material having a sidewall that extends between an inner surface defining a cavity and an outer surface, the sidewall being sufficiently thin to have been molded to form the cavity to have a desired shape, and molding a second material around and onto the outer surface of the body such that it reinforces the sidewall against breakage.

1 . A method of forming a vial comprising: 
 providing a cylinder formed from a first material, the cylinder having a sidewall with an inner surface defining a cavity and an outer surface;    molding a second material around and onto the outer surface to form an overmolded body;    machining the inner surface of the body to form a cavity having a desired shape.    
   
   
       2 . The method of  claim 1  wherein the first and second materials are the same acrylic material having a melting point and wherein the cylinder is solid and is maintained at a temperature less than the melting point while the second material is molded around the cylinder.  
   
   
       3 . The method of  claim 1  wherein the first material is polycarbonate and the second material is acrylic.  
   
   
       4 . The method of  claim 1  wherein the second material is molded around and onto the outer surface of the cylinder by: 
 positioning the cylinder on a core pin;    inserting the core pin into a mold;    injecting the second material into the mold; and    ejecting the overmolded body from the mold.    
   
   
       5 . The method of  claim 4  wherein the first and second materials are the same acrylic material having a melting point and wherein the cylinder is solid and is cooled by the core pin to be maintained at a temperature less than the melting point during the molding step.  
   
   
       6 . The method of  claim 1  further comprising positioning at least one marker ring on the outer surface of the cylinder such that the second material is molded around the marker ring and the marker ring is enclosed between the cylinder and the second material.  
   
   
       7 . The method of  claim 6  wherein the cylinder is molded and the marker ring is embedded into the outer surface such that the marker ring does not extend through the inner surface.  
   
   
       8 . The method of  claim 6  wherein the marker ring is hot stamped onto the outer surface.  
   
   
       9 . The method of  claim 6  wherein the second material is molded around and onto the cylinder and marker ring by: 
 positioning the cylinder and marker ring on a core pin;    inserting the core pin into a mold;    injecting the second material into the mold; and    ejecting the overmolded body from the mold.    
   
   
       10 . The method of  claim 6  wherein the cavity has a maximum diameter and the at least one marker ring is two marker rings such that the maximum diameter is positioned equidistant between the marker rings.  
   
   
       11 . The method of  claim 1  further comprising positioning a bubble in the cavity by partially filling the cavity with a liquid and enclosing the cavity with an end closure.  
   
   
       12 . The method of  claim 1  wherein the cavity has a length and a longitudinal cross-section of the desired shape is curvilinear along the length.  
   
   
       13 . The method of  claim 12  wherein the desired shape is barrel-shaped.  
   
   
       14 . The method of  claim 1  further comprising positioning indicia on the outer surface of the cylinder before the molding step.  
   
   
       15 . The method of  claim 14  wherein the indicia is hot stamped onto the cylinder.  
   
   
       16 . A method of forming a vial comprising: 
 providing a cylinder formed from a first material, the cylinder having a sidewall with an inner surface defining a cavity and an outer surface;    molding a sleeve formed from a second material around and onto the outer surface;    positioning indicia on the outer surface, the inner surface not being penetrated by the indicia and the indicia being bounded by the cylinder and the sleeve.    
   
   
       17 . The method of  claim 16  wherein the first and second materials are acrylic.  
   
   
       18 . The method of  claim 16  wherein the cylinder and the sleeve extend from a first end to a second end and further comprising partially filling the cavity with a liquid to define a bubble, the cavity being sized to receive a first end closure at the first end and a second end closure at the second end.  
   
   
       19 . The method of  claim 16  wherein the indicia is at least one marker ring.  
   
   
       20 . The method of  claim 16  further comprising machining the inner surface of the overmolded cylinder to form a cavity having a desired shape.  
   
   
       21 . A method of forming a vial comprising: 
 providing a molded body of a first material having a sidewall extending between an inner surface defining a cavity and an outer surface, the sidewall being sufficiently thin to have been molded to form the cavity to have a desired shape; and    molding a second material around and onto the outer surface of the body to reinforce the sidewall against breakage.    
   
   
       22 . The method of  claim 21  wherein the desired shape forms a barrel-shaped cavity.  
   
   
       23 . The method of  claim 21  wherein the body is a cylinder.  
   
   
       24 . The method of  claim 21  further comprising embedding at least one marker ring into the outer surface, the marker ring not extending through the inner surface and the second material being molded around and onto the marker ring such that the marker ring is enclosed between the first material and the second material.