Parison orientation cover for blowing / filling / sealing machine

Abstract

A gas distribution cover that is positionable over an open parison in a blowing / filling / sealing machine prior to container forming, filling and sealing that minimizes the likelihood that particles contaminate the open parison while conveying the open parison to a container forming, filling and sealing station.

Description

Technical Field

[0001] The present invention relates to blow / fill / seal technology and in particular to a protection device for extruded parisons in a blow / fill / seal machine. Background Art

[0002] Blow / Fill / Seal ("B / F / S") technology is the preferred technology for aseptic packaging of pharmaceutical and healthcare products. The packaging is a multi-step process of blow molding an extruded parison, forming a container, aseptically filling the formed container, and hermetically sealing the container in a single sequential operation in an automatic machine. The thermoplastic material is continuously hot extruded into a tubular shape between the mold parts, passing through a circular throat to form a hanging tube called a parison. When the extruded tube (parison) reaches the desired length, the mold is closed around the parison and the parison is cut from the extruder. The bottom portion of the parison is clamped closed, and the top is kept open and retained with a set of retaining jaws that are part of the mold assembly. The closed mold containing the parison is then transferred to the forming, filling and sealing station by the mold carriage.

[0003] The cutting of the parison typically involves the use of a heated moving cutter, such as a hot wire or hot knife that melts through and cuts the parison. A potential disadvantage associated with the use of a hot wire or similar expedient is the inherent risk of generating or producing parison particles or vapors during cutting and depositing the parison particles or vapors inside the final formed, filled and sealed container.

[0004] The present invention provides an apparatus and method that greatly reduces the likelihood of contaminating particles entering the severed parison portion during the blow / fill / seal process. Summary of the invention

[0005] The parison cover in a blow / fill / seal machine directs a protective gas envelope or curtain over the open end of the extruded parison and minimizes the potential for particle contamination during transfer to the filling and sealing process.

[0006] The parison cover is adapted to be attached to a blowing / filling / sealing machine between a parison extruder head and a filling station. The parison cover provides a protective environment for the extruded parison before forming, filling and sealing, and includes an elongated housing having a closed end and an open end. The housing defines a plenum chamber in the closed end portion of the housing and a gas distribution chamber separated from the plenum chamber by a perforated partition. A protective gas inlet for the plenum chamber is provided in the closed end portion of the housing, and a protective gas outlet is provided at the open end of the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the accompanying drawings,

[0008] Figure 1is a partial side elevational view of a B / F / S machine showing the location of a parison cover embodying the present invention in the B / F / S machine between the parison extruder head and an adjacent filling station;

[0009] Figure 2 is a side view of a parison cover embodying the present invention and mounted to a lid of a filling station;

[0010] Figure 3 yes Figure 2 An enlarged side view of a parison cover facing the parison extruder head;

[0011] Figure 4 yes Figure 2 and Figure 3 A side view of the parison cover shown in FIG.

[0012] Figure 5 yes Figure 2 An enlarged partial front view of a parison cover; and

[0013] Figure 6 It is along Figure 5 The plane 6-6 in the Figure 5 sectional view of . DETAILED DESCRIPTION

[0014] The present invention can be used in many different forms. The description and the drawings disclose only exemplary embodiments of the present invention. However, the present invention is not limited to the described embodiments.

[0015] Unless otherwise indicated, the exact shapes and sizes of the components depicted herein are not essential to the invention.

[0016] For ease of description, the apparatus and method of the present invention will be described in the normal (upright) operating position. Terms such as upper, lower, horizontal, etc. will be used with reference to this position. However, it will be understood that the apparatus of the present invention can be manufactured, stored, transported, used, and sold in orientations other than the described position.

[0017] The apparatus of the present invention may be used with the B / F / S machine disclosed in U.S. Pat. No. 4,707,966 to Weiler et al. The disclosure therein is incorporated herein by reference to the extent such disclosure is relevant and not inconsistent with this specification.

[0018] Reference Figure 1 , the parison cover 10 is shown located between the filling station 12 and the parison extruder head 14 of the B / F / S machine. Below the filling station 12 is shown a mold carrier 13, which carries the parison from the extruder head 14 to the filling station 12. The parison cover 10 is operably connected to a shielding gas supply hose 38 and will be discussed in more detail below.

[0019] Figure 2 The parison cover 10 is shown mounted to the filling station cover 16. Figure 2 In and still Figure 3-Figure 6 As seen in FIG. 1 , the parison cover 10 is an elongated shell 18 having a closed end 20 and an open end 22. Figure 5 and Figure 6 A perforated baffle 28, best shown in FIG. 1 , is disposed in the housing 18, spaced from the closed end 20, and together with the closed end portion of the housing defines the plenum 24. The perforated baffle 28 also serves as a back pressure generating device for the parison cover 10. During operation, the back pressure is typically in the range of about 10 to about 15 psi, and the shielding gas velocity exiting the parison cover at the open end is typically in the range of about 20 ft / sec to about 30 ft / sec.

[0020] The housing 18 defines a gas distribution chamber 30 downstream of the baffle 28 and terminates in a shielding gas outlet 36. Shielding gas, such as sterile air or sterile nitrogen, is supplied to the plenum 24 via a gas inlet 34 and a gas supply hose 38.

[0021] If desired, a particle monitor capable of detecting 0.5 micron particles may be provided below the shielding gas outlet 36 .

[0022] In the elongated housing 18, the front wall 19 and the rear wall 21 ( Figure 3 , Figure 4 and Figure 6 ) may be a solid plate. Alternatively, a portion of the front wall defining the gas distribution chamber 26 may be a hinged plate 30 held in place by a hinge 32, such as Figure 5 and Figure 6 A lock 40 in the side wall of the elongated housing 18 may be provided to secure the hinge plate 30 in a predetermined position relative to the shielding gas outlet. In this way, the speed of the shielding gas flow leaving the parison cover may be conveniently adjusted if desired.

[0023] The above description and drawings are illustrative embodiments of the present invention, but should not be considered as limiting. Other variations within the spirit and scope of the present invention are possible, and those skilled in the art will readily present these variations.

Claims

1. A parison cover adapted to be positioned in a blow / fill / seal machine in a gap between a parison extruder head and a filling station adjacent to the parison extruder head, the parison cover comprising: an elongated housing having a closed end and an open end; a perforated baffle in the housing, spaced from the closed end, defining a plenum chamber at the closed end portion of the housing and a shielding gas distribution chamber downstream of the baffle; A shielding gas inlet is defined in the closed end portion and a shielding gas outlet is defined at the open end.

2. The parison cover according to claim 1, wherein: The housing has an articulated swing plate which is located in a wall portion of the housing which defines the protective gas distribution chamber.

3. The preform cover according to claim 2 has a swing plate lock, which is mounted to the wall portion of the shell defining the gas distribution chamber, and the swing plate lock is operably associated with the swing plate to maintain the swing plate in a predetermined position relative to the protective gas outlet.

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