U.S. patent application number 10/886437 was filed with the patent office on 2006-01-12 for blow-molded paintball and method of manufacture thereof.
Invention is credited to Glenn Forster.
Application Number | 20060005732 10/886437 |
Document ID | / |
Family ID | 35539973 |
Filed Date | 2006-01-12 |
United States Patent
Application |
20060005732 |
Kind Code |
A1 |
Forster; Glenn |
January 12, 2006 |
Blow-molded paintball and method of manufacture thereof
Abstract
Blow-fill-seal processing is employed to fabricate fully formed
and filled paintballs. A blow-fill-seal machine, known in the field
of medical container and syringe manufacture, is adapted for making
paintballs by employing spherical surface main molds which form
blow-molded shells and permit the shells to be filled with suitable
paintball dye and then sealing molds are used to seal the filled
paintball shell thereby resulting in a fully formed paintball
having an accurate spherical surface.
Inventors: |
Forster; Glenn; (Los
Angeles, CA) |
Correspondence
Address: |
LEONARD TACHNER, A PROFESSIONAL LAW;CORPORATION
17961 SKY PARK CIRCLE, SUITE 38-E
IRVINE
CA
92614
US
|
Family ID: |
35539973 |
Appl. No.: |
10/886437 |
Filed: |
July 6, 2004 |
Current U.S.
Class: |
102/502 |
Current CPC
Class: |
F42B 33/001 20130101;
F42B 12/40 20130101 |
Class at
Publication: |
102/502 |
International
Class: |
F42B 10/00 20060101
F42B010/00 |
Claims
1. A paintball comprising a blow-molded shell fabricated in a
blow-fill-seal process.
2. The paintball recited in claim 1 wherein said shell comprises a
biodegradable resin material.
3. The paintball recited in claim 1 wherein said blow-molded shell
is filled with a selected dye in said blow-fill-seal process.
4. A method for fabricating paintballs, the method comprising the
steps of: providing main mold halves having complimentary
hemispherical inner surfaces; extruding molten resin into said mold
halves in the form of a hollow tubular parison; joining said mold
halves to form a spherical interior; blowing a pressurized gas
through said parison to expand said resin to form a spherical shell
against the spherical interior of said mold halves; filling said
expanded resin shell with a suitable paintball dye; and sealing
said shell to form a completed paintball.
5. The method recited in claim 4 further comprising the step of
cutting said parison after said mold joining step.
6. The method recited in claim 4 further comprising the steps of
providing sealing mold halves adjacent said main mold halves and
selectively joining said sealing mold halves during said sealing
step.
7. The method recited in claim 4 further comprising the step of
separating said main mold halves to release said completed
paintball.
8. The method recited in claim 7 further comprising the step of
removing any flash that may have formed on said paintball shell.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to projectiles which are
typically fired from a CO.sub.2 or compressed air gas marker. More
specifically, the invention relates to a paintball projectile
structure formed by an outer blow-molded shell that fractures on
impact with a target and leaving a pigmented marking agent
contained within. This blow-molded paintball provides benefits not
found in traditional gelatin paintballs. The process used to make
the paintball is unique to paintball manufacturing and is a basis
of this invention.
[0003] 2. Background Art
[0004] Traditionally the shell of a gelatin paintball is formed
with a pair of hemispheres of gelatinous material similar to that
used to encase oral medicines such as cold capsules. As is the case
with oral medicines, these gelatin shell paint balls are soluble in
water. Upon striking the target, a paintball fractures to mark the
target with coloring agent contained within the paintball shell.
These gelatinous paintballs have the following negative attributes:
Because the gelatin shell is soluble in water, the gelatin is
easily affected by temperature and humidity conditions. The
paintballs must be stored in almost perfect conditions to insure
quality. Gelatin paintballs are also subject to irregular shelf
life because of temperature and humidity conditions. These factors
affect the performance of the paintball in many ways. First, the
paintball becomes out of round and thus does not fly straight.
Second, an out of round paintball is more likely to cause jamming
problems within the paintball marker firing the paintball. Third,
paintballs exposed to excessive humidity and/or heat, are less
likely to break open and mark the target on impact. Fourth,
paintballs exposed to cold or not enough humidity become brittle
and are more likely to break inside the marker in the process of
firing the paintballs. Fifth, gelatin paintballs, when made are
left with a seam that cannot be removed and further contributes to
the inaccuracy of the gelatin shell paintball when fired. Finally,
the manufacturing process for gelatin paintballs must include a
lengthy period within a special dehumidifying room to allow the
paintballs to cure before they are ready for use. This extra step
is not only expensive, but also very unpredictable.
[0005] U.S. Pat. Nos. 5,254,379 and 5,639,526 to Katsiopoulos et al
disclose paintballs fabricated using a plastic shell. Although the
preferred fabrication method is described as injection molding two
hemisphere-shaped shell portions that are joined along a common
seam, there is also reference to possible use of blow molding to
form the shell. However, there is no suggestion of a blow-fill-seal
process. Ordinary blow molding of a paintball shell would produce
an empty thin shell with an aperture. Separate filling of the shell
and sealing the aperture would be time consuming, labor intensive
and subject the fragile empty shell to handling which could reduce
yield and affect roundness.
SUMMARY OF THE INVENTION
[0006] The manufacturing process of the present invention may be
referred to as Blow-Fill-Seal technology. Blow-Fill-Seal technology
has already been in use for many years, usually to make products in
the medical industry. In the present invention this technology is
uniquely adapted to make paintballs.
[0007] As mentioned above, traditional gelatin paintballs come with
many drawbacks. None of these drawbacks are found in paintballs
formed using Blow-Fill-Seal technology. The material used to make
the paintball shell may be biodegradable resin that is not
susceptible to temperature and humidity changes. This is a benefit
that allows longer shelf life and allows consumers to use the
product in extreme cold, heat and humidity conditions without
affecting the performance of the product. The paintball itself is
formed with a much more spherical nature/characteristic thus
allowing the paintball to fly farther and much more accurately when
fired from a CO.sub.2 or compressed air marker. The manufacturing
process is simplified and shortened compared to manufacture of
traditional gelatin paintballs. There is no longer a need for
dehumidifying rooms to let the paintball cure after manufacturing.
Paintballs formed using Blow-Fill-Seal technology are completely
finished as they leave the machine. The harness/breakability of the
paintball is also easily controlled in the manufacturing process by
adjusting the amount of resin used to make the outer paintball
shell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The aforementioned objects and advantages of the present
invention, as well as additional objects and advantages thereof,
will be more fully understood hereinafter as a result of a detailed
description of a preferred embodiment when taken in conjunction
with the following drawings in which:
[0009] FIG. 1 illustrates the open paintball molds receiving a
parison from an extruder head;
[0010] FIG. 2 illustrates the closed paintball molds and the
parison being cut;
[0011] FIG. 3 illustrates the closed molds at the filling station
after the molten parison has formed a paintball ball shell; and
[0012] FIG. 4 illustrates the fully molded, filled and sealed
paintball after the sealing molds have sealed the remaining
aperture.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0013] Blow-fill-seal technology, originally developed in Europe in
the 1930's and introduced in the United States in the 1960's, has
emerged as a preferred method for aseptic packaging of
pharmaceutical and healthcare products due to unrivaled flexibility
in container design, overall product quality, product output and
low operational costs. The multi-step process of blow molding,
aseptic filling and hermetic sealing of liquid products may be
achieved in one sequential operation on a compact, automated
machine frame with fill volumes ranging from 0.1 milliliter (ml) to
1,000 ml.
[0014] A variety of polymers may be used in the process, low and
high-density polyethylene and polypropylene being the most popular.
The innate ability to form the container/closure during the actual
aseptic packaging process allows for custom design of the product
to meet the specific needs of the application.
[0015] Recent advancements in machine design allow for insertion of
pre-molded, pre-sterilized components to be molded into a container
creating additional design options to create multi-use product
containers. Furthermore, the blow-fill-seal process flow is
normally impacted by only two raw materials, product and polymer,
that are each processed inline, thereby making the process amenable
to large uninterrupted batch sizes, some in excess of 500,000
units, and fill durations of up to 120 hours. The net effect is
routinely an increase in production efficiency and a subsequent
decrease in operational costs for the user.
[0016] The blow-fill-seal process is a robust, advanced aseptic
processing technology, recognized by worldwide regulatory
authorities for its inherent operational advantages over
conventional aseptic production. Blow-fill-seal systems offer a
unique combination of flexibility in packaging design, low
operating cost and a high degree of sterility assurance. The
machines require a minimum number of operating personnel and have a
relatively small space requirement.
[0017] The blow-fill-seal manufacturing process practiced by the
blow-fill-seal machines known to the prior art is generally
considered to be a preferred process for manufacturing pre-filled
plastic syringes. In such blow-fill-seal manufacturing process, a
semi-molten, hollow, cylindrical plastic parison is extruded
downwardly between cavities provided in a pair of open and opposed
main molds and open and opposed pair of gripping jaws mounted for
reciprocal movement toward and away from each other; the mold
cavities are shaped complementarity to the pre-filled plastic
container to be formed. The gripping jaws grip the upper portion of
the parison and the main molds are then closed around the lower
portion of the plastic parison to seal the bottom of the container
after which a cutting knife severs the upper portion of the parison
to separate it from the extruder. Pressurized air is then injected
into the severed lower parison portion to force lower portions of
the parison outwardly against the walls of the main mold cavities
to partially form the container but leaving the partially formed
product open at the top for subsequent liquid filling. Thereafter,
a liquid fill nozzle is advanced above, or slightly into, and is
injected or dispensed into the partially formed plastic container
after which the filling nozzle is withdrawn and the sealing molds
are closed to seal the upper portion of the parison and complete
the forming or molding of the pre-filled plastic container.
Blow-Fill Seal Process
[0018] Shell Molding
[0019] Thermoplastic is continuously extruded in a tubular shape.
When the tube reaches the correct length, the mold closes and the
parison is cut. The bottom of the parison is pinched closed and the
top is held in place with a set of holding jaws. The mold is then
transferred to a position under the filling station.
[0020] Shell Filling
[0021] The nozzle assembly lowers into the parison until the
nozzles form a seal with the neck of the mold. Shell formation may
be completed by applying a vacuum on the mold-side of the shell and
blowing sterile filtered air or other gas into the interior of the
shell. An electronic fill system delivers a precise amount of dye
into the shell. The nozzles then retract into their original
position.
[0022] Shell Sealing
[0023] Following completion of the filling process, the top of the
shell remains semi-molten. Separate seal molds close to form the
top and hermetically seal the shell. The molds open and the
paintball is then conveyed out of the machine.
[0024] The method of the present invention may be carried out in a
variety of blow-fill-seal machines currently employed to
manufacture containers for pharmaceuticals and syringes. They key
change is to employ mold halves having a spherical interior shape
to form a paintball shell and seal mold halves to seal the shell
after it=s filled, but without corrupting its spherical surface.
The accompanying figures are used to generically explain the
blow-fill-seal process for paintballs, it being understood that
there are numerous variations that may be made depending upon
machine implementation.
[0025] As seen in FIGS. 1 to 4, a typical blow-fill-seal apparatus
10 that may be used to fabricate paintballs, comprises main mold
halves 12 and 14 and seal mold halves 16 and 18. Apparatus 10 also
comprises parison grippers 20 and 22, cutter 24 and extruder head
26.
[0026] As shown in FIG. 1, initially the main mold halves 12 and 14
are separated and positioned beneath extruder head 26 to permit the
head to extend a parison 28 of molten resin between the interior
surfaces of the halves. After the parison 28 reaches the lower ends
of the halves, the halves are moved into mutual engagement to form
a full spherical interior 15 trapping a tubular segment of the
parison therein. FIG. 2 illustrates the action of the parison
grippers 20 and 22 which limit the flow of resin from head 26 when
they come in contact with the bulbous formation of the resin above
the mold. Cutter 24 then slices through the enlarged portion of the
parison 28 thereby permitting a station change as shown in FIG.
3.
[0027] FIG. 3 shows the mold positioned beneath an inflating and
filling tube 35. Tube 35 employs a pressurized gas (i.e., air,
nitrogen) to expand the mold resin parison against the spherical
interior 15 of the main mold halves 12 and 14, thereby forming a
spherical paintball shell 30. In some blow-fill-seal machines, the
main mold halves may have small vacuum channels in their walls 25
to assist in expanding the parison to form the shell. Tube 35 then
fills the shell 30 with the desired fill commonly employed in
conventional paintballs. The contents 32 are injected through an
unsealed shell aperture 29 shown in FIG. 3.
[0028] After the shell is filled, the sealing mold halves 18 and 16
are then actuated as shown in FIG. 4. The aperture 29 is sealed
closed, thereby leaving a fully formed spherical shell filled with
dye. A flash 34 may be formed at the lower end of the main mold
halves 12 and 14. After the completed formation, filling and
sealing of the paintball, the molds are separated and the flash 34
is removed using conventional flash removal techniques.
[0029] It will be understood that although FIGS. 14 illustrate
blow-fill-seal fabrication of a unitary paintball, a typical
process employed in the present invention would produce numerous
paintballs in each cycle simultaneously so that economy of mass
production can be realized in a high volume process.
[0030] Having thus disclosed an exemplary embodiment of the method
of the present invention, it will be understood that there may be
various modifications and additions in an actual blow-fill-seal
machine employed to carry out the steps described herein for the
production of paintballs. Accordingly, the scope hereof is to be
limited only by the appended claims and their equivalents.
* * * * *