US20060081631A1

US20060081631A1 - Polymeric coated storage container

Info

Publication number: US20060081631A1
Application number: US11/252,911
Authority: US
Inventors: Vance Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-11-21
Filing date: 2005-10-18
Publication date: 2006-04-20
Also published as: US20050109783A1; WO2005051776A2; WO2005051776A3

Abstract

A container for transporting goods and materials includes a container body constructed of fiber or metal and a polymeric coating applied to the interior of the container body, the exterior thereof, or both such surfaces. The container may include a closure assembly adapted to secure a cover to the container body. A substrate suitable for use in the construction of containers for storing goods and materials includes a single fiber layer or multiple laminated and adhesively joined fiber layers forming a structure having a first side and a second side. The polymeric coating is bonded to the first side, the second side, or both sides to form the substrate. The fiber layer may be formed in the shape of various storage containers either before or after coating with the polymeric coating. A method for forming a substrate for use as a storage container is also disclosed.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent application Ser. No. 10/719,350 filed Nov. 21, 2003 entitled “Closure Assembly for a Storage Container”, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates generally to the field of storage containers and, more particularly, to fibrous storage containers, such as fiber drums.
2. Description of Related Art
Open-ended storage containers, such as conventional metal drums, are used in a variety of industries for the bulk transportation and storage of goods and materials. These drums are cylindrical in shape and have one closed end and one open end. Other versions have closed ends with a small opening in the top end for admitting and dispensing materials and liquids to and from the drum. Whether the drums are “open-head” or “closed-head” drums, they may be made of metal such as steel, fibrous material, or plastic.
Drums are often used to store liquids, semi-liquid materials such as adhesives, lubricants, hazardous materials, or other materials that contaminate or leave contaminants in the interior surface thereof. In the case of fiber drums, such drums are normally used once and then discarded once the interior becomes too contaminated with material for cleaning and re-use. Disposal and even recycling of such contaminated fiber drums also becomes problematic. One solution used in the bulk storage container industry and used for drums in particular whether made of metal, fiber, or other material, is to use a plastic slip liner or liner bag which is inserted into the drum and used to insulate the drum interior from the contained material. The plastic slip liner/bag may be discarded or recycled after the contents of the drum are removed. An example of a plastic slip liner intended generally for use in drums is disclosed in U.S. Pat. No. 6,630,529 to Robichaud. This patent discloses a thermoplastic material having specific additives for use as a drum slip liner and which provides increased resistance to fluid permeation.
Another solution aimed particularly for use in fiber-type drums is to apply or attach a liner layer to the interior of the fiber drum. One such example is disclosed in U.S. Pat. No. 5,137,206 to Hale which attempts to increase the usability of traditional fiber drums by coating the interior thereof with wax or silicone. However, such coatings are not structurally sound and will crack readily when the sidewall of the drum is impacted even lightly. A more common technique used in the bulk storage container industry is to adhesively apply a liner layer to the interior of the fiber drum. Typically, fiber drums are constructed of a plurality of fiber laminations that are glued together, with the liner layer attached adhesively to the inner-most fiber layer. The liner layer, depending upon the product to be contained in the fiber drum, may be plain kraft, foil, parchment (e.g., plain fiber), silicone, wax, etc. As an example, U.S. Pat. No. 5,465,863 to Seick et al. discloses a fiber drum having a wax or silicone layer secured to the interior of the drum via an adhesive. U.S. Pat. Nos. 5,285,086 and 5,137,206, both to Hale, similarly disclose a fiber drum having a plastic layer secured to the interior of the drum with an adhesive.
Adhesively lined fiber drums have improved resistance to liquid permeation and can be cleaned to some degree. However, such adhesively attached liners do not substantially improve the re-use and recyclability of fiber drums. This is due to the fact that, in the case of re-use, most shippers of bulk materials want a “clean” interior for their products and this typically entails the re-lining of the interior of the fiber drum. Accordingly, the previously-applied liner layer must typically be removed from the fiber drum interior and a new liner layer adhesively applied in its place. Thus, the recycling process requires the removal by cutting or other invasive means of the previous liner layer which often results in the tearing of the inner-most fiber lamination from the fiber drum body interior. This results in an unsightly appearance which is not preferred by bulk material shippers even when a “new” liner layer is applied over the underlying torn layer. Additionally, once the liner layer is removed it must be recycled separately from the fiber drum body. This makes the process of recycling the fiber drum very time consuming because the fiber drum body must be processed separately from the liner layer. Moreover, the use of adhesives increases the manufacturing time and cost associated with the original construction of the fiber drum, and the costs associated with refurbishing the fiber drum for re-use.
Another important design aspect of bulk storage containers, such as conventional open-head drums, is to ensure that the drum is capable of maintaining an adequate seal during use. Several government agencies, including the United States Department of Transportation, and other entities such as the United Nations, have promulgated regulations establishing certain tests that closed and open-head drums must pass in order to remain in commerce. All tests are conducted on randomly selected samples of drums supplied by original manufacturers and reconditioners of drums. The most important of these tests as well as the most difficult to pass particularly for open-head drums, whether formed of metal, fiber, or plastic, is what is known as a “drop test”. The procedure for a drop test requires the drum to befilled with either a fine powder or liquid and then sealed. The drum is dropped from various specified heights in various specified orientations onto a flat, smooth, and non-resilient surface. The drum must not rupture or leak in order to pass this test.
In general, open-head drums, whether formed of metal, fiber, or plastic are formed with a rounded rim at the open end, also referred to as a “chime”. U.S. Pat. No. 5,829,624 to Skolnik et al. discloses a known rounded “chime” design used on open-head metal drums. A circular cover or lid having a rounded edge and circumferential groove capable of accepting the rounded rim or chime is applied to close the drum. In most applications, a polymeric gasket is inserted into the groove and between the rounded chime and the rounded edge of the cover. A typical polymeric gasket known in the art is disclosed by U.S. Pat. No. 3,790,020 to Fine.
A typical closure assembly used in the bulk storage container industry to secure a lid or cover onto the chime of an open-head drum is comprised of a metal split ring having two opposing ends and an inward-facing groove or recess formed in the body of the split ring. The groove has a cross-section formed to accept the rounded chime of the drum body and the rounded edge of the cover. A locking device secures the cover onto the drum body. Typically, the locking device is a fastener combination, such as a bolt and nut, which is used to draw the ends of the split ring together and secures the connection between the cover and drum body. The split ring also deforms the gasket located between the cover and chime on the drum body providing a seal between the cover and drum body. Typical metal split rings known in the art are illustrated in U.S. Pat. No. 5,971,190 to Mannino; U.S. Pat. Nos. 6,435,576 and 4,982,864, both to Kusta; and U.S. Pat. Nos. 5,584,410 and 5,215,206, both to Siblik.
Generally, there is a need to provide a bulk storage container that has an expanded ability to transport liquid, semi-liquid, and solid materials. Additionally, there is a need to provide a bulk storage container that can eliminate the need for slip liners and other similar liners used to extend the usability and improve the recyclability of bulk storage containers.

SUMMARY OF THE INVENTION

Once aspect of the container disclosed herein is the use of an improved closure assembly for securing a lid or cover to the container. The container is typically open-ended and the closure assembly secures the lid or cover to the open-ended container. The container is comprised of an open-ended container body having a rim at the open end and a cover adapted to enclose the open end of the container body. The container further comprises a closure assembly for securing the cover to the container body. The closure assembly includes a coated split ring member cooperating with the cover and the rim of the container body and a locking device co-acting with the split ring member for securing the split ring member to the cover and the rim of the container body. The polymeric coating is typically applied to at least an inward-facing side of the split ring member. The split ring member has a cross-section configured to cooperate with the cover and the rim of the container body. The locking device co-acts with the split ring member to effect a seal between the cover and container body. The polymeric coating is applied to at least the inward-facing side of the split ring member, which contacts the cover and the rim of the container body.
The container may further include a gasket interposed between the cover and the rim of the container body. The container body, cover, and split ring member may each be made of metal, such as steel.
The split ring member may comprise two free ends, each having a lug connected thereto. The locking device generally comprises the lugs, a bolt, and typically a nut. The bolt extends through the lugs to draw the ends together and reduce the diameter of the split ring member for securing the split ring member to the cover and the rim of the container body. The lugs may comprise a threaded lug and an unthreaded lug. The bolt extends through the unthreaded lug and cooperates with the threaded lug to draw the ends of the split ring member together to reduce the diameter of the split ring member and secure the split ring member to the cover and the rim of the container body. The nut may be a jam nut cooperating with the bolt. The jam nut is usually located between the lugs.
The polymeric coating may comprise polyvinylchloride. The split ring member may have the polymeric coating applied onto the split ring member to substantially encapsulate the split ring member. The polymeric coating may be further applied to the cover and to the container body at least in the area of the rim of the container body and rounded edge of the cover.
The polymeric coating typically has a thickness of between about 15-30 mils on the split ring member. The polymeric coating may comprise a base layer applied directly on the surface of the split ring member and a top layer applied onto the base layer. The base layer typically comprises an epoxy-acrylic blend and the top layer typically comprises polyvinylchloride. The base layer may have a thickness of up to about 1 mil and the top layer may have a thickness of between about 15-25 mils on the base layer.
Another aspect disclosed herein relates to a method of manufacturing a closure assembly used to secure a cover or lid to an open-ended container having a rim. The method generally comprises the steps of providing a split ring member and applying a polymeric coating to at least an inward-facing side of the split ring member. The split ring member has a cross-section configured to cooperate with the cover and the rim of the container body. The polymeric coating is applied to at least the inward-facing side of the split ring member adapted to contact the cover and the rim of the container body. The step of applying the polymeric coating may comprise substantially encapsulating the split ring member with the polymeric coating.
The polymeric coating may comprise polyvinylchloride. The polymeric coating is typically applied to a thickness of between about 15-30 mils on the split ring member. The polymeric coating may comprise a base layer applied directly on the surface of the split ring member and a top layer applied onto the base layer. The base layer typically comprises an epoxy-acrylic blend and the top layer typically comprises polyvinylchloride. The base layer is more typically applied to a thickness of up to about 1 mil and the top layer is typically applied to a thickness between about 15-25 mils on the base layer.
The split ring member may be cleaned prior to applying the polymeric coating thereto. In particular, the method may include cleaning at least inward-facing side of the split ring member prior to applying the polymeric coating thereto. The cleaning step may comprise oxidizing and/or abrading the inward-facing side of the split ring member. The abrading step may include sand or shotblasting the inward-facing side of the split ring member.
Additionally, the entire surface of the split ring member may be cleaned and the polymeric coating applied to the split ring member to encase or enclose the split ring member. For example, the method may further comprise the steps of cleaning the surface of the split ring member and applying the polymeric coating to the cleaned surface of the split ring member. The cleaning step may comprise oxidizing the split ring member and/or abrading the surface of the split ring member.
In a further aspect, a container for bulk materials storage is disclosed which has an expanded ability to transport liquid, semi-liquid, and solid materials, and which can eliminate the need for slip liners and like liner layers previously used in the bulk storage container industry to extend the usability and improve the recyclability of such containers. The container may be formed of fibrous material and have an applied polymeric coating that may be easily cleaned through use of conventional cleansers and/or water. This applied coating makes the container suitable for storing liquid goods, semi-liquid goods, moisture-containing substances, hazardous materials or materials that would otherwise tend to contaminate the interior of a conventional fibrous container such as a fiber drum. The internally-coated container eliminates the need for plastic liners and like liner layers common in the prior art. Moreover, the “fiber” container disclosed herein remains light in weight while having enhanced structural strength and rigidity and extended reusability due to the applied polymeric coating.
Accordingly, in one embodiment, the container is adapted to transport goods and materials and comprises a container body having an inner surface and an outer surface, and a polymeric coating applied (e.g., bonded) to the inner surface, the outer surface, or both the inner surface and the outer surface. The container body may be constructed of steel or fiber. The polymeric coating may be a thermoset polymer including, but not limited to, polyurethane, polyurea, or epoxy. Alternatively, the polymeric coating may be a thermoplastic polymer, such as polyvinylchloride. The thickness of the polymeric coating is typically about or approximately 12 mils, however, any suitable thickness may be utilized. Additionally, the container may include an intermediate primer layer or a bonding (e.g., adhesive) layer for improving the adherence of the polymeric coating to the container body, typically when this coating is comprised of polyvinylchloride. The container body may assume various shapes including, but not limited to, substantially cylindrically shaped or polygonal shaped.
The container may be open-ended and comprise a rim adapted to receive a cover for enclosing the open end of the container body. The container may include a closure assembly adapted to secure the cover to the container body. The closure assembly may generally comprise: a) a split ring member cooperating with the cover and the rim of the container body, with the split ring member having a cross-section configured to cooperate with the cover and the rim of the container body; b) a locking device co-acting with the split ring member for securing the split ring member to the cover and the rim of the container body and effecting a seal between the cover and container body; and c) a polymeric coating applied to at least an inner surface of the split ring member that contacts the cover and the rim of the container body.
Another aspect of the invention relates to a substrate for use in construction of containers for storing goods and materials. The substrate generally comprises at least one fiber layer having a first side and a second side, and a polymeric coating applied (e.g., bonded) to the first side, the second side, or both the first side and the second side. The substrate may include an intermediate primer layer or a bonding layer for improving the adherence of the polymeric coating to the fiber layer, typically when this coating is comprised of polyvinylchloride.
In a further aspect, a method of forming a substrate for use as a storage container is disclosed. The method generally comprises providing at least one fiber layer having a first side and a second side, and applying a polymeric coating to the first side, the second side, or both the first side and the second side. The at least one fiber layer coated with polymeric coating may then be formed into the shape of a storage container. Alternatively, the fiber layer may be formed in the shape of a storage container prior to application of the polymeric coating onto the at least one fiber layer. The application of the polymeric material may be conducted by substantial uniform lamination, spraying, or brushing. A hydroxyl bond is typically formed between the polymeric coating and the fiber layer.
Further details and advantages of the present invention will become apparent from the following detailed description when read in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of an embodiment of a bulk storage and transport container incorporating a closure assembly;
FIG. 2 is a plan view of the closure assembly shown in FIG. 1;
FIG. 3 is an enlarged detail view of a locking device of the closure assembly shown in FIGS. 1 and 2;
FIG. 4 is a perspective view of a fastener used with the locking device of FIG. 3;
FIG. 5 is a cross-sectional view of a rim and sidewall portion of the storage container of FIG. 1;
FIG. 6 is a cross-sectional view of the rim and sidewall portion of the storage container of FIG. 1 according to another embodiment;
FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 1;
FIG. 8 is an exploded perspective view of another embodiment of the storage container shown in FIG. 1;
FIG. 9 is a partial cross-sectional and exploded view of the storage container of FIG. 8 taken along line 9-9 in FIG. 8, and further showing cross sectional details of a cover and the closure assembly of the storage container;
FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. 8;
FIG. 11 is a cross-sectional view of the storage container of FIG. 8 according to another embodiment;
FIG. 12 is a perspective of the storage container of the present invention formed as a shipping box;
FIG. 13 is a cross-sectional view taken along line 13-13 in FIG. 12; and
FIG. 14 is a cross-sectional view of a portion of a sidewall of the storage container of FIG. 8, wherein an intermediate primer layer or bonding layer is utilized.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-6, a storage container 10 (hereinafter “container 10”) according to an embodiment is generally shown. The container 10 may be open-ended as illustrated and comprised generally of a container body 12, a cover or lid 14 for enclosing the open-ended container body 12 and a closure assembly 16 for securing the cover or lid 14 to the container body 12. The container 10 is illustrated in the form of an open-head drum commonly used for storage and transportation of bulk materials, including liquids, and goods. Accordingly, the container body 12 is generally cylindrical in shape and the cover 14 has a corresponding circular shape to enclose the container body 12. The cover 14 is secured to the container body 12 by the closure assembly 16.
The container body 12 includes a top, open end 18. The top, open end 18 of the container body 12 defines a rim or “chime” 20 that is generally rounded in cross-section as shown, for example, in FIGS. 5 and 6. The container body 12 defines an opening 22 at the open end 18. The container body 12 may be formed of metal such as steel, plastic, a fibrous material such as fiber board, fiber backing, compressed cardboard, or multiple wound kraft paper. The container body 12 illustrated in FIGS. 1-6 is shown as a conventional open-head metal drum.
The lid or cover 14 is adapted to engage the top, open end 18 of the container body 12. More particularly, the cover 14 is adapted to seal against the rim or chime 20 at the open end 18 of the container body 12. As stated, the cover 14 is circular shaped to match the cylindrical shape of the container body 12. The cover 14 defines a rounded edge 24. The bottom side of the cover 14 is adapted to seal against the rim 20 of the container body 12 and defines a circumferential groove or recess 25 that receives the rim 20.
The container 10 further includes a sealing gasket 26 made of rubber or other polymeric material positioned between the cover 14 and the rim 20 of the container body 12. The gasket 26 provides a substantially fluid tight seal between the cover 14 and the rim 20 of the container body 12. The gasket 26 is disposed in the circumferential groove 25 defined in the cover 14, as is conventional in the art.
The closure assembly 16 includes a split ring member 28 configured to cooperate with the cover 14 and the rim 20 of the container body 12. The split ring member 28 defines a recess or groove 30 for receiving the rounded edge 24 of the cover 14 and the rim 20 of the container body 12. In particular, the recess or groove 30 is formed so that the split ring member 28 has a cross-section configured to cooperate with the rounded edge 24 of the cover 14 and the rim 20 of the container body 12. The split ring member 28 has two adjacent or opposing ends 32, 34 separated by a small opening or space 35. The split ring member 28 may be opened sufficiently to allow the split ring member 28 to be received about the cover 14 and the rim 20 of the container body 12. The split ring member 28 is typically made of metal, such as steel, and typically twelve (1.8 mm) gauge steel. Further, the split ring member 28 comprises a pair of lugs 36, 38 connected to the opposing ends 32, 34 of the split ring member 28, respectively. The lugs 36, 38 include a first lug 36 typically having an unthreaded opening or hole 40 and a second lug 38 typically having a threaded opening or hole 42. However, this configuration may be reversed.
The closure assembly 16 further comprises a locking device 50 co-acting with the split ring member 28 for securing the split ring member 28 to the cover 14 and the rim 20 of the container body 12 and to effect a seal between the cover 14 and the container body 12. Typically, the locking device 50 comprises the lugs 36, 38 connected to the opposing ends 32, 34 of the split ring member 28 and a conventional bolt 52 co-acting with the openings 40, 42 defined by the lugs 36, 38. In particular, the bolt 52 is inserted into the unthreaded opening 40 in the first lug 36 and is secured in the threaded opening 42 in the second lug 38. The bolt 52 includes a bolt head 54 and a threaded shaft 56.
To secure the cover 14 to the open end 18 of the container body 12 and enclose the top opening 22 in the container body 12, the split ring member 28 is placed around the cover 14 and rim 20 of the container body 12 and the bolt 52 is inserted through the unthreaded hole 40 in the first lug 36 and engages the threaded hole 42 in the second lug 38. The opposing ends 32, 34 of the split ring member 28 are drawn together to tighten the split ring member 28 around the cover 14 and the rim 20 of the container body 12. In this manner, the gasket 26 is compressed between the rounded edge 24 of the cover 14 and the rim 20 of the container body 12.
A well-known problem in the art is the spacing provided between the threaded shaft 56 of the bolt 52 and the unthreaded opening 40 in the first lug 36. This space allows undesired movement of the bolt 52 within the split ring member 28 when force is applied to the container 10, which allows movement of the split ring member 28. For example, if the container 10 is dropped or rolled, the space between the threaded shaft 56 of the bolt 52 and the unthreaded first lug 36 allows movement of the bolt 52 so that the lugs 36, 38 may become unaligned and the connection between the bolt 52 and the unthreaded first lug 36 is affected. To composite for this problem, a jam nut 58 is provided on the threaded shaft 56 between the lugs 36, 38. Thus, the bolt 52 is inserted through the unthreaded hole 40 and engages the threaded hole 42 to draw the opposing ends 32, 34 together. The jam nut 58 engages the threaded shaft 56 and secures the unthreaded first lug 36 between the head 54 of the bolt 52 and the jam nut 58. This configuration enables the closure assembly 16 to withstand impact forces without moving the bolt 52 within the space or opening 35 defined between the lugs 36, 38 and opposing ends 32, 34 of the split ring member 28.
A polymeric coating 60 may be applied to at least portions of the split ring member 28. In particular, as shown in FIG. 5, the polymeric coating 60 is applied at least to an inward-facing side or surface 62 of the split ring member 28 adapted to contact the cover 14 and the rim 20 of the container 10. Additionally, as shown in FIG. 6, the polymeric coating 60 may be applied to the entire surface of the split ring member 28 including the lugs 36, 38 so that the split ring member 28 is substantially encapsulated (e.g., enclosed) in the polymeric coating 60. Reference numeral 62 is used to represent the entire surface of the split ring member 28 in FIG. 6.
The polymeric coating 60 applied to the split ring member 28 improves the closure characteristics of the closure assembly 16 in comparison to typical traditional metal split ring closures known in the art. In particular, the polymeric coating 60 increases the frictional coefficient between areas of contact between the split ring member 28 and the rounded edge 24 of the cover 14 and rim 20 of the container body 12. This frictional interaction prevents the cover 14 from stripping-off the rim 20 of the container body 12 and through the split ring member 28 during drop tests. Additionally, the polymeric coating 60 has a degree of resiliency that accommodates and absorbs impact forces generated during drop tests. In summary, the polymeric coating 60 operates substantially as a resilient frictional film dampening impact forces during drop tests and increasing frictional interaction between the split ring member 28, cover 14, and rim 20 of the container body 12. As shown in FIGS. 1-6, the bottom, “closed” end of the container body 12 may be formed by a separate body panel or cover 68 that is welded to the bottom end of the container body 12.
The split ring member 28 is coated with the polymeric coating 60 according to the process described next. The split ring member 28 may be a “new” or “used” split ring member 28. In either case, the surface 62 of the split ring member 28 is cleaned to yield a near white metal condition. The cleaning step may include flame treatment, mechanical abrasion, and/or a chemical process. Typical mechanical abrasion techniques include sand or shotblasting. Once the surface 62 of the split ring member 28 has been cleaned, the polymeric coating 60 is applied. The polymeric coating 60 is typically comprised of two layers, a first or base layer 64 applied directly to the cleaned surface 62 of the split ring member 28 and a second or top layer 66 applied onto the base layer 64. The base layer 64 is typically an epoxy-acrylic blend. A suitable material for the base layer 64 is manufactured by The Thermoclad Company under the trademark Duravin®, in particular Duravin® AES-CJN (12% solids) vinyl polymer. The material for the top layer 66 is also manufactured by The Thermoclad Company under the trademark Duravin®, in particular Duravin® BDG-1V. The base layer 64 is applied as a thin coating of approximately 0.3-1 mil in thickness and the top layer 66 is applied to a thickness of between about 15-25 mils on the base layer 64. Overall, the polymer coating 60 has thickness of between about 15-30 mils on the surface 62 of the split ring member 28. The top layer 66 may be applied by conventional methods in the art such as fluidizing bed, flocking, or electrostatic deposition processes as long as the physical properties of the top layer 66 are not substantially altered. As indicated previously, the polymeric coating 60 may be applied to the entire exposed surface 62 of the split ring member 28 or only the side or surface 62 of the split ring member 28 that faces and contacts the cover 14 and the rim 20 of the container body 12.
Referring further to FIG. 7, an embodiment of the storage container 10 comprises a polymeric coating 80 typically applied to an inner surface or sidewall 82 of the container body 12, which is intended also to include the inward facing side of bottom cover 68. Accordingly, reference numeral 82 is intended to encompass the exposed interior surface area of container body 12 and this will be referred to hereinafter as “container interior 82”. Generally, a uniform application of the polymeric coating 80 prevents liquid and semi-liquid material, moisture-containing, hazardous, corrosive, or contaminating substances stored within the container 10 from corroding or otherwise fouling the metal forming the container body 12. In another embodiment described herein, the container body 12 is formed of fibrous material, and the polymeric material or coating 80 is provided within the container body 12 to generally prevent liquid and semi-liquid material, moisture-containing, hazardous, corrosive, or contaminating substances from permeating the fiber material comprising the container body 12. Additionally, the polymeric coating 80 allows the container 10 to be cleaned with water and/or liquid-based cleansers without risk of absorption by the fiber material comprising the container body 12, which would ordinarily damage or destroy a typical prior art fiber container. The polymeric coating 80 is also adapted withstand exposure to high temperature liquids or other substances without melting or deforming.
The polymeric coating 80 may be a thermoplastic or a thermoset polymer. Examples of thermoset polymers include, but are not limited to, polyurethane, polyurea, and epoxy. Other similar or suitable thermoset polymers may also be utilized as the polymeric coating 80. Presently, polyurea is the preferred thermoset polymer for polymeric coating 80. Alternatively, the polymeric coating 80 may be a thermoplastic polymer, such as polyvinylchloride or suitable equivalent. The polymeric coating 80 may be applied to the container interior 82 through various coating techniques including, but not limited to, lamination, liquid spraying, and brushing or suitably equivalent manual methods of applying polymeric coating 80.
The thickness of the application of the polymeric material and the thickness of the resultant polymeric coating 80 may vary depending on the implementation or storage requirements of the container 10. Thus, the coating thickness may be customized according to specific needs. Generally, the polymeric coating 80 is sufficiently thick to provide uniform coverage of the container interior 82. A desirable thickness of the polymeric coating 30 is approximately 12 mils. The typical minimum thickness of the polymeric coating 80 is at least about 5 mils. However, it is to be understood that any suitable thickness of the polymeric coating 80 may be utilized and that thickness thereof may be dependent upon application of the container 10. The polymeric coating 80 is typically clear and consistent throughout, but may be engineered into any number of colors, patterns or designs, prior to, during, or after application of the polymeric coating 80, as explained further herein.
FIGS. 8-10 depicts a fibrous storage container 10 a according to another embodiment. Fibrous storage container 10 a is shown in the form of a fiber drum. Accordingly, the container 10 a is preferably open-ended as illustrated and comprised generally of a container body 12 a, a cover or lid 14 a for enclosing the open-ended container body 12 a and a closure assembly 16 a for securing the cover or lid 14 a to the container body 12 a. The closure assembly 16 a may be provided with a polymer coating 60 according to the specific details presented previously in this disclosure, or may be uncoated as illustrated in FIG. 9. The container body 12 a is generally cylindrical in shape and the cover 14 a has a corresponding circular shape to enclose the container body 12 a. The cover 14 a is secured to the container body 12 a by the closure assembly 16 a. The cover 14 a, as shown in FIG. 9, is typically formed of metal such as steel but may also be formed of fibrous material if desired.
The container body 12 a includes a top, open end 18 a. The top, open end 18 a of the container body 12 a defines a rim or “chime” 20 a that is generally rounded in cross-section as shown, for example, in FIG. 9. As shown in FIG. 9, rim 20 a may be formed or reinforced by a metal rim member 90 that extends downward along the outside and inside of the sidewall of the container body 12 a. The container body 12 a defines an opening 22 a at the open end 18 a. The container body 12 a may be formed of fibrous material such as fiber board, fiber backing, compressed cardboard, or multiple wound kraft paper, and is typically comprised of multiple fibrous layers that are adhesively joined during a conventional lamination process.
The lid or cover 14 a is adapted to engage the top, open end 18 a of the container body 12 a. More particularly, the cover 14 a is adapted to seal against the rim or chime 20 a at the open end 18 a of the container body 12 a. The cover 14 a defines a receiving recess or groove 25 a adapted to receive the rim 20 a of the container body 12 a. The bottom end of the container body 20 a is enclosed by a bottom cover or base 68 a, typically formed of metal such as steel, that is secured to the bottom end of the container body 20 a with a metal band 92 or similar fastening structure. As shown in FIG. 10, the polymeric coating 80 a lines the container interior 82 a of the container body 12 a in generally the same manner as described in connection with FIGS. 1-7, to include bottom cover 68 a. It will be appreciated that bottom cover 68 a may also be formed on fibrous material as an alternative to metal such as steel. As shown in FIG. 9, the side of cover 14 a facing the container interior 82 a may also be coated with polymeric coating 80 a, including recess 25 a.
The fiber material defining container body 12 a may be laminated with polymeric material in liquid form causing a uniform and direct adhesion of the resultant polymeric coating 80 a to the fiber material. Specifically, applying the polymeric coating 80 in liquid form allows the polymeric material to penetrate between the fibers and bond to the overall fiber material as it hardens, and thereby chemically bonds with the fibers of the container interior 82 a, such as via a hydroxyl bond. Thus, no adhesive is necessary to secure the polymeric coating 80 a to the fiber material of the container body 12 a. A lamination coating process provides the most uniform application of the polymeric material, with the polymeric coating 80 a curing substantially on contact with the underlying fiber material. After application to the fiber material, the polymeric coating 80 a provides additional structural support, strength, reinforcement, and rigidity to the container body 12 a.
As shown in FIG. 14, if desired, an intermediate primer layer or bonding layer 94 may be utilized between the polymeric coating 80 a and the fiber material of the container body 12 a, typically when this coating is comprised of a thermoplastic polymer such as polyvinylchloride. The primer layer 94 may be necessary if the inner surface of the container body 12 a is too smooth, for example, to allow for adequate surface adhesion of the polyvinyl polymeric coating 80 a directly thereto. The primer layer or bonding layer 94 may be applied to any portion of the container body 12 a that is non-conducive to directly bonding with the polymeric coating 80 a, and may also be applied to the cover or lid 14 a on the side thereof facing the container interior 82 a. The primer layer may be of any suitable material that serves the functional purpose of a primer, such as an epoxy-acrylic blend (e.g., an adhesive), for example. If desired, a primer or bonding layer 94 may be used with metal container body 12 and polymeric coating 80 described previously in connection with FIGS. 1-7. The primer or bonding layer 94 may not be required when polymeric coating 80 is a thermoset polymer such as polyurea.
The polymeric coating 80 a is typically applied to the underlying fiber material substrate (e.g., fiberboard) prior to shaping thereof into a cylindrical form. However, it is to be understood that application of the polymeric coating 80 a may be performed after a non-polymeric coated container 10 a has been constructed. Therefore, even previously “used” fiber drums may be treated with the polymeric coating 80 a once having been thoroughly cleaned during cleaning operation. In such instances, the polymeric material forming polymeric coating 80 a is typically sprayed material directly onto the wall of the container interior 82 a once cleaned, even over top of a previously polymeric coating 80 a layer.
As shown in FIG. 11, the polymeric coating 80 a may also be applied to an outer surface 100 of the container body 12 a. Once applied to the outer surface 100, an adhesively applied label or wrapper 102 may be attached to the “outside” of container body 12 a. Such a label or wrapper 102 typically comprises an outer layer 104, which can contain design indicia, container content information, or simple advertisements, and an adhesive layer 106 for securing the outer layer 104 to the underlying polymeric coating 80 a layer. Furthermore, it will be appreciated that the “external” polymeric coating 80 a may also be applied to the bottom cover 68 a, if desired. Thus, it is to be understood that the application of the polymeric material forming polymeric coating 80 a is not limited to any specific side of the container body 12 a or any specific component of the container 10 a, and may be applied to conventional metal drums (both inside and out) as described previously.
It will be understood that the polymeric coating 80 may be applied to containers of various sizes and dimensions, including polygonal shaped containers. For example, FIG. 12 depicts an embodiment of container 10 b in the form of a box 110, having a polymeric coating 80 b applied to an interior portion thereof. The box 110 includes a plurality of walls 112 extending from a base 114, and lid closures 116. The walls 112 may be constructed of fibrous material including, but not limited to, fiberboard, fiber backing, or compressed cardboard. As shown in FIG. 12, the polymeric coating 80 b may be applied to interior portions of the box 110, however, it will be understood that the polymeric coating 80 b may also be applied to exterior portions of the box 110, including walls 112, base 104, and lid closures 116. The application of the polymeric coating 80 b may be similar to that discussed previously in this disclosure.
While the present invention has been described with reference to particular embodiments of a storage container and methods associated therewith, those skilled in the art may make modifications and alterations to the present invention without departing from the spirit and scope of the invention. Accordingly, the foregoing detailed description is intended to be illustrative rather than restrictive. The invention is defined by the appended claims, and all changes to the invention that fall within the meaning and the range of equivalency of the claims are embraced within their scope.

Claims

1. A container for transporting goods and materials, comprising:

a container body, wherein the container body includes an inner surface and an outer surface; and

a polymeric coating bonded to the inner surface, the outer surface, or both the inner surface and the outer surface.

2. The container of claim 1, wherein the polymeric coating is a thermoset polymer.

3. The container of claim 2, wherein the thermoset polymer is selected from the group consisting of polyurethane, polyurea, and epoxy.

4. The container of claim 1, wherein the polymeric coating is a thermoplastic polymer.

5. The container of claim 4, wherein the thermoplastic polymer is polyvinylchloride.

6. The container of claim 1, wherein the thickness of the polymeric coating is approximately 12 mils.

7. The container of claim 1, wherein the container body is polygonal shaped.

8. The container of claim 1, wherein the container body is substantially cylindrical-shaped.

9. The container of claim 1, wherein the container body is constructed of fiber.

10. The container of claim 9, wherein the polymeric coating forms a hydroxyl bond with the fiber of the container body.

11. The container of claim 1, wherein the container body is open-ended and comprises a rim, and wherein the rim is adapted to receive a cover for enclosing the open end of the container body.

12. The container of claim 11, further comprising a closure assembly adapted to secure the cover to the container body, the closure assembly comprising:

a split ring member cooperating with the cover and the rim of the container body, the split ring member having a cross-section configured to cooperate with the cover and the rim of the container body;

a locking device co-acting with the split ring member for securing the split ring member to the cover and the rim of the container body and effecting a seal between the cover and container body; and

a polymeric coating applied to at least an inner surface of the split ring member that contacts the cover and the rim of the container body.

13. A substrate for use in construction of containers for storing goods and materials, comprising:

at least one fiber layer comprising a first side and a second side; and

a polymeric coating bonded to the first side, the second side, or both the first side and the second side of the at least one fiber layer.

14. The substrate of claim 13, wherein the polymeric coating is a thermoset polymer or a thermoplastic polymer.

15. The substrate of claim 14, wherein the thermoset polymer is selected from the group consisting of polyurethane, polyurea, and epoxy.

16. The substrate of claim 14, wherein the thermoplastic polymer is polyvinylchloride.

17. The substrate of claim 13, wherein the polymeric coating forms a hydroxyl bond with the fiber layer.

18. A method of forming a substrate for use as a storage container, comprising the steps of:

a) providing at least one fiber layer comprising a first side and a second side; and

b) applying a polymeric coating to the first side, the second side, or both the first side and the second side of the at least one fiber layer.

c) allowing the polymeric layer to form a hydroxyl bond with the at least one fiber layer.

19. The method of claim 18, further comprising the step of:

d) forming the at least one fiber layer coated with the polymeric coating into the shape of a storage container.

20. The method of claim 18, wherein the at least fiber layer is formed in the shape of a storage container before the step of applying the polymeric coating is accomplished.