GB1580872A - Asphalt material package - Google Patents

Description

(54) ASPHALT MATERIAL PACKAGE (71) We, H.C. PRICE CO. a corporation duly organised under the laws of the State of California, United States of America, of: Price Tower, Bartlesville, Oklahoma, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a coating material package including a container housing corrosion protective coating material.

Corrosion protective coatings for pipes of all sizes and types are well known in the industry. In many instances the corrosion coating is applied in a coating yard and the coated pipe then shipped to the job site where the individual pipe sections or joints are welded together to form the continuous pipeline. To permit welding of the joints together, an area of several centimeters at each end of the pipe joint is left free of the corrosion coating. When two joints of pipe are welded together, an area at the weld joint of approximately one meter in length will be free of the corrosion coating.

It is thus necessary to apply a so-called field joint of coating material to this uncoated area.

For many years it was the practice in the industry to supply the components for the field joint coating material separately in relatively large packages or containers. The components were then mixed at the job site to prepare the field joint coating material. More recently, an effort has been made to supply the contractor with a premixed field joint coating material which need only be melted to a flowable liquid to prepare it for application at the job site. Such prepackaging was initially done in cardboard or similar containers which needed to be removed before the premixed coating material could be melted into a flowable liquid. Removal of the paper containers has been found to be a time consuming manual job and disposal of the containers is also likely to present problems, especially when pipe is being laid from an offshore lay barge.

An important aim of the invention is to provide a container which will have no deleterious effects on the coating material when amalgamated with it.

Another object of this invention is to provide a container for pipe coating material which when amalgamated into the material will enhance the physical properties of the coating.

According to one aspect of the present invention there is provided a coating material package comprising a rigid container housing an asphalt base corrosion protective pipe coating, said coating comprising 10% to 25% by weight asphalt and 75% to 90% by weight aggregate, said container presenting a rigid configuration comprising sidewalls and a bottom; said container comprising no more than 5% by weight of the coating material contained therein, said container being constructed from a material comprising at least one of the members of the group consisting of polyethylene, polypropylene and ethylenepropylene copolymer.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a top plan view of a container for coating according to the invention.

Figure 2 is a bottom plan view of the container shown in Figure 1; and Figure 3 is a horizontal, cross-sectional view taken along line 3-3 of Figure 2.

The coating material used for covering the weld joints of pipes coated with asphalt base corrosion coating may be within this range 10% to 25% by weight asphalt and 75% to 90% by weight aggregate. Any one of Grades I, II, or III asphalt (Asphalt Institute, specification series No. 7) is acceptable. The asphalt will have an operating temperature of no less than about 1200F and a softening point of no less than about 1500F. (Ring and ball ASTM standard testing procedure). The flash point of the asphalt is no less than about 4500 F. The preferred material is Grade II asphalt which has an operating temperature of 1500F and a softening point of 175 to 2000F.

The coating material is 75% to 90% aggregate which is preferably about a 50-50 mixture by weight, of sand and crushed limestone. The sand is preferably fine enough to pass 100two through a 6 mesh screen (U.S.A. Standard Testing Sieve). The crushed limestone is preferably fine enough for 100% to pass a 50 mesh screen and at least 75% by weight should pass a 200 mesh screen (both U.S.A. Standard Testing Sieve). Other equivalent materials may be used as the aggregate filler and it may be found desirable to incorporate small amounts of other materials to enhance the physical properties of the coating. For example, 0.1 to 0.15% by weight of glass fibre may be added for additional reinforcement and strength.

The sand and lime aggregate are directed to a batch mixing station where they are homogeneously dispersed throughout the asphalt which has been heated to a fluid state. When the coating material has been satisfactorily combined, a batch is deposited in individual containers 10, each of which is designed to hold about 50 pounds. The coating material will when added solidify in the containers and may then be easily transported to a pipe laying spread or lay barge for use by the pipeline contractor. By filling containers 10 to no more than about one inch from the top, the filled containers are easily and stably stacked one on top of the other. A number of containers may be stacked on a pallet in this manner for handling by conveyors and forklift equipment.The containers 10 are constructed from a material comprising one or more of the following: polyethylene, polypropylene or ethylenepropylene copolymer. The total weight of the container should not be more than 5% of the weight of the coating material contained thereby. A preferred formulation for the containers is 10% to 15% by weight polyethylene, 10% to 15% by weight ethylene-propylene copolymer and 70% to 80% by weight polypropylene. In the preferred form, each container 10 comprises substantially 1% to 2% of the weight of the coating material contained thereby.

Each container 10 is preferably injection moulded into a generally rectangular configuration including a bottom wall 12, sidewalls 14 and a circumscribing peripheral lip 16 extending outwardly from the uppermost terminal edge of the sidewalls. Sidewalls 14 are disposed at an acute angle relative to bottom wall 12, thereby presenting a slightly tapered configuration. From viewing Figure 2, it is seen that each of the corner sections 18 joining sidewalls 14 is rounded. A concave dimple 20 in bottom wall 12 facilitates removal of the moulded container from its mould.

The peripheral lip 16 which is of generally L-shaped cross-sectional configuration provides reinforcing for the sidewalls 14 and is supported throughout its length by spaced-apart generally planar web portions 22 which extend between the outer leg of the lip and the adjacent wall 14. It is to be noted that lip 16 is of uniform width along its length except for those portions which are adjacent corner sections 18. In the area of corners 18, the lip is slightly wider so as to compensate for the rounded corner and to present a uniform external dimension of the container. In addition to reinforcing the container, lip 16 serves as a convenient handhold for workers to lift the container. The tapered configuration of sidewalls 14 permits multiple containers to be stacked or "nested" one inside of the other, thereby greatly conserving the space required for shipping empty containers.

To this end, the lip 16 serves another function of permitting the containers to be easily separated when nested one within the other, particularly after long periods of time when the containers may have somewhat of a tendency to adhere to one another.

Other formulations satisfying the present specification for the containers may be utilized although the melt flow index of the polymers and/or copolymers selected should preferably be 3.5 to 5.0 (ASTM). Trace amounts of impurities, such as may be found in reclaimed plastics, generally will have no detrimental effect.

The containers 10 with the coating material contained therein are fed into a conventional chopper to reduce their size. In the interest of brevity, the chopper will not be described in detail, but suffice it to say that a device of the type commonly used to chop tree limbs may be employed. The size of the resulting particles of container and coating material is not critical, although the particles should be sufficiently small to readily melt in a short period of time.

Next, the chopped particles are directed to a melt kettle where they are mixed as the temperature is raised to melt the particles and present a flowable liquid A temperature of about 300"F to 400fits required to melt the container material into the asphalt. A temperature of about 375"F is preferable. It has been found that, when a plastics material such as polyethylene, polypropylene, or ethylenepropylene copolymer is attempted to be amalgamated into pure asphalt, it is not practical to achieve adequate melting and distribution of the plastics in any reasonable time, when operating at temperatures below 4000F. If the temperature is raised above 4000F, there is an ever present danger of reaching the flash point of the asphalt. With the present invention, however, it has been found that the plastics container material may be amalgamated in the asphalt base coating material following the procedure outlined above in a relatively short time. Generally, utilizing a mixing tank of 2 tons capacity, the mixing time should be no less than about 45 minutes. Under normal conditions, a maximum melt time is one hour. It is thought that the presence of the aggregate filler material in the asphalt has a shearing action on the plastics, and is the reason why the container material may be readily amal gamated into the asphalt.

It has also been found that the presence of the container material in the coating material modifies some of the physical properties of the final pipe coating. Below is a comparative analysis showing cured coating material without the container material present and with the presence of substantially 1.7% container material.

From the foregoing, it is apparent that the present invention provides for a substantially improved container for asphalt base pipe coating material and with an improved pipe coating resulting from amalgamation of the container into the coating material.

Reference is made to the Applicant's copending Application (Serial No. 1580871) No. 1747/78 which claims the above method of providing coating material for application to a surface.

WHAT WE CLAIM IS: 1. A coating material package comprising a rigid container housing an asphalt base corrosion protective pipe coating, said coating comprising 10% to 25% by weight asphalt and 75% to 90% by weight aggregate, said container presenting a rigid configuration comprising sidewalls and a bottom; said container comprising no more than 5% by weight of the coating material contained therein, said container being constructed from a material comprising at least one of the members of the group consisting of polyethylene, polypropylene and ethylene-prr pylene copolymer.

2. A package as t forth in claim 1 wherein said container material consists of 10% to 15% by weight polyethylene, 10% to 15% by weight propylene-ethylene copolymer and 70% to 80% by weight polypropylene.

3. A package as set forth in claim 2, wherein said container material is characterized by a melt flow index of from 3.5 to 5.0.

4. A coating material package comprising a container housing an asphalt base coating material, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. gamated into the asphalt. It has also been found that the presence of the container material in the coating material modifies some of the physical properties of the final pipe coating. Below is a comparative analysis showing cured coating material without the container material present and with the presence of substantially 1.7% container material. From the foregoing, it is apparent that the present invention provides for a substantially improved container for asphalt base pipe coating material and with an improved pipe coating resulting from amalgamation of the container into the coating material. Reference is made to the Applicant's copending Application (Serial No. 1580871) No. 1747/78 which claims the above method of providing coating material for application to a surface. WHAT WE CLAIM IS:

1. A coating material package comprising a rigid container housing an asphalt base corrosion protective pipe coating, said coating comprising 10% to 25% by weight asphalt and 75% to 90% by weight aggregate, said container presenting a rigid configuration comprising sidewalls and a bottom; said container comprising no more than 5% by weight of the coating material contained therein, said container being constructed from a material comprising at least one of the members of the group consisting of polyethylene, polypropylene and ethylene-prr pylene copolymer.

2. A package as t forth in claim 1 wherein said container material consists of 10% to 15% by weight polyethylene, 10% to 15% by weight propylene-ethylene copolymer and 70% to 80% by weight polypropylene.

3. A package as set forth in claim 2, wherein said container material is characterized by a melt flow index of from 3.5 to 5.0.

4. A coating material package comprising a container housing an asphalt base coating material, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.