Patent Application
20140238977
Thermoplastic tapes can be used to bond to a substrate by heating the thermoplastic tape to melt the thermoplastic such that the thermoplastic fuses with the substrate. For example, thermoplastic tapes can be used to bond a pipe liner and a pipe jacket to form pipes that can be used to transport materials such as oil, gas, water and sewage. Typically, the heat required to melt the thermoplastic tape is supplied through convection, infrared or microwave heating.
According to an embodiment of the invention, a composite article for fusing to a substrate comprises a polymeric composite layer having a first polymeric matrix comprising at least one polymeric resin and an induction layer joined to the polymeric composite layer, wherein the induction layer has an induction-current susceptible material that generates heat when exposed to a magnetic field, wherein the induction layer is separate from the polymeric composite layer.
According to one embodiment, the first polymeric matrix includes a reinforcement material. In another embodiment, the induction-current susceptible material is a metal particulate.
In yet another embodiment, the induction layer includes a carrier matrix with at least one polymeric resin. The first polymeric matrix and the carrier matrix can comprise the same polymeric resin. The polymeric resin of the first polymeric matrix can be a polyethylene-based resin.
According to another embodiment of the invention, a method of forming a composite article for fusing to a substrate comprises providing a polymeric composite layer having a first polymeric matrix comprising at least one polymeric resin, providing an induction layer having an induction-current susceptible material that generates heat when exposed to a magnetic field, and joining the induction layer to the polymeric composite layer, wherein the induction layer is separate from the polymeric composite layer.
In another embodiment, the method further comprises forming the polymeric composite layer by combining a reinforcement material with a polymer resin. The reinforcement material can include glass fibers and the forming can include heating the glass fibers. The polymer resin can be applied to the reinforcement material by way of an extruder. The reinforcement material can include heated glass fibers and the forming can include moving the heated glass fibers and the applied polymer resin through heated pins to form a fully wet-out polymeric fiber composite.
In yet another embodiment, the joining step comprises applying at least one of heat, pressure or a combination of heat and pressure to the polymeric composite layer and the induction layer. In another embodiment, the joining step includes heating the polymeric composite layer and applying the heated polymeric composite layer to the induction layer to form a bond between the polymeric composite layer and the induction layer. In a still further embodiment, the joining step is combined with providing the induction layer step by heating and extruding a polymeric resin and the induction-current susceptible material onto the polymeric composite layer.
According to another embodiment, a method of joining a first polymeric material to a second polymeric material comprises providing a polymeric composite-induction tape formed of a polymeric composite layer having a first polymeric matrix with at least one polymeric resin, and a separate induction layer joined to the polymeric composite layer, wherein the induction layer has an induction-current susceptible material, placing at least one layer of the polymeric composite-induction tape between the first polymeric material and the second polymeric material with at least one of the polymeric composite layer or the induction layer in contact with the first polymeric material and the other of the polymeric composite layer or the induction layer in contact with the second polymeric material, and performing an induction cycle to melt at least one of the polymeric composite layer or induction layer to fuse the at least one of the polymeric composite layer or induction layer to the adjacent first polymeric material and the second polymeric material.
In another embodiment, the first polymeric material is a pipe jacket and the second polymeric material is a pipe liner. The placing step can include wrapping the at least one layer of polymeric composite-induction tape around the pipe liner. Further, more than one layer can be wrapped around the pipe liner and the performing step can be repeated for each layer.
In another embodiment, the placing at least one layer of polymeric composite-induction tape and the performing an induction cycle are repeated at least once to join the first polymeric material to the second polymeric material by at least two layers of polymeric composite-induction tape.
In the drawings:
The invention relates to a multi-layer composite article 10 comprising a polymeric composite layer 12 and an induction layer 14. According to an embodiment of the invention, the multi-layer composite article 10 can be used to provide a tape for use in wrapping pipes, such as pipes used in the gas and oil industry or used in the transport of water or sewage, for example. In one example, the multi-layer article 10 can be used for bonding a pipe jacket and pipe liner forming a pipe, such as a high pressure pipe used in the oil and gas industry.
The polymeric composite layer 12 can comprise a polymeric matrix which can include one or more thermoplastic resins. An example of a suitable thermoplastic resin includes polyethylene (PE), such as high density polyethylene (HDPE). The thermoplastic resin can be selected based on its compatibility with the substrate to which the polymeric resin layer 12 will be applied. The polymeric matrix can include reinforcement materials, such as glass, carbon, aramid or other natural or synthetic fibers known in the art. The polymeric composite layer 12 can be selected based on the desired properties of the layer and the intended use of the multi-layer article 10. For example, the polymeric composite layer 12 can be selected to be tough and have a high elongation to break length or suitable for use in cold weather or other weather extremes. Additional additives, such as colorants, preservatives, and fillers, for example, can be used in the polymeric composite layer 12, as is known in the art.
The induction layer 14 comprises a carrier matrix and an induction current-susceptible material. The carrier matrix can be made from a polymeric resin or combination of resins that is the same or different than the polymeric resin or combination of resins used in the polymeric composite layer 12. The carrier matrix can be selected based on compatibility with the polymeric composite layer 12 and is preferably capable of bonding with the polymeric composite layer 12. The induction current-susceptible material can be a particulate material, such as iron, iron alloy or other metal particulates, for example, which generate heat when exposed to a varying magnetic field. The carrier matrix and induction current-susceptible material can be selected based on the desired properties of the induction layer 14. For example, the carrier matrix can be selected to be tough and have a high elongation to break length or suitable for use in cold weather or other weather extremes.
FIGS. 2 and 3A-3C illustrate a flow chart of a method 100 for forming a multi-layer composite article 10 and a process 200 for forming a polymeric composite-induction tape 202 comprising the multi-layer article 10, respectively, in accordance with the embodiments of the invention. The sequence of steps depicted for any of the methods and processes described herein are for illustrative purposes only, and are not meant to limit the methods or processes in any way as it is understood that the steps may proceed in a different logical order, steps may be omitted, or additional or intervening steps may be included without detracting from the invention.
The method 100 includes providing a polymeric composite layer at 102 and an induction layer at 104. At 106 the polymeric composite layer and induction layer can be joined to form a multi-layer composite article at 108. The polymeric composite layer and induction layer provided at 102 and 104 can be joined at 106 by applying heat and/or pressure, which can include performing an induction cycle. It is also within the scope of the invention for any of the steps 102 through 106 to be repeated sequentially or simultaneously to provide a multi-layer article having more than two layers.
Referring now to
The polymer resin melt matrix 218 can comprise a polymer resin matrix, which may optionally include one or more additives, that has been heated in an extruder 222, for example, to melt the polymer resin matrix 218 for application to the glass fibers 208. The polymer resin melt matrix 218 and glass fibers 208 can be fed through moving heated pins at 224 to provide a polymeric composite layer 12 in the form of a polymeric composite tape layer 226. By moving the polymer resin melt matrix 218 and glass fibers 208 through the heated pins, the melted polymer resin surrounds and encapsulates the fibers to form what is sometimes referred to in the art as a fully wet-out polymeric fiber composite. The heated pins can have an adjustable arrangement and shape depending on the desired characteristics of the polymeric composite tape layer 226.
While the process 200 is discussed in the context of preparing a polymeric composite tape layer 226 having a polymer resin melt matrix 218 that includes glass fibers 208, it will be understood that the process 200 can be used in a similar manner with a variety of different fillers or combinations of fillers or that fillers can be excluded from the polymer resin melt matrix 218 without deviating from the scope of the invention. It is also within the scope of the invention for additional additives to be used in preparing the polymeric composite tape layer 226, such as colorants or preservatives, for example.
The polymeric composite tape layer 226 can be stored for later use or immediately used in forming the polymeric composite-induction tape 202. Referring now to
Referring now to
It will be understood that for both processes illustrated in
Referring now to
The pipe jacket 252 and pipe liner 254 can be made from any suitable polymeric material based on the intended use of the pipe 250. In one exemplary embodiment, the pipe jacket 252 and pipe liner 254 can be made from a PE-based resin, an example of which includes an HDPE resin, such as a bimodal 4710 HDPE resin, for example, based on its approval in the oil and gas industry for transportation of hydrocarbon gas and liquid. In this exemplary embodiment, the polymeric composite tape layer 226a-226c comprises from 55-75% by weight fiber glass reinforcements in a high melt flow HDPE resin matrix. The induction film 228a-228c comprises an HDPE resin carrier matrix with fine iron powder, such as 375 mesh, as the induction current-susceptible material. The iron powder can form about 30% of the volume of the induction film 228a-228c, although the amount may vary depending on the materials used in the polymeric composite-induction tape 202a-202c and pipe 250 and the intended use. The materials used to form the pipe jacket 252 and polymeric composite-induction tape 202a-202c can be selected based on their compatibility with each other and with the pipe liner 254, based on the desired characteristics and requirements in the intended field of use.
With reference to
Referring again to
As illustrated in
Referring now to
For example, in the field of oil and gas pipe lines, the pipe components are typically exposed to high pressures and are often expected to have an operation life span of 20 to 50 years. Providing the reinforcement material 208 in a separate layer from the induction current-susceptible particles 270 can reduce undesired interactions between the reinforcement material 208 and the induction current-susceptible particles 270 that could decrease the operation life span of the polymeric composite-induction tape 202 and components formed using the tape 202. The separate induction film layers 228 and polymeric composite tape layers 226 can expand and contract and fuse independently, which can contribute to the stability and the integrity of the polymeric composite-induction tape 202 during the operation life span of the pipe.
In addition, providing the induction-current susceptible particles 270 within the polymer resin melt matrix used to form the polymeric composite tape layer 226 can interfere with the impregnation process of the polymer resin melt matrix with the reinforcement material 208, as the induction-current susceptible particles 270 can abrade the reinforcement material 208 as well as increase the viscosity of the polymer resin melt matrix, which can slow or inhibit the impregnation process.
Furthermore, providing separate induction film layers 228 and polymeric composite tape layers 226 provides for opportunities to tailor each layer to provide the final product with the desired properties. For example, the induction film layer 228 can be provided as a tough, highly elastic polymer layer with a high elongation to break that can increase the impact resistance and the cold weather performance of the polymeric composite-induction tape 202. The polymeric composite tape layer 226 can be made from a resin with a higher viscosity than that of the resin used to form the induction film layer 228 to provide the polymeric composite tape layer 226 with different characteristics than that of the induction film layer 228.
In addition, because it is the induction film layer 228 that is providing the heat to melt the adjacent polymeric composite tape layer 226 on an adjacent polymeric-composite induction tape 202, it is not necessary to heat the polymeric composite tape layer 226 such that the entire polymeric composite tape layer 226 melts. It is sufficient to only melt a portion of the polymeric composite tape layer 226 such that a suitable degree of bonding between the polymeric composite tape layer 226 and the adjacent induction film layer 228 occurs. Heating the polymeric composite tape layer 226 to a degree such that the entire polymeric composite tape layer 226 melts can contribute to cycle fatigue of the layer.
In contrast to the present embodiments of the invention,
To the extent not already described, the different features and structures of the various embodiments may be used in combination with each other as desired. That one feature may not be illustrated in all of the embodiments is not meant to be construed that it cannot be, but is done for brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly disclosed.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing disclosure and drawings without departing from the spirit of the invention which is defined in the appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 61/768,120, filed Feb. 22, 2013, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61768120 | Feb 2013 | US |
