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2019-10-29
15/947,191
2018-04-06
US 10,457,602 B1
2019-10-29
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Wenwen Cai
Hancock Hughey LLP
2038-04-26
Smart Summary: New asphalt formulations use recycled materials to create roofing products like shingles and roll membranes that meet industry performance standards. These formulations reduce issues like blistering and are more resistant to damage from scuffing and granule loss compared to traditional asphalt. The recycled materials include types of plastics, such as polyethylene and polypropylene, sourced from items like agricultural films and consumer bags. There is a growing demand for improved asphalt roofing products, especially as single-ply options become more popular due to their easier installation and lower costs. The challenge lies in balancing the cost and desired properties, such as elasticity and rigidity, when creating these asphalt compositions. 🚀 TL;DR
The asphalt formulations according to the invention include the use of post-consumer recycled materials and provide for shingle and roll roofing membranes that exhibit performance requirements of the roofing industry. The formulations provide additional benefits of less blistering compared to conventional polymer modified asphaltic formulations, and are less susceptible to external damage such as scuffing and granule loss. The post-consumer recycled materials are olefinic polymers such as polyethylene and polypropylene waxes that may be derived from, for example, feedstock from waste agricultural films, bottles, milk jugs, waste plastics, consumer bags, polyolefin plastics, and synthesized plastics.
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C04B26/26 » CPC main
Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete; Macromolecular compounds Bituminous materials, e.g. tar, pitch
C04B16/04 » CPC further
Use of organic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of organic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone Macromolecular compounds
C04B18/20 » CPC further
Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone ; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Waste materials; Refuse organic from macromolecular compounds
C04B18/22 » CPC further
Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone ; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Waste materials; Refuse organic from macromolecular compounds Rubber, e.g. ground waste tires
C04B2111/00586 » CPC further
Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use; Uses not provided for elsewhere in Roofing materials
The present invention relates broadly to roofing products, and more specifically to asphalt compositions and processes for manufacturing the asphaltic compositions, and to products into which the compositions are incorporated.
The market for bituminous roofing product has decreased in recent years due in part to the increased use of single ply roll roofing products such as thermoplastic polyolefin (TPO) and polyvinyl chloride (PVC) for low-sloped roofing. Compared to asphalt roll roofing, single ply products are easier to apply and therefore have lower labor costs for installation. These reduced costs have increased the popularity of single ply. Nonetheless, there is a continuous need for asphalt roll roofing and therefore a continuous call for improvements to asphalt formulations that provide for better performance characteristics.
Asphalt shingles continue to be the largest selling steep slope product, but there is a continuous call for improvement in asphalt shingles, incorporating properties that will lead to better weather resistance, whether that is hail, wind or cold. Asphalt shingles are traditionally made with air-oxidized asphalt, usually having a softening point between 195° F. and 225° F., with a penetration between 10 and 25. Use of a polymer modified asphalt imparts properties that resist hail, perform better in high winds events and can function better in all temperatures.
When formulating asphalt compositions for use in roofing products, there is a trade off when selecting the components used in a given blend. For example, some commonly used components enhance elasticity, while other additives can be used to improve rigidity where that characteristic is desired. More specifically, radial and linear styrene butadiene styrene (rSBS and LSBS) are elastomers that are often used in asphalt formulations. Both tend to improve the elasticity of the final product but are fairly expensive. Polyethylene and polypropylene plastomers and other polyolefins are also used in asphalt and they tend to increase rigidity of the final product and pricing may be less expensive. Formulating an asphalt composition can be a difficult endeavor when faced with the competing costs and functional characteristics that may be desired for the finished product.
Another consideration that is important in all aspects of commercial asphalt production is to formulate the blend in a manner that reduces the carbon footprint of the product. This can be a difficult challenge considering that bitumen forms the major component of asphalt formulations, and the finished materials must perform for many years. Using recycled materials in the asphalt formulations requires balancing of properties, compatibility and pricing.
The present invention comprises bituminous compositions and methods of manufacturing them, and bituminous roll roofing and shingle products in which the bituminous compositions are used. The asphalt roll products described herein may be applied in the various manners, including heat or torch application, cold-process, self-adhering or hot mopped.
The asphalt formulations according to the invention provide for membranes that exhibit less blistering compared to conventional formulations, impact resistance and other benefits including less susceptibility to external damage such as from scuffing.
Advantageously, embodiments of the asphaltic formulations of the present invention incorporate olefin polymers comprising polyethylene and/or polypropylene waxes that are derived from recycled content.
In one aspect, the present invention relates to formulation that utilizes recycled content with virgin polymers to help improve the properties of the asphalt.
In another aspect, the present invention uses recycled materials to provide a partial replacement of asphalt, with or without virgin polymers to improve and strengthen the asphalt.
In still another aspect, the mixing process is defined using time, temperature and mix process, where the recycled polymers mixed with the asphalt form a strong matrix where the recycled materials are dispersed, but not dissolved, giving the properties described herein, yielding desired strength, elasticity and hardness.
In still other aspects, bio-based asphalt consisting in part or whole of recycled materials may be used as a partial replacement of the asphalt and a compatibilizer with the other recycled materials.
In all aspects, properties of formulas yield viscosities allowing the polymer modified materials to be run similar to air-oxidized coatings in normal roofing plant manufacturing equipment.
The invention will now be described in detail with reference to several formulations and processing methods according to the invention.
Various embodiments and formulations set forth herein call for inclusion of recycled polyethylene and/or recycled polypropylene. Suitable recycled polyethylene and/or recycled polypropylene for use in accordance with the invention are commercially available from a variety of commercial sources. It will further be appreciated by those of skill in the art that in the formulations and embodiments disclosed herein the components incorporated into the formulations is provided by percentages. The percentages that are disclosed should in all instances be considered as ranges and that the functional properties that the components provide to the finished product produced by any embodiment may be substantially reproduced with deviations in the percentages listed below. Without limitation, therefore, the percentages provided herein of components should be considered as including variances in the listed percentages, subject to the desired characteristics of the finished product. Moreover, the percentages and ranges of a component of one formulation may be combined with components from another formulation to generate derivations in formulations.
| Formulation No. 1: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 3% | Between |
| about 2-8% | ||
| radial styrene butadiene styrene | 5% | Between |
| (“rSBS” herein) | about 3-7% | |
| linear styrene butadiene styrene | 2% | Between |
| (“LSBS” herein) | about 1-7% | |
| Recycled Oxidized/non oxidized | 3.5% | Between |
| polyethylene | about 1-5% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 2: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 5% | Between |
| about 4-6% | ||
| radial styrene butadiene | 2% | Between |
| styrene (“rSBS”) | about 1-6% | |
| linear styrene butadiene styrene | 3% | Between |
| (“LSBS”) | about 2-6% | |
| Recycled Oxidized/non oxidized | 2% | Between |
| polyethylene | about 1-5% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 3: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 5% | Between |
| about 4-8% | ||
| rSBS | 2% | Between |
| about 1-6% | ||
| LSBS | 3% | Between |
| about 2-6% | ||
| recycled polyethylene/ | Between | |
| polypropylene | 3% | about 2-5% |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
The following formulations are specifically for use with engineered coatings, for example, with roofing shingles:
| Formulation No. 4: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10 - 80 mesh | 10% | Between |
| about 8-12% | ||
| rSBS | 1% | Between about |
| 0.5-1.5% | ||
| LSBS | 2% | Between |
| about 1-3% | ||
| recycled polyethylene/ | 3% | Between |
| polypropylene | about 1-5% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 5: |
| Embodiment | Range | |
| Compound | Percentage | Percentage |
| ground tire rubber, 10-80 mesh | 10% | Between |
| about 8-12% | ||
| rSBS | 1% | Between |
| about 0.5-5% | ||
| LSBS | 3% | Between |
| about 1-5% | ||
| recycled polyethylene/ | 3.5% | Between |
| polypropylene | about 2-5% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 6: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 10% | Between |
| about 8-12% | ||
| rSBS | 1% | Between |
| about 0.5-5% | ||
| LSBS | 3% | Between |
| about 1-5% | ||
| recycled polyethylene/ | 3% | Between |
| polypropylene | about 2-5% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 7: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 10% | Between |
| about 8-12% | ||
| rSBS | 1% | Between |
| about 0.5-5% | ||
| LSBS | 3% | Between |
| about 2-5% | ||
| Recycled polyethylene | 2% | Between |
| Recycled Sources: Feedstock from | about 1-5% | |
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 8: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 6% | Between |
| about 4-8% | ||
| rSBS | 4% | Between |
| about 3-7% | ||
| maleated propylene or recycled | 2% | Between |
| polyethylene/polypropylene | about 1-7% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 9: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 6% | Between |
| about 4-8% | ||
| rSBS | 4% | Between |
| about 3-7% | ||
| recycled polyethylene/ | 2.5% | Between |
| polypropylene | about 2-7% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 10: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 6% | Between |
| about 4-8% | ||
| rSBS | 3% | Between |
| about 2-4% | ||
| LSBS | 1% | Between about |
| 0.5-2.5% | ||
| recycled polyethylene/ | 2.5% | Between |
| polypropylene | about 1-4% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 11: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| rSBS | 3% | Between |
| about 1-6% | ||
| LSBS | 2% | Between |
| about 1-6% | ||
| recycled polyethylene/ | 3% | Between |
| polypropylene | about 2-5% | |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, | ||
| milk jugs, waste plastics, | ||
| consumer bags, polyolefin | ||
| plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 12: |
| Embodi- | ||
| ment Per- | ||
| Compound | centage | Percentage Range |
| ground tire rubber, 10-80 mesh | 10% | Between about 8-12% |
| styrene ethylene butadiene styrene | 5% | Between about 3-7% |
| (“SEBS”) | ||
| Maleated propylene/polyethylene or | 4% | Between about 2-6% |
| recycled polyethylene/polypropylene | ||
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
SP: 273 Pen 77;
23 Visc 375-1343
Amplitude Sweep, Ramp logarithmic 6 pts per decade 0.1% to 100% strain level, 10 Rads at 194 F.
Net Yield=G′/G″. 2.5%-4%γ, 2000-5000 PA. 8 mm plates, 1 mm gap.
| Formulation No. 13: |
| Embodi- | ||
| ment Per- | Percentage | |
| Compound | centage | Range |
| bio-asphalt | 10% | Between about 8-12% |
| rSBS | 5% | Between about 1-7% |
| LSBS | 2% | Between about 1-7% |
| Maleated propylene/polyethylene or | 3% | Between about 2-5% |
| recycled polyethylene/polypropylene | ||
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 14: |
| Embodi- | ||
| ment Per- | Percentage | |
| Compound | centage | Range |
| bio-asphalt | 15% | Between about |
| 12-18% | ||
| thermal fluid/recycled oil | 1% | Between about |
| 0.5-2% | ||
| rSBS | 5% | Between about 1-6% |
| LSBS | 2% | Between about 1-6% |
| Maleated propylene/polyethylene or | 3% | Between about 2-5% |
| recycled polyethylene/polypropylene | ||
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 15: |
| Embodi- | ||
| ment Per- | Percentage | |
| Compound | centage | Range |
| bio-asphalt | 15% | Between about |
| 12-18% | ||
| ground tire rubber, 10-80 mesh | 17% | Between about |
| 15-20% | ||
| LSBS | 3% | Between about 2-5% |
| Maleated propylene/polyethylene or | 3% | Between about 2-5% |
| recycled polyethylene/polypropylene | ||
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 16: |
| Embodi- | ||
| ment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10 - 80 mesh | 5% | Between about 4-6% |
| rSBS | 3% | Between about 1-6% |
| LSBS | 3% | Between about 1-6% |
| recycled polyethylene/polypropylene | 2% | Between about 1-5% |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
Each of the formulations above in nos. 1 through 16 was processed in a batch according to the following methodology. Preferred equipment is a rotor-stator high shear mill (mixer), such as a Siefer or Supratron mill, for the initial mix, although other types of high shear mixers, including in-line mixers will yield similar results but with potentially longer mix times. Mix time will be dependent upon the temperature, as well as the gap on the mill, or the amount of shear generated. Slow speed agitation with high temperatures do not produce the desired batch properties.
The following formulations are specifically for use with engineered coatings, for example, with roll materials:
| Formulation No. 17: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 10% | Between about 8-12% |
| rSBS | 3% | Between about 1-6% |
| LSBS | 3% | Between about 1-6% |
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 18: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 10% | Between about 8-12% |
| rSBS | 4% | Between about 1-8% |
| LSBS | 4% | Between about 1-8% |
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 19: |
| Embodi- | ||
| ment Per- | ||
| Compound | centage | Percentage Range |
| ground tire rubber, 10-80 mesh | 15% | Between about |
| 12-18% | ||
| rSBS | 3% | Between about 2-5% |
| maleated propylene/polyethylene or | 2% | Between about 1-5% |
| recycled polyethylene/polypropylene | ||
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 20: |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 15% | Between about 12-18% |
| rSBS | 1% | Between about 0.5-14% |
| LSBS | 2% | Between about 1-4% |
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 21: |
| Embodi- | ||
| ment Per- | Percentage | |
| Compound | centage | Range |
| ground tire rubber, 10-80 mesh | 15% | Between about |
| 13-17% | ||
| bio-asphalt | 10% | Between about |
| 8-12% | ||
| Recycled oil | 2% | Between about 1-3% |
| LSBS | 3% | Between about 1-6% |
| maleated propylene/polyethylene or | 4% | Between about 2-5% |
| recycled polyethylene/polypropylene | ||
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formulation No. 22: |
| Embodi- | ||
| ment Per- | Percentage | |
| Compound | centage | Range |
| ground tire rubber, 10-80 mesh | 17% | Between about |
| 15-20% | ||
| Bio-asphalt | 20% | Between about |
| 18-22% | ||
| LSBS | 3% | Between about 2-4% |
| maleated propylene/polyethylene or | 4% | Between about 3-5% |
| recycled polyethylene/polypropylene | ||
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
Each of the formulations above in formulations nos. 17 through 22 was processed in a batch according to the following methodology. Preferred equipment is a rotor-stator high shear mill (mixer), such as a Siefer or Supratron mill, for the initial mix, although other types of high shear mixers, including in-line mixers will yield similar results but with potentially longer mix times. Mix time will be dependent upon the temperature, as well as the gap on the mill, or the amount of shear generated. Slow speed agitation with high temperatures do not produce the desired batch properties.
| Formulation No. 23: |
| Embodi- | ||
| ment Per- | Percentage | |
| Compound | centage | Range |
| ground tire rubber, 10-80 mesh | 10% | Between about |
| 8-12% | ||
| rSBS | 1% | Between about |
| 0.5-3% | ||
| LSBS | 2% | Between about 1-3% |
| recycled polyethylene/polypropylene | 3% | Between about 2-4% |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
The formulation of formulation no. 23 was processed in a batch according to the following methodology. Preferred equipment is a rotor-stator high shear mill (mixer), such as a Siefer or Supratron mill, for the initial mix, although other types of high shear mixers, including in-line mixers will yield similar results but with potentially longer mix times. Mix time will be dependent upon the temperature, as well as the gap on the mill, or the amount of shear generated. Slow speed agitation with high temperatures do not produce the desired batch properties.
| Formulation No. 24: |
| High Temperature |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 10% | Between about 8-12% |
| rSBS | 3% | Between about 1-6% |
| LSBS | 3% | Between about 1-6% |
| Tack oil | 4% | Between about 2-5% |
| Naphthenic Oils/Paraffinic | ||
| Oils/Refined Oils | ||
| asphalt, 20-220 pen | balance | |
| Formulation No. 25: |
| Top Formula |
| Embodi- | ||
| ment Per- | Percentage | |
| Compound | centage | Range |
| ground tire rubber, 10-80 mesh | 15% | Between about |
| 13-18% | ||
| rSBS | 1% | Between about |
| 0.5-1.5% | ||
| LSBS | 2% | Between about 1-3% |
| recycled polyethylene/polypropylene | 3% | Between about 2-4% |
| Recycled Sources: Feedstock from | ||
| waste agricultural films, bottles, milk | ||
| jugs, waste plastics, consumer bags, | ||
| polyolefin plastics, synthesized plastics. | ||
| Asphalt, 20 to 220 penetration | balance | |
| Formula 26 Bottom Coat |
| Embodiment | Percentage | |
| Compound | Percentage | Range |
| ground tire rubber, 10-80 mesh | 10% | Between about 8-12% |
| rSBS | 1% | Between about 0.5-5% |
| LSBS | 4% | Between about 1-5% |
| tack oil | 4% | Between about 2-5% |
| Naphthenic Oils/Paraffinic | ||
| Oils/Refined Oils | ||
| asphalt, 20-220 pen | balance | |
The formulation above in no. 24-26 was processed in a batch according to the following methodology. Again, the preferred equipment is a rotor-stator high shear mill (mixer), such as a Siefer or Supratron mill, for the initial mix, although other types of high shear mixers, including in-line mixers will yield similar results but with potentially longer mix times. Mix time will be dependent upon the temperature, as well as the gap on the mill, or the amount of shear generated. Slow speed agitation with high temperatures do not produce the desired batch properties.
There are numerous benefits to the asphaltic formulations according to the present invention that utilize recycled polyethylene and/or polypropylene waxes in combination with the other components set forth herein. For example, it has been found that compared to conventional asphaltic formulations, the formulations provide increased hardness, which provides greater resistance to blister and greater scuff resistance. In addition, the formulations use less styrene butadiene styrene compounds compared to conventional asphalts and have a relatively reduced carbon footprint. The formulations also have relatively lower cost.
While the present invention has been described in terms of preferred and illustrated embodiments, it will be appreciated by those of ordinary skill that the spirit and scope of the invention is not limited to those embodiments, but extend to the various modifications and equivalents as defined in the appended claims
1. An asphalt composition comprising:
a. ground tire rubber having a mesh size between 10 and 80 mesh in an amount being about 2% to 7% of the composition;
b. radial styrene butadiene styrene in an amount being between about 1% to 7% of the composition;
c. linear styrene butadiene styrene in an amount being between about 1% to 7% of the composition;
d. polyethylene wax or polypropylene wax derived from post-consumer recycled waste in an amount being between about 1% and 5% of the composition;
e. wherein the balance of the composition is asphalt having between 20 to 220 penetration.
2. An asphalt composition comprising:
a. ground tire rubber having a mesh size between 10 and 80 mesh in an amount between 8-12% of the composition;
b. radial styrene butadiene styrene in an amount being between about 1% to 5% of the composition;
c. linear styrene butadiene styrene in an amount being between about 1% to 5% of the composition;
d. polyethylene wax or polypropylene wax derived from post-consumer recycled waste in an amount being between about 1% and 5% of the composition;
e. wherein the balance of the composition is asphalt having between 20 to 220 penetration.
3. An asphalt composition comprising:
a. ground tire rubber having a mesh size between 10 and 80 mesh in an amount between 4-8% of the composition;
b. radial styrene butadiene styrene in an amount being between about 1% to 7% of the composition;
c. polyethylene wax or polypropylene wax derived from post-consumer recycled waste in an amount being between about 1% and 7% of the composition;
d. wherein the balance of the composition is asphalt having between 20 to 220 penetration.