Claims
- 1. A method of making a pavement marking sheet material comprising the steps of:
- 1) providing a continuous polymeric base sheet having a plurality of protuberances on its upper surface,
- said upper surface being made up of a plurality of segments arranged in a selected manner,
- each said segment having a front edge, rear edge, and two side edges, and having one protuberance or an array of a plurality of said protuberances positioned along said front edge and a spacing zone that is free of said protuberance or array of a plurality of protuberances along said rear edge such that said protuberance or array of a plurality of protuberances are positioned closer to said front edge than to said rear edge, the longitudinal length L of said spacing zone being greater than H/tan(90.degree.-.theta.), where H is the height of said protuberance or array of a plurality of protuberances and .theta. is a design entrance angle that falls within the range of 86.9.degree. to 8.9.6.degree.;
- 2) applying a fluid coating to each protuberance;
- 3) depositing coated microspheres onto the fluid coating and allowing the microspheres to become partially embedded in the coating; and
- 4) solidifying said fluid coating.
- 2. The method of claim 1 wherein said fluid coating comprises reflective pigments.
- 3. The method of claim 2 wherein said fluid coating comprises reflective pigments and UV-fluorescent pigments.
- 4. The method of claim 1, wherein:
- the design entrance angle .theta. falls within the range of 88.5.degree. to 89.6.degree..
- 5. The method of claim 1, wherein:
- the design entrance angle .theta. falls within the range of 89.3.degree. to 89.6.degree..
- 6. The method of claim 1, wherein:
- said microspheres have an index of refraction of between about 1.75 and about 2.0.
- 7. The method of claim 1, wherein:
- said microspheres have an average diameter from about 50 micrometers to about 600 micrometers.
- 8. The method of claim 1, wherein:
- said microspheres are embedded to a depth of approximately 40 to 65 percent of their average diameter.
Parent Case Info
This is a division of application Ser. No. 08/247,050, filed May 20, 1994, now abandoned.
US Referenced Citations (28)
Foreign Referenced Citations (1)
Number |
Date |
Country |
373826 |
Jun 1990 |
EPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
247050 |
May 1994 |
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