WO1993014423A1 - Glass beads embedded into high density polyethylene substrate for use as retroreflective articles, namely fencing - Google Patents
Glass beads embedded into high density polyethylene substrate for use as retroreflective articles, namely fencing Download PDFInfo
- Publication number
- WO1993014423A1 WO1993014423A1 PCT/US1992/000460 US9200460W WO9314423A1 WO 1993014423 A1 WO1993014423 A1 WO 1993014423A1 US 9200460 W US9200460 W US 9200460W WO 9314423 A1 WO9314423 A1 WO 9314423A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- beads
- plastic
- article
- diameter
- substrate
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
- B29C70/58—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising fillers only, e.g. particles, powder, beads, flakes, spheres
- B29C70/64—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising fillers only, e.g. particles, powder, beads, flakes, spheres the filler influencing the surface characteristics of the material, e.g. by concentrating near the surface or by incorporating in the surface by force
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
- E01F13/00—Arrangements for obstructing or restricting traffic, e.g. gates, barricades ; Preventing passage of vehicles of selected category or dimensions
- E01F13/02—Arrangements for obstructing or restricting traffic, e.g. gates, barricades ; Preventing passage of vehicles of selected category or dimensions free-standing; portable, e.g. for guarding open manholes ; Portable signs or signals specially adapted for fitting to portable barriers
- E01F13/028—Flexible barrier members, e.g. cords; Means for rendering same conspicuous; Adapted supports, e.g. with storage reel
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
- E01F7/00—Devices affording protection against snow, sand drifts, side-wind effects, snowslides, avalanches or falling rocks; Anti-dazzle arrangements ; Sight-screens for roads, e.g. to mask accident site
- E01F7/04—Devices affording protection against snowslides, avalanches or falling rocks, e.g. avalanche preventing structures, galleries
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/12—Reflex reflectors
- G02B5/126—Reflex reflectors including curved refracting surface
- G02B5/128—Reflex reflectors including curved refracting surface transparent spheres being embedded in matrix
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
- B29K2023/04—Polymers of ethylene
- B29K2023/06—PE, i.e. polyethylene
- B29K2023/0608—PE, i.e. polyethylene characterised by its density
- B29K2023/065—HDPE, i.e. high density polyethylene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2011/00—Optical elements, e.g. lenses, prisms
- B29L2011/0083—Reflectors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/73—Fences
Definitions
- This invention relates to retroreflective articles, and more particularly to fencing made of a high density polyethylene substrate wfth reflective glass beads, sometimes referred to as microspheres embedded therein.
- U.S. Patent 4,950,525 relates to "Elastomeric Reflective Sheeting" in which beads are embedded in a polymeric sheet. However, the sheet is then covered with a covering layer 19c (see column 5, lines 25-32 for a description of the final product).
- U.S. Patent 4,104,102 is somewhat similar to 4,950,525 in that the glass beads are covered with a sealing layer.
- U.S. Patent 3,873,390 makes use of glass beads (column 13) which are adhered with an adhesive (Fig. 5).
- U.S. Patent 4,505,967 describes retroreflectrve sheeting in which
- the microspheres are embedded into a first polymeric layer to less than one- half the average diameter of the microspheres and a film is laminated to the
- microsphere covered surface of the first layer is the microsphere covered surface of the first layer.
- U.S. Patent 4,648,932 also relates to retroreflective sheeting
- microspheres are embedded into a first polymeric layer to less than one-half their diameter and a covering film is placed over the microspheres.
- U.S. Patent 4,876,141 relates to a technique in which a mixture of
- materials including the glass beads or microspheres are formed into a sheet, the beads having a variety of exposed surfaces.
- U.S. Patent 4,897,136 describes retroreflective sheeting wherein a cover film is utilized over microspheres.
- beads in pavement marking material are heated to a temperature below their melting point but above the melting point of the existing
- thermoplastic pavement marking material into which they are to be
- the beads are then dropped onto the marking material and heat
- the invention specifically relates to the provision of reflective
- Japanese Patent 57-186702 is of general interest regarding embedded glass spheres in which an adhesive is utilized.
- the art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is "prior art" with respect to this invention, unless specifically designated as such.
- this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. ⁇ 1.56(a) exists.
- the present invention relates to a process and the resultant article in which retroreflective plastic articles, namely plastic fencing in the preferred embodiment, are prepared by embedding glass beads in plastic or
- thermoplastic materials such as high density polyethylene (HDPE).
- HDPE high density polyethylene
- the glass beads are heated and the thermoplastic material is softened by contact with the heated beads. Pressure is applied to the beads to embed them into the substrate at least 50% of their diameter but no greater than 70% of their diameter.
- the resulting product has superior durability and abrasion resistance.
- the 50-70% embedment of the beads in the present invention offers an advantage over the existing art in that no covering layer is necessary to retain the beads in their embedded position in the thermoplastic substrate.
- Fig. 1 is a fragmentary perspective view of the plastic reflective
- FIG. 2 is a greatly enlarged perspective detail view
- Fig. 3 is a side view of a schematic of the inventive embedment process as applied to plastic fencing
- Fig. 4 is an overhead view of a schematic of the inventive
- FIG. 5 is a schematic detail of a portion of Figs. 3 & 4, showing the glass bead hopper in more detail;
- Fig. 6 is a conceptual diagram of the embedment of a glass bead into a plastic substrate according to the invention. Description Of The Preferred Embodiments While this invention may be embodied in many different forms, there is shown in the drawings and described in detail herein a specific
- FIG. 1 a fragment of the retroreflective fencing material comprising glass beads embedded in a plastic substrate is shown generally at 10.
- the fencing material 12 has panels 50 separated by rows of perforations 52.
- the perforations are separated by strips 54.
- Glass beads 30 are embedded in panels 50 to form reflective strips 56, imparting reflective quality to fencing material 12.
- present inventive process is on fencing material made of high density polyethylene (HDPE) blended with polypropylene, for example 90% HDPE and
- the process may be utilized with any plastic or thermoplastic substrate.
- Glass bead hopper(s) 28 contains glass beads 30. More than one hopper may be utilized as can be seen in Fig. 4. The most preferred type of glass beads are size 11 , sign
- silica glass beads with a refractive index of 1.91 commercially available from Flex-O-Ute, P.O. Box 4366, St. Louis, MO 63123. As shown in
- glass beads 30 descend through neck 29 of hopper 28 and are heated by electrical heaters 32 situated on opposite sides of neck 29. Although any temperature well above the melting point of the plastic substrate and below the temperature of the glass beads may be used, a temperature of
- Electrical heater 32 is set at a temperature between 920°-960°F to produce a bead temperature of about 900° F.
- a simple mechanical valve 27 located in neck 29 of glass bead hopper 28 controls the flow of glass beads
- Beads 30 from hopper 28. It may be remotely activated. Beads 30 may therefore be released continuously or intermittently, controlled by valve 27.
- Heated glass beads 30 flow through nozzle 34 and meet deflector(s) 36, which deflects the beads so they evenly disperse over the width of reflective strip 56.
- a plurality of glass hoppers 28 continuously release glass beads 30 onto panels 50 of fencing material 12, forming reflective strips 56.
- Fig. 4 shows three glass bead application units which apply reflective glass bead strips 56 to fencing material 12.
- the apparatus shown will accommodate fencing material of up to 48" wide. The process may, however, be used on plastic material of any width.
- the fence is shown with three reflective strips 56 on alternating panels, the process may employ as many as ten or more application units, depending on the configuration of the fencing material used.
- the thermal energy of glass beads 30 is used to melt the plastic substrate as it comes in contact with glass beads 30. A load is applied to the
- nip roll 38 (best seen in Fig. 3) to displace molten plastic and increase the surface area in contact to promote heat transfer.
- the thermal energy and load applied must be set to embed the glass bead to approximately 50% of its diameter into the original substrate surface, and no more than 70%.
- the molten plastic flows up around the glass beads to provide a physical lock of the beads into the plastic surface.
- Embedment depth is important for two reasons, first to provide a positive lock of the beads and second, for the retroreflectrvity performance of the glass bead. Embedment depth must be greater than 50% for physically locking the beads into the surface, producing product durability.
- Embedment depth determines the maximum angle at which the product (substrate surface or plane) can be rotated away from 90° of the light source and remain retroreflective.
- a maximum embedment depth of 70% of the beads' diameter is critical to maintain product performance.
- This application method of embedding the glass beads into the plastic substrate surface uses no adhesives or binders to hold or retain the reflective glass beads onto the surface.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP92905243A EP0623224A1 (en) | 1992-01-21 | 1992-01-21 | Glass beads embedded into high density polyethylene substrate for use as retroreflective articles, namely fencing |
PCT/US1992/000460 WO1993014423A1 (en) | 1992-01-21 | 1992-01-21 | Glass beads embedded into high density polyethylene substrate for use as retroreflective articles, namely fencing |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/US1992/000460 WO1993014423A1 (en) | 1992-01-21 | 1992-01-21 | Glass beads embedded into high density polyethylene substrate for use as retroreflective articles, namely fencing |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1993014423A1 true WO1993014423A1 (en) | 1993-07-22 |
Family
ID=22230738
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1992/000460 WO1993014423A1 (en) | 1992-01-21 | 1992-01-21 | Glass beads embedded into high density polyethylene substrate for use as retroreflective articles, namely fencing |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0623224A1 (en) |
WO (1) | WO1993014423A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997023788A1 (en) * | 1995-12-22 | 1997-07-03 | Norsk Hydro Asa | Retro-reflecting sheet material and method of preparing such material |
US20150343502A1 (en) * | 2012-12-20 | 2015-12-03 | 3M Innovative Properties Company | Anti-soiling, abrasion resistant constructions and methods of making |
US9758656B2 (en) | 2013-08-28 | 2017-09-12 | Sabic Global Technologies B.V. | Soft touch compositions and articles thereof |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2345644A (en) * | 1942-04-01 | 1944-04-04 | Cast Stone Inst | Light reflecting sign or marker |
US3563781A (en) * | 1967-12-11 | 1971-02-16 | Minnesota Mining & Mfg | Method of providing retro-reflective stripes on cylindrical surfaces |
US3989775A (en) * | 1971-03-01 | 1976-11-02 | Bakelite Xylonite Limited | Method of making a retro-reflective beaded material |
US4221498A (en) * | 1979-05-07 | 1980-09-09 | Astro Optics Corporation | Roadside barrier reflector |
US4272564A (en) * | 1979-06-27 | 1981-06-09 | C. M. Offray & Son, Inc. | Flexible reflex-reflective article having undulant surface and method of making the same |
US4569857A (en) * | 1979-10-01 | 1986-02-11 | Minnesota Mining And Manufacturing Company | Retroreflective sheeting |
US4626127A (en) * | 1983-04-11 | 1986-12-02 | May David C | Elastomeric pavement marker |
US4983458A (en) * | 1984-09-21 | 1991-01-08 | Potters Industries, Inc. | Reflective particles |
US5039557A (en) * | 1989-10-26 | 1991-08-13 | White Terrence H | Method for embedding reflective beads in thermoplastic pavement marking lines |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3836227A (en) * | 1973-04-13 | 1974-09-17 | Minnesota Mining & Mfg | Heat-bondable retroreflective sheeting |
US4983436A (en) * | 1987-04-15 | 1991-01-08 | Minnesota Mining And Manufacturing Company | Retroreflective sheeting with backing film |
-
1992
- 1992-01-21 EP EP92905243A patent/EP0623224A1/en not_active Withdrawn
- 1992-01-21 WO PCT/US1992/000460 patent/WO1993014423A1/en not_active Application Discontinuation
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2345644A (en) * | 1942-04-01 | 1944-04-04 | Cast Stone Inst | Light reflecting sign or marker |
US3563781A (en) * | 1967-12-11 | 1971-02-16 | Minnesota Mining & Mfg | Method of providing retro-reflective stripes on cylindrical surfaces |
US3989775A (en) * | 1971-03-01 | 1976-11-02 | Bakelite Xylonite Limited | Method of making a retro-reflective beaded material |
US4221498A (en) * | 1979-05-07 | 1980-09-09 | Astro Optics Corporation | Roadside barrier reflector |
US4272564A (en) * | 1979-06-27 | 1981-06-09 | C. M. Offray & Son, Inc. | Flexible reflex-reflective article having undulant surface and method of making the same |
US4569857A (en) * | 1979-10-01 | 1986-02-11 | Minnesota Mining And Manufacturing Company | Retroreflective sheeting |
US4626127A (en) * | 1983-04-11 | 1986-12-02 | May David C | Elastomeric pavement marker |
US4983458A (en) * | 1984-09-21 | 1991-01-08 | Potters Industries, Inc. | Reflective particles |
US5039557A (en) * | 1989-10-26 | 1991-08-13 | White Terrence H | Method for embedding reflective beads in thermoplastic pavement marking lines |
Non-Patent Citations (1)
Title |
---|
See also references of EP0623224A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997023788A1 (en) * | 1995-12-22 | 1997-07-03 | Norsk Hydro Asa | Retro-reflecting sheet material and method of preparing such material |
US20150343502A1 (en) * | 2012-12-20 | 2015-12-03 | 3M Innovative Properties Company | Anti-soiling, abrasion resistant constructions and methods of making |
US9758656B2 (en) | 2013-08-28 | 2017-09-12 | Sabic Global Technologies B.V. | Soft touch compositions and articles thereof |
Also Published As
Publication number | Publication date |
---|---|
EP0623224A4 (en) | 1994-08-25 |
EP0623224A1 (en) | 1994-11-09 |
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