GREENHOUSE SCREEN

• US 20130008082A1
• Filed: 02/04/2011
• Published: 01/10/2013
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• Current Assignee: Ab Ludvig Svensson
• Original Assignee: Ab Ludvig Svensson
• Inventors: Andersson, Hans, Holgerson, Per
• Granted Patent: US 9,003,698 B2
• Time in Patent Office: Days
• US Class Current: 47/17
• CPC Class Codes: A01G 9/22 Shades or blinds for greenhouses, or the like
• CPC Class Codes: B32B 15/043 of metal B32B15/01 takes precedence
• CPC Class Codes: B32B 15/09 comprising polyesters
• CPC Class Codes: B32B 2250/20 All layers being fibrous or filamentary
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2264/108 Carbon, e.g. graphite particles
• CPC Class Codes: B32B 2307/3065 Flame resistant or retardant, fire resistant or retardant
• CPC Class Codes: B32B 2307/40 having particular optical properties light or UV resistant B32B2307/71
• CPC Class Codes: B32B 2307/402 Coloured
• CPC Class Codes: B32B 2307/41 Opaque
• CPC Class Codes: B32B 2307/516 mono-axially
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 2307/71 Resistive to light or to UV
• CPC Class Codes: B32B 2307/732 Dimensional properties
• CPC Class Codes: B32B 2571/00 Protective equipment
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 3/10 characterised by a discontinuous layer, i.e. formed of separate pieces of material
• CPC Class Codes: D03D 1/007 UV radiation protecting
• CPC Class Codes: D03D 11/00 Double or multi-ply fabrics not otherwise provided for
• CPC Class Codes: D03D 15/46 : Flat yarns, e.g. tapes or films
• CPC Class Codes: D03D 15/54 : coloured
• CPC Class Codes: D03D 9/00 : Open-work fabrics
• CPC Class Codes: D04B 21/16 : incorporating synthetic threads
• CPC Class Codes: D10B 2331/04 : polyesters, e.g. polyethylene terephthalate [PET]
• CPC Class Codes: D10B 2401/22 : protective against sunlight or UV radiation
• CPC Class Codes: D10B 2403/0243 : enhancing functional properties
• CPC Class Codes: D10B 2505/18 : Outdoor fabrics, e.g. tents, tarpaulins D10B2507/00 takes precedence
• CPC Class Codes: Y02A 40/25 : Greenhouse technology, e.g. cooling systems therefor
• CPC Class Codes: Y10T 442/3033 : Including a strip or ribbon
• CPC Class Codes: Y10T 442/406 : Including parallel strips
• CPC Class Codes: Y10T 442/456 : Including additional strand inserted within knit fabric
• CPC Class Codes: Y10T 442/463 : Warp knit insert strand

Abstract

The invention refers to a greenhouse screen comprising strips of film material that are interconnected by a yarn system by means of hosiery, knitting, warp-knitting or weaving process to form a continuous product. At least some of the strips comprise a film material in the form of a multilayer polyester film having a thickness less than 60 μm and comprising at least two layers, wherein at least one layer is white and at least one layer is black, said at least one white layer comprises polyester and a white pigment in an amount between 5 and 50 weight-% based on the total weight of said white layer, and said at least one black layer comprises polyester and a black opacifying agent.

Claims

1. A greenhouse screen comprising strips of film material that are interconnected by a yarn system by means of hosiery, knitting, warp-knitting or weaving process to form a continuous product, wherein at least some of the strips comprise a film material in the form of a multilayer polyester film having a thickness less than 60 μ

m and comprising at least two layers, wherein at least one layer is white and at least one layer is black, said at least one white layer comprises polyester and a white pigment in an amount between 5 and 50 weight-% based on the total weight of said white layer, and said at least one black layer comprises polyester and a black opacifying agent.

2. A greenhouse screen as claimed in claim 1, wherein said multilayer polyester film comprises at least three layers:

at least two white layers and at least one black layer.

3. A greenhouse screen as claimed in claim 2, wherein the film comprises white layers as outer cover layers and a black layer as a middle layer.

4. A greenhouse screen as claimed in claim 2, wherein the film comprises a first white layer and a black layer as outer cover layers and a second white layer as a middle layer.

5. A greenhouse screen as claimed in claim 2, wherein the outer cover layers each have thickness at least 4 μ

m and not more than 15 μ

m.

6. A greenhouse screen as claimed in claim 2, wherein the middle layer has a thickness that amounts to at least 50% of the total thickness of the film.

7. A greenhouse screen as claimed in claim 1, wherein said multilayer polyester film is a two-layer film comprising one white layer having a thickness of at least 4 μ

m and a black layer.

8. A greenhouse screen as claimed in claim 1, wherein the white layer(s) comprise(s) at least 15 weight-% white pigment based on the total weight of said white layer.

10. A greenhouse screen as claimed in claim 1, wherein the black layer contains between 0.2 and 15 weight-% black opacifying agent based on the total weight of said black layer.

11. A greenhouse screen as claimed in claim 10, wherein the black opacifying agent is carbon black.

12. A greenhouse screen as claimed in claim 1, wherein the thickness of said multilayer polyester film is equal to or less than 45 μ

m.

13. A greenhouse screen as claimed in claim 1, wherein the multilayer polyester film comprises a flame retardant agent.

14. A greenhouse screen as claimed in claim 13, wherein the flame retardant agent is a phosphorous-containing flame retardant and that the multilayer polyester film comprises between 1500 and 3500 ppm phosphorous.

15. A greenhouse screen as claimed in claim 13, wherein the flame retardant is a copolymerisable phosphorus-containing flame retardant compound selected from compounds of formula (I):

16. A greenhouse screen as claimed in claim 1, wherein the black layer comprises between 1 and 25 weight-% white pigment based on the total weight of said black layer.

17. A greenhouse screen as claimed in claim 1, wherein the white layer comprises between 0.05 and 5 weight-% of a UV-stabilizer.

18. A greenhouse screen as claimed in claim 1, wherein the multilayer polyester film is at least uniaxially and preferably biaxially drawn.

19. A greenhouse screen as claimed in claim 1, wherein said strips of said multilayer polyester film form at least 20% of the surface area of the greenhouse screen.

20. A greenhouse screen as claimed in claim 1, wherein all strips in said screen are of said multilayer polyester film and are arranged closely edge to edge, so that they form a substantially continuous surface.

21. A greenhouse screen as claimed in claim 1, wherein the screen comprises open areas that are free from strips of film material.

22. A greenhouse screen as claimed in claim 1, wherein the strips extend in a longitudinal direction of the screen and are held together by a yarn framework comprising longitudinally extending warp threads and transverse connection threads extending across the strips and connecting to the warp threads, at least said longitudinally extending warp threads are of black yarn.

23. A greenhouse screen as claimed in claim 22, wherein said transverse connection threads extending over a white surface of the strips are of transparent or white yarn and the transverse connection threads extending over a black surface of the strips are of black yarn.

9. A greenhouse screen as claimed in wherein said white pigment is TiO₂.