Abstract:
A horticultural cut flower container assembly comprising a plastic bag with a cup shaped base member of flexible foam material secured to the bag, the cup shaped foam material being adapted to receive the stem ends of a bunch of piece of cut flowers and a strap mounted to the bag encircling the bag and stem ends to hold said stem ends in said bag in a secured position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The application is a continuation-in-part of U.S. patent application Ser. No. 10/670,531 filed on Sep. 26, 2003. 
     
    
     TECHNICAL FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to the use of a bag wrap for transporting cut flowers and plants. More particularly, this invention relates to a plastic bag having an internal cup shaped stem wrap formed of polyisocyanate foam material using diphenylmethane diisocyanates which holds flower stems and is secured with a strap which is secured around the bag.  
       BACKGROUND OF THE INVENTION  
       [0003]     I. Field of the Invention  
         [0004]     The present invention relates generally to floriculture. In particular, the present invention relates to a device and method for holding the stems of cut flowers during shipment and hydrating the flowers.  
         [0005]     II. Discussion of Background  
         [0006]     The flower industry is a multi-billion dollar industry worldwide. In the U.S. alone, sales of cut roses exceed hundreds of million dollars per year. The most popular varieties of rose often retail for several dollars per rose. Sales of other cut flowers and plants such as bamboo are also substantial.  
         [0007]     It is a common practice to sustain the life of cut flowers by means of inserting the end of the plant stem in a reservoir containing a liquid such as water. Flowers start to wilt just a few hours after cutting unless they are supplied with water and nutrients. The first indication of wilting is when the stem starts to bend just below the flower head. As the stem bends, the flower head droops and the flow of water up the stem is impeded. Soon afterwards, the flower petals start to discolor and the flower dies. In shipment from the grower, cut flowers are generally wrapped in newspaper or shredded paper or fiber and covered with a paper or plastic sleeve. In shipping the cut flowers are often stored under uncontrolled temperatures which can cause dehydration and destruction of lots or individual flowers.  
         [0008]     Many techniques are available for extending the useful life of cut flowers, including changing their water regularly, adding preservatives to the water, trimming the stems, keeping the flowers away from direct sunlight, and refrigerating them. Even when such precautions are taken, cut flowers start to wilt after a few days.  
         [0009]     A number of devices have been used for supporting and shipping cut flowers. For example, a spacing disc for a conical paper flower container having a plurality of spaced tear-shaped openings for holding flower stems as is shown by U.S. Pat. No. 3,767,104 issued Oct. 23, 1973. Flowers can be fixed to a continuous strip, which is then rolled in such a fashion that the flowers are isolated from one another to facilitate storage and transport as is shown by U.S. Pat. No. 3,657,840 issued Apr. 25, 1972. Holders for cut flowers include a flexible paper cover for protecting the flower petals as shown by U.S. Pat. No. 3,271,922 issued Sep. 13, 1966 and a cardboard sleeve for receiving the stems as shown by U.S. Pat. No. 2,247,191 issued Jun. 24, 1941. A waterproof wrapper for corsage stems is shown by U.S. Pat. No. 1,044,260 issued Nov. 12, 1912.  
         [0010]     There is a need for a simple, easy-to-use container for cut flowers which keep the flowers hydrated during wholesale shipment and/or delivery from the florist to the end user. The container should not damage the stems of the flower when wrapped and should hold the stems firmly, allowing air water and nutrients to contact each stem and be simple and inexpensive to manufacture.  
       SUMMARY OF THE INVENTION  
       [0011]     A plastic bag with an inner base of shaped foam material is wrapped over the cut ends of the stems of cut flowers to form a wrap covering the stems. The wrap is held in place with a plastic strap which is wrapped around the outer bag over the ends of the stems. The inner base portion of the wrap is constructed of a sterile diphenylmethane diisocyanate (MDI) foam material having at least 50% of its pores ranging in size from 10 to 200 microns. If desired the foam material can be of an organic polyisocyanate foam material using one or more of crude, polymeric, 4,4′-, 2,4′- and 2,2′-diphenylmethane diisocyanates with a soy based polyol ranging from 10% to 25% having a low density. The bag is inverted so that the foam material is positioned outside the bag and is dipped into water and nutrient, and the stems are placed into the base and the bag is then pulled over the base and stems and held securely with a strap.  
         [0012]     The present invention provides a novel cut plant container for providing liquid to a cut flower wherein a substantial amount of the liquid required by the plant is presented to the cut end of the plant stem for preserving the life of a cut flower.  
         [0013]     It is an object of the invention to provide a horticultural container for cut flowers having a homogeneous horticultural foam material base which is sterile.  
         [0014]     It is another object of the invention to provide a horticultural container for cut flowers which hydrates flowers in shipment.  
         [0015]     It is yet another object of the invention to provide a horticultural container for cut flowers which directs water held in the foam to the stems.  
         [0016]     It is still another object of the invention to provide a horticultural container for cut flowers which can be economically fabricated to fit a wide variety of stem bunch sizes.  
         [0017]     It is another object of the invention to provide a horticultural container for cut flowers which can be easily applied by the shipper or florist to bunches of cut flowers.,  
         [0018]     These and other objects, advantages, and novel features of the present invention will become apparent when considered with the teachings contained in the detailed disclosure along with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]      FIG. 1  is a perspective view of wrap invention with a broken away portion of flower stems being placed into the middle of the foam base of the plastic bag wrap;  
         [0020]      FIG. 2  is a perspective sequential view of the foam wrap of  FIG. 1  with the bag lip portion pulled back over the bag and flower stems which are seated in the interior of the foam base of the plastic bag wrap;  
         [0021]      FIG. 3  is a sequential perspective view of the wrap invention of  FIG. 2  showing the strap portion of the bag being placed around the bag and the stems;  
         [0022]      FIG. 4  is a sequential perspective view of  FIG. 3  showing the strap secured around the bag and stems;  
         [0023]      FIG. 5  is an enlarged perspective view of the fully inverted bag of  FIG. 1  showing the cup shaped foam base structure before stems are placed in the base structure and the bag is placed around the stems; and  
         [0024]      FIG. 6  is a plan view of the base foam structure before the same is folded and glued and secured in the bottom of the plastic bag wrap. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     The preferred embodiment and best mode of the invention is shown in  FIGS. 1 through 6 .  
         [0026]     The invention is directed toward a rectangular shaped foam member  10  formed of an aromatic polyisocyanate polymer diphenylmethane diisocyanate (MDI) flexible foam material using no filler material which hydrates cut flowers in shipment by directing water absorbed in the foam wrap to the stems.  
         [0027]     The polyisocyanate used in the foam material is an aromatic polyisocyanate which includes aromatic diisocyanates having 6 to 16 carbon atoms (excluding those contained in NCO groups; this applies to the polyisocyanates mentioned below), aromatic triisocyanates having 6 to 20 carbon atoms and crude products of these isocyanates, etc. Examples of aromatic polyisocyanate include 1,3- and 1,4-phenylene diisocyanates, 2,4- and/or 2,6-tolylene diisocyanates (TDI), crude TDI and 2,4′- and/or 4,4′-diphenylmethane diisocyanate (MDI) as well as crude MDI.  
         [0028]     The preferred material which is used as the foam material in the invention is one or more of 2,2′-, 2,4′- and 4,4′-diphenylmethane diisocyanate (MDI), crude MDI, products of crude diaminodiphenyl methane where the crude diaminodiphenyl methane is a polymeric MDI or a mixture of the same; or is a mixture of diaminodiphenyl methane and a small amount (e.g., 5 to 20 mass %) of a polyamine having three or more functional groups; polyallyl polyisocyanate (PAPI), etc. If a fully biodegradable material is desired, an organic polyisocyanate foam material using one or more of crude, polymeric, 4,4′-, 2,4′- and 2,2′-diphenylmethane diisocyanates with a soy based polyol ranging from 10% to 25% having a low density is used.  
         [0029]     Such material is readily obtained in the market place and examples of same for purposes of showing commercial availability but which should not be construed as limiting are: BASF M-20S, and Rubinate 1680, Rubinate 1790, Rubinate 7302, Rubinate 7400, Rubinate 8700, Rubinate 9410 and Suprasec DNR all of which are available from ICI Americas.  
         [0030]     The material is foamed in a conventional manner with a blowing agent such as carboxylic acids and anhydrides. It is important that no filler material is added to the foamed material and the material is substantially sterile with a neutral pH ranging from 6.8 to 7.8. The term substantially sterile is used in a horticultural sense and not as a medical term meaning the material is free from plant disease, microbes, fungus, insects, disease, algae and animal life.  
         [0031]     The material has a pore size with total porosity ranging from 85% to 95%, preferably from 90% to 92% with an air space ranging from 25 to 35%, preferably about 30%. Air space is the percent volume of a component which is filled with air after the material is saturated and allowed to drain. For a given density and moisture content, Total Porosity+Container Capacity+Air Space. The present invention has a density of 1.00 to 3.00 preferably about 1.35 pounds per cubic foot and tensile strength ranging from 7.5 to 9.5, preferably at 8.0 psi per minute. The tear strength ranges from 0.18 to 0.22, preferably 0.2. Total porosity is the percent by volume of the foam that is comprised of pores. This is the volume fraction which provides the water and aeration in the foam material. The total porosity+the percent solids=100%. At least 40% to 60%, preferably about 50% of the foam material volume of the material contains pores ranging in size between 10 and 200 microns, preferably from about 40 to about 90 microns. These pores sizes are defined as mesopores which are responsible for water retention.  
         [0032]     The micropore fraction (0.2 to 10 microns) of the foam material may range from 15% to 25% by foam volume, and preferably is held constant at about 20%. Micropores are responsible for water reserve and consist of open and closed pore cubic inch of foam.  
         [0033]     The macropore fraction of the foam material ranges from 25% to 35%, preferably about 30% of the foam volume and contains pores ranging in size between 300-800 microns. These macropores are responsible for drainage and aeration.  
         [0034]     The rectangular shaped foam base member  10  as shown in  FIG. 5  has corner slits  12  cut inward from the corners  14  and extending inward to a base section  16  to form end and side panels. The thickness of the foam material ranges from ¼ inch to 1½ inch with the preferred thickness being ¼ inch. The side panels  18  and end panels  20  are folded upward and overlap as is shown in  FIG. 5 . The side panels and end panels  20  are glued together preferably with a water based glue to form a cup shaped structure  22  at the bottom of the bag. Other suitable adhesives can be used. The cup structure  22  is glued to the bottom of the bag  30  and the sides  32  of the bag to hold the cup structure  22  securely in place inside the bag. The bag is constructed of plastic preferably of polyethylene, with an upper lip portion  32  which is folded down over the bag body and has a strap  34  integrally formed therewith which can then be wrapped around the bag and flower stems  40 . The strap  34  is provided with several adhesive areas  36  as shown in  FIG. 5  allowing it to be secured to the bag body holding the stems in place or it can be provided with VELCRO fastening strips  38  as shown in  FIGS. 1-4  which allow it to be fastened to itself holding the flower stems  40  firmly in place.  
         [0035]     The bag  30  is inverted and the cup structure  22  glued to the bottom of the bag is then soaked with water and such preservatives and nutrients as required. The bag  30  is pulled back over the cup structure  22  to form a base for the flower stems. As is shown in  FIG. 1 , the flower stems  40  of a bunch of flowers are placed in the middle base section  16  of the foam structure member  10 . The bag lip  32  is folded back over the bag body  30  and the strap  34  is fastened around the lip and bag using either the adhesive areas  36  as shown in  FIG. 5  or the VELCRO loop fasteners as shown in  FIGS. 1-4 .  
         [0036]      FIG. 4  shows the final package of the flower stems  40  and wrap with the plastic bag  30  being sealed by the strap or band  34 .  
         [0037]     The principles, preferred embodiments and modes of operation of the present invention have been described in the foregoing specification. However, the invention should not be construed as limited to the particular embodiments which have been described above. Instead, the embodiments described here should be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the scope of the present inventions defined by the following claims.