This invention relates to a method and apparatus for forming three-dimensional shaped products particularly plant container liners from in particular sphagnum moss. Such liners are useful in lining hanging baskets, especially those baskets in the form of skeletal containers.
Because of its unique water retaining properties, and pleasant appearance as a natural plant substance, sphagnum moss has traditionally been a favoured material for use in conjunction with floral arrangements and related horticultural activities. Sphagnum moss is sold mostly in a dried state but sometimes in a wet state, generally in a natural loose form. Sphagnum moss is commonly used to line hanging baskets. One reason for this is its particular ability to absorb and retain water up to and exceeding twenty times its own weight. Another is its natural and aesthetically pleasing appearance.
The most common traditional method of using sphagnum moss to line a hanging basket is to place some loose moss in the bottom of the wire basket, then cover the moss with a little potting mix—the basket is gradually filled, by building up the outer layer of sphagnum moss around the outside of the basket and by holding it in place with a little more soil and potting mix. This is repeated several times until the lining of sphagnum moss reaches toward the upper rim of the hanging basket. This method is labour intensive, and is mostly performed at home by the enthusiastic gardener, and sometimes by staff in garden centres. In this form, baskets with a lining layer of sphagnum moss can be made available only when they are filled with soil and potting mix, because it is the soil and potting mix which holds the outer lining of loose filaments of moss in place. There is a limited scope for selling sphagnum moss lined hanging baskets in this form. The labour content in filling them is high. In addition, transporting baskets in this form from one location to another can be very difficult and costly. Thus sphagnum lined hanging baskets filled in this way for sale would normally have to be made and sold in the same garden centre. They are impractical to manufacture on a large scale using technology and production machinery, and then transport in bulk nationally and internationally to many retail outlets.
One company in the USA has created a moss lined hanging basket which can much more readily be transported in cartons as freight, or even posted in the mail, which makes them much more marketable. The short filaments of loose moss are fixed onto the outside of the basket with very fine filament or wire—much like fishing net. Soil or potting mix is not required to hold the moss in place. However the process of sewing the filaments or moss onto the outside of the basket is also time consuming and such moss lined basket are essentially hand crafted items.
Through the use of heavy pressure dry particulate sphagnum moss can be compressed into flat sheets that bind together due to the fiberous nature of this species of moss. The long filaments of New Zealand, Chilean and Tasmanian sphagnum moss are ideal for pressing. The sheets of compressed sphagnum moss are of various thickness, usually from 2 or 3 mm to about 7 mm. However the compressed dry, flat sheets are very brittle and crack easily. They are somewhat like balsa wood in terms of flexibility and they look somewhat like particle board in texture. In New Zealand, one company markets a compressed sphagnum moss product which when unfolded is shaped like a Maltese cross. This item is sold in flat configuration. The moss is so brittle in its compressed state that to protect it from damage when offered for sale, each liner must be protected by either first wrapping the liner in plastic then placing each liner inside a strong cardboard package or outer to protect the liner, or placing and packaging the liner inside a wire basket and then wrapping/sealing both the basket and the liner in plastic. The flat liner to be placed inside a hanging basket must first be wetted so that it partially reconstitutes, thus allowing it to be unfolded and moulded to fit in and contour to the shape of the basket. Disadvantages of this form of liner include:
In addition, market research shows that consumers often have difficulty in comprehending that the flat dry particle board-like product is actually a moss liner, and in determining how much water should be applied so that the liner can be made flexible:—too much water and the liner will fall apart, and too little water and the brittle liner will crack allowing soil to fall through the liner basket), the liner must often be further wetted to allow holes to be made for plants to be inserted.
U.S. Pat. No. 3,958,365 discloses a method for moulding tubs or pots from fibrous material which includes forming the fibres into a web and spraying the web with an emulsion before optionally moulding sections of the web into tubs or pots with a plunger-type mould.
PCT international patent application publications WO 00/32392 and WO 02/39806 and Australian patent application 87306/01 disclose forming plant container liners by forming flat blanks from sphagnum moss which are subsequently folded to form the three dimensional liners.
It is an object of the present invention to provide a method and apparatus for directly moulding such three dimensional planter liners from sphagnum moss.
In broad terms in one aspect the invention comprises apparatus for forming three dimensional shaped products from particulate sphagnum moss material including co-operating first and second die members arranged to move from an open configuration to a closed configuration to press form three dimensional shaped products from the particulate material, and a resiliently deformable web extending between the die members for carrying the particulate material thereon which will deform between the die members on each closing of the die members to allow the die members to press the particulate material to the three dimensional shape of the product.
Typically the die members include a cavity die part and a plunger die part arranged to press the particulate material on the deformable web into the cavity die part.
In broad terms in another aspect the invention comprises apparatus for forming three dimensional shaped products from particulate sphagnum moss material including:
a conveyor including a belt formed of a flexible and resiliently deformable material and arranged to carry on the belt of the conveyor the particulate material and arranged to move in steps, and
a press forming stage including a cavity die member positioned beneath the belt of the conveyor and including a shaped die cavity, and a co-operating die member positioned above the belt of the conveyor and arranged to move after each step forward of the conveyor which delivers fresh particulate moss material between the die members, to press the section of the belt of the conveyor between the die members and the particulate material thereon into the cavity die member, to form a shaped product.
Preferably the belt of the conveyor has sufficient resilience to lift the press formed product from the cavity die member after each operation of the press forming stage.
Preferably the apparatus includes means for continuously delivering particulate moss material onto the conveyor for conveying to the press forming stage and the conveyor is arranged to convey the formed products away from the press forming stage.
In broad terms in another aspect the invention comprises a method for forming three dimensional shaped products from particulate sphagnum moss material including providing co-operating first and second dies, carrying the particulate moss material on a resiliently deformable web extending between the die members, causing the die members to move from an open configuration to a closed configuration to press between the die members the resiliently deformable web and the particulate moss material thereon to the three dimensional shape of the product, and returning the die members to the open position to release the press-formed product.
In broad terms in a further aspect the invention comprises a method for forming three dimensional shaped products from particulate sphagnum moss material including:
carrying the particulate moss material to a press forming stage on a conveyor including a belt formed of a flexible and resiliently deformable material and arranged to move in steps, the press forming stage including a cavity die member positioned beneath the belt of the conveyor and including a shaped die cavity and a co-operating die member positioned above the belt of the conveyor, to press the section of the belt of the conveyor between the die members and the particulate material thereon into the cavity die member to form a shaped product, and
after each operation of the press forming stage causing the conveyor to step onto deliver fresh particulate material between the die members.
Preferably the particulate matter is moulded at a pressure of at least about 3000 psi.
Preferably the sphagnum moss is prepared prior to pressing so as to be substantially dry, yet slightly moist in a layer which is suitably thick. The preferred moisture level is 14-18% by weight and the preferred thickness is 130-150 mm. The thickness and moisture levels of the moss may be controlled so that the resulting three dimensional liner is made flexible and is not a brittle sheet.
The invention also includes three dimensional shaped items formed by the method and apparatus set out above.
This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.
Preferred forms of the invention are described by way of example with reference to the accompanying drawings in which:
a to 12d show a single operation of the moulding stage of the machine of
FIGS. 14 to 24 show different forms of sphagnum moss plant container liners which may be formed by the method and apparatus of the invention and their use; and
FIGS. 25 to 28 show plunger and cavity die parts for forming a wreath liner and the operation thereof
The sphagnum moss we use has long scaly strands, with relatively large leaves, which have the property that when dried and compressed using our process, the leaves and stems interlock in a flexible structure that retains its shape and is self-supporting without the use of glues or other supporting materials, and is still easily recognisable as moss. The sphagnum moss 100 is also used for its aesthetic value in hanging basket arrangements. The sphagnum moss is harvested from a natural and renewable source. Preferably about 40% of the sphagnum moss has strands exceeding 75 mm in length.
Initially excess water may be removed from the freshly harvested sphagnum moss 100 through the use of a centrifuge or calendar rolls. The sphagnum moss is then dried, either in a kiln for example or with natural sunlight. Preferably, the sphagnum moss if kiln dried is passed through a drying tunnel on a continuous conveyor, the speed of which is controllable to control the drying time. Suitably, an automatic feeding system (not shown) that deposits the moss onto the conveyor is also provided, such as a hopper into which moss is loaded and from which moss is deposited from an outlet onto the conveyor. The kiln may be in the form of a tunnel within which heated air is circulated, which may be generated from hot water heat exchangers operating at a temperature as high as 140° C. The moss is gradually dried as it travels through the kiln.
After drying, the moss may be left in piles to cool and reabsorb some moisture from the atmosphere. Optionally, additional moisture is then added to recondition the moss, through pressurised water misting nozzles for example. The desired amount of water added may be between 0.014 gm of water per cm2 of moss liner sheet and 0.070 gm of water per cm2 of moss liner sheet. Re-conditioning may be carried out over a 24 hour period and enables the moss to become supple and flexible. The optimum moisture content of the moss prior to pressing is 14 to 18 percent by weight, or less preferably.
After drying and re-conditioning the sphagnum moss is more readily able to be compressed into sheets 102 as illustrated in
Optionally for forming a liner of the shape shown in
In use moss 25 is spread over the flexible material 21/23 either before or after placing between the plunger and cavity die members, preferably within the confines of the dotted line 24 in
During operation the plunger die member 26 initially makes contact with the sphagnum moss 25 in the centre of the flexible material 21/23. As the plunger die member moves further the moss beneath the base of the plunger die member 26 is trapped between the plunger die member and the flexible web, and as the plunger die member 26 continues to move downwardly the sphagnum moss on the flexible web is caught between the tapered sides of the plunger die member 26 and the flexible web, and is pushed to shape into the die cavity 27a with a substantially even thickness of the moss. Moss accumulating at the base of the mould with an uneven distribution of moss in the finished liner is minimised. Preferably sphagnum moss is moulded at pressures ranging from 3000-4000 psi to bind the strands of sphagnum moss together without adhesives. After the plunger die member 26 has pushed the moss fully into the cavity die member 27, deforming the flexible web to its maximum extent so that the flexible web fully contacts the interior of the cavity die member 27, the plunger die member 26 then fully withdraws. The natural elasticity of the flexible web then tends to lift the moulded product from within the cavity die member 27. The moulded liner is removed, and the process can be repeated. After moulding, the annular lip of the liner may be trimmed as necessary.
Optionally, the peripheral rim of the die cavity 27b may include an annular recess so that a reduced degree of compression is applied to the moss in this area. The upper periphery of the resulting liner will then be less pressed and will retain some of the characteristics of unpressed moss, making the composition of the product more easily recognisable by potential customers. The depth of such a peripheral rim portion may be 2.5-3.5 cm for example.
The exterior of the compressed sphagnum moss liner typically has the appearance of cardboard and may not be easily recognisable to the purchasing public as a sphagnum moss liner. To bring the surface of the sphagnum moss liner to more closely resemble the original natural state of sphagnum moss, a fine mist of water may be optionally sprayed onto the exterior of the liner using an atomised fluid spray. The amount of water applied may for example be about 113-173 g/m2, preferably 143 g/m2. The temperature of the water is also preferably between 15-25° C. The resulting liner will then resemble that illustrated in
Use of a liner is shown in
FIGS. 9 to 13 show operation of an automated system for producing moss liners. In these figures similar reference numerals as in
Operation of the mould is similar in principle to that of
Moss may be deposited on the forward end of the conveyor from for example a hopper 36 which extends transversely across the forward end of the conveyor as shown, or by any other suitable moss delivery system. Moss may be deposited on the conveyor at a rate such that the layer of moss formed on the conveyor and carried to the die is of the desired thickness for forming liners. Alternatively as shown moss may be loosely deposited in bulk and then reduced by leveling drums 40 and 41.
After the moulding stage unused moss 25 between formed liners is carried away and falls from the end of the conveyor to be recycled. Unused moss may fall to trough 45 extending across the end of the conveyor as shown particularly in
We have found suitable materials for forming the conveyor belt to be mock leno fabrics made from spun nylon thread, but the belt may be formed of any suitably flexible and deformable material, which will resiliently return to its original flat form after each pressing, preferably without creasing. The belt material should also be sufficiently tough and durable to withstand the regular deformation of the moulding stage. Preferably the nature of the belt material is also such that when it is deformed to conform to the interior shape of the mould cavity it will stretch to still provide a smooth surface against which the moss is pressed, substantially without wrinkles or folds which would form an impression in the formed moss liner, which may constitute lines of weakness in the product.
The tensioners 35 or equivalent should maintain tension in the conveyor belt so that the belt will automatically spring from the cavity mould 27 as the plunger die part 26 withdraws, to lift the product from the mould, but also so as to allow sufficient “give” in the continuous belt that the belt can be pressed into the mould on each operation without tearing of the belt.
Referring in particular to
The moulding stage may comprise a single plunger and cavity die pair, or alternatively for higher production a number of adjacent plunger and cavity die pairs across the conveyor which operate to produce a multiple number of products at each operation and step of the conveyor. For production flexibility, in a most preferred form the plunger and cavity die parts 26 and 27 are removable so that for example in a machine arranged to form three basket liners simultaneously on each operation of the moulding stage and step of the conveyor, the three plunger die parts 26 and cavity die parts 27 may be removed and replaced with a single longer plunger die part which is carried across the conveyor by the three spaced rams 32 and operates into a single longer transverse cavity die part 27, for forming hayrack liners for example.
The method and apparatus of the invention may also be used for forming sphagnum moss wreaths. Referring to FIGS. 21 to 23 a wreath liner 210 is typically placed within a donut shaped wire frame 221, and filled with soil as shown in
FIGS. 25 to 28 show how a wreath moss liner may be formed by the method of the invention. A cavity die part 27 (carried on bed 30 in
In a preferred form a raised central portion 61 is provided beneath the belt 50 on the mould part 27 as shown, which is preferably formed of a compressible material such as a foam material for example. As shown in
Advantages of the method of the invention include that sphagnum moss liners may be formed without gaps at joins as occur when liners are manufactured as flat blanks which are subsequently folded to shape for use, and in addition the three dimensional shaped liner is immediately recognizable to consumers as a planter liner. Use of the liner requires only unwrapping of the liner (where the product has been packaged for sale) placing it in a wire basket or hayrack or similar and rewetting, and not the more complicated steps of wetting a moss blank to reconstitute it sufficiently to enable it to be folded to shape, but not so much as to
remove all structural integrity of the blank so that it breaks or falls apart on folding, and folding the blank to shape and fitting it within the wire basket
The foregoing describes the invention including preferred forms thereof. Alterations and modifications as will be obvious to those skied in the art are intended to be incorporated within the scope hereof as defined in the accompanying claims.
Number | Date | Country | Kind |
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515579 | Mar 2002 | NZ | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/NZ03/00054 | 3/31/2003 | WO | 10/12/2005 |