Abstract:
A material in the form of a sheet for enveloping a bale of agricultural material is coated with or contains a preservative in order to prevent spoilage of wrapped bales of agricultural material by aerobic organisms.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention concerns an enveloping material for the enveloping of a bale of agricultural material.  
         BACKGROUND OF THE INVENTION  
         [0002]    It is known practice in the state of the art to envelop bales of agricultural products such as grass (hay) and straw with an air-tight and water-tight foil. Such wrapped bales may contain silage, that is, products with more than 50% moisture. The foil generates an anaerobic environment in the bale in which certain organisms which would lead to spoilage of the silage, such as in particular, aerobic fungi and bacteria, cannot survive. In this way, the foil prevents an undesirable spoilage of the products.  
           [0003]    It is known practice from WO 90/07284 A and WO 92/17071 A to mix urea (a preservative) with agricultural products with relatively high moisture, to bale these and finally to wrap these. A chemical reaction develops in the bale that should lead to an increased protein and amylum content.  
           [0004]    Furthermore, it may be desirable for the reduction of losses in the harvest to wrap hay of lower moisture content with foil. Here it should be noted that only completely dried hay with a moisture of approximately 12% is wrapped since it is otherwise spoiled by aerobic fungi, bacteria or thermophile actinomycetin. Hay can be dried to such a low moisture content only with a high degree of loss. In wrapped bales a drying to these low levels of moisture is not possible even with foils that permit passage of water. With moisture levels between 12% and 35% the application of preservatives would be possible, however, not with moisture levels above 35%, since these materials are not sufficiently effective at such high levels of moisture. For example, in DE 32 32 746 A, a baler is described in which preservatives are added to the harvested crop depending on its measured moisture level.  
           [0005]    With wrapped silage bales, it is seen as problematical that undesirable holes in the envelope can destroy the anaerobic environment which can result in spoilage of the agricultural material by the aforementioned organisms. The proportion of the material spoiled depends on the size of the hole, the density of the bale and the depth to which the wind can penetrate under the envelope. The proportion of the material spoiled can affect a small volume or the entire bale, if it is too loose or too dry.  
           [0006]    The problem underlying the invention is seen in the need to prevent spoilage of wrapped bales of agricultural material by aerobic organisms or at least to reduce the spoilage.  
         SUMMARY OF THE INVENTION  
         [0007]    According to the present invention, there is provided an improved bale wrapping material.  
           [0008]    An object of the invention is to envelop bales with an enveloping material consisting of a carrier material to which a preservative has been applied. The preservative is contained, for example, in a layer applied to the carrier material and/or in the enveloping material, which is sufficiently porous. With porous enveloping material the pores may be closed initially but already contain the preservative. The stretching of the enveloping material during the wrapping process opens the pores and releases the preservative. The preservative may be volatile so that it penetrates into the volume of the bale after the bale is wrapped and combats the undesirable organisms there. It is present in increased concentration at the surface that is particularly endangered by the penetration of airborne oxygen. A coating can be applied to the outside of the enveloping material to prevent the escape of the preservative.  
           [0009]    In this way the preservative prevents spoilage of the agricultural material in the case of silage (products with more than 50% moisture) in the bale, if air reaches the bale through undesirable holes or tears in the enveloping material. The anaerobic organisms that otherwise lead to spoilage of the products are killed by the preservative. The enveloping material according to the invention protects the agricultural material from airborne oxygen, retains the preservative in the interior of the envelope and prevents an undesirable spoilage of the agricultural material, in case that holes or tears occur in the enveloping material. With the use of the enveloping material according to the invention it is also conceivable that hay bales with material having a moisture content of more or less than 35% could be wrapped.  
           [0010]    The invention makes it possible to omit the addition of preservatives into the agricultural material. Thereby a saving is generated by the omission of arrangement for the metering of the preservative and measurement arrangements for the determination of the quantity required at that time. It is also conceivable that preservatives be metered into the agricultural material for bales of silage as well as hay.  
           [0011]    The preservatives are, in particular, those chemicals used in the state of the art as preservatives for agricultural products, such as propionic acid, lactic acid, acetic acid, formaldehyde, ammonia compounds, urea, certain bacteria and fermentation products.  
           [0012]    The preservative is preferably applied to the inner side of the carrier material facing the bale. In addition, or as an alternative, it can also be located on the outside of the carrier material.  
           [0013]    As a rule, the invention is applied to bale wrapping arrangements or balers in which bales of agricultural material are wrapped or enclosed in enclosure materials according to the invention. The preservative may already be located on the enclosure material, that is, rolls of the enclosure material are used to which the preservative has been applied. It is also conceivable that the preservative be applied to the enclosure material only during the enclosure of the bale which can be applied as a liquid by spray nozzles or by means of immersion in a bath.  
           [0014]    These and other objects will become apparent from a reading of the ensuing description together with the appended drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 shows a left side elevational view of a combined round baler and bale wrapping machine with which wrapping material, made according to the present invention, may be used.  
         [0016]    [0016]FIG. 2 shows a cross section through the enveloping material.  
         [0017]    [0017]FIG. 3 shows an enlarged section of another embodiment of the combined baler and bale wrapping machine. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0018]    [0018]FIG. 1 shows an agricultural machine  10 . In this embodiment, the agricultural machine  10  is configured as a combination of a baler  14 , in particular a rotobaler, and an enveloping arrangement  16 , that are supported together on the ground by a chassis  18 . A towbar  20  is connected to the front of the baler  14 , and in turn, is connected to an agricultural tractor, not shown. The baler  14  and the enveloping arrangement  16  are supported on the chassis  18  by means of several struts of which a forward strut  22  and a rear strut  24  are noted. These struts  22  and  24  are located at both sides of the baler  14 .  
         [0019]    The enveloping arrangement  16  is located at the rear end of the chassis  18  and is provided with two arms  26  that can rotate together about a vertical axis and each of whose vertical end regions rotatably support a supply roll  28  of enveloping material  40  (see FIG. 2). This enveloping material  40  is wrapped around a cylindrical bale, not shown, as soon as the bale is delivered by the baler  14  and is accepted by a rotary wrapping table  30 . The agricultural machine  10 , as described up to this point, is described in detail in the German patent application 100 44 166, whose disclosure is expressly incorporated herein by reference.  
         [0020]    As an alternative, the agricultural machine  10  can be configured as an independent wrapping machine or as a rotobaler, in or on which, a roll  28  with enveloping material can be applied.  
         [0021]    [0021]FIG. 2 shows a cross section through the enveloping material  40  that is wrapped upon the roll  28 . The enveloping material  40  includes a carrier material  42  that consists of a water tight and air tight stretch foil and a coating  44  that contains a preservative. The carrier material  42  is also impenetrable to the preservative. The preservative is fastened to the carrier material  42  by appropriate adhesives contained in the coating  44 . The roll  28  with the enveloping material  40  is inserted into the enveloping arrangement  16  in such a way that the coating  44  with the preservative is brought into contact with a cylindrical bale produced by the baler  14 . The carrier material  42  generates an anaerobic environment in the bale. The preservative is volatile and penetrates the volume of the bale. Thereby spoilage of the agricultural material in the bale by aerobic organisms is prevented. Due to the increased concentration of the preservative in the outer region of the bale, spoilage is prevented even if a hole or a tear develops in the envelope.  
         [0022]    [0022]FIG. 3 shows a section of an agricultural machine which generally coincides with that shown in FIG. 1. While an enveloping material  40  that is in itself porous, is wrapped onto the roll  28 , an arrangement is provided for the impregnating of the carrier material  42  with a preservative. This arrangement includes a roll  46  opposite to which a sponge  48  is arranged that is impregnated with a preservative from an appropriate reservoir. The carrier material  42  is drawn between the roll  46  and the sponge  48  so that the preservative is applied by the sponge  48 . On the surface located opposite the sponge  48  the carrier material  42  is provided with a thin layer  43  that is not permeable to the preservative, and prevents it from dissipating to the outside. In place of the sponge  48 , spray nozzles could also be used.  
         [0023]    Downstream of the sponge  48 , the enveloping material  44  that is now ready for application, is conducted between two rolls  50  and  52 , the roll  52  here being shown spring loaded against the roll  50 , and is used for the enveloping of the bale with the side of the wrapping material which is impregnated with preservative being in contact with the bale. If necessary, the rolls  50  and  52  can be omitted. The arrangement shown in FIG. 3 is applied to each of the arms  26  of the agricultural machine  10 , that is, it is present in two locations. After the bale is wrapped, the preservative evaporates at least partially and penetrates the volume of the bale. Undesirable organisms that lead to spoilage of the material in the bale are effectively combated in this way. The concentration of the preservative is greatest at the surface of the bale and that is where holes or tears in the enveloping material  40  are most likely to occur. Obviously, it would also be conceivable that, with the arrangement shown in FIG. 3, such enveloping material could also be wrapped around rolls and used in the machine illustrated in FIG. 1.  
         [0024]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.