Biodegradable Bag

Abstract

The present invention provides a bag made of a non-woven biodegradable material comprising a body portion having at least one side wall and a bottom joined together to define a storage space therebetween and an opening at the top of the body portion, wherein the bag is biodegradable and non-toxic to the environment

We claim: 
     
         1 . A bag made of a non-woven biodegradable polylactide based material comprising a body portion having at least one side wall and a bottom joined together to define a storage space therebetween and an opening at the top of the body portion, wherein the material contains polylactic acid, polyethylene glycol and a chain extender such that the bag is biodegradable and biodegraded products are non-toxic to the environment. 
     
     
         2 . The bag of  claim 1 , wherein the bag is suitable for use as a shopping bag. 
     
     
         3 . The bag of  claim 1 , further comprising a pair of handles, wherein the pair of handles are attached to a top of the body portion at their ends. 
     
     
         4 . The bag of  claim 1 , further comprising at least one strap member. 
     
     
         5 . The bag of  claim 4 , wherein the strap member is attached at or near the top of the body portion and extends across the opening of the body portion of the bag. 
     
     
         6 . The bag of  claim 4 , where the strap member is permanently secured at a first end to a first side of the body portion, the body portion having a fastening member to releasably secure a second end of the strap member to a second opposing side of the body portion. 
     
     
         7 . The bag of  claim 1 , further comprising a pair of apertures provided at or near the top of the body portion for receiving a prong member therethrough to hold the bag in an open state. 
     
     
         8 . The bag of  claim 1 , wherein the biodegradable non-woven material comprises one or more of the following polymers: polylactic acid, polyethylene glycol, chain extender Joncryl—ADR 4370. 
     
     
         9 . The bag of  claim 8 , wherein the material composition of the biodegradable non-woven material is 91-94% polylactic acid, 5-8% polyethylene glycol and 1% chain extender. 
     
     
         10 . The bag of  claim 8 , wherein the biodegradable non-woven material has a weight-average molecular weight ratio above 160000, a dispersion coefficient ≦1.5, a melt index between 20-30 and a water content ≦0.5%. 
     
     
         11 . A method of manufacturing a bag made of a non-woven biodegradable polylactide based material comprising a body portion having at least one side wall and a bottom joined together to define a storage space therebetween and an opening at the top of the body portion, wherein the material contains polylactic acid, polyethylene glycol and a chain extender such that the bag is biodegradable and biodegraded products are non-toxic to the environment, the method comprising the following steps:
 preparing a biodegradable non-woven material mixture;   drying the material to remove residual moisture;   extruding a polylactide (PLA) slicing;   heat melting the extruded PLA slicing;   purifying the melted PLA resin;   spinning the material;   cooling and retracting the material;   needling the material onto a roll; and   forming the bag from the roll of material.   
     
     
         12 . The method of  claim 12 , wherein the material has a weight-average molecular weight ratio above 160000, a dispersion coefficient ≦1.5, a melt index between 20-30 and a water content ≦0.5%. 
     
     
         13 . The method of  claim 12 , wherein the material is vacuum dried at 80-90° C. such that a moisture content of the PLA slicing is less than 200 PPM. 
     
     
         14 . The method of  claim 12 , wherein the extruded PLA slicing is heat melted using a heat screw extruder. 
     
     
         15 . The method of  claim 12 , wherein the melted PLA material is filtered prior to the spinning process using a high viscosity fondant proportional pump to squeeze out the impurities by rotation.