Patent Application
20200115110
This application claims priority to Chinese Patent Application Ser. No. CN201811175132.2 filed on 10 Oct. 2018.
The present invention relates to a packaging bag, in particular to a fully-naturally-degradable packaging bag.
A heat-insulating environmentally-friendly packaging bag for express delivery, is made from a fully-biological-based new plastic material by various molding techniques, avoiding the traditional use of non-environmental materials such as wood-based and petroleum-based materials, popularization. And use of this application can effectively reduce the consumption of wood and petrochemical materials, prevent the imbalance of natural ecosystem and the pollution and destruction of chemical materials to the environment.
Polylactic acid (PLA) is a new biodegradable material, made from the starch raw material extracted from the renewable plant resources (such as corn). The starch raw material is made into a lactic acid by the way of fermentation, and then is converted to polylactic acid by the way of chemical synthesis. It has an excellent biodegradability, and can be completely degraded by microorganisms in nature after use, finally produces carbon dioxide and water, which do not pollute the environment, and it is very benefit to protect the environment, known as an environmentally friendly material. Publication number CN105416797B disclosed a biodegradation packaging bag for express delivery, which is made of a composite coating, wherein the composite coating comprises a first layer, a third layer and a second layer between the first layer and the third layer. The first layer, the third layer and the second layer are respectively made of coating material A or coating material B; the coating material A, by weight percentage, is composed of the following components: 95.5% of polylactic acid, 3% of degradable color masterbatch, 1.5% of tackifier; the coating material B, by weight percentage, is composed of the following components: 95% of polyadipate/butylene terephthalate, 3.5% of degradable color masterbatch, 1.5% of a tackifier. The invention further disclosed a three-layer co-extrusion-blown molding technology of the biodegradation packaging bag for express delivery. According to the invention, the raw material is easy to obtain with low production cost, is convenient to process, having an excellent processability, mechanical property and low-temperature resisting tenacity, is suitable for the packaging industry for express delivery, and it is biodegradable under the compost condition, to solve the problem about environmental pollution caused by consumption of a disposable express delivery packaging bag.
At present, degradable material is mainly made in the form of coated bags. The shaping auxiliary materials such as tackifiers, compatibilizers are unavoidably added in manufacturing. In order to seal the packaging bag, stickers, zippers and self-sealing strips are needed to be added, however, these auxiliary materials are difficult to degrade, or high in cost. The stickers, zippers and self-sealing strips left on the bags are always not easily degradable, could not achieve real full degradation.
The technical problem to be solved by the present invention is to provide a fully-degradable heat-insulating environmentally-friendly packaging bag for express delivery for above prior art, especially a packaging bag with degradable zippers, which simplifies the raw material, and achieves the rapid full degradation of the packaging bag.
The technical solution adopted by the present invention is: a fully-degradable heat-insulating environmentally-friendly packaging bag for express delivery, comprising a bag body, wherein the bag body has double fabric layers, including an inner layer of hot-rolled non-woven fabric, an outer layer of coated non-woven fabric, and a sandwich layer wherein the sandwich layer is filled with heat-insulating fibers. The bag body is using PLA biodegradable plastic material as base material, and the bag body is produced by spinning PLA, manufacturing thin non-woven fabric, coating non-woven fabric, printing, forming a bag, and filling the fibers.
The packaging bag for express delivery is produced by following processes:
(1) spinning PLA, wherein spinning-grade PLA slices are used as raw materials to prepare PLA fibers, including melt spinning using a screw-type spinning machine, and the melting point of PLA is 175° C., and a spinning box is using a heating medium with a low boiling point so that it is suitable for PLA, comprising following detailed steps: drying the raw materials until that a water content is less than 30 ppm, setting a screw pre-melting temperature to be 195˜210° C., setting a screw outlet temperature to be 200˜215° C., setting a spinning head temperature to be 200˜210° C., cooling, winding, cutting into sections, and then obtaining PLA short fibers;
(2) manufacturing thin non-woven fabric, wherein PLA short fibers are used as raw materials, and a hot-rolled non-woven fabric equipment is used, including following steps: carding PLA fibers, feeding fibers pneumatically, spreading fibers using a vibrating screen, hot rolling with a couple of rollers, and then forming non-woven fabric;
(3) coating non-woven fabric, wherein the outer surface of some thin non-woven fabric is coated, and PBAT material is used for the coating, including placing pure PBAT slices into a hopper of a coating machine, into a extruding screw and then forward to a coating die according to designated levels of temperatures, wherein the temperatures of the screw and the die are controlled by a PLC controller of the coating machine, so that temperature control, die extrusion volume and non-woven fabric speed match with one another, wherein the thickness of the coating is effectively controlled to be 20˜60 g/square meter, preferable 40 g/square meter, and then cooling by a cooling drum;
(4) printing, including printing on the coated layer of the non-woven fabric;
(5) forming a bag, so that a bag body with a filling hole on its side is formed;
(6) filling fibers, wherein PLA fibers are used as heat-insulating fibers and are filled into the sandwich layer of the bag body, including making PLA fibers fluffy, automatically suctioning the fibers into a filling machine, aligning the filling hole of the bag body with a filling outlet of the filling machine, quantitatively filling the fibers, sealing the filling hole, and obtaining a finished product of a heat-insulating bag.
The bag body is being sealed by a zipper, the zipper's chain body and slider are made of composite materials of PLA and PBAT. In order to achieve full-degradation, as a part of the bag body, the zipper is required to be degradable, but the experiment finds that, using pure PLA can not match the production mode of zipper and is difficult to be applied in zipper production, the present application uses PBAT to modify PLA, wherein the chain body of the zipper is made of a mixture of 20% PLA+80% PBAT, the temperatures of extruder screw for the zipper are set to be 125° C. (feeding inlet), 135° C., 140° C., 145° C., 150° C. (discharge outlet). The slider of the zipper is made of a mixture of 50% PLA+50% PBAT or a mixture of 50% PLA+50% PBS, it is produced by injection molding using an injection molding machine, and the temperatures of screw are set to be 130° C. (feeding inlet), 150° C., 160° C., 170° C., 180° C. (nozzle), and a draft angle of an injection mould is so designed as to be greater than 5 degrees because of a high viscosity of material. Otherwise, it might be difficult to demould.
The above chain body of the zipper achieves a hardness required for use, the hardness of the slider is larger than that of the chain body, the hardness of the slider in present application achieves a hardness similar to PE and PP.
Preferably, in the step (1), the PLA short fibers are 4D fibers as heat-insulating material. This material is especially outstanding in the aspect of fluffy degree, and has a good heat-insulating effect.
Preferably, in the step (3), the screw is provided with six levels of temperatures, which are 160° C., 190° C., 200° C., 223° C., 223° C., 223° C. in sequence, and the temperature of die is set to be 223° C.
Because PBAT has a strong viscosity, a normal coating machine is likely to have a phenomenon that the coating is being bonded to the cooling drum. The cooling drum in our step (3) is equipped with a contact layer of polytetrafluoroethylene on its surface, the surface of the coating contacts the contact layer of polytetrafluoroethylene of the cooling drum to reduce the bonding between the coating and cooling drum, meanwhile, in combination with the adjustment of the extruder screw temperature of the coating machine, it effectively avoids the occurrence of the coating surface being bonded to the cooling drum.
As to the bag body being sealed by a zipper, the bag body is formed by a non-woven zipper bag making machine, with following steps: feeding double layers of non-woven fabric, automatically welding a zipper on both sides by ultrasonic, folding, automatically installing a slider of zipper, heating by ultrasonic, and cutting into bags, wherein a filling hole is left on a side of a bag.
Compared with the prior art, the advantages of present invention are:
1) The heat-insulating environmentally-friendly packaging bag for express delivery in present application is using biodegradable plasticity materials such as PLA as base materials, and is produced by spinning PLA, manufacturing thin non-woven fabrics, coating non-woven fabric, printing, forming a bag, and filling the fibers (PLA fibers); PLA is obtained by extracting and polymerizing the annual grain, the material character determines a sustainable regeneration and return to nature through microbial degradation in water.
2) The heat-insulating environmentally-friendly packaging bag for express delivery, in order to ensure high purity of degradable materials, is free of adding any harmful chemicals in manufacture process, which adopts a technique of hot fusion ultrasonic fusion, avoids adding non-degradable auxiliary materials, and achieves a full degradation in real sense.
3) The material itself is sustainably recyclable, the source of raw material is environmentally-friendly.
4) The packaging bag is using PLA short fibers as filling fibers, belonging to a kind of high-voidage fiber material. They are safe and sanitary when being filled in the sandwich layer.
The present invention is further described in detail with reference to the embodiments.
A fully-degradable heat-insulating environmentally-friendly packaging bag for express delivery, comprising a bag body, the bag body has double fabric layers, including an inner layer of hot-rolled non-woven fabric, an outer layer of coated non-woven fabric, and a sandwich layer wherein the sandwich layer is filled with heat-insulating fibers. The bag body is using PLA biodegradable plastic material as base material, and the bag body is being sealed by a zipper, the zipper's chain body and slider are made of composite materials of PLA and PBAT.
The above packaging bag is produced by spinning PLA, manufacturing thin non-woven fabric, coating non-woven fabric, printing, forming a bag, and filling the fibers. The packaging bag is produced by following steps:
(1) spinning PLA, spinning-grade PLA slices are used as raw materials to prepare PLA fibers, including melt spinning using a screw-type spinning machine, wherein the melting point of PLA is 175° C., and a spinning box is using a heating medium with a low boiling point so that it is suitable for PLA, comprising following detailed steps: drying the raw materials until that a water content is less than 30 ppm, setting a screw pre-melting temperature to be 200° C., setting a screw outlet temperature to be 215° C., setting a spinning head temperature to be 200° C., cooling, winding, cutting into sections, and then obtaining PLA short fibers;
(2) manufacturing thin non-woven fabrics, PLA short fibers are used as raw materials and a hot-rolling non-woven fabric equipment is used, including following steps: carding PLA fibers, feeding fibers pneumatically, spreading fibers using a vibrating screen, hot rolling with a couple of rollers, and then forming non-woven fabric;
(3) coating non-woven fabric, the outer surface of some thin non-woven fabric is coated, and PBAT material is used for the coating, including placing pure PBAT slices into a hopper of a coating machine, into a extruding screw and then forward to a coating die according to designated levels of temperatures, wherein the temperatures of the screw and the die are controlled by a PLC controller of the coating machine, the screw is provided with six levels of temperatures, which are 160° C., 190° C., 200° C., 223° C., 223° C., 223° C. in sequence, and the temperature of die is set to be 223° C., the non-woven fabric speed is set to be 50 g/square meter so that the thickness of the coating is effectively controlled to be 40 g/square meter, and then cooling by a cooling drum;
(4) printing: including printing on the coated layer of the non-woven fabric, the coating can not only prevent water permeability of heat-insulating bag but also enhance the artistic effect of surface printing;
(5) forming a bag, so that a bag is formed by a non-woven zipper bag making machine, including following steps: feeding double layers of non-woven fabric, automatically welding a zipper on both sides by ultrasonic, folding, automatically installing a slider of the zipper, heating by ultrasonic, and cutting into bags, wherein a filling hole is left on a side of a bag.
(6) filling fibers, PLA fibers are used as heat-insulating fibers and are filled into the sandwich layer of the bag body, including making PLA fibers fluffy, automatically suctioning the fibers into a filling machine, aligning the filling hole of the bag body with a filling outlet of the filling machine, quantitatively filling the fibers, sealing the filling hole, and obtaining a finished product of a heat-insulating bag.
The above chain body is made of a mixture of 20% PLA+80% PBAT, and the temperatures of extruder screw for the zipper are set to be 125° C. (feeding inlet), 135° C., 140° C., 145° C., 150° C. (discharge outlet). The slider of the zipper is made of a mixture of 50% PLA+50% PBAT or a mixture of 50% PLA+50% PBS, and it is produced by injection molding using an injection molding machine, and the temperatures of screw are set to be 130° C. (feeding inlet), 150° C., 160° C., 170° C., 180° C. (nozzle), and a draft angle of an injection mould is so designed as to be 5 degrees because of a high viscosity of material.
In order to prevent the bonding between the coating surface and the cooling drum, the cooling drum is equipped with a contact layer of polytetrafluoroethylene on its surface, the surface of the coating contacts the contact layer of polytetrafluoroethylene of the cooling drum during cooling.
A fully-degradable heat-insulating environmentally-friendly packaging bag for express delivery is made by spinning PLA, manufacturing thin non-woven fabric, coating non-woven fabric, printing, forming a bag, and filling the fibers. The packaging bag is produced by following steps:
(1) spinning PLA, spinning-grade PLA slices are used as raw materials to prepare PLA fibers, including melt spinning using a screw-type spinning machine, wherein the melting point of PLA is 175° C., and a spinning box is using a heating medium with a low boiling point so that it is suitable for PLA, comprising following detailed steps: drying the raw materials until that a water content is less than 30 ppm, setting a screw pre-melting temperature to be 210° C., setting a screw outlet temperature to be 200° C., setting a spinning head temperature to be 210° C., cooling, winding, cutting into sections, and then obtaining PLA short fibers;
(2) manufacturing thin non-woven fabrics, PLA short fibers are used as raw materials and a hot-rolling non-woven fabric equipment is used, including following steps: carding PLA fibers, feeding fibers pneumatically, spreading fibers using a vibrating screen, hot rolling with a couple of rollers, and then forming non-woven fabric;
(3) coating non-woven fabric, the outer surface of some thin non-woven fabric is coated, and PBAT material is used for the coating, including placing pure PBAT slices into a hopper of a coating machine, into a extruding screw and then forward to a coating die according to designated levels of temperatures, wherein the temperatures of the screw and the die are controlled by a PLC controller of the coating machine, the screw is provided with six levels of temperatures, which are 160° C., 190° C., 200° C., 223° C., 223° C., 223° C. in sequence, and the temperature of die is set to be 223° C., the non-woven fabric speed is set to be 50 g/square meter so that the thickness of the coating is effectively controlled to be 40 g/square meter, and then cooling by a cooling drum;
(4) printing, including printing on the coated layer of the non-woven fabric, the coating can not only prevent water permeability of heat-insulating bag but also enhance the artistic effect of surface printing;
(5) forming a bag, so that a bag is formed by a non-woven zipper bag making machine, including following steps: feeding double layers of non-woven fabric, automatically welding a zipper on both sides by ultrasonic, folding, automatically installing a slider of the zipper, heating by ultrasonic, and cutting into bags, wherein a filling hole is left on a side of a bag.
(6) filling fibers, PLA fibers are used as heat-insulating fibers and are filled into the sandwich layer of the bag body, including making PLA fibers fluffy, automatically suctioning the fibers into a filling machine, aligning the filling hole of the bag body with a filling outlet of the filling machine, quantitatively filling the fibers, sealing the filling hole, and obtaining a finished product of a heat-insulating bag.
The above chain body is made of a mixture of 20% PLA+80% PBAT, and the temperatures of extruder screw for the zipper are set to be 125° C. (feeding inlet), 135° C., 140° C., 145° C., 150° C. (discharge outlet). The slider of the zipper is made of a mixture of 50% PLA+50% PBAT or a mixture of 50% PLA+50% PBS, and it is produced by injection molding using an injection molding machine, and the temperatures of screw are set to be 130° C. (feeding inlet), 150° C., 160° C., 170° C., 180° C. (nozzle), and a draft angle of an injection mould is so designed as to be 5 degrees because of a high viscosity of material.
In order to prevent the bonding between the coating surface and the cooling drum, the cooling drum is equipped with a contact layer of polytetrafluoroethylene on its surface, the surface of the coating contacts the contact layer of polytetrafluoroethylene of the cooling drum during cooling.
Performance test data of Embodiment 1 and 2 are shown in below table
The raw material of present application is very simple, free of addition of any other chemicals. By optimizing the technique design, a fully-degradable packaging bag with a single raw material is obtained in real sense.
Besides above embodiments, the present invention also includes other embodiments, and any technical solution formed by equivalent transformation or equivalent substitution shall fall within the scope of protection of the claims of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201811175132.2 | Oct 2018 | CN | national |
