Preparation method for multi-layer co-extrusion two-way stretched high-barrier plastic casing

Abstract

The invention discloses a preparation method for a multi-layer co-extrusion two-way stretched high-barrier plastic casing. The preparation method comprises the following steps of: respectively adding raw materials of each layer into an extruder for each layer for melting and plasticizing, wherein the multi-layer co-extrusion two-way stretched high-barrier plastic casing is formed by co-extruding five layers of raw materials; extruding the raw materials by a multi-layer stacked type round mold to form a multi-layer mold blank; slightly blowing and stretching the mold blank, and then immediately and rapidly cooling and molding the mold blank by using cooling water of 5-15 DEG C into a first pipe film; heating the first pipe film in a hot water tank or an infrared heating system to a proper temperature; aerating compressed air to ensure that the mold blank is transversely stretched for a multiplying power of 3 to 5 times and longitudinally stretched for a multiplying power of 2.5 to 3 times to form a second pipe film; putting the second pipe film in an infrared heating barrel for sizing; and rolling a finished product after cooling the second pipe film to a required fold diameter and shrinkage rate by using a vane. Plastic casings prepared by the preparation method have the characteristics of high barrier, high water retention and environmental protection.

Description

technical field

[0001] The invention relates to a method for preparing multi-layer co-extruded biaxially stretched high-barrier plastic casings. The high-barrier plastic casings are mainly used for freezing, fresh-keeping and cooking packaging of low-temperature meat products or other foods, and are used for automatic punching and ligation machines or manual Packaging of low-temperature meat products such as sandwiches, sandwiches, and round hams produced by clocking in. Background technique

[0002] At present, the plastic casings used to make ham sausages and sandwich square legs on the market include polyvinylidene chloride (PVDC) high-temperature cooking plastic casings, polyamide (PA) and polyolefin (PO) and other resins. Multi-layer co-extrusion Two-way stretch low-temperature cooking plastic casings. Inadequacies of existing packaging: a. Although the barrier properties of PVDC plastic casings are very suitable for packaging applications, there are many defects in pr...

Examples

Embodiment 1

[0010] The preparation method of the multi-layer co-extruded biaxially stretched high-barrier plastic casing comprises the following steps:

[0011] Multi-layer co-extruded biaxially stretched high-barrier plastic casings are five-layer raw materials co-extruded, the first layer, the inner layer is polyamide and polyolefin, with a weight percentage of 15%, the second layer, the adhesive layer is polyolefin, Blend of ionomer and adhesive resin, 10% by weight, the third, barrier layer is ethylene-vinyl alcohol copolymer, 5% by weight, and the fourth, adhesive layer is polyolefin , ionomer and adhesive resin blend, the percentage by weight is 10%, the fifth layer, that is, the outer layer is polyamide, and the percentage by weight is 60%; the above-mentioned layers of raw materials are respectively added to each layer of extruder for melting Melting and plasticizing, the temperature is 210°C for polyamide, 170°C for ethylene-vinyl alcohol copolymer, 160°C for polyolefin, 160°C fo...

Embodiment 2

[0013] The preparation method of the multi-layer co-extruded biaxially stretched high-barrier plastic casing comprises the following steps:

[0014] Multi-layer co-extruded biaxially stretched high-barrier plastic casings are five-layer raw materials co-extruded, the first layer, the inner layer is polyamide and ionomer, the weight percentage is 15%, the second layer, the adhesive layer is polyamide Olefins, ionomers and pure adhesive resins, 15% by weight, the third, barrier layer is ethylene-vinyl alcohol copolymer, 10% by weight, and the fourth, adhesive layer is polyolefin , ionomer and pure adhesive resin, the weight percentage is 15%, the fifth layer, that is, the outer layer is polyamide, and the weight percentage is 45%; the raw materials of the above layers are added to each layer of extruder for melting and molding The processing temperature is 230°C for polyamide, 200°C for ethylene-vinyl alcohol copolymer, 190°C for polyolefin, and 195°C for ionomer and adhesive re...

Embodiment 3

[0016] The preparation method of the multi-layer co-extruded biaxially stretched high-barrier plastic casing comprises the following steps:

[0017] Multi-layer co-extruded biaxially stretched high-barrier plastic casing is a five-layer raw material co-extruded, the first layer, the inner layer is polyamide and ionomer, the weight percentage is 30%, the second layer, the adhesive layer is polyamide Olefins, ionomers and pure adhesive resins, 15% by weight, the third, barrier layer is ethylene-vinyl alcohol copolymer, 10% by weight, and the fourth, adhesive layer is polyolefin , ionomer and adhesive resin blend, the percentage by weight is 15%, the fifth layer, that is, the outer layer is polyamide, and the percentage by weight is 30%; the above-mentioned layers of raw materials are respectively added to each layer of extruder for melting Melting and plasticizing, the temperature is 250°C for polyamide, 225°C for ethylene-vinyl alcohol copolymer, 220°C for polyolefin, 230°C for...

technical field

[0001] The invention relates to a method for preparing multi-layer co-extruded biaxially stretched high-barrier plastic casings. The high-barrier plastic casings are mainly used for freezing, fresh-keeping and cooking packaging of low-temperature meat products or other foods, and are used for automatic punching and ligation machines or manual Packaging of low-temperature meat products such as sandwiches, sandwiches, and round hams produced by clocking in. Background technique

[0002] At present, the plastic casings used to make ham sausages and sandwich square legs on the market include polyvinylidene chloride (PVDC) high-temperature cooking plastic casings, polyamide (PA) and polyolefin (PO) and other resins. Multi-layer co-extrusion Two-way stretch low-temperature cooking plastic casings. Inadequacies of existing packaging: a. Although the barrier properties of PVDC plastic casings are very suitable for packaging applications, there are many defects in pr...

Examples

Embodiment 1

[0010] The preparation method of the multi-layer co-extruded biaxially stretched high-barrier plastic casing comprises the following steps:

[0011] Multi-layer co-extruded biaxially stretched high-barrier plastic casings are five-layer raw materials co-extruded, the first layer, the inner layer is polyamide and polyolefin, with a weight percentage of 15%, the second layer, the adhesive layer is polyolefin, Blend of ionomer and adhesive resin, 10% by weight, the third, barrier layer is ethylene-vinyl alcohol copolymer, 5% by weight, and the fourth, adhesive layer is polyolefin , ionomer and adhesive resin blend, the percentage by weight is 10%, the fifth layer, that is, the outer layer is polyamide, and the percentage by weight is 60%; the above-mentioned layers of raw materials are respectively added to each layer of extruder for melting Melting and plasticizing, the temperature is 210°C for polyamide, 170°C for ethylene-vinyl alcohol copolymer, 160°C for polyolefin, 160°C fo...

Embodiment 2

[0013] The preparation method of the multi-layer co-extruded biaxially stretched high-barrier plastic casing comprises the following steps:

[0014] Multi-layer co-extruded biaxially stretched high-barrier plastic casings are five-layer raw materials co-extruded, the first layer, the inner layer is polyamide and ionomer, the weight percentage is 15%, the second layer, the adhesive layer is polyamide Olefins, ionomers and pure adhesive resins, 15% by weight, the third, barrier layer is ethylene-vinyl alcohol copolymer, 10% by weight, and the fourth, adhesive layer is polyolefin , ionomer and pure adhesive resin, the weight percentage is 15%, the fifth layer, that is, the outer layer is polyamide, and the weight percentage is 45%; the raw materials of the above layers are added to each layer of extruder for melting and molding The processing temperature is 230°C for polyamide, 200°C for ethylene-vinyl alcohol copolymer, 190°C for polyolefin, and 195°C for ionomer and adhesive re...

Embodiment 3

[0016] The preparation method of the multi-layer co-extruded biaxially stretched high-barrier plastic casing comprises the following steps:

[0017] Multi-layer co-extruded biaxially stretched high-barrier plastic casing is a five-layer raw material co-extruded, the first layer, the inner layer is polyamide and ionomer, the weight percentage is 30%, the second layer, the adhesive layer is polyamide Olefins, ionomers and pure adhesive resins, 15% by weight, the third, barrier layer is ethylene-vinyl alcohol copolymer, 10% by weight, and the fourth, adhesive layer is polyolefin , ionomer and adhesive resin blend, the percentage by weight is 15%, the fifth layer, that is, the outer layer is polyamide, and the percentage by weight is 30%; the above-mentioned layers of raw materials are respectively added to each layer of extruder for melting Melting and plasticizing, the temperature is 250°C for polyamide, 225°C for ethylene-vinyl alcohol copolymer, 220°C for polyolefin, 230°C for...

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