Non-extractable and fiber-free food oil removing film and production method thereof

Abstract

Non-extractable and fiber-free food oil removing film is a flexible with numerous open-cell of microporous structure used for removing oils from cooked food. The said plastic film is made from a mixture of polypropylene polymer, specific carbon atom olefin fillers and nucleating agent. The mixture is plasticized and formed into a tubular film substrate by a tubular blown film extruder, then following biaxial stretching by a specific isostatic pressurized hot water technique forming numerous of smooth, uniform, lipophilic, microporous structure that absorb and retain any kinds of oils from cooked foods. The film is applied in various forms varying to its applications such as sheet, perforated rolls, or laminated on other functional substrates to from a novel food packaging by lamination methods.

Claims

1. A non-extractable and fiber-free food oil removing film which is a flexible film with numerous open-cells of a microporous structure used for removing oils from cooked food, and obtained from a mixture comprising: a. an isotactic polypropylene polymer in a concentration of 65-75% by weight; b. an olefin filler with a carbon atom number in the range of C29 to C200 in a concentration of 25-35% by weight; and c. a nucleating agent in a concentration of 100 to 2,500 parts per million (ppm), wherein said nucleating agent is selected from the group consisting of sorbitol derivatives, benzenetriamide derivatives and a combination thereof.

2. The non-extractable and fiber-free food oil removing film according to claim 1 wherein said isotactic polypropylene polymer has a melt flow rate in the range of 0.1 to 5.0 grams per 10 minutes.

3. The non-extractable and fiber-free food oil removing film according to claim 1 wherein said film is in the form of a sheet, a perforated roll, a laminated multilayer film, or any combinations thereof.

4. A method for producing the non-extractable and fiber-free food oil removing film of claim 1, comprising: a. plasticizing the mixture and forming into a tubular blown film substrate with a transparent, finely dispersed heterophasic structure by a tubular blown film extruder; and b. simultaneously biaxial stretching the substrate to generate a processed film by a specific isostatic pressurized hot water stretching unit which is contained hot water in the said unit.

5. The method for producing the non-extractable and fiber-free food oil removing film according to claim 4 wherein the hot water has the temperature in the range of 50 to 100 degrees Celsius.

6. The method for producing the non-extractable and fiber-free food oil removing film according to claim 4 wherein the biaxial stretching has drawing percentage of machine direction in the range of 150% to 500%.

7. The method for producing the non-extractable and fiber-free food oil removing film according to claim 4 wherein the biaxial stretching has drawing percentage of transverse direction in the range of 150% to 500%.

8. The method for producing the non-extractable and fiber-free food oil removing film according to claim 4 wherein the biaxial stretching has a ratio of the drawing percentage of transverse direction to the drawing percentage of machine direction in the range of 0.7 to 1.2 for all film applications and forms.

9. The method for producing the non-extractable and fiber-free food oil removing film according to claim 4 wherein the biaxial stretching has the ratio of the drawing percentage of transverse direction to the drawing percentage of machine direction in the range of 1.0 to 1.2 when the film is in the form of a perforated roll.

10. The method for producing the non-extractable and fiber-free food oil removing film according to claim 4 wherein the processed film has a pore volume after the biaxial stretching in the range of 30% to 60% of the total film volume.

11. The method for producing the non-extractable and fiber-free food oil removing film according to claim 4 further comprising: laminating the processed film to a functional substrates wherein a bonding area between the processed film and the functional substrate is covered in the range of 1% to 40% of the interface.

12. The method for producing the non-extractable and fiber-free food oil removing film according to claim 11 wherein laminating the processed film to the functional substrate by a process selected from the group consisting of melt-laminating, adhesive laminating, and a combination thereof.

13. The method for producing the non-extractable and fiber-free food oil removing film according to claim 11 wherein the laminating process is provided in an arranged discrete pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) Non-extractable and fiber-free food oil removing film is a flexible with numerous open-cell of microporous structure used for removing oils from cooked food that are made from a mixture comprising: a. Isotactic polypropylene polymers in concentration of 65-75% by weight with a melt flow rate in the range of 0.1-5.0 grams per 10 minutes b. Olefin fillers with carbon atom number in the range of C29 to C200 in concentration of 25-35% by weight c. Nucleating agents in concentration of 100 to 2,500 part per millions (ppm), the said nucleating agent can be selected from sorbitol derivatives or benzenetriamide derivatives or combination thereof.

(2) The non-extractable and fiber-free food oil removing film can be applied in the selected from sheet or perforated roll or laminated multilayer film or combination thereof.

(3) A production method of the non-extractable and fiber-free oil removing film comprises the following steps: a. Plasticizing the mixture and forming into a tubular blown film substrate with a transparent, finely dispersed heterophasic structure by a tubular blown film extruder; and b. Simultaneously biaxial stretching the substrate to generate the processed film by a specific isostatic pressurized hot water stretching unit which is contained pressurized hot water with temperature in the range of 50 to 100 degree Celsius in tubular blown film bubble.

(4) Volume of the pressurized hot water stretch or draw the said film in transverse direction and expand the plastic film bubble diameter which determine the film thickness, lay flat width and transverse direction drawing percentage. While, a serial of nip rollers which each set of the nip rolls rotate forward faster and faster that determines the film thickness and machine direction drawing percentage. The processed film may be a single layer or multilayer tubular blown film substrate varying to its final applications.

(5) After the process of biaxial stretching, the film appearance becomes an opaque, smooth film with numerous open-cell of microporous structure dispersing thoroughly all film structure. To achieve high oil absorption performance, the biaxial stretching or drawing percentage in both directions, machine direction and transverse direction, is in the range of 150% to 500%. The processed film is provided pore volume after biaxial stretching in the range of 30% to 60% of the total film volume. The variation of drawing percentage in both directions affects the final product characteristics and performances.

(6) A ratio of the drawing percentage of transverse direction per the drawing percentage of machine direction is in the range of 0.7 to 1.2 for all film applications and forms such as sheet, perforated roll or laminated multilayer film The said ratio is preferably in the range of 1.0 to 1.2 when the film is applied in perforated roll form application to ensure inducing easy and smooth tear along the transverse direction perforated line.

(7) For another application, form-fill-seal (FFS) food packaging, the film can be laminated or bonded on other functional substrates by lamination methods which bonding area is in the range of 1% to 40%. The lamination methods can be selected from melt-lamination or adhesive lamination or combination thereof. The said lamination method is provided in arranged discrete pattern to form a novel food packaging with oil absorbing liner. Excessive oil from fried snacks will be absorbed and retained inside, that keep the fried food or snack crispier and heathier.