Process for the manufacture of environmentally friendly papers and compositions therefor
A process for the manufacture of an environmental friendly paper from about 56% to about 80% by weight of inorganic mineral powders, about 43% to 18% by weight of polyethylene, and about 1% to 2% by weight of additives is disclosed. A composition for the manufacture of an environmental friendly paper, comprising about 56% to 80% by weight of inorganic mineral powders, about 43% to 18% by weight of polyethylene, and about 1% to 2% weight by additives is also disclosed.
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The present invention relates to a process for the manufacture of an environmental friendly paper having up to about 80% by weight of inorganic mineral powders. More particularly, the present invention relates to a process for the manufacture of a paper having two dimensional strength by using a combination of at least of one extruder and a forming mould having an ∘-shaped gate. The present invention also relates to a composition for the manufacture of an environmental friendly paper comprising up to about 80% weight of inorganic mineral powders.
BACKGROUND OF THE INVENTIONNumerous synthetic papers have been developed. Papers of single and multiple layers having polypropylene as a main component and inorganic mineral powders as fillers are produced from formulations of conventional plastic films. Papers are coextruded as a single layer or multiple layers during the process, and are formed as a sheet through a forming mould having a direct-line gate. After being stretched in a longitudinal direction, the sheet is laminated by other sheets on its two sides, and then it is stretched in latitudinal direction. The resulting multiple-layered paper has a middle layer which has been stretched in two directions and two surface layers which have only been stretched in one direction. If the sheet which has been stretched in a longitudinal direction is subjected to the stretch in a latitudinal direction, the resulting paper with a single layer or multiple layers possesses two dimensional stretched properties at its surface. Although advantages can be found in the above papers made from polypropylene, they are still inferior to the papers made from pulp. The drawbacks of the papers made from polypropylene include bad foldability, great differences between latitudinal and longitudinal tearing strength, or no tearing ability, etc. In addition, the papers made from polypropylene will not quickly decompose in a natural environment. Furthermore, the production cost of synthetic papers is much higher than that of pulp papers. In view of the above drawbacks, synthetic papers do not fully comply with the needs of consumers.
SUMMARY OF THE INVENTIONThe object of the present invention is to provide a process for the manufacture of an environmental friendly paper, in which the paper comprises up to about 80% by weight of inorganic mineral powders as main components, about 43% to 18% by weight of polyethylene, and less than 2% by weight of additives.
Another object of the invention is to provide a process for the manufacture of an environmental friendly paper, in which a combination of at least one extruder and a forming mould having an ∘-shaped gate is used to extrude the components as an ∘-shaped film tube and the ∘-shaped film tube is inflated so that the film is stretched in two dimensional direction simultaneously.
Yet another object of the invention is to provide a process for the manufacture of an environmental friendly paper, in which the density of the paper is reduced from about 2 g/cm3 of the combination of the raw materials to as low as about 0.5 g/cm3, saving an amount of up to 40% volume when compared with the density of pulp of about 0.7 g/cm3 to about 0.9 g/cm3.
Yet another object of the present invention is to provide a process for the manufacture of an environmental friendly paper, in which the paper posseses similar properties as those of pulp paper, such as foldability, stiffness, opaqueness, writing ability, and latitudinal and longitudinal tearing strength.
Yet another object of the present invention is to provide a process for the manufacture of an environmental friendly paper, in which neither toxic gas nor smoke is produced when the paper produced is burned because only a minor amount of high density polyethylene is burned, and the paper produced is recyclable.
Yet another object of the present invention is to provide a process for the manufacture of an environmental friendly paper, in which a single-layered paper produced will decompose in a natural environment.
The above features and advantages of the present invention will be better understood with reference to the accompanying figures, detailed description and examples. It should also be understood that the particular environmental friendly paper illustrating the present invention is exemplary only and not to be regarded as a limitation of the invention.
BRIEF DESCRIPTION OF THE DRAWINGSReference is now made to the accompanying figures in which certain figures illustrate embodiment of the present invention from which its novel features and advantages will be apparent:
By way of illustration and to provide a more complete appreciation of the present invention with many of the attendant advantages thereof, the following detailed description is given concerning the process for the manufacture of this paper.
In the process for the manufacture of a single-layered environmental friendly paper of the present invention a composition comprising about 56% to about 80% by weight of inorganic mineral powders as main components, about 43% to about 18% by weight of polyethylene and about 1% to about 2% by weight of additives is used. The inorganic mineral powders include at least two components selected from the group consisting of calcium carbonate, calcium sulfate, barium sulfate, kaolin, mica, zinc oxide, dolomite, glass fiber, hollow glass microbead, silica, chalk, talc, pigment, titanium dioxide, silica dioxide, bentonite, clay and diatomaceous earth and mixtures thereof, which have been sintered or not. Polyethylene includes high density polyethylene or a combination of high density polyethylene and at least one selected from the group consisting of medium density polyethylene (i.e., linear low density polyethylene), and low density polyethylene. The additives include those conventionally used in the art, such as coupling agents, lubricants, dispersant agents, and antistatic agents.
The coupling agent is for instance a silane coupling agent such as beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane.
An example of lubricants is N-oleyl palmitamide. The antistatic agent is, for example, N,N-bis(2-hydroxyethyl)cocoamine or N,N-bis)2-hydroxyethyl)stearyl amine.
After a series of treatment steps of mixing, extruding, milling, and polymerizing, the combination of the above-mentioned raw materials turn into granulates. Referring to
Next, the paper film tube 3 is inflated, for example by pressured air through a passage (not shown) in the forming mould 1. At the same time, one end of the initially moulded paper film tube 3 is drawn by a leading roller 6. The rotation speed of the leading roller 6 is controlled so that the paper film tube 3 is substantially air-tight. The rotating speed of the leading roller 6, the amount of the extruded materials from the extruder 10, and the required thickness of the paper film tube 3 are suitably controlled so that the paper film tube 3 is inflated three to eight times at a distance of about 200 mm to about 700 mm from the gate of the forming mould 1. The purpose of the inflation and drawing is to simultaneously stretch the paper film tube 3 in two directions, i.e., latitudinally and longitudinally, resulting in an environmental friendly paper 4 having a structure with two dimensional strength. Under the action of inflation, the density of the environmental friendly paper 4 can be reduced from that of the combination of the raw materials about 2 g/cm3 to about 0.5 g/cm3, saving all amount of up to about 40% volume when compared with the density of pulp which is about 0.7 g/cm3 to about 0.9 g/cm3. Because the drawing force from the leading roller 6, the environmental friendly paper 4 is drawn into a folding means 5 provided between the leading roller 6 and the cooling means 2 so that the environmental friendly paper 4 is symmetrically folded into a folded flat paper. The purposes of the leading roller 6 include drawing the initially formed paper film tube 3 with a low rotation speed so that the wind from the cooling means 2 is evenly blown thereto and stabilizing the paper film tube 3, and maintaining the paper film tube 3 air-tight so that the paper film tube 3 is evenly inflated. Also, the rotation speed of the leading roller 6 is an essential factor to the longitudinal stretch and the required thickness of the paper film. Of course, the rotation speed should be suitably adjusted to comply with the amount of extruded materials coming from the extruder 10. Then, the folded environmental friendly paper passes a cutting means 7 so that the folded paper is cut into two sheets of paper. The two resulting sheets of the environmental friendly paper are each subjected to treatment of a surface corona means 8 so that numerous microvoids are formed on the two surfaces of each environmental friendly paper and better adhesion can be obtained therefrom. The environmental friendly paper is then collected on a roll 9. During the process for the manufacture of a single-layered environmental friendly paper, the thickness of the paper can be suitably controlled within a range from about 30 μm to about 150 μm, the width can be about 0.2 m to about 3.2 m, and the density can be about 0.4 g/cm3 to about 1 g/cm3.
The present invention is also directed to a process for the manufacture of a double-layered environmental friendly paper. The differences between this process and that of the single-layered paper are explained in two aspects.
The process of the manufacture of the double-layer environmental friendly paper is similar to that of the single-layered paper, except that the single inner passage 101 and the inlet of the forming mould 1 are replaced by two inner passages 101 and 111 and two inlets of a forming mould 1a. Referring to
With respect to the raw materials for this process, the double-layered environmental friendly paper, referring to
According to the process for the manufacture of a double-layered environmental friendly paper, the thickness of the paper ranges from about; 30 μm to about 150 μm and the density ranges from about 0.4 g/cm3 to about 1 g/cm3. The relative thickness of the A layer and B layer can be adjusted as required, for example, 20% A layer and 80% B layer, 50% A layer and 50% B layer, 80% A layer and 20% B layer.
Double-layered environmental friendly papers can be used for printing, packaging, and decoration, etc. Each layer of these products can be designed with different colors as required (for instance, one layer is light red and the other layer is light yellow) by adding different pigments thereto. Double-layered environmental friendly papers have the same advantages as those of the single-layered papers.
The present invention is also directed to a process for the manufacture of a triple-layered environmental friendly paper. The differences between this process and the process for the manufacture of a single-layered environmental friendly paper are explained in the following two aspects.
The process of the manufacture of a triple-layered environmental friendly paper is similar to that of the single-layered environmental friendly paper, except that the single inner passage 101 and the inlet of the forming mould 1 are replaced by three inner passages 101, 111 and 121 and three inlets of a forming mould 1b. Referring to
Regarding the raw materials for this process, the triple-layered environmental friendly paper, referring to
According to the process for the manufacture of a triple-layered environmental friendly paper, the thickness of the paper ranges from about 30 μm to about 150 μm. The relative thickness of the A layer, B layer, and C layer can be adjusted as required, for example, 10% to 25% of the A layer, 80% to 50% of the B layer, and 10% to 25% of the C layer. The triple-layered paper can be used for printing, packaging, decoration, and bags, etc. Each surface layer, i.e., A layer and C layer, of this product can be designed with different colors as required by adding different pigments thereto. Each combination of the components of the A layer, B layer, and C layer can be adjusted so as to for example increase the tensile strength of the paper for different purposes and at the same time using a higher amount of inorganic powders in the B layer, dramatically reducing costs.
It should be understood that the process of the present invention can be used to produce environmental friendly papers having more than three layers on the basis of the above-mentioned general procedures.
Single-layered environmental friendly papers, double-layered environmental friendly papers, triple-layered environmental friendly papers, and even environmental friendly papers having more than three layers of the present invention each independently having a thickness in a range of about 30 μm to about 150 μm and independently having the same or different components can be laminated by a laminating machine as shown in
The single-layered environmental friendly papers, double-layered environmental friendly papers, triple-layered environmental friendly papers, and even environmental friendly papers having more than three layers manufactured according to the process of the present invention can be further laminated to form laminated environmental friendly papers for specific purposes. Referring to
The environmental friendly papers manufactured according to the present invention can be applied to the field of printing, packaging, and decoration. Some of them can be used directly without any pretreatment while some of them need suitable pretreatment, for instance glossy surface treatment and hazy surface treatment, for special purposes. Both water borne coatings and non-water borne coatings can be used to coat the papers manufactured using the present invention. The formulation of water borne coating is comprised of acrylic resin, isopropanol, polyvinyl alcohol, clays, an anti-static agent, 28% aqueous ammonia, pure water, and vinyl acetate.
Referring to
The environmental friendly paper as shown in
Environmental friendly papers of the present invention will now be further illustrated with reference to the following examples.
EXAMPLE 1 Single-Layered Environmental Friendly Paper A single-layered environmental friendly paper is produced from a combination of 60% by weight of inorganic mineral powders (28% by weight of calcium carbonate, 7% by weight of titanium dioxide, and 25% by weight of diatomaceous earth), 38% by weight of polyethylene (20% by weight of high density polyethylene, 10% by weight of low density polyethylene, and 8% by weight of medium density polyethylene), and 2% by weight of additives (0.8% by weight of beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane, 0.4% by weight of N-oleyl palmitamide, and 0.8% by weight of N,N-bis(2-hydroxyethyl)stearyl amine). The combination is subjected to the steps of mixing, extruding, milling, and polymerizing, and it results in granulates. The granulates are fed into the extruder as shown in
A single-layered environmental friendly paper is produced from a combination of 70% by weight of inorganic mineral powders (35% by weight of calcium carbonate, 6% by weight of titanium dioxide, 24% by weight of diatomaceous earth, and 5% by weight of clay), 28% by weight of polyethylene (200%0 by weight of high density polyethylene, and 8% by weight of medium density polyethylene), and 2% by weight of additives (0.8% by weight of beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane, 0.4% by weight of N-oleyl palmitamide, and 0.8% by weight of N,N-bis(2-hydroxyethyl)stearyl amine). The combination is subjected to the steps of mixing, extruding, milling, and polymerizing and results in granulates. The granulates are fed into the extruder as shown in
A single-layered environmental friendly paper is produced from a combination of 80% by weight of inorganic mineral powders (35% by weight of calcium carbonate, 5% by weight of titanium dioxide, 35% by weight of diatomaceous earth, and 5% by weight of talc), 18% by weight of polyethylene (high density polyethylene), and 2% by weight of additives (0.8% by weight of beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane, 0.4% by weight of N-oleyl palmitamide, and 0.8% by weight of N,N-bis(2-hydroxyethyl)stearyl amine). The above combination is subjected to the steps of mixing, extruding, milling, and polymerizing and results in granulates. The granulates are fed into the extruder as shown in
A double-layered environmental friendly paper is composed of an A layer and a B layer. The A layer is produced from a combination of 60% by weight of natural inorganic mineral powders (30% by weight of calcium carbonate, 5% by weight of titanium dioxide, 25% by weight of diatomaceous earth), 38% by weight of polyethylene (high density polyethylene), and 2% by weight of additives (0.8% by weight of beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane, 0.4% by weight of N-oleyl palmitamide, and 0.8% by weight of N,N-bis(2-hydroxyethyl)stearyl amine). The combination is subjected to the steps of mixing, extruding, milling, and polymerizing, and it results in the first granulates. The B layer is produced from a combination of 70% by weight of inorganic mineral powders (32% by weight of calcium carbonate, 3% by weight of titanium dioxide, 32% by weight of diatomaceous earth, and 3% by weight of red pigment), 28% by weight of polyethylene (18% by weight of high density polyethylene and 10% by weight of medium density polyethylene), and 2% by weight of additives (0.8% by weight of beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane, 0.4% by weight of N-oleyl palmitamide, and 0.8% by weight of N,N-bis(2-hydroxyethyl)stearyl amine). The combination is subjected to the steps of mixing, extruding, milling, and polymerizing, and it results in the second granulates. The first granulates and second granulates are fed into extenders 10 and 11, respectively, as shown in
A triple-layered environmental friendly paper is composed of an A layer, a B layer, and a C layer. The A layer is produced from a combination of 60% by weight of inorganic mineral powders (30% by weight of calcium carbonate, 3% by weight of titanium dioxide, 24% by weight of diatomaceous earth, and 3% by weight of red pigment), 38% by weight of polyethylene (high density polyethylene), and 2% by weight of additives (0.8% by weight of beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane, 0.4% by weight of N-oleyl palmitamide, and 0.8% by weight of N,N-bis(2-hydroxyethyl)stearyl amine). The above combination is subjected to the steps of mixing, extruding, milling, and polymerizing and results in the first granulates. The B layer is produced from a combination of 80% by weight of inorganic mineral powder (45% by weight of calcium carbonate, 5% by weight of titanium dioxide, and 30% by weight of diatomaceous earth), 18% by weight of polyethylene (medium density polyethylene), and 2% by weight of additive (0.8% by weight of beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane, 0.4% by weight of N-oleyl palmitamide, and 0.8% by weight of N,N-bis(2-hydroxyethyl)stearyl amine). The combination is subjected to the steps of mixing, extruding, milling, and polymerizing and results in the second granulates. The C layer is produced from a combination of 60% by weight of inorganic mineral powders (30% by weight of calcium carbonate, 3% by weight of titanium dioxide, 24% by weight of diatomaceous earth, and 3% by weight of yellow pigment), 38% by weight of polyethylene (high density polyethylene), and 2% by weight of additives (0.8% by weight of beta-(3,4-epoxycyclohexyl)ethyltrimethoxy-silane, 0.4% by weight of N-oleyl palmitamide, and 0.8 weight % N,N-bis(2-hydroxyethyl)stearyl amine). The combination is subjected to the steps of mixing, extruding, milling, and polymerizing and results in the third granulates. The first, second, and third granulates are fed into extruders 10, 11, and 12, respectively, as shown in
The following table provides testing results of the environmental friendly papers of Examples 1 to 3.
-
- Test standards for the above data are list below.
- Thickness: TAPP T-411
- Grammage: TAPPI T-410
- Apparent density: ISO 534
- Brightness: TAPPI T-452
- Opacity TAPPI T-425
- Tearing strength: (TAPPI T-414)
- Tensile strength: TAPPI T-404
The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the present invention. The present embodiments are, therefore, to be considered in all respects as an illustration and not restrictive. Therefore, any changes coming within the meaning and equivalency range of the appended claims are to be embraced therein.
Claims
1. A process for the manufacture of an environmental friendly paper, comprising
- forming granulates from a combination of about 56% to about 80% by 5 weight of inorganic mineral powders, about 43% to 18% by weight of polyethylene, and about 1% to 2% by weight of additives by the steps of mixing, extruding, milling, and polymerizing;
- applying said granulates into a paper film producing means which comprises at least one extruder and a forming mould having an ∘-shaped gate, said forming mould having at least one inlet thereon, each said inlet defining an inner passage in said forming mould and communicating with said gate of said forming mould;
- melting said granulates in said extruder, transferring said melted granulates to said inlet of said forming mould, and moulding said melted granulates into a hollow film tube substantially corresponding to said ∘-shaped gate;
- cooling said film tube; and
- inflating said film tube and pulling an end of said film tube so that said film tube is stretched in two dimension simultaneously to form said environmental friendly paper.
2. A process according to claim 1, further comprising a step of directing said paper into a folding means to form a folded paper.
3. A process according to claim 2, further comprising a step of directing said folded paper to a cutting means so that said folded paper is cut into two sheets of paper.
4. A process according to claim 1, wherein said extruder is at a temperature in the range from about 150° C. to about 220° C.
5. A process according to claim 1, wherein said film tube is moulded upward by said forming mould.
6. A process according to claim 1, wherein said film tube is cooled to about 80° C. to about 120° C. at a distance from about 30 mm to about 700 mm from said gate of said forming mould.
7. A process according to claim 1, wherein said paper film producing means comprises one extruder and a forming mould having an inlet and an inner passage.
8. A process according to claim 1, wherein said paper film producing means comprises two extruders and a forming mould having two inlets and two inner passages.
9. A process according to claim 1, wherein said paper film producing means comprises three extruders and a forming mould having three inlets and three inner passages.
10. A process according to claim 3, wherein said paper has a thickness from about 30 mm to about 150 mm.
11. A process according to claim 3, wherein said paper can be laminated to form a laminated paper having a thickness from about 150 mm to about 450 mm.
12. A process according to claim 3, wherein said paper is further subjected to coating.
13. A process according to claim 1, wherein said inorganic mineral powders are selected from the group consisting of calcium carbonate, calcium sulfate, barium sulfate, kaolin, mica, zinc oxide, dolomite, glass fiber, hollow glass microbead, silica, chalk, talc, pigment, titanium dioxide, silica dioxide, bentonite, clay, diatomaceous earth and mixtures thereof.
14. A process according to claim 1, wherein said polyethylene comprises high density polyethylene, or a combination of high density polyethylene with at least one selected from the group consisting of medium density polyethylene and low density polyethylene.
15. A process according to claim 1, wherein said additives comprise coupling agents, lubricants, anti-static agents, and mixtures thereof.
16. A composition for the manufacture of an environmental friendly paper, comprising about 56% to 80% by weight of inorganic mineral powders, about 43% to 18% by weight of polyethylene, and about 1% to 2% weight by additives.
17. A composition according to claim 16, wherein said inorganic mineral powders are selected from the group consisting of calcium carbonate, calcium sulfate, barium sulfate, kaolin, mica, zinc oxide, dolomite, glass fiber, hollow glass microbead, silica, chalk, talc, pigment, titanium dioxide, silica dioxide, bentonite, clay, diatomaceous earth and mixtures thereof.
18. A composition according to claim 16, wherein said polyethylene comprises high density polyethylene, or a combination of high density polyethylene with at least one selected from the group consisting of medium density polyethylene and low density polyethylene.
19. A process according to claim 16, wherein said additives comprise coupling agents, lubricants, and anti-static agents and mixtures thereof.
Type: Application
Filed: Sep 22, 2003
Publication Date: May 12, 2005
Applicant:
Inventor: Shih Liang (Tainan County)
Application Number: 10/668,048