Disclosure of Invention
The invention aims to provide a production process for preparing a varnished leather by utilizing a cyclic regeneration leather blank, which is simple in step and convenient to operate and control, solves the problems of unevenness and obvious spunlace line of the cyclic regeneration leather blank, changes a short plate of the cyclic regeneration leather blank, enables the cyclic regeneration leather blank with poor grade to be changed into a high-end varnished leather fabric, and greatly improves the added value of products.
The invention aims to realize the following technical scheme, and the production process for preparing the lacquer leather by utilizing the recycled reclaimed leather blank comprises the following steps:
(1) selecting materials: adopting the recycled regenerated leather as a leather blank;
(2) spraying filling resin: heating the PUR glue to 120 ℃ by adopting hot melting equipment, melting the PUR glue into liquid, injecting the liquid into a pipeline, uniformly spraying the liquid onto the uneven spunlace surface of the recycled leather blank, and spraying filling resin on the spunlace surface of the recycled leather blank;
(3) drying: putting the sprayed recycled leather blank into an oven of a spraying line, and drying and rolling;
(4) flattening: putting the dried circularly regenerated leather blank into a roller flattening machine for flattening to flatten the surface of the leather blank;
(5) laminating a PU film layer:
dry green sheet using a multi-nozzle feed system and a multi-knife coaterThe production line is used for arranging the PET film on a machine, feeding the PET film into a first blade coater, uniformly blade-coating a first layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the first layer of waterborne polyurethane resin is 100-plus-120 g/m2The thickness is 8-12 mu m;
enters a second blade coater through a first section 15m drying channel, and is uniformly blade-coated with a second layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade coating density of the second layer of waterborne polyurethane resin is 200-one-step 250g/m2The thickness is 15-20 mu m, and the polyurethane material layer mainly plays a role in flatness and support;
enters a third blade coating machine through a second section of 35m drying channel, and is uniformly blade-coated with a third layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade coating density of the third layer of waterborne polyurethane resin is 120g/m2The thickness is 8-12 mu m;
through a third 10m drying channel, forming a PU film on the dried waterborne polyurethane resin layer, laminating the PET film with the PU film layer and the flattened recycled leather blank through a laminating machine to obtain a semi-finished leather blank, conveying the semi-finished leather blank to a laminating machine for laminating, and cooling the semi-finished leather blank through six rollers with cold water circulation mirror surfaces after passing through a semi-finished leather blank drying channel to obtain a semi-finished product;
(6) peeling the PET film:
and (3) putting the semi-finished product into a separator for separation and winding, stripping the high-transparency PET film, transferring the PU film to the surface of the recycled leather blank, and standing for 10-24h to obtain the lacquer leather.
Preferably, the filling resin in the step (2) is composed of the following raw materials in parts by weight:
50-80 parts of polyurethane resin,
10-30 parts of collagen powder,
5-20 parts of a thickening agent,
80-150 parts of distilled water.
The collagen powder is prepared by grinding and mixing dermal waste and resin.
The granularity of the collagen powder is 1200 meshes.
Preferably, the temperature of the oven in the step (3) is set to be 80-120 ℃, and the rolling speed is 4-8 m/min.
Preferably, said step(4) The set temperature of the medium pressing machine is 60-100 ℃, and the pressure is 5-10kg/cm2The passing speed is 5-10 m/min.
Preferably, the setting temperature of the laminating machine in the step (5) is 80-120 ℃, and the pressure is 5-10kg/cm2。
Preferably, the temperature of the pressing machine in the step (5) is set to be 80-150 ℃, and the pressure is set to be 5-15kg/cm2。
Preferably, the thickness of the high transparent PET film in the step (5) is 40-100 μm.
Preferably, the drying temperature of the drying tunnel in the step (5) is 80-120 ℃, and the conveying speed of the production line is 4-8 m/min.
The invention has the beneficial effects that:
the production process of the invention has simple steps and convenient operation and control, the material is recycled by leather leftover materials, the raw materials are cheap and easy to obtain, the utilization rate of the leather materials is high, the production cost is low, and the large-scale industrial production can be realized.
The invention prepares the paint leather by combining the leather roller coating spraying process with the water-based PU dry-method film transfer process, and reduces the discharge of VOCs by using the water-based film transfer process to replace an oil process.
The finished product of the paint coat prepared by the invention has strong permeability and high surface brightness, can clearly see the reflection of an article, has the normal-temperature flexing resistance test of more than 50 ten thousand times and the low-temperature 30 ℃ test of 3 ten thousand times, can be applied to industries such as shoe materials, clothes, cases, furniture and the like, and greatly improves the added value of products.
Detailed Description
The present invention will be further described with reference to the following examples for facilitating understanding of those skilled in the art, and the description of the embodiments is not intended to limit the present invention.
The reagents or instruments used in the present invention are not indicated by manufacturers, and are all conventional products commercially available.
Example 1
A production process for preparing a lacquer leather by utilizing a recycled leather blank comprises the following steps:
(1) selecting materials: adopting the recycled regenerated leather as a leather blank;
(2) spraying filling resin: firstly, heating the PUR adhesive to 120 ℃ by adopting hot melting equipment, melting the PUR adhesive into liquid, then injecting the liquid into a pipeline to uniformly spray the liquid onto the rugged spunlace surface of the cyclic regeneration leather blank, and then spraying resin on the spunlace surface of the cyclic regeneration leather blank, wherein the filling resin is prepared by mixing the following raw materials in parts by weight:
60 parts of polyurethane resin, namely 60 parts of polyurethane resin,
30 parts of collagen powder, namely 30 parts of collagen powder,
10 parts of a thickening agent, namely 10 parts of,
100 parts of distilled water;
wherein the collagen powder is prepared by grinding and mixing dermal waste and resin, and the granularity of the collagen powder is 1200 meshes;
(3) drying: placing the sprayed recycled reclaimed leather blank into an oven of a spraying line, setting the temperature of the oven to be 100 ℃, and drying and rolling at the rolling speed of 6 m/min;
(4) flattening: placing the dried circularly regenerated leather blank into a roller flattening machine for flattening to flatten the surface of the leather blank, wherein the temperature of the flattening machine is 80 ℃, and the pressure is 10kg/cm2Passing speed of 10 m/min;
(5) laminating a PU film layer:
a high-transparency PET film with the thickness of 50 mu m and the width of 1.5m is arranged on a machine, the drying tunnel temperature of a dry production line is set to be 120 ℃, and the conveying speed of the production line is 5 m/min.
Entering a first blade coater, uniformly blade-coating a first layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the first layer of waterborne polyurethane resin is 120g/m210 μm thick;
entering a second blade coater through a first section 15m drying tunnel, uniformly blade-coating a second layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade coating density of the second layer of waterborne polyurethane resin is 240g/m2The thickness is 20 mu m, and the layer of polyurethane material mainly plays a role in flatness and support;
entering a third blade coating machine through a second section of 35m drying tunnel, and uniformly blade-coating a third layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade coating density of the third layer of waterborne polyurethane resin is 120g/m2Thickness of the film10μm;
Through a third 10m drying channel, forming a PU film on the dried waterborne polyurethane resin layer, laminating the PET film with the PU film layer and the flattened recycled leather blank through a laminating machine to obtain a semi-finished leather blank, conveying the semi-finished leather blank to a laminating machine for laminating, and cooling the semi-finished leather blank through six rollers with cold water circulation mirror surfaces after passing through a semi-finished leather blank drying channel to obtain a semi-finished product; wherein the setting temperature of the laminating machine is 120 ℃, and the pressure is 5kg/cm2The setting temperature of the pressing machine is 80 ℃, and the pressure is 5kg/cm2。
(6) Peeling PET film
And (3) separating and rolling the semi-finished product by a roll separator, stripping the high-transparency PET film, transferring the PU film to the surface of the recycled leather blank, and standing for 24 hours to obtain the lacquer leather.
Example 2
This embodiment differs from embodiment 1 described above in that:
the filling resin in the step (2) is prepared by mixing the following raw materials in parts by weight:
50 parts of polyurethane resin, namely polyurethane resin,
20 parts of collagen powder, namely 20 parts of collagen powder,
5 parts of a thickening agent, namely 5 parts of,
80 parts of distilled water;
in the step (3), the temperature of the oven is set to 80 ℃, and the winding speed is 4 m/min.
In the step (4), the setting temperature of the flattening machine is 60 ℃, and the pressure is 5kg/cm2Passing speed 5 m/min;
the thickness of the high-transparent PET film in the step (5) is 40 μm.
In the step (5), the drying temperature of the drying tunnel is 80 ℃, and the conveying speed of the production line is 4 m/min.
Step (5), entering a first blade coater, uniformly blade-coating a first layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the first layer of waterborne polyurethane resin is 100g/m2And a thickness of 8 μm.
And (5) entering a second blade coater through a first section of 15m drying tunnel, uniformly blade-coating a second layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the second layer of waterborne polyurethane resin is 250g/m218 μm thick, the layer of polyurethane material mainly plays a role in flatness and support.
And (5) entering a third blade coating machine through a second section of 35m drying tunnel, and uniformly blade-coating a third layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the third layer of waterborne polyurethane resin is 120g/m2And a thickness of 12 μm.
In the step (5), the setting temperature of the laminating machine is 110 ℃, and the pressure is 6kg/cm2。
In the step (5), the setting temperature of the pressing machine is 100 ℃, and the pressure is 8kg/cm2。
And (5) standing for 10 h.
Example 3
This embodiment differs from embodiment 1 described above in that:
the filling resin in the step (2) is prepared by mixing the following raw materials in parts by weight:
80 parts of polyurethane resin, namely 80 parts of polyurethane resin,
10 parts of collagen powder, namely 10 parts of collagen powder,
15 parts of a thickening agent, namely 15 parts of,
120 parts of distilled water.
In the step (3), the temperature of the oven is set to be 110 ℃, and the winding speed is 5 m/min.
The setting temperature of the flattening machine in the step (4) is 90 ℃, and the pressure is 6kg/cm2The passing speed was 6 m/min.
The thickness of the high-transparent PET film in the step (5) is 80 μm.
The drying temperature of the drying tunnel in the step (5) is 100 ℃, and the conveying speed of the production line is 6 m/min.
Step (5), entering a first blade coating machine, uniformly blade-coating a first layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the first layer of waterborne polyurethane resin is 110g/m2And a thickness of 11 μm.
And (5) entering a second blade coater through a first section of 15m drying tunnel, uniformly blade-coating a second layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the second layer of waterborne polyurethane resin is 220g/m216 μm thick, the layer of polyurethane material mainly plays a role in flatness and support.
And (5) entering a third blade coating machine through a second section of 35m drying tunnel, and uniformly blade-coating a third layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the third layer of waterborne polyurethane resin is 110g/m2And a thickness of 11 μm.
In the step (5), the setting temperature of the laminating machine is 120 ℃, and the pressure is 12kg/cm2。
In the step (5), the setting temperature of the pressing machine is 100 ℃, and the pressure is 6kg/cm2。
And (5) standing for 15 h.
Example 4
This embodiment differs from embodiment 1 described above in that:
the filling resin in the step (2) is prepared by mixing the following raw materials in parts by weight:
70 parts of polyurethane resin, namely 70 parts of polyurethane resin,
30 parts of collagen powder, namely 30 parts of collagen powder,
20 parts of a thickening agent, namely 20 parts of,
150 parts of distilled water.
In the step (3), the temperature of the oven is set to be 120 ℃, and the winding speed is 8 m/min.
In the step (4), the setting temperature of the flattening machine is 100 ℃, and the pressure is 8kg/cm2The passing speed was 8 m/min.
The thickness of the high transparent PET film in the step (5) is 100 mu m.
The drying temperature of the drying tunnel in the step (5) is 120 ℃, and the conveying speed of the production line is 8 m/min.
Step (5), entering a first blade coating machine, uniformly blade-coating a first layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the first layer of waterborne polyurethane resin is 120g/m2And a thickness of 12 μm.
And (5) entering a second blade coater through a first section of 15m drying tunnel, uniformly blade-coating a second layer of waterborne polyurethane resin on the surface of the PET film, wherein the blade-coating density of the second layer of waterborne polyurethane resin is 250g/m218 μm thick, the layer of polyurethane material mainly plays a role in flatness and support.
Step (5) enters a third blade coating machine through a second section of 35m drying tunnel, and the surface of the PET film is uniformly blade-coatedThree layers of waterborne polyurethane resin, wherein the blade coating density of the third layer of waterborne polyurethane resin is 120g/m2And a thickness of 12 μm.
In the step (5), the setting temperature of the laminating machine is 100 ℃, and the pressure is 12kg/cm2。
In the step (5), the set temperature of the pressing machine is 150 ℃, and the pressure is 15kg/cm2。
And (5) standing for 20 h.
The finished paint skins prepared in examples 1-4 have high permeability and high surface brightness, and the reflection of the article can be seen clearly.
The finished product of the lacquer leather prepared in the embodiments 1 to 4 is subjected to normal-temperature and low-temperature bending-resistant tests at minus 30 ℃ by a leather bending-resistant testing machine, the normal-temperature bending-resistant tests of the finished product of the lacquer leather exceed 50 ten thousand times, the low-temperature testing at minus 30 ℃ can reach 3 ten thousand times, the finished product of the lacquer leather can be applied to industries such as shoe materials, clothes, cases, furniture and the like, and the added value of the product is greatly improved.
The above-described embodiments are preferred implementations of the present invention, and the present invention may be implemented in other ways without departing from the spirit of the present invention.