阅读说明：本技术 一种tpu热塑性聚氨酯薄膜挤出加工工艺 (TPU thermoplastic polyurethane film extrusion processing technology ) 是由 顾国才 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种TPU热塑性聚氨酯薄膜挤出加工工艺,涉及TPU薄膜制作技术领域；为了解决产品质量不佳问题；具体包括如下步骤：将TPU粒子放在25mm以下的浅盘中,放入烘箱干燥,使得TPU粒子湿气水质分数＜0.07％；将预热后的TPU粒子加入排放至双螺杆挤出机的加热料筒内受热熔融；在双螺杆挤出机螺杆的旋转作用下实现对熔融物料的输送、塑化、压实。本发明将TPU材料预热后受热、熔融后,经过过滤再挤出至I型模,由I型模调整至厚度均一后挤出流延成薄膜,最后冷却成型,可根据需要自由设定产品的长度,得到的薄膜展平度高,无留痕,厚度均匀,厚度范围可控制在0.01mm～0.1mm范围,弹性强,强度高。(The invention discloses an extrusion processing technology of a TPU thermoplastic polyurethane film, relating to the technical field of TPU film manufacturing; in order to solve the problem of poor product quality; the method specifically comprises the following steps: putting the TPU particles in a tray with the diameter of less than 25mm, and putting the tray in an oven for drying to ensure that the moisture water quality fraction of the TPU particles is less than 0.07 percent; adding the preheated TPU particles into a heating charging barrel of a double-screw extruder, and heating and melting the TPU particles; the conveying, plasticizing and compacting of the molten material are realized under the rotation action of a screw of the double-screw extruder. The TPU material is preheated, heated and melted, filtered, extruded to the I-shaped die, adjusted to be uniform in thickness by the I-shaped die, extruded and cast into a film, and finally cooled and formed, the length of the product can be freely set according to needs, the obtained film is high in flatness, free of left marks, uniform in thickness, controllable in thickness range from 0.01mm to 0.1mm, strong in elasticity and high in strength.)

1. The TPU thermoplastic polyurethane film extrusion processing technology is characterized by comprising the following steps:

s1: putting the TPU particles in a tray with the diameter of less than 25mm, and putting the tray in an oven for drying to ensure that the moisture water quality fraction of the TPU particles is less than 0.07 percent;

s2: adding the preheated TPU particles into a heating charging barrel of a double-screw extruder, and heating and melting the TPU particles;

s3: conveying, plasticizing and compacting the molten material under the rotation action of a screw of the double-screw extruder, filtering the molten material by a filter, and extruding the molten material from a neck mold to an I-shaped die;

s4: adjusting the molten material flowing into the I-shaped die to be uniform in thickness, extruding, and casting into a film;

s5: fully cooling by utilizing circulating air;

s6: the cooled film is flattened by a flattening device;

s7: uniformly slitting the flattened film in equal length;

s8: and packaging to obtain a final finished product.

2. The extrusion processing technology of TPU thermoplastic polyurethane film as claimed in claim 1, wherein the oven temperature in S1 is 100 ℃ and the drying time is 2 h.

3. The extrusion processing process of TPU thermoplastic polyurethane film as claimed in claim 2, wherein the parameters of the twin-screw extruder in S2 for melting by heating are as follows: the temperature of a charging barrel at a feeding section is 150 ℃, the temperature of a charging barrel at a melting section is 170 ℃, the temperature of a charging barrel at a metering section is 180 ℃, the temperature of a machine head is 185 ℃, the temperature of a neck mold is 190 ℃, and the temperature of a material is controlled to be 170 ℃.

4. The extrusion processing process of TPU thermoplastic polyurethane film as claimed in claim 3, wherein the rotation speed of the screw in S3 is controlled at 40r/min and the mesh density of the filter is 40 meshes.

5. The extrusion processing technology of TPU thermoplastic polyurethane film as claimed in claim 4, wherein in S4, the film thickness is 0.1mm and the film width is 3000 mm.

6. The extrusion processing process of TPU thermoplastic polyurethane film as claimed in claim 5, wherein the thickness of the film is controlled by the screw speed or casting speed ratio and the width of the film is controlled by the I-die and cutter device.

7. The extrusion processing process of TPU thermoplastic polyurethane film as claimed in claim 1, wherein the preparation method of TPU particles in S1 comprises the following steps:

s21: mixing 4-4' -diphenylmethane diisocyanate 40%, polytetrahydrofuran 40%, 1, 4-butanediol 25% and adipic acid 35% in proportion, and reacting mainly as follows

HO～～OH+OCN-Ar-NCO→-[-O～～OCONH-Ar-NHCO-]_n-；

S22: mixing, pouring into a double-screw reaction extruder, continuously granulating under water at the high temperature of 220 ℃ and the extrusion pressure of 5MPa, dehydrating and drying by adopting a centrifugal particle dryer, and curing for 10 hours to obtain a finished product.

8. The extrusion processing process of TPU thermoplastic polyurethane film as claimed in claim 7, wherein said twin-screw reaction extruder has the following technical specifications: the length-diameter ratio is more than or equal to 52, the screw is made of 900HV nitriding steel, the machine barrel is made of 800HV nitriding steel, the motor of the brake is in direct current frequency conversion, the temperature adjusting mode is electric heating or water cooling, the temperature of the machine barrel can be set, the error is +/-2, and the rotating speed of the screw is 350 r/min.

9. The extrusion processing process of TPU thermoplastic polyurethane film of claim 8, wherein the centrifugal pellet dryer has the following specifications: the temperature of the granulating water is 8 ℃, the weight of 10 (+/-10%) granules is 28g, the viscosity of the melt is 8kpa · s, the output pressure of the melt is more than or equal to 10Mpa, and the rotating speed of the granulator is 2000 r/min.

Technical Field

The invention relates to the technical field of TPU (thermoplastic polyurethane) film manufacturing, in particular to an extrusion processing technology of a TPU thermoplastic polyurethane film.

Background

Thermoplastic polyurethane TPU is ubiquitous in life, and can be made into shoes, ready-made clothes, inflatable toys, umbrellas, leather cases, leather bags, overwater and underwater sports equipment, medical equipment, body-building equipment, automobile seat materials and the like, TPU films are films prepared by special processes such as calendaring, tape casting, film blowing, coating and the like on the basis of TPU granules, at present, trademark decoration, air bags, air cushions, oil pockets and the like on soles and vamps are widely applied, and at present, the TPU films can be applied to laminating films of high-grade buildings, films for windows of automobiles and trains, shoe materials and the like, wherein compared with cow leather which is expensive and poor in wear resistance, the TPU films have double advantages of cost and performance, and the halogen-free TPU films can avoid the problem that harmful gas is generated when the PVC films are used as interior decoration films, so that the advantages in the aspect of environmental protection are displayed.

Through retrieval, the Chinese patent with the application number of CN201910775960.8 discloses a TPU polyester health care composite film and a production method thereof, wherein the TPU polyester health care composite film comprises 3-9 wt% of anion powder, 3-5 wt% of germanite powder, 3-5 wt% of hexacyclic stone powder, 3-9 wt% of far infrared powder and 72-88 wt% of TPU polyester. The TPU polyester health-care composite membrane and the production method thereof in the patent have the following defects: drying treatment is not carried out before the composite film is extruded, the appearance of a final product is influenced due to high water content of TPU, and the injection-molded product has poor elasticity and low strength.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides an extrusion processing technology of a TPU thermoplastic polyurethane film.

In order to achieve the purpose, the invention adopts the following technical scheme:

an extrusion processing technology of a TPU thermoplastic polyurethane film comprises the following steps:

s1: putting the TPU particles in a tray with the diameter of less than 25mm, and putting the tray in an oven for drying to ensure that the moisture water quality fraction of the TPU particles is less than 0.07 percent;

s2: adding the preheated TPU particles into a heating charging barrel of a double-screw extruder, and heating and melting the TPU particles;

s3: conveying, plasticizing and compacting the molten material under the rotation action of a screw of the double-screw extruder, filtering the molten material by a filter, and extruding the molten material from a neck mold to an I-shaped die;

s4: adjusting the molten material flowing into the I-shaped die to be uniform in thickness, extruding, and casting into a film;

s5: fully cooling by utilizing circulating air;

s6: the cooled film is flattened by a flattening device;

s7: uniformly slitting the flattened film in equal length;

s8: and packaging to obtain a final finished product.

Preferably: the oven temperature in the S1 is 100 ℃, and the drying time is 2 h.

Preferably: the parameters of the double-screw extruder in S2 for melting under heat are as follows: the temperature of a charging barrel at a feeding section is 150 ℃, the temperature of a charging barrel at a melting section is 170 ℃, the temperature of a charging barrel at a metering section is 180 ℃, the temperature of a machine head is 185 ℃, the temperature of a neck mold is 190 ℃, and the temperature of a material is controlled to be 170 ℃.

Preferably: the rotating speed of the screw in the S3 is controlled at 40r/min, and the mesh density of the filter is 40 meshes.

Preferably: in the S4, the thickness of the film is 0.1mm, and the width of the film is 3000 mm.

Preferably: the thickness of the film is controlled by the rotating speed of the screw or the casting speed ratio, and the width of the film is controlled by the I-shaped die and the cutter device.

Preferably: the preparation method of the TPU particles in S1 comprises the following steps:

s21: mixing 4-4' -diphenylmethane diisocyanate 40%, polytetrahydrofuran 40%, 1, 4-butanediol 25% and adipic acid 35% in proportion, and reacting mainly as follows

HO～～OH+OCN-Ar-NCO→-[-O～～OCONH-Ar-NHCO-]_n-；

S22: mixing, pouring into a double-screw reaction extruder, continuously granulating under water at the high temperature of 220 ℃ and the extrusion pressure of 5MPa, dehydrating and drying by adopting a centrifugal particle dryer, and curing for 10 hours to obtain a finished product.

Preferably: the technical indexes of the double-screw reaction extruder are as follows: the length-diameter ratio is more than or equal to 52, the screw is made of 900HV nitriding steel, the machine barrel is made of 800HV nitriding steel, the motor of the brake is in direct current frequency conversion, the temperature adjusting mode is electric heating or water cooling, the temperature of the machine barrel can be set, the error is +/-2, and the rotating speed of the screw is 350 r/min.

Preferably: the centrifugal particle dryer has the following technical indexes: the temperature of the granulating water is 8 ℃, the weight of 10 (+/-10%) granules is 28g, the viscosity of the melt is 8kpa · s, the output pressure of the melt is more than or equal to 10Mpa, and the rotating speed of the granulator is 2000 r/min.

The invention has the beneficial effects that: preheating a TPU material, heating, melting, filtering, extruding to an I-shaped die, adjusting to uniform thickness by the I-shaped die, extruding and casting to form a film, cooling and forming, wherein the raw material is extruded by the I-shaped die, the width of the product is determined by the length of the I-shaped die, the I-shaped die can be longer, the length of the product can be freely set according to needs, the obtained film has high flatness, no left mark, uniform thickness, controllable thickness range of 0.01-0.1 mm, strong elasticity and high strength.

Drawings

FIG. 1 is a schematic flow structure diagram of the TPU thermoplastic polyurethane film extrusion processing technology provided by the invention.

Detailed Description

The technical solution of the present patent will be described in further detail with reference to the following embodiments.

Reference will now be made in detail to embodiments of the present patent, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present patent and are not to be construed as limiting the present patent.

In the description of this patent, it is to be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for the convenience of describing the patent and for the simplicity of description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the patent.

In the description of this patent, it is noted that unless otherwise specifically stated or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly and can include, for example, fixedly connected, disposed, detachably connected, disposed, or integrally connected and disposed. The specific meaning of the above terms in this patent may be understood by those of ordinary skill in the art as appropriate.