Preparation method and device of random dyeing hard microfiber leather

Abstract

The present application relates to the technical field of microfiber synthetic leather, and particularly relates to a preparation method and device of irregularly dyed hard microfiber leather; the method comprises the following steps: mixing nylon 6 and low-density polyethylene according to a mass ratio of 4-6:6-4, melt spinning, and preparing superfine fibers with linear density of 3-6 dtex and 13-16 dtex; mixing the superfine fibers with linear density of 3-6 dtex and the superfine fibers with linear density of 13-16 dtex, needling to make non-woven fabric; incompletely extracting low-density polyethylene from polyurethane resin with high elastic modulus by solvent toluene, and preparing a bottom embryo through oiling and drying; coating three resin layers with different color development effects on the bottom embryo, drying, and preparing irregularly dyed hard microfiber synthetic leather through dyeing and finishing process; the device comprises a mixing box, two feeding pipes, a discharging pipe, two sets of weighing units, a melt spinning machine and a stirrer; through the above method, the irregular mottled color effect can be stably realized, and the dyeing uniformity is good.

Description

Technical Field

[0001] This invention relates to the field of microfiber synthetic leather technology, and in particular to a method and apparatus for preparing random-dyed hard microfiber leather. Background Technology

[0002] Microfiber synthetic leather (microfiber leather), with its three-dimensional mesh fiber structure, has mechanical properties and a feel close to natural leather, and is widely used in bags, shoes, and interior decoration. However, microfiber synthetic leather has limitations: while it boasts excellent performance, it falls short in replicating natural leather. Due to its dense structure and uneven fiber distribution, coupled with the tendency for uneven coloring between the nylon fibers and polyurethane (PU) phases, it suffers from poor evenness and penetration in dyeing, easily resulting in color variations.

[0003] The mainstream existing dyeing technologies are divided into immersion dyeing and greige fabric dyeing. The former has low color vibrancy, while the latter, although bright in color, suffers from poor uniformity and poor color fastness.

[0004] In conclusion, it is essential to propose a method and apparatus for preparing randomly dyed hard microfiber leather that can stably achieve random mottled color effects and has good even dyeing properties. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for preparing random dyeing hard microfiber leather, which achieves a stable random mottled color effect and good uniform dyeing properties.

[0006] To achieve the above objectives, the present invention provides a method for preparing random-dyed hard microfiber leather, comprising the following steps:

[0007] Nylon 6 and low-density polyethylene are mixed in a mass ratio of 4~6:6~4 and melt-spun to produce ultrafine fibers with linear densities of 3~6 dB and 13~16 dB.

[0008] The ultrafine fibers with a linear density of 3-6 dBT are mixed with ultrafine fiber threads with a linear density of 13-16 dBT and then needle-punched to form nonwoven fabric.

[0009] Low-density polyethylene is incompletely extracted from polyurethane resin with a high elastic modulus by solvent toluene, and then oiled and dried to obtain a preform.

[0010] The base material is coated with three resin layers with different color development effects, dried, and then dyed and finished to obtain random-dyed hard microfiber synthetic leather.

[0011] In the step of impregnating a polyurethane resin with a high elastic modulus, incompletely extracting low-density polyethylene with toluene as a solvent, and then oiling and drying it to obtain a preform:

[0012] The resin with high elastic modulus is prepared by reacting N,N-diphenylmethane diisocyanate, ethylene terephthalate, polytetrahydrofuran polyol and ethylene glycol.

[0013] In the process of coating the base material with three resin layers that have different color development effects, drying it, and then performing a dyeing and finishing process to obtain random-dyed hard microfiber synthetic leather:

[0014] The three resin layers with different color development effects include resin SX-1125a, resin SX-1125b, and resin SX-1125c.

[0015] Among them, resin SX-1125a is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol and ethylene glycol.

[0016] Among them, resin SX-1125b is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol, ethylene glycol adipate and ethylene glycol.

[0017] Among them, resin SX-1125c is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol, polycaprolactone polyol and 1,4-butanediol.

[0018] In the process of coating the base material with three resin layers that have different color development effects, drying it, and then performing a dyeing and finishing process to obtain random-dyed hard microfiber synthetic leather:

[0019] The dyeing and finishing process involves dyeing hard microfiber synthetic leather with acid dyes, followed by washing and drying.

[0020] The present invention also provides an apparatus for preparing random dyed hard microfiber leather, comprising a mixing chamber, two feed pipes, a discharge pipe, two sets of weighing units, a melt spinning machine, and a stirrer. Both feed pipes are connected to the mixing chamber and are located above the mixing chamber. The melt spinning machine is located on one side of the mixing chamber. The two ends of the discharge pipe are respectively connected to the mixing chamber and the melt spinning machine. The stirrer is disposed on the mixing chamber. Each set of weighing units is connected to the corresponding feed pipe.

[0021] Furthermore, the weighing unit includes a weighing box, a movable plate, a weight sensor, a spring, a locking block, and an electric push rod. The weighing box is fixedly connected to the feed pipe and located above the feed pipe. The movable plate is rotatably disposed within the weighing box. The two ends of the spring are respectively connected to the weighing box and the movable plate. The weight sensor is fixedly connected to the movable plate and embedded in the movable plate. The weighing box has a groove, and the locking block is movably disposed within the groove. The electric push rod is fixedly connected to the weighing box and located on the outer side wall of the weighing box. The output end of the electric push rod is connected to the locking block.

[0022] This invention discloses a method and apparatus for preparing random-dyed hard microfiber leather. First, nylon 6 and low-density polyethylene are mixed in a mass ratio of 4-6:6-4 and melt-spun to produce microfibers with linear densities of 3-6 dB and 13-16 dB. Then, the microfibers with linear densities of 3-6 dB and 13-16 dB are mixed and needle-punched to form a nonwoven fabric. Next, the fabric is impregnated with a polyurethane resin with a high elastic modulus, and the low-density polyethylene is incompletely extracted using toluene as a solvent. After oiling and drying, a base material is obtained. Finally, the base material is coated with three resin layers with different color development effects, dried, and subjected to dyeing and finishing processes to obtain random-dyed hard microfiber synthetic leather. Through the above method, a stable random mottled color effect and excellent even dyeing properties are achieved. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart of the steps in the preparation method of the random dyeing hard microfiber leather of the present invention.

[0025] Figure 2 This is a schematic diagram of the apparatus for preparing random-dyed hard microfiber leather according to the present invention.

[0026] Figure 3 This is a structural side view of the apparatus for preparing random-dyed hard microfiber leather according to the present invention.

[0027] Figure 4 This is the invention Figure 3 A cross-sectional view of the AA line structure.

[0028] Figure 5 This is a cross-sectional view of the internal structure of the weighing unit of the present invention.

[0029] 101-Mixing box, 102-Feed pipe, 103-Discharge pipe, 104-Melting spinning machine, 105-Agitator, 106-Weighing box, 107-Moving plate, 108-Weight sensor, 109-Spring, 110-Locking block, 111-Electric push rod, 112-Groove. Detailed Implementation

[0030] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0031] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0032] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0033] Please see Figure 1 This invention provides a method for preparing randomly dyed hard microfiber leather, comprising the following steps:

[0034] S100: Made by mixing nylon 6 and low-density polyethylene in a mass ratio of 4~6:6~4, melt spinning to produce ultrafine fibers with linear deniers of 3~6 dB and 13~16 dB.

[0035] S200: Mix ultrafine fibers with a linear density of 3-6 dB and ultrafine fiber threads with a linear density of 13-16 dB, and then needle-punch them into nonwoven fabric.

[0036] S300: Low-density polyethylene is incompletely extracted from polyurethane resin with a high elastic modulus by solvent toluene, and then oiled and dried to obtain a preform.

[0037] S400: The base material is coated with three resin layers with different color development effects, dried, and then dyed and finished to produce random-dyed hard microfiber synthetic leather.

[0038] In this embodiment, nylon 6 and low-density polyethylene are first mixed in a mass ratio of 4~6:6~4 and melt-spun to produce microfibers with linear densities of 3~6 dB and 13~16 dB. Then, the microfibers with linear densities of 3~6 dB and 13~16 dB are mixed and needle-punched to form a nonwoven fabric. Next, the low-density polyethylene is incompletely extracted from polyurethane resin with a high elastic modulus by solvent toluene, and then oiled and dried to obtain a base material. Finally, the base material is coated with three resin layers with different color development effects, dried, and dyed to obtain a random-dyed hard microfiber synthetic leather. Through the above method, a stable random mottled color effect and good dyeing uniformity are achieved.

[0039] Furthermore, in the step of impregnating a polyurethane resin with a high elastic modulus, incompletely extracting low-density polyethylene with toluene as a solvent, and then oiling and drying it to obtain a preform:

[0040] The resin with high elastic modulus is prepared by reacting N,N-diphenylmethane diisocyanate, ethylene terephthalate, polytetrahydrofuran polyol and ethylene glycol.

[0041] Furthermore, in the step of coating the base material with three resin layers with different color development effects, drying, and then performing dyeing and finishing processes to obtain random-dyed hard microfiber synthetic leather:

[0042] The three resin layers with different color development effects include resin SX-1125a, resin SX-1125b, and resin SX-1125c.

[0043] Furthermore, resin SX-1125a is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol and ethylene glycol.

[0044] Furthermore, resin SX-1125b is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol, ethylene glycol adipate, and ethylene glycol.

[0045] Furthermore, resin SX-1125c is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol, polycaprolactone polyol and 1,4-butanediol.

[0046] Furthermore, in the step of coating the base material with three resin layers with different color development effects, drying, and then performing dyeing and finishing processes to obtain random-dyed hard microfiber synthetic leather:

[0047] The dyeing and finishing process involves dyeing hard microfiber synthetic leather with acid dyes, followed by washing and drying.

[0048] Please see Figures 2-5 The present invention also provides a preparation apparatus for random dyeing hard microfiber leather, including a mixing chamber 101, two feed pipes 102, a discharge pipe 103, two sets of weighing units, a melt spinning machine 104, and a stirrer 105. The two feed pipes 102 are both connected to the mixing chamber 101 and are both located above the mixing chamber 101. The melt spinning machine 104 is located on one side of the mixing chamber 101. The two ends of the discharge pipe 103 are respectively connected to the mixing chamber 101 and the melt spinning machine 104. The stirrer 105 is disposed on the mixing chamber 101. Each set of weighing units is respectively connected to the corresponding feed pipe 102.

[0049] In this embodiment, the two sets of weighing units respectively weigh and feed nylon 6 and low-density polyethylene raw materials. The raw materials are fed into the mixing box 101 through the corresponding feed pipe 102. The stirrer 105 stirs and mixes the two raw materials entering the mixing box 101. After the mixture is completed, the material is transported to the melt spinning machine 104 through the discharge pipe 103 for melt spinning to obtain ultrafine fibers.

[0050] Further, the weighing unit includes a weighing box 106, a movable plate 107, a weight sensor 108, a spring 109, a locking block 110, and an electric push rod 111. The weighing box 106 is fixedly connected to the feed pipe 102 and is located above the feed pipe 102. The movable plate 107 is rotatably disposed within the weighing box 106. The two ends of the spring 109 are respectively connected to the weighing box 106 and the movable plate 107. The weight sensor 108 is fixedly connected to the movable plate 107 and is embedded in the movable plate 107. The weighing box 106 has a groove 112. The locking block 110 is movably disposed within the groove 112. The electric push rod 111 is fixedly connected to the weighing box 106 and is located on the outer side wall of the weighing box 106. The output end of the electric push rod 111 is connected to the locking block 110.

[0051] In this embodiment, the raw material falls onto the movable plate 107 inside the weighing box 106. The weight sensor 108 collects the weight of the material on the movable plate 107 in real time. When the material reaches the set weight, the electric push rod 111 drives the locking block 110 to move into the groove 112, releasing the limiting lock on the movable plate 107. At this time, the movable plate 107 rotates under the action of the material's gravity, and the material is discharged downward through the feed pipe 102 into the mixing box 101. After the material is unloaded, the spring 109 pulls the movable plate 107 to reset, completing a single quantitative weighing and feeding, ensuring the accuracy of the feeding ratio of nylon 6 and low-density polyethylene.

[0052] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0053] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A method for preparing randomly dyed hard microfiber leather, characterized in that, Includes the following steps: Nylon 6 and low-density polyethylene are mixed in a mass ratio of 4~6:6~4 and melt-spun to produce ultrafine fibers with linear densities of 3~6 dB and 13~16 dB. The ultrafine fibers with a linear density of 3-6 dBT are mixed with ultrafine fiber threads with a linear density of 13-16 dBT and then needle-punched to form nonwoven fabric. Low-density polyethylene is incompletely extracted from polyurethane resin with a high elastic modulus by solvent toluene, and then oiled and dried to obtain a preform. The base material is coated with three resin layers with different color development effects, dried, and then dyed and finished to obtain random-dyed hard microfiber synthetic leather.

2. The method for preparing random-dyed hard microfiber leather as described in claim 1, characterized in that, In the step of impregnating a polyurethane resin with a high elastic modulus, incompletely extracting low-density polyethylene with toluene as a solvent, and then oiling and drying it to obtain a preform: The resin with high elastic modulus is prepared by reacting N,N-diphenylmethane diisocyanate, ethylene terephthalate, polytetrahydrofuran polyol and ethylene glycol.

3. The method for preparing random-dyed hard microfiber leather as described in claim 1, characterized in that, In the process of coating the base material with three resin layers that have different color development effects, drying, and then performing dyeing and finishing processes to obtain random-dyed hard microfiber synthetic leather: The three resin layers with different color development effects include resin SX-1125a, resin SX-1125b, and resin SX-1125c.

4. The method for preparing random-dyed hard microfiber leather as described in claim 3, characterized in that, The resin SX-1125a is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol and ethylene glycol.

5. The method for preparing random-dyed hard microfiber leather as described in claim 3, characterized in that, The resin SX-1125b is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol, ethylene glycol adipate, and ethylene glycol.

6. The method for preparing random-dyed hard microfiber leather as described in claim 3, characterized in that, The resin SX-1125c is prepared by reacting N,N-diphenylmethane diisocyanate, polytetrahydrofuran polyol, polycaprolactone polyol and 1,4-butanediol.

7. The method for preparing random-dyed hard microfiber leather as described in claim 1, characterized in that, In the process of coating the base material with three resin layers that have different color development effects, drying, and then performing dyeing and finishing processes to obtain random-dyed hard microfiber synthetic leather: The dyeing and finishing process involves dyeing hard microfiber synthetic leather with acid dyes, followed by washing and drying.

8. An apparatus for preparing random-dyed hard microfiber leather, applied to the method for preparing random-dyed hard microfiber leather as described in claim 1, characterized in that, The device includes a mixing chamber, two feed pipes, a discharge pipe, two sets of weighing units, a melt spinning machine, and a stirrer. Both feed pipes are connected to the mixing chamber and are located above it. The melt spinning machine is located on one side of the mixing chamber. The two ends of the discharge pipe are connected to the mixing chamber and the melt spinning machine, respectively. The stirrer is mounted on the mixing chamber. Each set of weighing units is connected to the corresponding feed pipe.

9. The apparatus for preparing random-dyed hard microfiber leather as described in claim 8, characterized in that, The weighing unit includes a weighing box, a movable plate, a weight sensor, a spring, a locking block, and an electric push rod. The weighing box is fixedly connected to the feed pipe and located above the feed pipe. The movable plate is rotatably disposed within the weighing box. The two ends of the spring are respectively connected to the weighing box and the movable plate. The weight sensor is fixedly connected to the movable plate and embedded in the movable plate. The weighing box has a groove, and the locking block is movably disposed within the groove. The electric push rod is fixedly connected to the weighing box and located on the outer side wall of the weighing box. The output end of the electric push rod is connected to the locking block.

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