CN103074780B - Preparation method of thin ultrafine composite fiber artificial leather base cloth - Google Patents

Abstract

The invention discloses a preparation method of thin ultrafine composite fiber artificial leather base cloth. The method comprises the following steps that (1), unfigured sea-island staple fibers are carded, lapped, then superimposed with unfigured orange-section composite filament woven mesh cloth, and subjected to needle punching to form composite needle-punched non-woven fabric of which the surface is covered with the woven mesh cloth; the composite needle-punched non-woven fabric is impregnated in a DMF (dimethyl formamide) solution of polyurethane; (2), solidifying and foaming treatment are conducted in a solidified DMF aqueous solution; (3), water washing is conducted; (4), LDPE (low-density polyethylene) in the composite needle-punched non-woven fabric is dissolved out with methylbenzene; (5), drying and shape forming are conducted; and (6) splitting is conducted; two layers of ultrafine fiber artificial leather base cloth are obtained; one layer is the thin ultrafine composite fiber artificial leather base cloth containing the unfigured orange-section composite filament mesh cloth; and the other layer is the conventional ultrafine fiber artificial leather base cloth. The obtained thin ultrafine composite fiber artificial leather base cloth has very good tensile strength and tearing strength due to the fact that the base cloth contains continuous orange-section fibers.

Description

Preparation method of thin composite superfine fiber artificial leather base cloth

technical field

The invention belongs to the artificial leather manufacturing technology, and relates to a method for manufacturing an artificial leather base cloth, and a preparation method for a thin composite superfine fiber artificial leather base cloth.

Background technique

The microfiber artificial leather base cloth is made by impregnating the sea-island short-fiber non-woven fabric in DMF (dimethylformamide) solution of polyurethane, and then soaking in the aqueous solution of coagulation liquid DMF for coagulation and foaming treatment, and then using It is produced by dissolving the "sea" part of the island-in-the-sea short fiber with inorganic or organic solvents. The island-in-the-sea staple fiber production methods used include fixed island method and indeterminate island method. Island-in-the-sea staple fibers produced by island-fixing method are melted by two kinds of polymers PA6 (nylon 6) and COPET (alkali-soluble polyester chip) respectively through a twin-screw compound spinning machine, and enter the island-in-sea spinning assembly, the island phase and the sea phase Converge and spray at the exit of the spinneret hole through their respective paths to form fixed-island sea-island fibers. The island phase and sea phase are continuous and evenly distributed in the length direction of the fiber, and the number of islands is fixed, generally more than 37 islands . Island-in-the-sea staple fibers are produced by the island-indefinite method. Nylon chips PA6 and LDPE (low-density polyethylene) are commonly mixed at a certain temperature and condition, melted and blended by the same screw extruder, and then sprayed by metering pumps and spinning components. The microfibers that form indeterminate islands have discontinuous island phases and are not fixed. The non-woven fabric formed by the sea-island fiber adopts the needle-punching process, and the non-woven fabric formed in this way is then ironed, impregnated, washed, extracted, washed and dried to form a superfine fiber artificial leather base cloth, and the thickness is generally 1.0mm. ~2.5mm. For thin microfiber artificial leather base fabrics (thickness 0.3mm-0.8mm) such as those used for clothing, golf gloves, and vehicles, the sheeting process is usually used, that is, the leather base cloth is divided into two pieces with a sheeting machine. For example, the superfine fiber artificial leather base cloth sheet with a thickness of 2.0mm is made into a superfine fiber artificial leather base cloth with a thickness of 0.5mm and 1.5mm. After the sheeted superfine fiber artificial leather base cloth, the collusion formed by needle punching inside the leather base is destroyed. The physical properties such as tear strength are relatively low, and it is difficult to produce a series of products such as high-grade thin garment leather with a thickness of 0.30-0.50mm that meets the physical properties.

Segmented orange composite fiber is a split composite fiber composed of two polymers with different properties, PET and PA6. Its cross section is composed of lobes similar to "orange". There is a certain compatibility between the two polymers with different properties to ensure the normal process of spinning and post-processing, but there are differences in properties, which can be compounded by chemical or physical methods during the fabric treatment process. The fibers split into microfibers. Using this form of fiber cross-section, "orange segment" ultrafine fibers can be obtained after stripping. This segmented segmented composite fiber is usually divided into 6+6 or 8+8 types, that is, it consists of 6 petals (or 8 petals) ) PET and 6 petals (or 8 petals) PA6 are separated from each other to form orange petals. The weight ratio of the two components can be 15/85-85/15, and the ultra-fine fiber with a linear density of 0.10-0.50 dtex can be finally obtained. Because the petals of the segmented orange composite fiber are connected to each other, sometimes the peeling is not good, which easily causes problems such as poor dyeing of the superfine fiber fabric. The way to improve the poor peeling is to make rice-shaped composite fibers. The cross-section of the rice-shaped composite fiber is composed of a polymer that forms a "rice"-shaped skeleton and another polymer that is a wedge between the "rice"-shaped skeleton. If the proportion of the "rice"-shaped skeleton is less than 15%, the skeleton is too thin and uneven, which will also increase the difficulty of peeling; if the proportion of the "rice"-shaped skeleton is greater than 50%, the skeleton becomes very thick and will form after peeling A thicker fiber that affects the softness of microfiber fabrics. The "rice" type composite fiber is also called "N+1" type, which is composed of N petals plus a "rice" type. When N is greater than 12, finer fibers will be obtained, but there will be problems that the skeleton is too thin and uneven, and it is difficult to peel off.

Contents of the invention

The invention aims to provide a method for preparing a thin composite ultrafine fiber artificial leather base cloth, and the obtained thin composite ultrafine fiber artificial leather base cloth has higher physical properties.

The preparation method of this thin composite microfiber artificial leather base cloth comprises the following steps:

(1) impregnating the composite needle-punched non-woven fabric in the DMF solution of polyurethane;

(2) Soak the semi-finished product obtained in step (1) in an aqueous solution of coagulation liquid DMF, carry out coagulation and foaming treatment, and polyurethane is made into an elastomer containing microcellular cells;

(3) washing with water;

(4) dissolve the LDPE part in the composite needle-punched nonwoven fabric with toluene;

(5) drying and setting;

(6) sheet skin, obtains two-layer microfiber artificial leather base cloth;

Wherein the composite needle-punched non-woven fabric described in the step (1) is that the indeterminate island-in-the-sea short fiber is laminated with the indeterminate island orange segment composite filament weaving mesh cloth after carding, and the weaving mesh cloth is on the surface layer, The indeterminate island-in-the-sea short fibers are compounded with the woven mesh cloth by acupuncture to form a composite needle-punched non-woven fabric covered with a woven mesh cloth; the two-layer superfine fiber artificial leather base cloth obtained by the step (6) sheet skin Among them, one layer is a thin composite superfine fiber artificial leather base cloth containing indeterminate island orange segment composite filament woven mesh cloth, and the other layer is a conventional superfine fiber artificial leather base cloth. The manufacture method of the indeterminate island segmented orange type composite filament described in the step (1) is to apply twin-screw compound spinning equipment, adopt segmental segmented segmental compound spinning method, make PA6+LDPE blended phase and PA6 or PET respectively It is melted by the screw, and then merged by the segmental-shaped composite spinning plate to form N+1 shape at the entrance of the spinneret hole. The filaments are extruded together, cooled, oiled, and wound to make semi-finished UDY filaments, and then stretched. Made into finished product DT or made into DTY indeterminate island orange segment composite filament through stretching and deformation, in which, PA6+LDPE blended melt forms a "rice" shape, and in the "rice" part, the indeterminate island group The mixing ratio of PA6 and marine LDPE is between 40:60 and 60:40; N slices are PA6 or PET.

The thin superfine fiber artificial leather base cloth prepared by the preparation method of this thin composite superfine fiber artificial leather base cloth contains the woven mesh cloth made of indeterminate island orange segment composite filaments, and the " "Piece of orange" fibers are continuous, which effectively increases the strength of the cloth surface, has high physical properties, and has good tensile strength and tear strength.

Description of drawings

Fig. 1 is the sectional photo of indeterminate island segmental orange type composite filament;

Fig. 2 is a cross-sectional photo of the segmental composite filament of Adventitia Island after the LDPE marine phase component is dissolved;

Fig. 3 is the preparation process flow chart of thin compound microfiber artificial leather base cloth;

Fig. 4 is the production process flow chart of indeterminate island segmental orange type composite UDY filament;

Fig. 5 is a flow chart of the production process for processing DT filaments from orange segmented composite UDY yarns in Indeterminate Island.

Detailed ways

As shown in Figure 3, the preparation method of this thin composite superfine fiber artificial leather base cloth comprises the following steps:

(1) After combing and laying the web of Adventitia sea-island short fiber, it is laminated with Adventitia orange petal-shaped composite filament woven mesh. Cloth compounding to form a composite needle-punched non-woven fabric covered with a woven mesh cloth, and impregnate the composite needle-punched non-woven fabric in a DMF solution of polyurethane;

(2) Soak the semi-finished product obtained in step (1) in an aqueous solution of coagulation liquid DMF, carry out coagulation and foaming treatment, and polyurethane is made into an elastomer containing microcellular pores;

(3) washing with water;

(4) Use toluene to dissolve the LDPE part of the adventitious island-in-the-sea short fiber and the adventitious island orange segment composite filament in the composite needle-punched nonwoven fabric;

(5) drying and setting;

(6) sheet skin, obtains two-layer microfiber artificial leather base cloth, and one of them is the thin compound superfine fiber artificial leather base cloth that contains indeterminate island orange petal type composite filament woven mesh cloth, and another layer is conventional Microfiber faux leather base fabric.

In the preparation method of this thin composite superfine fiber artificial leather base cloth, the manufacturing method of the indeterminate island segmental orange type composite filament described in the (1) step is as shown in Figure 4, uses twin-screw composite spinning equipment, adopts Piece-shaped composite spinning method, the blended phase of PA6+LDPE and PET are melted by their respective screws, and then merged at the entrance of the spinneret hole through the composite spinning plate of Piecelet-shaped, distributed into N+1 shape, and extruded together After cooling, oiling and winding, semi-finished UDY yarn (undrawn yarn) is made; as shown in Figure 5, UDY yarn is stretched to make finished DT (drawn yarn), or stretched and deformed. It is made into DTY (stretched yarn) adventitious island orange segment composite filament.

In the preparation method of this thin composite superfine fiber artificial leather base cloth, in the preparation method of the indeterminate island segmented orange-shaped composite filament, a "rice" font can be formed by blending PA6+LDPE, " In the "m"-shaped part, the mixing ratio of the indeterminate island component PA6 and the marine LDPE is between 40:60 and 60:40; the N orange segment components are PA6 or PET.

In the preparation method of this thin compound superfine fiber artificial leather base cloth, when the segmental segmental phase in the described indeterminate island segmental segmental composite filament manufacturing method is PA6, the melt temperature control of segmental segmental component during spinning At 270-280°C, the melt temperature of the character "米" is controlled at 265°C-285°C.

In the preparation method of this thin composite microfiber artificial leather base cloth, when the segmental segmental phase in the described indeterminate island segmental segmental composite filament manufacturing method is PET, the melt temperature control of segmental segmental component during spinning At 280-290°C.

The preparation method of this thin composite microfiber artificial leather base cloth has the following advantages:

(1) Applying PA6+LDPE blending as a component of the "rice"-shaped skeleton to the production of segmented segmented composite filaments can improve the fineness distribution of ultrafine fibers in segmental segmented segmental composite filaments. Up to 0.001dtex, the cross-section of a single fiber is shown in Figure 1. The LDPE in the PA6+LDPE blend phase is dissolved with an organic solvent, and the "rice"-shaped skeleton can be effectively opened, leaving the adventitious island microfiber component PA6 and the "orange segment" component PET in the other phase , its cross-section is shown in Figure 2, which effectively solves the problem of fiber opening; after the PE is drawn out, the monofilament fineness of the left indeterminate island PA6 fiber is 0.001-0.30dtex; 0.50dtex.

(2) Since the thin microfiber artificial leather base fabric obtained from the sheet contains mesh cloth woven from indeterminate island orange-shaped composite filaments, the "orange-shaped" PET in the mesh filaments is continuous, which effectively increases the fabric thickness. The strength of the surface, so that the thin microfiber artificial leather base cloth with a thickness of 0.30mm-0.50mm has high physical properties, and has good tensile strength and tear strength.

(3) When the mass ratio of the blended phase of LDPE and PA to PET is 30:70, the proportion of the island component in the indeterminate island orange segment composite filament of the mesh can be significantly increased, up to about 85%, so that the required The extracted PE is correspondingly reduced, the production cost is reduced, and the physical properties of the prepared superfine fiber artificial leather base cloth are improved.

(4) When the proportion of the island component in the indeterminate island orange segment composite filament in the mesh is as high as about 85%, the surface density of the thin superfine fiber artificial leather base cloth increases significantly, and the mesh filament "meter" The PA6 island phase fiber in the font skeleton is similar to the PA6 island phase fiber in the PA6/LDPE indefinite island staple fiber, and they are integrated into one, thus forming the delicate touch and dense appearance of the thin superfine fiber artificial leather base fabric, which can effectively cover up The traces of the cloth pattern of the woven mesh fabric will make the suede feel more delicate and uniform when making suede products.

In the preparation method of this thin composite superfine fiber artificial leather base cloth, in the manufacture of the indeterminate island orange segment composite filament, the "rice" shape can use low-density polyethylene LDPE with a melt index of 40-60MFI and a relative viscosity. It is a blend of nylon PA6 with a relative viscosity of 2.6-3.2η, and the segmented segment uses nylon PA6 with a relative viscosity of 2.6-3.0η or PET with a viscosity of 0.640dl/g.

Example 1

Preparation of Garment Leather Base Fabric

1: Spinning process of PA6/(PA6+LDPE) indeterminate island orange segment composite filament

(a) Raw material for spinning:

Piece-shaped component: PA6 chips, grade M32800, relative viscosity is 2.8η;;

Blend of LDPE+PA6: a blend of LDPE with a melt index of 50MFI and PA6 with a viscosity of 2.8η, wherein:

LDPE, grade MB9500, melt index is 50.

Nylon chips, grade M32800, relative viscosity is 2.8η;

(b) Raw material ratio: weight ratio: PA6/(LDPE+PA6)=50/(25+25)

(c) Spinneret specifications: number of holes × number of orange segments × aperture is 48 × (8+1) × 0.30mm;

(d) Screw extruder: specifications

(e) Metering pump specification: 0.6cc/rev;

(f) Cooling air temperature: 16°C, wind speed: 0.6m/s;

(g) Rotational speed of the oil pan: 26rpm/min, oil concentration: 3.0%;

(h) Spinning (winding) speed: 450m/min;

(i) Spinning process and physical properties:

Table 1.1528dtex/48×(8+1)F UDY indeterminate island orange petal type composite filament spinning process table

Table 1. Physical property test data of 2528dtex/48×(8+1)F UDY indeterminate island orange segment composite filament

Specification Breaking strengthcn/dtex Elongation at break% Oil content% 528dtex/48×(8+1)F 1.21 354.6 1.12

(j) Stretching process and physical properties:

Stretching process settings: the effective stretching ratio is 3.3, the temperature of the hot plate is 75°C, the temperature of the hot box is 90°C, and the stretching speed is 200m/min.

Table 1.3 Physical property test data of DT yarn after stretching and the number of superfine fibers in the section of single yarn

2: Preparation of composite microfiber artificial leather base cloth

The 50g/ ^m2 woven mesh fabric woven with PA6/(PA6+LDPE) indeterminate island orange segment composite filaments is covered on the surface layer of the indeterminate island sea island short fiber cotton net that has been carded and laid, and then compounded by needle punching. , to form a composite non-woven fabric with a total unit weight of 650g/ ^m2 covered with a woven mesh cloth, which is impregnated with polyurethane, and the LDPE in the blend phase of PA6 and LDPE is dissolved with an organic solvent to obtain a superfine non-woven fabric with a thickness of 1.5mm. Fiber artificial leather base fabric; the base fabric is peeled by a sheeting machine to obtain a 0.35mm upper and lower two-layer superfine fabric layer containing indeterminate island orange petal type composite filament woven mesh layer and 1.15mm ordinary indefinite island fiber cotton net Fiber faux leather base fabric.

Since the 0.35mm superfine fiber artificial leather base fabric contains woven mesh made of indeterminate island orange-shaped composite filaments, the "orange-shaped" PA6 in the mesh filaments effectively increases the strength of the fabric surface, making the base fabric It has high physical properties; the proportion of microfibers extracted from PE fibers is 75%, so the density of the obtained thin microfiber artificial leather base cloth is increased, and its strength is more effectively enhanced; the microfibers in the indeterminate island part are It enhances the delicate touch and dense elasticity of the product. After napping processing, it can be made into high-grade artificial suede with high density, high-grade suede feel and "writing effect", or veneer processing to obtain imitation leather garment leather, etc.

The physical properties of the 0.35mm composite superfine fiber artificial leather base cloth are compared with those of the ordinary indeterminate island PA6 microfiber base cloth as shown in the following table:

Table 1.4 (after skin treatment) comparison of physical properties of 0.35mm garment leather base fabrics

This kind of 0.35mm superfine fiber artificial leather base fabric containing indefinite island orange petal type composite filament mesh cloth has obvious improvement in strength and tearing, and the suede or artificial leather made of surface can be used directly. It is used as the main fabric of clothing, while the ordinary microfiber base cloth with a specification of 0.35mm can only be used as clothing accessories due to its low physical properties.

Example 2

Preparation of leather base cloth for automobiles

1: Spinning process of PET/(PA6+LDPE) indeterminate island orange segment composite filament

(a) Raw material for spinning:

Portion-shaped component: PET chip, viscosity is 0.64dl·g ^-1 ;

Blend of LDPE+PA6: a blend of LDPE with a melt index of 50MFI and PA6 with a viscosity of 2.8η, wherein:

LDPE, grade MB9500, melt index is 50, produced by Korean LG company.

Nylon chips, grade M32800, relative viscosity is 2.8η;

(b) Raw material ratio: weight ratio: PET/(LDPE+PA6)=60/(20+20);

(c) Spinneret specifications: number of holes × number of orange segments × aperture is 48 × (8+1) × 0.30mm;

(d) Screw extruder: specifications

(e) Metering pump specification: 0.6cc/rev;

(f) Cooling air temperature: 18°C, wind speed: 0.6m/s;

(g) Rotational speed of the oil pan: 26rpm/min, oil concentration: 3.0%;

(h) Spinning (winding) speed: 450m/min;

(i) Spinning process and physical properties:

Table 2.1528dtex/48×(8+1)F UDY orange petal type composite filament spinning process table

Table 2. Physical property test data of 2528dtex/48×(8+1)F UDY segmented orange composite filament

Specification Breaking strengthcn/dtex Elongation at break% Oil content% 165dtex/48×(8+1)F 1.27 321.6 1.13

(j) Stretching process and physical properties:

Stretching process settings: the effective stretching ratio is 3.2, the temperature of the hot plate is 75°C, the temperature of the hot box is 90°C, and the stretching speed is 200m/min.

Table 2.3 Physical property test data of DT yarn after stretching and the number of superfine fibers in the section of single yarn

2: Preparation of composite microfiber artificial leather base cloth

The 60g/ ^m2 woven mesh cloth woven with the adventitious island orange segment composite filament is covered on the surface layer of the adventitious island sea island type staple fiber cotton net through carding and laying, and then compounded by needle punching to form a surface covered with organic fabric. The composite non-woven fabric with a total unit weight of 850g/ ^m2 of the woven mesh cloth is impregnated with polyurethane, and the LDPE in the blend phase of PA6 and LDPE is dissolved with an organic solvent to obtain a superfine fiber artificial leather base cloth with a thickness of 2.0mm The base cloth is peeled by a sheeting machine to obtain a 0.80mm upper and lower two-layer superfine fiber artificial leather base cloth containing an indeterminate island orange petal type composite filament mesh cloth layer and a 1.20mm ordinary indeterminate island sea island type fiber cotton net .

Because the 0.80mm superfine fiber artificial leather base fabric contains mesh made of indeterminate island orange-shaped composite filaments, the "orange-shaped" PET in the mesh filaments effectively increases the strength of the fabric surface, making the base fabric It has higher physical properties; compared with ordinary PA6 microfiber base fabric, because of the good rigidity of PET fiber and small elongation at break, the base fabric has good thermal stability and is not easy to deform. It is an excellent car leather material. The comparison of the physical properties of the composite microfiber artificial leather base fabric with that of the ordinary indeterminate island PA6 microfiber base fabric is shown in the following table:

Table 2.4 (After skin treatment) Comparison of physical properties of 0.80mm automotive leather base fabrics

Compared with the common microfiber base cloth of the same kind, the composite microfiber artificial leather base cloth containing mesh cloth has 50%-60% higher strength and tearing. The elongation at break and the heat shrinkage rate at 150° C. for 5 minutes of the base fabric decreased by about 40%, and the thermal stability of the automotive leather base fabric was significantly improved.

Claims (3)

1. a preparation method for slim composite superfine fiber artificial leather base fabric, comprises the following steps:

(1) composite needle nonwoven fabric is flooded in the DMF of polyurethane solution;

(2) (1) step gained semi-products are soaked in the aqueous solution of solidification liquid DMF, solidify and the processing of foaming, polyurethane is made to the elastomer that contains microvesicle hole;

(3) washing;

(4) with toluene, dissolve the LDPE part in composite needle nonwoven fabric;

(5) dry, setting;

(6) split, obtains two-layer superfine fiber artificial leather base fabric;

It is characterized in that the composite needle nonwoven fabric described in (1) step is that to weave screen cloth superimposed with indefinite island tangerine lobe type bicomponent filament yarn after combing lapping by indefinite island fabric of island-in-sea type staple fibre, weave screen cloth on top layer, by acupuncture, make indefinite island fabric of island-in-sea type staple fibre again and to weave screen cloth compound, form surface and be covered with the composite needle nonwoven fabric of weaving screen cloth, in the two-layer superfine fiber artificial leather base fabric of (6) step split gained, one deck is to contain the slim composite superfine fiber artificial leather base fabric that indefinite island tangerine lobe type bicomponent filament yarn is weaved screen cloth, and another layer is conventional superfine fiber artificial leather base fabric, the manufacture method of the indefinite island tangerine lobe type bicomponent filament yarn described in (1) step is, application twin-screw composite spinning equipment, adopt tangerine lobe type composite spinning method, make PA6+LDPE blend phase and PA6 or PET respectively through screw rod melting, through tangerine lobe type Compound spinning filament plate, merge in spinneret orifice porch and be scattered in N+1 shape, together extrude tow, through cooling, oil, coiling is made semi-finished product UDY silk, drawn is made the distortion of finished product DT or drawn and is made the indefinite island of DTY tangerine lobe type bicomponent filament yarn again, wherein, PA6+LDPE blend is melted body and is formed 1 " rice " font, in " rice " font part, the mixed proportion of indefinite island component PA6 and marine facies LDPE is that 40:60 is between 60:40, N tangerine lobe shape is PA6 or PET.

2. the preparation method of slim composite superfine fiber artificial leather base fabric as claimed in claim 1, it is characterized in that in the manufacture method of described indefinite island tangerine lobe type bicomponent filament yarn, tangerine lobe is PA6 mutually, during spinning, the melt temperature of tangerine lobe component is controlled at 270～280 ℃, and the melt temperature of " rice " word phase is controlled at 265 ℃～285 ℃.

3. the preparation method of slim composite superfine fiber artificial leather base fabric as claimed in claim 1, it is characterized in that in the manufacture method of described indefinite island tangerine lobe type bicomponent filament yarn, tangerine lobe is PET mutually, during spinning, the melt temperature of tangerine lobe component is controlled at 280～290 ℃, and the melt temperature of " rice " word phase is controlled at 265 ℃～285 ℃.