A method for preparing sandwich flakes

Abstract

The present invention relates to the technical field of flakes, and it relates to a method for preparing sandwich flakes. A blank composed of a solid fiber layer, a first hollow fiber layer and a second hollow fiber layer arranged on its upper and lower end surfaces is placed on a reel, and the blank is transmitted to a reel through a transmission roller group. During this period, the blank passes through a drying unit, and a plurality of needle tubes are inserted into the interior of the blank to blow hot air into the interior of the blank until the hot air melts the fibers inside the blank and adheres and fixes them to form. The needle tube of the present invention is inserted into the interior of the formed blank, and the depth of the needle tube outlet in the blank is controlled to achieve heating at different positions, thereby ensuring the stability of the flakes after forming.

Description

Technical Field

[0001] The present invention relates to the technical field of flakes, and more particularly to a method for preparing sandwich flakes. Background Art

[0002] Spray-bonded cotton batting is an ideal filling material for winter clothing, bedding, and furniture because of its high fluffy texture, high compression resilience, dry-resistance, washability, flatness, light weight, and warmth. Currently, spray-bonded cotton batting is primarily made from staple fibers. Fibers of varying lengths, finenesses, and functionalities are thoroughly blended, carded, and formed into a web. Layers of cotton are stacked to a desired thickness or weight, sprayed with adhesive, and heat-treated.

[0003] For example, existing cotton-padded clothes are filled with wadding inside the lining to achieve the effect of keeping warm. However, the existing cotton-padded clothes have poor resilience after compression. After being washed, compressed and other treatments, they will lose a certain thickness and elasticity, causing the cotton to shrink, further affecting the heat preservation and fluffiness of the cotton-padded clothes.

[0004] For example, CN210856543U discloses a highly efficient thermal insulation aerogel fiber flake. The fiber flake comprises a random mixture of aerogel fibers, thermal insulation fibers, and resilient support fibers. This technical solution provides a flake with high thermal insulation, high lightness, fluffiness, and softness, high air permeability, and strong odor filtration and absorption capabilities.

[0005] The above-mentioned prior art adopts the method of stacking and fixing multiple layers of fibers. The current method of fixing multiple layers of fibers is a thermal insulation sheet and its preparation method and application disclosed in CN117071179A, which sprays adhesive on the end faces of the laminated layers to be in contact, and then bonds the two adjacent fiber layers with the adhesive, and then fixes the two by standing and then drying.

[0006] Another method is to use hot air processing to allow hot air to penetrate the fiber web so that, for example, ES fibers are melted as heat-bonding fibers, thereby generating adhesion between the fiber layers.

[0007] In the above-mentioned existing preparation process, when the hollow fiber layer and the solid fiber layer are combined, if an adhesive is used, the adhesive will penetrate into the channels of the middle fiber, causing the channels to close, affecting its structural performance, and thus reducing the fluffiness of the flakes. Therefore, the use of hot air combined with ES fiber material is the best, but this method also has a disadvantage. When the hollow fiber layer is fixed on both sides of the solid fiber layer, the current hot air penetration direction is as follows: Figure 1First, the back hollow fiber layer is placed on the base surface, and then the solid fiber layer is covered on the back hollow fiber layer in turn, and the front hollow fiber layer is covered on the solid fiber layer. After the three are squeezed and rolled, they are unfolded. After the hot air passes through the front hollow fiber layer, the solid fiber layer and the back hollow fiber layer in turn through the drying equipment, the ES fiber on the solid fiber layer is melted, and the front and back hollow fiber layers are fixed. When the hot air penetrates the front hollow fiber layer to blow air, the wind force and temperature it receives are the highest, followed by the back hollow fiber layer. Therefore, the heating of the front hollow fiber layer and the back hollow fiber layer is uneven, which will result in a lot of heat waste in the process. This heating method causes the finished product to have unstable thermal connection during use, resulting in drilling and running of the flocs, which will affect the shrinkage and recovery performance of the flocs and its thermal insulation properties.

[0008] In view of the above, a new sandwich-type combination process for hollow fibers and other solid fibers is currently needed. Summary of the Invention

[0009] In view of the shortcomings of the prior art, the object of the present invention is to provide a preparation method for improving the stability of flakes and preventing the fiber layers in the flakes from falling off at the joints.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] A method for preparing a sandwich flake, comprising the following specific steps:

[0012] A blank consisting of a solid fiber layer followed by a first hollow fiber layer and a second hollow fiber layer arranged on its upper and lower ends is placed on an unwinder, and the blank is transferred to a winder via a transfer roller group. During this period, the blank passes through a drying unit, in which a plurality of needles are inserted into the blank to blow hot air into it until the hot air melts the fibers inside the blank and fixes them together to form a shape.

[0013] The present invention is further configured such that when the blank passes through the transmission roller group, two adjacent continuous rollers are staggered so that the upper and lower end surfaces of the blank respectively contact the two rollers.

[0014] The present invention is further configured as follows: in the drying unit, there are two dryers, which are respectively placed on both sides of the blank. When the dryers dry the blank, the needle tubes on the ends of the two dryers are respectively inserted into the interior of the blank from the end faces of both sides of the blank, and an air outlet for hot air output is provided on the needle tube near its end.

[0015] The present invention is further configured as follows: the steps of drying the blank by the dryer are as follows:

[0016] S1. Preheating the blank:

[0017] S11, the head control needles of the two dryers are respectively inserted into the first hollow fiber layer and the second hollow fiber from the two end surfaces of the blank, and the air outlet is placed at the 1 / 2 position in the thickness direction of the first hollow fiber layer and the second hollow fiber layer. The dryers output hot air to preheat the first hollow fiber layer and the second hollow fiber layer. The preheating temperature is 65-80 degrees and the preheating time is 20-30 seconds.

[0018] S12. The needles of the two dryers are controlled to extend toward the solid fiber layer so that the air outlet is located at 1 / 2 of the thickness of the solid fiber layer. The dryers output hot air to preheat the solid fiber layer. The preheating temperature is 90-110 degrees and the preheating time is 30-40 seconds.

[0019] S2. Heating the blank: After step S12, the air outlet of the dryer's head control needle tube is placed at the intersection, which is the intersection between the solid fiber layer and the first hollow fiber layer, and the intersection between the solid fiber layer and the second hollow fiber layer. The dryer outputs hot air, and the hot air continues to heat up from 125 degrees to 150 degrees, and the heating time is 5 minutes.

[0020] The present invention is further configured such that after the needle tubes of the two dryers are inserted into the blank, the needle tubes are arranged in a front-to-back continuous manner so as to cover the drying area of ​​the blank.

[0021] The present invention is further configured as follows: the end of the needle tube has a pointed portion, the needle tube is hollow, and a plurality of air outlets are opened around the outer peripheral wall of the needle tube.

[0022] The present invention is further configured such that the spacing between two adjacent rows of needle tubes is 8 cm.

[0023] The present invention is further configured such that: convex patterns are provided on the outer peripheral wall of the roller.

[0024] Compared with the shortcomings of the prior art, the beneficial effects of the present invention are:

[0025] The needle is inserted into the interior of the blank and the depth of the needle outlet is controlled to achieve heating at different locations, thus ensuring the stability of the flakes after forming. It can also further increase the fluffiness of the outer layer of the flakes, thereby ensuring shrinkage recovery performance.

[0026] The entire processing process is simple and the control method is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a processing flow chart of the present invention;

[0028] Figure 2 It is a structural schematic diagram of the drying unit of the present invention;

[0029] Figure 3 It is a structural schematic diagram of the needle tube of the present invention. DETAILED DESCRIPTION

[0030] Reference Figures 1 to 3 The embodiments of the present invention are further described.

[0031] Sandwich-type flakes: The flakes are composed of a solid fiber layer and two hollow fiber layers, wherein the solid fiber layer includes a composite short fiber layer and a thin ES fiber layer placed on both sides thereof. The first hollow fiber layer and the second hollow fiber layer are respectively covered on the two end surfaces of the solid fiber layer, that is, the end surfaces containing the ES fiber layer. The melting point of ES fiber is 130°. It will melt when heated, and serve to bond and fix the two hollow fiber layers and the solid fiber layer. This is a conventional production method in the prior art.

[0032] The preparation method of the present invention is as follows:

[0033] A barrel with a blank 11 composed of a solid fiber and a first hollow fiber and a second hollow fiber arranged on its upper and lower end surfaces is placed on the unwinder 1, and the blank is transferred to the winder 4 through the transfer roller group 2. During this period, the blank 11 passes through the drying unit. There are multiple needles 5 in the drying unit that are inserted into the blank and blow hot air into it until the hot air melts the inside of the blank 11 and then adheres and fixes it to take shape.

[0034] When the blank 11 passes through the transmission roller group 2, two adjacent continuous rollers are staggered so that the upper and lower end surfaces of the blank respectively contact the two rollers, and there are convex patterns on the outer peripheral walls of the two rollers.

[0035] The blank material must pass through a drying unit 3, which includes a frame 31 and two dryers (321, 322) placed on the frame. The two dryers (321, 322) are respectively placed on both sides of the blank material. When the dryers (321, 322) dry the blank material 11, the needle tubes 5 on the ends of the two dryers (321, 322) are respectively inserted into the interior of the blank material 11 from the end faces of both sides thereof, and an air outlet for hot air output is provided on the needle tube 5 near its end.

[0036] The dryers (321, 322) are movably connected to the frame 31. A motor 6 and a screw rod 61 for controlling the lifting of the dryer are installed on one side of the frame 31. There are two sets of motors 6 and screw rods 61, which correspond to the two dryers respectively. A slide rod 8 for sliding the dryer is provided on the other side of the frame. The screw rod is a ball screw.

[0037] One side of the dryer (321, 322) is movably connected to a screw rod 61, one end of the screw rod 61 is connected to a bearing seat, and the other end is connected to a motor 6. A connecting rod 7 is fixed on the side wall of the dryer, and the connecting rod 7 is fixed to a sliding sleeve on the screw rod.

[0038] A rod body is fixed on the other side of the dryer, and a sleeve is provided at the end of the rod body, which is sleeved on the slide rod 8.

[0039] Openings 30 are provided on both sides of the frame for the connecting rod and the rod body to move.

[0040] After the needle tubes 5 of the two dryers are inserted into the stock, they are arranged in a continuous front-to-back arrangement to cover the drying area of ​​the stock. The needle tubes of the two dryers are vertically staggered. When simultaneously inserted into the stock, the row of needle tubes of the lower dryer 322 is placed between two adjacent rows of needle tubes of the upper dryer 321. The spacing between adjacent rows of needle tubes is 8 cm. That is, when the needle tubes are inserted into the stock, the spacing between adjacent needle tubes is 4 cm.

[0041] The needle tube 5 has a pointed end and is hollow. Four air outlets 50 are provided around the outer wall of the needle tube. The four air outlets 50 are located in the four axial directions of the needle tube, namely, up, down, left, and right.

[0042] The steps of drying the blank in the dryer are as follows:

[0043] S1. Preheating the blank:

[0044] S11. The heads of the two dryers are driven by motors to control the needles to be inserted into the first hollow fiber layer and the second hollow fiber layer from both end surfaces of the blank, respectively. The air outlets are located at 1 / 2 of the thickness direction of the first hollow fiber layer and the second hollow fiber layer. The dryers output hot air to preheat the first hollow fiber layer and the second hollow fiber layer. The preheating temperature is 65-80 degrees and the preheating time is 20-30 seconds.

[0045] S12. The heads of the two dryers are driven by motors to control the needles to extend into the solid fiber layer so that the air outlet is located at 1 / 2 of the thickness of the solid fiber layer. The dryers output hot air to preheat the solid fiber layer. The preheating temperature is 90-110 degrees and the preheating time is 30-40 seconds.

[0046] S2. Heating the blank: After step S12, the air outlet of the dryer's head control needle tube is placed at the intersection, which is the intersection between the solid fiber layer and the first hollow fiber layer, and the intersection between the solid fiber layer and the second hollow fiber layer. The dryer outputs hot air, and the hot air continues to heat up from 125 degrees to 150 degrees, and the heating time is 5 minutes.

[0047] Example 1: The dryer outputs hot air to preheat the first hollow fiber layer and the second hollow fiber layer, the preheating temperature is 70 degrees, the preheating time is 25 seconds, and the dryer outputs hot air to preheat the solid fiber layer, the preheating temperature is 100 degrees, and the preheating time is 35 seconds.

[0048] Example 2: The dryer outputs hot air to preheat the first hollow fiber layer and the second hollow fiber layer, the preheating temperature is 65 degrees, the preheating time is 30 seconds, and the dryer outputs hot air to preheat the solid fiber layer, the preheating temperature is 90 degrees, and the preheating time is 40 seconds.

[0049] Example 3: The dryer outputs hot air to preheat the first hollow fiber layer and the second hollow fiber layer, the preheating temperature is 80 degrees, the preheating time is 20 seconds, and the dryer outputs hot air to preheat the solid fiber layer, the preheating temperature is 110 degrees, and the preheating time is 30 seconds.

[0050] Comparative Example 1: Without the preheating step, the air outlet of the dryer's head control needle tube is placed at the junction, the dryer outputs hot air, the dryer outputs hot air, the hot air temperature is 140 degrees, and the duration is 5 minutes.

[0051] Comparative Example 2: Without the preheating step, the air outlet of the dryer's head control needle tube is placed at the junction of each layer of the blank, the dryer outputs hot air, the dryer outputs hot air, the hot air temperature is 150 degrees, and the duration is 5 minutes.

[0052] Comparative Example 3: After the preheating condition of Example 3, the air outlet of the dryer's head control needle tube is placed at the junction of the blank layers, and the dryer outputs hot air. The dryer outputs hot air with a hot air temperature of 140 degrees and a duration of 5 minutes.

[0053] Comparative Example 4: After the preheating condition of Example 3, the air outlet of the dryer's head control needle tube is placed at the junction of the blank layers, and the dryer outputs hot air. The dryer outputs hot air with a hot air temperature of 150 degrees and a duration of 5 minutes.

[0054] The following performance tests were performed on the thermal insulation sheets provided in the examples and comparative examples:

[0055] Thermal insulation rate: tested in accordance with GB / T 35762-2017 standard;

[0056] Compression rebound rate: tested in accordance with FZ / T64003-2001 standard;

[0057] Washing size change rate: tested in accordance with FZ / T 60014-2017 standard;

[0058] The test results are shown in the following table:

[0059] Insulation rate Compression rebound rate Washing size change rate Example 1 78.7% 91.4% 17.5% Example 2 77.9% 90.3% 18.8% Example 3 81.6% 92.8% 13.6% Comparative Example 1 65.3% 76.2% 35.7% Comparative Example 2 66.5% 75.3% 37.6% Comparative Example 3 70.3% 79.4% 24.5% Comparative Example 4 72.2% 80.6% 23.8%

[0060] As shown in the above table,

[0061] The compression rebound rate of Examples 1-3 is ≥90%, which is a first-class product. The compression rebound rate of Comparative Examples 1-4 is ≥75%, which is a qualified product. The heat preservation rate of Examples 1-3 is ≥75%, and the thin strip change rate is ≤20%.

[0062] The heat preservation rate of comparative example 1-2 is close to 65%, and the washing size change rate is close to 36%.

[0063] The heat preservation rate of ratio 3-4 is higher than 70%, and the washing size change rate is close to 24%.

[0064] The difference between the two is whether the preheating method is adopted. The comparison of the data of ratio 3-4 with Example 3 shows that the continuous heating method of hot air can improve the performance of the product compared with the traditional fixed and stable heating.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a sandwich flake, characterized in that: The specific steps are as follows: The blank composed of the first hollow fiber layer and the second hollow fiber layer arranged on the upper and lower ends is placed on the unwinding machine. The blank is transferred to the winder through the transfer roller group. During this period, the blank passes through the drying unit. There are multiple blank inserts in the drying unit. A needle tube is inserted into the blank to blow hot air into it until the hot air melts the fibers inside the blank and fixes them together to form the blank. When the blank passes through the conveying roller group, two adjacent continuous rollers are staggered so that the upper and lower end surfaces of the blank are separated. Do not conflict with the two rollers. In the drying unit, there are two dryers, which are placed on both sides of the blank to dry When the machine is drying the blank, the needle tubes on the two ends of the dryer are inserted into the inside of the blank from the two sides of the blank. An air outlet for hot air output is provided near the end thereof. The end of the needle tube has a pointed portion and the needle tube is hollow. Several air outlets are provided around the outer wall of the needle tube. The steps of drying the blank in the dryer are as follows: S1, preheating the blank; S11, the two dryer heads control the needle tubes to insert into the first hollow fiber from both ends of the blank The air outlet is placed in the 1 / 2 position of the first hollow fiber layer and the second hollow fiber layer in the thickness direction. The dryer outputs hot air to preheat the first and second hollow fiber layers. The preheating temperature is 65-80 degrees. The interval is 20-30S; S12, the two dryer heads control the needle tubes to extend into the direction of the solid fiber layer so that the air outlet is placed at the thickness of the solid fiber layer. 1 / 2, the dryer outputs hot air to preheat the solid fiber layer. The preheating temperature is 90-110 degrees and the preheating time is 30-40 seconds. S2, heating the blank: after step S12, the air outlet of the dryer's head control needle tube is placed at the junction, which is The junction of the solid fiber layer and the first hollow fiber layer, the junction of the solid fiber layer and the second hollow fiber layer, the dryer output Hot air: The temperature of hot air is continuously raised from 125 degrees to 150 degrees, and the heating time is 5 minutes.

2. The method for preparing a sandwich flake according to claim 1, characterized in that: The needles of the two dryers are extending After the blank is put in, the needle tubes are arranged continuously in front and back to cover the drying area of ​​the blank.

3. The method for preparing a sandwich flake according to claim 2, characterized in that: The space between two adjacent rows of needle tubes The distance is 8cm.

4. The method for preparing a sandwich flake according to claim 3, characterized in that: The outer peripheral wall of the roller is provided with With embossed patterns.

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