TW201132819A - Method to increase whiteness recycling of PET fibers and core-sheath type PET fibers manufactured by the same - Google Patents

Abstract

The method to increase whiteness recycling of PET (Polyethylene Terephthalate) fibers is to proceed spinning of the compositions formed of recycled PET (Polyethylene Terephthalate) with degree of whiteness hue between 55-80 and PET (Polyethylene Terephthalate) with degree of whiteness hue between 85-95 by a composite fiber spinning machine, thereby producing a core-sheath type PET (Polyethylene Terephthalate) fiber, wherein the core layer is formed by the recycled PET (Polyethylene Terephthalate), the sheath layer is formed of the compositions, and the cross section of the fiber is a concentric circle, the relation between the radius R1 of the inner circle and the radius R2 of the outer circle in the concentric circle is as the following formula (I) : 1.11≤R2/R1≤4.48 (I).

Description

201132819 VI. Description of the Invention: [Technical Field] The present invention relates to a method for improving the whiteness of polyethylene terephthalate (PET) fiber, in particular, a method for improving recycling A method of whiteness of polyethylene terephthalate fibers. The invention further relates to a core-sheath type polyethylene terephthalate fiber produced by the method. [Prior Art] With the rise of environmental awareness, the industry has gradually paid attention to the recycling and reuse of materials, especially plastics. Polyethylene terephthalate is one of the most common plastic materials for packaging. Made into a variety of bottles and used to hold a variety of beverages, mineral water or milk, even motor oil, etc. Therefore, in recent years, environmental protection units have actively promoted the recycling and reuse of polyethylene terephthalate waste 'for example, Re-formed into fibers. The treatment method for recycling such wastes is to first classify the recovered poly(p-phenylene terephthalate) waste, and then carry out the steps of crushing and washing. However, in the final recycled materials, there is inevitably still unwanted. The residue is present, so if the fiber is to be produced from recycled polyethylene terephthalate, most of the following problems occur: (1) The whiteness of the obtained fiber is not good because of the recovered polyphenylene terephthalate. Ethylene formate usually has a yellowish color; and (2) the dyed main color ratio of the known fiber is not good, because there are other impurities in the polyethylene terephthalate recovery material, and in different batches of recycled materials The composition and content of impurities are not the same, that is, there are differences that are difficult to control. In response to the above problems, the current corresponding practice in the industry is mainly to classify the polyethylene terephthalate recycled material by the artificial method 201132819, the material (the whiteness is within the acceptable range) and make it a large number of = After the mouth, 'according to the quality of the finished fiber products, the quality of the finished fiber can be selected by the downstream customers. However, this method is mainly carried out by manual screening, so it takes a lot of manpower and cost, and at the same time, it also consumes the preparation and quality control cost of the finished fiber product. The same batch of recycled materials are dyed before, during and after the same batch. The color ratio is also very different. Part of the whiteness and in addition, due to the need to eliminate many of the poorly recovered backstock and finished fiber products in the manual screening process, the yield is low, which further increases the cost of production. In order to solve the above problems, Weishang began to try to add pure polyethylene terephthalate in the recovery value of polyethylene terephthalate with lower whiteness hue value than W. Condensation polymerization of phthalic acid and monoethylene glycol 4, and the use of unused polyethylene terephthalate is not widespread, this method has limited effect on the improvement of fiber whiteness, and the main color dyeing rate is poor. The problem of uneven quality of fiber products still cannot be effectively improved. Overall, Lu's improvement in this way is still limited. Therefore, there is still a need to develop a method for environmentally friendly, low preparation and quality control, and capable of improving the whiteness of recycled polyethylene terephthalate fibers and increasing the production rate of recycled materials. SUMMARY OF THE INVENTION Therefore, the first object of the present invention is to provide a whiteness of polyethylene terephthalate fiber which can meet the environmental protection and various costs, and which can have the properties of New Zealand fiber. method. 201132819 ? ^ The method for improving the whiteness of recycled polyethylene terephthalate fiber of the present invention is a recovered polytrimethylene phthalate whose whiteness hue value (ie, L value) is between 55 and 80. T-Mann-酉曰' and a composition comprising a white color hue value of between 85 and 95, which is a composition of poly(p-dibenzoic acid), which is woven by a composite fiber spinning machine. In turn, a core-sheath type polyethylene terephthalate--S-day fiber is produced, and in the pot, the horse r#思0丄Ύ4 core layer is composed of the recovered polyethylene terephthalate. The layer is a cross-section of n fibers composed of the composition

The surface is H concentric® 'and the radius of the inner circle of the concentric circle & the relationship with the radius R2 of the outer circle is as shown in the following formula (1): 1.1 l^R2/R,^ 4.48 (I) 0 The second object of the present invention That is, it provides a polyethylene terephthalate fiber which can balance environmental protection and various costs, and has improved whiteness. The present invention-type (IV)-type poly-p-benzoquinone is produced by a method of polyethylene terephthalate for fiber whiteness as described above. The effect of the present invention is that the method of the present invention utilizes a composition comprising polyethylene terephthalate having a whiteness hue value between 85 and 95, and the existing recovered poly(p-xylylene phthalate) The ratio of the radius of the core layer to the thickness of the layer of the layer of the second vinegar is controlled to be within the range of the meaning of the invention, and the environmental protection and various costs can be considered. The whiteness of the recovered polyethylene terephthalate fiber is effectively increased, and the production rate of the recycled material is increased. [Embodiment] In view of the fact that the whiteness of the currently recovered polyethylene terephthalate fiber is not effectively improved, the inventors have developed a polyparaphenylene which can effectively improve the recovery after extensive research. The method for whiteness of ethylene formate fibers is to coat the recovered polyethylene terephthalate fibers with pure polyethylene terephthalate fibers to form a core-sheath fiber and simultaneously control the core. The ratio of the inner and outer radii of the bismuth layer fiber is within the scope defined by the present invention (rather than simply controlling the thickness of the sheath). The method disclosed in the present invention can be effective in the context of both cost and finished fiber quality. The effect of improving the whiteness of the recovered polyethylene terephthalate fiber. According to the invention, a method for improving the whiteness of the recovered polyethylene terephthalate fiber, which is a whiteness hue The recovered polyethylene terephthalate having a value between 55 and 8 Å, and a composition comprising polyethylene terephthalate having a whiteness hue value between 85 and 95. With The composite fiber spinning machine is known to be spun, thereby producing a core-type polyethylene terephthalate fiber. As shown in Fig. 1, the core-type polyethylene terephthalate fiber comprises a layer. 1 "layer 2" is composed of the recovered polyethylene terephthalate-s day. The layer 2 is composed of the group of money, and the cross section of the fiber is presented as a concentric circle. Wherein, the periphery of the core layer 1 is the circumference of the inner circle of the concentric circle. The contact a Λ , θ , the periphery of the tendon sheath 2 is the circumference of the circle outside the concentric circle. The radius R has the following The relationship between the radius Ri of the inner circle and the outer circle shown in the formula (I) is: 111 - R2/Ri ^ 4.48 (I). In the case of .11, the amount of pure PET supplied as a sheath is too small. The thickness of the pET fiber is not sufficient to cover the color of the recycled PET f-dimensional of the core layer so that the color of the recovered PET fiber of the core layer (mainly yellowish) is transmitted through a layer of pure PET fiber, resulting in a dimension The overall appearance of the hue is not recorded low, u value is high); and when R2 / Rl > 4.48, the whiteness hue value of the obtained PET fiber Although the Lb value and the dyeing rate can be improved, the amount of recycled PET used at this time is too low, which will make the so-called "environmental appeal" meaningless. It is better to emphasize the so-called "environmental appeal". R2/m7i; preferably R2/R1 S 2.00. The above whiteness hue value represents the lightness of the fiber, and the higher the value, the better the whiteness of the fiber is displayed; the La value represents the red color of the fiber. The green color degree 'positive value indicates that the fiber color is reddish, the negative value indicates that the fiber color is greenish; the Lb value represents the yellow and blue lacking color of the fiber. The positive value indicates that the fiber color is yellowish, and the negative value indicates The color of the fiber is blue. Among them, the existing recycled PET regrind and the pure pET @ L value are between -3.0 and 0', which are in line with the industry standards, so this section is not described in this case. The inventors have found through various studies that if PET fibers are coated with pure PET fibers as a sheath, it is not sufficient to control the thickness of the layer to completely achieve the object of improving the hue of the fibers of the present invention. As the radius of the S layer increases with the same sheath thickness, the improvement effect on the appearance of the fiber will decrease. As described above, the recovered polyethylene terephthalate fiber obtained by the method of the present invention is dyed by the dye main dye 7 201132819. The outer layer of the recovered poly(p-bismuth dicarboxylate) fiber is coated with a enamel layer composed of pure PET, so that the dyeing effect similar to that of the pure PET fiber can be obtained, and the similar (four) color ratio is obtained. This effectively avoids the conventional technique of imparting unevenness due to the inclusion of back in the outer layer of the fiber: PET (which usually contains impurities or other components that affect the dyeing effect). Those skilled in the art of the present invention, through the teachings of the techniques disclosed in the present specification, can readily appreciate that the core (four) fibers can be conditioned in a variety of ways during fiber preparation, the radius of the core layer and the layer of the core layer. The thickness is not particularly limited in the present invention for the method of controlling the radius of the core layer and the thickness of the sheath. Any conventional or unknown technique can be used for the present invention as long as it can produce a fiber having a specific m fiber outer circle to inner radius ratio in the present invention. Here, for example, but not limited to, for example, when spinning with a core-type fiber spinning machine, when the polyester ester particles are passed through an extruder and melted at a high temperature, a metering pump (metedngpump) is simultaneously used. By controlling the feed amount of the core layer and the sheath (thr0Ughput), any desired core radius and sheath thickness can be obtained. Although the method of the present invention can effectively improve the appearance hue of the recovered polyethylene terephthalate fiber, but if the hue of the recycled material is too poor, that is, the whiteness hue value is lower than 55, it is improved by the method of the present invention, and finally There may still be no satisfactory final appearance hue. To ensure acceptable quality of the improved fiber appearance hue, preferably, the recovered polyethylene terephthalate has a whiteness hue value between 6 〇 and 201132819. Further, preferably, the recovered polyparaphenylene ketoethyl ester has an Lb value of between 1 Torr and 4 Å. Note that the whiteness hue value of the generally recovered PET bottle waste is between 55 and 80, and the Lb value is between 10 and 4. The whiteness hue value of the commercially available 'and polyethylene terephthalate is between 85 and 95. The white enamel of the recycled polyethylene terephthalate fiber product is expected in the industry. The hue value is not less than 85, and you can see the higher products that the industry can produce.

The whiteness hue value of the recycled polyethylene terephthalate fiber product is usually "between 85 i 89; the Lb value is not higher than 4, and the main dyeing rate is expected to be more than 91%. The white recovered polyethylene terephthalate fiber obtained by the method of the present invention is obtained by the inventor through a plurality of experimental studies to obtain a ratio between 'f R2 and Rl' which is within the scope of the present invention. The characteristics of the hue value, Lb value, and main color rate of dyeing can not only meet the current standards for high quality recycled PET fiber, but also achieve high standards. Material, Tian W is the basic material of the invention. The special method of the invention is limited. Therefore, the method of the invention can greatly reduce the labor of selecting the recycled materials by manual labor, and it is not necessary to carry out the manual sorting work after the fiber is made. In addition, since there is no need to specially filter the recycled materials. The quality, that is: is the nature of the difference 'for example, the whiteness hue value that can not be utilized by the prior art is between 75 and 55. (4) Recycled material 1 can be applied to the method of the present invention, so the method of the present invention is acceptable, Increase the utilization rate of recycled materials Thereby, the method of the invention can be made larger than the conventional technology, and the labor cost and the raw material cost are greatly reduced. 201132819 In addition, the recycled poly(p-dibenzoate) fiber obtained by the method of the invention has an outer layer. The encapsulation layer is composed of pure PET, so that the whole fiber is close to pure PET fiber in nature. Therefore, those skilled in the art of the present invention can easily think through the teachings of the present specification. The recycled polyethylene terephthalate fiber obtained by the method of the present invention is added to the composition for the silk layer by adding a conventional additive, for example, 'addition of titanium dioxide. The material of (Ti〇2) can achieve the effect of matting. The core-sheath type polyethylene terephthalate fiber of the present invention is recovered by the polyethylene terephthalate fiber which is recovered as mentioned above. Preferably, the core-sheath type polyethylene terephthalate fiber is an undrawn yarn (UDY) and a partially oriented yarn (referred to as ρογ). ), a false 捻Draw textured yarn (DTY) or fully oriented yarn (FOY) 〇 Examples The present invention will be further illustrated by the following examples, but it should be understood that 'these embodiments are only The description is for illustrative purposes and should not be construed as limiting the implementation of the invention. <Chemical Source> 1. Recovered polyethylene terephthalate pellet: purchased from Far East New Century; Model CFF -290R. 10 201132819,. Poly(p-phenylene) formic acid Ethylene fiber: purchased from the Far East New Century; model CSS-910 〇<instrument source> I spinning machine: purchased from Toray Corporation of Japan; The model number is τ. Kidney 5〇3. 2_ Spectrophotometer: Purchased from scratch. <Measurement method of dye main color rate>

The measurement of the color rate is firstly made of a plurality of general pure PET fibers (standard yarns): the fabrics of the articles to be tested are respectively woven from a fabric made of a plurality of fibers to be tested. The test sample with the half of the fabric to be tested is dyed by a conventional dyeing method, and then the degree of dyeing of the fabric on the dyed test sample is discriminated by artificial vision. When the color of the fabric to be tested is darker or lighter than the standard yarn, it is classified as D grade or L grade; and if it is different from the yarn color, it is classified as Μ grade. Finally, calculate the ratio of the fabrics that are classified into 4 grades to the total samples, and then calculate the dominant color ratio of the samples to be tested. For example, when 100 samples were prepared, 95 of which were broken into sputum grades, the main staining rate of the analyte was 9 outside. [Preparation of core-sheath type polyethylene terephthalate fibers] <Examples 1 to 8 and Comparative Examples 1 and 2> Examples 1 to 8 and Comparative Examples! And 2 are according to the radius ratio parameter (R2/Ri) of the outer and inner circles of the fiber shown in the following table, and the predetermined amount of polyethylene terephthalate and pure polyethylene terephthalate can be They were respectively placed in two extruders of an extruder, and were spun to obtain a sheath-type polyethylene terephthalate fiber. 201132819 The inventor further measures the strength of the core-sheath type polyethylene terephthalate fibers of Examples i to 8, and the comparative work and 2 according to the CNS L4060 test method and the above-mentioned method for measuring the main color ratio of dyeing. , elongation and dyeing primary color rate. In addition, the L value and the u value of the finished fiber products are obtained by using a spectrophotometer and measured according to the operation manual, and the results obtained by the measurement are shown in Table 1 below. <Example 9> Example 9 is a predetermined amount of recovered polyethylene terephthalate, with a ratio of the outer diameter of the outer circumference of the fiber shown in Table 1 below, and a 2.4 wt. /6 - titanium oxide and 97 6 wt% of pure polyethylene terephthalate fiber composition, respectively, were placed in a two-spinning machine of a spinning machine for spinning 'and then made _ core 35 poly Ethylene terephthalate fiber. The inventors also conducted the same properties test as in Example 1 for the core-sheath type polyethylene terephthalate fiber of Example 9, and the results obtained are also shown in Table 1 below. ° As can be seen from Table 1, the addition of titanium dioxide to the composition of the sheath does not affect the efficacy of the present invention and can be applied to the present invention. <Comparative Example 3 ><Comparative Example 4 > Comparative Example 3 is a spinning-polyethylene terephthalate fiber in which a pure polyethylene terephthalate is placed in a thread visitor . Similarly, the inventors also conducted the same properties test as in Example 1 on the polyethylene terephthalate fiber of Comparative Example 3, and the results obtained are also described below.歹1 lL J-cA Λ \ Spinning Comparative Example 4 was to put the recovered polyethylene terephthalate into a 12 201132819 wire machine and spun into a polyethylene terephthalate fiber. Similarly, the inventors also tested the same properties as in Example 1 for the polyethylene terephthalate fibers of Comparative Example 4, and the results obtained are also shown in Table i below. <Comparative Example 5> Comparative Example 5 was obtained by uniformly mixing pure polyethylene terephthalate and recovered polyethylene terephthalate in a spinning machine and melt-blending it into a spinning machine. - Poly(p-phenylene dicarboxylate) I fibers. Similarly, the inventor also

The results of the same (4) test as in Example 1 for the poly(p-dibenzoic acid) of Comparative Example 5 were also described in the following table.

13 201132819 Table 1

From the case of Example 3 to / because it is not a core-sheath type fiber, there is no ratio of defects.

It can be seen from the above Table 1 that the polyethylene terephthalate fibers obtained in Examples 1 to 9 can meet not only the whiteness hue and b value required by the industry, but also the main color ratio of dyeing. Excellent performance, and the physical properties such as strength and elongation of these dimensions are also comparable to pure polyethylene terephthalate. 14 201132819 ” vT' described above 'the method of the invention utilizes a core-type fiber structure and uses a composition comprising a pure polyethylene terephthalate as a raw material for the sheath' to improve the existing recovered poly-p-phenylene The whiteness of the formic acid ethanediacetate fiber is mainly controlled by controlling the ratio of the radius of the core layer to the thickness of the sheath layer, that is, the ratio of the radius of the inner circle of the fiber to the radius of the outer circle, thereby further balancing environmental protection and In the case of various costs, the whiteness of the recovered polyethylene terephthalate fiber is effectively improved, so the object of the present invention can be achieved. However, the above is merely a preferred embodiment of the present invention. The simple equivalent changes and modifications made by the invention in the scope of the invention and the description of the invention are still within the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a cross section of a core-type polyethylene terephthalate fiber of the present invention.

Claims (1)

201132819 VII. Patent application scope: 1 · A method for improving the whiteness of recycled polyethylene terephthalate fiber, which is a recycled poly-p-phenylene with a whiteness hue value between 55 and 80 Ethylene formate' and a composition comprising polyethylene terephthalate having a whiteness hue value between 85 and 95, which is spun by a composite fiber spinning machine to obtain a core sheath Type polyethylene terephthalate fiber 'where the core layer is composed of the recovered polyethylene terephthalate, the sheath layer is composed of the composition, and the fiber is transversely broken The facet presents a concentric circle, and the relationship between the radius Ri of the inner circle of the concentric circle and the radius R2 of the outer circle is as shown in the following formula (1): 1.11^ R2/Ri ^ 4.48 (1). The method for improving the whiteness of the recovered polyethylene terephthalate fiber according to the first aspect of the patent application, wherein the white color hue value of the recovered polyethylene terephthalate is between 6〇 to 8〇. A method for improving the whiteness of recovered polyethylene terephthalate fiber as described in the scope of the patent application, wherein R2/Ri$ 3.71 in the formula (1). 2. 3. 4. According to the method of the third aspect of the patent, the method for collecting the whiteness of the polyethylene terephthalate, which is in the range of the patent, wherein, in the formula (1), r2/r^ 2.00 〇5 The method for improving the recovered whiteness of the polyethylene terephthalate of the polyethylene terephthalate according to the item i of the patent scope, wherein the Lb value of the polyethylene terephthalate at this time is between 1 〇 to between 4. 6_ - a core-type polyethylene terephthalate fiber, which is a method for improving the whiteness of recycled polyethylene terephthalate fibers as described in claim 1 of claim 16 201132819 Made by. 7. The core-sheath type polyethylene terephthalate fiber according to claim 6, wherein the core-sheath type polyethylene terephthalate fiber is an unstretched yarn, a half-stretched yarn, a false twisted textured yarn or a fully drawn yarn. 17