A method for improving the strength of raw silk

Abstract

This invention discloses a method for increasing the strength of raw silk. By regulating the temperature during the cocooning process, the properties of the cocoons and silk fibers are improved, and the differences in relative strength between different cocoon and silk zones are reduced. The resulting 20 / 22D raw silk has a cohesion force of 98 times and a strength of 96 cN. Based on the physiological characteristics of silkworms during the spinning process, this method improves the strength of raw silk by controlling temperature conditions. The method is easy to operate, low-cost, and readily applicable.

Description

Technical Field

[0001] The invention relates to a method for improving the strength of raw silk, and in particular to a method for reducing the fineness difference of cocoon silk, improving the cohesion of raw silk and improving the strength of raw silk by adjusting the ambient temperature conditions during the cocooning process. Background Art

[0002] silkworm( Bombyx mori ) is an important economic insect that has been domesticated and raised for over 5,700 years. The silkworm, a holometabolous Lepidoptera insect, undergoes complete metamorphosis, progressing through the stages of egg, larva, pupa, and adult. Its primary source of nutrients is mulberry leaves, which it feeds on during its larval stage. Silkworms are typically divided into five instars: 1st, 2nd, 3rd, 4th, and 5th. In the latter half of the 5th instar, silkworms spin cocoons, which are then reeled to produce raw silk, providing an important raw material for textile production.

[0003] Silkworms' cocooning protects the pupae from predators during their metamorphosis and also helps eliminate excess amino acids from the body, preventing amino acid poisoning. With the large-scale development of the sericulture industry, to reduce the labor input required to capture mature silkworms, a technique has become common practice: feeding silkworms molting hormones after reaching maturity (1% maturity) and then placing them on cocoons together 24 hours later. Currently, the commonly used cocooning temperature is 23-25°C. After feeding silkworms molting hormones, silkworms spin silk more quickly and move their silk threads more frequently during the initial cocooning, resulting in smaller cocoon fineness. Later in the cocooning process, the amount of silk gland material decreases, resulting in smaller cocoon fineness. This leads to significant variations in cocoon fineness, directly affecting the relative strength of the cocoons and the cohesive force of the raw silk, ultimately affecting the strength of the raw silk. This has become a key issue hindering the high-quality development of the cocoon and silk industry. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for improving the strength of raw silk to promote the high-quality development of the cocoon and silk industry.

[0005] In order to achieve the above-mentioned purpose of the invention, the technical solution adopted by the present invention is: a method for improving the strength of raw silk, comprising the following steps: after the silkworms are cocooned, adjusting the temperature of the silkworms at different stages of cocooning, until the silkworms are finished cocooning, thereby improving the strength of the raw silk.

[0006] The invention adjusts the temperature of silkworms at different stages of cocooning to control the fineness difference of different parts of cocoons and silk, thereby producing raw silk with good cohesion and improving the strength of the raw silk.

[0007] The present invention controls the fineness difference of different parts of the cocoon by adjusting the ambient temperature conditions at different spinning stages based on the physiological characteristics of the silkworm. Preferably, the different stages of cocooning are divided into five stages: 0 to 12 hours of cocooning, 12 to 24 hours of cocooning, 24 to 36 hours of cocooning, 36 to 48 hours of cocooning, and 48 hours of cocooning until the end of cocooning. The five stages are defined based on the overall cocooning process.

[0008] In the present invention, the temperature range of silkworms in different stages of cocooning is 20°C to 23°C. Preferably, the temperature of silkworms in different stages of cocooning is adjusted by a low temperature at the front and back and a high temperature in the middle. Specifically, the ambient temperature for 0 to 12 hours of cocooning is 20°C, the ambient temperature for 12 to 24 hours of cocooning is 21°C, the ambient temperature for 24 to 36 hours of cocooning is 23°C, the ambient temperature for 36 to 48 hours of cocooning is 22°C, and the ambient temperature from 48 hours of cocooning to the end of cocooning is 21°C.

[0009] Due to the application of the above technical solution, the present invention has the following advantages:

[0010] 1. By controlling the temperature conditions during the cocooning process, the relative strength of the cocoons and silk threads is controlled, ultimately increasing the cohesion and strength of the raw silk. The difference in relative strength of different parts of the cocoons and silk threads produced by the present invention is less than 2%. The cohesion of the raw silk produced is greater than 98 times, and the strength of the 20 / 22D raw silk produced is greater than 96 cN.

[0011] 2. The method disclosed in the present invention uses fewer control parameters, has the characteristics of low cost, easy operation, and convenient promotion and application. DETAILED DESCRIPTION

[0012] The present invention will be further described below in conjunction with the embodiments:

[0013] The silkworm varieties of the present invention, Suxiu x Chunfeng, are currently available. One silkworm bed (25,000 silkworms) was raised in each of the experimental and control areas, using conventional methods during the spring silkworm season. The mulberry tree variety used was Yu 711. Cardboard grid cocoons (12 x 13 = 156 grids) were used for cocooning. The ambient temperature during cocooning was controlled using an intelligent temperature control system from Nanjing Shijue Electronic Technology Co., Ltd., with an accuracy of 0.1°C. Strength was measured using a YG021D electronic single yarn strength tester, using a German Sartorius BSA224S balance. Cohesion was measured using a Y731 cohesion machine, and silk length was measured using a vertical hand-cranked reeling machine. After drying, the cocoons were commissioned to Jiangsu Huajia Silk Co., Ltd. to produce 20 / 22D raw silk using an automatic reeling machine (Feiyu 2000).

[0014] Based on the physiological characteristics of silkworms, the present invention controls the fineness differences of different parts of the cocoon by adjusting the ambient temperature conditions during different spinning stages. The cocooning stages are divided into five phases: 0-12 hours (excluding 0), 12-24 hours (excluding 12), 24-36 hours (excluding 24), 36-48 hours (excluding 36), and 48 hours to the end of cocooning (excluding 48). These five phases are based on the overall cocooning process.

[0015] Comparative Example 1 Parameter detection under existing commonly used cocooning temperature conditions

[0016] Conventionally reared silkworms were cocooned at a commonly used cocooning temperature of 24°C. Seven days after cocooning, cocoons were harvested and tested for silk quality. 1,000 cocoons (half male and half female) were sampled from each group, with three replicates. Table 1 shows the average of the three groups. The results showed that raw silk produced at a 24°C ambient temperature had poor cohesion and low strength.

[0017]

[0018] Comparative Example 2 Parameter detection under the condition of 23℃ clustering temperature

[0019] Cocoons were collected from conventionally reared silkworms at a cocooning temperature of 23°C throughout the entire cocooning process. Seven days after cocooning, 1,000 cocoons (half male and half female) were sampled from each group. Three replicates were set up, and the average of the three groups was used. The results showed that, at a 23°C ambient temperature, the strength of 20 / 22D raw silk produced was 83.5 cN.

[0020] Example 1 Parameter detection under the temperature conditions of the clustering of the present invention

[0021] Differentiated environmental temperature controls were applied to different spinning periods. The cocooning phases were divided into five stages: 0-12 hours, 12-24 hours, 24-36 hours, 36-48 hours, and 48 hours to the end of cocooning. Seven days after cocooning, cocoons were harvested and their silk quality tested. 1,000 cocoons (half male and half female) were sampled from each group, with three replicates. Table 2 shows the average of the three groups. The silk length was approximately 1,700 meters. Conventional temperature control was used, for example, starting with a temperature increase to 21°C after the 12th hour of cocooning and continuing in this manner.

[0022] The results show that the present invention can significantly improve the performance of raw silk, the relative strength index is more stable, ranging from 1.61 to 1.65 cN / D, the cohesion force times are increased to 98 times, and the strength of 20 / 22D raw silk reaches 96 cN.

[0023]

[0024] Example 2

[0025] Differentiated ambient temperatures were applied to the silk-spinning process at different times. The cocooning phase was divided into five stages: 20°C from 0 to 12 hours, 21°C from 12 to 24 hours, 22°C from 24 to 36 hours, 23°C from 36 to 48 hours, and 23°C from 48 hours to the end of the cocooning process. Results showed that this gradual increase in ambient temperature resulted in a 20 / 22D raw silk with a strength of 89 cN.

[0026] Silk: the single filament spun from each cocoon, usually 1000 to 1700 meters long; Raw silk: a fiber of certain specifications spun from multiple cocoons; Denier: expressed as the weight of fiber per unit length, measured in denier (D), which refers to the mass in grams of 9000 meters of fineness; Cohesion: the number of times raw silk is rubbed to separate into single filaments; Strength: the force required to stretch a silk or raw silk to break, measured in centinewon (cN); Relative strength: the strength per unit fineness, measured in cN / D.

[0027] Silkworm silk production is a complex physiological process influenced by multiple factors, with a short production cycle. Existing research has yet to investigate how controlling environmental conditions during different silk production stages can influence silk properties. This invention, based on the physiological characteristics of silkworms, precisely controls the relative strength of different silk components by regulating temperature, thereby increasing cohesion and raw silk strength. This method is highly practical and easy to operate.

Claims

1. A method for improving the strength of raw silk, comprising the following steps: after silkworms are cocooned, adjusting the temperature at different stages of the cocooning process until the silkworms have finished cocooning, thereby improving the strength of the raw silk; the different stages of cocooning are divided into five stages, namely, 0-12 hours after cocooning, 12-24 hours after cocooning, 24-36 hours after cocooning, 36-48 hours after cocooning, and 48 hours after cocooning until the end of cocooning; the temperature at 0-12 hours after cocooning is 20°C, the temperature at 12-24 hours after cocooning is 21°C, the temperature at 24-36 hours after cocooning is 23°C, the temperature at 36-48 hours after cocooning is 22°C, and the temperature at 48 hours after cocooning until the end of cocooning is 21°C; the temperature is ambient temperature; and the raw silk specification is 20 / 22D.

2. The raw silk prepared by the method for improving raw silk strength according to claim 1, characterized in that: The cohesive force of raw silk is greater than 95 times, and the strength of 20 / 22D raw silk is greater than 95cN.

3. Use of the raw silk according to claim 2 in the preparation of high-strength silk products.

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