Material Science Popularization: Hand Feeling Standard And Evaluation Method Of Knitted Fabrics

The hand feeling standards of knitted fabrics mainly include the following comprehensive aspects:

1. Softness

• Standard: High quality knitted fabrics are soft and comfortable to the hand, which can give people a warm and intimate feeling, and are not easy to wrinkle or deform.

Assessment method: feel the softness of the fabric by touching it with hands. Usually, the fabric can be gently squeezed in the hand. If it can easily deform without obvious resistance, it will be soft. You can also lay the fabric on the table and press it gently with your hand to observe its springback. The fabric with rapid springback and smooth recovery will have better softness.

2. Smoothness

• Standard: The surface of the fabric should be smooth and smooth, without roughness when contacting the skin, and the friction coefficient is small, giving a smooth tactile experience, which is closely related to the smoothness, softness and gloss of the fabric.

Assessment method: gently touch the surface of the fabric with your hand to feel its smoothness. The fabric can be repeatedly rubbed in the hand. If there is no obvious resistance and the hand feel is smooth, the smoothness is better. In addition, the glossiness of the fabric can also be observed. The fabric with higher glossiness usually has better smoothness.

3. Flexibility and resilience

　　• Standard: Knitted fabrics should have good elasticity and resilience, be able to be stretched or compressed under the action of external force, and quickly return to the original state after removing the external force, not easy to deform or relax, which makes the fabric more durable and more fit the body when wearing.

Assessment method: stretch the fabric by hand, observe its elongation, and then release the hand to see whether the fabric can be quickly restored to its original state. The fabric can also be curled or folded, and then unfolded to check whether there is obvious crease or deformation on the surface of the fabric. If there is no obvious trace and it can be quickly restored, then the elasticity and resilience are good.

4. Thickness

• Standard: The thickness of knitted fabrics varies according to different use needs and seasons. Generally speaking, thicker fabrics have good warmth retention and are suitable for autumn and winter; Thin fabric is light and breathable, suitable for spring and summer.

Assessment method: feel the thickness of the fabric through visual inspection and hand touch. You can compare the fabric with other fabrics of known thickness, or press the fabric with your fingers to feel its density and thickness. In addition, some instruments and equipment, such as thickness gauge, can also be used to accurately measure the thickness of the fabric.

5. Weight

• Standard: The weight of knitted fabrics is usually expressed in grams or grams. Heavier fabrics are generally thicker and have good warmth retention; Lighter fabrics are lighter and more comfortable to wear.

Assessment method: You can pick up the fabric with your hands and feel its weight, or use weighing tools to accurately measure the weight of the fabric. In practical applications, you can choose the right weight of fabrics according to different product needs and use scenarios.

6. Texture

• Standard: The surface texture of the fabric should be clear and even, without obvious flaws or defects. Different textures will bring different visual and tactile feelings, affecting the overall style and comfort of the fabric.

Evaluation method: evaluate the texture of the fabric through observation and touch. You can carefully check the fabric surface structure to see if there are broken threads, skipped stitches, color differences and other defects. At the same time, touch the fabric with your hand to feel the fineness and uniformity of its texture. The fabric with clear, uniform texture and comfortable hand feel has better quality.

7. Moisture absorption and air permeability

• Standard: Knitted fabrics should have good moisture absorption and permeability, be able to absorb and distribute human sweat, and keep skin dry and cool.

Evaluation method: The hygroscopicity of the fabric can be evaluated through a simple water absorption experiment. Immerse a corner of the fabric in water to observe its water absorption speed and diffusion range. The permeability can be evaluated by covering the fabric on the nose and mouth and feeling its permeability.

8. Gloss

• Standard: The fabric should have natural luster, giving people a beautiful and high-grade feeling.

Evaluation method: Observe the luster of the fabric under natural light or light. The fabric with uniform luster and natural quality is better.

9. Hairling and pilling

• Standard: The fabric should not be easy to fuzz and pilling, and the surface should be smooth and tidy.

Evaluation method: The fuzzing and pilling property of the fabric can be evaluated by friction test. Rub the fabric on the rough surface repeatedly, and observe whether there are hair balls on the surface.

10. Dimensional stability

• Standard: The fabric should have good dimensional stability, and it is not easy to deform and shrink during washing and use.

Evaluation method: The dimensional stability of the fabric can be evaluated through washing experiments. After washing the fabric, measure its size change. The fabric with small size change has better dimensional stability.

These aspects together constitute a comprehensive evaluation standard for the hand feel of knitted fabrics. By comprehensively considering these factors, the comfort and durability of fabrics can be ensured.

Evaluation method for hand feeling of knitted fabrics:

The evaluation methods of knitted fabric handle mainly include the following:

Subjective assessment method: one pinch, two touch, three grasp, four look

One pinch: Hold the edge of the cloth with three fingers, the front side of the fabric facing up, gently pinch the fabric, and feel its thickness, density and elasticity. High quality fabric has a full and elastic feel when it is pinched, and can quickly restore its flatness after release.

Second touch: gently touch the surface of the fabric with your fingers to feel its smoothness, softness and delicacy. High quality knitted fabric feels smooth, soft, without roughness, and feels fine.

Three Grasping: Grasp the fabric with your hands to feel its weight, thickness and drapability. Fabrics with moderate weight and good drapability are usually of good quality, which are more suitable for the body and more beautiful in appearance.

Fourth, observe the appearance characteristics of the fabric such as color, texture and gloss. The color shall be bright and uniform without color difference; The texture is clear and uniform, without obvious defects; The luster is natural and soft, without dazzling reflection.

Objective evaluation method:

Instrument test: use professional fabric tactile tester, such as FTT ® Fabric touch tester, etc., tests the physical indicators of knitted fabrics, such as bending length, drapability, friction coefficient, etc., and then establishes a connection with the evaluation grade of professional feel personnel according to the test results, so as to accurately evaluate the fabric feel. FZ/T 01166-2022 Textiles and Fabrics Tactile Detection and Evaluation Method: Multi index Integration Method stipulates the method of testing and evaluating the hand and touch of textiles through multi index instruments, providing a universal objective evaluation standard for the industry.

Evaluation of relative hand feeling value:

Knitted fabrics without post finishing or new materials are selected as reference samples, and the fabrics to be tested are compared with the reference samples. The relative hand feeling value of the fabrics to be tested is determined through the subjective evaluation of professionals and instrument testing, so as to evaluate the hand feeling quality.

How to improve the hand feel of knitted fabrics and methods:

Here are some ways to improve the feel of knitted fabrics:

Physical and mechanical finishing:

Preshrinking: reduce the shrinkage of the fabric after soaking by physical means to reduce the shrinkage rate and make the fabric feel softer.

Stretching: The fabric width is gradually widened to the specified size for drying, making use of the plasticity of the fiber in wet conditions, so that the fabric shape is stable and the feel is improved.

Sanding and buffing: use sanding roller (or belt) to grind a layer of short and dense fuzz on the surface of the fabric, which can make the warp and weft yarns produce fuzz at the same time, and the fuzz is short and dense, so that the fabric feels soft.

Hairling: The fibers on the surface of the fabric are picked up with dense needles or pricks to form a layer of fuzz, which is mainly used for woolen fabrics, acrylic fabrics and cotton fabrics. The fuzz layer can improve the warmth retention of the fabric, improve the appearance and make the hand feel soft.

Shearing: use a shearing machine to cut off unwanted fuzz on the surface of the fabric, so that the fabric texture is clear and the surface is smooth, or make the fuzz or pile surface of the fuzzed and pile fabric neat, so as to improve the hand feel.

Chemical softener finishing:

Softener: Softener can reduce the dynamic and static friction coefficient of the fabric surface, so that the fabric feels soft and smooth. There are many kinds of chemical softeners, and different types of softeners have different hand feel styles. You can select appropriate softeners according to specific needs.

Acid cellulase treatment: for mercerized cotton knits, acid cellulase treatment can be carried out first to remove the surface fuzz, improve the grain clarity and smoothness, and then improve the fabric feel. The optimized enzyme treatment process is: the amount of acid cellulase UTA-8 is 1.0% - 2.0%, and the pH value is about 5.0.

Optimize yarn and weaving process:

Select appropriate fibers and yarns: the fineness and dispersion of fibers will affect the hand feel of fabrics. Generally speaking, when the twist of yarns is certain, the finer the fineness of fibers, the softer the fabrics woven from the produced yarns will be. On the contrary, the stiffer the fabrics will be. Therefore, the fiber with moderate fineness can be selected, and the optimal fiber ratio can be determined by orthogonal test and other methods.

Control of yarn twist: under the premise of ensuring yarn strength, properly reduce the twist of yarn to improve the handle hardness of fabric.

Other methods:

Liquid ammonia finishing: the cotton fabric is treated with liquid ammonia, which can eliminate the internal stress in the fiber, improve its gloss and serviceability, reduce the shrinkage of the fabric, increase the resilience, breaking strength and moisture absorption, and make it soft, elastic, crease resistant, and dimensional stable.

Press finishing: under wet and hot conditions, the wool fabric is leveled by mechanical pressure to improve luster and feel. There are two ways of pressing: rotary pressing and cardboard electrothermal pressing, but attention should be paid to the problems of huge equipment and low production efficiency.

The influence of yarn twist on the handle of knitted fabrics:

The influence of yarn twist on the feel of knitted fabrics is mainly reflected in the following aspects,

The handle of knitted fabrics can be improved by reasonably controlling the twist:

Relationship between twist and feel:

Moderate twist: Generally speaking, the twist of knitting yarn is lower than that of woven yarn. If the twist is too large, the flexibility of the yarn will be poor. It is not easy to be bent and twisted during weaving, and it is also easy to produce kinks, resulting in fabric defects and damage to the knitting needle; In addition, the yarn with excessive twist will affect the elasticity of the knitted fabric and cause the coil to skew. However, the twist of knitting yarn should not be too low, or it will affect its strength, increase the end breakage during weaving, and the yarn is soft, making the fabric easy to fuzz and pilling, reducing the wearing performance of knitted fabrics.

Twist selection for different uses: the twist requirements of knitted fabrics are different due to different uses. For example, the undershirt should be smooth, compact, smooth and clean, with clear lines, and the twist of yarn should be larger, which can be close to the warp yarn standard for weaving with the same thread density; The twist of coat yarn should be larger to enhance the straightness and improve the pilling phenomenon; Cotton wool cloth and elastic cloth shall be soft and elastic, and the twist of yarn shall be slightly lower. Generally, the lower twist deviation of weft yarn for weaving with the same linear density is adopted; Yarn used for raising knitted fabric, in order to facilitate the drawing, and make the pile thickness even, the twist requirement is smaller.

Specific methods to improve hand feel:

Twist reduction: For knitted fabrics that require soft and elastic feel, the yarn twist can be appropriately reduced. This will make the yarn more soft and the woven fabric will feel more soft and comfortable. For example, in the production of cotton wool cloth, elastic cloth and other fabrics, the lower twist deviation of weft yarn for weaving with the same linear density is used to obtain better softness and elasticity.

Optimize the matching of twist and fiber performance: when selecting yarn, the matching of fiber performance and twist should be comprehensively considered. For some fibers with good softness, such as cashmere and modal, the twist can be properly reduced to give full play to their softness; For some fibers with high strength but poor softness, such as polyester, nylon, etc., the strength and wear resistance can be improved by properly increasing the twist, and at the same time, it should be controlled within the range that does not affect the feel.

Combined with the finishing process: In addition to improving the handle by adjusting the twist, it can also be combined with some finishing processes to further optimize the handle. For example, the fabric is softened and treated with softener, which can reduce the dynamic and static friction coefficient of the fabric surface and make the hand feel softer and smoother; Alternatively, acid cellulase treatment can be used to remove the fuzz on the surface of the fabric, improve the clarity and smoothness of the lines, and thus improve the hand feel of the fabric.

Low twist yarns on the market can improve the hand feel of knitted fabrics:

The low twist yarns on the market can really improve the hand feel of knitted fabrics. The specific reasons and effect analysis are as follows:

Characteristics of low twist yarn and its influence on handle:

Soft and fluffy: the twist of low twist yarn is more than 20% lower than that of conventional yarn, and its fabric is soft, fluffy but not thin. This is because when the twist is low, the cohesion between fibers is relatively weak, and the yarn structure is relatively loose, which makes the woven fabric feel softer and fuller, giving a comfortable and warm feeling. Pay attention to the deformation of the fabric after washing.

Reduce hairiness: hairiness decreases with the increase of spinning twist coefficient. Low twist yarns have hairiness due to low twist and loose arrangement of fibers in the yarn. However, through reasonable process control, hairiness can be reduced, making the surface of the fabric more smooth and delicate, further improving the hand feel, and paying attention to the hairiness after watering.

The application effect of low twist yarn in knitted fabrics:

Improve comfort: the woven fabric with pure cotton low twist yarn in the same direction has a thick and full visual effect, and its surface density is lower than that of the conventional woven fabric of the same thickness. It has a small wearing burden, high warmth retention, soft and comfortable feel, which greatly improves the comfort of woven fabrics. Similarly, the use of low twist yarns in knitted fabrics can also make fabrics have similar characteristics and improve the comfort of wearing.

Improving wearability: low twist yarn knitted fabric has good wearability, such as 14.58 Tex siro spinning low twist yarn knitted fabric can develop low twist yarn knitted fabric suitable for infant products by changing process parameters such as single yarn cotton blending, coarse and fine yarn twist coefficient. This shows that the low twist yarn can meet certain wearing performance requirements, such as strength and wear resistance, while maintaining a soft feel.

Precautions for production and application of low twist yarn:

Production difficulty and quality control: The production of low twist yarn is relatively difficult, and the product quality is difficult to control. The production enterprise needs to have certain technical ability and management experience. In the production process, it is necessary to ensure the air pressure for untwisting and twisting of the winding drum, and adjust the process parameters such as the lap length, so as to improve the joint quality and reduce the phenomenon of yarn head climbing at the splice.

Reasonable choice of twist direction: the change of twist direction of spinning yarn has little influence on the yarn indexes, but it may have some influence on the fabric due to the weaving process. Therefore, in practical application, the twist direction of yarn should be reasonably selected according to the specific weaving process and product requirements to optimize the feel and performance of the fabric.

To sum up, the low twist yarns on the market can effectively improve the hand feel of knitted fabrics, making them more soft, fluffy and comfortable, while maintaining certain wearability. However, in the process of production and application, attention should be paid to process control and quality assurance to give full play to the advantages of low twist yarns.

Softeners can improve the hand feel of knitted fabrics:

Softener can really improve the hand feel of knitted fabrics, but whether it is environmentally friendly and healthy depends on the type and composition of softener used. The following are some details about the environmental protection and health of softeners:

Environmental protection and health problems of traditional softeners:

Chemical composition: Many traditional softeners contain organic solvents, preservatives and volatile organic compounds (VOCs), which may pose potential risks to the environment and human health. For example, the chemical components in some softeners may cause skin allergy, poor breathing, gastrointestinal discomfort and nervous system abnormalities.

Environmental impact: Some traditional softeners may pollute water and soil, and have a negative impact on the ecosystem.

Development of environment-friendly softeners

Environmentally friendly ingredients: modern softeners have been improved in the formulation and production process. More environmentally friendly ingredients have been used to reduce the negative impact on the environment. For example, some environment-friendly softeners use natural ingredients, which are free of phosphorus, fluorescent agents, and irritant chemicals. They are mild and non irritant to the skin, and can be used even for sensitive skin. At the same time, they have good biodegradability and are environmentally friendly.

Technological innovation: With the progress of chemical synthesis technology and environmental protection concept, softeners have made significant progress in improving efficiency and reducing environmental impact. Softeners on the current market have not only improved in efficiency and stability, but also achieved breakthroughs in cost-effectiveness and ease of use.

Suggestions on selecting environment-friendly softener

Regular brand: When purchasing softener, you should choose a regular brand to avoid using products of inferior quality or unknown source.

Composition inspection: check the product composition, and select products without phosphorus, fluorescent agent and irritant chemicals.

Biodegradability: Select a softener with good biodegradability to reduce the impact on the environment.

Future development trend

Sustainable development: In the future, the development of softeners will pay more attention to technological innovation and sustainability. On the one hand, with the progress of new materials and manufacturing technology, softeners will pay more attention to improving their efficiency and compatibility to meet the needs of more high-performance applications. On the other hand, with the improvement of requirements for sustainable development, softeners will pay more attention to the use of environmentally friendly materials and production processes to reduce the impact on the environment.

In conclusion, softeners can improve the hand feel of knitted fabrics, but in order to ensure environmental protection and health, environment-friendly softeners should be selected.