Detailed Explanation of Core Stitch Types for Warp Knitting Machines

The core advantage of the warp knitting process lies in knitting fabrics with diverse structures and different functions through the scientific matching of various knitted stitch types — from lightweight and breathable underwear fabrics to exquisite and complex lace trims, and to thick and wear-resistant industrial fabrics. The production process is inseparable from the precise control of the warp knitting machine stitch.

This article focuses on the 5 most commonly used core stitch types for warp knitting machines, including Tricot Stitch (1-and-1 lapping movement), Pillar Stitch, Satin Stitch, Fancy Stitch, and Double Loop Stitch. It provides a systematic and rigorous analysis combined with the structural characteristics, knitting principles, and practical application scenarios of each stitch, helping industry practitioners and overseas customers quickly master the core warp knitting technologies.

I. Core Concepts of Warp Knitting Process & Loop Structure Explanation

Before formally explaining specific stitches, we first clarify the core definition of warp knitting stitch: Warp knitting stitch refers to the arrangement and connection structure of loops formed by the coordinated movement of needles and guide bars of the warp knitting machine on the needle bed. Different stitches directly determine the appearance, hand feel, elasticity and application scenarios of the fabric. Among them, Tricot Stitch, Pillar Stitch, Satin Stitch and Double Loop Stitch are the core basic stitches of warp knitting, covering the production needs of most warp knitting fabrics.

In warp-knitted fabrics, the loop is the basic structural unit of the knitted fabric. Its structure is shown below. A complete loop consists of a loop stem (green part) and a sinker loop (red part). According to the arrangement state of the sinker loops at the base of the loop, the loops in warp knitting stitches are mainly divided into the following three forms:

•         Open Loop: The sinker loops at the base of the loop do not intersect with each other;

•         Closed Loop: The sinker loops at the base of the loop cross each other;

•         Double Loop: A single yarn laps and forms loops on two adjacent needles simultaneously in the same course.

II. Tricot Stitch | 1-and-1 Lap

Tricot Stitch is a basic warp knitting stitch in which each yarn alternately laps and forms loops on two adjacent needles. It is the most basic and widely used stitch in the warp knitting process, and also the core knitting stitch of the Tricot Machine. The production of almost all medium and thin warp knitting fabrics is based on the matching of Tricot Stitch. Its name "1-and-1 Lap" is derived from the movement characteristic that the comb traverses 1 needle pitch to complete one loop formation.

According to the difference in comb traverse span and lapping rule, Tricot Stitch is mainly divided into the following three types, which are suitable for fabric needs in different scenarios:

•         2-needle Tricot Stitch (1-and-1 Lap): The comb traverses 1 needle pitch with bidirectional reciprocating lapping, which is the most widely used basic type;

•         3-needle Tricot Stitch (Cord Stitch or 2-and-1 Lap, collectively referred to as 经绒 in Chinese): The lapping notation of the open 3-needle Cord Stitch is: 3-2/0-1//; the lapping notation of the closed 3-needle Cord Stitch is: 2-3/1-0//;

•         4-needle Tricot Stitch (Velvet Stitch or 4-and-1 Lap movement, collectively referred to as 经斜 in Chinese): The lapping notation of the open Stitch is: 4-3/0-1//; the lapping notation of the closed Stitch is: 3-4/1-0//.

2.1 Structural Characteristics

The core structural characteristic of Tricot Stitch is that the coils are arranged horizontally with no obvious difference between the front and back sides. Specifically, it is formed by one or more warp yarns alternately forming loops on two adjacent needles (i.e., 1-1 traverse), forming continuous horizontal coil courses. The coils are arranged horizontally, adjacent coils are staggered with each other, the fabric surface presents delicate horizontal textures, the front and back textures are similar, the overall structure is flat, the air permeability is excellent, the fabric strength is high, the dimensional stability is good, and it is not easy to deform.

Intuitively, the coils of Tricot Stitch are like "small hand-in-hand rings". Each coil is closely connected with the adjacent coils on the left and right, and the fabric surface has a uniform and delicate texture without obvious protrusions or depressions.

2.2 Knitting Principle

During knitting, the guide bar carries the warp yarns to make small lateral swings, and each warp yarn alternately pierces and forms loops on two adjacent needles — for example, after the warp yarn forms a loop on the 1st needle, the guide bar moves 1 needle pitch laterally, and the same warp yarn continues to form a loop on the 2nd needle, cycling repeatedly to form continuous coil courses. Due to the small swing amplitude and simple movement trajectory of the guide bar, Tricot Stitch has high knitting efficiency, is suitable for large-scale mass production, and is the most used basic stitch in the warp knitting industry.

2.3 Illustration Description

2.4 Application Scenarios

With its core advantages of flatness, air permeability and non-deformability, Tricot Stitch is widely used in medium and thin civil fabrics and is the "basic type" stitch in the warp knitting industry. The specific application scenarios are as follows:

•         Underwear fabrics: Lightweight, breathable and skin-friendly, often used as the lining of seamless underwear and vests, balancing wearing comfort and fit;

•         Sports fabrics: Sweat-absorbent, breathable and moderately elastic, suitable for sports T-shirts, quick-drying clothes and other fabrics, which can adapt to the limb stretching during exercise;

•         Home textile linings: Flat and wear-resistant, can be used as the lining of curtains and bedding to improve the texture and durability of home textile products;

•         Garment interlinings: Lightweight and stiff, used for the lining of shirts, suits and other garments, which can effectively improve the garment's appearance and make the clothes more three-dimensional.

III. Pillar Stitch

Pillar Stitch, also known as Columnar Stitch, is one of the three basic stitches in the warp knitting process, parallel to Tricot Stitch. Its name "Pillar" is derived from the structural characteristic that the coils are arranged vertically and in a columnar shape, while "Chain Stitch" intuitively reflects the chain-like series of its coils. Pillar Stitch is rarely used alone and is the core basic stitch forming composite stitches, which is indispensable in the production of warp knitting fabrics.

3.1 Structural Characteristics

The core structural characteristic of Pillar Stitch is: each warp yarn continuously forms loops only on the same needle, and the loops are connected in series vertically to form independent "loop pillars"; there is no direct connection between adjacent loop pillars, and they are only indirectly supported by the coil pillars of adjacent warp yarns. The fabric surface presents clear vertical stripes, the front and back textures are consistent, the fabric structure is tight, the longitudinal strength is prominent, but the transverse elasticity is poor and it is prone to transverse tearing. Therefore, it is rarely used alone and is mostly used as the base layer of composite stitches.

Intuitively, the coils of Pillar Stitch are like "a string of vertically hanging small rings". Each string of rings exists independently and extends vertically, the fabric surface has clear vertical lines, and the hand feel is relatively stiff.

3.2 Knitting Principle

During knitting, the guide bar does not make lateral swings (or only makes very small lateral swings), and each warp yarn is fixed on the same needle to continuously pierce and form loops, forming vertically extending loop pillars. Since the comb does not need to move laterally, its knitting speed is fast, and the coil pillar structure is tight, which significantly improves the longitudinal strength of the fabric; however, due to the lack of direct connection between adjacent coil pillars, the fabric has poor transverse ductility, and the fabric woven alone is prone to transverse tearing. Therefore, it is usually used with other stitches to form composite stitches.

3.3 Illustration Description

3.4 Application Scenarios

Due to its poor transverse elasticity, Pillar Stitch has limited application scenarios when used alone. It is mainly used as the base layer of composite stitches and matched with other stitches to improve the longitudinal strength and stiffness of the fabric. The specific application scenarios are as follows:

•         Base of composite fabrics: Matched with Tricot Stitch to form Tricot-Pillar composite stitch, used for shirt fabrics, curtain fabrics, etc., balancing the flatness and longitudinal strength of the fabric;

•         Decorative fabrics: When used alone, it can be used as decorative stripes for home textile edging, clothing necklines, cuffs and other parts to enhance the three-dimensional sense of the product;

•         Industrial fabrics: Suitable for scenarios requiring high longitudinal strength, such as filter cloth, conveyor belt fabrics, etc., using its characteristic of not being easy to stretch longitudinally to improve fabric durability.

IV. Satin Stitch

Satin Stitch is a basic warp knitting stitch in which each warp yarn is sequentially lapped and knitted on three or more adjacent needles. Different from the flat and stiff characteristics of Tricot Stitch and Pillar Stitch, the coils of Satin Stitch are obviously inclined longitudinally, and the fabric surface has prominent luster and a smooth hand feel. It is a common stitch for mid-to-high-end fabrics, also an important foundation for fancy stitches, and is widely used in lace, decorative fabrics and other scenarios.

4.1 Structural Characteristics

The core structural characteristic of Satin Stitch is: after each warp yarn continuously forms loops on multiple needles, it jumps to another group of needles to continue forming loops, and the coils are arranged obliquely longitudinally, thus forming a satin-like luster. The front and back sides of the fabric surface are significantly different: the front coils are neatly arranged with soft and delicate luster; the back coils are loosely arranged with dark luster and relatively rough hand feel. Different from the "adjacent loop formation" of Tricot Stitch and "same-needle loop formation" of Pillar Stitch, the warp yarns of Satin Stitch adopt the "cross-needle loop formation" method. For example, a warp yarn continuously forms loops on the 1st, 2nd and 3rd needles, then skips the 4th needle and continues to form loops on the 5th, 6th and 7th needles. This cross-needle arrangement makes the coils form an obvious inclination angle, which is the core reason for generating satin luster.

The lapping notation of Satin Stitch has clear specifications: The lapping notation of the closed Satin Stitch is: 5-4/3-4/2-3/1-2/0-1/2-1/3-2/4-3//; the lapping notation of the open Satin Stitch is: 4-5/4-3/3-2/2-1/1-0/1-2/2-3/3-4//.

4.2 Knitting Principle

During knitting, the guide bar carries the warp yarns to make large lateral movements. Each warp yarn continuously forms loops on several adjacent needles (forming loop courses). After completing a group of loop knitting, the comb jumps a certain needle pitch to continue forming loops on another group of needles. The movement amplitude of the comb is significantly larger than that of Tricot Stitch, so its knitting speed is slightly slower, but it can weave a more textured satin fabric surface. According to the number of cross-needles of the warp yarn, Satin Stitch can be divided into 3-needle Satin Stitch, 5-needle Satin Stitch, 7-needle Satin Stitch, etc. The more cross-needles, the softer the fabric surface luster and the smoother the hand feel.

4.3 Illustration Description of Satin Stitch Loop Structure

4.4 Application Scenarios

With its prominent luster and smooth hand feel, Satin Stitch is mainly used in mid-to-high-end fabrics, especially suitable for scenarios requiring high decorativeness. The details are as follows:

•         Lace fabrics: Satin Stitch is the basic stitch of lace fabrics. Combined with jacquard technology, it can weave exquisite lace trims, which are used in wedding dresses, formal dresses, underwear and other products;

•         Decorative fabrics: Used for the surface layer of curtains and sofa fabrics, which can significantly improve the texture and luster of the fabric and highlight the high-end temperament.

•         High-end underwear fabrics: Smooth and skin-friendly, suitable for seamless underwear, silk-like close-fitting clothes, etc., to improve wearing comfort;

•         Home textile decoration: Used for bedding edging, pillow fabrics, etc., to increase product decorativeness and enhance the layering of home textile products.

V. Fancy Stitch

Fancy Stitch is a warp knitting stitch derived from basic stitches such as Tricot Stitch, Pillar Stitch, and Satin Stitch by adjusting the number of combs, lapping rules, or matching different yarns. It has a special appearance and performance and is widely used in mid-to-high-end decorative fabrics, close-fitting fabrics and other scenarios. The following focuses on 4 commonly used fancy stitches in the industry.

5.1 Tricot Velvet Stitch & Reverse Tricot Velvet Stitch

(1) Tricot Velvet Stitch

The lapping notation of Tricot Velvet Stitch has clear specifications: The lapping notation of the front bar is 2-3/1-0//, and the lapping notation of the back bar is 1-0/1-2//. This lapping combination can ensure the stability of the grey fabric structure. If adjusted to front bar:2-3/1-0// and back bar:1-2/1-0// (that is, the needle-front lapping directions of the two combs are the same), the coil structure will be skewed. Therefore, the lapping movement directions of the two combs directly affect the stability of the coil structure.

Core characteristics of Tricot Velvet Stitch: As one of the most widely used fancy stitches in the warp knitting industry, its grey fabric structure has good stability — when the yarn of one comb breaks and causes the coil course to unravel, the sinker loops of the yarn of the other comb can closely connect the grey fabric structure, avoiding the defect that the double Tricot Stitch grey fabric is easy to split into two pieces.

(2) Reverse Tricot Velvet Stitch

The structural characteristic of Reverse Tricot Velvet Stitch (also known as Anti-Tricot Velvet Stitch) is: the front comb adopts Tricot lapping, and the back comb adopts Cord lapping. This structure can effectively reduce the extensibility and curling of the fabric, make the fabric more stiff, and have the advantage of not being easily snagged, which is suitable for fabrics with high requirements on version.

5.2 Atlas Plain Stitch & Tricot Atlas Stitch

(1) Tricot Atlas Stitch

Tricot Atlas Stitch is divided into reverse structure and same-direction structure. The two have different lapping rules and obvious differences in fabric characteristics:

•         Reverse structure: The needle-back lapping of the front bar yarn is extended, adopting 3-4/1-0// lapping movement, and the back bar yarn still adopts 1-0/1-2// lapping movement;

•         Same-direction structure: Adjusted on the basis of the reverse structure, the front bar still adopts 3-4/1-0// lapping movement, and the back bar lapping is changed to 1-2/1-0//, that is, the two combs adopt the same-direction lapping.

Core characteristics of Tricot Atlas Stitch:

•         Reverse structure: The long sinker loops of the front bar are almost straight and closely arranged, and light can be uniformly reflected through the same plane, making the back of the fabric have excellent luster, and the coils are in an approximately upright state;

•         Same-direction structure: The coil structure is obviously skewed, and the long sinker loops of the front bar are easy to pile; during the napping process, the grey fabric will have large transverse shrinkage, and the total shrinkage rate from the on-machine width to the finishing width can reach more than 40%.

Everse Lapping Tricot Atlas Stitch

Same-direction Lapping Tricot Atlas Stitch

(2) Atlas Plain Stitch (Saxony Stitch)

The structural characteristic of Atlas Plain Stitch (also known as Saxony Stitch) is: the front bar adopts Tricot lapping, and the back bar adopts variable Tricot lapping with a needle pitch of 3. For example, the front bar adopts 1-0/1-2 lapping, and the back bar adopts 3-4/1-0 lapping.

Core characteristics of Atlas Plain Stitch:

The fabric is stiff and thick. Compared with Tricot Atlas Stitch, it has better anti-pilling performance and more stable structure, but the hand feel is relatively hard, which is suitable for home textile and garment fabrics with high requirements on stiffness.

5.3 Atlas Pillar Stitch

The knitting characteristic of Atlas Pillar Stitch is: the back comb performs Atlas lapping movement, and the front bar performs Pillar lapping movement. The stiffness of this stitch is better than that of Saxony Stitch, and it has excellent longitudinal and transverse dimensional stability, which is suitable for scenarios requiring high stiffness and stability of the fabric, such as high-end garment interlinings and decorative fabrics.

5.4 Mesh Warp Knitting Stitch

Core definition of Mesh Warp Knitting Stitch: A warp knitting stitch in which adjacent coil courses lose connection in local areas, thus forming meshes of a certain shape on the warp knitting grey fabric. The shape and size of the meshes can be flexibly controlled by adjusting the lapping rules, which is widely used in curtain yarn, wedding veil, sports mesh and other scenarios, with both decorativeness and practicality.

VI. Double Loop Stitch

Core definition of Double Loop Stitch: A warp knitting stitch formed by each yarn lapping and forming loops on two adjacent needles simultaneously in the same course. The guide bar of this type of stitch traverses two needle pitches in front of the needle, forming two loops continuously in the same course. Special appearance effects such as meshes, stripes and concave-convex textures can be formed by adjusting the lapping rules, adapting to various personalized fabric needs.

The lapping notation of Double Loop Stitch has clear specifications: The lapping notation of the open Double Loop Chain Stitch is: 0-2/2-0//; the lapping notation of the closed Double Loop Tricot Stitch is: 1-3/2-0//; the lapping notation of the open Double Loop Tricot Stitch is: 3-1/0-2//.

Double Loop Tricot Stitch is derived on the basis of Tricot Stitch. Its knitting characteristic is: in each course, each warp yarn is lapped on two adjacent needles simultaneously, and the next course moves one needle pitch relative to the previous course; at this time, the coils of one coil course are always formed by one yarn, and the coils of its adjacent courses are alternately formed by the left and right adjacent warp yarns. Double Loop Tricot Stitch can be woven into warp knitting grey fabric with a single comb of one-in-one-out, which has high production efficiency.

On the basis of Satin Stitch and modified Satin Stitch, Double Loop Satin Stitch and modified Double Loop Satin Stitch can be further derived, expanding the application scenarios of Satin Stitch and meeting the diverse needs of mid-to-high-end fabrics.

Core characteristics of Double Loop Stitch:

Due to the large proportion of open loops in the stitch, its performance is between warp knitting and weft knitting, with the advantages of small unraveling and good elasticity, which is suitable for fabrics requiring a certain degree of elasticity and structural stability, such as elastic underwear and sports fabrics.

VII. Comparison Table of Core Warp Knitting Stitches

VIII. Frequently Asked Questions (FAQ)

•         Q: What is the difference between Tricot Stitch and Satin Stitch?

•         A: The core difference lies in the lapping rule and coil shape. Tricot Stitch adopts bidirectional reciprocating lapping between adjacent needles, with upright coils and a flat, matte surface; Satin Stitch adopts one-way continuous lapping with jump needle return, with significantly inclined coils and a satin luster surface.

•         Q: What are the applications of Pillar Stitch in warp knitting?

•          A: Pillar Stitch is rarely used alone and is mainly used as the base layer of composite fabrics to improve the longitudinal strength of fabrics; it can also be used as decorative stripes for home textile edging and clothing details, and is applicable to industrial fabrics requiring high longitudinal strength.

•         Q: What are the characteristics of Double Loop Stitch?

•          A: Double Loop Stitch has more open loops, so its performance is between warp knitting and weft knitting, with the advantages of small unraveling and good elasticity, suitable for fabrics requiring elasticity and structural stability.

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