Yarn Extrusion and Processing:

Medical textile design and production begins with the medical grade fiber (yarn). The medical device component requirements must be used to determine the appropriate medical yarn and medical textile design. The selection of a specific medical fiber or medical yarn must consider requirements for:

• Absorbency
• Strength
• Permeability
• Tissue in-growth
• Duration of body contact
• Device mechanical properties
• Sterilization
• Creep
• Bio-absorbability

ATEX Technologies extrudes its own polyester fiber, along with other thermoplastic polymers, in-house, customizing it to meet your design requirements. We can control the properties of the yarn, and ultimately the component, by expertly monitoring the entire process ensuring performance and uniformity. WE EVEN HAVE A MASTER FILE ON OUR PET MATERIAL. The ATEX R&D and biomaterials engineering groups have the skill and expertise to assist you in selecting the appropriate medical fiber for your device.

Weaving:

The process of interlacing two yarns so that they cross each other at right angles to produce a woven fabric.  A woven fabric is comprised of warp yarns in the longitudinal (machine) direction and weft yarns in the crosswise direction.  The warp and weft yarns may be the same fiber and same size or they may be different in fiber type and size. Key characteristics of woven fabrics include:

• Dimensional stability
• Controlled porosity
• Diagonal stretch
• High multi-directional strength

The value of woven grafts in an implantable medical device include:

• Low profile design
• Low delivery forces required
• Ease of Deployment
• Resilient
• High degree of coagulation

Knitting: 

Knitting is a method of constructing fabric by interlocking a series of loops of one or more yarns.  Warp knitting is a type of knitting in which the yarns generally run lengthwise in the fabric.  The yarns are prepared as warps on beams with one or more yarns for each needle.  Examples of warp knitting include Tricot, Milanese, and Raschel knitting. 

Key characteristics of knit fabrics include: 

• Dimensional flexibility 
• Conformability 
• Controlled porosity 
• Resistance to un-raveling 

The value of knit fabrics in an implantable medical device may include: 

• High degree of tissue in-growth 
• Controlled degree of elongation 
• Compressibility 
• Inherent Elasticity/Flexibility 

• Macro-porous to minimize infection 
• Soft against tissue 
• High burst strength 

Medical Fabrics can be knit into a variety of shapes based on your biomedical structure’s requirements, including: 

• Flat Sheets 
• Tubes 
• Fenestrated Tubes 
• Double Knit Structures (two layers knit together) 
• Spacer Fabrics (three dimensional structure) 

ATEX possesses the expertise to produce a wide variety of component shapes from a knit fabric. ATEX can also customize any component by employing our extensive fabrication and enhancement capabilities. These include fabric dying and marking, precision cutting and even custom coatings. Learn more about our custom fabrications and enhancements here. 

Braiding:

A process in which three or more yarns are entwined with one another such so that they cross one another to make continuous narrow strands, much like rope. A braid structure or pattern can incorporate flexible materials such as textile fibers, yarns or wire, referred to as ends or carriers on the machine.  The simplest possible braid is a flat, solid, three-end structure. More complex braids can be constructed with additional ends such as an even number of ends to create a wider range of round cords  or hollow structures: wider ribbon-like bands use odd number of ends, and depending on the braid angle, may resemble a woven pattern. 

Key characteristics of braided textiles include: 

• High strength 
• Low profile 
• Versatility  
• Chinese finger cuff ability 

The value of braided textiles in an implantable medical device may include: 

Non Wovens:

Non woven fabrics are made when short and or long fibers are bonded together through chemical, mechanical , heat or solvent treatments. Fabric broadly defined as a sheet or web structure bonded together by entangling medical fibers or filaments (and by perforating films) mechanically, thermally or chemically. They are flat, porous sheets that are made directly from separate fibers or from molten plastic or plastic film. 

The fibers in a non-woven may be oriented in one direction or randomly throughout the fabric.  Multiple layers can be combined to achieve desired strength, elongation and other mechanical properties.  Porosity can be controlled by varying fiber diameter, fiber density, fiber orientation and additional mechanical processing. 

Key characteristics of non-woven fabrics include: 

• Dimensional stability 
• Strength 
• Durability 
• Resilience 
• Low elongation 

Hybrids:

Hybrid fabrics include more than one type of structural fiber in its construction.  Hybrid fabrics allow two or more fibers to be constructed into one or more layers of fabric. In a woven hybrid fabric it is possible to have one fiber running in the weft (crosswise) direction and the second fiber running in the warp (longitudinal) direction.  It is also possible to use a combination of different fiber types in each warp and weft direction. 

Although hybrids are most commonly found in knit fabrics, the principle is also used in weaving, braiding, and non-woven fabrics.  Hybrids are often used for: