Sewing thread materials explained: fibres, properties and applications

Intro

Not every textile raw material is suitable for the production of sewing threads. Only a few meet the high requirements placed on sewing threads by the sewing process and subsequent use. In addition to construction and fineness, the properties of a sewing thread are determined by the choice of raw material. The raw material has a decisive influence on the performance profile in terms of tear and abrasion resistance, elasticity, sewability, colour fastness and much more.

Modern sewing processes place extreme demands on sewing threads. For example, in a double lockstitch, the sewing thread is pulled through the eye of the needle 70 to 80 times until it is sewn. In addition, it is subjected to sudden stress when the sewing machine starts and stops. Sewing threads must also meet all requirements for abrasion resistance, tear resistance, etc. in subsequent use. The most important raw materials used by AMANN for sewing threads are described in more detail in the following.

The following wiki subpages provide a more detailed overview of the various raw materials used in the production of threads.

Cotton (CO)

The seed hairs of the cotton plant are processed through various production steps to form a fibre fleece (rovings), which is then spun into a finished yarn.

The longer the fibres, the more valuable and the higher the strength
Shiny after mercerisation
Low tear resistance
Low elasticity
Medium moisture absorption
High tendency to crease
Resistant to organic solvents, loss of strength due to strong alkalis, dissolution and decomposition by acids

decomposes or ignites at 400°C, does not melt, burns easily, smells like burnt paper

Polyester (PES)

Polymer formation takes place through polycondensation. The fibre is obtained through the melt spinning process.

Very high tear and abrasion resistance
High elasticity, low crease sensitivity
Very good resistance to light, weather and putrefactive bacteria
Easy care (easy to wash and quick drying)
Hardly any moisture absorption
High temperature resistance compared to other synthetic fibres
Low specific weight

Dry heat resistance: up to 150°C
Melting point: 250°C to 260°C depending on type

Polyamide (PA)

Polymer formation occurs in PA 6.6 through polycondensation and in PA 6 through polymerisation. The fibre is obtained through the melt spinning process.

Very high tear and abrasion resistance
High elasticity, low crease sensitivity
Seawater and rot bacteria resistance
Easy care (easy to wash and quick drying)
Good moisture absorption
Thermoplastic
High light sensitivity

Melting point: PA 6.6 approx. 255°C to 260°C depending on type
Melting point: PA 6 approx. 215°C to 220°C depending on type

Meta-aramid (M-AR)

Meta-aramids are produced by polycondensation and spun using a dry spinning process.

Modified polyamide (aromatic)
Flame-retardant, self-extinguishing, non-melting
Good resistance to acids and alkalis
High resistance to fungi and bacteria
Good abrasion resistance

Continuous temperature resistance up to approx. 220°C
Decomposition temperature: approx. 370°C

Para-aramid (P-AR)

Para-aramids are manufactured by polycondensation and spun using the wet spinning process.

Modified polyamide (aromatic)
Very good cut resistance
Flame-retardant, self-extinguishing, non-melting
Good resistance to acids and alkalis
High resistance to fungi and bacteria
Low loop strength
Sensitive to UV radiation – prolonged exposure to light causes yellowing and a loss of strength of up to 75%

Continuous temperature resistance up to approx. 170°C
Decomposition temperature: approx. 425°C

Polyethylene (PE)

Polymerisation is used to form the polymer. The polyethylene fibres are produced using a melt spinning process.

High abrasion resistance
High alkali and acid resistance
Good rot resistance
Low density

Melting point: approx. 160°C to 175°C depending on type

Polypropylene (PP)

Polymerisation is used to form the polymer. The polypropylene fibres are spun using a melt spinning process.

Similar to polyethylene (PE)
Low density
High resistance to alkalis and acids; soluble in chlorinated hydrocarbons at 70°C (toluene, xylene)
Good resistance to decay
High electrical insulation capacity

Melting point: approx. 160°C to 175°C depending on type

Polytetrafluoroethylene (PTFE)

The polymer is formed by polymerisation. The polytetrafluoroethylene fibres are manufactured using a process known as matrix spinning, a type of wet spinning process.

Very high heat resistance
Very high chemical resistance; insoluble in organic solvents
Very good UV, weather, rot and moth resistance

Decomposition temperature: approx. 325°C

Polytrimethylene terephthalate (PTT)

Polymerisation takes place through polycondensation. The fibre is obtained through melt spinning.

High elasticity
Soft feel
Resistant to yellowing
Extremely durable
Excellent stretch and rebound properties
Good crease resistance
Biopolymer with a proportion of renewable raw materials and energy-reduced production

Melting point: approx. 225°C

Polyetheretherketone fibres (PEEK)

The polymer is formed by polycondensation. The fibres are obtained by melt spinning.

High temperature resistance
Good radiation and chemical resistance
High rigidity

Continuous temperature resistance up to approx. 250°C
Melting point: approx. 330°C

Carbon fibres

Manufacture by thermal treatment (carbonisation) of suitable carbon-containing materials, such as polyacrylonitrile or viscose.

High strength and rigidity
Relatively low density

In combination with oxygen: oxidation (loss of strength) from approx. 400°C
Stable up to 3,000°C in the absence of oxygen
Different temperature resistances as sewing thread, as carbon fibres are only used as sewing thread in combination with other raw materials