Nylon 6 CAS 25038-54-4
Chelora Chemicals supplies fibre, film and engineering grades of nylon 6 to spinners, film producers and compounders worldwide, including glass-filled compounds. Every consignment leaves with a batch-specific COA covering relative viscosity, moisture, extractables and mechanical properties, the current SDS and full export documentation.
Also known as: PA6 · Polyamide 6 · Polycaprolactam · Nylon 6 chip · Capron type
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Price, lead time and a sample COA for Nylon 6, usually within one working day. We ship worldwide.
Request a Quote Email the DeskDocumentation
- Batch-specific COA (relative viscosity, moisture, extractables)
- Safety Data Sheet (SDS)
- Transport and export documents
- Third-party inspection on request
- Certificate of origin
What is Nylon 6?
Nylon 6 is the polyamide made by ring-opening polymerisation of caprolactam, a semi-crystalline engineering thermoplastic with high strength, toughness and abrasion resistance.
It is supplied as chip, with grades distinguished by relative viscosity: lower for injection moulding, higher for fibre, film and extrusion.
Applications span textile and industrial fibre, tyre cord, barrier film for food packaging, and glass-filled engineering compounds for automotive and electrical parts.
Nylon 6 absorbs significant moisture — up to about 9% at saturation — and that moisture changes its mechanical properties as well as requiring drying before processing.
Why nylon 6 specifically
- Hydrogen-bonded chains. Amide groups hydrogen bond between chains, giving strength, toughness and abrasion resistance.
- Single-step polymerisation. Ring opening of caprolactam is simpler than the salt chemistry nylon 66 requires.
- Excellent dyeability. Amine end groups take acid dyes readily, which is why nylon 6 dominates carpet and apparel fibre.
- Recyclable to monomer. Depolymerisation back to caprolactam supports genuine closed-loop recycling.
How Nylon 6 is Manufactured
Nylon 6 is made by hydrolytic polymerisation of caprolactam, followed by extraction of residual monomer.
- Caprolactam feed. Fibre-grade caprolactam with tight permanganate number and volatile bases limits.
- Hydrolytic ring opening. A small amount of water initiates ring opening at about 250 °C.
- Polycondensation. Chain growth continues to equilibrium, leaving about 10% monomer and oligomer in the melt.
- Extraction. Chip is extracted with hot water to remove residual caprolactam and cyclic oligomer.
- Drying. Extracted chip is dried, with solid-state polymerisation used where higher viscosity is required.
- Compounding. Glass fibre, heat stabilisers, impact modifiers and flame retardants are added for engineering grades.
Typical Commercial Specification
Figures below are representative of an engineering-grade nylon 6. Fibre and film grades differ — tell us the application and we will send the matching sheet.
| Parameter | Typical Value |
|---|---|
| Appearance | Natural translucent chip or coloured pellets |
| Relative viscosity (96% H₂SO₄) | 2.4 – 3.4 depending on grade |
| Moisture as delivered | 0.1% max |
| Extractable content | To grade, typically 0.5% max |
| Melting point | 220 to 225 °C |
| Tensile strength (dry as moulded) | Typically 70 – 85 MPa unfilled |
| Notched Izod impact | To grade data sheet |
| Amine end group content | To grade, relevant for dyeing |
| Ash content (filled grades) | To the glass or mineral loading |
Physical & Chemical Properties
| Property | Value |
|---|---|
| Chemical formula | (C₆H₁₁NO)ₙ |
| Appearance | Translucent natural chip or coloured pellets |
| Density | 1.13 – 1.15 g/cm³ unfilled |
| Melting point | 220 to 225 °C |
| Glass transition temperature | About 47 °C dry, lower when conditioned |
| Moisture absorption | Up to 9% at saturation, 2.5 to 3% at 50% RH |
| Drying requirement | To below 0.1% before processing |
| Chemical resistance | Excellent to hydrocarbons and oils; attacked by strong acids and phenols |
| Processing temperature | Typically 240 to 280 °C |
| Abrasion resistance | Excellent, among the best of engineering thermoplastics |
| Incompatibilities | Strong acids, phenols, oxidisers, prolonged UV exposure |
Behaviour in the process
Nylon 6's moisture behaviour is unlike almost any other engineering plastic:
- Absorbs up to 9% water. Moisture acts as a plasticiser, raising toughness but lowering stiffness and changing dimensions measurably.
- Must be dried before processing. Moisture above 0.1% causes hydrolysis in the melt, dropping viscosity and mechanical properties.
- Dimensional change with humidity. Parts grow as they condition, which must be designed for in precision applications.
- Rapid crystallisation. Mould temperature strongly affects crystallinity and therefore stiffness and dimensional stability.
Nylon 6 Grades and Alternatives
Nylon 6 is bought by relative viscosity and by filler content, with the application dictating both.
| Material | Origin / type | When it is the right choice |
|---|---|---|
| Fibre-grade nylon 6 | High RV, low extractables | Textile, carpet and industrial yarn |
| Film-grade nylon 6 | High RV | Barrier film for food packaging |
| Injection-grade nylon 6 | Lower RV | Engineering parts and housings |
| Glass-filled nylon 6 | 15 to 50% glass fibre | Structural automotive and electrical parts |
| Nylon 66 | CAS 32131-17-2 | Higher melting point and stiffness; lower moisture uptake but harder to process |
Stated plainly: nylon 6 and nylon 66 are chosen on melting point, moisture uptake and processing window rather than on price. Nylon 6 processes more easily and dyes better; nylon 66 runs hotter and absorbs less water.
Industries We Supply Nylon 6 To
Nylon 6 serves textiles, packaging, automotive and electrical markets.
Where Nylon 6 is Used
Fibre takes the largest share of nylon 6 globally, with engineering compounds and barrier film behind it.
Moisture and property change
Nylon 6 absorbs water from the atmosphere, up to about 3% at normal humidity, and that water plasticises the polymer — raising impact strength while lowering stiffness and growing the part dimensionally. Engineering data sheets therefore quote properties both dry as moulded and conditioned, and designers must use the conditioned figures for parts in service.
Drying and processing
Chip must be dried to below 0.1% moisture, typically four hours at 80 °C in a desiccant dryer. Undried nylon hydrolyses in the melt, dropping viscosity and mechanical properties irreversibly. Mould temperature matters too, because it controls crystallinity and therefore the stiffness and dimensional stability of the finished part.
Need a specific grade, purity and packing format?
Tell us the grade, the grade, relative viscosity and filler content your application requires, the packing format you can receive and the annual quantity. We will come back with a price, a lead time, a sample COA and the full documentation set.
Quality Control & Testing
Every lot is released against a batch-specific Certificate of Analysis with the grade's defining properties, so your incoming inspection can release against the actual material.
- Relative viscosity — the primary grade measure, corresponding to molecular weight.
- Moisture as delivered — confirming the chip was packed dry in moisture barrier packaging.
- Extractable content — residual monomer and oligomer, critical for fibre and film.
- Mechanical properties — tensile and impact, reported dry as moulded and conditioned.
- Amine end group content — for fibre grades, governing dye uptake.
- Ash and glass content — confirming filler loading in compounded grades.
Common Process Problems & Likely Causes
When nylon 6 causes trouble, it is usually moisture, mould temperature or conditioning. This table is the shortcut our technical desk works through before anyone opens a complaint file.
| Symptom | Likely cause | What to check |
|---|---|---|
| Viscosity drop and weak parts | Moisture causing hydrolysis in the melt | Dryer performance and moisture as processed |
| Parts growing or warping after moulding | Moisture absorption during conditioning | Design allowance for conditioned dimensions |
| Stiffness lower than data sheet | Properties quoted dry as moulded, part now conditioned | Conditioned property data rather than dry figures |
| Dye streaks in fibre | Amine end group variation or extractables | End group and extractables figures on the COA |
| Brittleness in service | Over-dried material or excessive regrind heat history | Drying time and regrind ratio |
| Dimensional inconsistency between cavities | Mould temperature variation affecting crystallinity | Mould temperature uniformity |
Packaging, Storage & Shipping
- Standard packing. 25 kg foil-lined bags, 500 to 1000 kg jumbo bags and octabins, all moisture barrier packed.
- Moisture protection. Nylon 6 absorbs moisture rapidly from air; keep packaging sealed until use.
- Drying. Typically four hours at 80 °C in a desiccant dryer before processing.
- Storage. Dry, covered warehousing at ambient temperature on pallets.
- Conveying. Dried chip must be conveyed in dry air; ambient conveying reintroduces moisture quickly.
- Grade segregation. Keep RV grades and filled compounds clearly separated.
- Shelf life. Typically 24 months in sealed moisture barrier packaging.
- Transport classification. Not classified as dangerous goods for transport.
Hazards & Safe Handling
Nylon 6 is an inert polymer with no significant health hazard in normal handling. The practical concerns are molten polymer burns, caprolactam fume at high melt temperature and pellet slip hazards.
- Inert in normal handling. Not classified as hazardous. Chips present no chemical risk in storage or transport.
- Molten polymer burns. Melt at 240 to 280 °C adheres to skin and causes severe burns; use proper PPE at the machine.
- Caprolactam fume. Processing releases small amounts of caprolactam vapour, which irritates eyes and respiratory tract; ventilate properly.
- Hot dryer surfaces. Dryers operate hot; burns from hoppers and ducting are a real risk.
- Slip hazard. Spilled chip is a serious slip hazard; clean up promptly.
- Environment. Pellet loss to the environment is a recognised litter source; containment at every transfer point is expected practice.
Regulatory & Compliance Notes
Nylon 6 is unregulated for transport, with food contact and textile standards applying downstream. The notes below are orientation rather than legal advice.
- GHS classification. Not classified as hazardous.
- Transport. Not classified as dangerous goods. Standard packaged and bulk cargo documentation applies.
- Food contact. Barrier film grades must comply with EU 10/2011 and FDA regulations, with residual caprolactam migration limits.
- Textile standards. Downstream yarn and fabric must meet OEKO-TEX and similar standards.
- Automotive specifications. OEM material specifications apply to engineering compounds.
- Polymer exemption. Polymers are exempt from REACH registration, though caprolactam and additives are not.
We Supply Nylon 6 Worldwide
Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Nylon 6 from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, transport paperwork and freight so the material arrives ready to use.
- Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
- Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged where routing and cargo rules allow.
- Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and the transport declaration issued as a complete set.
- Flexible volumes. From a pallet of bagged chip up to repeat bulk shipments on a supply contract.
- Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.
Buying Nylon 6 from Chelora
We are an independent sourcing and supply partner. For nylon 6 that means settling three things at enquiry: the relative viscosity your process requires, whether a filled compound is needed, and whether food contact or textile certification documentation applies.
- Documentation on every lot. Batch-specific COA (relative viscosity, moisture, extractables), plus SDS and the full transport paperwork.
- Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
- Quantities. From a pallet of bagged chip through to full bulk shipments on contract supply.
- Grade matching. Fibre, film, injection or glass-filled grade at the relative viscosity and extractables level your application requires.
- Inspection. Independent third-party inspection available at loading when the contract requires it.
- Related products. Caprolactam, Nylon 66, Adipic Acid and other feedstocks alongside Nylon 6 from one supplier.
How ordering works
- Send the enquiry. Product, grade or purity, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
- We quote. Price, lead time, packing format and a sample COA, normally within one working day.
- Qualify the supply. For first orders or critical applications, we share the analysis and handling documentation so your technical and safety teams can sign off before you commit.
- Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
- Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
- Ship and document. Filled, labelled and loaded with the full export document set, and tracked through to arrival.
Nylon 6 — Common Questions
The questions our technical desk is asked most often about Nylon 6. If yours isn't here, call or email and you will reach someone who knows the chemistry.
What is the CAS number of nylon 6?
The CAS number for nylon 6 is 25038-54-4, and it is classified under HS code 3908.10. As a polymer it is exempt from REACH registration, though caprolactam is not.
What is nylon 6 used for?
For textile and carpet fibre, tyre cord and industrial yarn, barrier film in food packaging, glass-filled engineering compounds for automotive and electrical parts, and wear parts such as gears and bearings.
Do you supply nylon 6 worldwide?
Yes. Chelora Chemicals supplies and exports nylon 6 worldwide — across Asia Pacific, Europe, the Middle East, Africa and the Americas, as well as throughout India, in moisture barrier bags, jumbo bags and octabins.
What is relative viscosity and how do I choose it?
RV corresponds to molecular weight. Lower RV around 2.4 to 2.7 flows better for injection moulding; higher RV around 3.0 to 3.4 gives the melt strength and tenacity needed for fibre, film and extrusion.
How is nylon 6 manufactured?
By hydrolytic ring-opening polymerisation of caprolactam at about 250 °C, initiated by water, followed by hot water extraction to remove the roughly 10% residual monomer and oligomer, then drying.
Why does nylon 6 absorb so much moisture?
Because the amide groups in the chain hydrogen bond with water. At saturation it takes up around 9%, and about 3% at normal humidity. The absorbed water plasticises the polymer, raising toughness but lowering stiffness and growing the part.
What is the difference between nylon 6 and nylon 66?
Nylon 6 is made from caprolactam in one step; nylon 66 from adipic acid and hexamethylenediamine. Nylon 66 melts about 40 °C higher and is stiffer; nylon 6 processes more easily, dyes better and absorbs more moisture.
Why must nylon 6 be dried before processing?
Because moisture above 0.1% causes hydrolysis in the melt, permanently reducing molecular weight and mechanical properties. Typically four hours at 80 °C in a desiccant dryer is required.
Is nylon 6 hazardous?
No. It is an inert polymer not classified as dangerous goods. The practical hazards are burns from molten polymer, caprolactam fume at processing temperature, and the slip hazard of spilled chip.
Why do my parts grow after moulding?
Because nylon 6 absorbs atmospheric moisture as it conditions, which both grows the part dimensionally and changes its stiffness. Precision parts must be designed to conditioned rather than dry-as-moulded properties.
Can nylon 6 be recycled?
Yes, both mechanically and by depolymerisation back to caprolactam. Chemical recycling supports genuine closed-loop programmes in carpet and fishing net recovery, producing monomer identical to virgin material.
What packing sizes are available?
25 kg foil-lined bags, 500 to 1000 kg jumbo bags and octabins, all moisture barrier packed. Orders run from a pallet of bagged chip up to full container loads.
Ready to source Nylon 6?
Send us your specification, grade and annual volume. You will get a price, a realistic lead time and a sample COA from someone who understands what the material has to do in your process — delivered anywhere in the world.