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technical guide

FRequently asked questions

Find answers to the most frequently asked questions.

Fluoroplastics & Technical Properties
What is PTFE?

PTFE or Polytetrafluororthylene is the grandfather of all fluoroplastics. It is the most unusual and exhibits the best performance in terms of temperature and chemical resistance, and non-stick properties.

Its major disadvantage is that it does not actually melt when heated and therefore is difficult to process, and very unconventional techniques are needed to mould, extrude and weld this fluoropolymer.

Trade names: Teflon®, Fluon, Hostaflon.

Teflon® is the registered trademark of Du Pont de Nemours.

What is FEP?

FEP or fluorinated ethylene propylene is a co polymer of hexafluoropropylene and tetrafluoroethylene and is a melt-processable polymer. FEP is very similar in composition to PTFE and PFA.

FEP tube has excellent chemical resistance, low coefficient friction and a very high working temperature of 200°C. It is softer than PTFE but is highly transparent and resistant to sunlight.

FEP is regularly used for laboratory tubing applications that involves critical or highly corrosive processes. Other applications are auto sampling, chromatography, medical devices, insulation of high temperature cables.

What is PFA?

PFA or Perfluoroalkoxy is a melt-processable fluoropolymer which can be injection, compression and transfer moulded.

PFA has most of the physical and chemical properties of PTFE, but it has 10 times the flex life and less permeation. PFA has a high temperature range of +260 °C and has an outstanding crack and stress resistance and a low coefficient friction.

PFA is widely used in the semi-conductor industry where high ionic purity, excellent electrical properties and a high working temperature range are essential. Typical products include insulating bushes, nozzles, o-rings and valve and pump linings.

What are the differences between PTFE and FEP?

PTFE and FEP belong to a group of fluoroplastics know as Teflon®, which is a registered trademark of Du Pont de Nemours.

Both PTFE and FEP have very similar characteristics as they are non-stick, chemically inert and remain stable whilst working at extremely low and high temperatures.

The main difference between the two are:

  • PTFE working temperature range is -200°C to +260°C.

  • FEP working temperature range is -200°C to +200°C.

  • PTFE is opaque in colour and FEP is optically clear.

Do PTFE, FEP and PFA become brittle at low temperatures?

No, all of these fluoroplastics, including PFA, have a working temperature range down to -200°C. This temperature range does not embrittle the material.

Does UV penetrate FEP?

Yes, FEP is excellent at transmitting UV as around 4% of UVA transmission is absorbed by the FEP and approximately 15% of UVC. 

Adtech commissioned NRPB to carry out extensive testing of our 0.25mm and 0.5mm thick FEP coatings, that are used as shatterproof coatings for insect killing applications (UVA) and sterilisation and curing (UVC) applications.

UV radiation is notoriously harmful to polymers and many are found to be totally useless, as they mostly age with the dose of UV radiation so that they receive discolouring, and worse, become brittle. The most successful have been found to be the fluoropolymers containing high amounts of the -CF2- and -CF3 in the molecule chain, and the very best appear to be the completely fluorinated polymers.

Which fluoroplastics can be thermoformed?

It's possible to thermoform all fluoroplastics; the most commonly used are PTFE, FEP and PFA. 

With our novel fabrication techniques we can form our PTFE, FEP and PFA tubing into retractable coils, closed end tubes and heat shrinkable covers.We can also form the tubing into complex bent profiles and with flanged ends.

Find out more about Thermoforming Fluoroplastics.

Can fluoroplastics be bonded with epoxy?

Yes. Although fluoroplastics such as PTFE, FEP and PFA are known and chosen for their excellent non-stick properties, there are occasions when they may need to be bonded.

To enable the bonding process, the fluoroplastic has to be chemically etched. This process changes the surface of the material by stripping away the fluorine atoms, thereby making it a bondable surface. We recommend the use of a 2 part epoxy adhesive.

We offer chemical etching of all fluoropolymers and we can etch the ID, OD and dip etch the ends of PTFE, FEP and PFA tubing. Small components can be etched all over and alternatively we can etch parts in only the areas required.

We can offer a fast turnaround and small production batches can be accommodated.

Find out more about Fluoroplastic Chemical Etching.

Why would PTFE be chemically etched?

PTFE, FEP and PFA are extremely lubricious and therefore offer excellent non-stick properties. However, this is a problem should you wish to bond these materials to a substrate.

By chemically etching the PTFE or any of the other fluoropolymers we offer you strip away the fluorine atoms, which then provides a suitable surface for bonding.

Find out more about Fluoroplastic Chemical Etching.

How can PTFE be sealed?

There are numerous techniques for closing the ends of PTFE, FEP and PFA tubes and heat shrinkable products. In most cases, we use a welding process to do this.

Find out more about Welding & Sealing of Fluoroplastics.

How can standard PTFE tubing be made more wear resistant?

By adding a ceramic filler to the PTFE polymer prior to extrusion, the characteristics of the material can be changed to make a PTFE tube more wear resistant.

Different fillers include:

  • Carbon: More wear resistant and anti-static

  • Ceramic-filled: More wear resistance

  • Anti-static: As specified

To discuss your requirements, email our customer service team.

How can standard level detection probes be made non-stick?

A level detection probe can be made non-stick by applying an FEP heat shrinkable closed end probe cover or a plugged and welded PTFE tube.

FEP, PFA and PTFE tubing and heat shrink have an extremely lubricious surface, which make them an excellent choice for non-stick applications. They also have a working temperature change of -200 °C to +260 °C and have the added bonus of being chemically inert.

Find out more about Fluoroplastic Coated Probe Covers.

How can temperature sensors be made chemically inert?

By applying a coated probe cover, a temperature sensor is made chemically inert. Our probe covers are made from heat shrinkable FEP and are extremely easy to apply to standard off the shelf temperature sensors and thermocouples.

Alternatively we can apply an FEP, PFA or PTFE coating to your free issue sensors and offer a fast turnaround.  All of our coatings are spark tested to ensure the integrity of the sealed tip.

Find out more about Fluoroplastic Coated Probe Covers.

How can rubber rollers be made non-stick?

By applying an FEP heat shrinkable coating, a rubber roller is made non-stick. Our FEP roller coatings have been specifically designed to suit most standard sizes of rubber rollers. They are easy to apply and turn a standard rubber roller into a non-stick roller.

Our FEP roll covers are generally available from stock, for you to apply yourself, or we can offer a coating and on site fitting service if required.

Find out more about FEP & PFA Roll Covers.

Which gas sample bag should be used for VOC (Volatile Organic Compound) testing?

Tedlar® bags are widely used for VOC testing and may be used to collect samples containing common solvents, sulfur compounds, hydrocarbons, biogenic and atmospheric gases, chlorinated solvents and many other classes of compounds. 

Low molecular compounds such as Helium and Hydrogen can diffuse through the Tedlar® bag material resulting in poor storage stability.

Find out more about Tedlar® Gas Sample Bags.

Our Fluoroplastic Products
Can you make a close tolerance PTFE tube?

Yes. If our standard tolerance PTFE, FEP, & PFA tube is not suitable for your particular application, we can produce to much tighter tolerances on either the ID, OD or wall thickness. 

To discuss your requirements, email our customer service team.

Can you produce extruded profiles in PTFE?

Yes, we can offer bespoke extruded PTFE profiles and multi-lumen PTFE tube.

To discuss your requirements, email our customer service team.

Can you make a non-standard size of heat shrink tubing?

Yes, if your requirement is outside our standard range, a bespoke size of heat shrink can be produced.

Customers using more than 1000 metres per year of FEP heat shrink may benefit from cost savings by having a custom-made size.

Find out more about Fluoroplastic Heat Shrink Tubing.

What is the largest size of heat shrinkable tubing you can produce?

There is no largest size! By using a special welding process we can form heat shrinkable tubing of any diameter from sheets of plastic. 

Find out more about Fluoroplastic Heat Shrink Tubing.

What are the operating temperatures for heat shrink sleeving?

We offer a range of heat shrink sleeving for general purpose and high temperature applications.

FEP and PTFE heat shrink is designed for use in high temperature and aggressive applications. It has excellent chemical resistance, insulation and non-stick properties.

General-purpose polyolefin heat shrink is a more cost effective solution for less aggressive applications.

Working temperatures:
  • PTFE heat shrink works at -200°C to +260°C

  • FEP heat shrink works at -200°C to +200°C

  • Polyolefin heat shrink works at -55°C to +175°C

Find out more about Fluoroplastic Heat Shrink Sleeving.

How do I shrink heat shrink sleeving?

We recommend the use of a standard hot air gun to shrink our FEP and PTFE heat shrink sleeves.

FEP heat shrink sleeving only requires a shrink temperature of 110°C, so it is perfect for applying to temperature sensitive components.

PTFE heat shrink needs a much higher shrink temperature of +330°C.

Find the Fitting Instructions for PTFE and FEP Heat Shrink.

Adtech specialises in fluoroplastics, but do you work with other plastics?

Yes, where the requirement is specialised and our production techniques are suitable, we often work with other plastic materials.

For example, one of our customers required bags made from flexible PVC film - the quantity was modest, but the quality and design requirements were very high.

To discuss your requirements, email our customer service team.

Is your PTFE, FEP and PFA tubing REACH compliant?

Yes, all of our fluoropolymer products are compliant to REACH Regulation EC 1907/2006 which came into force in June 2007, and the SVHC list (substances of very high concern) was updated in August 2019.

A copy of our REACH statement can be found in our Policies & Statements.

Is your PTFE, FEP and PFA tubing RoHS compliant?

Yes, all of our fluoropolymer products are compliant to the EU directive 2011/65/EU (RoHS II).  A copy of our RoHS statement can be found in our Policies & Statements.

Our Services
What are your opening hours?

Our customer service department is open Monday to Thursday 8.30am to 5.00pm and Friday 8.30am to 2.00pm.

Our goods in department in Stroud is open from Monday to Thursday 7.00am to 4.00pm and Friday 7.00am to 1.00pm.

Our goods in department in Lochgelly is open from Monday to Thursday 8.15am to 5.00pm and Friday 8.00am to 12.30pm.

We are closed on bank holidays.

Do you have a minimum order quantity?

Yes, for stock items, our minimum order value is £100.00. However, we are happy to supply orders below this, but a small order charge of £35.00 is incurred.

Will you supply one-off or small quantities?

Yes, we will supply any quantity of our standard products, and we are happy to make one-off quantities. We simply charge for the set-up time that may be necessary.

To discuss your requirements, email our customer service team.

Will you help or offer advice to us on the design of a new concept?

Yes, yes, yes! It saves time and money for us and our clients to involve us at as early a stage of your development project as possible.

To discuss your requirements, email our knowledgeable customer service team.

What are your standard carriage charges?

Our standard carriage charges are as follows:

  • UK next day delivery service: £14.00

  • Two day delivery service for a parcel up to 20 kilos: £12.00

  • Timed delivery services can be offered if required.

  • When the consignment is small enough, we can ship via Royal Mail's standard and special delivery services.

  • We can also supply bulk goods on pallets if required.

For more information, email our customer service team.

(as at 12/12/2019)

Do you offer international shipping?

Yes, we regularly ship our goods worldwide and we have a range of delivery services available:

  • Express courier

  • Economy courier

  • Standard air mail

  • International signed for airmal 

We can also arrange collection using your preferred carrier or freight forwarder.

For more information, email our customer service team.

Do you have an agent in my country?

We prefer to work directly with customers, as most of our products are of a special technical nature and need direct dialogue. At present, we have direct customers in all continents of the world (except Antarctica). However, we do have working partners in Scandinavia, Benelux, Germany, France, who can work locally for us where necessary.

To discuss your requirements, email our customer service team.

Do you have any vacancies at Adtech?

We carefully select candidates to join our team and are always interested in hearing from people with a technical background in fluoropolymers, engineering and customer service. 

Current vacancies can be viewed in our News.

To send us your interest, email Samantha Deverell.

If you require more information or advice, contact our responsive and knowledgeable customer service team:

Email us