HDPE (High Density Polyethylene)

HDPE is the most commonly-used material for producing containers. In its natural state, it produces translucent, milky-colored containers, but can be pigmented to produce virtually any color desired. It is well-suited for a wide range of products, including toiletries and cosmetics, pharmaceuticals, certain food products, and water-based chemicals. This material offers excellent water barrier characteristics. However, its properties are inadequate for products sensitive to oxidation or those products which contain solvents.

LDPE (Low Density Polyethylene)

LDPE is a soft, squeezable form of polyethylene, particularly suited for squeeze spray or dropper applications. Nasal sprays are typical uses of LDPE. Low density polyethylene is very resilient and more resistant to stress cracking than HDPE. Low density polyethylene, however, does not provide as good a barrier to gases or solvents as does HDPE, nor does it withstand product fill temperatures of more than 100 degrees Fahrenheit.

PP (Polypropylene)

Polypropylene is slightly more rigid than HDPE, and in its natural form it is translucent with a yellowish-gray cast. This material exhibits excellent contact clarity (it appears clear when filled with product). It also has excellent impact strength, stress crack resistance, and barrier characteristics and resistance to chemicals equal to HDPE. Polypropylene can be used for hot fill opportunities beyond the limits of HDPE. However, polypropylene tends to become brittle at lower temperature ranges. Because of shrinkage differences, polypropylene cannot be produced in HDPE molds.Widely used polymer for non-wetted parts. Attacked by strong oxidizers, aromatic and chlorinated hydrocarbons.

PS (Polystyrene)

Polystyrene is a highly rigid, glass-like, clear material. Although this material will not shatter, it is very brittle and is easily broken. Containers are light in weight and able to withstand high fill temperatures (180° F). Barrier characteristics are poor with a high permeability rate for water. Polystyrene also has poor gas barrier qualities. P/S is generally used for dry products, which are not extremely hydroscopic in nature. Modifiers can be added to improve the impact strength of the material.

CTFE (Chlorotrifluoroethylene)

CTFE is the generic name for the material produced as Kel-F® and as Aclar®. It is very resistant to all chemicals except THF and some halogenated solvents, and is resistant to all inorganic corrosive liquids, including oxidizing acids. CTFE can be used at temperatures up to 100°C. Swells in ketones.

ETFE (Ethyltrifluoroethylene)

ETFE is the generic name for the material such as Tefzel®. A fluoropolymer used for sealing surfaces, it is resistant to most chemical attack; however, some chlorinated chemicals will cause a physical swelling of ETFE tubing.

FEP (Fluorinated ethylene propylene)

FEP is another member of the fluorocarbon family with similar chemical properties. It is generally more rigid than PTFE, with somewhat increased tensile strength. It is typically more transparent than PTFE, slightly less porous, and less permeable to oxygen. FEP is not as subject to compressive creep at room temperature as PTFE, and because of its slightly higher coefficient of friction is easier to retain in a compression fitting.

PAEK (Polyaryletherketone)

PAEK is the generic name for the family of polyketone compounds. (See PEEK.) PAEK includes PEK, PEEK, PEKK, and PEKEKK, which differ in physical properties and, to a lesser degree, in inertness.

VICI utilizes a range of proprietary PAEK-based composites (PEEK and others) for valve and fitting components. These composites resist all common HPLC solvents and dilute acids and bases. However, concentrated or prolonged use of halogenated solvents may cause the polymer to swell. Avoid concentrated sulfuric or nitric acids (over 10%).

PEEK (Poly-etheretherketone)

PEEK is considered relatively inert and biocompatible. Tubing can withstand temperatures up to 100°C. Under the right circumstances, .005” - .020” ID tubing can be used up to 5000 psi for a limited time, and 0.030” to 3000 psi. Larger IDs are typically good to 500 psi. These limits will be substantially reduced at elevated temperatures and in contact with some solvents or acids.

Its mechanical properties allow PEEK to be used instead of stainless in many situations and in some environments where stainless would be too reactive. However, PEEK can be somewhat absorptive of solvents and analytes, notably methylene chloride, DMSO, THF, and high concentrations of sulfuric and nitric acid. This tubing is highly prone to ”kinking”, or sealing off, if held in a sharp bend over time.

We do not recommend PEEK tubing for critical, hazardous, or long term use, particularly at high pressures.

PFA (Perfluoroalkoxy)

PFA is a fluorocarbon with chemical and mechanical properties similar to FEP.

PPS (Polyphenylene sulphide)

PPS is the generic name for the material produced as Fortron®, Ryton®, and others. It is very resistant to all solvents, acids, and bases.

PTFE (Polytetrafluoroethylene)

PTFE is the generic name for the class of materials such as Teflon®. It offers superior chemical resistance but is limited in pressure and temperature capabilities. Because it’s so easy to handle, it is often used in low pressure situations where stainless steel might cause adsorption. PTFE tubing is relatively porous, and compounds of low molecular weight can diffuse through the tubing wall.

PTFE, glass-filled

This form of PTFE is nearly as inert as the virgin but is much more mechanically stable.

Polyimide, graphite

A graphite-filled polyimide. Due to its brittle nature, it is usually used only for reducing ferrules.

Polyimide, virgin

Not recommended for general use due to its tendency to be sticky and brittle at high temperatures. Often used as a high temperature electrical insulator.

Polyimide, Valcon

A high temperature (350°) graphite-reinforced polyimide composite used for all FS and FSR ferrules (fused silica adapters) and many standard ferrules. Valcon polyimide is specially prepared by a process know as Hot Isostatic Pressing (HIP) prior to being machined into individual adapters. This two step process yields a fused silica adapter with high temperature stability far exceeding that of parts produced by molding. It cannot be used with steam or with bases such as strong alkali and aqueous ammonia solutions.

PVDF (Polyvinylidene fluoride)

PVDF has excellent resistance to most mineral and organic acids, aliphatic and aromatic hydrocarbons, and halogenated solvents. Poor resistance to acetone, MEK, THF, and potassium and sodium hydroxide. Often supplied as Kynar^®.