A. Visual changes to plastic surfaces are negligible. In many cases, there is no discernible visible change. With heavy fluorination, plastic surfaces can become less glossy and slightly mat. Some high gloss resins have been developed that stay glossy after fluorination.

A. All containers should be packed in a way that ensures they stay clean, grease and oil free, and dry. Customers use re-shippers, bulk boxes, tray packs and pallets depending on what best suits their product. Most customers utilize poly bag liners in carton and full height shrink wrap on palletized containers. Larger containers may be individually poly bagged for shipment in a clean truck.

A. The US Department of Transportation requirement for products transported over US highways is that chemicals and solvents lose less than 2% weight per year. This serves to protect warehouse and shipping personnel from excessive fume exposure and to protect the consumer from underweight packaging. Note that for hazardous materials the permissible weight loss is only 0.5% per year! Fluorination can often boost HDPE container performance enough to help you meet these targets. Over 20,000 of our customers worldwide have been able to maintain use of impact resistant HDPE packaging and avoid switching to less desirable glass or metal containers or to more expensive barrier resin or barrier coated containers.

Note That the DOT lists a general procedure for testing chemical compatibility and rate of permeation. This may be helpful for your evaluations and may be found at:
Appendix B.49 CFR Ch. I, Pt. 173, Appendix B.

A. Yes. The Fluoro-Seal Process complies with FDA regulations in accordance with 21CFR Ch. I, Pt. 177.1615 a, b, and c.

Note: The DOT lists a general procedure for testing chemical compatibility and rate of permeation. This may be helpful for your evaluations and may be found at: Appendix B.49 CFR Ch. I, Pt. 173, Appendix B.

Please have your FDA affairs group locate the most recent edition of the CFR and provide you with advice and guidelines in adhering to any and all regulations that may apply to your particular application.

A. Usually yes - but they must be pre-qualified to insure the inks are compatible with fluorination. Fluoro-Seal can work with your decorator to find inks that will successfully undergo fluorination.

A. In most cases, sleeve labels do not prevent containers from being fluorinated. Some printed colors bleach or the sleeve itself may wrinkle during the fluorination process. If sleeve labels are to be used, FSI will perform tests to pre-qualify the sleeve before production orders are processed to assure compatibility of your specific container and a specific printed sleeve.

A. Usually yes - but they must be pre-qualified to insure they are compatible with fluorination. Plastic in-mold labels work best with fluorination.

A. Paper labels often present unacceptable technical problems. If labels are a consideration in your container system, it is essential that you contact FSI to arrange test fluorination of samples to insure compatibility and avoid costly mistakes and delays.

A. Customers report few problems in applying labels to fluorinated containers. Fluoro-Seal recommends that the label and adhesion be part of the compatibility testing done to qualify the package before going into production.

A. Fluoro-Seal has successfully fluorinated every color imaginable, including pearlescent pigments. With some colors there may be slight bleaching and some pigments require higher levels of treatment to attain comparable results with unpigmented bottles.

Product testing is strongly recommended before beginning production to ensure the treatment level specified will meet your requirements.

The most common color for fluorinated bottles is white. Black, brown, red and yellow bottles are also routinely treated, but the number of customers and volumes are lower.

Absolute optimum barrier is always obtained with natural unpigmented resin. With some pigmented bottles, the fluorination level may have to be increased to match the barrier performance attained with an all natural resin container and meet application requirements.

Weight loss testing is always advised and serves as your principle guide to satisfactory performance.

When use of an unpigmented resin is not possible, customers with very challenging packaging applications have chosen to switch to a dual layer bottle with a natural inside layer and trade dress color outer layer. This allows creation of higher barriers than that possible with a pigmented bottle.
It is usually found that monolayer pigmented bottles will prove satisfactory for routine applications.

A. Post-Mold fluorination, as practiced by Fluoro-Seal, also provides other beneficial surface modification effects. We have a growing customer base who fluorinate polyethylene containers in order to boost adhesion of inks, coatings and structural adhesives.

With proper adhesive selection, it is possible to achieve structural bonds, which in T-peel and lap-joint testing, exceed the strength of the base polyethylene.

Unlike flame, arc and corona treatments, which are well known to fade with time, there is no known life time limit for surface fluorination. This enables storage of treated containers with the surety that when they are eventually used, their surface modification will still be effective.

A. Yellowing is a problem experienced in the plastics industry from time to time. It can usually be traced to antioxidants and possibly the presence of other compounds in the formulation or storage environment. Yellowing in the case of fluorinated containers can be experienced although this happens very rarely In polyolefins such as HDPE, LDPE and PP. The cause is usually quinone formulation by the antioxidant package. Some antioxidants are more prone to this than others.

Note that resin manufacturers and suppliers can and have switched antioxidant packages without notifying customers. In fact the antioxidant is typically not even specified in most resin contracts. For optimum fluorination results this is a detail which needs attention.

For more specific information on contaminating factors that can cause yellowing bottles, please contact Fluoro-Seal's technical department in Houston.

Phenolic-based antioxidants, particularly BHT and Irgonox® 1076, are most prone to this. Antioxidants are incorporated into the plastic by the resin manufacturer and thus can be controlled by selection of proper resin type and by contract specifications on antioxidant type and amount. Old resin grades that have been on the market for years and years are usually the ones still using BHT or 1076. Newer grades are turning away from these to 1010, 1330 or 1010 with phosphite 168. The latter give reduced color problems. Note that resin manufacturers and suppliers can and have switched antioxidant packages without notifying customers. In fact the antioxidant is typically not even specified in most resin contracts. For optimum fluorination results this needs attention.


There are alternate contamination pathways into the resin. The most common is regrind addition. Very frequently plant regrind will be collected from many runs and admixed into the virgin resin at a particular few machines. These runs get a sampling of every antioxidant being run in the plant that week. Even though the particular virgin resin may contain no BHT or 1076, it can be introduced through regrind. It is for this reason that we always recommend that regrind be buried into an inner layer using a machine with a three layer dye. Unfortunately this is not always possible, in which case regrind separation is second best, i.e. to only use regrind off the present production, not plant wide regrind. Phenolic antioxidants can also migrate into parts from other sources. Cardboard boxes or box liners can contain phenolic antioxidants and these have been known to transfer to the surfaces of pellets or containers through direct contact and even diffusion through air. Discoloration effects usually show up most severely in white pigmented bottles.

This brings another factor into the picture and that is titanium dioxide which in untreated form is very reactive with antioxidants. Under proper conditions, this pigment can chemically interact with antioxidants and give rise to yellowing or even browning. Numerous sporadic factors have been known to trigger the reaction. Nitrous oxide from fork lift truck exhaust, amine type antistats, contaminants found in some stearate are some of the more common factors.

To counteract pigment/antioxidant reactions, titanium dioxide pigment is offered in several grades. For purposes of this discussion the most important factor is degree of coating over titanium diode pigment particles. Pigment producers have developed coatings of aluminum oxide, silicon dioxide or silane, alone or in combination, which reduce reactions of titanium dioxide with antioxidants. The tradeoff is that the coatings reduce coverage to some degree and require compensation by addition of more pigment to achieve a particular white density. This increases color cost for a given product.