TAGS: Sustainability / Natural Solutions
An Interview with Shawn Cook, Technical Manager for Polymer Additives at Dover Chemical Corporation
Polymer processing aids (PPAs) help improve the polymer surfaces. Typically these PPAs are fluoropolymers, which are a subset of perfluoroalkyl substances (PFAS). PFAS are under increased public and regulatory scrutiny and are being phased out.
Keeping these regulatory considerations in mind, Dover Chemical has emerged as a significant player with the introduction of its DoverClear™ line of processing aids for polyolefin films. Its key features are:
- better melt fracture
- PFAS and siloxane free
- food contact approval by the FDA
We talked to Shawn Cook, Technical Manager for Polymer Additives at Dover Chemical, to understand the ideas and the chemistries that have led to the discovery of the DoverClear™ product line and how its unique positive properties outperform the fluoropolymer-based counterparts and thus, address the growing concerns around PFAS.
#1 – Can you tell us about the history of Dover and how it began producing specialty chemicals?
Dover Chemical was founded in 1950 as a chlorinated paraffin manufacturer. The operations actually began in a converted chicken coop! In 1975, ICC Industries acquired the company, and it is still part of that family today. In the 1980s, Dover started making liquid organophosphites and solid organophosphites in 1990.
More recently, the business line has expanded into metalworking fluids and other chemistries. While the growth of Dover has made it a global supplier to the “major players” in the chemical industry, we are still small enough to help solve problems on a local level.
#2 – How did Dover take the necessary steps to address the concerns around PFAS?
Dover, like any other chemical manufacturer with good stewardship, has been monitoring the developments regarding PFAS and subsequent pending regulations. More specific to our industry, we know that fluoropolymers were widely used in polyolefin films as polymer processing aids (PPAs). We first noticed that we could offer a suitable replacement in 2018, but we needed to further develop the technology.
Our breakthrough came in 2021 when we approached the problem from a different perspective:
what if the answer does not lie in common plastic additives? We consulted with our metalworking group, with the idea that there are many similarities between the needs of engine wear and the needs of lubricity inside an extruder. We discovered some unique chemistry that not only performed well (or better) as the fluoropolymers but also had some other unique positive properties as well.
However, many polyolefin film manufacturers require all additives to have food contact-grade materials, and understandably, some of the engine wear additives do not have this designation. So our next hurdle was to find chemistries that not only performed but were approved for food contact as well, and then develop those chemistries into a product that is safe, robust, and
completely PFAS-free.
All that was left was to name it, and that is how DoverClear™ was born. We started with
4 commercial grades of DoverClear™, depending on the application and the need.
DoverClear™ 841 is our most powerful PPA, which should work in all polyolefin applications. However, we do offer some less powerful versions if the resins used aren’t particularly tricky or exotic.
#3 – What will be the impact of the proposed ban on PFAS on currently available materials?
PFAS are used because they work, and through the last few decades, they have been found useful in so many areas. PFAS are called “forever chemicals” due to their lack of biodegradability, but in reality, they should be called “everywhere chemicals” because they are in so many high-performing applications. If there is an outright ban, there will be a lot of industries scrambling to find suitable alternatives. The customer has a performance and quality expectation that has to be met – this is the true challenge of
finding alternatives to PFAS.
#4 – Could you share how the DoverClear™ processing aids are different from other commercial options?
DoverClear™ processing aids are based on existing technology as well as technology that is unique to the industry. Many PFAS alternatives have been known for years, but each of them has its downsides:
- They may have been ineffective, cost-prohibitive, and incompatible.
- They have subsequent downstream effects (e.g., reduced printability) on the polymer.
In general, any chemical with a fluorine atom in it is relatively expensive, so when it comes to any resin producer or film manufacturer who may make billions of pounds of product, there has to be a real need for an expensive additive, or else some of these known solutions would already be employed. As we developed the
DoverClear™ line of products, we knew the pros and cons of many of the other solutions, so when it came to setting performance standards, we knew we had to maximize the pros and eliminate the cons.
DoverClear™ is based on organophosphate technology already used in the polymer industry for thermal stability. Therefore, the use of DoverClear™ leads to a “double whammy” of not only protecting the polymer from thermal degradation but also acting as a PPA. I do not believe there is anything else in the marketplace that makes that claim.
Comparing DoverClear™ Processing Aids with Other Commercial Options in Blown Film
#5 – Which applications/polymers do the DoverClear™ series extend to?
The original intent for DoverClear™ was to help with blown film production (
LLDPE) and to ease the processing of recycled plastic (all polyolefins) to help create a better quality recyclate.
DoverClear™ Helps Create Better Quality Recyclate in LLDPE (Source: Dover)
If our contribution was limited to addressing the PFAS issue, we would be content with our efforts. However, we’ve been fortunate to engage with numerous professionals from various industries, all
seeking alternatives to PFAS — remember “everywhere chemicals?” Each of these interactions has been a valuable learning experience, furthering our knowledge and expansion into other industry uses. We’re not resting on our laurels; in fact, we’re already hard at work on other exciting ideas.
#6 – Is Dover planning to launch more grades in the future owing to an anticipated increase in demand?
The current offering of DoverClear™ is our first commercialization. We are working to improve the technology so that we are able to expand the usage beyond our original intent. I would encourage anyone looking to replace PFAS to come and talk to us. It could be that we are already working on that specific problem.
Explore DoverClear™ Range of Polymer Processing Aids
About Shawn Cook
Mr. Shawn Cook is the Technical Manager for Polymer Additives at Dover Chemical Corporation and is responsible for technical service, customer support, polymer applications, and new product development for plastic additives, particularly phosphites and other antioxidants.
Shawn has 25+ years of experience in all aspects of chemical manufacture, R&D, and process development. In addition to plastic additives, Shawn has experience in water treatment chemicals, and antiadhesives.
Shawn received his MS in Organic Chemistry from the University of Memphis in Memphis, Tennessee, and his BS in Chemistry from Old Dominion University in Norfolk, Virginia, with a minor in Applied Mathematics.