The Differences Between Calendered and Extruded Vinyl Films

There are two main ways to produce vinyl films: calendering and extrusion. Each of these industrial processes can be used to produce a range of film and sheet products with distinct qualities. As with any manufacturing process, there are advantages and disadvantages to each approach.

What is Calendering?

In calendering, raw materials enter a mixing chamber where they are melted. This molten plastic then moves through a series of heated rollers that compress the material to the desired thickness. Finally, it passes through a series of surface conditioning and cooling rolls, then is wound into custom rolls or cut into sheets.

Calendering Pros and Cons

On the plus side, calendering allows high run rates on films 6 to 60 mils thick. Calendered material typically has higher tensile properties, product uniformity, and unusually close gauge control when compared with extruded films. The added mixing in the process is ideal for highly filled applications and materials, and has the additional advantage that melt degassing occurs in the process. Finally, materials with lower melt temperatures can be used in calendering due to the high pressures used between rollers.

On the downside, calendered products may have issues with pinholes at gauges less than 6 mils, and there may be appearance issues. The rollers used may create surface blemishes and edge buildup on the melt path can create black specs. Also, the sheets are usually less glossy than extruded materials. Calendering is a process that is typically not economically profitable for short production runs.

What is Extrusion?

In extrusion, mixed plastic compound is conveyed through a heated barrel using a spiral shaped screw, converting it into molten plastic. A lip die flattens the mass into a sheet of the desired width and thickness, which then passes through heated embossing rolls that impart a surface finish. The sheet is then trimmed to its final dimension.

Extrusion Pros and Cons

Extrusion offers a number of advantages. Even at thinner gauges, extruded film is pinhole free and has improved “lay flat” qualities. The extrusion process is more flexible, allowing faster changeovers for smaller production runs. The process also delivers better dimensional stability in both machine and cross web directions, and screws can be designed for specific formulations to help improve film characteristics. Finally, the streamlined melt flow reduces black specks.

A disadvantage of extrusion is the requirement for higher melt temperatures. There can also be poor mixing on highly filled formulations. Finally, melt degassing can be a production issue.

Presco Uses Extrusion to Produce Its Presco Engineered Film

Presco compounds and extrudes the flexible vinyl film known as Presco Engineered Film, which is custom formulated to the exact specification of our customers. And in 2017, Presco added Ethylene Vinyl Acetate (EVA) film extrusion to its capabilities as an option for PVC-free manufacturing. To learn about our capabilities, click here.

Follow us on social media for the latest updates in B2B!

Image

Latest

remote leader
Thriving as a Remote Leader with Jared Johnson | Ep. 16 | Growthwell with Josh Byrdjosh
November 7, 2024

As remote work establishes itself as the new norm in today’s demanding business world, balancing career and well-being has become a challenge for many professionals, especially those stepping into the role of a remote leader. According to the American Psychological Association’s (APA) 2023 Work in America Survey, 57% of workers report negative effects due…

Read More
executive summit
Coupa’s Global Executive Summit Promo
November 6, 2024

Discover the value of margin multipliers with Coupa at our Executive Summits. Join leaders in finance, procurement, IT, and supply chain management to explore how Coupa’s solutions can transform total spend management. Gain insights into industry benchmarks, key procurement and finance priorities, and the latest trends in AI adoption and growth. Connect with top executives…

Read More
Gerald Hill
The Blessings of Being There: Insights from Gerald Hill
November 6, 2024

Join us on the Grand Dads podcast as we delve into the rich family life and multigenerational lessons of Gerald Hill, a great-grandfather whose life experiences offer invaluable insights into parenting and community engagement. From starting out as young parents in college to navigating careers and community responsibilities, Gerald and his wife have fostered…

Read More
ICN: Investing in the Future of the Global Nurse Workforce | Howard Catton | EP04
ICN: Investing in the Future of the Global Nurse Workforce
November 6, 2024

In the latest episode of Care Anywhere, host Lea Sims sits down with Howard Catton, CEO of the International Council of Nurses (ICN), to discuss the state of the global nursing workforce. As a respected figure in global nursing, Howard shares insights from ICN’s recent findings, addressing a projected global shortage of 13 million…

Read More