Closure Systems International - CSI

Child-resistant (CR) closures exist for a straightforward reason: to make certain products significantly harder for young children to open while remaining manageable for adults.

In the U.S., the Consumer Product Safety Commission governs CR packaging under the Poison Prevention Packaging Act. Mandatory categories include prescription and OTC pharmaceuticals, pesticides, and certain household chemicals. The standard is precise: difficult enough for children under five, manageable for adults. Compliance documentation is required.

For OTC and nutraceutical brands, child-resistance, line performance, and sustainability all have to work together. CSI's Defender-Lok™ is a next-generation CR closure engineered to deliver all three.

Learn more: bit.ly/4xlx1cZ

Consumer confidence starts before the product is ever opened.

Tamper-evident (TE) closures are designed to signal clearly — visually and audibly — whether a package has been accessed prior to purchase. In many categories, they're not optional. They're a regulatory requirement.

Common TE formats include the snap ring familiar on water and carbonated beverage bottles, foil seals bonded to the underside of the cap, welded membranes with pull rings common in dairy and juice, and combination systems that layer multiple features for pharmaceutical and nutraceutical applications.

Regulatory requirements for TE packaging vary by product category and jurisdiction. In the U.S., both the FDA and CPSC have relevant guidelines depending on product type.

Learn more: bit.ly/4yMNR6e

Matching closure to fill process is one of the most consequential compatibility decisions in packaging development.

The range of fill processes in use today is broad: cold fill, hot fill, hot fill with pasteurization, retort, aseptic, ambient, nitrogen pressure, carbonation, ESL, and HPP.

Each one places different demands on the closure. Temperature resistance, pressure retention, and hermetic sealing requirements all shift depending on how the product is filled and sealed.

CSI closure specifications in design perform flawlessly from a cold-fill environment to a hot-fill or retort application.

When it comes to closures being the right fit for packaging, size isn't just a number — it's a compatibility decision. Closure diameter is measured in millimeters, and the fit between closure and bottle finish has to be exact. Too loose or too tight, and you're looking at application failures or seal integrity issues on the line.

Smaller caps, like 18mm closures fit well on single-serve spirits bottles. But closures go all the way to 133mm for wide-mouth food jars. The right starting point is always your bottle finish spec. From there, you can narrow by diameter, thread profile, and fill process to find closures that are actually compatible with your application — not just close in size.

Try CAPFINDER: csiclosures.com/capfinder

Did you know the term “bottle finish” is actually a critical engineering specification?

The bottle finish is the entire area above the container's neck — the lip, collar, and thread profile. It defines how a closure threads onto, snaps over, or crimps to a container. A proper match between finish and closure delivers a reliable seal and consistent application performance at line speed.

Bottle finish specifications are defined by Industry-standard finish codes governed by bodies like the Glass Packaging Institute and ISBT. These codes give closure manufacturers and bottlers a shared standard reference for compatibility.

Getting the finish spec right before closure selection isn't a formality. It's the starting point for everything that follows.

This Fourth of July marks a milestone 250 years in the making — a quarter-millennium since the founding of the United States.

Our team at CSI is proud to be part of an American story built on craftsmanship, innovation, and hard work. As we celebrate this historic anniversary together, we're reminded of how far this country has come, and we’re grateful for the opportunity to keep building toward what's ahead.

Wishing everyone a safe and meaningful Independence Day.

Material selection is one of the most foundational decisions in closure sourcing — and it affects everything from sealing performance to sustainability outcomes.

The two primary materials in plastic closure manufacturing are:
• Polypropylene (PP) — more rigid, typically used with liners when pressure retention is required.
•Polyethylene (PE) — more flexible, generally seals without an additional liner.

Choosing the right closure material is only part of the equation. Fill process, container finish, capping equipment, line speed, sustainability goals, and cost all factor in. A hot-fill process, for example, requires greater temperature resistance. Applications needing pliability point toward a more flexible resin.

For brands with sustainability targets, nearly all CSI stock closures are available in PolyCycle PCR resin — so performance and circularity goals don't have to compete.

Learn more: bit.ly/3SvdBB9

Caps and closures serve a much broader range of markets than just water bottles. CSD, NCSD, food, liquid dairy, OTC pharmaceuticals and nutraceuticals, and automotive fluids — each have its own performance, safety, and material requirements. CSI serves all of them — and has the stock closure portfolio and application expertise to match.

A closure isn't just a cap. It's the point of contact between your product and the consumer.

Read the full blog: bit.ly/3S7nsPL

Now in its 30th year, National Safety Month is a reminder that every organization has a role to play in keeping people safe — at work, on the road, and at home.

Across our eleven manufacturing sites, Environmental Health & Safety guides how we operate, produce, and take care of each other. This year, the National Safety Council is focused on four priorities that hit close to home for any manufacturer: strengthening the culture of safety, reducing risk on the roads, supporting the whole worker — mental, physical, and emotional — and preventing the slips, trips, and falls that account for so many preventable injuries.

Let’s work to stay safe together.

June is National Dairy Month. For 85+ years, we have celebrated those behind every gallon of milk, from farm to fridge. CSI is honored to help leading dairy brands bring liquid dairy products to consumers safely and reliably.

A few reasons real dairy still matters:
• 98% of U.S. dairy farms are family-owned and operated
• Milk delivers 13 essential nutrients
• It’s essential for lattes, cappuccinos and flat whites!

To the dairy farmers who show up before sunrise every day — thank you.