DWK Life Sciences completes your packaging needs with just the right closure. Our comprehensive range of caps and closures ensures a perfect fit for your containers as well as chemical compatibility with your samples. Whether you choose our sterile stoppers and seals, liners or septa, this entire line conforms to GPI (Glass Packaging Institute) standards, ISO and ASTM specifications, as well as European DIN specs.

Aluminum seals, screw thread closures, rubber stoppers and more — whatever cap or closure you need, rest assured it’s made from the highest quality raw materials to deliver exceptional dimensional stability. For your convenience, all are available in bulk quantities and formats and are packed and customized to meet your specific configuration, operational, and run-rate needs. In addition, our closures are available sterile in inventory-matched convenience packs to improve workflow and reduce waste.

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Caps and Closures Complete Your Packaging

The DWK Life Sciences family of caps and closures are manufactured from the highest quality raw materials to ensure that each selection yields dimensional stability as well as exceptional chemical resistance and dependable closure integrity.

Our line is complemented by a diverse screw thread cap selection to provide a total packaging solution for borosilicate and soda-lime glass or plastic containers like low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polyethylene terephthalate (PET). In addition, our stoppers and seals, liners and septa are all offered in PTFE-faced silicone and rubber, and fluoropolymer resin-faced foamed polyethylene rubber. Our PE cone liner formats are available standalone or preassembled in screw thread and our phenolic and poly-vinyl caps come in a variety of colors.

Stoppers are offered in a range of formulations that include multiple beneficial features such as lyophilization support, multiple piercing tolerance, autoclave approved, gas and moisture transmission resistance as well as high heat and chemical resistance. Gray Bromobutyl 39 with CompleteCoat offers low-gas and vapor permeability and can be autoclaved, irradiated and used in applications requiring multiple piercings. Gray Bromobutyl 46 & 47 UltraPure stoppers are latex-free and compatible with WFI applications. They’re also known for good moisture absorption and desorption properties associated with autoclave and lyophilization. PTFE and OmniFlex coated stoppers are manufactured in a silicone-free environment then completely coated with a fluorinated polymer to virtually eliminating chemical reactions due to contact with rubber surfaces. Snap-on stoppers lock into the blowback ridge of a vial to provide maximum sealing and inhibit the stopper from backing out. Straight plug stoppers are known for having low particulate and extractable, making them the perfect choice for ready-to-use and ready-to-sterilize parenteral drug applications requiring extreme gamma irradiation doses. Bromobutyl stoppers are available for larger glass bottles with GL 25 and GL 45 threads. Lyophilization stoppers are offered in an igloo, thin flange, two-leg, three-leg styles to reduce cocking and interlocking and ultimately improve workflow. We recommend that you choose your stopper based on vial mouth IDxOD (mm).

Aluminum seals are available in a wide range of colors and are designed for use with 13 and 20 GPI serum finishes requiring crimp tear off, tear out, center tear, flip off, and open-top solutions. Choose the right aluminum seal based on vial mouth IDxOD (mm). Open-top septa provide direct access to simplify content removal. For your peace of mind, our flip off, tear off, and tear out styles provide tamper evidence. Our flip off can provide multiple advantages including center hole access, closure integrity, and easy one-hand opening that eliminates jagged metal edges and maximizes safe use. If you’re looking for a dependable seal for repeat use, our aluminum center tears out styles maximize seal integrity time after time. Center disc tears-out seals are commonly used with serum or molded vials requiring stopper exposure for syringe access. Solid top seals provide superior protection from evaporation. Magnetic seals are designed for use with automated magnetic handling and crimping systems. Consider one of DWK’s hand crimping solutions for benchtop operations.

Foil-faced liners offer low gas permeability and provide a barrier layer that can protect against aggressive content. Polyethylene foam liners offer good chemical resistance and compress in the cap to prevent leaks for plastic and glass bottles and are our recommendation for threaded containers used in pharmaceuticals, chemicals, and cosmetics applications. PTFE-faced septa are autoclavable, resist coring, and have a handy non-stick characteristic. They’re also well known for their resistance to chemical attack, their excellent resealability, a low coefficient of friction, and strong performance in broad operating temperature. PTFE/Butyl produces a more positive seal and is commonly used with unlined aluminum seals for pharma packaging applications. FEP/Butyl Septa are designed for use with aluminum and threaded finishes, as well as headspace autosamplers requiring the sealing of sample vials in operating temperatures ranging from -60 to 200 C. Cone-shaped LDPE liners provide a two-part seal between the primary package rim and inner surface of the threaded container opening making them an excellent option for sample storage and other applications requiring repeated re-sealing. Pulp vinyl liners are a general-purpose liner having a vinyl coating that is applied to high-density polyethylene layer laminated to pulpboard. Pulp vinyl liners offer good chemical resistance and are commonly used for medical, chemical, and other applications packaged at less than 48°C.

Consider threaded screw closures for containers used for mixing, extended storage, transport, and delivery of liquid media, buffer solutions, culture media, non-hazardous
chemicals, or volatile organic substances and solvents. You have several choices of screw closures including phenolic, urea, PP, PTFE, PBT, PE styles suitable for use with pour rings and a variety of liner options. Threaded screw caps are the perfect choice for applications involving repeated opening and closing and tamper-evident PP screw caps for media and sample storage bottles are available.

PTFE and PREMIUM PFA screw thread caps are chemically inert and remain non-brittle at sub-zero temperatures. Polypropylene screw thread caps are available with an internal molded seal ring and in open-top formats for applications requiring multiple injections. These caps can be used in combination with GL45 bromobutyl rubber stoppers (link to 292062803) and silicone septum (link to 292483005). PBT screw thread caps are suitable for high-temperature applications up to 180C and offer excellent chemical resistance when paired with PTFE-faced silicon liners. Our premium caps made from pigment-free polymer reduce the risk of leaching while our PTFE faced silicone cap liners provide maximum leak tightness. Linerless polypropylene screw thread caps are an economical autoclavable solution with exceptional sealing qualities. Liners can be welded or bonded to eliminate possible glue contamination or cemented for cost-sensitive applications. Pair screw thread cap solutions with PTFE-faced LDPE foam liners to maximize resealability, tinfoil liners for good chemical resistance, pulp-backed for contact with strong oxidizing agents, or cone-shaped liners for sealing while minimizing torque stress.