Technical Data
174
Closure Liner Guide Usually the smallest component part of the package and usually overlooked is the selection of the closure liner. The liner must not alter or be altered by the product. It must withstand repeated applications and removals against the container surface while maintaining the integrity of the sealing surface. Below is information that may help in choosing the right liner from the WHEATON product offering.
One mil poly-vinyl film bonded to one mil HDPE on a #30 white pulp paper backing. Superior to plain pulp paper because it provides an excellent moisture barrier. PTFE faced foamed polyethylene liner offers the excellent chemical resistance of PTFE with the compressibility and sealing properties of polyethylene foam. Manufactured from polyethylene (LDPE). The unique cone design provides a wedge type seal that not only seals across the top but also across the inside diameter. The 14B white rubber lining material consists of homogeneous sulfur cured styrene-butadiene rubber. FDA Status complies with 21CFR 177.26, “Rubber articles intended for repeated use.” The white rubber / 0.005" PTFE liner consists of virign PTFE bonded to the white sulfur cured styrene-butadiene rubber. Complies with the FDA 21CFR 177.1550.
General purpose: Suitable for wide range of applications. Chemical resistance: Good for mild acids, alkalis, solvents, alcohols, oils and aqueous products. Poor for active hydrocarbons and bleaches. Typical applications: analytical lab samples, high purity chemicals, strong acids, solvents. Excellent for environmental samples, pharmaceuticals and diagnostic reagents. Unique problem solving type of liner. This liner is stress crack resistant and offers superior torque retention and excellent sealing characteristics. It is recommended that this liner be tested prior to use for leak seal. Excellent properties of resilience, resistant to moisture vapor. Satisfactory for most moderate chemicals. Not good for oils, strong acids and hydrocarbons. Not a natural rubber. Autoclavable. Designed for the ultimate in product safety. PTFE provides a totally inert inner seal and surface facing the sample or product. Autoclavable. General Purpose: Broad applications base. Chemical resistance- good for acids, alkalis, solvents, alcohols, oils, household cosmetics and aqueous products. Poor for hydrocarbon solvents. Liner provides tight seal.
Pulp / Poly-Vinyl
PTFE Faced Foamed Polyethylene (PTFE / PE Foam)
Polyethylene Cone (PE Cone)
Styrene-Butadiene Rubber (14B)
Styrene-Butadiene Rubber / 0.005 PTFE (PTFE / Styrene- Butadiene)
A one piece, three ply coextruded liner consisting of both foamed and solid LDPE. The foam core is sandwiched with solid clear PE.
Foamed Polyethylene (PE Foam)
PTFE Faced Silicone Rubber (PTFE / Silicone)
The liner consists of 0.005” thick PTFE bonded to 0.055” thick silicone rubber.
Ideal for low temperature storage applications. PTFE facing provides excellent chemical barrier. Autoclavable
Good barrier properties, good resistance to hydrocarbons, oils, ketones and alcohols. Not good for acids or alkalis.
Pulp / Metal Foil
Aluminum foil bonded to pulp board.
Low Density Polyethylene (LDPE) Disk
Manufactured from polyethylene.
Good for distilled water, analytical standards and reagents.
Note: Closures and liners are designed for a variety of applications. Product performance can vary depending on conditions. It is recommended that proper tests be performed to determine the best liner for the application. Torque for Screw Closures The integrity of the closure-to-container seal is dependent upon a number of variables, such as the materials of the closure, liner, and container, the sealing surface of the container, and the application torque applied to the closure. The most important of these is the application torque. If the closure is applied too loosely, the contents could leak, especially during shipping. If the closure is applied too tightly, it may be too difficult to remove, or the container could break during application. Table 2 offers some suggested torques that should provide an adequate seal for most applications. It is recommended that proper tests be performed to determine the optimum torque for the application. The most practical way to check the tightness is to measure the removal torque after the closure has been on the container for about 5 minutes. The removal torque should closely approximate the application torque. The minimum removal torque noted in the table should be maintained after a 24 hour period.
Table 2. Suggested Torques for Closures (in-lb)
Phenolic / Urea Closure
Phenolic / Urea Closure on Plastic Container
PP / PE Closure on Glass Container
PP / PE Closure
on Glass Container
on Plastic Container
Closure
Application
Min Removal
Application
Min Removal
Application
Min Removal
Application
Min Removal
mm
Torque
Torque
Torque
Torque
Torque
Torque
Torque
Torque
15 18 20 22 24 28 33 38 43 48 58 70 89
8 9
4 5 5 6 6 7 9
6 7 8 9
3 4 4 5 5 6 7 7 9
12 13 15 17 18 21 24 29 33 36 44 52 65 75
7 8 9
8 9
4 5 5 5 6 7 8 9
10 11 12 14 18 20 22 24 28 35 45 50
10 11 12 14 17 19 22 24 29 35 45 50
10 11 12 14 17 20 22 26 32 40 45
10 12 15 17 18 20 24 28 36 40
10 11 12 14 18 22 25
11 12 14 17 22
10 12 14 18
100 25 Although the information in this chart was acquired from reputable sources, it should only be used as a guide in determining the proper application torque. DWK Life Sciences accepts no responsibility for the accuracy of this data or for any consequences resulting from its use. 20
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