Cap Torque Tester

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Cap Torque Tester

Cap Torque Tester

Consistency in the cap torque applied to container caps employed in both the pharmaceutical and cosmetic industries is absolutely essential.


Consistency in the cap torque applied to container caps employed in both the pharmaceutical and cosmetic industries is absolutely essential.

If the cap is under-tightened, then the product may be exposed to atmosphere which could effect the stability or sterility of the product concerned and hence its overall efficacy. Over-tightening, on the other hand, may simply mean that the patient cannot access the preparation.

The R & D Department must decide, early in the life of the product, the form of packaging to be employed.

Torque Testing Systems provide an accurate and consistent means of applying and removing caps, in some cases, without any need for manual intervention.

The ensuing results can then be used to calculate, for example, application vs removal torques and removal torque over time (relaxation) and hence to optimise container/cap compatibility and permeation.

It is then the responsibility of Quality Control to ensure in-coming container supplies meet the agreed standard and both Production and Quality Control to ensure that the specifications relating to torque are adhered to during packaging prior to release to the end-user.

The CapStar is a bottle top torque tester designed to measure the tightening/release torque on a wide range of bottle closures. It has been developed in response to an increasing demand from within the cosmetic and pharmaceutical industries for a low cost, versatile and easy to use instrument.

Traditionally, the bottling and pharmaceutical industries have carried out the measurement of tightening and release torque by using mechanical spring loaded torque testers. These can vary in accuracy and provide no means of recording the results taken.

CapStar is a simple and easy to use digital torque tester. The containers to be tested are located in an adjustable jig capable of clamping circular or customised bottles and jars from 10 to 130 mm in diameter.

Child resistant closures, much used in the pharmaceutical industry, can also be accurately tested. The LCD digital read-out clearly displays the peak torque of each test.

The preferred unit of measurement may be sjelected from a list of seven options during initial set-up, namely Newton metres (Nm), Newton centimetres (Ncm), Kilogram metres (kgm), Kilogram centimetres (kgcm), Foot pounds (ftlbs), Inch pounds (inlbs) and Ounce inches (ozin).

Statistical analysis of sigma, mean and range is also available. A threshold setting can be specified to suppress spurious low readings when the cap is first gripped in the peak mode. This is the value of torque at which the display will begin to register torque readings i.e., exceeding this threshold signals the start of a new cycle. This is also a useful facility when a stiff cap takes several turns before it is opened.

Two modes of operation are available:

  • Peak Measurement:
    This displays the highest torque measured during tightening or releasing a closure and holds the displayed value until reset.
  • Track Measurement
    This displays the torque that is being applied at any instant. The read-out will return to zero once the grip has been relaxed.

The CapStar has a maximum capacity of 4 Nm (overload capacity 125% Full Scale Deflection = 5Nm). Accuracy of the Transducer is /- 1% FS, that of the display is /- 1 LSD.

Note: 2 and 6 Nm Versions available to special order.
CapStar is housed in a rugged, drip-proof ABS Plastic Housing with wipe-clean, touch sensitive controls. It measures 122 x 120 x 113 cm and weighs approximately 3.5 kilos.

Battery power means that the unit is completely portable. The screen displays a warning when the batteries need replacing or charging. To save power, CapStar is fitted with an automatic shut-down if no key is pressed for a specific period (the period concerned is user adjustable at time-out values of either 1, 2, 5 or 10 minutes).

Alternatively, the unit can operate from mains power using the charger unit provided for this purpose.
CapStar has a memory capacity of over 200 readings. In addition, the unit is provided with a RS 232 Serial Output as standard. This allows torque data to be downloaded to a printer for hard copy storage or to a PC for data collection.

All units supplied are issued with a calibration certificate traceable to National and International Standards. All setup features are programmable directly from the keyboard and are retained even when the unit is switched off.

A summary of the main features of CapStar are listed below:

  • Low cost
  • Battery or mains power
  • Adjustable bottle rig
  • Easy to read digital display
  • RS232 printer connection as standard
  • Rugged, portable, drip-proof
  • Peak or track measurement options


Call us on 051 392 391 with your instrument problems and we will recommend a solution - advice is FREE!