ISO 20127:2020 pdf download Dentistry — Physical properties of powered toothbrushes
6.4.2 Procedure Place the powered toothbrush in the gripping unit (6.4.1.1) and lock into place so that the clamp (6.4.1.2) pulls the tuft along the long axis of the tuft without any twisting. The brush head shall not be compressed during or after the placement. Place the clamp on the filament tuft. Be sure to clamp all of the filaments from one tuft only; do not include filaments from the surrounding tufts.
The filaments from one tuft should be secured at approximately the midpoint of the tuft length. Record the force required to pull out the tuft using the testing apparatus (6.4.1.3). Test two tufts of each tuft type (if available). The tufts should be non- adjacent. NOTE The different types of tuft are determined in view of properties such as filaments having different materials, length and diameters, or different shapes and diameters of the hole. 6.5 Brush head plate retention
6.5.1 Apparatus
6.5.1.1 Brush head holder, to hold the shaft of the brush head. This is a universal spring-loaded holder designed to accommodate a variety of different brush heads. The top vice is moveable and can slide back and forth on the brush head holder, and the bottom vice is locked onto a mounting base (6.5.1.2) with clamps (6.5.1.3). Swivel headgrips, adjusted with set screws, hold onto the shaft at different points and angles to accommodate different shaft designs. See Figure B.1. NOTE The brush head refers to the removable working end (i.e. refill) of the powered toothbrush.
6.5.1.2 Mounting base, to mount the brush head holder (6.5.1.1) to a mechanical test apparatus (6.5.1.5). See Figure B.2.
6.5.1.3 Clamps, to attach the brush head holder (6.5.1.1) to the mounting base (6.5.1.2).
6.5.1.4 Gripping unit, to securely grip the tuft plate of the brush head, without inducing forces in the tuft plate that would lead to significant deformation. Examples of appropriate gripping units are the following: a U-shaped fixture, with a collar large enough to grip behind the tuft plate (see Figure B.3); an embedding rod, which accommodates all circular tuft plate designs and secures the tufts of the brush head with dental resin material to minimize any compressive forces on the tuft plate (see Figure B.4).
6.5.1.5 Mechanical test apparatus for applying, measuring and indicating the brush head removal force, a digital force gauge or a universal testing machine with sufficient force capacity, an appropriate accuracy and a cross-head speed at least up to 50 mm/min. 6.5.2 Procedure Adjust the socket head screws on the brush head holder (6.5.1.1) to open the fixture and slide the brush head in between the top and bottom vice. When positioning the brush head between the top and bottom vice, leave only enough space between the brush head holder and the tuft plate for clearance of the gripping unit (6.5.1.4) to be attached to the tuft plate (see Figure B.5).
NOTE 1 Inter-laboratory testing has shown that the position of the brush head in the brush holder can have a significant effect on the measured head-retention force. With the brush head holder (6.5.1.1) placed on the flat surface of a table, adjust the setscrews on the swivel head grips for both the top and bottom vice of the brush head holder until the tuft plate of the brush head is parallel with the table surface. Attach the mounting base (6.5.1.2) to the base of the mechanical test apparatus (6.5.1.5).
Calibrate the mechanical test apparatus (6.5.1.5) with the gripping unit (6.5.1.4) attached to the moveable crosshead of the mechanical test apparatus. NOTE 2 This step is for a mechanical test apparatus that has software with the ability to perform calibrations with test fixtures, such as the gripping unit, attached to it. With the brush head mounted in the brush head holder (6.5.1.1), secure the gripping unit (6.5.1.4) on the tuft plate of the brush head.ISO 20127-2020