Figure 24. Measurement methods compression properties of products

The main methods of measurement (figure 24). compression characteristics of the products are: axial compression (a), axial stretching (b), unilateral, volume compression (in) and bilateral volume compression.

A device for measuring the compression of the product characteristics (figure 25). The device is intended for determining the deformation characteristics of products under axial compression.

The device consists of a body (1), consisting of upper and lower parts. Inside the upper part there is a sliding table (2), which is in a fixed position on the prisms strain Balka (3)attached to it by the load cells (4). On strain beam in the middle and is rigidly fixed boss to install and secure the base plate (5). Top and bottom plate (5) may be made from the same or different material. Mobile bar-nut (6) receives the reciprocating motion of the screw (7)rigidly connected with the electric motor (9) through the gearbox and speed variator allowing you to create different speed of motion of a rod nut. In the lower part of the rod nut fixed plate-a cross-beam (10), serving as a support for legs indicator, and upper working plate (5). The case of the device is installed the switch and the switch to the reverse. The device is equipped with a set of round plates of different diameter area of 5, 7, 10, 15 cm2.

Along with the shift of volume or axial compression and axial stretching are the main types of mechanical deformation of the product being processed and packaged. The main methods of measuring the axial tension-compression shown in Fig. 2.13.

Fig. 2.13. A schematic diagram of measuring devices compression characteristics:

a) axial compression: 1 - plate; 2 - the product; b) unilateral volume compression;

c) bilateral volumetric compression: 1 - the piston; 2 - product; 3 - cylinder;

g) axial extension: 1 - terminals; 2 – product

Measurement procedure are practically the same for all devices. Constructive schemes vary in the way of the drive plate: top and bottom, motor or directly from cargo.

The device is used for delivery of materials to the elongation (Fig. 2.14) consists of bath 1, which is poured a solution 2. The ends floating on the surface of the sample 4 fix in terminals 3, one of which is fixed. The measurement unit is a line 9, mounted on the rail. The loading mechanism consists of a shaft 7, cargo 11, yarn 10 tracks 5 and 8, brackets 6. The concentration of salt or sugar solution is chosen so that the sample (for example, dough) freely floated on the surface. The device is intended for research purposes.

Devices for measurement of deformation in compression are used to determine the elasto-plastic properties.

The device B.A. and A.S. Nikolaev Spiegelglas for deformation measurements uniaxial compression between parallel planes (Fig. 2.15) consists of the frame 1, which moves leg of a table. Tested material is placed between parallel planes drives 2 and 3. Top of them can move under the action of cargo 4, at the same time, it is connected with rail 8, meshing with the pinion gear 7, on the axis of which is attached arrow 6, showing the strain on a scale of 5. The lower disk 2 has the ability to move in the vertical plane with the help of an eccentric 9. On the described device, you can determine instant elastic deformation module, elastic compression as well as the viscosity and the ultimate shear stress.

Date: 2015-12-24; view: 820