Production of gypsum acoustic plates

Contents

1. Introduction of ____________________________________________________

2. Process Part _________________________________________

2.1. Product characteristics and nomenclature ___________________________

2.2. Selection, justification and description of the production flow chart ________

2.3.The operating mode of the enterprise _________________________________________

2.4. Need for raw materials ______________________________

2.5. Calculation of the main process equipment ____________________

2.6. Calculation of silos ________________________________________________

3. Production and quality control of finished products _______________________

4. Safety precautions _______________________________________________

List of literature ___________________________________________

Introduction

In today's world, the human body is exposed to various harmful factors, among them poor ecology, constant stresses, man-made factors. The harmful effects of noise can also be attributed to these problems. Noise is a chaotic, uncomplicated mixture of sounds that negatively affects the nervous system. The device for measuring noise level (noise meter) uses a special scale "A" with units of measurement "decibels A" (dBA). In the speech range, they almost coincide with ordinary decibels.

The human body reacts differently to noise of different levels and frequency composition. In the range of 3560 dBA, the reaction is individual (by the type of "interfering"). Noise levels of 7090 dBA with prolonged exposure lead to a disease of the nervous system, more than 100 dBA - to a decrease in hearing acuity of varying severity, up to the development of complete deafness. Noise discomfort in the room creates, first of all, the wrong choice of materials, which can create the so-called "sound porridge." The second reason is the poor shape of the room. For example, in rectangular "bottles" a "standing wave" often occurs - in some places the sound intensifies, and in some, on the contrary, weakens. Other undesirable sound effects may occur. For example, the phenomena of "flashing echo" (appears between two parallel walls) and "sound bounce" (reflection of sound from two or three surfaces converging in the corner).

To eliminate these undesirable effects, various acoustic materials are used in the decoration of rooms.

Sound-absorbing materials have a fibrous, granular or cellular structure and are divided into groups according to the degree of rigidity: soft, semi-rigid, solid.

Soft sound absorbing materials are made on the basis of mineral wool or fiberglass. These include mats or rolls with a bulk weight of up to 70 kg/m3 and a sound absorption coefficient of 0.7 to 0.95. The same group includes such long-used sound absorbers as cotton wool, felt, etc.

Semi-rigid materials include mineral wool or fiberglass boards with a bulk weight from 80 to 130 kg/m3 and a sound absorption coefficient of the order of 0.50.75. The same group includes sound absorbing materials having cellular structure - polyurethane foam, polystyrene foam, etc.

Solid materials have a volume mass of 300400 kg/m3 and a sound absorption coefficient of the order of 0.5. Produced on the basis of granulated or suspended mineral wool. The same group includes materials containing porous aggregates - expanded pearlite, vermiculite, pumice [2].

Let's analyze the main acoustic materials that exist on the market.

"Sound-teploisole"

This sound insulator is most effective for the floating floor soundproofing design. The material also has heat and hydro-insulating properties, which allows it to be used as a multifunctional gasket in the construction structures of intermediate floors of residential buildings, public and industrial buildings and structures.

The sound absorption effect of the Zvukoteploisol material is achieved through the use of a sound-absorbing multilayer elastic glass fiber (glassblower), which is made of the thinnest glass fiber. The material is multilayer and consists of the following layers:

Base (sound absorbing) - one or more layers of dense glass fiber (glassblower);

Protective bearing layer - polymer-bitumen structurally modified mixture. To give bitumen the necessary properties, the APP modifier (atactic polypropylene) is used, while bitumen polymerizes - it becomes strong, heat-resistant and durable;

Protective layer - additional protective polyethylene film.

When "Zvukoteploisol" is used, the value of reduced level of impact noise is 23 dB.

Mineral wool plates Akmigran

Akmigran mineral wool boards are sound absorbers made from granular mineral wool with starch binder by molding and subsequent drying of articles. It is strict compliance with production technology that guarantees the necessary acoustic parameters.

The sizes of plates Akmigran - 600х600х20 mm. Their average density is 350-400 kg/m3, the sound absorption coefficient is 0.7-0.9. Plates have low hygroscopicity and are non-combustible material .

Acminit type sound absorbers

Acoustic mineral wool plates Akminit are similar in manufacturing technology and properties to Akmigran plates. Unlike the latter, the forming of the Acminite boards is carried out from a mixture with a higher humidity, which reaches 400% (half-wet method), by compacting it on a belt conveyor with pressing rollers, with squeezing out a certain amount of water.

After drying the plates are facturized in different ways. To provide rough surface of plate, abrasive materials are treated, holes are drilled, teeth with blunted faces are pressed into surface of plates, which leads to formation of cracks, etc.

The semi-wet method of making boards is somewhat more complicated in terms of controlling the forming process than semi-dry, but at the same time has a number of advantages. Products are obtained with slightly higher strength (Rizg up to 1.5 MPa). Lower binder consumption, shorter drying time, products less susceptible to warping. You can get invoices that are more effective in acoustics and more expressive in decorative terms.

Selection, justification and description of the production flow chart

Production of perforated gypsum acoustic plates consists of the following stages:

- Preparation of raw materials

- Gypsum mass preparation

- Forming a continuous strip of a given section

-Perforation of sheet

- Cutting of strip into plates of specified size

- Drying of articles

-Packaging

Preparation of raw materials

In the manufacture of boards, cardboard serves as reinforcement for the gypsum core, betraying its strength and flexibility. For the manufacture of boards, special lining board is used. Cardboard comes in rolls with trimmed edges. Prepared rolls (without significant dents and damages) are installed on the unwinding unit. The paperboard rolls are unwound and pass through a tensioner in which the paperboard is brought to a tensioned position in the longitudinal direction .

Preparation of gypsum mass consists in the following: gypsum is closed with water with water-gypsum ratio B/G = 0.48 in mixer. Continuous flat strip with section of specified shape is formed on conveyor. From the unwinder, a lower web (double-layer with aluminum foil) and an upper web of cardboard are fed to the conveyor. A gypsum mixture is laid between the webs. The upper layer of the adhesive machine lubricates with PVA glue, and at the lower layer the edges are filled. Both layers are then rolled and a gypsum core web is obtained. As the web moves along the belt conveyor, the gypsum core solidifies to the density required for cutting and perforating operations.

The web is then fed to an accelerated roller belt. It is perforated and cut into sheets of specified dimensions by means of guillotine. The upper surface is then coated with an emulsion. The sliced plates are removed by the transition conveyor and transferred to the cantilever dispenser conveyor.

The dispenser distributes the plates to the dryer conveyors. The speed of the plate in the dryer is reduced. The slabs there are located in the drying chamber for about 1 hours (depending on the hardening time of the gypsum).

When leaving the dryer, the sheets go alternately to one roller conveyor. On it, the ends of the sheets are trimmed. The sheets are placed on a table where they are stacked and packed .

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