The established norms of consumption of tissue in the product is essential value. The main factor determining the consumption of tissue, is the square patterns of the product. The square patterns of the products is not constant. It depends on the size, length of the item model and the value of allowances onseams. 

There are several ways to define the square patterns. 

1. Method of determining the area of patterns on photoelectric machine of the IL (Fig. 152).
2. The overlapping geometric shapes. When the space of patterns in this way each pattern is divided into a number of rectilinear figures measure their areas (geometric formulas) and summarize the obtained value.
3. A combined method, in which the main part patterns measure, entering into the mold or describing around it rectangle, and small curved areas measured by planimeter.
4. How to re-layout. According to this method, first, all patterns placed on paper or cardboard without taking into account the technical conditions of the layout patterns and get some square - Ѕр1, then from that square cut out details, and the remaining attacks do the second layout, and get the area of the attacks - SP2. Then from the second layout cut out the resulting attacks of them do, the third layout areaЅр3. Having the area of the three layouts, calculate the area of curves by the formula

There are many different ways of determining the area of patterns, but the best of them method of determining the area of the photoelectron patterns machine IL, and in the absence of machines in mass production is widely used combination method. 

After determination of the area of curves commence experimental layouts. Experimental perform layout using templates in 1:1 scale. 

Important the condition of the layout patterns is its economy, which is characterized by the magnitude of internal attacks. The magnitude of internal attacks To determine according to the formula

where the percentage of internal attacks; SP - the area of the layout patterns, cm2; I is the area of patterns, cm2. 

The value of internal attacks depends on many factors. The main ones are the following: 

-the number of sets of patterns of the product layout; 
-a combination of razmernosti in the layout; 
-width layouts (cloth); 
-the method of laying out the fabric; 
-the kind of surface; 
-specifications for the layout of patterns; 
model, configuration details; 
-rational placement of the patterns in the layout.

As a result of experimental work it was found that for all kinds of garments layout patterns into two setsmore economical than single. 

To establish rules make several experimental layouts. Prior to the execution of each experimental the layout should be designed prior norm on oblavka on area-based patterns and acceptable standards magically attacks, if they do not exceed the performance achieved in the factory. 

Preliminary rule for the layout is calculated by the formula

where So - osmeloski area, m2; I - the area of the patterns, m2; HV is the standard magically attacks, %. 

The norm in RM. But m is determined by dividing the value of area of layout, So the width of its scope, AO, ie,

For each layout, determine the number magically attacks. Norm on the layout with the lowest percentage of internal attacks (and thus with the least amount of tissue) is taken as the norm for oblavka. 

Fig. 153. Photographing the layout patterns of the parts of garments
 

This layout photographed (Fig. 153) or copy to install PKU-2, which gives a thumbnail of the layout, or make a sketch pantograph. 

Enterprises establish the following types of rules: the norm for oblavka But; the norm of decking NN; the weighted average technical the norm of NT. 

When nastilanie tissues there are the following losses: the ends of the flooring; at the joints of the paintings inside the flooring; from the slack fabrics and from all limit waste. 

Rate on the deck is calculated by the formula

where But - the length of osmeloski, m; L - losses normative of the length of the deck, m; - the number of cloths in the flooring; K - the number of actual joints of cloths in the flooring; 0,02 - full tissue loss on a single joint of paintings, M. 

If we compare the norm of decking with the actual consumption of tissue on the floor, you can establish how economically made flooring.

Technical rule reflects the weighted average performance and is calculated on the basis of the weighted average of the square patterns, the average interest internal attacks, obtained for the experimental layouts, and rate of losses of the fabric along the length, expressed in percent:

where NT - technical rate of fabrics m2; I.CP.RDT - weighted average the area of the curve m2 (to the nearest 0.001); the HRV.RDT - weighted average the actual percentage magically attacks (accurate to 0.1) based the specific weight of the surface tissue and single and combined layouts; P - permitted standard losses of the fabric length; for wool petievich tissue - 1 %; for the silk is 0.9 %; for cotton and linen is 0.7 %. 

For planning the number of tissues types products parent organizations established the stock the norm. Atstock rules enterprises consider applications for the required amount fabrics for the production program. Stock rate set by types of products like medium and periodically (two to three year) review.