How to calculate purchase weight based on length. The most basic formula is: mass = density × volume

  Volume = length × width × thickness (height)

  Converted, mass = density × length × width × thickness (height)

  According to the calculation, the density of PET is 1.4. According to the width and thickness of the customer's needs, the approximate weight can be calculated, which provides an important basis for the company to purchase the original film stocking.

  There is also a variant of this formula, length=mass/(density×width×thickness). According to this formula, it can be roughly calculated how many release films can be made from a certain wide  original film in the warehouse.

  Thickness conversion

  The commonly used units in the market are as follows: 1mm=100c (silk)=1000um. Among them, the unit c (silk) is not a national standard unit, and is more common in the hardware machinery industry. There are also individual companies that use "articles" as the unit, 1 article = 1c.

  The commonly used thickness of PET film has the following specifications: 0.012mm, 0.025mm, 0.036mm, 0.05mm, 0.075mm, 0.1mm, 0.125mm, 0.15mm, 0.175mm, 0.188mm, 0.25mm. The thickness of the PET release film is actually divided according to the thickness of the PET film.

  When you consult, you must clarify your own needs. Some companies are used to using mm, some companies are used to using c, and some companies are using microns. The most common mistake is to order 0.025mm wrong, 0.025mm=2.5c=25um, 0.25mm=25c=250um. I believe that many companies have encountered this situation, the demand is 25 thickness, and then the samples received are far from their own needs. This is caused by unclear unit differences.

  According to different substrates, it can be divided into: PE release film, PET release film, OPP release film and composite release film.

  According to the release force, it can be divided into: light release film below 6g, 20g lower release film, 20g upper heavy release film, and 100g super heavy release film.

  Release film peeling force distinction

  Usually 0.15N/25mm, that is, the peeling force of about 15 grams, commonly known as light peeling;

  0.250N/25mm, that is, the peeling force of 20-30 grams, commonly known as medium peeling;

  0.4~0.6N/25mm, that is, the peeling force of 40-60 grams, commonly known as heavy peeling;

  0.03~0.05N/25mm, that is, the peeling force of 3~5 grams, commonly known as ultra-light peeling;

  1.00N/25mm, that is, the peeling force of more than 100 grams, commonly known as overweight peeling.

  According to the color, it can be divided into: red release film, yellow release film, green release film, blue release film and other PET release films of various colors.

  According to surface treatment, it can be divided into: single-sided release film, silicon-free release film, fluoroplastic release film, frosted release film, matte release film, etc.