- Country of manufactureUkraine
- Shaft materialMetal
- Plastic processedPolyvinylchloride
- шлифовка валковшлифовка валков
Nearby rolls calender always rotate in opposite directions (one clockwise, the other anti -clockwise). With the passage of the rubber composition between calender rolls they are subjected to slight sagging, so the cylindrical surface of the roll sheet of the rubber mixture exiting from the calender, it is somewhat thicker in the middle than at the edges. To sheet obtained uniform thickness, the rollers of the calender undergo during manufacture special grinding so that the diameter of the middle portion of the roll was a few tenths of a millimeter larger than the diameter of the roll at its edges.
Release rubberized cord uniform thickness over the whole width thereof is achieved by improving the design of calenders , polishing rolls to the outside of the mirror surface , camber rolls , ensuring uniform power calender rubber mixture and a uniform velocity cord coating.
When working
rolls calenders
wear. Worn rollers reface ily pereshlifovyvayutsya. At each resharpening with
the working surface
of the roll is removed
layer thickness
of 0.5 to 5 mm, and when re-shlifovke- layer 0.01 to 0.5 mm. When the roll diameter is reduced to
a certain limit
, it is out of use, or restored by welding.
Grinding and
camber of the rolls
are produced on
special machines
. Since at the same calender may execute
various operations
(
sheeting rubber
mixture and lining
promazka tissues rubber
mixture), the
establishment of accurate
crown sizes in the middle
of the working portion of
the roll is extremely difficult.
The rubber content
in the composition for the filaments is 90-92%. Bey's work on
the preparation of the mixture
and its treatment on the calender requires exceptional attention. Milling ingredients should be the most subtle sift very carefully. Particular attention
should be
exerted when
mixing rubber
with ingredientami- necessary to achieve
uniform distribution
of the accelerator and sulfur in the mixture. Adhesion to rubber accelerator distribution is difficult and leads to
inhomogeneity of the filaments
. This
behavior characteristic
accelerators during mixing with the rubber is not so dramatically affects in conventional
rubber
, but quite noticeable in
the production of thin
sheets of low-filled mixtures. Calendering plates produced on
pyativalkovom calender
with the rolls nice and fine grinding. To eliminate air bubbles, and compliance with the required thickness plate yarn large caliber should be duplicated.
Calendered sheets are
rolled on drums vulcanization using a lining cloth and vulcanized in boilers in the steam environment.
Camber. To
compensate for deflection of the rolls
and
receiving sheets
rubber mixture
of equal thickness
on
the entire
width of the sheet
in some
rolls of the calender
while polishing
the work surface
give little bulge (barrel) or concavity. The process of giving
the work of the
roll barrel and the concave shape is called the camber.
Camber rolls
made naf petsialnyx
grinders
. Size
camber rolls
-
the difference between the
diameters of the middle and at the ends of the roll - usually low and rarely exceeds 0.3 to 0.4 mm and 0.1 mm convex to concave rolls. Size
camber of the rolls
depends on the properties of the material being processed,
the type of operation
, operating mode.
To eliminate the harmful influence of the elastic of dish and receive sheets rubber composition of uniform thickness over the whole of their width, some of the rolls of the calender while polishing the work surface give little bulge - bochkoobraz-ness.
In
the course of work
rolls bend
,
the gap between
them increases toward the center, which is unacceptable in
obtaining thin films
. To
compensate for roll deflection
sometimes
used the installation
of rollers, often -
camber rolls
, crossing and kontrizgib rolls. Bombirovannye rolls used in calenders for processing materials with stringent tolerances for gage
sheet width
. The amount of camber is obgchsno 0,075- 0.15 mm. In
modern designs
, this method is combined with the
adjustment of the gap
by crossing or kontrizgiba.
High demands are made
to the
cleanliness
of the working surface
of the roll because
the product after
the calender is usually not processed, in addition to grinding rolls also polirztot.
Round grinding rolls - up to 1000 mm diameter and length of the working part of the barrel to 3500mm overall length of 5000mm for tsentrahdo.