(I) treatment of burnt rubber:
(1) slight degree of coke burning:
Put the rubber material into the mill to roll thin pass, the roll distance can be a little too much at the beginning, and then reduce the roll distance to 0.
5 ~ 1.
At the same time, add l ~ 3 portions of stearic acid.
At this time, the temperature of the roller should be controlled below 45℃, the filling capacity should be less than 1/2 of the normal mixing capacity, the operation process can be adopted by direct disc rolling, film does not need to be rolled, every 5 times thin pass is a stage, for slightly burnt rubber, thin pass through a stage or two or three stages.
Parked for 24 hours, can be mixed into the normal rubber material for use.
(2) for those with a slightly higher degree of coke burning:
At this time, there is a small amount of mature glue particles in the material, but the area is not large, the glue particles are small, the film can be rolled in the mill, the roller and roller distance and the same operation.
The plasticizer zinc-pentachlorothiophenol was added in the thin pass rolling for 5 minutes and then the softener was added.
Light or colored glue, can add a small amount of rosin or terpene resin;
Black glue can be mixed with pine tar.
Make the rubber material soften, add about 5 ~ l0 parts, make it mix evenly.
Po tong after the next slice.
This kind of rubber can be mixed into the normal use of the rubber, but the dosage should not be too much.
It is about 5 ~ 10 of normal glue.
(3) serious coke burning:
Synthetic gum such as nitrile gum.
It is hard and tough to produce nitrile rubber during rolling.
It is easy to burn when mixing.
In particular, more filling agent is even more.
At this time, coke can occur in the rubber material into the mill, as mentioned above, but not only add plasticizer pentachlorothiophenol zinc salt, but also to add activator 420.
Zinc pentachlorothiophenol is usually added in 2 parts and activator 420 about l parts.
The chemical name of activator 420 is 2, 2 dithiodibis (tert-butylated para-cresol), which is often used in the production of recycled rubber.
Add zinc pentachlorothiophenol for rolling for 2 ~ 3 minutes, then add activator 420 for rolling for 3 minutes, then thin through, add softener liquid gumalon resin, or pine tar.
Or dibutyl phthalate.
After the plastic solution, the softening of the burnt rubber can be mixed into the normal use of the production of rubber.
In order to ensure that does not affect the quality, the amount should not be too much, can generally join the above glue 5 or so.
(ii) prevent coking in the process of production process operation:
The following measures should be taken to prevent coking in production:
1. Raw materials to be accurately weighed, especially important is the amount of accelerator and vulcanization agent should be accurately weighed, do not scale failure or weighing error to identify various accelerators, do not make a mistake.
2. The sequence of dosing materials in mixing should be correct. Generally, the sequence of dosing materials in mixing is as follows:
Raw rubber zinc chloride, stearic acid, anti-aging agent, strengthening agent and oil softener alternately add a sulfur, a promoter and a rubber material under the tablet.
Do not roll at a higher temperature, the feeding sequence is reversed, the accelerator is added in the final stage, it is safer to do so.
3. When accelerators and vulcanizing agents are added, they should be added in multiple batches, and the amount of each batch should be small and evenly distributed.
Avoid concentration in local areas, resulting in charred
4. The temperature of roller or mixing chamber should be strictly controlled.
Strengthen cooling water circulation and accelerate cooling.
Use lower temperature deep well water to cool, better effect at the same time should be stored in a lower temperature of the glue, do not close to the central heating heat flow or direct exposure to the sun.
Just rolled the next piece of film, the temperature is higher, do not play a dense roll, in order to heat, the best is thin ventilation cooling.