Get in touch

Home> News

Discussion on the foaming basis of polyurethane sponge assembly line

Time : 2022-07-18

According to the track of raw material movement: tank-filter-pump-pipe-steering pneumatic valve-mixing chamber-pouring

Storage tank: the size of the tank should be related to the foaming site, the tank is too big, too small, too thick, too thin will increase the adverse factors of foaming.

Filter screen: the number of mesh of the filter screen affects the supply pressure of the pump, thus affecting the stability of the flow.

Pump: the size of the pump is related to the foaming flow range and the diameter of the output pipe, and the output per turn is the main parameter of the gear pump.

Individual gear pumps with pressure regulating valves should be paid attention to.

The bigger the pump, the better.

At present, most of the plunger pumps of domestic low-pressure machines are nylon plungers, which need to be equipped with sheet metal filters.

If it is a metal plunger, silicone oil should be added to the water.

The round-trip distance of the four plungers is matched properly to maximize the flow.

Pipeline: must match the flow range and the size of the pump.

Pneumatic steering valve: that is, when moving, make the raw material into the mixing chamber or into the reflux tube.

The steering valve with powder component and TDI component is easy to die or not open properly, so we should pay attention to it.

Mixing chamber: its diameter and length are important parameters and also the basis for calculation.

Pouring: in accordance with the principle of uniformity and continuity.

The swing frequency, conveyor belt speed and foam initiation speed should be coordinated.

Overflow tank: the tank volume is 20-60 liters, and the tank volume determines the residence time of raw materials in the tank.

Settling plate: if the foaming bottom of the assembly line is a straight line and the conveyor belt is open, this is a curve at the top of the bubble, and in turn, the curve is placed on the bottom of the assembly line, and the upper part of the bubble is a straight line, which is the principle of the flat roof of the settling board. it's also the basis for the adjustment of the settlement plate.

The drop and length of the settling plate are the main parameters, which should be matched with the speed of the conveyor belt and the viscosity of the reaction system.

Stirring speed: related to foaming internal pressure, flow rate and formula reaction speed.

Usually 4000-5000 revolutions per minute.

Air: air increases, bubbles tend to become thinner, but when air increases to a certain amount, bubbles do not become finer and bean holes appear, so it should be accurately mastered, usually 50-150.

Foaming pressure: the increase of pressure will strengthen the shear force of stirring, eliminate the number of initial nucleation points and make the bubble cell thicker.

Usually 1.8-2.4 atmospheres.

TDI delay: that is, the time TDI vomits later to prevent heartburn.

Usually set 0.1-1 second.

Conveyor belt speed: related to starting speed and settling plate.

The swinging hair has strict requirements on the speed of the conveyor belt.

Step 1: determine the total flow.

Step 2: determine the diluted formula, assuming 1: 7 dilution of amine and 1: 5 dilution of tin.

Per kilogram.

Step 3: determine the amp value and scale value.

Step 4: measure the flow rate and correct the AMP value and scale value calculated by the formula.

Water, TDI, MC are glass rotor Flowmeter, the unit is the scale on the Flowmeter.

Polyether should be pressurized to measure the flow rate, silicone oil should add air to measure the flow rate, and small materials should be used to measure the flow rate at the head of the machine.

Discussion on the foaming basis of polyurethane sponge assembly line

email goToTop