UTOP SPC Flooring Processing technology

1. Recipe and weighing

For materials with different weights, it is necessary to use weighing instruments with corresponding accuracy to ensure weighing accuracy.

Integration of materials: It is convenient to store weighing and transfer materials, and it is necessary to carry out sampling and review of components and accuracy. If it is an automatic weighing system, monitoring and review are also required.

2. Mixture storage

Order of feeding: Determine the order of feeding according to the way of feeding.

The automatic feeding and mixing system can be set up as follows: filler ↑ 90 ℃, treatment agent and PVC resin ↑ 95 ℃, stabilizer lubricant ↑ 105-110 ℃, processing aid enhancer ↑ 115 ℃, return material ↑ 120-125 ℃.

Manual feeding: PVC resin + filling material + small material + PVC resin + filling material + PVC resin + return material; one-time feeding, 120-125 ℃ discharge.

Cold mixing: must be fully and quickly cooled to prevent the material from deteriorating, and has the ability to cool to 40-45 ℃.

Storage: In order to ensure the uniformity of the material, it is necessary to use a large storage tank to store and put it aside for a certain period of time before use.

To mix materials that have been put on hold for a certain period of time, it is necessary to detect the dry flow of different batches of materials and the rheological properties of the logistics, as a monitoring method, and provide a basis for analysis and improvement.

Note that there are differences in mixing effect between different mixers, and differences in mixing temperature and time.

3. Extrusion process

The setting of processing technology not only affects the processing level, but also affects product quality and production efficiency. It needs to be comprehensively considered in combination with equipment characteristics, material properties and formulations.

The relationship between the size of the extruder and the product specifications:

The size of the extruder has a certain relationship with the cross-sectional size of the product.

For example, the 110 extruder is difficult to make a 4mm thick plate. First of all, at a certain extrusion speed of the large extruder, the production line speed is already very fast, and the molding pressure is relatively high. The plasticization and fluidity requirements of the material are high. If the gap is produced by opening a large die, the longitudinal stretch is relatively large. The requirements for melt strength are high, and due to the tensile orientation, it is easy to cause a large difference between the longitudinal and longitudinal shrinkage rates, causing excessive shrinkage and warpage of the sheet. At the same time, high-speed production also has high requirements for calendering and cooling.

If the 110-extrusion production line is used to produce flooring, the formulation process should be carefully designed and set up.

According to the current situation: 92 and 80 units are more suitable for the floor under 4mm. The die gap is slightly larger than the floor thickness.

Body: The temperature in zone 1 and zone 2 is very important. It is necessary to ensure that the plasticization is easy to evacuate. Too high, easy to accumulate material in the vacuum port, generally between 185-195, other can be slightly lower.

The temperature of the confluence core has a great influence on the back pressure. A lower temperature is beneficial for the melt to change from spiral movement to linear movement, generally at 165-175 ° C.

The temperature of the mold is relatively higher, which is conducive to the flow of melt with small gaps. Generally, it is between 190-200 ° C, and the thickness of the blank is adjusted uniformly according to the mold gap.

Extruder main engine speed: generally controlled at 75-85% of rated speed. The feeding speed is mainly determined by the rotation speed of the host and the current of the host (load).

Under the premise that the formula is determined, the processing temperature, the rotation speed of the host machine and the feeding speed match each other, so that the current is stable, the discharge is uniform, the surface is free of defects, and there is a certain production speed.

The screw will wear during a certain period of time. First, the processing technology can be adjusted, such as reducing the extrusion speed, increasing the feeding speed, and appropriately increasing the processing temperature of the first and second zones to reduce the temperature of the confluent core. Properly adjust the formula to increase the amount of ACR. If necessary, readjust the clearance of the screw barrel, polish and polish the damaged parts, and then adjust the process formula.

4. Calendering process

Under the premise of stable extrusion.

Main control: matching of roller gap, temperature, speed, and front and back speed.

The gap and speed of the first pair of rollers determine the basic thickness of the floor, which should be preliminarily determined according to the linear speed of extrusion. The speed of the roller behind the film is slightly faster to ensure that there is a certain expansion force, which does not cause the film to narrow. This is true for the traction speed, so that the sheet does not deform. Some adjustments are slower according to the actual situation. Embossing and filming are mainly determined by the roller gap and roller temperature. Different sheet thicknesses and film types use different gaps and temperatures, and consider the effect of traction speed.

Roller gentle speed: It should be ensured that the calendering is normal, the embossing is clear, the film is firmly bonded, the trimming is sufficient, and the film is not deformed.

Roller temperature: generally 165-185 ℃.

The gap between the two pairs of rollers is basically the same. The two need to be adjusted together.

Reference production process of 80mm 4mm floor reference:

Hot mixing: 125 ℃ Cold mixing: ≦ 45 ℃

Die gap: slightly smaller in the middle of 3.8 ～ 4.0

Body:

Zone 1          Zone 2         Zone 3             Zone 4           Zone 5         Confluence Core

190               185               180                   175                180               165

Mould one   Mould two   Mould three    Mould four    Mould five    Side plate

192                191               190                 191                 192               195

Host speed: 20rpm host current; 75A

Feeding speed: 10rpm

Rolling gap: 4mm

Roller temperature: 175 ℃

Roller and traction speed: 600 (table value)

5. Stereotypes and others

Because the products in the production process have not been completely finalized, the cutting flow is to avoid stress, and the loaded tray needs to be firm and flat. Product testing also requires the base material and finished product to be sampled for a certain period of time.