pph管的挤出成型工艺流程方法介绍

pph管的挤出成型工艺流程方法介绍

Introduction of extrusion process of PPH pipe

 

pph管的挤出成型工艺流程方法介绍

Introduction of extrusion process of PPH pipe

1、原料的选择：挤塑聚丙烯管材用树脂，其熔体流动速率在0.2～0.3g/10min范围内。一般熔体流动速率在0.2～0.4g/10min范围内的树脂应用较多。

1. Selection of raw materials: resin for extruded polypropylene pipe, its melt flow rate is in the range of 0.2-0.3g/10min. Generally, resins with melt flow rate in the range of 0.2-0.4g/10min are widely used.

2、聚丙烯管生产工艺顺序：与通用型聚乙烯管的生产工艺顺序相同，工艺顺序如下。原料开袋检查质量→挤出机把原料塑化熔融→模具成型管坯→真空定径套冷却定径→真空喷淋冷却→管材冷却降温→牵引→切割→检验质量→入库。

2. Production process sequence of polypropylene pipe: the same as that of general polyethylene pipe, and the process sequence is as follows. Open the bag and check the quality of raw materials → the extruder plasticizes and melts the raw materials → the mold is formed into the tube blank → the vacuum sizing sleeve is cooled and calibrated → the vacuum spray is cooled → the tube is cooled and cooled → the traction is pulled → the cutting is performed → the quality is inspected → the product is put into storage.

3、设备的选择：聚丙烯管材多采用通用型单螺杆挤出机生产成型。

3. Selection of equipment: polypropylene pipes are mostly produced and molded by general single screw extruder.

螺杆结构为等螺距不等深渐变型，长径比为(25～30)：1，压缩比为2.5～4。成型模具结构多为直通式，芯棒定型平直部分长L=(2～5)D(D为管材的直径，直径小时取***值，管材直径***时取小值)。定径套的内径d=D/(1-δ)(D为管材直径，δ为管材收缩率，一般δ=2.7%～4.7%)。

The structure of the screw is of constant pitch, unequal depth and gradual change, the ratio of length to diameter is (25-30): 1, and the compression ratio is 2.5-4. The structure of the forming die is mostly straight through type, the length of the flat part of the core bar is L = (2-5) d (D is the diameter of the pipe, the larger value is taken when the diameter is small, and the smaller value is taken when the pipe diameter is large). The inner diameter of the sizing sleeve is d = D / (1 - δ) (D is the pipe diameter, δ is the pipe shrinkage, generally δ = 2.7% - 4.7%).

4、管材挤出成型工艺温度：机筒的加料段150～165℃，塑化段170～180℃，均化段190～220℃。成型模具温度190～220℃。

4. Tube extrusion process temperature: feeding section 150-165 ℃, plasticizing section 170-180 ℃, homogenizing section 190-220 ℃. The mold temperature is 190-220 ℃.

5、PPH等塑料管材在生产过程有时会出现塑料化不***、焦烧，这是什么原因呢？

5. In the production process of PPH and other plastic pipes, poor plasticization and scorch sometimes occur. What's the reason?

一、焦烧

Coke burning

1、焦烧的现象

1. Scorch phenomenon

（1）温度反映超高，或者是控制温度的仪表失灵，造成塑料超高温而焦烧。

(1) the temperature reflects the ultra-high temperature, or the instrument controlling the temperature is out of order, causing the plastic to scorch due to the ultra-high temperature.

（2）机头的出胶口烟雾***，有强烈的刺激气味，另外还有噼啪声。

(2) there is a large smoke at the rubber outlet of the machine head, which has a strong pungent smell and crackling sound.

（3）塑料表面出现颗粒状焦烧物。

(3) granular scorched substance appears on the plastic surface.

（4）合胶缝处有连续气孔。

(4) there are continuous air holes at the joint.

2、产生焦烧的原因

2. Causes of scorch

（1）温度控制超高造成塑料焦烧。

(1) plastic scorch caused by over high temperature control.

（2）螺杆长期使用而没有清洗，焦烧物积存，随塑料挤出。

(2) if the screw is used for a long time without cleaning, the scorched material will be accumulated and extruded with the plastic.

（3）加温时间太长，塑料积存物长期加温，使塑料老化变质而焦烧。

(3) if the heating time is too long, the plastic deposit will be heated for a long time, so that the plastic will age and deteriorate and burn.

（4）停车时间过长，没有清洗机头和螺杆，造成塑料分解焦烧。

(4) the parking time is too long, the machine head and screw are not cleaned, resulting in the decomposition and burning of plastic.

（5）多次换模或换色，造成塑料分解焦烧。

(5) mold change or color change for many times, resulting in decomposition and burning of plastic.

（6）机头压盖没有压紧，塑料在里面老化分解。

(6) the head gland is not pressed tightly, and the plastic is aged and decomposed inside.

（7）控制温度的仪表失灵，造成超高温后焦烧。

(7) the temperature control instrument fails, resulting in scorch after ultra-high temperature.

3、排除焦烧的方法

3. Method of eliminating scorch

（1）经常的检查加温系统是否正常。

(1) regularly check whether the heating system is normal.

（2）定期地清洗螺杆或机头，要彻底清洗干净。

(2) clean the screw or head regularly and thoroughly.

（3）按工艺规定要求加温，加温时间不宜过长，如果加温系统有问题要及时找有关人员解决。

(3) according to the requirements of the process, the heating time should not be too long. If there is a problem in the heating system, it should be solved by relevant personnel in time.

（4）换模或换色要及时、干净，防止杂色或存胶焦烧。

(4) mould change or color change shall be timely and clean to prevent mottled or burnt glue.

（5）调整***模具后要把模套压盖压紧，防止进胶。

(5) after the mold is adjusted, the mold sleeve gland shall be pressed tightly to prevent the glue from entering.

（6）发现焦烧应立即清理机头和螺杆。

(6) clean the head and screw immediately in case of scorching.

二、塑化不***

II. Poor plasticization

1、塑化不***地现象

1. Poor plasticization

（1）塑料层表面有蛤蟆皮式地现象。

(1) there is toad like ground on the surface of plastic layer.

（2）温度控制较低，仪表指针反映温度低，实际测量温度也低。

(2) the temperature control is low, the temperature reflected by the instrument pointer is low, and the actual measured temperature is also low.

（3）塑料表面发乌，并有微小裂纹或没有塑化***地小颗粒。

(3) the plastic surface is black, and there are tiny cracks or small particles without good plasticization.

（4）塑料的合胶缝合的不***，有一条明显的痕迹。

(4) the gluing of the plastic is not well sewn and there is an obvious trace.

2、塑化不***产生的原因

2. Causes of poor plasticization

（1）温度控制过低或控制的不合适。

(1) the temperature control is too low or improper.

（2）塑料中有难塑化的树脂颗粒。

(2) there are resin particles that are difficult to be plasticized in plastics.

（3）操作方法不当，螺杆和牵引速度太快，塑料没有完全达到塑化。

(3) the operation method is improper, the screw and traction speed are too fast, and the plastic is not fully plasticized.

（4）造粒时塑料混合不均匀或塑料本身存在质量问题。

(4) uneven mixing of plastics or quality problems of plastics during granulation.