Plastic Science - Recycled plastics

What is recycled plastic?

Recycled plastics refers to the plastic raw materials obtained after processing waste plastics through physical or chemical methods such as pretreatment, melting granulation, modification, and so on. It is the reuse of plastics. Recycled plastics, granulated plastics have a broad prospect, turning waste into treasure, and products (plastic particles) have a wide market. Only through the recycling of resources can we truly achieve environmental protection and energy saving. The biggest advantage of the recycled material is that the price is absolutely cheaper than the new material. According to different needs, it only needs to process certain attributes and can make corresponding products, so as not to let the loss of resources

Advantages of recycled plastics

1. Environmental protection advantages

The slogan of saving resources has slowly penetrated into people's hearts, so the awakening of recycled materials is inevitable, so that people through the recycling of resources, in order to truly achieve environmental protection and energy saving. Recycled plastics have great environmental advantages over conventional plastics

2. Under the ban, it fills the domestic blank

To prevent pollution from primary processing from further moving into China, the country has banned imports of 24 types of solid waste in four categories, including plastic waste, unsorted paper, textile waste and vanadium slag. The policy will come into effect by the end of 2017. In this way, the gap left by recycled materials for imported waste plastics will be replaced by other plastic materials. As a market hungry for profits, recycled plastics are a good choice if completely replaced by new plastics will bring excessive costs for enterprises. In addition, recycled plastics are not prohibited.

3, policy to promote recycled plastics

"Industrial Green Development Plan (2016-2020)" requirements, by 2020, domestic waste plastic recycling consumption to reach 23 million tons. We will accelerate the efficient use of renewable resources and the standardized development of industries. Focusing on waste plastics and other major renewable resources, we will accelerate the application of advanced and suitable recycling technologies and equipment. We will build a number of clusters of renewable resources industries, promote cross-regional collaborative utilization of renewable resources, establish a regional recycling and utilization system of renewable resources, and gradually standardize the industrial order.

4, recycled plastic itself strong

The biggest advantage of recycled materials is that the price is absolutely cheaper than the new materials, but also according to different needs, processing a certain attribute, can produce the corresponding products, so that it will not let the loss of resources. Coupled with the development and progress of technology, the current recycled plastics have a certain degree of elasticity, high strength and wear resistance, good insulation performance.

Six kinds of recycled plastics process flow

A. Low density polyethylene (LDPE) production process

1. Crushing process

The effect of crushing and washing with water is better. Because some good high pressure film if keep enough clean, do not need to add new material can be re-blown film. So pay attention to cleaning in the crushing process, when the crushing material flow to the sink after the best roll again, the purpose of further washing cleaning point.

2. Drying process.

Generally, it is to the dryer to dry the remaining water, if the conditions are dried, so as to save electricity, improve the quality, of course, we should pay attention to prevent the material in the sun drying secondary pollution.

3. Granulation process.

Particles produced by special extruders have two basic uses: reblowing film and injection molding.

4. Grilling process, usually cold water grilling.

This process must pay attention to the packaging label. One for blow molding, one for injection molding, to avoid confusion. In addition, the bag with blow molding must be lined with outer bag to avoid secondary pollution.

B. Process flow of recycled polypropylene (PP)

1. First of all, separate the colors of various materials, because the separation will be convenient for users, and the price can be high.

2. Pulverize and rinse with water, go to the dryer to dry the remaining water, and then dry the bag. Mix with a mixer and add color and additives.

3. Special plastic machine for car granulation, but the granulation temperature can not be too high, easy to brittle, so we must pay attention to the temperature.

4 Water cooled cutting, to standard 3X4mm, otherwise the appearance of the good material is not good, not standard.

C. Regenerative polyethylene terephthalate (PET) process

1. The first is the selection process:

All kinds of PET bottle tablets to be selected and classified. To remove the outer label, you must first peel it off.

2. Pulverizing process

In the crushing process with water rinse, remove all kinds of PET bottle pieces in the dirt.

3. Place the debris in a steam treatment unit and add soda flakes to remove greasy and other stubborn impurities.

4. Wash with clean water, shake off the remaining water and bag. Then it is dried in a vacuum oven.

5. Spray wire, set, stretch with hot water steam, set again.

D. ABS plastic process flow

1. Pick out the materials, and separate the colors of electroplating and spray painting.

2. Chemical treatment, deplating, paint, but deplating paint must be careful, because the chemical potion has a certain proportion, to use protective supplies and containers, otherwise it will cause injury and other events.

3. Cleaning tank to clean, and then to dry, color matching or put auxiliary materials, the purpose is to improve the quality.

4 special extruder to granulation, but must be put on the filter, but the filter according to the product requirements and put.

E. Process flow of recycled polycarbonate (PC)

1. First of all, the purchase of PC selection, color must be separated;

2. Cleaning various colors of PC, and disc lamp holder deplating process. It is then dried, sorted, and sent to extruder for production.

3. Some PC is yellow, can produce porcelain white, transparent still produce transparent; Colorants and material additives can be added to other colors.

4. Special extruder granulation, but PC itself is easy to age so can not be repeated, granulation must be careful, cut packaging.

F. Process flow of regenerating polyvinyl chloride (PVC) hard material

1. First select the process, separate the colors.

2. Go to the crusher to crush, but also crush with water. Remove the pollution and wash with water, and then dry in the sun to prevent secondary pollution.

3. Mix and mix on mixer. If it is white material and add coloring agent, according to the need to put auxiliaries.

4. Special PVC extruder for scraping, cooling bagging label factory.

How to tell whether recycled plastic is good or bad

1. Transparency

Transparency is an important index to measure the quality level of medium and high grade recycled materials, materials with transparency, quality is good;

2. Surface finish

The surface of high quality recycled materials is smooth and lubricated;

3. Color

The uniformity and consistency of color is an important index to measure the quality grade of colored recycled material particles (white. Milky, yellow, blue, black and other colors).

4. Smell

Light with a lighter, blow out after 3 seconds, smell the smoke, distinguish the difference between it and the new material;

5. Drawing

After the raw material is lit and extinguished, with iron objects quickly contact melt, and then quickly open, to see if the forming of the silk is uniform, is uniform is good material, DORA a few times, will overlap the silk, again open, see it has no elasticity, can not open again and constantly, not broken or open a distance after broken is good material;

6. Melt

It is not a good material if black smoke or melt drops rapidly in the process of combustion.

7, the density of particles

Poor plasticizing regeneration process will lead to loose particles;

8. Use your teeth

First to experience the strength of the new material, and then compare, if relatively soft, mixed with impurities;

9. Look at the incision section

Rough and lustrous section, poor material quality;

10. Floating water:

To have a submerged that is bad;

The application of recycled plastics

1. Build roads

Compared with conventional pure asphalt pavement, this kind of polymer modified asphalt pavement performance is better, and durable.

2. Food packaging containers

3. Wood plastic profiles

4. Red carpet parade

5. Sun glasses, computers and printers

6, used to manufacture machine parts, components

7, used to make water pipes, agricultural machinery, packaging bags, cement bags;

8. It can replace some wood products

9, can be used to manufacture a variety of plastic bags, buckets, POTS, toys and other plastic products

10, living utensils, etc