Polystyrene foam agent is made of polystyrene resin as the main body, adding foaming agent and other additives, which is currently used as a buffer material. Polystyrene foam in China production mainly concentrated in the Northeast China, Jiangsu and Zhejiang and Beijing, Tianjin, Hebei, and which to small and medium enterprises for more.
2007, 2008, 2010, 2011 and 2012 respectively five adiabatic moulded polystyrene foam board for the national supervision and spot checks, the product qualified rate of 95.1%, 96.3%, 97.5%, 97.5% and 97.8%, respectively. Product quality is stable, but there are still some problems. The main problems are in the apparent density, oxygen index, combustion classification, etc.. Spot checks found that Hongshan Xingda District Wuhan heat preservation material factory a batch of product apparent density project is not qualified.
When the polystyrene foam board density is insufficient, if used for building exterior wall external insulation will lead to the tensile strength is low, can not meet the insulation system weight and finishes loading on the shear strength of bearing requirements, easy to make in the middle of the EPS board is pulled off. At the same time, EPS board density problems will lead to lowering thermal insulation, moisture absorption increased, affecting the construction of heat preservation effect, polystyrene foam board will not building energy-saving insulation.
At present, China's EPS production enterprises of about 2000, polystyrene foam plastic production momentum is good, the quality continues to improve. But the number of large enterprises is small. It is reported that the apparent density is the unit volume of the foam in the specified temperature and relative humidity conditions of the quality. Apparent density, to some extent, affects the other physical performance indexes, and the cost of the product directly.On the other hand, polyethylene foam recycling and styrofoam recycling is necessary.
China's thermal insulation materials market started late, especially the development of the organic class of insulation materials market is lagging behind. In the past ten years, the state actively promotes the development of energy-efficient construction, reduce energy consumption, the external expansion polyphenyl plate thin plastering exterior wall insulation technology has been widely used, polystyrene foam blowing agent demand will continue to increase, driven by the rapid development of EPS production enterprises.
In exterior wall thermal insulation material fire are mainly two factors: ignition source is external factors, construction process, improve construction standards, can reduce the chance of fire; polystyrene foam insulation pipe shell and extruded polystyrene foam with this two kinds of combustible materials is the internal factors. In order to prevent the occurrence of fire, only the use of non combustible or difficult to burn the external wall insulation material, which is the most effective solution strategy.
Polystyrene foam insulation pipe fire is one of the key works in the construction process, must strengthen the operation of the workers. Usually case, the outer layers of the insulation materials the reason why the phenomenon of fire, due to a specific method for to fire workers accidental errors or irregularities caused by, many different suggestions and strategies. At present, the widespread use of exterior wall thermal insulation material is made of polystyrene foam and extruded polystyrene foam, the two materials are combustible can say, there is a corresponding fire hazard.
In the construction process, can not completely prevent the fire, for example, the process of the welding process of the spark, therefore, the construction site, there is a source of fire. Because of the fire and the fire of the two factors, can not be prohibited. Therefore, the external wall insulation material caused by the fire, in fact, is the inevitable.
Now our country's building uses the external wall exterior insulation material mainly includes two kinds: one is the polystyrene foam. The two is extruded polystyrene foam. These two kinds of data are widely used, because they have insulation, waterproof and gas well. However, through some tests found if the two no after the flame retardant chemical molecular modification, but only a local flame retardant is added in the data, once the polystyrene foam insulation pipe encountered fire, can easily lead to burn it, and in the process of combustion to generate corresponding toxic gases, influence people's life safety.
In addition, under the condition of high temperature, polystyrene foam and extruded polystyrene foam easily lead to crashing phenomenon. That is to say, has triggered a fire hazard.
The advantages of Polystyrene foam insulation board
Polystyrene foam insulation board, foam board, also known as EPS board, mainly used in building facades, cold storage, air conditioning, vehicles, ships of the insulation system, more extensive use, then the polystyrene foam insulation board what
1 light. China's standard provisions of the bulk density of EPS 18~22kg/m3 board, the European EPS 15kg/m3 board only;
2 low thermal conductivity. Because of its air filled with air structure, to prevent the spread of air, so that its thermal conductivity in 0.039;
3 because of the space in the 98% of the board is filled with air, there is enough capacity to buffer the impact force by changing the shape of the external impact, the impact of good;
4 low water absorption. Studies have shown that humidity can affect the thermal performance and mechanical properties of materials, and the low water absorption of the material will help to maintain these properties;
5 can be recycled. The recovery is the highest in the plastic;
Do not apply in the production process of freon 6;
7 the energy consumption of the whole life cycle is the lowest in the plastic products.
Plastic is used in our life in the face, such as food packaging, cups, water bottles, cosmetic bottles, and so on and so forth. We can see how large the amount of waste plastic is produced every day. First of all the waste plastic recycling to be cleaned, melting, drawing, granulation and other processes to become recycled plastic particles. Recycled plastic particles to be used again in accordance with the level to make a variety of products again into our lives. Plastic has a wide range of applications, the use of large, therefore, recycled plastic particles have a huge market potential and value. However, recycling of waste plastics is not an easy thing. First of all, the policy of the current recycling of waste plastics in China is mainly rely on "picking up a bottle of army" and other folk channels to complete the recycling of waste plastics. But close paragraph of time, the impact of oil prices, to recycle plastic bottles almost unprofitable, picking up the enthusiasm of the bottle army without, the recycling of plastic bottles have great influence.
This shows that the government should establish official recycling channels, so that the market can not drive the recovery of waste plastics can be used to ensure that the normal flow of waste into the factory to recycle. From the policy side, should support the regular plastic recycling enterprises, improve the recycling mechanism and standards, so that recycling of waste plastics has a clear quantitative criteria. Next is the technology of our country polyethylene foamrecycling method is mainly for the physical regeneration, recycling of waste plastics by classification, cleaning, granulation directly processing. There are a lot of ways of recycling waste plastics, in addition to physical recovery also includes energy recovery, chemical reduction and used as solid fuel. China's waste plastics processing and utilization technology is relatively low, a lot of waste plastics processing enterprises do not have the strength to introduce foreign advanced technology, but also unable to develop new technology and new technology. Finally is a waste of a variety of plastic recycling a single said waste plastics we first thought is beverage bottles or other large volume of plastic products, pet plastic bottle is occupied the absolute share of plastic bottle packaging market. But there are several kinds of waste plastics often overlooked by people, such as PE plastic bottles, acrylic, these waste plastics also has great economic value. Waste plastics recycling, or other waste recycling is in fact a global problem, but the current foreign technology or recycling system is more advanced than the domestic. China should actively introduce foreign advanced processing technology, more important is learning foreign waste recycling system, draw lessons from the advanced experience, to increase recovery and utilization of waste plastics and let the waste plastic recycling the long-standing problem is no longer difficult.
At present, plastic machinery has obvious change: the process is more complex and highly automated equipment. Therefore, the requirements of the mathematical model of the process and the consistency with the actual conditions of the polymer processing are improved.On the other hand, polyethylene foam recycling and EPS recycling is necessary.
In the production process of membrane tube, those for preparation of melt the traditional machine structure, such as screw extruder are essentially changes (the first is the working surface of the screw geometry and barrel), using the new filter, head and film heat treatment and a traction device etc. structure. The process and equipment of the production line can improve the productivity of the production line 0.5 - 1 times, and the film thickness is decreased by 50%.
At present, the combination principle is widely used in the construction of equipment, that is, each of the main bodies in the process can achieve the maximum possible function independently. This not only can be used to improve the uniformity of the equipment, but also in time and quickly so that the production line of local modernization, and created an alternative to the favorable conditions for the device and mechanism. For example, the shearing and mixing elements of multi section screw, and a belt groove barrel, improving extrusion machine productivity 0.5 - 1.0 times, and maintain necessary melt temperature and improve its uniformity (heterogeneity). Also, the modern problem of forming machine head, filter, traction device and coiling device is also solved. In this case, such as controlled motor drive system, heating and automation system, the cover and the structure of the components (elevated, press machine, etc.) and other equipment unit practically does not change.
Depending on the green to select the appropriate packaging material, containers, forms and methods to meet the basic requirements for food packaging.
Volume and quality of the packaging should be limited to the lowest level, the implementation of reduction package.
In the technical conditions permit, consistent with the relevant provisions of the commodity situation, should choose reusable packaging; if not reusable, recyclable packaging materials should be; if it can not be recycled, the packaging waste to be biodegradable.
Paper Packaging Requirements:
- Reusable recycled or biodegradable;
- The surface does not allow wax, oil;
- Do not allow moisture-proof coating plastics and other materials;
- Carton connected adhesively to be taken, not allowed to use flat wire stapled;
- Made to mark the cartons with water-soluble ink must not allow oil-soluble ink.
Metal packaging should be reused or recycled, should not be used to cause harm to humans and the environment and a paint sealant.
Glass should be reused or recycled and EPS recycling is necessary.
Plastic products require:
- Use of packaging material should be reused, recycled or biodegradable.
- While protecting the contents intact, try to use a single material material.
- Use of PVC products, their monomer content should be consistent with GB9681 requirements.
- Use of polystyrene resin or molded product shall comply with the national standards.
- Do not allow the use of expanded polystyrene (EPS) chlorofluorocarbons (CFS) and polyurethane (PUR) and other products.
Printing ink mark on the packaging or labeling of the adhesive should be non-toxic and should not be in direct contact with food.
Reusable or recyclable packaging, waste disposal and use of its execution according to the provisions of GB / T16716 in.