Properties of EPS

EPS has been a material of choice for over 40 years because of its technical versatility, performance and cost effectiveness. It is widely used in many everyday applications where its light weight, strength, durability, thermal insulation and shock absorption characteristics provide economic, high performance products.
(1) Light Weight
EPS is an extremely lightweight material which is not surprising considering it is comprised of ~95% air. This characteristic makes it ideal for use in packaging as it does not significantly add to the weight of the total product thereby reducing transportation costs. Energy consumption for transport fuel is also reduced and vehicle emissions minimised – all contributing to lower global warming.
(2) Durability
The exceptional durability of EPS makes it an effective and reliable protective packaging for a wide range of goods. The cellular structure of EPS makes it dimensionally stable and therefore does not deteriorate with age. EPS is also odourless and non-toxic.
(3) Moisture Resistance
EPS is a closed cell material and does not readily absorb water. There is no loss of strength in damp conditions, making EPS ideal for cool-chain products. The material is moisture resistant, so the highest hygiene requirements are met. The ability of EPS to resist moisture also lends itself for use in fishing floats and marina buoys. Even when subjected to prolonged saturation in water, EPS will still maintain its shape, size, structure and physical appearance with only a slight reduction to its thermal performance.






Expanded polystyrene machine

Batch pre-expander

Including stainless steel dryer bed, screw conveyer, sieving device, etc

1.Steam system: Accurate pressure reducer and PID control system (proportional steam valve system) to keep very stable and accurate steam, ensure material variation;

2.Pressure control: Pressure sensor with multi-steam and exhausting system to keep expansion chamber pressure stably, also reduce the steam consumption;

3.Temperature control: Adopts temperature sensor and compressed air proportional valve to keep accurate expansion temperature, which is suitable for high density expansion, less broken beads;

4.Material level control: Keeps accurate weighing scales and vibrated level sensor control, ensure less density tolerance.

5.Weighing filling: Set filling weight in touch screen and electronic weighing filling to realize filling accurate and automatically;

6.Electric control: Adopts PLC programmable controller and touch screen, electronic parts, valves are famous brand, which control the whole working procedure automatically and stably.

FROM:Hangzhou Fangyuan

EPS Automatic Vacuum Packaging Machine Frame System3

(5)Hydraulic, pneumatic devices

The power of the molding machine is divided into hydraulic and pneumatic.

(6) Out of the rack

Product stripping, the need to use the top of the mandrel, the top of a rod connected to the top of the rack, one end contact products, the use of hydraulic cylinders, to promote the product out, and this time, the top of the spring was compressed, Due to the strength of the spring, the ejector is reset.

(7) Safety doors

As the molding machine clamping force is large, the staff once caught in the machine, the consequences could be disastrous, combined with both sides of the machine need to operate, often control the disk side of the operator is not easy to grasp the other side of the operation, it must set the security door, when the security door is open , The machine can not start, even if the movement of the machine, the security door opened, the machine will immediately stop the movement, the body, machinery, products play a protective role. As the machine has a memory function, so re-open the machine, the machine can continue to run by step.

EPS Foam Recycling Technology

EPS foam recycling technology recycling is the most important measures of environmental harm, recycling is also known as re-resource technology. At present, many scientific research units at home and abroad on the EPS recycling research, and some have reached the level of practical, large transport machine 02826240333 has reached the practical degree of several EPS recovery technology methods were described. First, the mechanical recycling This method can be divided into simple regeneration and composite regeneration of two, EPS foam mechanical simple regeneration is mainly used for the production of corners of the waste, but also easy to clean the recycling of disposable waste, its composition comparison Simple, clean, renewable materials can be used alone or in a certain proportion of the use of new materials can also be used in existing technology and equipment, is the main and effective use of the current method. 1. Recovery of production XPS EPS waste by pulverizing the material, the preparation of PS, and then heated by adding foaming agent, flame retardants, nucleating agents and other additives, processed by the system obtained XPS, widely used in building materials. At present, the recycling technology in the country has been a large area of promotion, and become one of the main ways EPS recycling (data query: Dachuan machine). 2. Recycling foam manufacturers can be scrap and unqualified products broken by crusher into a certain size of the particles, mixed with fresh pre-beads in the sheet metal forming machine or packaging machine in the molding, made of a variety of specifications and shape Of EPS products. After the production practice proved that the product performance to meet the national standard GBl0801-2002 under the premise of broken particles can be between 10% to 25%, that is, you can save raw materials 10% to 25%. 3. Hot melt regeneration, the use of foam pellet machine hot melt regeneration points the following process. One process is to waste EPS foam at 140 ℃ ~ 190 ℃ under constant temperature baking, so that shrinkage defoaming, foam plastic plant after cooling to crush. Baking will produce flammable gases, need to take effective measures to pay attention to production safety. Another process is to first break the scrap, and then the use of a screw propeller foam particles forced into the extruder barrel by heating and melting extrusion, pull, cooling, pelletizing into renewable particles, EPS foam plastic machinery Is the most practical.

How is EPS made?

EPS is produced in a three stage process:

(1) Pre-expansion

Upon contact with steam the pre-foaming agent found within the polystyrene beads (usually a hydrocarbon such as pentane) starts to boil and the beads are expanded to between 40 to 50 times their original volume.

(2) Conditioning

After expansion the beads undergo a maturing period in order to reach an equilibrium temperature and pressure.

(3) Moulding

The beads are placed within a mould and again reheated with steam. The pre-foamed beads expand further, completely fill the mould cavity and fuse together. The beads are moulded to form boards, blocks or customised products.

There are two moulding processes for EPS.

Block moulding produces large blocks of EPS which can then be cut into shapes or sheets for use in both packaging and construction applications.

Shape Moulding produces parts which have custom designed specifications. Electronic product packaging in particular is where shape moulded EPS is used extensively. When moulded, nearly all the volume of the EPS (~98%) is air.


EPS block molding machine

1.Machine structure:

a, The machine mould are welded by strong rectangle tube and steel plate with high strength frame, keep more safety of the machine;

b, All block mould frames are treated by heat-treatment to release the welding stress, so that the frames would not deformed;

c, After heating treatment, all mould frames are processed by sand blasting treatment to get rust prevention, so under coat and finishing coat are greatly improved anticorrosion performance and long life;

d, Adopts three Germany gauges and safety valve for multi-safety protection. The machine will be tested by water pressure and steam (many steps), ensure the machine more stable and safety.

2. Steam system: Three ball valves, comparing one big steam valve, saves 20% steam, with ISO-standard butterfly valves, greatly improve stability and long life;

3. Control system:

a, Adopts PLC(Mitsubishi) and touch screen (Schneider) with easily operation;

b, Equipped material level sensor to control the filling. The block cooling is controlled by foam pressure sensor; The whole procedure for filling, heating, cooling will be automatically by PLC.

EPS Automatic Vacuum Packaging Machine Frame System2

Vacuum pump

The steam in the product passes through the condenser, and the part is condensed into water, and the other part of the steam is pumped out by the vacuum pump to further cool the product. After the product is cooled by vacuum, the surface is very smooth. Vacuum cooling time, in the entire molding cycle accounted for a large proportion of the general accounted for 1/3. Vacuum pump is an important part of the vacuum system, although the traditional automatic molding machine has a vacuum system, but the cold water and vacuum condensate is not separated, and advanced equipment is used high temperature water (55 ℃) cold mold, low temperature water (25 ℃ ) Cool the vacuum pump. EPS molding temperature is about 115 ℃, cooling, the mold surface spray 55 ℃ cooling water 2 ~ 3s, so that the mold surface temperature dropped to about 90 ℃, and then start the vacuum pump began to vacuum. Due to lower pressure, the boiling point of water is also reduced, so the water products within the EPS product began to vaporize and be extracted from the body, and water vaporization is an endothermic process, which makes the cooling process is very rapid, to avoid the product outside the cold heat , And because of this method, the moisture content of the product is very low, generally only 60% to 8%.

Vacuum machine, but also divided into two separate vacuum and central vacuum two types of vacuum is a separate vacuum machine each with a vacuum pump; centralized vacuum, also known as the central vacuum, the machine itself without a vacuum pump, the vacuum machine provided by the vacuum station, the use of central vacuum , The molding machine to improve the efficiency of production, energy consumption is reduced, the central vacuum is the development direction of the current automatic machine.