Food grade Plastics - PPSU Processing

Food-grade plastics - PPSU processing of those things

PPSU Processing Blow Molding Steps

1.Raw material preparation

Prepare the right amount of PPSU granules which are dried and screened.

2.Melting

Put the PPSU particles into the high temperature melting equipment, heating to above its melting point, so that it completely melts into a viscous flow state.

3.Injection

The melted PPSU is injected into the cavity of the mold to form the desired shape of the blank.

4.Blow molding

Compressed air is injected into the preform to make it expand inside the mold and stick to the wall of the mold cavity, and form the desired container shape after cooling.

5.Demolding

The container is removed from the mold for subsequent finishing and processing.

6.Finishing

The appearance of the container is polished, cut or printed to improve its aesthetics and practicality.

7.Testing and Packaging

Conduct quality inspection on the containers to ensure that they are free from defects and then pack them for sale or use.

PPSU processing and molding conditions

1.Molding temperature

The melting point of PPSU is about 260°C, so the key to the molding process is to control the heating temperature. Ideal molding temperature is usually between 180 ° C to 230 ° C. The molding temperature can be too high or too low, which may cause the material to decompose. Too high or too low a temperature may lead to material decomposition or deformation.

2.Pressure and speed

Due to the poor fluidity of the melt of PPSU, the need for higher injection pressure (usually 150-400MPa) and slower injection speed (10-30mm per second) to ensure that the molten material can fully fill every corner of the mold.

3.Mold design

Due to the close molecular structure of PPSU and high crystallinity, the design should pay attention to avoid the melt in the cooling process of contraction and deformation. It is recommended to use a short runner, wall thickness of the mold design to ensure uniform filling and rapid cooling of the melt.

4.Post-processing

After molding PPSU plastic needs to be post-treatment, such as drying and curing, to remove residual moisture and volatiles, so that the material becomes more hard and stable.

5.Other Precautions

During the injection molding process, the injection speed and pressure, as well as the mold temperature and cooling conditions, should be strictly controlled to prevent the occurrence of bubbles, shrinkage and other problems. In addition, the poor fluidity of PPSU material requires the use of high viscosity screws and nozzles.

Characteristics of thermoforming for PPSU blister processing

1.Excellent material performance

PPSU has high heat resistance, chemical resistance and excellent mechanical properties, and can meet the needs of a variety of complex shapes and high demand for products.

2.Strong customizability

By adjusting the heating temperature, molding pressure and mold design and other parameters, you can manufacture products of different sizes, shapes and thicknesses. At the same time, can be added in the molding process, such as reinforcing bars, threads and other structures to improve the mechanical properties and functionality of the products.

3.Lower processing costs

Compared with injection molding and other molding processes, blister thermoforming equipment and mold costs are lower, and the production process consumes less energy, which helps reduce production costs.

4.Environmentally sustainable

PPSU is an environmentally friendly material that can be recycled. At the same time, the blister thermoforming process produces less waste, which is conducive to reducing environmental pollution.

5.Wide range of applications

PPSU blister thermoforming products can be used in medical, food, cosmetics, electronic products and many other fields, the market demand is high.

PPSU products processing common problems and their solutions

1.Appearance of air bubbles

Bubbles is a common problem of PPSU products is mainly due to the mold temperature is too high or the injection speed is too fast. The solution is to reduce the mold temperature, slow down the injection speed, and at the same time can increase the injection time and the second stage of the injection time, in order to allow the gas to have enough time to discharge the mold.

2.Shrinkage

PPSU products in the cooling process will appear shrinkage, if too much shrinkage will lead to product deformation. The solution is to increase the mold temperature in the process, slow down the cooling rate, and at the same time can be appropriate to increase the injection time and injection pressure, in order to allow the material to better fill the mold cavity.

3.Cracks cracks

Mainly due to unreasonable mold design or mold temperature is too low. The solution is to check whether the mold design is reasonable, if there is any problem timely modification. At the same time can be appropriate to improve the mold temperature and processing temperature, slow down the injection speed, in order to let the material flow better and fill the mold cavity.

4.The appearance of silver silver grain

Is due to excessive moisture or volatiles in the PPSU material, the solution is to check whether the material is dry, to ensure that there is no moisture or volatiles in the material. At the same time, you can appropriately increase the mold temperature and processing temperature, increase the injection time and injection pressure, in order to allow the material to flow better and fill the mold cavity.

5.The appearance of opacity or color inconsistency

Is due to the quality of PPSU material problems, the solution is to check whether the material is qualified, if any problem timely replacement. At the same time can be appropriate to increase the processing temperature and extend the processing time, in order to let the material better plasticization and uniform mixing.