How to use polyurethane sponge pore agent to improve the production process of soft foam products: from raw material selection to finished product inspection

February 28, 2025by admin0

How to use polyurethane sponge pore agent to improve the production process of soft foam products: from raw material selection to finished product inspection

Introduction

As a polymer material widely used in the fields of home, automobile, packaging, etc., the performance of polyurethane sponge directly affects the quality of the final product. In the production process of soft foam products, the selection and use of pore agents have a crucial impact on the pore rate, breathability, elasticity and other properties of the product. This article will discuss in detail how to use polyurethane sponge pore agent to improve the production process of soft foam products, from raw material selection to finished product inspection, and strive to provide relevant practitioners with a set of systematic and scientific guidance solutions.

1. Function and selection of polyurethane sponge pore opening agent

1.1 The function of pore opener

The pore opener mainly plays a role in regulating the foam structure in the production process of polyurethane sponges. By controlling the porosity of the foam, the porosant agent can significantly improve the breathability, elasticity and compression properties of the foam. Specifically, the functions of pore-opening agents include:

Adjust the foam structure: The pore opener can promote the bursting of bubbles inside the foam, forming an interconnected pore structure, thereby increasing the pore openness of the foam.
Improved breathability: Foams with high porosity have better breathability and are suitable for application scenarios where good ventilation performance is required.
Enhanced Elasticity: The pore agent can optimize the elastic modulus of the foam so that it can quickly return to its original state after being compressed.
Improving compression performance: By adjusting the pore rate, the pore agent can improve the compressive permanent deformation performance of the foam and extend its service life.

1.2 Selection of pore agent

Selecting the right pore opener is the key to optimizing the production process of soft foam products. Here are a few factors to consider when selecting a pore opener:

Types of pore openers: Common pore openers include silicones, surfactants and polymers. Different types of pore agents have different impacts on foam performance and need to be selected according to specific needs.
Domic of pore opening agent: The dosage of pore opening agent directly affects the pore opening rate of the foam. Too little dosage may lead to insufficient porosity, and too much dosage may lead to too loose foam structure.
Compatibility with raw materials: The pore-opening agent needs to have good compatibility with polyurethane raw materials to ensure that it can be evenly dispersed during the production process and avoid local uneven pores.
Environmental protection: With the increase in environmental protection requirements, choosing environmentally friendly pore openers has become an industry trend. Environmentally friendly pore openers can not only meet production needs, but also reduce environmental pollution.

1.3 Parameters of pore opening agent

The following are the main parameters of some common pore opening agents:

Pore-opening agent type	Main Ingredients	Applicable temperature range (℃)	Recommended dosage (%)	Environmental
Silicones	Dimethylsiloxane	20-80	0.5-2.0	High
Surface active agents	Sodium alkylbenzenesulfonate	15-70	1.0-3.0	in
Polymers	Polyacrylate	10-60	0.8-2.5	High

2. Optimization of production process of soft foam products

2.1 Raw material selection and ratio

The raw materials of soft foam products mainly include polyols, isocyanates, catalysts, foaming agents and pore opening agents. The selection and ratio of raw materials have a decisive impact on the performance of the final product.

Polyol: Polyols are one of the main raw materials for polyurethane foams, and their molecular weight and functionality directly affect the hardness and elasticity of the foam. Commonly used polyols include polyether polyols and polyester polyols.
Isocyanate: Isocyanate is another main raw material for polyurethane foam. Its type and amount directly affect the crosslinking density and mechanical properties of the foam. Commonly used isocyanates include TDI (diisocyanate) and MDI (diphenylmethane diisocyanate).
Catalytics: Catalysts are used to adjust the rate of polyurethane reactions. Commonly used catalysts include amine catalysts and organotin catalysts.
Footing agent: Foaming agent is used to generate bubbles during the reaction. Commonly used foaming agents include water, physical foaming agents (such as HCFC-141b) and chemical foaming agents (such as sodium bicarbonate).
Pore opening agent: As mentioned earlier, pore opening agent is used to adjust the pore opening rate of foam. Choosing the right pore opening agent is the key to optimizing the production process.

2.2 Production process

The production process of soft foam products mainly includes steps such as raw material mixing, foaming, maturation and post-treatment. The following are detailed instructions for each step:

2.2.1 Raw material mixing

Raw material mixing is the first step in the production of soft foam products. Its purpose is to evenly mix raw materials such as polyols, isocyanates, catalysts, foaming agents and pore agents. During the mixing process, the ratio and mixing time of each raw material must be strictly controlled to ensure the uniformity and stability of the reaction system.

2.2.2 Foaming

Foaming is the core step in the production of soft foam products. Its purpose is to generate bubbles through chemical reactions to form foam structures. During the foaming process, the reaction temperature and pressure must be strictly controlled to ensure the uniformity and stability of the foam structure.

2.2.3 Cultivation

Mature is an important step in the production of soft foam products, and its purpose is to further stabilize the foam structure through heat treatment. During the maturation process, the maturation temperature and time need to be strictly controlled to ensure the mechanical properties and dimensional stability of the foam.

2.2.4 Post-processing

Post-treatment is the next step in the production of soft foam products. Its purpose is to process the foam products into the desired shape and size through cutting, grinding and other processes. During the post-treatment process, the processing accuracy must be strictly controlled to ensure the dimensional accuracy and surface quality of the foam products.

2.3 Process parameter optimization

The following are the main process parameters that need to be optimized during the production process of soft foam products:

Process Steps	Main Parameters	Optimization Objectives	Recommended range
Raw Material Mix	Mix Time	Horizability	5-10 minutes
Foaming	Reaction temperature	Foam Structure	20-40℃
Mature	Mature temperature	Mechanical properties	60-80℃
Post-processing	Machining Accuracy	Dimensional Accuracy	±0.5mm

3. Finished product inspection and quality control

3.1 Finished product inspection items

The finished product inspection items of soft foam products mainly include porosity, breathability, elasticity, compression performance and dimensional accuracy. The following are detailed descriptions of each inspection item:

3.1.1 Porosity

The porosity rate is an important indicator to measure the degree of pore opening of foam products, and its height directly affects the breathability and elasticity of the foam. The determination of porosity is usually done by microscopic observation method or gas permeation method.

3.1.2 Breathability

Breathability is an important indicator for measuring the ventilation performance of foam products, and its height directly affects the comfort and service life of the foam. The gas permeability is usually determined by gas permeability or pressure difference method.

3.1.3 Elasticity

Elasticity is an important indicator for measuring the recovery performance of foam products, and its height directly affects the comfort and service life of the foam. The elasticity is usually determined by compression rebound or dynamic mechanical analysis.

3.1.4 Compression performance

Compression performance is an important indicator for measuring the compressive resistance of foam products, and its height directly affects the service life of the foam. The compression performance is usually determined by permanent compression deformation method or compression stress-strain method.

3.1.5 Dimensional Accuracy

Dimensional accuracy is an important indicator for measuring the processing accuracy of foam products, and its height directly affects the effectiveness of foam products. The measurement of dimensional accuracy is usually done by caliper measurement or three-coordinate measurement.

3.2 Quality control measures

To ensure the stability of the quality of soft foam products, the following quality control measures are required:

Raw Material Quality Control: Strictly control the quality of each raw material to ensure that it meets production requirements.
Process parameter control: Strictly control each process parameter to ensure that it is within the optimization range.
Finished product inspection control: Inspection strictly in accordance with the finished product inspection items to ensure that it meets quality standards.
Production process monitoring: Monitor the production process in real time and promptly discover and solve problems in production.

3.3 Finished product inspection standards

The following are the main finished product inspection standards for soft foam products:

Inspection items	Examination Method	Qualification Criteria
Porosity	Microscopy Observation Method	≥90%
Breathability	Gas permeation method	≥500L/m²·s
Elasticity	Compression rebound method	≥80%
Compression Performance	Compression permanent deformation method	≤10%
Dimensional Accuracy	Calver measurement method	±0.5mm

IV. Conclusion

The rational selection and use of polyurethane sponge pore agent can significantly improve the production process of soft foam products and improve the porosity, breathability, elasticity and compression performance of the product. From raw material selection to finished product inspection, every link needs to be strictly controlled to ensure the stable quality of the final product. I hope that the systematic discussion in this article can provide useful reference for relevant practitioners and promote the continuous optimization and progress of the production process of soft foam products.