内页底部

All rights reserved:Yangzhou EverGrowing EPS Products Co., Ltd., 苏ICP备15000201号-1 Powered by www.300.cn

>
New_detail
company news
Industry News

News

——

Method for improving cold ripening high resilience molded foam products

Page view
[Abstract]:
1IntroductionPolyurethanecold-curedmoldedfoamproductsaremainlyusedintheproductionofautomobileseatsandheadrests.Comparedwithhotmoldedproducts,theyhavesimpleprocessingtechnology,moderatemoldtemperature(
1 Introduction
Polyurethane cold-cured molded foam products are mainly used in the production of automobile seats and headrests. Compared with hot molded products, they have simple processing technology, moderate mold temperature (45-70 °C), low energy consumption, and excellent physical properties. Short mold time and high production efficiency. However, with the rapid development of the economy, especially in recent years, China's automobile production and sales have been the world's number one for four consecutive years, and in 2012 it exceeded 19 million. The competition with the car interior companies is becoming more and more fierce. The cost of land rent, human resources, raw materials and transportation is constantly rising, but it is difficult to digest the increased cost in the price of the products. Faced with the difficulties of reality, companies can only gain the space to continue to survive and profit by changing. The rapid demolding and high-performance system materials can greatly reduce the labor cost, and can reasonably reduce the density of the product under the premise of ensuring the physical properties of the product, thereby generating a new profit point.
 
2. Introduction
For many years, most of the cold-cured high-rebound products used TM20 (TDI/PAPI=80:20), TM50 (TDI/PAPI=
50:50) The production of TDI-rich mixed isocyanate is advantageous in that the TDI-rich NCO content is high, the low P/I ratio can reduce the amount of black material, and the cost is low; the foam produced by TDI is rich, Good elasticity, high tear strength, good fluidity of the system material, and relatively low product density. Disadvantages are that pure TDI is currently a drug, subject to the control of the Ministry of Public Security; TDI has a certain impact on the health of field operators; the system rich in TDI is slow to mature, affecting production efficiency; the foam rich in TDI production is soft.
Due to the low price of TDI in recent years, the cost of TDI-rich isocyanate is very cost-effective, and from the perspective of operator health, the amount of TDI needs to be reduced. The TM50 system is a relatively moderate ratio: physical property, moderate cost, and convenient procurement. However, it is still necessary to solve the problem that the slowness of ripening is slow, the high-physical foam cannot be satisfied, and the density is slightly large.
In general, the slow aging can be solved by increasing the foaming catalyst A1 and the gel-type catalyst A33. However, increasing the amount of A33 causes the foam gel to be too fast, which is less likely to be caused by mold clamping or product flow dissatisfaction, lack of angle, Poor phenomena such as voids, and easily lead to shrinkage of the product, flatulence, affecting the performance of the foam.
The physical properties of the foam are generally set by the OEM. In recent years, the OEM has also continuously improved the physical properties. The most common physical properties such as tear strength shall not be less than 2.0 N/cm, and the high requirements shall be greater than 2.3-2.5 N/cm; The tensile strength should not be lower than 90Kpa, and the high requirement should be greater than 100-120Kpa. The compression set is increased from less than 10% to less than 5%. Under the condition that the isocyanate is relatively fixed, it is necessary to carry out research from the combined polyether component, and select a suitable polyether, a polymer polyol and a crosslinking agent, a silicone oil, a catalyst, and the like.
Density is generally set by the OEM, but the general OEM will give a certain range. For example, some host manufacturers require 45±5Kg/m3. If the density can reach the performance requirements of the OEM in the 40-42 density range, This also reduces costs. Generally reducing the density is achieved by adding water. Water is a chemical blowing agent that reduces the density of the product by reacting with isocyanate to form a CO2 generating gas. However, if the water is too much, the water-isocyanate reaction (blowing reaction) in the system is greater than the polyol-isocyanate reaction (gel reaction), resulting in peeling, central voiding, and even collapse.
Therefore, in the selection of a relatively fixed isocyanate system, another major raw material is polyether, polymer polyol, and fixing a polyether system is beneficial to cost control. Considering the basic performance requirements and cost factors of the current OEM, polyether polyols can choose from 4800 molecular weight to 6000 molecular weight, polymer polyols can choose 3628 (28% solid content), H45 (43% solid content) and other common commonly used. Types, domestic manufacturers such as Shanghai Gaoqiao, Tianjin San Petrochemical, Jinpu Jinhu, Zhongshan Petrochemical, Shandong Dongda and so on. Setting up such standard polyether products is easy to purchase, the price is transparent, the supply chain is smooth, and the entire cost is easier to control.
In the selection of fixed isocyanate and polyether systems (330N to POP ratio), it is necessary to improve physical properties and process performance, mainly relying on new additives. This article focuses on the impact of additives on the overall foam properties and process conditions, because the proportion of additives in the entire system is low, through the application of additives, to give the foam a new vitality with minimal cost.
 
3. Experiment
3.1 Main raw materials and equipment
Isocyanates:
Toluene diisocyanate Lupranate TDI BASF products
Polyphenylpolymethylene polyisocyanate Suprasec 5005 Huntsman products
Polyethers:
Polyether Polyol EP-330N Shandong Dongda Company Products
Polymer Polyol POP-93/28 Shandong Dongda Company Products
Silicone oil:
TEGOSTAB® B 8738 LF2 Evonik Degussa products
Catalysts: ALLCHEM is a product of Shanghai Yuxing Industrial Co., Ltd.
ALLCHEM A-1 70% bis(2-methylaminoethyl ether) "BDMAEE" + 30% dipropylene glycol "DPG"
ALLCHEM A-33 33% triethylene diamine "TEDA" + 67% dipropylene glycol "DPG"
ALLCHEM DY-7 new complex amine catalyst
ALLCHEM DY-9 new complex amine catalyst
 
3.2 Formulation and Process
3.2.1 Pre-formulation of isocyanate B component
 
Component raw material (weight fraction)
formula
Lupranate TDI
50
Suprasec 5005
50
 
3.2.2 Experimental equipment Manual agitator, rotating speed 2000 rpm / min; through circulating water aluminum mold, size 400mm * 400mm * 100mm; super constant temperature water bath, control mold temperature 55 ° C; A, B component material temperature 25 ° C test;
3.2.3 Preparation method According to the A component: B component = 100:55 (weight ratio), the isocyanate index is 100. After rapid stirring, pour into the mold, close the mold, and take the mold after curing. The appearance of the skin is good, no Peeling and bad phenomena, the foam does not shrink.
3.2.4 physical property test standard product density according to GB/T6343-2009 method; indentation load according to GB/T10807-2006 method; elongation according to GB/T6344-2008 method; tear strength according to GB/T10808-2006 Method determination; compression set is determined according to GB/T 6669-2008 method
 
3. Experiment
3.1 Main raw materials and equipment
Isocyanates:
Toluene diisocyanate Lupranate TDI BASF products
Polyphenylpolymethylene polyisocyanate Suprasec 5005 Huntsman products
Polyethers:
Polyether Polyol EP-330N Shandong Dongda Company Products
Polymer Polyol POP-93/28 Shandong Dongda Company Products
Silicone oil:
TEGOSTAB® B 8738 LF2 Evonik Degussa products
Catalysts: ALLCHEM is a product of Shanghai Yuxing Industrial Co., Ltd.
ALLCHEM A-1 70% bis(2-methylaminoethyl ether) "BDMAEE" + 30% dipropylene glycol "DPG"
ALLCHEM A-33 33% triethylene diamine "TEDA" + 67% dipropylene glycol "DPG"
ALLCHEM DY-7 new complex amine catalyst
ALLCHEM DY-9 new complex amine catalyst
 
3.2 Formulation and Process
3.2.1 Pre-formulation of isocyanate B component
 
Component raw material (weight fraction)
formula
Lupranate TDI
50
Suprasec 5005
50
 
3.2.2 Experimental equipment Manual agitator, rotating speed 2000 rpm / min; through circulating water aluminum mold, size 400mm * 400mm * 100mm; super constant temperature water bath, control mold temperature 55 ° C; A, B component material temperature 25 ° C test;
3.2.3 Preparation method According to the A component: B component = 100:55 (weight ratio), the isocyanate index is 100. After rapid stirring, pour into the mold, close the mold, and take the mold after curing. The appearance of the skin is good, no Peeling and bad phenomena, the foam does not shrink.
3.2.4 physical property test standard product density according to GB/T6343-2009 method; indentation load according to GB/T10807-2006 method; elongation according to GB/T6344-2008 method; tear strength according to GB/T10808-2006 Method determination; compression set is determined according to GB/T 6669-2008 method