Comparison and selection method of hard foam silicone oil
The selection of the type and the definition of the dosage of the hard foam leveling agent (hereinafter referred to as “silicone oil”) are of great importance, which is directly related to the actual performance advantages and disadvantages of the foam final product such as the pore structure, anti-shrinkage, and heat preservation, etc. The selection of the type and the definition of the dosage of the hard foam leveling agent is a very important matter.
Experimental Objects
Conventional hard foam silicone oil in use as reference A, compared with unknown performance hard foam silicone oil B, C, D, E, etc.
Test apparatus
(Here only focus on listing the parts that are different from the conventional test)
1, variable speed electric drill: 300w or so, available knob gear to adjust the speed.
2, about 100ml size of disposable transparent plastic drinking cups: to be a little hard, lest the mixing time to hold the deformation is difficult to hold.
Blank mother liquor preparation example
First, high moisture, low density type handmade slow material
Polyether 4110: 100
Water: 1.8
Cyclohexylamine: 1.0~2.0 (depending on the ambient temperature and material temperature control)
141B: 25
Second, low moisture, high density type manual slow material
Polyether 4110: 100
Water: 0.5
Cyclohexylamine: 1.0~2.0 (depending on the ambient temperature and material temperature control)
141B: 7
The total amount of the above blank material preparation depends on the number of types of silicone oil to be compared with the whole n times enlargement. Shake well and divide into n equal parts.
Foaming
I. High moisture, low silicone oil, low density type handmade slow material
Will n equal parts of the blank material were added to 0.5 parts of the A, B, C, D silicone oil, fully shaken well after standing, to see its compatibility and transparency.
Adjust the speed of the variable speed drill to the appropriate gear: make sure that the mixing speed belongs to the “medium-slow” state, and absolutely do not allow high shear fast mixing.
Foam the components with 0.5 parts of silicone oil at the same speed, in the same proportion (about 12g of white material + 12g of black material) and at the same mixing time within 20 minutes.
Reminder: do not break the mushroom head whole crooked. After foaming and shaping can only be done at the bottom of the cup respectively mark in order to compare objectively and fairly.
Second, low moisture, low silicone oil, high density type handmade slow material
Operation with (i), about 20 grams of white material + 20 grams of black material
Third, high moisture, high silicone oil, low density type handmade slow material
The test (i) in the remaining white material in proportion to the respective amount of silicone oil to 1.0 parts, and then the same conditions foaming
Low moisture, high silicone oil, high density type handmade slow material
Test (ii) in the remaining white material of each paragraph in proportion to the amount of silicone oil to 1.0 copies of their respective, and then the same conditions foaming
[Comparison, analysis
Mix the foams in test one together with the naked eye to separate out the apparent bubble superiority or inferiority (bubble density, uniformity), and then look at the bottom to determine the ranking of these silicone oils.
Will test three in the foam mixed together with the naked eye to separate out the apparent vesicle superiority or inferiority (vesicle fine density, uniformity), and then look at the bottom to determine the ranking of these silicone oils.
And then put the same silicone oil model in the first and third experiments of different amounts of foam put together to compare, to see the amount of silicone oil to increase the density of bubble holes, the uniformity of whether there are obvious improvements
The same between two and four
If necessary, we can use the sharp edge cutting section to compare the internal bubble holes
Special Note
Normally, the silicone oil with good vesicles under slow mixing has superior vesicle performance under high shear mixing, especially the combination of materials to resist “abnormal fluctuations in process parameters during injection molding production” (e.g., fluctuations in power supply voltage, power frequency abnormalities, minor clogging, abnormal viscosity of the material) ability to be a little better.
