Forefront of the market
Exhibition: 20th China International Adhesives & Sealant Exhibition
Risun Polymer Was Invited to HUI TIAN 2016 Core Suppliers Summit
Process Related Questions
1. Is there any special requirement about the equipments used to produce STP sealants?
Conventional equipments with functions of vacuuming, heating and cooling, high - speed dispersing can be used to produce the STP sealants.
The whole set of automatic production equipment can also be used, but the equipment investment is high.
2. Things that need to be paid attention and the specific requirements about the water control in production process.
There are many water control methods. The sealants factory can deal with it based on their actual situations. You can prebake or can heat, acuumize while mixing, add a little methanol to auxiliary dehydration, and add chemical dehydrating agent such as vinyl silane A171. However, we suggest having on line moisture monitoring equipments such as Karl Fisher moisture content testing equipment, and to use purging nitrogen as protection while adding fillers and polymer bystep. It is required to add polymer when the moisture is below 500ppm, add a little chemical dehydrating agent and keep away from moisture. Good package material (for example, paper tube with aluminium coating inside and outside, the aluminium coating thickness is no less than 8μm) can prolong the storage period.
3. How is the influence that the moisture made on the product? To what degree that the moisture will not influence the quality of the product.
The moisture can produce an effect on the validity period, and make some product hardening or viscosity much increased. In the process of making sealants, the moisture is required to be below 500ppm, and add a little chemical dehydrating agent such as A171 to prolong the storage period and avoid the quality decreasing of the product.
4. When making the sealants, add A171 together with thixotropic agent, stabilizer, UV resistant agent or add A171 first?
A171 will be added after the stabilizer (antioxidant) and UV resistant agent being added, and together with thixotropic. For DS series polymer, a little A171 can be added when mixing the polymer.
5. When to add the DIDP as plasticizer? How are the influences on hardness and flexibility made by DIDP? What component can be added to decrease the viscosity if DIDP is not available? Is there any other choice of plasticizer?
Add DIDP when mixing and dispersing other fillers. The more plasticizer are added, the lower the hardness will be. Other cheaper plasticizers such as DOP can also help to adjust the viscosity. But these plasticizers can not intermingle with polymer as well as DIDP does. If adding these plasticizers to much, they might exude. Our company supplies polymer with various ranges of viscosities for you to choose.
6. In the sample test, curing is slow, tensile strength is not very strong, the surface is sticky, what are the reasons?
These properties are not only affected by the polymer but also by other fillers, production process as well as bonding environment. Because the quality of our polymer is stable, maybe some more adjustments to formulations are needed.
By adding a little more catalyst or amino-silane coupling agent, the curing speed can be quickened, and the sticky problem can be lightened.
The strength is greatly influenced by fillers and dispersion effect. In the condition that the fillers are uniformly dispersed,using light calcium will have higher strength then heavy calcium. More polymer will also make the strength higher, but this will increase the cost.
We will be glad to make some advices and asist you in developing initial formulation.
7. The glass can not be bonded by the sealant. The surface of sealant is too sticky. Why?
What is the viscosity of the sealants? If the viscosity is high, add some quantity of plasticizer such as DIDP, which can intermingle well with our polymer. The DIDP will not exude after curing. If it is low, add some fumed silica if possible, do not add plasticizer.
The other fillers are seldom added in making crystal clear sealant, which causes the sticky of the surface. But we have tested in our side that the surface of sealant is just a little bit sticky. If it is very sticky in your side, try to consider and revise the quantities of catalyst, fumed silica and plasticizer.
No. 9 Zhangzhi Road, Huai'an Salt Chemical Industrial Park, Jiangsu
Risun Polymer International Co., Ltd.