Why does the size of silicone products appear in the production of defective size?

Second, the pressure causes the poor load of the silicone button, resulting in the poor size of the silicone product.

Note: 1. When the molding pressure is too high, the size of the silicone product is too long.

2. When the pressure is too low, the size of the silicone product is too small and the thickness is too thick.

3. The weight of the molding rubber.

Silicone emits too much rubber, resulting in bubbles (air wrapping) of silicone products and high and poor load of silicone buttons, resulting in the size of silicone products being too large.

Note: The weight of the discharge rubber is on the low side, resulting in the small size of the silicone product after molding. Summary:

Poor size of silicone products is functional defect, different from the poor appearance of silicone products, once the size of silicone products is abnormal, it will face scrap treatment, and there is almost no possibility of repair. Therefore, special attention needs to be paid to controlling the occurrence of dimensional abnormalities in the production process of silicone products. Only when the cause is found, the problem will be solved.

Silicone emits too much rubber, resulting in bubbles (air wrapping) of silicone products and high and poor load of silicone buttons, resulting in the size of silicone products being too large Note: The weight of the discharging rubber is light, resulting in the size of silicone products being small after molding.

Silicone rubber: Silicone rubber (English name: silicone rubber) is a kind of silicon and oxygen polymer that can be obtained by controlling the length of the skeleton, the type of organic groups and the cross-linking of the skeleton.

Silicone rubber is divided into hot vulcanization type (high temperature vulcanized silica gel HTV) and room temperature vulcanization type (RTV), of which room temperature vulcanization type is divided into polycondensation reaction type and addition reaction type. High-temperature silicone rubber is mainly used to manufacture various silicone rubber products, while room temperature silicone rubber is mainly used as adhesives, potting materials or molds. Silicone rubber is sometimes referred to simply as silicone, but in English, silica gel and silicone are silicone-containing compounds with different properties and uses.

What are the reasons for the defects of silicone products? Please express it clearly: Is the size of silicone products not measurable?

1. The reason for the poor change in the size of extruded silicone products.

1.Mouth plate thickness. The thickness is small, the expansion rate is large, and the expansion rate is small when the thickness is large;

2.Head and mouth temperature. The expansion rate is small at high temperature, and the expansion rate is large at low temperature;

3.Extrusion speed. The extrusion degree is fast, the expansion rate is large, and the expansion rate is small by 4Plasticity. The plasticity is small, the expansion rate is large, and the plasticity is large, the expansion rate is large;

5.Glue content. The glue content is high, the expansion rate is large, and vice versa;

6.The temperature of the rubber compound is high, the expansion is small, and vice versa;

7.Rubber molecules containing branched functional groups such as benzene rings and butyl groups have a large expansion rate. For example, styrene-butadiene rubber, neoprene rubber and butyl rubber have a greater expansion rate than butadiene rubber and natural rubber.

8.The shorter the rubber stops for a while, the greater the expansion rate after use.

2. Reasons for the poor size change of other silicone products.

For the problem of poor change in the size of silicone products, it is relatively easy to solve, first determine the formula and process, then measure the size, and then adjust the mold according to the size. If the mold size is not good, it is useless for you to adjust the formula. At present, many rubber factories are relatively simple in the analysis of problems, and should be comprehensively considered from the aspects of man, machine, material, environment, method and measurement.

If the production process is the same, the weight of the blanking is the same, and the size is still unstable, the silica gel itself should be considered, the size of different batches of silica gel products is different, and the same batch will also have an impact on the size of the product if it is placed for too long, and at the same time control the rubber mixing process of the silica gel, because the length of the rubber mixing time and the different processes will cause changes in size. Tips for rubber mixing process.

I also saw it in Ribo Rubber, and you can also take a look.

Nowadays, from the perspective of science and technology, the sealing and protection technology of many products still has certain defects in the actual process, such as the waterproof sealing of our mobile phones, the waterproof sealing ring of automobile lamps, etc., and the sealing material is silicone and rubber material is our most common material, so the silicone sealing ring is used in many aspects of a type of seal, and there are often some unexpected functional problems in the sealing products during normal use, and the actual problem cannot be achieved, and the effect of the product cannot be shown. So what are the considerable factors that affect it?

Hardness and softness effects.

In many cases, according to the different softness of silicone products, the functionality and structure of the product can be completely changed, so in the process of use, due to the selection of different hardness and softness of the silicone sealing ring after the appearance of force, stretching, extrusion and other phenomena, the sealing ring will have some unavoidable problems, such as extrusion gaps, excessive force, too high hardness, product deformation without rebound and other factors.

Clearance issues. The gap problem can be divided into several factors, one is because of the problem of the rubber material, many silicone materials have poor resilience due to the formula, the problem of insufficient tensile force leads to the leakage of the gap caused by the lack of strength in the use process, and the processing problem of the silicone ring manufacturer, such as the product is brittle, resulting in the thin thickness of the product curl, which is prone to this problem, and the soft product causes the rubber to be unripe, and the gap problem occurs after long-term tensile compression.

Stress process. O-type silicone ring is generally installed in several places, groove, plane, convex groove, the installation method of each product is different, and its stress process will also affect the service life and function of the product, so in order to ensure the sealing performance, this storage will be reserved, and the different methods and stress degree of the silicone rubber sealing ring will be distinguished, such as the plane installation can be more or less in the degree of tightness of the deployment, the degree of stress between the concave and convex action, and the degree of reservation in the selection of size.

Compression permanent.

Another criterion for evaluating the sealing performance of a 0-ring is the compression permaform of the selected material. Under the action of pressure, the 0-ring as an elastic element produces elastic deformation, and as the pressure increases, permanent plastic deformation occurs. In general, to prevent permanent plastic deformation, the maximum permissible compression of the 0-ring is about 30% in static seals and 20% in dynamic seals.

When silicone seals are installed in trenches, they are subjected to tension or compression. If the tension and compression values are too large, the 0-ring section will be excessively enlarged or reduced, because the tensile l% will reduce the cross-section diameter by approx. For hole seals, the 0-ring is in tension and the allowable tensile force is 6%, and for shaft seals, the 0-ring is preferably compressed along its perimeter and the allowable perimeter is compressed at 3%.

In the case of processing on the same machine and the parameters of the machine, temperature and pressure have not changed, the time of mold release will affect the appearance and size of the product, so the product size deviation is very important for the control of the temperature time, because the mold time is not controlled within a certain time range, the vulcanization temperature of silicone products will increase, and the deformation will naturally occur, so the control of time during processing can not only ensure the same size of the product, but also ensure the quality of the productIf the time is not controlled, one time is long, and the other time is short, it will lead to various undesirable phenomena in the product.

Secondly, for the raw material reasons will lead to different sizes of the product, when using long-term placement of rubber materials, the vulcanized product feels different, and the viscosity of the product is relatively large, the tensile degree is stiff, and the size will naturally be different, this reason belongs to the failure of the vulcanizing agent for too long in the raw material, resulting in a decrease in fluidity performance, so if you want to maintain the size and shape of the product, start from the source, for silicone product manufacturers, there are many reasons that affect the product factors, in addition to the reasons for the machine and raw materialsThe impact of the mold on the product is also one of the main reasons, and different solutions can be used to deal with different problems.

A: In terms of characteristics and feel, the toughness and elasticity of silicone products are very good, not easy to be permanently deformed due to external forces, and the feel will be relatively smooth, while fake silicone products are easy to deform, and they are relatively rough to the touch, because there is no layer of grease on the surface of fake silicone.

B: In terms of characteristics, silicone products are non-toxic, tasteless and colorless products, with good texture and no harm to the human body, while general counterfeit silicone products are very good at achieving these effects, and fake and shoddy silicone products are generally toxic and pungent smell!

C: We can also distinguish between real and fake silicone by flame burning, counterfeit silicone products emit black smoke and the residue is black powder when burning, and real silicone products produce white smoke and white powder when burning, no matter what color the real silicone product burns.

First, the quality of silicone raw materials will lead to the difficulty of dismantling silicone products, poor quality silicone raw materials its toughness is insufficient, tear strength is also obviously insufficient, in the process of dismantling the edge must be difficult to dismantle.

Second, the product in the molding process is relatively thick, so the burr is actually relatively thick, and the increase in thickness will definitely lead to the difficulty of removing the edge.

Third, vulcanization environmental factors, vulcanization temperature should be appropriate, too high and too low will lead to difficult to dismantle the edge, at the same time, the vulcanization time also needs to be well controlled, too long vulcanization time will lead to brittleness of the product, vulcanization time is too short will lead to no effect of vulcanization link, so the vulcanization link must be controlled to resist the beam.

Fourth, the problems of the forming mold, if the mold self-dismantling design is unreasonable, the molding mold is used for too long, the molding mold is seriously worn, and the quality of the forming mold is not up to standard, it will lead to the difficulty of dismantling the edge after production molding.