Tear burrs are silicone products of a process, silica gel products in front and silica gel products to produce a common appearance bad, resulting in silicone products group of front too common causes of and solutions:
1, flash too thick
So the first thing to do is to think of a way to flash do thin - (for example, only do a few holes do not do full, do so out of as long as not mold or machine uneven edges is not thick) - and then to tear the thin look like tearing if thin tear. Find resulted in burr thickness, pressure? Or feed too much? Or die problem? Or a machine is not flat lead? Rubber liquidity bad back again. In fact compound flow well is not a big problem, bad fluidity generally the most common is a small part of the local material shortage and many spilled material, the analysis of the above problems can be solved burr thickness.
2, the exhaust number is too much (especially silicone rubber obvious)
Exhaust too much, the silica gel material that will not tear burr of tear, you let him with her nails in the torn edges at the pinch to try, in looking for a hacksaw bar sharpened, let him first pick a mouth in tearing the tear. Add mould design multi torn edge effects, torn edge design for vertical angle (the angle of 90 degrees) than the 45 degree angle tear, discharge chute do large usually smooth edges not thick, 45 degree angle of the nozzle width is too small depth is too small for the tear for easily broken tear groove edge angle is close to 90 degrees to tear out the beautiful burr is less, mold material more hard nozzle moonlight slippery sharp without gap torn edges more beautiful.
3, the die is incomplete, or lead to the flow lead to tear edge burr
Is a lot of burr or tear not moving? A lot of burr to see if there is a lot of holes in the mold hole, if not so you can find no defect of the few points to tear to see if there is no problem if you do not want to get into trouble if you don't want to repair the mold bar. Do not want trouble to repair the mold or mold repair is not convenient to see if there is no improvement in the formulation of the formula to see if there is no improvement (of course, is to allow the premise of the adjustment formula)
4, the curing system has led to a large number of silicone products
If the formula of soft carbon black content great but flash is not torn, then look at the vulcanizing system affect the curing system torn edges is mainly scorch the problem of period, the length of time. With CZDM; use less TT; it will be advantageous to you; the best is TT S TT as far as possible, the use of the little point; S use more than the point.
5, filling and reinforcing the problem caused the silicone products approved large
First of all look at the formulation of the filling weight and the type of carbon black reinforcing effect is better, can be added to the case of more than half fill (or other soft carbon black) dosage, will be very beneficial to tear off, also can solve the problem caused by improper packing. Like clay, calcium carbonate, talc, Baiyanhua filler, in comparison to the soft carbon black to regulate the torn edges much worse; semi reinforcing to regulate the torn edge problem suitable for the vast majority of silicone products, which can well solve the filling reinforcing problems lead to silica gel products in front of.