LSR Mold, known as Liquid Silicone Mold, Silicone Injection Mold, LIM or Liquid Injection Molding, which is a new and advanced molding method compared to compression molding and transfer injection molding. LSR Mold has two types: LSR Mold with needle valve (shut-off )and LSR Mold without needle valve (shut-off). Normally for LSR Molding with needle valves is a standard Liquid Injection Mold, while because of the higher cost of the mold, LSR Mold without shut-off occurs. Let's move forward to see the diffrence of LSR Mold with needle valves and LSR Mold without needle valve. And what's the advantages and disadvantages of them.
Why some LSR molds need shut-off and some do not need?
Mainly depends on liquid silicone rubber products designs, quality requirements and quantity demands etc. For some baby care products, such as silicone baby bottle, silicone baby nipple, silicone breast pump, silicone baby pacifier, which do not need high dimension tolerance, mainly to make sure material safety. LSR Mold without needle valve is sufficient for production. While for some high precision silicone gasket and seals, needle valve is a must to make sure the dimension tolerance.
LSR Mold with Shut-off Valves
Advantage of Liquid Silicone Injection Mold with Shut-off Valves
With the control of needle valve, the material is well controlled in certain and accurate amount to each cavity, make sure there is not or less silicone rubber flashing on the product. Not only save material but also save trimming time.
LSR Silicone parts by Liquid silicone injection mold with needle valve have good quality and stable sizes and designs tolerances.
lSR Molded Liquid silicon injection products with low defect. Suit for LSR & liquid silicone mass production and semi-automatization and automatization.
Disadvantage of LSR silicone injection mold with shut-off valves
Shut-off valve is one kinds of mold standard parts, which is very expensive. The cost of one shut-off valve is about 500 to 800USD, some needle valve is more expensive is about 1000-2000 USD. The cost for one needle valve is equal to one compression mold. That's why the cost of LSR Mold is much expensive than compression molding. While If liquid silicone products want to achieve no silicone rubber flash, with high dimension tolerance, each mold cavity & chamber need one shut-off valves. The more shut-off the more expensive of the LSR Mold.
To save liquid silicone injection molding cost, some mold making factories will choose one shut-offer valves for two or four mold cavities & chambers. Some also choose cheap or homemade shut-off valves, whith cheap needle valve, the mold cost is cheaper, while the quality of liquid silicone rubber injection molded products is not good enough and dimension is not stable, especially after a certain quantity production. So mass production project, we will suggest to choose LSR mold with needle valves to make sure production smoothly.
LSR Mold without Shut-off Valves
Liquid silicone injection mold without shut-off valves, also called Open-ended Liquid Silicone Injection Mold, like edge-injection-gate plastic injection mold. Liquid silicone & lsr products have big injection gate mark or flow mark. This molded types mainly suit to produce big LSR silicon products like baby feeding bottle, produce not sizes and designs tolerances requirement like baby care products, or produce low-volume liquid silicone products.
Advantage of Liquid Silicone Injection Mold without Shut-off Valves
Save LSR injection molding cost
Suit for low-volume lsr injection molded
Suit for prototyping liquid silicone products
Disadvantage of Liquid Silicone Injection Mould without Shut-off Valves
Liquid silicone flow-mark or spot on LSR products
Injection gate is easy to be blocked when production
Difficult to control injected material amount.
Can't produce high precision liquid silicone rubber products & parts
Big liquid silicone rubber flashing, waste liquid silicon materials