Products made of silicone rubber must be produced with the highest level of efficiency possible. There are several procedures that can satisfy the fabricant's demands. Here, the benefits and drawbacks of injection molding and transfer molding are contrasted.
射出成形
What is Injection Molding？
injection molding is a molding procedure that is distinguished by the use of injection technology. Because raw material is injected into a mold cavity, it is known as "injection molding." A screw pushes the material into a hopper during the injection molding process. The substance is heated before being put into the cavity of the mold. Compression molding and injection molding both employ heat and pressure to create their finished products. Injection molding and compression molding both transport the material via hoppers and screws, however injection molding does not.
Injection Molding Process
Here is how the procedure for injection molding works:
- A heated barrel is used to feed the material, which is frequently in the form of pellets or granules, and heat it to a molten condition.
- A reciprocating screw or ram injector forces the liquid material into the mold cavity and into a path known as a sprue.
- The melt is kept inside the mold and either heated to cure (for thermoplastics) or cooled to harden it (熱硬化性樹脂).
- Until the substance has hardened, the mold is opened and the element is ejected.
Injection Molding Advantages
For both silicone and plastic goods, injection molding is the most economical molding technique. This technology offers special benefits.
- Perfect Materials: Liquid thermosets or molten thermoplastics can readily flow into mold cavities. Faster cavity filling and quick cure are the results.
- Greater Capacity: Because injection molding machines can fit more cavities into a single mold, more units can be produced during each manufacturing cycle.
- Minimal Waste: Because the sprues are smaller and there are no overflow channels, there is less material waste as compared to transfer molding and other molding techniques.
- Rapid: The typical injection molding cycle time ranges from 2 seconds to 2 minutes. Compared to other molding techniques, this is quicker.
Injection Molding Disadvantages
The following are some drawbacks of injection molding as opposed to compression molding:
- High injection pressures for plastic are necessary for injection molding. In order to endure these intense pressures, the mold must be constructed. The tooling now costs more as a result.
- Making huge, thin items like automobile panels with injection molding is not a good idea.
Common Materials of Injection Molding
Injection molding is suitable for both thermoplastic and thermosetting materials, the common materials include:
- 液状シリコーンゴム (LSR)
- ポリスチレン (PS)
- ポリアミド (PA)
- ポリエチレン (PE)
- ポリ塩化ビニル (PVC)
- Acrylonitrile Butadiene Styrene (ABS)
- ポリプロピレン (PP)
トランスファー成形
トランスファーモールドとは何ですか？
トランスファー成形は、熱硬化性材料を使用して閉じた金型内でコンポーネントを作成する方法です。熱硬化性材料は、加圧下および高温下でランナーとゲートを介して閉じたキャビティに押し込まれます。, トランスファーポットとして知られる補助チャンバーからのプラスチック状態.
トランスファーモールドプロセス
トランスファーモールド法は射出成形と全く同じです, いくつかの重要な例外を除いて. Following are the steps:
- 材料はトランスファーポットとして知られる保持チャンバーに入れられます。, 温められているか、温められていない可能性があります.
- 材料は、スプルーとして知られるチューブを通って油圧で推進されるプランジャーによって金型キャビティに押し込まれます。.
- 物質は金型内に保持され、金属合金を硬化させるために加熱されるか、熱可塑性プラスチックを硬化させるために冷却されます。 (熱硬化性樹脂). アイテムが硬化した後もスプルー内に残っているマテリアルはすべてそれにリンクされます。.
- Once the material has set, 型が開いた状態, そして部品が排出される.
- The sprue's extra material is taken out.
トランスファーモールディングの利点
The preheating of the material and injection through a small aperture increase the temperature distribution inside the material and speed up the crosslinking process, which is one of transfer molding's benefits.
- 金型のパーティングラインでのバリの発生を最小限に抑えます。.
- セットアップ時間の短縮.
- 工具コストの削減.
- 部品設計の柔軟性が向上 (部品の複雑さに対応できる能力).
トランスファー成形の欠点
トランスファー成形には、使いやすさと速度の点でいくつかの欠点があります。:
- 材料廃棄物: スプルーとオーバーフロー チャネルのサイズが大きいため, トランスファー成形では追加の材料廃棄物が発生します.
- 生産が遅い: Transfer molding's production pace is slower than injection molding because materials must be heated prior to molding.
- 少量: トランスファー成形機は多くのキャビティを処理できないため、射出成形機よりもサイクルごとに作成する個数が少なくなります。.
トランスファー成形の一般的なポリマー材料
トランスファーモールディングは熱硬化性材料と熱可塑性材料の両方を適用できます, 最も一般的なポリマー材料には次のものがあります。:
- 不飽和ポリエステル
- エポキシ
- フェノールホルムアルデヒドプラスチック
- シリコーンゴム
Injection Molding Vs Transfer Molding: What’s the Difference?
The procedures are where these two moldings diverge most. Transfer molding and injection molding use plungers to drive materials into the molds, それぞれ.
There are several distinctions between injection molding and transfer molding that affect how final goods are produced. The following are the most important distinctions to take into account:
Molding Method Selection
There are a number of considerations we should address when deciding which molding technique is best for fabricating parts.
- A different type of machinery is used in transfer molding to provide pressure to the piston; this press is less expensive than an injection molding equipment. Transfer molding requires less money up front as a result. Small and medium-sized items are better suitable for transfer molding since the press produces less pressure than an injection molding machine.
- Cavitation Limitation: The press or injection molding machine's capacity determines how much cavitation may occur in a mold. The injection molding machine often has larger cavity space. 結果として, the cost per unit will drop and high-volume production will run more smoothly.
- Preparation of Raw Materials: In injection molding, we have ready access to raw materials (compounds A and B). Prior to inserting the raw materials in pots, we must prepare them in a number of procedures for transfer molding. This will lengthen the transfer molding process cycle time and ultimately raise the cost of production.
- 材料廃棄物: Transfer molding produces more waste than injection molding because of bigger sprue, more air holes, and overflow grooves. さらに, additional processes including trimming, cryogenic tumbling, and precise grinding are required to eliminate these wastes.
Injection Molding Vs Transfer Molding: Which Is Better For Your Product?
Although injection molding and transfer molding share many similarities, their differences are crucial in determining which method is best for producing a specific product. The following are the most important differences to consider when deciding which method to use:
Initial Investment
Both processes require a toolmaker or machinist to build molds, which is an expensive process. しかし, the cost of the machinery involved is the biggest factor in determining startup costs. The injection molding machine is significantly more expensive than the press needed for transfer molding, primarily because of the complexity and specialization of the components within the machine.
It also takes much more time to set up compared to a transfer mold machine, which means it will take longer for a project to get underway. The cost and complexity also mean that maintenance costs are substantially higher for injection molding machines.
Speed Of Production
Injection molding has a very short process cycle, running anywhere from two seconds to two minutes, depending on the size of the product. The overall production time increases with the removal of any excess material, such as flash or the sprue, but is still much shorter than the production time for transfer molding. The primary disadvantage in transfer molding is that the material is prepared before placement in the machine, increasing the time of the cycle significantly.
Cost Of Production
Cost of production does not typically favor one method over the other in all cases, but instead depends on the geometry of the product. Materials requiring a high injection pressure would require a more powerful injection machine, meaning it would be more expensive to use an injection machine instead of a transfer machine.
The same can be said for a larger part. しかし, injection machines can accommodate more cavities, increasing the production per cycle. Injection molding also involves more automation than transfer molding machines, meaning long-term labor costs are reduced significantly for high-quantity projects.
Product Shape And Accuracy
Both processes allow for impressive accuracy, and both provide very consistent results. しかし, injection molding doesn’t handle sharp edges very well and can end up rounding off edges that were meant to be sharp. さらに, even though both processes can produce units with very complex forms, the cost of doing so with transfer molding is significantly lower than with injection molding, primarily because complex injection molds require more intricate and expensive injection systems to produce.
Amount Of Waste
Although flash and sprue waste does happen with injection molds, transfer molding produces much more waste on average. This is primarily due to the presence of a wider sprue, air holes, and overflow grooves that are not present in injection molds. If the material involved is thermosetting, this can result in substantial material waste.
Product Size
Both of these methods operate well for small- to medium-sized products, but injection molding has the capacity to create much larger products, まで 80 square feet. Transfer molding is best suited to small and medium part sizes, primarily due to limitations in press sizes.
Product Volume
Injection molding is much better suited to higher quantities of larger, thin-walled parts, while transfer molding is better suited to encasements and small quantities of simpler molds.
In terms of the quantity of products desired, injection molding is vastly superior to transfer molding. The relatively automated systems, combined with faster cycle times, make this method much more cost-effective in the long run for high-volume projects.
We summarize the main information of liquid silicone injection molding vs transfer molding as following
— disadvantage, + advantage
Transfer Molding Vs Injection Molding FAQs
What is transfer Moulding used for?
トランスファー成形, which differs slightly from conventional compression molding, is frequently used for thermoset materials. It combines the processes of compression molding and injection molding. In this procedure, a holding chamber known as the pot is used to preheat the polymer.
What is the difference between compression transfer and injection moulding?
Compression molding is more suited to pliable and flexible materials, while injection molding is better suited to big volume production. さらに, tooling costs for compression molding are lower.
What is another name for transfer Moulding?
Similar to compression molding, transfer molding (BrE molding) involves measuring and inserting the proper amount of the molding compound, which is often a thermoset plastic, prior to the molding process. The molding compound is heated beforehand and loaded into the "pot," a chamber.
What products are made by transfer molding?
Manufacturers can encase components like integrated circuits, プラグ, connections, pins, coils, and studs using transfer molding. Transfer molding can produce materials with electronics, ceramic, or other inserts in addition to metal inserts.
4種類の成形とは?
- 圧縮成形.
- Melt Molding.
- トランスファー成形.
- 射出成形.
結論
There are a number of elements to consider when choosing the optimal method for producing a given product. As was already noted, before injecting or transferring the polymer to create the pieces, both transfer molding and injection molding allow the introduction of inserts (metal, fibers, or ceramic) in the cavity. The equipment utilized for each procedure varies, though. While an injection molding machine is used for injection molding, a press applies pressure to the piston during transfer molding. The initial expenditure for transfer molding is lower since a press is less expensive than an injection molding machine. Also, because transfer molding does not need more complicated systems, such the intricate expulsion system used in injection molding, the cost of the mold is lower. Because of this, transfer molding maintenance expenses are also lower.
Although both methods are capable of creating items with intricate geometries, injection molding machines often have more cavity space, which lowers unit costs and increases efficiency. Transfer molding is less advantageous than injection molding in several ways, though. 例えば, transfer molding requires that the material be ready before going into the pot, which extends processing time and raises production costs. さらに, wider sprues, air holes, and overflow grooves in transfer molding result in more waste. Further procedures including cutting, cryogenic, tumbling, and precise grinding are used to remove this waste.
結論は, both injection and transfer molding processes can produce high-quality products in similar ways. しかし, injection molding is better suited for parts that require precise intricacies and consistency, while transfer molding is better suited for simpler molds with faster tool builds.