# EVA 케이스란: 현대 전자기기에 필요한 보호 성능 탐구

Canonical URL: https://evacasemanufacturer.com/ko/news/what-is-an-eva-case-exploring-the-essential-protection-for-modern-electronics
Published: 2024-04-24 14:49:00
Author: Dongguan Lianping Luggage Co., Ltd.
Publisher: LIANPING
Keywords: what is an eva case, eva case meaning, ethylene vinyl acetate case, eva vs abs case, compression molding eva case, eva case density hardness, custom eva case manufacturer
Views: 2,939
Language: ko

EVA 케이스란 무엇이고 어떻게 성형하며, 어떤 밀도와 경도를 지정해야 하는지, ABS나 PP 성형이 더 나은 해답인 경우를 쉽게 설명합니다.

A first-time buyer in Toronto sent us a one-line email last month: what is EVA, and why is everyone quoting it instead of ABS? He had been sent three quotations for the same bluetooth speaker case and the prices differed by more than a dollar a unit. The short answer is that EVA is not one material but a family of closed-cell foam sheets, and the quote depends on which sheet, how thick, and what gets laminated on top.

## What EVA actually is

EVA stands for ethylene-vinyl acetate, a copolymer that is foamed into closed-cell sheet stock. Closed cell means the bubbles do not connect, so the sheet does not soak up water and it springs back after being squeezed. Sheet comes in densities that matter to a case buyer: roughly 0.15-0.18 g/cm3 for light sleeves, 0.18-0.22 g/cm3 for most consumer electronics shells, and 0.22-0.25 g/cm3 where the case has to resist crush in transit. Hardness is quoted on the Shore C scale, usually 40 to 70, and the two numbers are not interchangeable. A light, hard shell feels cheap and cracks at the corner; a dense, soft one slumps in a hot container.

## How the shell is made

The route we use is compression moulding: a cut sheet goes into a heated aluminium tool, the press closes, the sheet takes the shape and the trim is cut afterwards. Tooling for a compression-moulded EVA shell typically runs a fraction of an injection tool for the same part, which is why short runs make sense. Thermoforming is used for shallower trays and inserts where the wall does not need to carry load. Injection-moulded ABS or PP is the right answer when a customer needs a true right angle, a living hinge or volumes in the tens of thousands, and we quote that route too rather than forcing EVA into a job it does not suit.

- Laminates: 600D Oxford cloth, PU leather grain, velvet or flocked facing bonded to the inside face

- Interiors: die-cut EVA foam, egg-crate lid foam, elastic loops or a moulded tray

- Compliance: RoHS, REACH and CA Prop 65 declarations, with CTI reports tied to the production batch

Typical figures for a custom shell are 500 pieces minimum, tier pricing at 500, 1000 and 3000, and about three days to a first sample once the device is in the workshop. Electronics customers usually land in [the electronics accessory case range](https://evacasemanufacturer.com/ko/products/sub/eva-case-for-electronic-accessories) for small parts, or in a [tablet-sized shell](https://evacasemanufacturer.com/ko/products/sub/eva-tablet-case) once the device goes over about 8 inches. Everything we form is listed under [the EVA case category](https://evacasemanufacturer.com/ko/products/category/eva-cases), where the density and hardness figures are printed on each page rather than hidden in a spec sheet.

The Toronto buyer ended up at 0.20 g/cm3, Shore C 60, with an Oxford laminate and a die-cut cavity for the speaker and its cable. His revised quotation comes back on Monday with the foam die cost broken out separately.

## FAQ

**What does EVA stand for in EVA cases?**

EVA stands for ethylene-vinyl acetate, a copolymer foamed into closed-cell sheet. The closed-cell structure means it does not absorb water and springs back after compression, which is why it works as a protective shell. Cases are formed from this sheet by compression moulding, then trimmed and lined with fabric, foam or velvet.

**What density and hardness should I specify for an EVA case?**

Most consumer electronics shells sit at 0.18-0.22 g/cm3 and Shore C 55-65. Light sleeves run down to 0.15 g/cm3, while cases that get stacked in transit go to 0.22-0.25 g/cm3. Density and hardness are separate numbers: a light hard shell cracks at the corner, and a dense soft one slumps in a hot container.

**When is ABS or PP better than EVA for a case?**

Injection-moulded ABS or PP wins when you need a true right angle, a living hinge, a very tight tolerance stack or volumes in the tens of thousands, since the higher tooling cost spreads over more units. EVA wins on short runs, soft-touch surfaces and lighter weight. We quote both routes rather than pushing one.

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